tests/suites/test_suite_ssl.function

/* BEGIN_HEADER */
#include <mbedtls/ssl.h>
#include <mbedtls/ssl_internal.h>
#include <mbedtls/ctr_drbg.h>
#include <mbedtls/entropy.h>
#include <mbedtls/certs.h>
#include <mbedtls/timing.h>
#include <mbedtls/debug.h>
#include <ssl_tls13_keys.h>

#include <constant_time_internal.h>

#include <test/constant_flow.h>

#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) || \
    defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \
    defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
#define MBEDTLS_CAN_HANDLE_RSA_TEST_KEY
#endif

enum {
#define MBEDTLS_SSL_TLS1_3_LABEL(name, string)   \
    tls1_3_label_ ## name,
    MBEDTLS_SSL_TLS1_3_LABEL_LIST
#undef MBEDTLS_SSL_TLS1_3_LABEL
};

typedef struct log_pattern {
    const char *pattern;
    size_t counter;
} log_pattern;

/*
 * This function can be passed to mbedtls to receive output logs from it. In
 * this case, it will count the instances of a log_pattern in the received
 * logged messages.
 */
void log_analyzer(void *ctx, int level,
                  const char *file, int line,
                  const char *str)
{
    log_pattern *p = (log_pattern *) ctx;

    (void) level;
    (void) line;
    (void) file;

    if (NULL != p &&
        NULL != p->pattern &&
        NULL != strstr(str, p->pattern)) {
        p->counter++;
    }
}

/* Invalid minor version used when not specifying a min/max version or expecting a test to fail */
#define TEST_SSL_MINOR_VERSION_NONE -1

typedef struct handshake_test_options {
    const char *cipher;
    int client_min_version;
    int client_max_version;
    int server_min_version;
    int server_max_version;
    int expected_negotiated_version;
    int pk_alg;
    data_t *psk_str;
    int dtls;
    int srv_auth_mode;
    int serialize;
    int mfl;
    int cli_msg_len;
    int srv_msg_len;
    int expected_cli_fragments;
    int expected_srv_fragments;
    int renegotiate;
    int legacy_renegotiation;
    void *srv_log_obj;
    void *cli_log_obj;
    void (*srv_log_fun)(void *, int, const char *, int, const char *);
    void (*cli_log_fun)(void *, int, const char *, int, const char *);
    int resize_buffers;
} handshake_test_options;

void init_handshake_options(handshake_test_options *opts)
{
    opts->cipher = "";
    opts->client_min_version = TEST_SSL_MINOR_VERSION_NONE;
    opts->client_max_version = TEST_SSL_MINOR_VERSION_NONE;
    opts->server_min_version = TEST_SSL_MINOR_VERSION_NONE;
    opts->server_max_version = TEST_SSL_MINOR_VERSION_NONE;
    opts->expected_negotiated_version = MBEDTLS_SSL_MINOR_VERSION_3;
    opts->pk_alg = MBEDTLS_PK_RSA;
    opts->psk_str = NULL;
    opts->dtls = 0;
    opts->srv_auth_mode = MBEDTLS_SSL_VERIFY_NONE;
    opts->serialize = 0;
    opts->mfl = MBEDTLS_SSL_MAX_FRAG_LEN_NONE;
    opts->cli_msg_len = 100;
    opts->srv_msg_len = 100;
    opts->expected_cli_fragments = 1;
    opts->expected_srv_fragments = 1;
    opts->renegotiate = 0;
    opts->legacy_renegotiation = MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION;
    opts->srv_log_obj = NULL;
    opts->srv_log_obj = NULL;
    opts->srv_log_fun = NULL;
    opts->cli_log_fun = NULL;
    opts->resize_buffers = 1;
}
/*
 * Buffer structure for custom I/O callbacks.
 */

typedef struct mbedtls_test_buffer {
    size_t start;
    size_t content_length;
    size_t capacity;
    unsigned char *buffer;
} mbedtls_test_buffer;

/*
 * Initialises \p buf. After calling this function it is safe to call
 * `mbedtls_test_buffer_free()` on \p buf.
 */
void mbedtls_test_buffer_init(mbedtls_test_buffer *buf)
{
    memset(buf, 0, sizeof(*buf));
}

/*
 * Sets up \p buf. After calling this function it is safe to call
 * `mbedtls_test_buffer_put()` and `mbedtls_test_buffer_get()` on \p buf.
 */
int mbedtls_test_buffer_setup(mbedtls_test_buffer *buf, size_t capacity)
{
    buf->buffer = (unsigned char *) mbedtls_calloc(capacity,
                                                   sizeof(unsigned char));
    if (NULL == buf->buffer) {
        return MBEDTLS_ERR_SSL_ALLOC_FAILED;
    }
    buf->capacity = capacity;

    return 0;
}

void mbedtls_test_buffer_free(mbedtls_test_buffer *buf)
{
    if (buf->buffer != NULL) {
        mbedtls_free(buf->buffer);
    }

    memset(buf, 0, sizeof(*buf));
}

/*
 * Puts \p input_len bytes from the \p input buffer into the ring buffer \p buf.
 *
 * \p buf must have been initialized and set up by calling
 * `mbedtls_test_buffer_init()` and `mbedtls_test_buffer_setup()`.
 *
 * \retval  \p input_len, if the data fits.
 * \retval  0 <= value < \p input_len, if the data does not fit.
 * \retval  -1, if \p buf is NULL, it hasn't been set up or \p input_len is not
 *          zero and \p input is NULL.
 */
int mbedtls_test_buffer_put(mbedtls_test_buffer *buf,
                            const unsigned char *input, size_t input_len)
{
    size_t overflow = 0;

    if ((buf == NULL) || (buf->buffer == NULL)) {
        return -1;
    }

    /* Reduce input_len to a number that fits in the buffer. */
    if ((buf->content_length + input_len) > buf->capacity) {
        input_len = buf->capacity - buf->content_length;
    }

    if (input == NULL) {
        return (input_len == 0) ? 0 : -1;
    }

    /* Check if the buffer has not come full circle and free space is not in
     * the middle */
    if (buf->start + buf->content_length < buf->capacity) {

        /* Calculate the number of bytes that need to be placed at lower memory
         * address */
        if (buf->start + buf->content_length + input_len
            > buf->capacity) {
            overflow = (buf->start + buf->content_length + input_len)
                       % buf->capacity;
        }

        memcpy(buf->buffer + buf->start + buf->content_length, input,
               input_len - overflow);
        memcpy(buf->buffer, input + input_len - overflow, overflow);

    } else {
        /* The buffer has come full circle and free space is in the middle */
        memcpy(buf->buffer + buf->start + buf->content_length - buf->capacity,
               input, input_len);
    }

    buf->content_length += input_len;
    return input_len;
}

/*
 * Gets \p output_len bytes from the ring buffer \p buf into the
 * \p output buffer. The output buffer can be NULL, in this case a part of the
 * ring buffer will be dropped, if the requested length is available.
 *
 * \p buf must have been initialized and set up by calling
 * `mbedtls_test_buffer_init()` and `mbedtls_test_buffer_setup()`.
 *
 * \retval  \p output_len, if the data is available.
 * \retval  0 <= value < \p output_len, if the data is not available.
 * \retval  -1, if \buf is NULL or it hasn't been set up.
 */
int mbedtls_test_buffer_get(mbedtls_test_buffer *buf,
                            unsigned char *output, size_t output_len)
{
    size_t overflow = 0;

    if ((buf == NULL) || (buf->buffer == NULL)) {
        return -1;
    }

    if (output == NULL && output_len == 0) {
        return 0;
    }

    if (buf->content_length < output_len) {
        output_len = buf->content_length;
    }

    /* Calculate the number of bytes that need to be drawn from lower memory
     * address */
    if (buf->start + output_len > buf->capacity) {
        overflow = (buf->start + output_len) % buf->capacity;
    }

    if (output != NULL) {
        memcpy(output, buf->buffer + buf->start, output_len - overflow);
        memcpy(output + output_len - overflow, buf->buffer, overflow);
    }

    buf->content_length -= output_len;
    buf->start = (buf->start + output_len) % buf->capacity;

    return output_len;
}

/*
 * Errors used in the message transport mock tests
 */
 #define MBEDTLS_TEST_ERROR_ARG_NULL -11
 #define MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED -44

/*
 * Context for a message metadata queue (fifo) that is on top of the ring buffer.
 */
typedef struct mbedtls_test_message_queue {
    size_t *messages;
    int pos;
    int num;
    int capacity;
} mbedtls_test_message_queue;

/*
 * Setup and free functions for the message metadata queue.
 *
 * \p capacity describes the number of message metadata chunks that can be held
 *    within the queue.
 *
 * \retval  0, if a metadata queue of a given length can be allocated.
 * \retval  MBEDTLS_ERR_SSL_ALLOC_FAILED, if allocation failed.
 */
int mbedtls_test_message_queue_setup(mbedtls_test_message_queue *queue,
                                     size_t capacity)
{
    queue->messages = (size_t *) mbedtls_calloc(capacity, sizeof(size_t));
    if (NULL == queue->messages) {
        return MBEDTLS_ERR_SSL_ALLOC_FAILED;
    }

    queue->capacity = capacity;
    queue->pos = 0;
    queue->num = 0;

    return 0;
}

void mbedtls_test_message_queue_free(mbedtls_test_message_queue *queue)
{
    if (queue == NULL) {
        return;
    }

    if (queue->messages != NULL) {
        mbedtls_free(queue->messages);
    }

    memset(queue, 0, sizeof(*queue));
}

/*
 * Push message length information onto the message metadata queue.
 * This will become the last element to leave it (fifo).
 *
 * \retval  MBEDTLS_TEST_ERROR_ARG_NULL, if the queue is null.
 * \retval  MBEDTLS_ERR_SSL_WANT_WRITE, if the queue is full.
 * \retval  \p len, if the push was successful.
 */
int mbedtls_test_message_queue_push_info(mbedtls_test_message_queue *queue,
                                         size_t len)
{
    int place;
    if (queue == NULL) {
        return MBEDTLS_TEST_ERROR_ARG_NULL;
    }

    if (queue->num >= queue->capacity) {
        return MBEDTLS_ERR_SSL_WANT_WRITE;
    }

    place = (queue->pos + queue->num) % queue->capacity;
    queue->messages[place] = len;
    queue->num++;
    return len;
}

/*
 * Pop information about the next message length from the queue. This will be
 * the oldest inserted message length(fifo). \p msg_len can be null, in which
 * case the data will be popped from the queue but not copied anywhere.
 *
 * \retval  MBEDTLS_TEST_ERROR_ARG_NULL, if the queue is null.
 * \retval  MBEDTLS_ERR_SSL_WANT_READ, if the queue is empty.
 * \retval  message length, if the pop was successful, up to the given
            \p buf_len.
 */
int mbedtls_test_message_queue_pop_info(mbedtls_test_message_queue *queue,
                                        size_t buf_len)
{
    size_t message_length;
    if (queue == NULL) {
        return MBEDTLS_TEST_ERROR_ARG_NULL;
    }
    if (queue->num == 0) {
        return MBEDTLS_ERR_SSL_WANT_READ;
    }

    message_length = queue->messages[queue->pos];
    queue->messages[queue->pos] = 0;
    queue->num--;
    queue->pos++;
    queue->pos %= queue->capacity;
    if (queue->pos < 0) {
        queue->pos += queue->capacity;
    }

    return (message_length > buf_len) ? buf_len : message_length;
}

/*
 * Take a peek on the info about the next message length from the queue.
 * This will be the oldest inserted message length(fifo).
 *
 * \retval  MBEDTLS_TEST_ERROR_ARG_NULL, if the queue is null.
 * \retval  MBEDTLS_ERR_SSL_WANT_READ, if the queue is empty.
 * \retval  0, if the peek was successful.
 * \retval  MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED, if the given buffer length is
 *          too small to fit the message. In this case the \p msg_len will be
 *          set to the full message length so that the
 *          caller knows what portion of the message can be dropped.
 */
int mbedtls_test_message_queue_peek_info(mbedtls_test_message_queue *queue,
                                         size_t buf_len, size_t *msg_len)
{
    if (queue == NULL || msg_len == NULL) {
        return MBEDTLS_TEST_ERROR_ARG_NULL;
    }
    if (queue->num == 0) {
        return MBEDTLS_ERR_SSL_WANT_READ;
    }

    *msg_len = queue->messages[queue->pos];
    return (*msg_len > buf_len) ? MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED : 0;
}
/*
 * Context for the I/O callbacks simulating network connection.
 */

#define MBEDTLS_MOCK_SOCKET_CONNECTED 1

typedef struct mbedtls_mock_socket {
    int status;
    mbedtls_test_buffer *input;
    mbedtls_test_buffer *output;
    struct mbedtls_mock_socket *peer;
} mbedtls_mock_socket;

/*
 * Setup and teardown functions for mock sockets.
 */
void mbedtls_mock_socket_init(mbedtls_mock_socket *socket)
{
    memset(socket, 0, sizeof(*socket));
}

/*
 * Closes the socket \p socket.
 *
 * \p socket must have been previously initialized by calling
 * mbedtls_mock_socket_init().
 *
 * This function frees all allocated resources and both sockets are aware of the
 * new connection state.
 *
 * That is, this function does not simulate half-open TCP connections and the
 * phenomenon that when closing a UDP connection the peer is not aware of the
 * connection having been closed.
 */
void mbedtls_mock_socket_close(mbedtls_mock_socket *socket)
{
    if (socket == NULL) {
        return;
    }

    if (socket->input != NULL) {
        mbedtls_test_buffer_free(socket->input);
        mbedtls_free(socket->input);
    }

    if (socket->output != NULL) {
        mbedtls_test_buffer_free(socket->output);
        mbedtls_free(socket->output);
    }

    if (socket->peer != NULL) {
        memset(socket->peer, 0, sizeof(*socket->peer));
    }

    memset(socket, 0, sizeof(*socket));
}

/*
 * Establishes a connection between \p peer1 and \p peer2.
 *
 * \p peer1 and \p peer2 must have been previously initialized by calling
 * mbedtls_mock_socket_init().
 *
 * The capacities of the internal buffers are set to \p bufsize. Setting this to
 * the correct value allows for simulation of MTU, sanity testing the mock
 * implementation and mocking TCP connections with lower memory cost.
 */
int mbedtls_mock_socket_connect(mbedtls_mock_socket *peer1,
                                mbedtls_mock_socket *peer2,
                                size_t bufsize)
{
    int ret = -1;

    peer1->output =
        (mbedtls_test_buffer *) mbedtls_calloc(1, sizeof(mbedtls_test_buffer));
    if (peer1->output == NULL) {
        ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
        goto exit;
    }
    mbedtls_test_buffer_init(peer1->output);
    if (0 != (ret = mbedtls_test_buffer_setup(peer1->output, bufsize))) {
        goto exit;
    }

    peer2->output =
        (mbedtls_test_buffer *) mbedtls_calloc(1, sizeof(mbedtls_test_buffer));
    if (peer2->output == NULL) {
        ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
        goto exit;
    }
    mbedtls_test_buffer_init(peer2->output);
    if (0 != (ret = mbedtls_test_buffer_setup(peer2->output, bufsize))) {
        goto exit;
    }

    peer1->peer = peer2;
    peer2->peer = peer1;
    peer1->input = peer2->output;
    peer2->input = peer1->output;

    peer1->status = peer2->status = MBEDTLS_MOCK_SOCKET_CONNECTED;
    ret = 0;

exit:

    if (ret != 0) {
        mbedtls_mock_socket_close(peer1);
        mbedtls_mock_socket_close(peer2);
    }

    return ret;
}

/*
 * Callbacks for simulating blocking I/O over connection-oriented transport.
 */

int mbedtls_mock_tcp_send_b(void *ctx, const unsigned char *buf, size_t len)
{
    mbedtls_mock_socket *socket = (mbedtls_mock_socket *) ctx;

    if (socket == NULL || socket->status != MBEDTLS_MOCK_SOCKET_CONNECTED) {
        return -1;
    }

    return mbedtls_test_buffer_put(socket->output, buf, len);
}

int mbedtls_mock_tcp_recv_b(void *ctx, unsigned char *buf, size_t len)
{
    mbedtls_mock_socket *socket = (mbedtls_mock_socket *) ctx;

    if (socket == NULL || socket->status != MBEDTLS_MOCK_SOCKET_CONNECTED) {
        return -1;
    }

    return mbedtls_test_buffer_get(socket->input, buf, len);
}

/*
 * Callbacks for simulating non-blocking I/O over connection-oriented transport.
 */

int mbedtls_mock_tcp_send_nb(void *ctx, const unsigned char *buf, size_t len)
{
    mbedtls_mock_socket *socket = (mbedtls_mock_socket *) ctx;

    if (socket == NULL || socket->status != MBEDTLS_MOCK_SOCKET_CONNECTED) {
        return -1;
    }

    if (socket->output->capacity == socket->output->content_length) {
        return MBEDTLS_ERR_SSL_WANT_WRITE;
    }

    return mbedtls_test_buffer_put(socket->output, buf, len);
}

int mbedtls_mock_tcp_recv_nb(void *ctx, unsigned char *buf, size_t len)
{
    mbedtls_mock_socket *socket = (mbedtls_mock_socket *) ctx;

    if (socket == NULL || socket->status != MBEDTLS_MOCK_SOCKET_CONNECTED) {
        return -1;
    }

    if (socket->input->content_length == 0) {
        return MBEDTLS_ERR_SSL_WANT_READ;
    }

    return mbedtls_test_buffer_get(socket->input, buf, len);
}

/* Errors used in the message socket mocks */

#define MBEDTLS_TEST_ERROR_CONTEXT_ERROR -55
#define MBEDTLS_TEST_ERROR_SEND_FAILED -66
#define MBEDTLS_TEST_ERROR_RECV_FAILED -77

/*
 * Structure used as an addon, or a wrapper, around the mocked sockets.
 * Contains an input queue, to which the other socket pushes metadata,
 * and an output queue, to which this one pushes metadata. This context is
 * considered as an owner of the input queue only, which is initialized and
 * freed in the respective setup and free calls.
 */
typedef struct mbedtls_test_message_socket_context {
    mbedtls_test_message_queue *queue_input;
    mbedtls_test_message_queue *queue_output;
    mbedtls_mock_socket *socket;
} mbedtls_test_message_socket_context;

void mbedtls_message_socket_init(mbedtls_test_message_socket_context *ctx)
{
    ctx->queue_input = NULL;
    ctx->queue_output = NULL;
    ctx->socket = NULL;
}

/*
 * Setup a given message socket context including initialization of
 * input/output queues to a chosen capacity of messages. Also set the
 * corresponding mock socket.
 *
 * \retval  0, if everything succeeds.
 * \retval  MBEDTLS_ERR_SSL_ALLOC_FAILED, if allocation of a message
 *          queue failed.
 */
int mbedtls_message_socket_setup(mbedtls_test_message_queue *queue_input,
                                 mbedtls_test_message_queue *queue_output,
                                 size_t queue_capacity,
                                 mbedtls_mock_socket *socket,
                                 mbedtls_test_message_socket_context *ctx)
{
    int ret = mbedtls_test_message_queue_setup(queue_input, queue_capacity);
    if (ret != 0) {
        return ret;
    }
    ctx->queue_input = queue_input;
    ctx->queue_output = queue_output;
    ctx->socket = socket;
    mbedtls_mock_socket_init(socket);

    return 0;
}

/*
 * Close a given message socket context, along with the socket itself. Free the
 * memory allocated by the input queue.
 */
void mbedtls_message_socket_close(mbedtls_test_message_socket_context *ctx)
{
    if (ctx == NULL) {
        return;
    }

    mbedtls_test_message_queue_free(ctx->queue_input);
    mbedtls_mock_socket_close(ctx->socket);
    memset(ctx, 0, sizeof(*ctx));
}

/*
 * Send one message through a given message socket context.
 *
 * \retval  \p len, if everything succeeds.
 * \retval  MBEDTLS_TEST_ERROR_CONTEXT_ERROR, if any of the needed context
 *          elements or the context itself is null.
 * \retval  MBEDTLS_TEST_ERROR_SEND_FAILED if mbedtls_mock_tcp_send_b failed.
 * \retval  MBEDTLS_ERR_SSL_WANT_WRITE, if the output queue is full.
 *
 * This function will also return any error from
 * mbedtls_test_message_queue_push_info.
 */
int mbedtls_mock_tcp_send_msg(void *ctx, const unsigned char *buf, size_t len)
{
    mbedtls_test_message_queue *queue;
    mbedtls_mock_socket *socket;
    mbedtls_test_message_socket_context *context = (mbedtls_test_message_socket_context *) ctx;

    if (context == NULL || context->socket == NULL
        || context->queue_output == NULL) {
        return MBEDTLS_TEST_ERROR_CONTEXT_ERROR;
    }

    queue = context->queue_output;
    socket = context->socket;

    if (queue->num >= queue->capacity) {
        return MBEDTLS_ERR_SSL_WANT_WRITE;
    }

    if (mbedtls_mock_tcp_send_b(socket, buf, len) != (int) len) {
        return MBEDTLS_TEST_ERROR_SEND_FAILED;
    }

    return mbedtls_test_message_queue_push_info(queue, len);
}

/*
 * Receive one message from a given message socket context and return message
 * length or an error.
 *
 * \retval  message length, if everything succeeds.
 * \retval  MBEDTLS_TEST_ERROR_CONTEXT_ERROR, if any of the needed context
 *          elements or the context itself is null.
 * \retval  MBEDTLS_TEST_ERROR_RECV_FAILED if mbedtls_mock_tcp_recv_b failed.
 *
 * This function will also return any error other than
 * MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED from mbedtls_test_message_queue_peek_info.
 */
int mbedtls_mock_tcp_recv_msg(void *ctx, unsigned char *buf, size_t buf_len)
{
    mbedtls_test_message_queue *queue;
    mbedtls_mock_socket *socket;
    mbedtls_test_message_socket_context *context = (mbedtls_test_message_socket_context *) ctx;
    size_t drop_len = 0;
    size_t msg_len;
    int ret;

    if (context == NULL || context->socket == NULL
        || context->queue_input == NULL) {
        return MBEDTLS_TEST_ERROR_CONTEXT_ERROR;
    }

    queue = context->queue_input;
    socket = context->socket;

    /* Peek first, so that in case of a socket error the data remains in
     * the queue. */
    ret = mbedtls_test_message_queue_peek_info(queue, buf_len, &msg_len);
    if (ret == MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED) {
        /* Calculate how much to drop */
        drop_len = msg_len - buf_len;

        /* Set the requested message len to be buffer length */
        msg_len = buf_len;
    } else if (ret != 0) {
        return ret;
    }

    if (mbedtls_mock_tcp_recv_b(socket, buf, msg_len) != (int) msg_len) {
        return MBEDTLS_TEST_ERROR_RECV_FAILED;
    }

    if (ret == MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED) {
        /* Drop the remaining part of the message */
        if (mbedtls_mock_tcp_recv_b(socket, NULL, drop_len) != (int) drop_len) {
            /* Inconsistent state - part of the message was read,
             * and a part couldn't. Not much we can do here, but it should not
             * happen in test environment, unless forced manually. */
        }
    }
    mbedtls_test_message_queue_pop_info(queue, buf_len);

    return msg_len;
}

#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) && \
    defined(MBEDTLS_ENTROPY_C) && \
    defined(MBEDTLS_CTR_DRBG_C)

/*
 * Structure with endpoint's certificates for SSL communication tests.
 */
typedef struct mbedtls_endpoint_certificate {
    mbedtls_x509_crt *ca_cert;
    mbedtls_x509_crt *cert;
    mbedtls_pk_context *pkey;
} mbedtls_endpoint_certificate;

/*
 * Endpoint structure for SSL communication tests.
 */
typedef struct mbedtls_endpoint {
    const char *name;
    mbedtls_ssl_context ssl;
    mbedtls_ssl_config conf;
    mbedtls_ctr_drbg_context ctr_drbg;
    mbedtls_entropy_context entropy;
    mbedtls_mock_socket socket;
    mbedtls_endpoint_certificate cert;
} mbedtls_endpoint;

/*
 * Deinitializes certificates from endpoint represented by \p ep.
 */
void mbedtls_endpoint_certificate_free(mbedtls_endpoint *ep)
{
    mbedtls_endpoint_certificate *cert = &(ep->cert);
    if (cert != NULL) {
        if (cert->ca_cert != NULL) {
            mbedtls_x509_crt_free(cert->ca_cert);
            mbedtls_free(cert->ca_cert);
            cert->ca_cert = NULL;
        }
        if (cert->cert != NULL) {
            mbedtls_x509_crt_free(cert->cert);
            mbedtls_free(cert->cert);
            cert->cert = NULL;
        }
        if (cert->pkey != NULL) {
#if defined(MBEDTLS_USE_PSA_CRYPTO)
            if (mbedtls_pk_get_type(cert->pkey) == MBEDTLS_PK_OPAQUE) {
                mbedtls_svc_key_id_t *key_slot = cert->pkey->pk_ctx;
                psa_destroy_key(*key_slot);
            }
#endif
            mbedtls_pk_free(cert->pkey);
            mbedtls_free(cert->pkey);
            cert->pkey = NULL;
        }
    }
}

/*
 * Initializes \p ep_cert structure and assigns it to endpoint
 * represented by \p ep.
 *
 * \retval  0 on success, otherwise error code.
 */
int mbedtls_endpoint_certificate_init(mbedtls_endpoint *ep, int pk_alg)
{
    int i = 0;
    int ret = -1;
    mbedtls_endpoint_certificate *cert = NULL;

    if (ep == NULL) {
        return MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
    }

    cert = &(ep->cert);
    ASSERT_ALLOC(cert->ca_cert, 1);
    ASSERT_ALLOC(cert->cert, 1);
    ASSERT_ALLOC(cert->pkey, 1);

    mbedtls_x509_crt_init(cert->ca_cert);
    mbedtls_x509_crt_init(cert->cert);
    mbedtls_pk_init(cert->pkey);

    /* Load the trusted CA */

    for (i = 0; mbedtls_test_cas_der[i] != NULL; i++) {
        ret = mbedtls_x509_crt_parse_der(cert->ca_cert,
                                         (const unsigned char *) mbedtls_test_cas_der[i],
                                         mbedtls_test_cas_der_len[i]);
        TEST_ASSERT(ret == 0);
    }

    /* Load own certificate and private key */

    if (ep->conf.endpoint == MBEDTLS_SSL_IS_SERVER) {
        if (pk_alg == MBEDTLS_PK_RSA) {
            ret = mbedtls_x509_crt_parse(cert->cert,
                                         (const unsigned char *) mbedtls_test_srv_crt_rsa_sha256_der,
                                         mbedtls_test_srv_crt_rsa_sha256_der_len);
            TEST_ASSERT(ret == 0);

            ret = mbedtls_pk_parse_key(cert->pkey,
                                       (const unsigned char *) mbedtls_test_srv_key_rsa_der,
                                       mbedtls_test_srv_key_rsa_der_len, NULL, 0);
            TEST_ASSERT(ret == 0);
        } else {
            ret = mbedtls_x509_crt_parse(cert->cert,
                                         (const unsigned char *) mbedtls_test_srv_crt_ec_der,
                                         mbedtls_test_srv_crt_ec_der_len);
            TEST_ASSERT(ret == 0);

            ret = mbedtls_pk_parse_key(cert->pkey,
                                       (const unsigned char *) mbedtls_test_srv_key_ec_der,
                                       mbedtls_test_srv_key_ec_der_len, NULL, 0);
            TEST_ASSERT(ret == 0);
        }
    } else {
        if (pk_alg == MBEDTLS_PK_RSA) {
            ret = mbedtls_x509_crt_parse(cert->cert,
                                         (const unsigned char *) mbedtls_test_cli_crt_rsa_der,
                                         mbedtls_test_cli_crt_rsa_der_len);
            TEST_ASSERT(ret == 0);

            ret = mbedtls_pk_parse_key(cert->pkey,
                                       (const unsigned char *) mbedtls_test_cli_key_rsa_der,
                                       mbedtls_test_cli_key_rsa_der_len, NULL, 0);
            TEST_ASSERT(ret == 0);
        } else {
            ret = mbedtls_x509_crt_parse(cert->cert,
                                         (const unsigned char *) mbedtls_test_cli_crt_ec_der,
                                         mbedtls_test_cli_crt_ec_len);
            TEST_ASSERT(ret == 0);

            ret = mbedtls_pk_parse_key(cert->pkey,
                                       (const unsigned char *) mbedtls_test_cli_key_ec_der,
                                       mbedtls_test_cli_key_ec_der_len, NULL, 0);
            TEST_ASSERT(ret == 0);
        }
    }

    mbedtls_ssl_conf_ca_chain(&(ep->conf), cert->ca_cert, NULL);

    ret = mbedtls_ssl_conf_own_cert(&(ep->conf), cert->cert,
                                    cert->pkey);
    TEST_ASSERT(ret == 0);

exit:
    if (ret != 0) {
        mbedtls_endpoint_certificate_free(ep);
    }

    return ret;
}

/*
 * Initializes \p ep structure. It is important to call `mbedtls_endpoint_free()`
 * after calling this function even if it fails.
 *
 * \p endpoint_type must be set as MBEDTLS_SSL_IS_SERVER or
 * MBEDTLS_SSL_IS_CLIENT.
 * \p pk_alg the algorithm to use, currently only MBEDTLS_PK_RSA and
 * MBEDTLS_PK_ECDSA are supported.
 * \p dtls_context - in case of DTLS - this is the context handling metadata.
 * \p input_queue - used only in case of DTLS.
 * \p output_queue - used only in case of DTLS.
 *
 * \retval  0 on success, otherwise error code.
 */
int mbedtls_endpoint_init(mbedtls_endpoint *ep, int endpoint_type, int pk_alg,
                          mbedtls_test_message_socket_context *dtls_context,
                          mbedtls_test_message_queue *input_queue,
                          mbedtls_test_message_queue *output_queue,
                          const mbedtls_ecp_group_id *curves)
{
    int ret = -1;

    if (dtls_context != NULL && (input_queue == NULL || output_queue == NULL)) {
        return MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
    }

    if (ep == NULL) {
        return MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
    }

    memset(ep, 0, sizeof(*ep));

    ep->name = (endpoint_type == MBEDTLS_SSL_IS_SERVER) ? "Server" : "Client";

    mbedtls_ssl_init(&(ep->ssl));
    mbedtls_ssl_config_init(&(ep->conf));
    mbedtls_ctr_drbg_init(&(ep->ctr_drbg));
    mbedtls_ssl_conf_rng(&(ep->conf),
                         mbedtls_ctr_drbg_random,
                         &(ep->ctr_drbg));
    mbedtls_entropy_init(&(ep->entropy));
    if (dtls_context != NULL) {
        TEST_ASSERT(mbedtls_message_socket_setup(input_queue, output_queue,
                                                 100, &(ep->socket),
                                                 dtls_context) == 0);
    } else {
        mbedtls_mock_socket_init(&(ep->socket));
    }

    ret = mbedtls_ctr_drbg_seed(&(ep->ctr_drbg), mbedtls_entropy_func,
                                &(ep->entropy), (const unsigned char *) (ep->name),
                                strlen(ep->name));
    TEST_ASSERT(ret == 0);

    /* Non-blocking callbacks without timeout */
    if (dtls_context != NULL) {
        mbedtls_ssl_set_bio(&(ep->ssl), dtls_context,
                            mbedtls_mock_tcp_send_msg,
                            mbedtls_mock_tcp_recv_msg,
                            NULL);
    } else {
        mbedtls_ssl_set_bio(&(ep->ssl), &(ep->socket),
                            mbedtls_mock_tcp_send_nb,
                            mbedtls_mock_tcp_recv_nb,
                            NULL);
    }

    ret = mbedtls_ssl_config_defaults(&(ep->conf), endpoint_type,
                                      (dtls_context != NULL) ?
                                      MBEDTLS_SSL_TRANSPORT_DATAGRAM :
                                      MBEDTLS_SSL_TRANSPORT_STREAM,
                                      MBEDTLS_SSL_PRESET_DEFAULT);
    TEST_ASSERT(ret == 0);

#if defined(MBEDTLS_ECP_C)
    if (curves != NULL) {
        mbedtls_ssl_conf_curves(&(ep->conf), curves);
    }
#else
    (void) curves;
#endif

    ret = mbedtls_ssl_setup(&(ep->ssl), &(ep->conf));
    TEST_ASSERT(ret == 0);

#if defined(MBEDTLS_SSL_PROTO_DTLS) && defined(MBEDTLS_SSL_SRV_C)
    if (endpoint_type == MBEDTLS_SSL_IS_SERVER && dtls_context != NULL) {
        mbedtls_ssl_conf_dtls_cookies(&(ep->conf), NULL, NULL, NULL);
    }
#endif

    ret = mbedtls_endpoint_certificate_init(ep, pk_alg);
    TEST_ASSERT(ret == 0);

exit:
    return ret;
}

/*
 * Deinitializes endpoint represented by \p ep.
 */
void mbedtls_endpoint_free(mbedtls_endpoint *ep,
                           mbedtls_test_message_socket_context *context)
{
    mbedtls_endpoint_certificate_free(ep);

    mbedtls_ssl_free(&(ep->ssl));
    mbedtls_ssl_config_free(&(ep->conf));
    mbedtls_ctr_drbg_free(&(ep->ctr_drbg));
    mbedtls_entropy_free(&(ep->entropy));

    if (context != NULL) {
        mbedtls_message_socket_close(context);
    } else {
        mbedtls_mock_socket_close(&(ep->socket));
    }
}

/*
 * This function moves ssl handshake from \p ssl to prescribed \p state.
 * /p second_ssl is used as second endpoint and their sockets have to be
 * connected before calling this function.
 *
 * \retval  0 on success, otherwise error code.
 */
int mbedtls_move_handshake_to_state(mbedtls_ssl_context *ssl,
                                    mbedtls_ssl_context *second_ssl,
                                    int state)
{
    enum { BUFFSIZE = 1024 };
    int max_steps = 1000;
    int ret = 0;

    if (ssl == NULL || second_ssl == NULL) {
        return MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
    }

    /* Perform communication via connected sockets */
    while ((ssl->state != state) && (--max_steps >= 0)) {
        /* If /p second_ssl ends the handshake procedure before /p ssl then
         * there is no need to call the next step */
        if (second_ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER) {
            ret = mbedtls_ssl_handshake_step(second_ssl);
            if (ret != 0 && ret != MBEDTLS_ERR_SSL_WANT_READ &&
                ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
                return ret;
            }
        }

        /* We only care about the \p ssl state and returns, so we call it last,
         * to leave the iteration as soon as the state is as expected. */
        ret = mbedtls_ssl_handshake_step(ssl);
        if (ret != 0 && ret != MBEDTLS_ERR_SSL_WANT_READ &&
            ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
            return ret;
        }
    }

    return (max_steps >= 0) ? ret : -1;
}

#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */

/*
 * Write application data. Increase write counter if necessary.
 */
int mbedtls_ssl_write_fragment(mbedtls_ssl_context *ssl, unsigned char *buf,
                               int buf_len, int *written,
                               const int expected_fragments)
{
    int ret = mbedtls_ssl_write(ssl, buf + *written, buf_len - *written);
    if (ret > 0) {
        *written += ret;
    }

    if (expected_fragments == 0) {
        /* Used for DTLS and the message size larger than MFL. In that case
         * the message can not be fragmented and the library should return
         * MBEDTLS_ERR_SSL_BAD_INPUT_DATA error. This error must be returned
         * to prevent a dead loop inside mbedtls_exchange_data(). */
        return ret;
    } else if (expected_fragments == 1) {
        /* Used for TLS/DTLS and the message size lower than MFL */
        TEST_ASSERT(ret == buf_len ||
                    ret == MBEDTLS_ERR_SSL_WANT_READ ||
                    ret == MBEDTLS_ERR_SSL_WANT_WRITE);
    } else {
        /* Used for TLS and the message size larger than MFL */
        TEST_ASSERT(expected_fragments > 1);
        TEST_ASSERT((ret >= 0 && ret <= buf_len) ||
                    ret == MBEDTLS_ERR_SSL_WANT_READ ||
                    ret == MBEDTLS_ERR_SSL_WANT_WRITE);
    }

    return 0;

exit:
    /* Some of the tests failed */
    return -1;
}

/*
 * Read application data and increase read counter and fragments counter if necessary.
 */
int mbedtls_ssl_read_fragment(mbedtls_ssl_context *ssl, unsigned char *buf,
                              int buf_len, int *read,
                              int *fragments, const int expected_fragments)
{
    int ret = mbedtls_ssl_read(ssl, buf + *read, buf_len - *read);
    if (ret > 0) {
        (*fragments)++;
        *read += ret;
    }

    if (expected_fragments == 0) {
        TEST_ASSERT(ret == 0);
    } else if (expected_fragments == 1) {
        TEST_ASSERT(ret == buf_len ||
                    ret == MBEDTLS_ERR_SSL_WANT_READ ||
                    ret == MBEDTLS_ERR_SSL_WANT_WRITE);
    } else {
        TEST_ASSERT(expected_fragments > 1);
        TEST_ASSERT((ret >= 0 && ret <= buf_len) ||
                    ret == MBEDTLS_ERR_SSL_WANT_READ ||
                    ret == MBEDTLS_ERR_SSL_WANT_WRITE);
    }

    return 0;

exit:
    /* Some of the tests failed */
    return -1;
}

/*
 * Helper function setting up inverse record transformations
 * using given cipher, hash, EtM mode, authentication tag length,
 * and version.
 */

#define CHK(x)                                \
    do                                          \
    {                                           \
        if (!(x))                            \
        {                                       \
            ret = -1;                           \
            goto cleanup;                       \
        }                                       \
    } while (0)

void set_ciphersuite(mbedtls_ssl_config *conf, const char *cipher,
                     int *forced_ciphersuite)
{
    const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
    forced_ciphersuite[0] = mbedtls_ssl_get_ciphersuite_id(cipher);
    forced_ciphersuite[1] = 0;

    ciphersuite_info =
        mbedtls_ssl_ciphersuite_from_id(forced_ciphersuite[0]);

    TEST_ASSERT(ciphersuite_info != NULL);
    TEST_ASSERT(ciphersuite_info->min_minor_ver <= conf->max_minor_ver);
    TEST_ASSERT(ciphersuite_info->max_minor_ver >= conf->min_minor_ver);

    if (conf->max_minor_ver > ciphersuite_info->max_minor_ver) {
        conf->max_minor_ver = ciphersuite_info->max_minor_ver;
    }
    if (conf->min_minor_ver < ciphersuite_info->min_minor_ver) {
        conf->min_minor_ver = ciphersuite_info->min_minor_ver;
    }

    mbedtls_ssl_conf_ciphersuites(conf, forced_ciphersuite);

exit:
    return;
}

int psk_dummy_callback(void *p_info, mbedtls_ssl_context *ssl,
                       const unsigned char *name, size_t name_len)
{
    (void) p_info;
    (void) ssl;
    (void) name;
    (void) name_len;

    return 0;
}

#if MBEDTLS_SSL_CID_OUT_LEN_MAX > MBEDTLS_SSL_CID_IN_LEN_MAX
#define SSL_CID_LEN_MIN MBEDTLS_SSL_CID_IN_LEN_MAX
#else
#define SSL_CID_LEN_MIN MBEDTLS_SSL_CID_OUT_LEN_MAX
#endif

static int build_transforms(mbedtls_ssl_transform *t_in,
                            mbedtls_ssl_transform *t_out,
                            int cipher_type, int hash_id,
                            int etm, int tag_mode, int ver,
                            size_t cid0_len,
                            size_t cid1_len)
{
    mbedtls_cipher_info_t const *cipher_info;
    int ret = 0;

    size_t keylen, maclen, ivlen;
    unsigned char *key0 = NULL, *key1 = NULL;
    unsigned char *md0 = NULL, *md1 = NULL;
    unsigned char iv_enc[16], iv_dec[16];

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    unsigned char cid0[SSL_CID_LEN_MIN];
    unsigned char cid1[SSL_CID_LEN_MIN];

    mbedtls_test_rnd_std_rand(NULL, cid0, sizeof(cid0));
    mbedtls_test_rnd_std_rand(NULL, cid1, sizeof(cid1));
#else
    ((void) cid0_len);
    ((void) cid1_len);
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

    maclen = 0;

    /* Pick cipher */
    cipher_info = mbedtls_cipher_info_from_type(cipher_type);
    CHK(cipher_info != NULL);
    CHK(cipher_info->iv_size <= 16);
    CHK(cipher_info->key_bitlen % 8 == 0);

    /* Pick keys */
    keylen = cipher_info->key_bitlen / 8;
    /* Allocate `keylen + 1` bytes to ensure that we get
     * a non-NULL pointers from `mbedtls_calloc` even if
     * `keylen == 0` in the case of the NULL cipher. */
    CHK((key0 = mbedtls_calloc(1, keylen + 1)) != NULL);
    CHK((key1 = mbedtls_calloc(1, keylen + 1)) != NULL);
    memset(key0, 0x1, keylen);
    memset(key1, 0x2, keylen);

    /* Setup cipher contexts */
    CHK(mbedtls_cipher_setup(&t_in->cipher_ctx_enc,  cipher_info) == 0);
    CHK(mbedtls_cipher_setup(&t_in->cipher_ctx_dec,  cipher_info) == 0);
    CHK(mbedtls_cipher_setup(&t_out->cipher_ctx_enc, cipher_info) == 0);
    CHK(mbedtls_cipher_setup(&t_out->cipher_ctx_dec, cipher_info) == 0);

#if defined(MBEDTLS_CIPHER_MODE_CBC)
    if (cipher_info->mode == MBEDTLS_MODE_CBC) {
        CHK(mbedtls_cipher_set_padding_mode(&t_in->cipher_ctx_enc,
                                            MBEDTLS_PADDING_NONE) == 0);
        CHK(mbedtls_cipher_set_padding_mode(&t_in->cipher_ctx_dec,
                                            MBEDTLS_PADDING_NONE) == 0);
        CHK(mbedtls_cipher_set_padding_mode(&t_out->cipher_ctx_enc,
                                            MBEDTLS_PADDING_NONE) == 0);
        CHK(mbedtls_cipher_set_padding_mode(&t_out->cipher_ctx_dec,
                                            MBEDTLS_PADDING_NONE) == 0);
    }
#endif /* MBEDTLS_CIPHER_MODE_CBC */

    CHK(mbedtls_cipher_setkey(&t_in->cipher_ctx_enc, key0,
                              keylen << 3, MBEDTLS_ENCRYPT) == 0);
    CHK(mbedtls_cipher_setkey(&t_in->cipher_ctx_dec, key1,
                              keylen << 3, MBEDTLS_DECRYPT) == 0);
    CHK(mbedtls_cipher_setkey(&t_out->cipher_ctx_enc, key1,
                              keylen << 3, MBEDTLS_ENCRYPT) == 0);
    CHK(mbedtls_cipher_setkey(&t_out->cipher_ctx_dec, key0,
                              keylen << 3, MBEDTLS_DECRYPT) == 0);

    /* Setup MAC contexts */
#if defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
    if (cipher_info->mode == MBEDTLS_MODE_CBC ||
        cipher_info->mode == MBEDTLS_MODE_STREAM) {
        mbedtls_md_info_t const *md_info;

        /* Pick hash */
        md_info = mbedtls_md_info_from_type(hash_id);
        CHK(md_info != NULL);

        /* Pick hash keys */
        maclen = mbedtls_md_get_size(md_info);
        CHK((md0 = mbedtls_calloc(1, maclen)) != NULL);
        CHK((md1 = mbedtls_calloc(1, maclen)) != NULL);
        memset(md0, 0x5, maclen);
        memset(md1, 0x6, maclen);

        CHK(mbedtls_md_setup(&t_out->md_ctx_enc, md_info, 1) == 0);
        CHK(mbedtls_md_setup(&t_out->md_ctx_dec, md_info, 1) == 0);
        CHK(mbedtls_md_setup(&t_in->md_ctx_enc,  md_info, 1) == 0);
        CHK(mbedtls_md_setup(&t_in->md_ctx_dec,  md_info, 1) == 0);

        if (ver > MBEDTLS_SSL_MINOR_VERSION_0) {
            CHK(mbedtls_md_hmac_starts(&t_in->md_ctx_enc,
                                       md0, maclen) == 0);
            CHK(mbedtls_md_hmac_starts(&t_in->md_ctx_dec,
                                       md1, maclen) == 0);
            CHK(mbedtls_md_hmac_starts(&t_out->md_ctx_enc,
                                       md1, maclen) == 0);
            CHK(mbedtls_md_hmac_starts(&t_out->md_ctx_dec,
                                       md0, maclen) == 0);
        }
#if defined(MBEDTLS_SSL_PROTO_SSL3)
        else {
            memcpy(&t_in->mac_enc, md0, maclen);
            memcpy(&t_in->mac_dec, md1, maclen);
            memcpy(&t_out->mac_enc, md1, maclen);
            memcpy(&t_out->mac_dec, md0, maclen);
        }
#endif
    }
#else
    ((void) hash_id);
#endif /* MBEDTLS_SSL_SOME_MODES_USE_MAC */


    /* Pick IV's (regardless of whether they
     * are being used by the transform). */
    ivlen = cipher_info->iv_size;
    memset(iv_enc, 0x3, sizeof(iv_enc));
    memset(iv_dec, 0x4, sizeof(iv_dec));

    /*
     * Setup transforms
     */

#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) && \
    defined(MBEDTLS_SSL_SOME_MODES_USE_MAC)
    t_out->encrypt_then_mac = etm;
    t_in->encrypt_then_mac = etm;
#else
    ((void) etm);
#endif

    t_out->minor_ver = ver;
    t_in->minor_ver = ver;
    t_out->ivlen = ivlen;
    t_in->ivlen = ivlen;

    switch (cipher_info->mode) {
        case MBEDTLS_MODE_GCM:
        case MBEDTLS_MODE_CCM:
#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
            if (ver == MBEDTLS_SSL_MINOR_VERSION_4) {
                t_out->fixed_ivlen = 12;
                t_in->fixed_ivlen  = 12;
            } else
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
            {
                t_out->fixed_ivlen = 4;
                t_in->fixed_ivlen = 4;
            }
            t_out->maclen = 0;
            t_in->maclen = 0;
            switch (tag_mode) {
                case 0: /* Full tag */
                    t_out->taglen = 16;
                    t_in->taglen = 16;
                    break;
                case 1: /* Partial tag */
                    t_out->taglen = 8;
                    t_in->taglen = 8;
                    break;
                default:
                    ret = 1;
                    goto cleanup;
            }
            break;

        case MBEDTLS_MODE_CHACHAPOLY:
            t_out->fixed_ivlen = 12;
            t_in->fixed_ivlen = 12;
            t_out->maclen = 0;
            t_in->maclen = 0;
            switch (tag_mode) {
                case 0: /* Full tag */
                    t_out->taglen = 16;
                    t_in->taglen = 16;
                    break;
                case 1: /* Partial tag */
                    t_out->taglen = 8;
                    t_in->taglen = 8;
                    break;
                default:
                    ret = 1;
                    goto cleanup;
            }
            break;

        case MBEDTLS_MODE_STREAM:
        case MBEDTLS_MODE_CBC:
            t_out->fixed_ivlen = 0; /* redundant, must be 0 */
            t_in->fixed_ivlen = 0;  /* redundant, must be 0 */
            t_out->taglen = 0;
            t_in->taglen = 0;
            switch (tag_mode) {
                case 0: /* Full tag */
                    t_out->maclen = maclen;
                    t_in->maclen = maclen;
                    break;
                case 1: /* Partial tag */
                    t_out->maclen = 10;
                    t_in->maclen = 10;
                    break;
                default:
                    ret = 1;
                    goto cleanup;
            }
            break;
        default:
            ret = 1;
            goto cleanup;
            break;
    }

    /* Setup IV's */

    memcpy(&t_in->iv_dec, iv_dec, sizeof(iv_dec));
    memcpy(&t_in->iv_enc, iv_enc, sizeof(iv_enc));
    memcpy(&t_out->iv_dec, iv_enc, sizeof(iv_enc));
    memcpy(&t_out->iv_enc, iv_dec, sizeof(iv_dec));

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    /* Add CID */
    memcpy(&t_in->in_cid,  cid0, cid0_len);
    memcpy(&t_in->out_cid, cid1, cid1_len);
    t_in->in_cid_len = cid0_len;
    t_in->out_cid_len = cid1_len;
    memcpy(&t_out->in_cid,  cid1, cid1_len);
    memcpy(&t_out->out_cid, cid0, cid0_len);
    t_out->in_cid_len = cid1_len;
    t_out->out_cid_len = cid0_len;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

cleanup:

    mbedtls_free(key0);
    mbedtls_free(key1);

    mbedtls_free(md0);
    mbedtls_free(md1);

    return ret;
}

/*
 * Populate a session structure for serialization tests.
 * Choose dummy values, mostly non-0 to distinguish from the init default.
 */
static int ssl_populate_session(mbedtls_ssl_session *session,
                                int ticket_len,
                                const char *crt_file)
{
#if defined(MBEDTLS_HAVE_TIME)
    session->start = mbedtls_time(NULL) - 42;
#endif
    session->ciphersuite = 0xabcd;
    session->compression = 1;
    session->id_len = sizeof(session->id);
    memset(session->id, 66, session->id_len);
    memset(session->master, 17, sizeof(session->master));

#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) && defined(MBEDTLS_FS_IO)
    if (strlen(crt_file) != 0) {
        mbedtls_x509_crt tmp_crt;
        int ret;

        mbedtls_x509_crt_init(&tmp_crt);
        ret = mbedtls_x509_crt_parse_file(&tmp_crt, crt_file);
        if (ret != 0) {
            return ret;
        }

#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
        /* Move temporary CRT. */
        session->peer_cert = mbedtls_calloc(1, sizeof(*session->peer_cert));
        if (session->peer_cert == NULL) {
            return -1;
        }
        *session->peer_cert = tmp_crt;
        memset(&tmp_crt, 0, sizeof(tmp_crt));
#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
        /* Calculate digest of temporary CRT. */
        session->peer_cert_digest =
            mbedtls_calloc(1, MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN);
        if (session->peer_cert_digest == NULL) {
            return -1;
        }
        ret = mbedtls_md(mbedtls_md_info_from_type(
                             MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE),
                         tmp_crt.raw.p, tmp_crt.raw.len,
                         session->peer_cert_digest);
        if (ret != 0) {
            return ret;
        }
        session->peer_cert_digest_type =
            MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE;
        session->peer_cert_digest_len =
            MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN;
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */

        mbedtls_x509_crt_free(&tmp_crt);
    }
#else /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && MBEDTLS_FS_IO */
    (void) crt_file;
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && MBEDTLS_FS_IO */
    session->verify_result = 0xdeadbeef;

#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
    if (ticket_len != 0) {
        session->ticket = mbedtls_calloc(1, ticket_len);
        if (session->ticket == NULL) {
            return -1;
        }
        memset(session->ticket, 33, ticket_len);
    }
    session->ticket_len = ticket_len;
    session->ticket_lifetime = 86401;
#else
    (void) ticket_len;
#endif

#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
    session->mfl_code = 1;
#endif
#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
    session->trunc_hmac = 1;
#endif
#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
    session->encrypt_then_mac = 1;
#endif

    return 0;
}

/*
 * Perform data exchanging between \p ssl_1 and \p ssl_2 and check if the
 * message was sent in the correct number of fragments.
 *
 * /p ssl_1 and /p ssl_2    Endpoints represented by mbedtls_ssl_context. Both
 *                          of them must be initialized and connected beforehand.
 * /p msg_len_1 and /p msg_len_2 specify the size of the message to send.
 * /p expected_fragments_1 and /p expected_fragments_2 determine in how many
 *                          fragments the message should be sent.
 *      expected_fragments is 0: can be used for DTLS testing while the message
 *                          size is larger than MFL. In that case the message
 *                          cannot be fragmented and sent to the second endpoint.
 *                          This value can be used for negative tests.
 *      expected_fragments is 1: can be used for TLS/DTLS testing while the
 *                          message size is below MFL
 *      expected_fragments > 1: can be used for TLS testing while the message
 *                          size is larger than MFL
 *
 * \retval  0 on success, otherwise error code.
 */
int mbedtls_exchange_data(mbedtls_ssl_context *ssl_1,
                          int msg_len_1, const int expected_fragments_1,
                          mbedtls_ssl_context *ssl_2,
                          int msg_len_2, const int expected_fragments_2)
{
    unsigned char *msg_buf_1 = malloc(msg_len_1);
    unsigned char *msg_buf_2 = malloc(msg_len_2);
    unsigned char *in_buf_1  = malloc(msg_len_2);
    unsigned char *in_buf_2  = malloc(msg_len_1);
    int msg_type, ret = -1;

    /* Perform this test with two message types. At first use a message
     * consisting of only 0x00 for the client and only 0xFF for the server.
     * At the second time use message with generated data */
    for (msg_type = 0; msg_type < 2; msg_type++) {
        int written_1 = 0;
        int written_2 = 0;
        int read_1 = 0;
        int read_2 = 0;
        int fragments_1 = 0;
        int fragments_2 = 0;

        if (msg_type == 0) {
            memset(msg_buf_1, 0x00, msg_len_1);
            memset(msg_buf_2, 0xff, msg_len_2);
        } else {
            int i, j = 0;
            for (i = 0; i < msg_len_1; i++) {
                msg_buf_1[i] = j++ & 0xFF;
            }
            for (i = 0; i < msg_len_2; i++) {
                msg_buf_2[i] = (j -= 5) & 0xFF;
            }
        }

        while (read_1 < msg_len_2 || read_2 < msg_len_1) {
            /* ssl_1 sending */
            if (msg_len_1 > written_1) {
                ret = mbedtls_ssl_write_fragment(ssl_1, msg_buf_1,
                                                 msg_len_1, &written_1,
                                                 expected_fragments_1);
                if (expected_fragments_1 == 0) {
                    /* This error is expected when the message is too large and
                     * cannot be fragmented */
                    TEST_ASSERT(ret == MBEDTLS_ERR_SSL_BAD_INPUT_DATA);
                    msg_len_1 = 0;
                } else {
                    TEST_ASSERT(ret == 0);
                }
            }

            /* ssl_2 sending */
            if (msg_len_2 > written_2) {
                ret = mbedtls_ssl_write_fragment(ssl_2, msg_buf_2,
                                                 msg_len_2, &written_2,
                                                 expected_fragments_2);
                if (expected_fragments_2 == 0) {
                    /* This error is expected when the message is too large and
                     * cannot be fragmented */
                    TEST_ASSERT(ret == MBEDTLS_ERR_SSL_BAD_INPUT_DATA);
                    msg_len_2 = 0;
                } else {
                    TEST_ASSERT(ret == 0);
                }
            }

            /* ssl_1 reading */
            if (read_1 < msg_len_2) {
                ret = mbedtls_ssl_read_fragment(ssl_1, in_buf_1,
                                                msg_len_2, &read_1,
                                                &fragments_2,
                                                expected_fragments_2);
                TEST_ASSERT(ret == 0);
            }

            /* ssl_2 reading */
            if (read_2 < msg_len_1) {
                ret = mbedtls_ssl_read_fragment(ssl_2, in_buf_2,
                                                msg_len_1, &read_2,
                                                &fragments_1,
                                                expected_fragments_1);
                TEST_ASSERT(ret == 0);
            }
        }

        ret = -1;
        TEST_ASSERT(0 == memcmp(msg_buf_1, in_buf_2, msg_len_1));
        TEST_ASSERT(0 == memcmp(msg_buf_2, in_buf_1, msg_len_2));
        TEST_ASSERT(fragments_1 == expected_fragments_1);
        TEST_ASSERT(fragments_2 == expected_fragments_2);
    }

    ret = 0;

exit:
    free(msg_buf_1);
    free(in_buf_1);
    free(msg_buf_2);
    free(in_buf_2);

    return ret;
}

/*
 * Perform data exchanging between \p ssl_1 and \p ssl_2. Both of endpoints
 * must be initialized and connected beforehand.
 *
 * \retval  0 on success, otherwise error code.
 */
int exchange_data(mbedtls_ssl_context *ssl_1,
                  mbedtls_ssl_context *ssl_2)
{
    return mbedtls_exchange_data(ssl_1, 256, 1,
                                 ssl_2, 256, 1);
}

#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) && \
    defined(MBEDTLS_ENTROPY_C) && \
    defined(MBEDTLS_CTR_DRBG_C)
void perform_handshake(handshake_test_options *options)
{
    /* forced_ciphersuite needs to last until the end of the handshake */
    int forced_ciphersuite[2];
    enum { BUFFSIZE = 17000 };
    mbedtls_endpoint client, server;
#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
    const char *psk_identity = "foo";
#endif
#if defined(MBEDTLS_TIMING_C)
    mbedtls_timing_delay_context timer_client, timer_server;
#endif
#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
    unsigned char *context_buf = NULL;
    size_t context_buf_len;
#endif
#if defined(MBEDTLS_SSL_RENEGOTIATION)
    int ret = -1;
#endif
    int expected_handshake_result = 0;

    USE_PSA_INIT();
    mbedtls_platform_zeroize(&client, sizeof(client));
    mbedtls_platform_zeroize(&server, sizeof(server));

    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    /* Client side */
    if (options->dtls != 0) {
        TEST_ASSERT(mbedtls_endpoint_init(&client, MBEDTLS_SSL_IS_CLIENT,
                                          options->pk_alg, &client_context,
                                          &client_queue,
                                          &server_queue, NULL) == 0);
#if defined(MBEDTLS_TIMING_C)
        mbedtls_ssl_set_timer_cb(&client.ssl, &timer_client,
                                 mbedtls_timing_set_delay,
                                 mbedtls_timing_get_delay);
#endif
    } else {
        TEST_ASSERT(mbedtls_endpoint_init(&client, MBEDTLS_SSL_IS_CLIENT,
                                          options->pk_alg, NULL, NULL,
                                          NULL, NULL) == 0);
    }

    if (options->client_min_version != TEST_SSL_MINOR_VERSION_NONE) {
        mbedtls_ssl_conf_min_version(&client.conf, MBEDTLS_SSL_MAJOR_VERSION_3,
                                     options->client_min_version);
    }

    if (options->client_max_version != TEST_SSL_MINOR_VERSION_NONE) {
        mbedtls_ssl_conf_max_version(&client.conf, MBEDTLS_SSL_MAJOR_VERSION_3,
                                     options->client_max_version);
    }

    if (strlen(options->cipher) > 0) {
        set_ciphersuite(&client.conf, options->cipher, forced_ciphersuite);
    }

#if defined(MBEDTLS_DEBUG_C)
    if (options->cli_log_fun) {
        mbedtls_debug_set_threshold(4);
        mbedtls_ssl_conf_dbg(&client.conf, options->cli_log_fun,
                             options->cli_log_obj);
    }
#endif

    /* Server side */
    if (options->dtls != 0) {
        TEST_ASSERT(mbedtls_endpoint_init(&server, MBEDTLS_SSL_IS_SERVER,
                                          options->pk_alg, &server_context,
                                          &server_queue,
                                          &client_queue, NULL) == 0);
#if defined(MBEDTLS_TIMING_C)
        mbedtls_ssl_set_timer_cb(&server.ssl, &timer_server,
                                 mbedtls_timing_set_delay,
                                 mbedtls_timing_get_delay);
#endif
    } else {
        TEST_ASSERT(mbedtls_endpoint_init(&server, MBEDTLS_SSL_IS_SERVER,
                                          options->pk_alg, NULL, NULL,
                                          NULL, NULL) == 0);
    }

    mbedtls_ssl_conf_authmode(&server.conf, options->srv_auth_mode);

    if (options->server_min_version != TEST_SSL_MINOR_VERSION_NONE) {
        mbedtls_ssl_conf_min_version(&server.conf, MBEDTLS_SSL_MAJOR_VERSION_3,
                                     options->server_min_version);
    }

    if (options->server_max_version != TEST_SSL_MINOR_VERSION_NONE) {
        mbedtls_ssl_conf_max_version(&server.conf, MBEDTLS_SSL_MAJOR_VERSION_3,
                                     options->server_max_version);
    }

#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
    TEST_ASSERT(mbedtls_ssl_conf_max_frag_len(&(server.conf),
                                              (unsigned char) options->mfl) == 0);
    TEST_ASSERT(mbedtls_ssl_conf_max_frag_len(&(client.conf),
                                              (unsigned char) options->mfl) == 0);
#else
    TEST_ASSERT(MBEDTLS_SSL_MAX_FRAG_LEN_NONE == options->mfl);
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */

#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
    if (options->psk_str != NULL && options->psk_str->len > 0) {
        TEST_ASSERT(mbedtls_ssl_conf_psk(&client.conf, options->psk_str->x,
                                         options->psk_str->len,
                                         (const unsigned char *) psk_identity,
                                         strlen(psk_identity)) == 0);

        TEST_ASSERT(mbedtls_ssl_conf_psk(&server.conf, options->psk_str->x,
                                         options->psk_str->len,
                                         (const unsigned char *) psk_identity,
                                         strlen(psk_identity)) == 0);

        mbedtls_ssl_conf_psk_cb(&server.conf, psk_dummy_callback, NULL);
    }
#endif
#if defined(MBEDTLS_SSL_RENEGOTIATION)
    if (options->renegotiate) {
        mbedtls_ssl_conf_renegotiation(&(server.conf),
                                       MBEDTLS_SSL_RENEGOTIATION_ENABLED);
        mbedtls_ssl_conf_renegotiation(&(client.conf),
                                       MBEDTLS_SSL_RENEGOTIATION_ENABLED);

        mbedtls_ssl_conf_legacy_renegotiation(&(server.conf),
                                              options->legacy_renegotiation);
        mbedtls_ssl_conf_legacy_renegotiation(&(client.conf),
                                              options->legacy_renegotiation);
    }
#endif /* MBEDTLS_SSL_RENEGOTIATION */

#if defined(MBEDTLS_DEBUG_C)
    if (options->srv_log_fun) {
        mbedtls_debug_set_threshold(4);
        mbedtls_ssl_conf_dbg(&server.conf, options->srv_log_fun,
                             options->srv_log_obj);
    }
#endif

    TEST_ASSERT(mbedtls_mock_socket_connect(&(client.socket),
                                            &(server.socket),
                                            BUFFSIZE) == 0);

#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
    if (options->resize_buffers != 0) {
        /* Ensure that the buffer sizes are appropriate before resizes */
        TEST_ASSERT(client.ssl.out_buf_len == MBEDTLS_SSL_OUT_BUFFER_LEN);
        TEST_ASSERT(client.ssl.in_buf_len == MBEDTLS_SSL_IN_BUFFER_LEN);
        TEST_ASSERT(server.ssl.out_buf_len == MBEDTLS_SSL_OUT_BUFFER_LEN);
        TEST_ASSERT(server.ssl.in_buf_len == MBEDTLS_SSL_IN_BUFFER_LEN);
    }
#endif

    if (options->expected_negotiated_version == TEST_SSL_MINOR_VERSION_NONE) {
        expected_handshake_result = MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION;
    }

    TEST_ASSERT(mbedtls_move_handshake_to_state(&(client.ssl),
                                                &(server.ssl),
                                                MBEDTLS_SSL_HANDSHAKE_OVER)
                ==  expected_handshake_result);

    if (expected_handshake_result != 0) {
        /* Connection will have failed by this point, skip to cleanup */
        goto exit;
    }

    TEST_ASSERT(client.ssl.state == MBEDTLS_SSL_HANDSHAKE_OVER);
    TEST_ASSERT(server.ssl.state == MBEDTLS_SSL_HANDSHAKE_OVER);

    /* Check that we agree on the version... */
    TEST_ASSERT(client.ssl.minor_ver == server.ssl.minor_ver);

    /* And check that the version negotiated is the expected one. */
    TEST_EQUAL(client.ssl.minor_ver, options->expected_negotiated_version);

#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
    if (options->resize_buffers != 0) {
        if (options->expected_negotiated_version != MBEDTLS_SSL_MINOR_VERSION_0 &&
            options->expected_negotiated_version != MBEDTLS_SSL_MINOR_VERSION_1) {
            /* A server, when using DTLS, might delay a buffer resize to happen
             * after it receives a message, so we force it. */
            TEST_ASSERT(exchange_data(&(client.ssl), &(server.ssl)) == 0);

            TEST_ASSERT(client.ssl.out_buf_len ==
                        mbedtls_ssl_get_output_buflen(&client.ssl));
            TEST_ASSERT(client.ssl.in_buf_len ==
                        mbedtls_ssl_get_input_buflen(&client.ssl));
            TEST_ASSERT(server.ssl.out_buf_len ==
                        mbedtls_ssl_get_output_buflen(&server.ssl));
            TEST_ASSERT(server.ssl.in_buf_len ==
                        mbedtls_ssl_get_input_buflen(&server.ssl));
        }
    }
#endif

    if (options->cli_msg_len != 0 || options->srv_msg_len != 0) {
        /* Start data exchanging test */
        TEST_ASSERT(mbedtls_exchange_data(&(client.ssl), options->cli_msg_len,
                                          options->expected_cli_fragments,
                                          &(server.ssl), options->srv_msg_len,
                                          options->expected_srv_fragments)
                    == 0);
    }
#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
    if (options->serialize == 1) {
        TEST_ASSERT(options->dtls == 1);

        TEST_ASSERT(mbedtls_ssl_context_save(&(server.ssl), NULL,
                                             0, &context_buf_len)
                    == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL);

        context_buf = mbedtls_calloc(1, context_buf_len);
        TEST_ASSERT(context_buf != NULL);

        TEST_ASSERT(mbedtls_ssl_context_save(&(server.ssl), context_buf,
                                             context_buf_len,
                                             &context_buf_len) == 0);

        mbedtls_ssl_free(&(server.ssl));
        mbedtls_ssl_init(&(server.ssl));

        TEST_ASSERT(mbedtls_ssl_setup(&(server.ssl), &(server.conf)) == 0);

        mbedtls_ssl_set_bio(&(server.ssl), &server_context,
                            mbedtls_mock_tcp_send_msg,
                            mbedtls_mock_tcp_recv_msg,
                            NULL);

#if defined(MBEDTLS_TIMING_C)
        mbedtls_ssl_set_timer_cb(&server.ssl, &timer_server,
                                 mbedtls_timing_set_delay,
                                 mbedtls_timing_get_delay);
#endif
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
        if (options->resize_buffers != 0) {
            /* Ensure that the buffer sizes are appropriate before resizes */
            TEST_ASSERT(server.ssl.out_buf_len == MBEDTLS_SSL_OUT_BUFFER_LEN);
            TEST_ASSERT(server.ssl.in_buf_len == MBEDTLS_SSL_IN_BUFFER_LEN);
        }
#endif
        TEST_ASSERT(mbedtls_ssl_context_load(&(server.ssl), context_buf,
                                             context_buf_len) == 0);

#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
        /* Validate buffer sizes after context deserialization */
        if (options->resize_buffers != 0) {
            TEST_ASSERT(server.ssl.out_buf_len ==
                        mbedtls_ssl_get_output_buflen(&server.ssl));
            TEST_ASSERT(server.ssl.in_buf_len ==
                        mbedtls_ssl_get_input_buflen(&server.ssl));
        }
#endif
        /* Retest writing/reading */
        if (options->cli_msg_len != 0 || options->srv_msg_len != 0) {
            TEST_ASSERT(mbedtls_exchange_data(&(client.ssl),
                                              options->cli_msg_len,
                                              options->expected_cli_fragments,
                                              &(server.ssl),
                                              options->srv_msg_len,
                                              options->expected_srv_fragments)
                        == 0);
        }
    }
#endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */

#if defined(MBEDTLS_SSL_RENEGOTIATION)
    if (options->renegotiate) {
        /* Start test with renegotiation */
        TEST_ASSERT(server.ssl.renego_status ==
                    MBEDTLS_SSL_INITIAL_HANDSHAKE);
        TEST_ASSERT(client.ssl.renego_status ==
                    MBEDTLS_SSL_INITIAL_HANDSHAKE);

        /* After calling this function for the server, it only sends a handshake
         * request. All renegotiation should happen during data exchanging */
        TEST_ASSERT(mbedtls_ssl_renegotiate(&(server.ssl)) == 0);
        TEST_ASSERT(server.ssl.renego_status ==
                    MBEDTLS_SSL_RENEGOTIATION_PENDING);
        TEST_ASSERT(client.ssl.renego_status ==
                    MBEDTLS_SSL_INITIAL_HANDSHAKE);

        TEST_ASSERT(exchange_data(&(client.ssl), &(server.ssl)) == 0);
        TEST_ASSERT(server.ssl.renego_status ==
                    MBEDTLS_SSL_RENEGOTIATION_DONE);
        TEST_ASSERT(client.ssl.renego_status ==
                    MBEDTLS_SSL_RENEGOTIATION_DONE);

        /* After calling mbedtls_ssl_renegotiate for the client all renegotiation
         * should happen inside this function. However in this test, we cannot
         * perform simultaneous communication between client and server so this
         * function will return waiting error on the socket. All rest of
         * renegotiation should happen during data exchanging */
        ret = mbedtls_ssl_renegotiate(&(client.ssl));
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
        if (options->resize_buffers != 0) {
            /* Ensure that the buffer sizes are appropriate before resizes */
            TEST_ASSERT(client.ssl.out_buf_len == MBEDTLS_SSL_OUT_BUFFER_LEN);
            TEST_ASSERT(client.ssl.in_buf_len == MBEDTLS_SSL_IN_BUFFER_LEN);
        }
#endif
        TEST_ASSERT(ret == 0 ||
                    ret == MBEDTLS_ERR_SSL_WANT_READ ||
                    ret == MBEDTLS_ERR_SSL_WANT_WRITE);
        TEST_ASSERT(server.ssl.renego_status ==
                    MBEDTLS_SSL_RENEGOTIATION_DONE);
        TEST_ASSERT(client.ssl.renego_status ==
                    MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS);

        TEST_ASSERT(exchange_data(&(client.ssl), &(server.ssl)) == 0);
        TEST_ASSERT(server.ssl.renego_status ==
                    MBEDTLS_SSL_RENEGOTIATION_DONE);
        TEST_ASSERT(client.ssl.renego_status ==
                    MBEDTLS_SSL_RENEGOTIATION_DONE);
#if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
        /* Validate buffer sizes after renegotiation */
        if (options->resize_buffers != 0) {
            TEST_ASSERT(client.ssl.out_buf_len ==
                        mbedtls_ssl_get_output_buflen(&client.ssl));
            TEST_ASSERT(client.ssl.in_buf_len ==
                        mbedtls_ssl_get_input_buflen(&client.ssl));
            TEST_ASSERT(server.ssl.out_buf_len ==
                        mbedtls_ssl_get_output_buflen(&server.ssl));
            TEST_ASSERT(server.ssl.in_buf_len ==
                        mbedtls_ssl_get_input_buflen(&server.ssl));
        }
#endif /* MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH */
    }
#endif /* MBEDTLS_SSL_RENEGOTIATION */

exit:
    mbedtls_endpoint_free(&client, options->dtls != 0 ? &client_context : NULL);
    mbedtls_endpoint_free(&server, options->dtls != 0 ? &server_context : NULL);
#if defined(MBEDTLS_DEBUG_C)
    if (options->cli_log_fun || options->srv_log_fun) {
        mbedtls_debug_set_threshold(0);
    }
#endif
#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
    if (context_buf != NULL) {
        mbedtls_free(context_buf);
    }
#endif
}
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */

/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_SSL_TLS_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE */
void test_callback_buffer_sanity()
{
    enum { MSGLEN = 10 };
    mbedtls_test_buffer buf;
    unsigned char input[MSGLEN];
    unsigned char output[MSGLEN];

    memset(input, 0, sizeof(input));

    /* Make sure calling put and get on NULL buffer results in error. */
    TEST_ASSERT(mbedtls_test_buffer_put(NULL, input, sizeof(input))
                == -1);
    TEST_ASSERT(mbedtls_test_buffer_get(NULL, output, sizeof(output))
                == -1);
    TEST_ASSERT(mbedtls_test_buffer_put(NULL, NULL, sizeof(input)) == -1);

    TEST_ASSERT(mbedtls_test_buffer_put(NULL, NULL, 0) == -1);
    TEST_ASSERT(mbedtls_test_buffer_get(NULL, NULL, 0) == -1);

    /* Make sure calling put and get on a buffer that hasn't been set up results
     * in error. */
    mbedtls_test_buffer_init(&buf);

    TEST_ASSERT(mbedtls_test_buffer_put(&buf, input, sizeof(input)) == -1);
    TEST_ASSERT(mbedtls_test_buffer_get(&buf, output, sizeof(output))
                == -1);
    TEST_ASSERT(mbedtls_test_buffer_put(&buf, NULL, sizeof(input)) == -1);

    TEST_ASSERT(mbedtls_test_buffer_put(&buf, NULL, 0) == -1);
    TEST_ASSERT(mbedtls_test_buffer_get(&buf, NULL, 0) == -1);

    /* Make sure calling put and get on NULL input only results in
     * error if the length is not zero, and that a NULL output is valid for data
     * dropping.
     */

    TEST_ASSERT(mbedtls_test_buffer_setup(&buf, sizeof(input)) == 0);

    TEST_ASSERT(mbedtls_test_buffer_put(&buf, NULL, sizeof(input)) == -1);
    TEST_ASSERT(mbedtls_test_buffer_get(&buf, NULL, sizeof(output))
                == 0);
    TEST_ASSERT(mbedtls_test_buffer_put(&buf, NULL, 0) == 0);
    TEST_ASSERT(mbedtls_test_buffer_get(&buf, NULL, 0) == 0);

    /* Make sure calling put several times in the row is safe */

    TEST_ASSERT(mbedtls_test_buffer_put(&buf, input, sizeof(input))
                == sizeof(input));
    TEST_ASSERT(mbedtls_test_buffer_get(&buf, output, 2) == 2);
    TEST_ASSERT(mbedtls_test_buffer_put(&buf, input, 1) == 1);
    TEST_ASSERT(mbedtls_test_buffer_put(&buf, input, 2) == 1);
    TEST_ASSERT(mbedtls_test_buffer_put(&buf, input, 2) == 0);


exit:

    mbedtls_test_buffer_free(&buf);
}
/* END_CASE */

/*
 * Test if the implementation of `mbedtls_test_buffer` related functions is
 * correct and works as expected.
 *
 * That is
 *  - If we try to put in \p put1 bytes then we can put in \p put1_ret bytes.
 *  - Afterwards if we try to get \p get1 bytes then we can get \get1_ret bytes.
 *  - Next, if we try to put in \p put1 bytes then we can put in \p put1_ret
 *    bytes.
 *  - Afterwards if we try to get \p get1 bytes then we can get \get1_ret bytes.
 *  - All of the bytes we got match the bytes we put in in a FIFO manner.
 */

/* BEGIN_CASE */
void test_callback_buffer(int size, int put1, int put1_ret,
                          int get1, int get1_ret, int put2, int put2_ret,
                          int get2, int get2_ret)
{
    enum { ROUNDS = 2 };
    size_t put[ROUNDS];
    int put_ret[ROUNDS];
    size_t get[ROUNDS];
    int get_ret[ROUNDS];
    mbedtls_test_buffer buf;
    unsigned char *input = NULL;
    size_t input_len;
    unsigned char *output = NULL;
    size_t output_len;
    size_t i, j, written, read;

    mbedtls_test_buffer_init(&buf);
    TEST_ASSERT(mbedtls_test_buffer_setup(&buf, size) == 0);

    /* Check the sanity of input parameters and initialise local variables. That
     * is, ensure that the amount of data is not negative and that we are not
     * expecting more to put or get than we actually asked for. */
    TEST_ASSERT(put1 >= 0);
    put[0] = put1;
    put_ret[0] = put1_ret;
    TEST_ASSERT(put1_ret <= put1);
    TEST_ASSERT(put2 >= 0);
    put[1] = put2;
    put_ret[1] = put2_ret;
    TEST_ASSERT(put2_ret <= put2);

    TEST_ASSERT(get1 >= 0);
    get[0] = get1;
    get_ret[0] = get1_ret;
    TEST_ASSERT(get1_ret <= get1);
    TEST_ASSERT(get2 >= 0);
    get[1] = get2;
    get_ret[1] = get2_ret;
    TEST_ASSERT(get2_ret <= get2);

    input_len = 0;
    /* Calculate actual input and output lengths */
    for (j = 0; j < ROUNDS; j++) {
        if (put_ret[j] > 0) {
            input_len += put_ret[j];
        }
    }
    /* In order to always have a valid pointer we always allocate at least 1
     * byte. */
    if (input_len == 0) {
        input_len = 1;
    }
    ASSERT_ALLOC(input, input_len);

    output_len = 0;
    for (j = 0; j < ROUNDS; j++) {
        if (get_ret[j] > 0) {
            output_len += get_ret[j];
        }
    }
    TEST_ASSERT(output_len <= input_len);
    /* In order to always have a valid pointer we always allocate at least 1
     * byte. */
    if (output_len == 0) {
        output_len = 1;
    }
    ASSERT_ALLOC(output, output_len);

    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < input_len; i++) {
        input[i] = i & 0xFF;
    }

    written = read = 0;
    for (j = 0; j < ROUNDS; j++) {
        TEST_ASSERT(put_ret[j] == mbedtls_test_buffer_put(&buf,
                                                          input + written, put[j]));
        written += put_ret[j];
        TEST_ASSERT(get_ret[j] == mbedtls_test_buffer_get(&buf,
                                                          output + read, get[j]));
        read += get_ret[j];
        TEST_ASSERT(read <= written);
        if (get_ret[j] > 0) {
            TEST_ASSERT(memcmp(output + read - get_ret[j],
                               input + read - get_ret[j], get_ret[j])
                        == 0);
        }
    }

exit:

    mbedtls_free(input);
    mbedtls_free(output);
    mbedtls_test_buffer_free(&buf);
}
/* END_CASE */

/*
 * Test if the implementation of `mbedtls_mock_socket` related I/O functions is
 * correct and works as expected on unconnected sockets.
 */

/* BEGIN_CASE */
void ssl_mock_sanity()
{
    enum { MSGLEN = 105 };
    unsigned char message[MSGLEN] = { 0 };
    unsigned char received[MSGLEN] = { 0 };
    mbedtls_mock_socket socket;

    mbedtls_mock_socket_init(&socket);
    TEST_ASSERT(mbedtls_mock_tcp_send_b(&socket, message, MSGLEN) < 0);
    mbedtls_mock_socket_close(&socket);
    mbedtls_mock_socket_init(&socket);
    TEST_ASSERT(mbedtls_mock_tcp_recv_b(&socket, received, MSGLEN) < 0);
    mbedtls_mock_socket_close(&socket);

    mbedtls_mock_socket_init(&socket);
    TEST_ASSERT(mbedtls_mock_tcp_send_nb(&socket, message, MSGLEN) < 0);
    mbedtls_mock_socket_close(&socket);
    mbedtls_mock_socket_init(&socket);
    TEST_ASSERT(mbedtls_mock_tcp_recv_nb(&socket, received, MSGLEN) < 0);
    mbedtls_mock_socket_close(&socket);

exit:

    mbedtls_mock_socket_close(&socket);
}
/* END_CASE */

/*
 * Test if the implementation of `mbedtls_mock_socket` related functions can
 * send a single message from the client to the server.
 */

/* BEGIN_CASE */
void ssl_mock_tcp(int blocking)
{
    enum { MSGLEN = 105 };
    enum { BUFLEN = MSGLEN / 5 };
    unsigned char message[MSGLEN];
    unsigned char received[MSGLEN];
    mbedtls_mock_socket client;
    mbedtls_mock_socket server;
    size_t written, read;
    int send_ret, recv_ret;
    mbedtls_ssl_send_t *send;
    mbedtls_ssl_recv_t *recv;
    unsigned i;

    if (blocking == 0) {
        send = mbedtls_mock_tcp_send_nb;
        recv = mbedtls_mock_tcp_recv_nb;
    } else {
        send = mbedtls_mock_tcp_send_b;
        recv = mbedtls_mock_tcp_recv_b;
    }

    mbedtls_mock_socket_init(&client);
    mbedtls_mock_socket_init(&server);

    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < MSGLEN; i++) {
        message[i] = i & 0xFF;
    }

    /* Make sure that sending a message takes a few  iterations. */
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server, BUFLEN));

    /* Send the message to the server */
    send_ret = recv_ret = 1;
    written = read = 0;
    while (send_ret != 0 || recv_ret != 0) {
        send_ret = send(&client, message + written, MSGLEN - written);

        TEST_ASSERT(send_ret >= 0);
        TEST_ASSERT(send_ret <= BUFLEN);
        written += send_ret;

        /* If the buffer is full we can test blocking and non-blocking send */
        if (send_ret == BUFLEN) {
            int blocking_ret = send(&client, message, 1);
            if (blocking) {
                TEST_ASSERT(blocking_ret == 0);
            } else {
                TEST_ASSERT(blocking_ret == MBEDTLS_ERR_SSL_WANT_WRITE);
            }
        }

        recv_ret = recv(&server, received + read, MSGLEN - read);

        /* The result depends on whether any data was sent */
        if (send_ret > 0) {
            TEST_ASSERT(recv_ret > 0);
            TEST_ASSERT(recv_ret <= BUFLEN);
            read += recv_ret;
        } else if (blocking) {
            TEST_ASSERT(recv_ret == 0);
        } else {
            TEST_ASSERT(recv_ret == MBEDTLS_ERR_SSL_WANT_READ);
            recv_ret = 0;
        }

        /* If the buffer is empty we can test blocking and non-blocking read */
        if (recv_ret == BUFLEN) {
            int blocking_ret = recv(&server, received, 1);
            if (blocking) {
                TEST_ASSERT(blocking_ret == 0);
            } else {
                TEST_ASSERT(blocking_ret == MBEDTLS_ERR_SSL_WANT_READ);
            }
        }
    }
    TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);

exit:

    mbedtls_mock_socket_close(&client);
    mbedtls_mock_socket_close(&server);
}
/* END_CASE */

/*
 * Test if the implementation of `mbedtls_mock_socket` related functions can
 * send messages in both direction at the same time (with the I/O calls
 * interleaving).
 */

/* BEGIN_CASE */
void ssl_mock_tcp_interleaving(int blocking)
{
    enum { ROUNDS = 2 };
    enum { MSGLEN = 105 };
    enum { BUFLEN = MSGLEN / 5 };
    unsigned char message[ROUNDS][MSGLEN];
    unsigned char received[ROUNDS][MSGLEN];
    mbedtls_mock_socket client;
    mbedtls_mock_socket server;
    size_t written[ROUNDS];
    size_t read[ROUNDS];
    int send_ret[ROUNDS];
    int recv_ret[ROUNDS];
    unsigned i, j, progress;
    mbedtls_ssl_send_t *send;
    mbedtls_ssl_recv_t *recv;

    if (blocking == 0) {
        send = mbedtls_mock_tcp_send_nb;
        recv = mbedtls_mock_tcp_recv_nb;
    } else {
        send = mbedtls_mock_tcp_send_b;
        recv = mbedtls_mock_tcp_recv_b;
    }

    mbedtls_mock_socket_init(&client);
    mbedtls_mock_socket_init(&server);

    /* Fill up the buffers with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < ROUNDS; i++) {
        for (j = 0; j < MSGLEN; j++) {
            message[i][j] = (i * MSGLEN + j) & 0xFF;
        }
    }

    /* Make sure that sending a message takes a few  iterations. */
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server, BUFLEN));

    /* Send the message from both sides, interleaving. */
    progress = 1;
    for (i = 0; i < ROUNDS; i++) {
        written[i] = 0;
        read[i] = 0;
    }
    /* This loop does not stop as long as there was a successful write or read
     * of at least one byte on either side. */
    while (progress != 0) {
        mbedtls_mock_socket *socket;

        for (i = 0; i < ROUNDS; i++) {
            /* First sending is from the client */
            socket = (i % 2 == 0) ? (&client) : (&server);

            send_ret[i] = send(socket, message[i] + written[i],
                               MSGLEN - written[i]);
            TEST_ASSERT(send_ret[i] >= 0);
            TEST_ASSERT(send_ret[i] <= BUFLEN);
            written[i] += send_ret[i];

            /* If the buffer is full we can test blocking and non-blocking
             * send */
            if (send_ret[i] == BUFLEN) {
                int blocking_ret = send(socket, message[i], 1);
                if (blocking) {
                    TEST_ASSERT(blocking_ret == 0);
                } else {
                    TEST_ASSERT(blocking_ret == MBEDTLS_ERR_SSL_WANT_WRITE);
                }
            }
        }

        for (i = 0; i < ROUNDS; i++) {
            /* First receiving is from the server */
            socket = (i % 2 == 0) ? (&server) : (&client);

            recv_ret[i] = recv(socket, received[i] + read[i],
                               MSGLEN - read[i]);

            /* The result depends on whether any data was sent */
            if (send_ret[i] > 0) {
                TEST_ASSERT(recv_ret[i] > 0);
                TEST_ASSERT(recv_ret[i] <= BUFLEN);
                read[i] += recv_ret[i];
            } else if (blocking) {
                TEST_ASSERT(recv_ret[i] == 0);
            } else {
                TEST_ASSERT(recv_ret[i] == MBEDTLS_ERR_SSL_WANT_READ);
                recv_ret[i] = 0;
            }

            /* If the buffer is empty we can test blocking and non-blocking
             * read */
            if (recv_ret[i] == BUFLEN) {
                int blocking_ret = recv(socket, received[i], 1);
                if (blocking) {
                    TEST_ASSERT(blocking_ret == 0);
                } else {
                    TEST_ASSERT(blocking_ret == MBEDTLS_ERR_SSL_WANT_READ);
                }
            }
        }

        progress = 0;
        for (i = 0; i < ROUNDS; i++) {
            progress += send_ret[i] + recv_ret[i];
        }
    }

    for (i = 0; i < ROUNDS; i++) {
        TEST_ASSERT(memcmp(message[i], received[i], MSGLEN) == 0);
    }

exit:

    mbedtls_mock_socket_close(&client);
    mbedtls_mock_socket_close(&server);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_queue_sanity()
{
    mbedtls_test_message_queue queue;

    /* Trying to push/pull to an empty queue */
    TEST_ASSERT(mbedtls_test_message_queue_push_info(NULL, 1)
                == MBEDTLS_TEST_ERROR_ARG_NULL);
    TEST_ASSERT(mbedtls_test_message_queue_pop_info(NULL, 1)
                == MBEDTLS_TEST_ERROR_ARG_NULL);

    TEST_ASSERT(mbedtls_test_message_queue_setup(&queue, 3) == 0);
    TEST_ASSERT(queue.capacity == 3);
    TEST_ASSERT(queue.num == 0);

exit:
    mbedtls_test_message_queue_free(&queue);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_queue_basic()
{
    mbedtls_test_message_queue queue;

    TEST_ASSERT(mbedtls_test_message_queue_setup(&queue, 3) == 0);

    /* Sanity test - 3 pushes and 3 pops with sufficient space */
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 1) == 1);
    TEST_ASSERT(queue.capacity == 3);
    TEST_ASSERT(queue.num == 1);
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 1) == 1);
    TEST_ASSERT(queue.capacity == 3);
    TEST_ASSERT(queue.num == 2);
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 2) == 2);
    TEST_ASSERT(queue.capacity == 3);
    TEST_ASSERT(queue.num == 3);

    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 1) == 1);
    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 1) == 1);
    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 2) == 2);

exit:
    mbedtls_test_message_queue_free(&queue);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_queue_overflow_underflow()
{
    mbedtls_test_message_queue queue;

    TEST_ASSERT(mbedtls_test_message_queue_setup(&queue, 3) == 0);

    /* 4 pushes (last one with an error), 4 pops (last one with an error) */
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 1) == 1);
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 1) == 1);
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 2) == 2);
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 3)
                == MBEDTLS_ERR_SSL_WANT_WRITE);

    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 1) == 1);
    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 1) == 1);
    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 2) == 2);

    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 1)
                == MBEDTLS_ERR_SSL_WANT_READ);

exit:
    mbedtls_test_message_queue_free(&queue);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_queue_interleaved()
{
    mbedtls_test_message_queue queue;

    TEST_ASSERT(mbedtls_test_message_queue_setup(&queue, 3) == 0);

    /* Interleaved test - [2 pushes, 1 pop] twice, and then two pops
     * (to wrap around the buffer) */
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 1) == 1);
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 1) == 1);

    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 1) == 1);

    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 2) == 2);
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 3) == 3);

    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 1) == 1);
    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 2) == 2);

    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 5) == 5);
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, 8) == 8);

    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 3) == 3);

    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 5) == 5);

    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, 8) == 8);

exit:
    mbedtls_test_message_queue_free(&queue);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_queue_insufficient_buffer()
{
    mbedtls_test_message_queue queue;
    size_t message_len = 10;
    size_t buffer_len = 5;

    TEST_ASSERT(mbedtls_test_message_queue_setup(&queue, 1) == 0);

    /* Popping without a sufficient buffer */
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&queue, message_len)
                == (int) message_len);
    TEST_ASSERT(mbedtls_test_message_queue_pop_info(&queue, buffer_len)
                == (int) buffer_len);
exit:
    mbedtls_test_message_queue_free(&queue);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_mock_uninitialized()
{
    enum { MSGLEN = 10 };
    unsigned char message[MSGLEN] = { 0 }, received[MSGLEN];
    mbedtls_mock_socket client, server;
    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    /* Send with a NULL context */
    TEST_ASSERT(mbedtls_mock_tcp_send_msg(NULL, message, MSGLEN)
                == MBEDTLS_TEST_ERROR_CONTEXT_ERROR);

    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(NULL, message, MSGLEN)
                == MBEDTLS_TEST_ERROR_CONTEXT_ERROR);

    TEST_ASSERT(mbedtls_message_socket_setup(&server_queue, &client_queue, 1,
                                             &server,
                                             &server_context) == 0);

    TEST_ASSERT(mbedtls_message_socket_setup(&client_queue, &server_queue, 1,
                                             &client,
                                             &client_context) == 0);

    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message, MSGLEN)
                == MBEDTLS_TEST_ERROR_SEND_FAILED);

    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MBEDTLS_ERR_SSL_WANT_READ);

    /* Push directly to a queue to later simulate a disconnected behavior */
    TEST_ASSERT(mbedtls_test_message_queue_push_info(&server_queue, MSGLEN)
                == MSGLEN);

    /* Test if there's an error when trying to read from a disconnected
     * socket */
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MBEDTLS_TEST_ERROR_RECV_FAILED);
exit:
    mbedtls_message_socket_close(&server_context);
    mbedtls_message_socket_close(&client_context);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_mock_basic()
{
    enum { MSGLEN = 10 };
    unsigned char message[MSGLEN], received[MSGLEN];
    mbedtls_mock_socket client, server;
    unsigned i;
    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    TEST_ASSERT(mbedtls_message_socket_setup(&server_queue, &client_queue, 1,
                                             &server,
                                             &server_context) == 0);

    TEST_ASSERT(mbedtls_message_socket_setup(&client_queue, &server_queue, 1,
                                             &client,
                                             &client_context) == 0);

    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < MSGLEN; i++) {
        message[i] = i & 0xFF;
    }
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server,
                                                 MSGLEN));

    /* Send the message to the server */
    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN) == MSGLEN);

    /* Read from the server */
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MSGLEN);

    TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);
    memset(received, 0, MSGLEN);

    /* Send the message to the client */
    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&server_context, message,
                                          MSGLEN) == MSGLEN);

    /* Read from the client */
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&client_context, received, MSGLEN)
                == MSGLEN);
    TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);

exit:
    mbedtls_message_socket_close(&server_context);
    mbedtls_message_socket_close(&client_context);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_mock_queue_overflow_underflow()
{
    enum { MSGLEN = 10 };
    unsigned char message[MSGLEN], received[MSGLEN];
    mbedtls_mock_socket client, server;
    unsigned i;
    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    TEST_ASSERT(mbedtls_message_socket_setup(&server_queue, &client_queue, 2,
                                             &server,
                                             &server_context) == 0);

    TEST_ASSERT(mbedtls_message_socket_setup(&client_queue, &server_queue, 2,
                                             &client,
                                             &client_context) == 0);

    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < MSGLEN; i++) {
        message[i] = i & 0xFF;
    }
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server,
                                                 MSGLEN*2));

    /* Send three message to the server, last one with an error */
    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN - 1) == MSGLEN - 1);

    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN) == MSGLEN);

    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN)
                == MBEDTLS_ERR_SSL_WANT_WRITE);

    /* Read three messages from the server, last one with an error */
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received,
                                          MSGLEN - 1) == MSGLEN - 1);

    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MSGLEN);

    TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);

    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MBEDTLS_ERR_SSL_WANT_READ);

exit:
    mbedtls_message_socket_close(&server_context);
    mbedtls_message_socket_close(&client_context);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_mock_socket_overflow()
{
    enum { MSGLEN = 10 };
    unsigned char message[MSGLEN], received[MSGLEN];
    mbedtls_mock_socket client, server;
    unsigned i;
    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    TEST_ASSERT(mbedtls_message_socket_setup(&server_queue, &client_queue, 2,
                                             &server,
                                             &server_context) == 0);

    TEST_ASSERT(mbedtls_message_socket_setup(&client_queue, &server_queue, 2,
                                             &client,
                                             &client_context) == 0);

    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < MSGLEN; i++) {
        message[i] = i & 0xFF;
    }
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server,
                                                 MSGLEN));

    /* Send two message to the server, second one with an error */
    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN) == MSGLEN);

    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN)
                == MBEDTLS_TEST_ERROR_SEND_FAILED);

    /* Read the only message from the server */
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MSGLEN);

    TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);

exit:
    mbedtls_message_socket_close(&server_context);
    mbedtls_message_socket_close(&client_context);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_mock_truncated()
{
    enum { MSGLEN = 10 };
    unsigned char message[MSGLEN], received[MSGLEN];
    mbedtls_mock_socket client, server;
    unsigned i;
    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    TEST_ASSERT(mbedtls_message_socket_setup(&server_queue, &client_queue, 2,
                                             &server,
                                             &server_context) == 0);

    TEST_ASSERT(mbedtls_message_socket_setup(&client_queue, &server_queue, 2,
                                             &client,
                                             &client_context) == 0);

    memset(received, 0, MSGLEN);
    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < MSGLEN; i++) {
        message[i] = i & 0xFF;
    }
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server,
                                                 2 * MSGLEN));

    /* Send two messages to the server, the second one small enough to fit in the
     * receiver's buffer. */
    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN) == MSGLEN);
    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN / 2) == MSGLEN / 2);
    /* Read a truncated message from the server */
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN/2)
                == MSGLEN/2);

    /* Test that the first half of the message is valid, and second one isn't */
    TEST_ASSERT(memcmp(message, received, MSGLEN/2) == 0);
    TEST_ASSERT(memcmp(message + MSGLEN/2, received + MSGLEN/2, MSGLEN/2)
                != 0);
    memset(received, 0, MSGLEN);

    /* Read a full message from the server */
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN/2)
                == MSGLEN / 2);

    /* Test that the first half of the message is valid */
    TEST_ASSERT(memcmp(message, received, MSGLEN/2) == 0);

exit:
    mbedtls_message_socket_close(&server_context);
    mbedtls_message_socket_close(&client_context);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_mock_socket_read_error()
{
    enum { MSGLEN = 10 };
    unsigned char message[MSGLEN], received[MSGLEN];
    mbedtls_mock_socket client, server;
    unsigned i;
    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    TEST_ASSERT(mbedtls_message_socket_setup(&server_queue, &client_queue, 1,
                                             &server,
                                             &server_context) == 0);

    TEST_ASSERT(mbedtls_message_socket_setup(&client_queue, &server_queue, 1,
                                             &client,
                                             &client_context) == 0);

    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < MSGLEN; i++) {
        message[i] = i & 0xFF;
    }
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server,
                                                 MSGLEN));

    TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                          MSGLEN) == MSGLEN);

    /* Force a read error by disconnecting the socket by hand */
    server.status = 0;
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MBEDTLS_TEST_ERROR_RECV_FAILED);
    /* Return to a valid state */
    server.status = MBEDTLS_MOCK_SOCKET_CONNECTED;

    memset(received, 0, sizeof(received));

    /* Test that even though the server tried to read once disconnected, the
     * continuity is preserved */
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MSGLEN);

    TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);

exit:
    mbedtls_message_socket_close(&server_context);
    mbedtls_message_socket_close(&client_context);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_mock_interleaved_one_way()
{
    enum { MSGLEN = 10 };
    unsigned char message[MSGLEN], received[MSGLEN];
    mbedtls_mock_socket client, server;
    unsigned i;
    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    TEST_ASSERT(mbedtls_message_socket_setup(&server_queue, &client_queue, 3,
                                             &server,
                                             &server_context) == 0);

    TEST_ASSERT(mbedtls_message_socket_setup(&client_queue, &server_queue, 3,
                                             &client,
                                             &client_context) == 0);

    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < MSGLEN; i++) {
        message[i] = i & 0xFF;
    }
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server,
                                                 MSGLEN*3));

    /* Interleaved test - [2 sends, 1 read] twice, and then two reads
     * (to wrap around the buffer) */
    for (i = 0; i < 2; i++) {
        TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received,
                                              MSGLEN) == MSGLEN);
        TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);
        memset(received, 0, sizeof(received));
    }

    for (i = 0; i < 2; i++) {
        TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);
    }
    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MBEDTLS_ERR_SSL_WANT_READ);
exit:
    mbedtls_message_socket_close(&server_context);
    mbedtls_message_socket_close(&client_context);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_message_mock_interleaved_two_ways()
{
    enum { MSGLEN = 10 };
    unsigned char message[MSGLEN], received[MSGLEN];
    mbedtls_mock_socket client, server;
    unsigned i;
    mbedtls_test_message_queue server_queue, client_queue;
    mbedtls_test_message_socket_context server_context, client_context;
    mbedtls_message_socket_init(&server_context);
    mbedtls_message_socket_init(&client_context);

    TEST_ASSERT(mbedtls_message_socket_setup(&server_queue, &client_queue, 3,
                                             &server,
                                             &server_context) == 0);

    TEST_ASSERT(mbedtls_message_socket_setup(&client_queue, &server_queue, 3,
                                             &client,
                                             &client_context) == 0);

    /* Fill up the buffer with structured data so that unwanted changes
     * can be detected */
    for (i = 0; i < MSGLEN; i++) {
        message[i] = i & 0xFF;
    }
    TEST_ASSERT(0 == mbedtls_mock_socket_connect(&client, &server,
                                                 MSGLEN*3));

    /* Interleaved test - [2 sends, 1 read] twice, both ways, and then two reads
     * (to wrap around the buffer) both ways. */
    for (i = 0; i < 2; i++) {
        TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(mbedtls_mock_tcp_send_msg(&client_context, message,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(mbedtls_mock_tcp_send_msg(&server_context, message,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(mbedtls_mock_tcp_send_msg(&server_context, message,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);

        memset(received, 0, sizeof(received));

        TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&client_context, received,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);

        memset(received, 0, sizeof(received));
    }

    for (i = 0; i < 2; i++) {
        TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);
        memset(received, 0, sizeof(received));

        TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&client_context, received,
                                              MSGLEN) == MSGLEN);

        TEST_ASSERT(memcmp(message, received, MSGLEN) == 0);
        memset(received, 0, sizeof(received));
    }

    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&server_context, received, MSGLEN)
                == MBEDTLS_ERR_SSL_WANT_READ);

    TEST_ASSERT(mbedtls_mock_tcp_recv_msg(&client_context, received, MSGLEN)
                == MBEDTLS_ERR_SSL_WANT_READ);
exit:
    mbedtls_message_socket_close(&server_context);
    mbedtls_message_socket_close(&client_context);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_SSL_DTLS_ANTI_REPLAY */
void ssl_dtls_replay(data_t *prevs, data_t *new, int ret)
{
    uint32_t len = 0;
    mbedtls_ssl_context ssl;
    mbedtls_ssl_config conf;

    mbedtls_ssl_init(&ssl);
    mbedtls_ssl_config_init(&conf);

    TEST_ASSERT(mbedtls_ssl_config_defaults(&conf,
                                            MBEDTLS_SSL_IS_CLIENT,
                                            MBEDTLS_SSL_TRANSPORT_DATAGRAM,
                                            MBEDTLS_SSL_PRESET_DEFAULT) == 0);
    TEST_ASSERT(mbedtls_ssl_setup(&ssl, &conf) == 0);

    /* Read previous record numbers */
    for (len = 0; len < prevs->len; len += 6) {
        memcpy(ssl.in_ctr + 2, prevs->x + len, 6);
        mbedtls_ssl_dtls_replay_update(&ssl);
    }

    /* Check new number */
    memcpy(ssl.in_ctr + 2, new->x, 6);
    TEST_ASSERT(mbedtls_ssl_dtls_replay_check(&ssl) == ret);

    mbedtls_ssl_free(&ssl);
    mbedtls_ssl_config_free(&conf);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
void ssl_set_hostname_twice(char *hostname0, char *hostname1)
{
    mbedtls_ssl_context ssl;
    mbedtls_ssl_init(&ssl);

    TEST_ASSERT(mbedtls_ssl_set_hostname(&ssl, hostname0) == 0);
    TEST_ASSERT(mbedtls_ssl_set_hostname(&ssl, hostname1) == 0);

    mbedtls_ssl_free(&ssl);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_crypt_record(int cipher_type, int hash_id,
                      int etm, int tag_mode, int ver,
                      int cid0_len, int cid1_len)
{
    /*
     * Test several record encryptions and decryptions
     * with plenty of space before and after the data
     * within the record buffer.
     */

    int ret;
    int num_records = 16;
    mbedtls_ssl_context ssl; /* ONLY for debugging */

    mbedtls_ssl_transform t0, t1;
    unsigned char *buf = NULL;
    size_t const buflen = 512;
    mbedtls_record rec, rec_backup;

    mbedtls_ssl_init(&ssl);
    mbedtls_ssl_transform_init(&t0);
    mbedtls_ssl_transform_init(&t1);
    TEST_ASSERT(build_transforms(&t0, &t1, cipher_type, hash_id,
                                 etm, tag_mode, ver,
                                 (size_t) cid0_len,
                                 (size_t) cid1_len) == 0);

    TEST_ASSERT((buf = mbedtls_calloc(1, buflen)) != NULL);

    while (num_records-- > 0) {
        mbedtls_ssl_transform *t_dec, *t_enc;
        /* Take turns in who's sending and who's receiving. */
        if (num_records % 3 == 0) {
            t_dec = &t0;
            t_enc = &t1;
        } else {
            t_dec = &t1;
            t_enc = &t0;
        }

        /*
         * The record header affects the transformation in two ways:
         * 1) It determines the AEAD additional data
         * 2) The record counter sometimes determines the IV.
         *
         * Apart from that, the fields don't have influence.
         * In particular, it is currently not the responsibility
         * of ssl_encrypt/decrypt_buf to check if the transform
         * version matches the record version, or that the
         * type is sensible.
         */

        memset(rec.ctr, num_records, sizeof(rec.ctr));
        rec.type    = 42;
        rec.ver[0]  = num_records;
        rec.ver[1]  = num_records;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
        rec.cid_len = 0;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

        rec.buf     = buf;
        rec.buf_len = buflen;
        rec.data_offset = 16;
        /* Make sure to vary the length to exercise different
         * paddings. */
        rec.data_len = 1 + num_records;

        memset(rec.buf + rec.data_offset, 42, rec.data_len);

        /* Make a copy for later comparison */
        rec_backup = rec;

        /* Encrypt record */
        ret = mbedtls_ssl_encrypt_buf(&ssl, t_enc, &rec,
                                      mbedtls_test_rnd_std_rand, NULL);
        TEST_ASSERT(ret == 0 || ret == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL);
        if (ret != 0) {
            continue;
        }

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
        if (rec.cid_len != 0) {
            /* DTLS 1.2 + CID hides the real content type and
             * uses a special CID content type in the protected
             * record. Double-check this. */
            TEST_ASSERT(rec.type == MBEDTLS_SSL_MSG_CID);
        }
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
        if (t_enc->minor_ver == MBEDTLS_SSL_MINOR_VERSION_4) {
            /* TLS 1.3 hides the real content type and
             * always uses Application Data as the content type
             * for protected records. Double-check this. */
            TEST_ASSERT(rec.type == MBEDTLS_SSL_MSG_APPLICATION_DATA);
        }
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */

        /* Decrypt record with t_dec */
        ret = mbedtls_ssl_decrypt_buf(&ssl, t_dec, &rec);
        TEST_ASSERT(ret == 0);

        /* Compare results */
        TEST_ASSERT(rec.type == rec_backup.type);
        TEST_ASSERT(memcmp(rec.ctr, rec_backup.ctr, 8) == 0);
        TEST_ASSERT(rec.ver[0] == rec_backup.ver[0]);
        TEST_ASSERT(rec.ver[1] == rec_backup.ver[1]);
        TEST_ASSERT(rec.data_len == rec_backup.data_len);
        TEST_ASSERT(rec.data_offset == rec_backup.data_offset);
        TEST_ASSERT(memcmp(rec.buf + rec.data_offset,
                           rec_backup.buf + rec_backup.data_offset,
                           rec.data_len) == 0);
    }

exit:

    /* Cleanup */
    mbedtls_ssl_free(&ssl);
    mbedtls_ssl_transform_free(&t0);
    mbedtls_ssl_transform_free(&t1);

    mbedtls_free(buf);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_crypt_record_small(int cipher_type, int hash_id,
                            int etm, int tag_mode, int ver,
                            int cid0_len, int cid1_len)
{
    /*
     * Test pairs of encryption and decryption with an increasing
     * amount of space in the record buffer - in more detail:
     * 1) Try to encrypt with 0, 1, 2, ... bytes available
     *    in front of the plaintext, and expect the encryption
     *    to succeed starting from some offset. Always keep
     *    enough space in the end of the buffer.
     * 2) Try to encrypt with 0, 1, 2, ... bytes available
     *    at the end of the plaintext, and expect the encryption
     *    to succeed starting from some offset. Always keep
     *    enough space at the beginning of the buffer.
     * 3) Try to encrypt with 0, 1, 2, ... bytes available
     *    both at the front and end of the plaintext,
     *    and expect the encryption to succeed starting from
     *    some offset.
     *
     * If encryption succeeds, check that decryption succeeds
     * and yields the original record.
     */

    mbedtls_ssl_context ssl; /* ONLY for debugging */

    mbedtls_ssl_transform t0, t1;
    unsigned char *buf = NULL;
    size_t const buflen = 256;
    mbedtls_record rec, rec_backup;

    int ret;
    int mode;              /* Mode 1, 2 or 3 as explained above     */
    size_t offset;         /* Available space at beginning/end/both */
    size_t threshold = 96; /* Maximum offset to test against        */

    size_t default_pre_padding  = 64;  /* Pre-padding to use in mode 2  */
    size_t default_post_padding = 128; /* Post-padding to use in mode 1 */

    int seen_success; /* Indicates if in the current mode we've
                       * already seen a successful test. */

    mbedtls_ssl_init(&ssl);
    mbedtls_ssl_transform_init(&t0);
    mbedtls_ssl_transform_init(&t1);
    TEST_ASSERT(build_transforms(&t0, &t1, cipher_type, hash_id,
                                 etm, tag_mode, ver,
                                 (size_t) cid0_len,
                                 (size_t) cid1_len) == 0);

    TEST_ASSERT((buf = mbedtls_calloc(1, buflen)) != NULL);

    for (mode = 1; mode <= 3; mode++) {
        seen_success = 0;
        for (offset = 0; offset <= threshold; offset++) {
            mbedtls_ssl_transform *t_dec, *t_enc;
            t_dec = &t0;
            t_enc = &t1;

            memset(rec.ctr, offset, sizeof(rec.ctr));
            rec.type    = 42;
            rec.ver[0]  = offset;
            rec.ver[1]  = offset;
            rec.buf     = buf;
            rec.buf_len = buflen;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
            rec.cid_len = 0;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

            switch (mode) {
                case 1: /* Space in the beginning */
                    rec.data_offset = offset;
                    rec.data_len = buflen - offset - default_post_padding;
                    break;

                case 2: /* Space in the end */
                    rec.data_offset = default_pre_padding;
                    rec.data_len = buflen - default_pre_padding - offset;
                    break;

                case 3: /* Space in the beginning and end */
                    rec.data_offset = offset;
                    rec.data_len = buflen - 2 * offset;
                    break;

                default:
                    TEST_ASSERT(0);
                    break;
            }

            memset(rec.buf + rec.data_offset, 42, rec.data_len);

            /* Make a copy for later comparison */
            rec_backup = rec;

            /* Encrypt record */
            ret = mbedtls_ssl_encrypt_buf(&ssl, t_enc, &rec,
                                          mbedtls_test_rnd_std_rand, NULL);

            if ((mode == 1 || mode == 2) && seen_success) {
                TEST_ASSERT(ret == 0);
            } else {
                TEST_ASSERT(ret == 0 || ret == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL);
                if (ret == 0) {
                    seen_success = 1;
                }
            }

            if (ret != 0) {
                continue;
            }

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
            if (rec.cid_len != 0) {
                /* DTLS 1.2 + CID hides the real content type and
                 * uses a special CID content type in the protected
                 * record. Double-check this. */
                TEST_ASSERT(rec.type == MBEDTLS_SSL_MSG_CID);
            }
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
            if (t_enc->minor_ver == MBEDTLS_SSL_MINOR_VERSION_4) {
                /* TLS 1.3 hides the real content type and
                 * always uses Application Data as the content type
                 * for protected records. Double-check this. */
                TEST_ASSERT(rec.type == MBEDTLS_SSL_MSG_APPLICATION_DATA);
            }
#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */

            /* Decrypt record with t_dec */
            TEST_ASSERT(mbedtls_ssl_decrypt_buf(&ssl, t_dec, &rec) == 0);

            /* Compare results */
            TEST_ASSERT(rec.type == rec_backup.type);
            TEST_ASSERT(memcmp(rec.ctr, rec_backup.ctr, 8) == 0);
            TEST_ASSERT(rec.ver[0] == rec_backup.ver[0]);
            TEST_ASSERT(rec.ver[1] == rec_backup.ver[1]);
            TEST_ASSERT(rec.data_len == rec_backup.data_len);
            TEST_ASSERT(rec.data_offset == rec_backup.data_offset);
            TEST_ASSERT(memcmp(rec.buf + rec.data_offset,
                               rec_backup.buf + rec_backup.data_offset,
                               rec.data_len) == 0);
        }

        TEST_ASSERT(seen_success == 1);
    }

exit:

    /* Cleanup */
    mbedtls_ssl_free(&ssl);
    mbedtls_ssl_transform_free(&t0);
    mbedtls_ssl_transform_free(&t1);

    mbedtls_free(buf);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_AES_C:MBEDTLS_SSL_PROTO_TLS1_2 */
void ssl_decrypt_non_etm_cbc(int cipher_type, int hash_id, int trunc_hmac,
                             int length_selector)
{
    /*
     * Test record decryption for CBC without EtM, focused on the verification
     * of padding and MAC.
     *
     * Actually depends on TLS >= 1.0 (SSL 3.0 computes the MAC differently),
     * and either AES, ARIA, Camellia or DES, but since the test framework
     * doesn't support alternation in dependency statements, just depend on
     * TLS 1.2 and AES.
     *
     * The length_selector argument is interpreted as follows:
     * - if it's -1, the plaintext length is 0 and minimal padding is applied
     * - if it's -2, the plaintext length is 0 and maximal padding is applied
     * - otherwise it must be in [0, 255] and is padding_length from RFC 5246:
     *   it's the length of the rest of the padding, that is, excluding the
     *   byte that encodes the length. The minimal non-zero plaintext length
     *   that gives this padding_length is automatically selected.
     */
    mbedtls_ssl_context ssl; /* ONLY for debugging */
    mbedtls_ssl_transform t0, t1;
    mbedtls_record rec, rec_save;
    unsigned char *buf = NULL, *buf_save = NULL;
    size_t buflen, olen = 0;
    size_t plaintext_len, block_size, i;
    unsigned char padlen; /* excluding the padding_length byte */
    unsigned char add_data[13];
    unsigned char mac[MBEDTLS_MD_MAX_SIZE];
    int exp_ret;
    const unsigned char pad_max_len = 255; /* Per the standard */

    mbedtls_ssl_init(&ssl);
    mbedtls_ssl_transform_init(&t0);
    mbedtls_ssl_transform_init(&t1);

    /* Set up transforms with dummy keys */
    TEST_ASSERT(build_transforms(&t0, &t1, cipher_type, hash_id,
                                 0, trunc_hmac,
                                 MBEDTLS_SSL_MINOR_VERSION_3,
                                 0, 0) == 0);

    /* Determine padding/plaintext length */
    TEST_ASSERT(length_selector >= -2 && length_selector <= 255);
    block_size = t0.ivlen;
    if (length_selector < 0) {
        plaintext_len = 0;

        /* Minimal padding
         * The +1 is for the padding_length byte, not counted in padlen. */
        padlen = block_size - (t0.maclen + 1) % block_size;

        /* Maximal padding? */
        if (length_selector == -2) {
            padlen += block_size * ((pad_max_len - padlen) / block_size);
        }
    } else {
        padlen = length_selector;

        /* Minimal non-zero plaintext_length giving desired padding.
         * The +1 is for the padding_length byte, not counted in padlen. */
        plaintext_len = block_size - (padlen + t0.maclen + 1) % block_size;
    }

    /* Prepare a buffer for record data */
    buflen = block_size
             + plaintext_len
             + t0.maclen
             + padlen + 1;
    ASSERT_ALLOC(buf, buflen);
    ASSERT_ALLOC(buf_save, buflen);

    /* Prepare a dummy record header */
    memset(rec.ctr, 0, sizeof(rec.ctr));
    rec.type    = MBEDTLS_SSL_MSG_APPLICATION_DATA;
    rec.ver[0]  = MBEDTLS_SSL_MAJOR_VERSION_3;
    rec.ver[1]  = MBEDTLS_SSL_MINOR_VERSION_3;
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    rec.cid_len = 0;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

    /* Prepare dummy record content */
    rec.buf     = buf;
    rec.buf_len = buflen;
    rec.data_offset = block_size;
    rec.data_len = plaintext_len;
    memset(rec.buf + rec.data_offset, 42, rec.data_len);

    /* Serialized version of record header for MAC purposes */
    memcpy(add_data, rec.ctr, 8);
    add_data[8] = rec.type;
    add_data[9] = rec.ver[0];
    add_data[10] = rec.ver[1];
    add_data[11] = (rec.data_len >> 8) & 0xff;
    add_data[12] = (rec.data_len >> 0) & 0xff;

    /* Set dummy IV */
    memset(t0.iv_enc, 0x55, t0.ivlen);
    memcpy(rec.buf, t0.iv_enc, t0.ivlen);

    /*
     * Prepare a pre-encryption record (with MAC and padding), and save it.
     */

    /* MAC with additional data */
    TEST_EQUAL(0, mbedtls_md_hmac_update(&t0.md_ctx_enc, add_data, 13));
    TEST_EQUAL(0, mbedtls_md_hmac_update(&t0.md_ctx_enc,
                                         rec.buf + rec.data_offset,
                                         rec.data_len));
    TEST_EQUAL(0, mbedtls_md_hmac_finish(&t0.md_ctx_enc, mac));

    memcpy(rec.buf + rec.data_offset + rec.data_len, mac, t0.maclen);
    rec.data_len += t0.maclen;

    /* Pad */
    memset(rec.buf + rec.data_offset + rec.data_len, padlen, padlen + 1);
    rec.data_len += padlen + 1;

    /* Save correct pre-encryption record */
    rec_save = rec;
    rec_save.buf = buf_save;
    memcpy(buf_save, buf, buflen);

    /*
     * Encrypt and decrypt the correct record, expecting success
     */
    TEST_EQUAL(0, mbedtls_cipher_crypt(&t0.cipher_ctx_enc,
                                       t0.iv_enc, t0.ivlen,
                                       rec.buf + rec.data_offset, rec.data_len,
                                       rec.buf + rec.data_offset, &olen));
    rec.data_offset -= t0.ivlen;
    rec.data_len    += t0.ivlen;

    TEST_EQUAL(0, mbedtls_ssl_decrypt_buf(&ssl, &t1, &rec));

    /*
     * Modify each byte of the pre-encryption record before encrypting and
     * decrypting it, expecting failure every time.
     */
    for (i = block_size; i < buflen; i++) {
        mbedtls_test_set_step(i);

        /* Restore correct pre-encryption record */
        rec = rec_save;
        rec.buf = buf;
        memcpy(buf, buf_save, buflen);

        /* Corrupt one byte of the data (could be plaintext, MAC or padding) */
        rec.buf[i] ^= 0x01;

        /* Encrypt */
        TEST_EQUAL(0, mbedtls_cipher_crypt(&t0.cipher_ctx_enc,
                                           t0.iv_enc, t0.ivlen,
                                           rec.buf + rec.data_offset, rec.data_len,
                                           rec.buf + rec.data_offset, &olen));
        rec.data_offset -= t0.ivlen;
        rec.data_len    += t0.ivlen;

        /* Decrypt and expect failure */
        TEST_EQUAL(MBEDTLS_ERR_SSL_INVALID_MAC,
                   mbedtls_ssl_decrypt_buf(&ssl, &t1, &rec));
    }

    /*
     * Use larger values of the padding bytes - with small buffers, this tests
     * the case where the announced padlen would be larger than the buffer
     * (and before that, than the buffer minus the size of the MAC), to make
     * sure our padding checking code does not perform any out-of-bounds reads
     * in this case. (With larger buffers, ie when the plaintext is long or
     * maximal length padding is used, this is less relevant but still doesn't
     * hurt to test.)
     *
     * (Start the loop with correct padding, just to double-check that record
     * saving did work, and that we're overwriting the correct bytes.)
     */
    for (i = padlen; i <= pad_max_len; i++) {
        mbedtls_test_set_step(i);

        /* Restore correct pre-encryption record */
        rec = rec_save;
        rec.buf = buf;
        memcpy(buf, buf_save, buflen);

        /* Set padding bytes to new value */
        memset(buf + buflen - padlen - 1, i, padlen + 1);

        /* Encrypt */
        TEST_EQUAL(0, mbedtls_cipher_crypt(&t0.cipher_ctx_enc,
                                           t0.iv_enc, t0.ivlen,
                                           rec.buf + rec.data_offset, rec.data_len,
                                           rec.buf + rec.data_offset, &olen));
        rec.data_offset -= t0.ivlen;
        rec.data_len    += t0.ivlen;

        /* Decrypt and expect failure except the first time */
        exp_ret = (i == padlen) ? 0 : MBEDTLS_ERR_SSL_INVALID_MAC;
        TEST_EQUAL(exp_ret, mbedtls_ssl_decrypt_buf(&ssl, &t1, &rec));
    }

exit:
    mbedtls_ssl_free(&ssl);
    mbedtls_ssl_transform_free(&t0);
    mbedtls_ssl_transform_free(&t1);
    mbedtls_free(buf);
    mbedtls_free(buf_save);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
void ssl_tls1_3_hkdf_expand_label(int hash_alg,
                                  data_t *secret,
                                  int label_idx,
                                  data_t *ctx,
                                  int desired_length,
                                  data_t *expected)
{
    unsigned char dst[100];

    unsigned char const *lbl = NULL;
    size_t lbl_len;
#define MBEDTLS_SSL_TLS1_3_LABEL(name, string)                        \
    if (label_idx == (int) tls1_3_label_ ## name)                      \
    {                                                                   \
        lbl = mbedtls_ssl_tls1_3_labels.name;                           \
        lbl_len = sizeof(mbedtls_ssl_tls1_3_labels.name);             \
    }
    MBEDTLS_SSL_TLS1_3_LABEL_LIST
#undef MBEDTLS_SSL_TLS1_3_LABEL
    TEST_ASSERT(lbl != NULL);

    /* Check sanity of test parameters. */
    TEST_ASSERT((size_t) desired_length <= sizeof(dst));
    TEST_ASSERT((size_t) desired_length == expected->len);

    TEST_ASSERT(mbedtls_ssl_tls1_3_hkdf_expand_label(
                    (mbedtls_md_type_t) hash_alg,
                    secret->x, secret->len,
                    lbl, lbl_len,
                    ctx->x, ctx->len,
                    dst, desired_length) == 0);

    ASSERT_COMPARE(dst, (size_t) desired_length,
                   expected->x, (size_t) expected->len);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
void ssl_tls1_3_traffic_key_generation(int hash_alg,
                                       data_t *server_secret,
                                       data_t *client_secret,
                                       int desired_iv_len,
                                       int desired_key_len,
                                       data_t *expected_server_write_key,
                                       data_t *expected_server_write_iv,
                                       data_t *expected_client_write_key,
                                       data_t *expected_client_write_iv)
{
    mbedtls_ssl_key_set keys;

    /* Check sanity of test parameters. */
    TEST_ASSERT(client_secret->len == server_secret->len);
    TEST_ASSERT(expected_client_write_iv->len == expected_server_write_iv->len &&
                expected_client_write_iv->len == (size_t) desired_iv_len);
    TEST_ASSERT(expected_client_write_key->len == expected_server_write_key->len &&
                expected_client_write_key->len == (size_t) desired_key_len);

    TEST_ASSERT(mbedtls_ssl_tls1_3_make_traffic_keys(
                    (mbedtls_md_type_t) hash_alg,
                    client_secret->x,
                    server_secret->x,
                    client_secret->len /* == server_secret->len */,
                    desired_key_len, desired_iv_len,
                    &keys) == 0);

    ASSERT_COMPARE(keys.client_write_key,
                   keys.key_len,
                   expected_client_write_key->x,
                   (size_t) desired_key_len);
    ASSERT_COMPARE(keys.server_write_key,
                   keys.key_len,
                   expected_server_write_key->x,
                   (size_t) desired_key_len);
    ASSERT_COMPARE(keys.client_write_iv,
                   keys.iv_len,
                   expected_client_write_iv->x,
                   (size_t) desired_iv_len);
    ASSERT_COMPARE(keys.server_write_iv,
                   keys.iv_len,
                   expected_server_write_iv->x,
                   (size_t) desired_iv_len);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
void ssl_tls1_3_derive_secret(int hash_alg,
                              data_t *secret,
                              int label_idx,
                              data_t *ctx,
                              int desired_length,
                              int already_hashed,
                              data_t *expected)
{
    unsigned char dst[100];

    unsigned char const *lbl = NULL;
    size_t lbl_len;
#define MBEDTLS_SSL_TLS1_3_LABEL(name, string)                        \
    if (label_idx == (int) tls1_3_label_ ## name)                      \
    {                                                                   \
        lbl = mbedtls_ssl_tls1_3_labels.name;                           \
        lbl_len = sizeof(mbedtls_ssl_tls1_3_labels.name);             \
    }
    MBEDTLS_SSL_TLS1_3_LABEL_LIST
#undef MBEDTLS_SSL_TLS1_3_LABEL
    TEST_ASSERT(lbl != NULL);

    /* Check sanity of test parameters. */
    TEST_ASSERT((size_t) desired_length <= sizeof(dst));
    TEST_ASSERT((size_t) desired_length == expected->len);

    TEST_ASSERT(mbedtls_ssl_tls1_3_derive_secret(
                    (mbedtls_md_type_t) hash_alg,
                    secret->x, secret->len,
                    lbl, lbl_len,
                    ctx->x, ctx->len,
                    already_hashed,
                    dst, desired_length) == 0);

    ASSERT_COMPARE(dst, desired_length,
                   expected->x, desired_length);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
void ssl_tls1_3_key_evolution(int hash_alg,
                              data_t *secret,
                              data_t *input,
                              data_t *expected)
{
    unsigned char secret_new[MBEDTLS_MD_MAX_SIZE];

    TEST_ASSERT(mbedtls_ssl_tls1_3_evolve_secret(
                    (mbedtls_md_type_t) hash_alg,
                    secret->len ? secret->x : NULL,
                    input->len ? input->x : NULL, input->len,
                    secret_new) == 0);

    ASSERT_COMPARE(secret_new, (size_t) expected->len,
                   expected->x, (size_t) expected->len);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_tls_prf(int type, data_t *secret, data_t *random,
                 char *label, data_t *result_str, int exp_ret)
{
    unsigned char *output;

    output = mbedtls_calloc(1, result_str->len);
    if (output == NULL) {
        goto exit;
    }

    USE_PSA_INIT();

    TEST_ASSERT(mbedtls_ssl_tls_prf(type, secret->x, secret->len,
                                    label, random->x, random->len,
                                    output, result_str->len) == exp_ret);

    if (exp_ret == 0) {
        TEST_ASSERT(mbedtls_test_hexcmp(output, result_str->x,
                                        result_str->len, result_str->len) == 0);
    }
exit:

    mbedtls_free(output);
    USE_PSA_DONE();
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_serialize_session_save_load(int ticket_len, char *crt_file)
{
    mbedtls_ssl_session original, restored;
    unsigned char *buf = NULL;
    size_t len;

    /*
     * Test that a save-load pair is the identity
     */

    mbedtls_ssl_session_init(&original);
    mbedtls_ssl_session_init(&restored);

    /* Prepare a dummy session to work on */
    TEST_ASSERT(ssl_populate_session(&original, ticket_len, crt_file) == 0);

    /* Serialize it */
    TEST_ASSERT(mbedtls_ssl_session_save(&original, NULL, 0, &len)
                == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL);
    TEST_ASSERT((buf = mbedtls_calloc(1, len)) != NULL);
    TEST_ASSERT(mbedtls_ssl_session_save(&original, buf, len, &len)
                == 0);

    /* Restore session from serialized data */
    TEST_ASSERT(mbedtls_ssl_session_load(&restored, buf, len) == 0);

    /*
     * Make sure both session structures are identical
     */
#if defined(MBEDTLS_HAVE_TIME)
    TEST_ASSERT(original.start == restored.start);
#endif
    TEST_ASSERT(original.ciphersuite == restored.ciphersuite);
    TEST_ASSERT(original.compression == restored.compression);
    TEST_ASSERT(original.id_len == restored.id_len);
    TEST_ASSERT(memcmp(original.id,
                       restored.id, sizeof(original.id)) == 0);
    TEST_ASSERT(memcmp(original.master,
                       restored.master, sizeof(original.master)) == 0);

#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
    TEST_ASSERT((original.peer_cert == NULL) ==
                (restored.peer_cert == NULL));
    if (original.peer_cert != NULL) {
        TEST_ASSERT(original.peer_cert->raw.len ==
                    restored.peer_cert->raw.len);
        TEST_ASSERT(memcmp(original.peer_cert->raw.p,
                           restored.peer_cert->raw.p,
                           original.peer_cert->raw.len) == 0);
    }
#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
    TEST_ASSERT(original.peer_cert_digest_type ==
                restored.peer_cert_digest_type);
    TEST_ASSERT(original.peer_cert_digest_len ==
                restored.peer_cert_digest_len);
    TEST_ASSERT((original.peer_cert_digest == NULL) ==
                (restored.peer_cert_digest == NULL));
    if (original.peer_cert_digest != NULL) {
        TEST_ASSERT(memcmp(original.peer_cert_digest,
                           restored.peer_cert_digest,
                           original.peer_cert_digest_len) == 0);
    }
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
    TEST_ASSERT(original.verify_result == restored.verify_result);

#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
    TEST_ASSERT(original.ticket_len == restored.ticket_len);
    if (original.ticket_len != 0) {
        TEST_ASSERT(original.ticket != NULL);
        TEST_ASSERT(restored.ticket != NULL);
        TEST_ASSERT(memcmp(original.ticket,
                           restored.ticket, original.ticket_len) == 0);
    }
    TEST_ASSERT(original.ticket_lifetime == restored.ticket_lifetime);
#endif

#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
    TEST_ASSERT(original.mfl_code == restored.mfl_code);
#endif

#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
    TEST_ASSERT(original.trunc_hmac == restored.trunc_hmac);
#endif

#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
    TEST_ASSERT(original.encrypt_then_mac == restored.encrypt_then_mac);
#endif

exit:
    mbedtls_ssl_session_free(&original);
    mbedtls_ssl_session_free(&restored);
    mbedtls_free(buf);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_serialize_session_load_save(int ticket_len, char *crt_file)
{
    mbedtls_ssl_session session;
    unsigned char *buf1 = NULL, *buf2 = NULL;
    size_t len0, len1, len2;

    /*
     * Test that a load-save pair is the identity
     */

    mbedtls_ssl_session_init(&session);

    /* Prepare a dummy session to work on */
    TEST_ASSERT(ssl_populate_session(&session, ticket_len, crt_file) == 0);

    /* Get desired buffer size for serializing */
    TEST_ASSERT(mbedtls_ssl_session_save(&session, NULL, 0, &len0)
                == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL);

    /* Allocate first buffer */
    buf1 = mbedtls_calloc(1, len0);
    TEST_ASSERT(buf1 != NULL);

    /* Serialize to buffer and free live session */
    TEST_ASSERT(mbedtls_ssl_session_save(&session, buf1, len0, &len1)
                == 0);
    TEST_ASSERT(len0 == len1);
    mbedtls_ssl_session_free(&session);

    /* Restore session from serialized data */
    TEST_ASSERT(mbedtls_ssl_session_load(&session, buf1, len1) == 0);

    /* Allocate second buffer and serialize to it */
    buf2 = mbedtls_calloc(1, len0);
    TEST_ASSERT(buf2 != NULL);
    TEST_ASSERT(mbedtls_ssl_session_save(&session, buf2, len0, &len2)
                == 0);

    /* Make sure both serialized versions are identical */
    TEST_ASSERT(len1 == len2);
    TEST_ASSERT(memcmp(buf1, buf2, len1) == 0);

exit:
    mbedtls_ssl_session_free(&session);
    mbedtls_free(buf1);
    mbedtls_free(buf2);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_serialize_session_save_buf_size(int ticket_len, char *crt_file)
{
    mbedtls_ssl_session session;
    unsigned char *buf = NULL;
    size_t good_len, bad_len, test_len;

    /*
     * Test that session_save() fails cleanly on small buffers
     */

    mbedtls_ssl_session_init(&session);

    /* Prepare dummy session and get serialized size */
    TEST_ASSERT(ssl_populate_session(&session, ticket_len, crt_file) == 0);
    TEST_ASSERT(mbedtls_ssl_session_save(&session, NULL, 0, &good_len)
                == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL);

    /* Try all possible bad lengths */
    for (bad_len = 1; bad_len < good_len; bad_len++) {
        /* Allocate exact size so that asan/valgrind can detect any overwrite */
        mbedtls_free(buf);
        TEST_ASSERT((buf = mbedtls_calloc(1, bad_len)) != NULL);
        TEST_ASSERT(mbedtls_ssl_session_save(&session, buf, bad_len,
                                             &test_len)
                    == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL);
        TEST_ASSERT(test_len == good_len);
    }

exit:
    mbedtls_ssl_session_free(&session);
    mbedtls_free(buf);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_serialize_session_load_buf_size(int ticket_len, char *crt_file)
{
    mbedtls_ssl_session session;
    unsigned char *good_buf = NULL, *bad_buf = NULL;
    size_t good_len, bad_len;

    /*
     * Test that session_load() fails cleanly on small buffers
     */

    mbedtls_ssl_session_init(&session);

    /* Prepare serialized session data */
    TEST_ASSERT(ssl_populate_session(&session, ticket_len, crt_file) == 0);
    TEST_ASSERT(mbedtls_ssl_session_save(&session, NULL, 0, &good_len)
                == MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL);
    TEST_ASSERT((good_buf = mbedtls_calloc(1, good_len)) != NULL);
    TEST_ASSERT(mbedtls_ssl_session_save(&session, good_buf, good_len,
                                         &good_len) == 0);
    mbedtls_ssl_session_free(&session);

    /* Try all possible bad lengths */
    for (bad_len = 0; bad_len < good_len; bad_len++) {
        /* Allocate exact size so that asan/valgrind can detect any overread */
        mbedtls_free(bad_buf);
        bad_buf = mbedtls_calloc(1, bad_len ? bad_len : 1);
        TEST_ASSERT(bad_buf != NULL);
        memcpy(bad_buf, good_buf, bad_len);

        TEST_ASSERT(mbedtls_ssl_session_load(&session, bad_buf, bad_len)
                    == MBEDTLS_ERR_SSL_BAD_INPUT_DATA);
    }

exit:
    mbedtls_ssl_session_free(&session);
    mbedtls_free(good_buf);
    mbedtls_free(bad_buf);
}
/* END_CASE */

/* BEGIN_CASE */
void ssl_session_serialize_version_check(int corrupt_major,
                                         int corrupt_minor,
                                         int corrupt_patch,
                                         int corrupt_config)
{
    unsigned char serialized_session[2048];
    size_t serialized_session_len;
    unsigned cur_byte;
    mbedtls_ssl_session session;
    uint8_t should_corrupt_byte[] = { corrupt_major  == 1,
                                      corrupt_minor  == 1,
                                      corrupt_patch  == 1,
                                      corrupt_config == 1,
                                      corrupt_config == 1 };

    mbedtls_ssl_session_init(&session);

    /* Infer length of serialized session. */
    TEST_ASSERT(mbedtls_ssl_session_save(&session,
                                         serialized_session,
                                         sizeof(serialized_session),
                                         &serialized_session_len) == 0);

    mbedtls_ssl_session_free(&session);

    /* Without any modification, we should be able to successfully
     * de-serialize the session - double-check that. */
    TEST_ASSERT(mbedtls_ssl_session_load(&session,
                                         serialized_session,
                                         serialized_session_len) == 0);
    mbedtls_ssl_session_free(&session);

    /* Go through the bytes in the serialized session header and
     * corrupt them bit-by-bit. */
    for (cur_byte = 0; cur_byte < sizeof(should_corrupt_byte); cur_byte++) {
        int cur_bit;
        unsigned char * const byte = &serialized_session[cur_byte];

        if (should_corrupt_byte[cur_byte] == 0) {
            continue;
        }

        for (cur_bit = 0; cur_bit < CHAR_BIT; cur_bit++) {
            unsigned char const corrupted_bit = 0x1u << cur_bit;
            /* Modify a single bit in the serialized session. */
            *byte ^= corrupted_bit;

            /* Attempt to deserialize */
            TEST_ASSERT(mbedtls_ssl_session_load(&session,
                                                 serialized_session,
                                                 serialized_session_len) ==
                        MBEDTLS_ERR_SSL_VERSION_MISMATCH);

            /* Undo the change */
            *byte ^= corrupted_bit;
        }
    }

}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_ENTROPY_C:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C */
void mbedtls_endpoint_sanity(int endpoint_type)
{
    enum { BUFFSIZE = 1024 };
    mbedtls_endpoint ep;
    int ret = -1;

    ret = mbedtls_endpoint_init(NULL, endpoint_type, MBEDTLS_PK_RSA,
                                NULL, NULL, NULL, NULL);
    TEST_ASSERT(MBEDTLS_ERR_SSL_BAD_INPUT_DATA == ret);

    ret = mbedtls_endpoint_certificate_init(NULL, MBEDTLS_PK_RSA);
    TEST_ASSERT(MBEDTLS_ERR_SSL_BAD_INPUT_DATA == ret);

    ret = mbedtls_endpoint_init(&ep, endpoint_type, MBEDTLS_PK_RSA,
                                NULL, NULL, NULL, NULL);
    TEST_ASSERT(ret == 0);

exit:
    mbedtls_endpoint_free(&ep, NULL);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_ENTROPY_C:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_ECP_C:MBEDTLS_SHA256_C */
void move_handshake_to_state(int endpoint_type, int state, int need_pass)
{
    enum { BUFFSIZE = 1024 };
    mbedtls_endpoint base_ep, second_ep;
    int ret = -1;

    mbedtls_platform_zeroize(&base_ep, sizeof(base_ep));
    mbedtls_platform_zeroize(&second_ep, sizeof(second_ep));

    ret = mbedtls_endpoint_init(&base_ep, endpoint_type, MBEDTLS_PK_RSA,
                                NULL, NULL, NULL, NULL);
    TEST_ASSERT(ret == 0);

    ret = mbedtls_endpoint_init(&second_ep,
                                (endpoint_type == MBEDTLS_SSL_IS_SERVER) ?
                                MBEDTLS_SSL_IS_CLIENT : MBEDTLS_SSL_IS_SERVER,
                                MBEDTLS_PK_RSA, NULL, NULL, NULL, NULL);
    TEST_ASSERT(ret == 0);

    ret = mbedtls_mock_socket_connect(&(base_ep.socket),
                                      &(second_ep.socket),
                                      BUFFSIZE);
    TEST_ASSERT(ret == 0);

    ret = mbedtls_move_handshake_to_state(&(base_ep.ssl),
                                          &(second_ep.ssl),
                                          state);
    if (need_pass) {
        TEST_ASSERT(ret == 0);
        TEST_ASSERT(base_ep.ssl.state == state);
    } else {
        TEST_ASSERT(ret != 0);
        TEST_ASSERT(base_ep.ssl.state != state);
    }

exit:
    mbedtls_endpoint_free(&base_ep, NULL);
    mbedtls_endpoint_free(&second_ep, NULL);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_ECP_C:MBEDTLS_SHA256_C:MBEDTLS_CAN_HANDLE_RSA_TEST_KEY */
void handshake_version(int dtls, int client_min_version, int client_max_version,
                       int server_min_version, int server_max_version,
                       int expected_negotiated_version)
{
    handshake_test_options options;
    init_handshake_options(&options);

    options.client_min_version = client_min_version;
    options.client_max_version = client_max_version;
    options.server_min_version = server_min_version;
    options.server_max_version = server_max_version;

    options.expected_negotiated_version = expected_negotiated_version;

    options.dtls = dtls;
    /* By default, SSLv3.0 and TLSv1.0 use 1/n-1 splitting when sending data, so
     * the number of fragments will be twice as big. */
    if (expected_negotiated_version == MBEDTLS_SSL_MINOR_VERSION_0 ||
        expected_negotiated_version == MBEDTLS_SSL_MINOR_VERSION_1) {
        options.expected_cli_fragments = 2;
        options.expected_srv_fragments = 2;
    }
    perform_handshake(&options);

    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C */
void handshake_psk_cipher(char *cipher, int pk_alg, data_t *psk_str, int dtls)
{
    handshake_test_options options;
    init_handshake_options(&options);

    options.cipher = cipher;
    options.dtls = dtls;
    options.psk_str = psk_str;
    options.pk_alg = pk_alg;

    perform_handshake(&options);

    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C */
void handshake_cipher(char *cipher, int pk_alg, int dtls)
{
    test_handshake_psk_cipher(cipher, pk_alg, NULL, dtls);

    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C */
void app_data(int mfl, int cli_msg_len, int srv_msg_len,
              int expected_cli_fragments,
              int expected_srv_fragments, int dtls)
{
    handshake_test_options options;
    init_handshake_options(&options);

    options.mfl = mfl;
    options.cli_msg_len = cli_msg_len;
    options.srv_msg_len = srv_msg_len;
    options.expected_cli_fragments = expected_cli_fragments;
    options.expected_srv_fragments = expected_srv_fragments;
    options.dtls = dtls;

    perform_handshake(&options);
    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_ECP_C:MBEDTLS_SHA256_C:MBEDTLS_CAN_HANDLE_RSA_TEST_KEY */
void app_data_tls(int mfl, int cli_msg_len, int srv_msg_len,
                  int expected_cli_fragments,
                  int expected_srv_fragments)
{
    test_app_data(mfl, cli_msg_len, srv_msg_len, expected_cli_fragments,
                  expected_srv_fragments, 0);
    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_SSL_PROTO_DTLS:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C:MBEDTLS_CAN_HANDLE_RSA_TEST_KEY */
void app_data_dtls(int mfl, int cli_msg_len, int srv_msg_len,
                   int expected_cli_fragments,
                   int expected_srv_fragments)
{
    test_app_data(mfl, cli_msg_len, srv_msg_len, expected_cli_fragments,
                  expected_srv_fragments, 1);
    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_SSL_PROTO_DTLS:MBEDTLS_SSL_RENEGOTIATION:MBEDTLS_SSL_CONTEXT_SERIALIZATION:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C:MBEDTLS_CAN_HANDLE_RSA_TEST_KEY */
void handshake_serialization()
{
    handshake_test_options options;
    init_handshake_options(&options);

    options.serialize = 1;
    options.dtls = 1;
    perform_handshake(&options);
    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_DEBUG_C:MBEDTLS_SSL_MAX_FRAGMENT_LENGTH:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C */
void handshake_fragmentation(int mfl,
                             int expected_srv_hs_fragmentation,
                             int expected_cli_hs_fragmentation)
{
    handshake_test_options options;
    log_pattern srv_pattern, cli_pattern;

    srv_pattern.pattern = cli_pattern.pattern = "found fragmented DTLS handshake";
    srv_pattern.counter = 0;
    cli_pattern.counter = 0;

    init_handshake_options(&options);
    options.dtls = 1;
    options.mfl = mfl;
    /* Set cipher to one using CBC so that record splitting can be tested */
    options.cipher = "TLS-DHE-RSA-WITH-AES-256-CBC-SHA256";
    options.srv_auth_mode = MBEDTLS_SSL_VERIFY_REQUIRED;
    options.srv_log_obj = &srv_pattern;
    options.cli_log_obj = &cli_pattern;
    options.srv_log_fun = log_analyzer;
    options.cli_log_fun = log_analyzer;

    perform_handshake(&options);

    /* Test if the server received a fragmented handshake */
    if (expected_srv_hs_fragmentation) {
        TEST_ASSERT(srv_pattern.counter >= 1);
    }
    /* Test if the client received a fragmented handshake */
    if (expected_cli_hs_fragmentation) {
        TEST_ASSERT(cli_pattern.counter >= 1);
    }
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_SSL_PROTO_DTLS:MBEDTLS_SSL_RENEGOTIATION:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C:MBEDTLS_CAN_HANDLE_RSA_TEST_KEY */
void renegotiation(int legacy_renegotiation)
{
    handshake_test_options options;
    init_handshake_options(&options);

    options.renegotiate = 1;
    options.legacy_renegotiation = legacy_renegotiation;
    options.dtls = 1;

    perform_handshake(&options);
    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C */
void resize_buffers(int mfl, int renegotiation, int legacy_renegotiation,
                    int serialize, int dtls, char *cipher)
{
    handshake_test_options options;
    init_handshake_options(&options);

    options.mfl = mfl;
    options.cipher = cipher;
    options.renegotiate = renegotiation;
    options.legacy_renegotiation = legacy_renegotiation;
    options.serialize = serialize;
    options.dtls = dtls;
    options.resize_buffers = 1;

    perform_handshake(&options);
    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH:MBEDTLS_SSL_CONTEXT_SERIALIZATION:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_SSL_PROTO_DTLS:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C:MBEDTLS_CAN_HANDLE_RSA_TEST_KEY */
void resize_buffers_serialize_mfl(int mfl)
{
    test_resize_buffers(mfl, 0, MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION, 1, 1,
                        (char *) "");

    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:!MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_ENTROPY_C:MBEDTLS_CTR_DRBG_C:MBEDTLS_SHA256_C:MBEDTLS_SSL_RENEGOTIATION:MBEDTLS_CAN_HANDLE_RSA_TEST_KEY */
void resize_buffers_renegotiate_mfl(int mfl, int legacy_renegotiation,
                                    char *cipher)
{
    test_resize_buffers(mfl, 1, legacy_renegotiation, 0, 1, cipher);

    /* The goto below is used to avoid an "unused label" warning.*/
    goto exit;
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED:MBEDTLS_USE_PSA_CRYPTO:MBEDTLS_PKCS1_V15:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_ENTROPY_C:MBEDTLS_RSA_C:MBEDTLS_ECP_DP_SECP384R1_ENABLED:MBEDTLS_CTR_DRBG_C:MBEDTLS_ECP_C:MBEDTLS_ECDSA_C */
void raw_key_agreement_fail(int bad_server_ecdhe_key)
{
    enum { BUFFSIZE = 17000 };
    mbedtls_endpoint client, server;
    mbedtls_psa_stats_t stats;
    size_t free_slots_before = -1;

    mbedtls_ecp_group_id curve_list[] = { MBEDTLS_ECP_DP_SECP256R1,
                                          MBEDTLS_ECP_DP_NONE };
    USE_PSA_INIT();
    mbedtls_platform_zeroize(&client, sizeof(client));
    mbedtls_platform_zeroize(&server, sizeof(server));

    /* Client side, force SECP256R1 to make one key bitflip fail
     * the raw key agreement. Flipping the first byte makes the
     * required 0x04 identifier invalid. */
    TEST_EQUAL(mbedtls_endpoint_init(&client, MBEDTLS_SSL_IS_CLIENT,
                                     MBEDTLS_PK_ECDSA, NULL, NULL,
                                     NULL, curve_list), 0);

    /* Server side */
    TEST_EQUAL(mbedtls_endpoint_init(&server, MBEDTLS_SSL_IS_SERVER,
                                     MBEDTLS_PK_ECDSA, NULL, NULL,
                                     NULL, NULL), 0);

    TEST_EQUAL(mbedtls_mock_socket_connect(&(client.socket),
                                           &(server.socket),
                                           BUFFSIZE), 0);

    TEST_EQUAL(mbedtls_move_handshake_to_state(&(client.ssl),
                                               &(server.ssl),
                                               MBEDTLS_SSL_CLIENT_KEY_EXCHANGE)
               , 0);

    mbedtls_psa_get_stats(&stats);
    /* Save the number of slots in use up to this point.
     * With PSA, one can be used for the ECDH private key. */
    free_slots_before = stats.empty_slots;

    if (bad_server_ecdhe_key) {
        /* Force a simulated bitflip in the server key. to make the
         * raw key agreement in ssl_write_client_key_exchange fail. */
        (client.ssl).handshake->ecdh_psa_peerkey[0] ^= 0x02;
    }

    TEST_EQUAL(mbedtls_move_handshake_to_state(&(client.ssl),
                                               &(server.ssl),
                                               MBEDTLS_SSL_HANDSHAKE_OVER),
               bad_server_ecdhe_key ? MBEDTLS_ERR_SSL_HW_ACCEL_FAILED : 0);

    mbedtls_psa_get_stats(&stats);

    /* Make sure that the key slot is already destroyed in case of failure,
     * without waiting to close the connection. */
    if (bad_server_ecdhe_key) {
        TEST_EQUAL(free_slots_before, stats.empty_slots);
    }

exit:
    mbedtls_endpoint_free(&client, NULL);
    mbedtls_endpoint_free(&server, NULL);

    USE_PSA_DONE();
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_SSL_SRV_C:MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE:MBEDTLS_TEST_HOOKS */
void cookie_parsing(data_t *cookie, int exp_ret)
{
    mbedtls_ssl_context ssl;
    mbedtls_ssl_config conf;
    size_t len;

    mbedtls_ssl_init(&ssl);
    mbedtls_ssl_config_init(&conf);
    TEST_EQUAL(mbedtls_ssl_config_defaults(&conf, MBEDTLS_SSL_IS_SERVER,
                                           MBEDTLS_SSL_TRANSPORT_DATAGRAM,
                                           MBEDTLS_SSL_PRESET_DEFAULT),
               0);

    TEST_EQUAL(mbedtls_ssl_setup(&ssl, &conf), 0);
    TEST_EQUAL(mbedtls_ssl_check_dtls_clihlo_cookie(&ssl, ssl.cli_id,
                                                    ssl.cli_id_len,
                                                    cookie->x, cookie->len,
                                                    ssl.out_buf,
                                                    MBEDTLS_SSL_OUT_CONTENT_LEN,
                                                    &len),
               exp_ret);

    mbedtls_ssl_free(&ssl);
    mbedtls_ssl_config_free(&conf);
}
/* END_CASE */