diff --git a/tests/include/test/ssl_helpers.h b/tests/include/test/ssl_helpers.h
index 30a9823..7141a84 100644
--- a/tests/include/test/ssl_helpers.h
+++ b/tests/include/test/ssl_helpers.h
@@ -23,11 +23,25 @@
 #ifndef SSL_HELPERS_H
 #define SSL_HELPERS_H
 
-#include <test/helpers.h>
+#include <string.h>
 
-#include <mbedtls/ssl.h>
+#include <test/helpers.h>
+#include <test/macros.h>
+#include <test/random.h>
+#include <test/psa_crypto_helpers.h>
+
+#if defined(MBEDTLS_SSL_TLS_C)
+#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>
+
+#if defined(MBEDTLS_SSL_CACHE_C)
+#include "mbedtls/ssl_cache.h"
+#endif
 
 typedef struct mbedtls_test_ssl_log_pattern {
     const char *pattern;
@@ -145,4 +159,325 @@
 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && MBEDTLS_CERTS_C &&
           MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
 
+/*
+ * This function can be passed to mbedtls to receive output logs from it. In
+ * this case, it will count the instances of a mbedtls_test_ssl_log_pattern
+ * in the received logged messages.
+ */
+void mbedtls_test_ssl_log_analyzer(void *ctx, int level,
+                                   const char *file, int line,
+                                   const char *str);
+
+void mbedtls_test_init_handshake_options(
+    mbedtls_test_handshake_test_options *opts);
+
+/*
+ * Initialises \p buf. After calling this function it is safe to call
+ * `mbedtls_test_ssl_buffer_free()` on \p buf.
+ */
+void mbedtls_test_ssl_buffer_init(mbedtls_test_ssl_buffer *buf);
+
+/*
+ * Sets up \p buf. After calling this function it is safe to call
+ * `mbedtls_test_ssl_buffer_put()` and `mbedtls_test_ssl_buffer_get()`
+ * on \p buf.
+ */
+int mbedtls_test_ssl_buffer_setup(mbedtls_test_ssl_buffer *buf,
+                                  size_t capacity);
+
+void mbedtls_test_ssl_buffer_free(mbedtls_test_ssl_buffer *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_ssl_buffer_init()` and `mbedtls_test_ssl_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_ssl_buffer_put(mbedtls_test_ssl_buffer *buf,
+                                const unsigned char *input, size_t 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_ssl_buffer_init()` and `mbedtls_test_ssl_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_ssl_buffer_get(mbedtls_test_ssl_buffer *buf,
+                                unsigned char *output, size_t output_len);
+
+/*
+ * Errors used in the message transport mock tests
+ */
+ #define MBEDTLS_TEST_ERROR_ARG_NULL -11
+ #define MBEDTLS_TEST_ERROR_MESSAGE_TRUNCATED -44
+
+/*
+ * 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_ssl_message_queue_setup(
+    mbedtls_test_ssl_message_queue *queue, size_t capacity);
+
+void mbedtls_test_ssl_message_queue_free(
+    mbedtls_test_ssl_message_queue *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_ssl_message_queue_push_info(
+    mbedtls_test_ssl_message_queue *queue, size_t 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_ssl_message_queue_pop_info(
+    mbedtls_test_ssl_message_queue *queue, size_t buf_len);
+
+/*
+ * Setup and teardown functions for mock sockets.
+ */
+void mbedtls_mock_socket_init(mbedtls_test_mock_socket *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_test_mock_socket_close(mbedtls_test_mock_socket *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_test_mock_socket_connect(mbedtls_test_mock_socket *peer1,
+                                     mbedtls_test_mock_socket *peer2,
+                                     size_t bufsize);
+
+/*
+ * Callbacks for simulating blocking I/O over connection-oriented transport.
+ */
+int mbedtls_test_mock_tcp_send_b(void *ctx,
+                                 const unsigned char *buf, size_t len);
+
+int mbedtls_test_mock_tcp_recv_b(void *ctx, unsigned char *buf, size_t len);
+
+/*
+ * Callbacks for simulating non-blocking I/O over connection-oriented transport.
+ */
+int mbedtls_test_mock_tcp_send_nb(void *ctx,
+                                  const unsigned char *buf, size_t len);
+
+int mbedtls_test_mock_tcp_recv_nb(void *ctx, unsigned char *buf, size_t len);
+
+void mbedtls_test_message_socket_init(
+    mbedtls_test_message_socket_context *ctx);
+
+/*
+ * 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_test_message_socket_setup(
+    mbedtls_test_ssl_message_queue *queue_input,
+    mbedtls_test_ssl_message_queue *queue_output,
+    size_t queue_capacity,
+    mbedtls_test_mock_socket *socket,
+    mbedtls_test_message_socket_context *ctx);
+
+/*
+ * Close a given message socket context, along with the socket itself. Free the
+ * memory allocated by the input queue.
+ */
+void mbedtls_test_message_socket_close(
+    mbedtls_test_message_socket_context *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_test_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_ssl_message_queue_push_info.
+ */
+int mbedtls_test_mock_tcp_send_msg(void *ctx,
+                                   const unsigned char *buf, size_t 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_test_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_test_mock_tcp_recv_msg(void *ctx,
+                                   unsigned char *buf, size_t buf_len);
+
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) && \
+    defined(MBEDTLS_CERTS_C) && \
+    defined(MBEDTLS_ENTROPY_C) && \
+    defined(MBEDTLS_CTR_DRBG_C)
+
+/*
+ * Initializes \p ep_cert structure and assigns it to endpoint
+ * represented by \p ep.
+ *
+ * \retval  0 on success, otherwise error code.
+ */
+int mbedtls_test_ssl_endpoint_certificate_init(mbedtls_test_ssl_endpoint *ep,
+                                               int pk_alg);
+
+/*
+ * Initializes \p ep structure. It is important to call
+ * `mbedtls_test_ssl_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_test_ssl_endpoint_init(
+    mbedtls_test_ssl_endpoint *ep, int endpoint_type, int pk_alg,
+    mbedtls_test_message_socket_context *dtls_context,
+    mbedtls_test_ssl_message_queue *input_queue,
+    mbedtls_test_ssl_message_queue *output_queue,
+    const mbedtls_ecp_group_id *curves);
+
+/*
+ * Deinitializes endpoint represented by \p ep.
+ */
+void mbedtls_test_ssl_endpoint_free(
+    mbedtls_test_ssl_endpoint *ep,
+    mbedtls_test_message_socket_context *context);
+
+/*
+ * 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_test_move_handshake_to_state(mbedtls_ssl_context *ssl,
+                                         mbedtls_ssl_context *second_ssl,
+                                         int state);
+
+#endif \
+    /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && MBEDTLS_CERTS_C &&
+       MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
+
+int mbedtls_test_ssl_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);
+
+/*
+ * Populate a session structure for serialization tests.
+ * Choose dummy values, mostly non-0 to distinguish from the init default.
+ */
+int mbedtls_test_ssl_populate_session(mbedtls_ssl_session *session,
+                                      int ticket_len,
+                                      const char *crt_file);
+
+/*
+ * 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);
+
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) && \
+    defined(MBEDTLS_CERTS_C) && \
+    defined(MBEDTLS_ENTROPY_C) && \
+    defined(MBEDTLS_CTR_DRBG_C)
+void mbedtls_test_ssl_perform_handshake(
+    mbedtls_test_handshake_test_options *options);
+#endif \
+    /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && MBEDTLS_CERTS_C && MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
+#endif /* MBEDTLS_SSL_TLS_C */
+
 #endif /* SSL_HELPERS_H */