diff --git a/tests/include/test/ssl_helpers.h b/tests/include/test/ssl_helpers.h
index 0209f47..30a9823 100644
--- a/tests/include/test/ssl_helpers.h
+++ b/tests/include/test/ssl_helpers.h
@@ -25,4 +25,124 @@
 
 #include <test/helpers.h>
 
+#include <mbedtls/ssl.h>
+#include <mbedtls/ctr_drbg.h>
+#include <mbedtls/entropy.h>
+
+typedef struct mbedtls_test_ssl_log_pattern {
+    const char *pattern;
+    size_t counter;
+} mbedtls_test_ssl_log_pattern;
+
+/* 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 mbedtls_test_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;
+} mbedtls_test_handshake_test_options;
+
+/*
+ * Buffer structure for custom I/O callbacks.
+ */
+typedef struct mbedtls_test_ssl_buffer {
+    size_t start;
+    size_t content_length;
+    size_t capacity;
+    unsigned char *buffer;
+} mbedtls_test_ssl_buffer;
+
+/*
+ * Context for a message metadata queue (fifo) that is on top of the ring buffer.
+ */
+typedef struct mbedtls_test_ssl_message_queue {
+    size_t *messages;
+    int pos;
+    int num;
+    int capacity;
+} mbedtls_test_ssl_message_queue;
+
+/*
+ * Context for the I/O callbacks simulating network connection.
+ */
+
+#define MBEDTLS_MOCK_SOCKET_CONNECTED 1
+
+typedef struct mbedtls_test_mock_socket {
+    int status;
+    mbedtls_test_ssl_buffer *input;
+    mbedtls_test_ssl_buffer *output;
+    struct mbedtls_test_mock_socket *peer;
+} mbedtls_test_mock_socket;
+
+/* 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_ssl_message_queue *queue_input;
+    mbedtls_test_ssl_message_queue *queue_output;
+    mbedtls_test_mock_socket *socket;
+} mbedtls_test_message_socket_context;
+
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) && \
+    defined(MBEDTLS_CERTS_C) && \
+    defined(MBEDTLS_ENTROPY_C) && \
+    defined(MBEDTLS_CTR_DRBG_C)
+
+/*
+ * Structure with endpoint's certificates for SSL communication tests.
+ */
+typedef struct mbedtls_test_ssl_endpoint_certificate {
+    mbedtls_x509_crt *ca_cert;
+    mbedtls_x509_crt *cert;
+    mbedtls_pk_context *pkey;
+} mbedtls_test_ssl_endpoint_certificate;
+
+/*
+ * Endpoint structure for SSL communication tests.
+ */
+typedef struct mbedtls_test_ssl_endpoint {
+    const char *name;
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_config conf;
+    mbedtls_ctr_drbg_context ctr_drbg;
+    mbedtls_entropy_context entropy;
+    mbedtls_test_mock_socket socket;
+    mbedtls_test_ssl_endpoint_certificate cert;
+} mbedtls_test_ssl_endpoint;
+
+#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED && MBEDTLS_CERTS_C &&
+          MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
+
 #endif /* SSL_HELPERS_H */