diff --git a/tests/include/test/ssl_helpers.h b/tests/include/test/ssl_helpers.h
index 0209f47..a292def 100644
--- a/tests/include/test/ssl_helpers.h
+++ b/tests/include/test/ssl_helpers.h
@@ -24,5 +24,122 @@
 #define SSL_HELPERS_H
 
 #include <test/helpers.h>
+#include <mbedtls/ssl.h>
+
+#if defined(MBEDTLS_SSL_CACHE_C)
+#include "mbedtls/ssl_cache.h"
+#endif
+
+typedef struct mbedtls_test_ssl_log_pattern {
+    const char *pattern;
+    size_t counter;
+} mbedtls_test_ssl_log_pattern;
+
+typedef struct mbedtls_test_handshake_test_options {
+    const char *cipher;
+    mbedtls_ssl_protocol_version client_min_version;
+    mbedtls_ssl_protocol_version client_max_version;
+    mbedtls_ssl_protocol_version server_min_version;
+    mbedtls_ssl_protocol_version server_max_version;
+    mbedtls_ssl_protocol_version expected_negotiated_version;
+    int expected_handshake_result;
+    int expected_ciphersuite;
+    int pk_alg;
+    int opaque_alg;
+    int opaque_alg2;
+    int opaque_usage;
+    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;
+#if defined(MBEDTLS_SSL_CACHE_C)
+    mbedtls_ssl_cache_context *cache;
+#endif
+} mbedtls_test_handshake_test_options;
+
+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_SSL_HANDSHAKE_WITH_CERT_ENABLED)
+
+/*
+ * 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_test_mock_socket socket;
+    mbedtls_test_ssl_endpoint_certificate cert;
+} mbedtls_test_ssl_endpoint;
+
+#endif /* MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */
 
 #endif /* SSL_HELPERS_H */