Add some hooks in mbedtls_test_ssl_perform_handshake()

Let test code customize the kitchen sink function
`mbedtls_test_ssl_perform_handshake()` at a few points.

Signed-off-by: Gilles Peskine <[email protected]>

tests/include/test/ssl_helpers.h

@@ -115,6 +115,9 @@ enum {
 #define MBEDTLS_TEST_MAX_ALPN_LIST_SIZE 10
 #endif
 
+/* Forward declaration. Defined below. */
+struct mbedtls_test_ssl_endpoint;
+
 typedef struct mbedtls_test_ssl_log_pattern {
     const char *pattern;
     size_t counter;
@@ -145,6 +148,35 @@ typedef struct mbedtls_test_handshake_test_options {
     int expected_srv_fragments;
     int renegotiate;
     int legacy_renegotiation;
+    /** Hook that mbedtls_test_ssl_perform_handshake() runs just before
+     * the initial handshake. */
+    void (*pre_handshake_fun)(struct mbedtls_test_ssl_endpoint *client,
+                              struct mbedtls_test_ssl_endpoint *server,
+                              void *param);
+    /** Value passed to ::pre_handshake_fun. */
+    void *pre_handshake_param;
+    /** Hook that mbedtls_test_ssl_perform_handshake() runs after
+     * the initial handshake succeeds. */
+    void (*post_handshake_fun)(struct mbedtls_test_ssl_endpoint *client,
+                               struct mbedtls_test_ssl_endpoint *server,
+                               void *param);
+    /** Value passed to ::post_handshake_fun. */
+    void *post_handshake_param;
+    /** Hook that mbedtls_test_ssl_perform_handshake() runs after
+     * exchanging some data, before testing additional features such as
+     * serialization and renegotiation. */
+    void (*post_data_fun)(struct mbedtls_test_ssl_endpoint *client,
+                          struct mbedtls_test_ssl_endpoint *server,
+                          void *param);
+    /** Value passed to ::post_data_fun. */
+    void *post_data_param;
+    /** Hook that mbedtls_test_ssl_perform_handshake() runs after a successful
+     * connection, just before closing down. */
+    void (*pre_shutdown_fun)(struct mbedtls_test_ssl_endpoint *client,
+                             struct mbedtls_test_ssl_endpoint *server,
+                             void *param);
+    /** Value passed to ::pre_shutdown_fun. */
+    void *pre_shutdown_param;
     void *srv_log_obj;
     void *cli_log_obj;
     void (*srv_log_fun)(void *, int, const char *, int, const char *);

tests/src/test_helpers/ssl_helpers.c

@@ -2252,6 +2252,10 @@ void mbedtls_test_ssl_perform_handshake(
         expected_handshake_result = MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION;
     }
 
+    if (options->pre_handshake_fun != NULL) {
+        options->pre_handshake_fun(&client, &server, options->pre_handshake_param);
+    }
+
     TEST_ASSERT(mbedtls_test_move_handshake_to_state(&(client.ssl),
                                                      &(server.ssl),
                                                      MBEDTLS_SSL_HANDSHAKE_OVER)
@@ -2289,6 +2293,10 @@ void mbedtls_test_ssl_perform_handshake(
                    options->expected_ciphersuite);
     }
 
+    if (options->post_handshake_fun != NULL) {
+        options->post_handshake_fun(&client, &server, options->post_handshake_param);
+    }
+
 #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
     if (options->resize_buffers != 0) {
         /* A server, when using DTLS, might delay a buffer resize to happen
@@ -2315,6 +2323,11 @@ void mbedtls_test_ssl_perform_handshake(
                         options->expected_srv_fragments)
                     == 0);
     }
+
+    if (options->post_data_fun != NULL) {
+        options->post_data_fun(&client, &server, options->post_data_param);
+    }
+
 #if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
     if (options->serialize == 1) {
         TEST_ASSERT(options->dtls == 1);
@@ -2449,6 +2462,10 @@ void mbedtls_test_ssl_perform_handshake(
     TEST_ASSERT(mbedtls_ssl_conf_get_user_data_p(&server.conf) == &server);
     TEST_ASSERT(mbedtls_ssl_get_user_data_p(&server.ssl) == &server);
 
+    if (options->pre_shutdown_fun != NULL) {
+        options->pre_shutdown_fun(&client, &server, options->pre_shutdown_param);
+    }
+
 exit:
     mbedtls_test_ssl_endpoint_free(&client,
                                    options->dtls != 0 ? &client_context : NULL);