Merge pull request #6791 from yanrayw/6675-change-some-key-generation-funcs-to-static
TLS 1.3: Key Generation: change some key generation functions to static
diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index ecfdab3..b92f12e 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -644,7 +644,24 @@
return 0;
}
-int mbedtls_ssl_tls13_key_schedule_stage_application(mbedtls_ssl_context *ssl)
+/**
+ * \brief Transition into application stage of TLS 1.3 key schedule.
+ *
+ * The TLS 1.3 key schedule can be viewed as a simple state machine
+ * with states Initial -> Early -> Handshake -> Application, and
+ * this function represents the Handshake -> Application transition.
+ *
+ * In the handshake stage, ssl_tls13_generate_application_keys()
+ * can be used to derive the handshake traffic keys.
+ *
+ * \param ssl The SSL context to operate on. This must be in key schedule
+ * stage \c Handshake.
+ *
+ * \returns \c 0 on success.
+ * \returns A negative error code on failure.
+ */
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_key_schedule_stage_application(mbedtls_ssl_context *ssl)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
@@ -1282,10 +1299,25 @@
return 0;
}
-/* mbedtls_ssl_tls13_generate_handshake_keys() generates keys necessary for
- * protecting the handshake messages, as described in Section 7 of TLS 1.3. */
-int mbedtls_ssl_tls13_generate_handshake_keys(mbedtls_ssl_context *ssl,
- mbedtls_ssl_key_set *traffic_keys)
+/**
+ * \brief Compute TLS 1.3 handshake traffic keys.
+ *
+ * ssl_tls13_generate_handshake_keys() generates keys necessary for
+ * protecting the handshake messages, as described in Section 7 of
+ * RFC 8446.
+ *
+ * \param ssl The SSL context to operate on. This must be in
+ * key schedule stage \c Handshake, see
+ * ssl_tls13_key_schedule_stage_handshake().
+ * \param traffic_keys The address at which to store the handshake traffic
+ * keys. This must be writable but may be uninitialized.
+ *
+ * \returns \c 0 on success.
+ * \returns A negative error code on failure.
+ */
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_generate_handshake_keys(mbedtls_ssl_context *ssl,
+ mbedtls_ssl_key_set *traffic_keys)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_md_type_t md_type;
@@ -1300,7 +1332,7 @@
const mbedtls_ssl_ciphersuite_t *ciphersuite_info = handshake->ciphersuite_info;
mbedtls_ssl_tls13_handshake_secrets *tls13_hs_secrets = &handshake->tls13_hs_secrets;
- MBEDTLS_SSL_DEBUG_MSG(2, ("=> mbedtls_ssl_tls13_generate_handshake_keys"));
+ MBEDTLS_SSL_DEBUG_MSG(2, ("=> ssl_tls13_generate_handshake_keys"));
ret = ssl_tls13_get_cipher_key_info(ciphersuite_info, &key_len, &iv_len);
if (ret != 0) {
@@ -1386,14 +1418,31 @@
traffic_keys->server_write_iv,
traffic_keys->iv_len);
- MBEDTLS_SSL_DEBUG_MSG(2, ("<= mbedtls_ssl_tls13_generate_handshake_keys"));
+ MBEDTLS_SSL_DEBUG_MSG(2, ("<= ssl_tls13_generate_handshake_keys"));
exit:
return ret;
}
-int mbedtls_ssl_tls13_key_schedule_stage_handshake(mbedtls_ssl_context *ssl)
+/**
+ * \brief Transition into handshake stage of TLS 1.3 key schedule.
+ *
+ * The TLS 1.3 key schedule can be viewed as a simple state machine
+ * with states Initial -> Early -> Handshake -> Application, and
+ * this function represents the Early -> Handshake transition.
+ *
+ * In the handshake stage, ssl_tls13_generate_handshake_keys()
+ * can be used to derive the handshake traffic keys.
+ *
+ * \param ssl The SSL context to operate on. This must be in key schedule
+ * stage \c Early.
+ *
+ * \returns \c 0 on success.
+ * \returns A negative error code on failure.
+ */
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_key_schedule_stage_handshake(mbedtls_ssl_context *ssl)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
@@ -1479,10 +1528,24 @@
return ret;
}
-/* Generate application traffic keys since any records following a 1-RTT Finished message
- * MUST be encrypted under the application traffic key.
+/**
+ * \brief Compute TLS 1.3 application traffic keys.
+ *
+ * ssl_tls13_generate_application_keys() generates application traffic
+ * keys, since any record following a 1-RTT Finished message MUST be
+ * encrypted under the application traffic key.
+ *
+ * \param ssl The SSL context to operate on. This must be in
+ * key schedule stage \c Application, see
+ * ssl_tls13_key_schedule_stage_application().
+ * \param traffic_keys The address at which to store the application traffic
+ * keys. This must be writable but may be uninitialized.
+ *
+ * \returns \c 0 on success.
+ * \returns A negative error code on failure.
*/
-int mbedtls_ssl_tls13_generate_application_keys(
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_generate_application_keys(
mbedtls_ssl_context *ssl,
mbedtls_ssl_key_set *traffic_keys)
{
@@ -1612,7 +1675,7 @@
mbedtls_ssl_handshake_params *handshake = ssl->handshake;
/* Compute handshake secret */
- ret = mbedtls_ssl_tls13_key_schedule_stage_handshake(ssl);
+ ret = ssl_tls13_key_schedule_stage_handshake(ssl);
if (ret != 0) {
MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_tls13_derive_master_secret", ret);
goto cleanup;
@@ -1620,9 +1683,9 @@
/* Next evolution in key schedule: Establish handshake secret and
* key material. */
- ret = mbedtls_ssl_tls13_generate_handshake_keys(ssl, &traffic_keys);
+ ret = ssl_tls13_generate_handshake_keys(ssl, &traffic_keys);
if (ret != 0) {
- MBEDTLS_SSL_DEBUG_RET(1, "mbedtls_ssl_tls13_generate_handshake_keys",
+ MBEDTLS_SSL_DEBUG_RET(1, "ssl_tls13_generate_handshake_keys",
ret);
goto cleanup;
}
@@ -1702,17 +1765,17 @@
mbedtls_ssl_key_set traffic_keys;
mbedtls_ssl_transform *transform_application = NULL;
- ret = mbedtls_ssl_tls13_key_schedule_stage_application(ssl);
+ ret = ssl_tls13_key_schedule_stage_application(ssl);
if (ret != 0) {
MBEDTLS_SSL_DEBUG_RET(1,
- "mbedtls_ssl_tls13_key_schedule_stage_application", ret);
+ "ssl_tls13_key_schedule_stage_application", ret);
goto cleanup;
}
- ret = mbedtls_ssl_tls13_generate_application_keys(ssl, &traffic_keys);
+ ret = ssl_tls13_generate_application_keys(ssl, &traffic_keys);
if (ret != 0) {
MBEDTLS_SSL_DEBUG_RET(1,
- "mbedtls_ssl_tls13_generate_application_keys", ret);
+ "ssl_tls13_generate_application_keys", ret);
goto cleanup;
}
diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h
index d4f2b40..21e9b4d 100644
--- a/library/ssl_tls13_keys.h
+++ b/library/ssl_tls13_keys.h
@@ -554,76 +554,6 @@
int mbedtls_ssl_tls13_key_schedule_stage_early(mbedtls_ssl_context *ssl);
/**
- * \brief Transition into handshake stage of TLS 1.3 key schedule.
- *
- * The TLS 1.3 key schedule can be viewed as a simple state machine
- * with states Initial -> Early -> Handshake -> Application, and
- * this function represents the Early -> Handshake transition.
- *
- * In the handshake stage, mbedtls_ssl_tls13_generate_handshake_keys()
- * can be used to derive the handshake traffic keys.
- *
- * \param ssl The SSL context to operate on. This must be in key schedule
- * stage \c Early.
- *
- * \returns \c 0 on success.
- * \returns A negative error code on failure.
- */
-MBEDTLS_CHECK_RETURN_CRITICAL
-int mbedtls_ssl_tls13_key_schedule_stage_handshake(mbedtls_ssl_context *ssl);
-
-/**
- * \brief Compute TLS 1.3 handshake traffic keys.
- *
- * \param ssl The SSL context to operate on. This must be in
- * key schedule stage \c Handshake, see
- * mbedtls_ssl_tls13_key_schedule_stage_handshake().
- * \param traffic_keys The address at which to store the handshake traffic key
- * keys. This must be writable but may be uninitialized.
- *
- * \returns \c 0 on success.
- * \returns A negative error code on failure.
- */
-MBEDTLS_CHECK_RETURN_CRITICAL
-int mbedtls_ssl_tls13_generate_handshake_keys(mbedtls_ssl_context *ssl,
- mbedtls_ssl_key_set *traffic_keys);
-
-/**
- * \brief Transition into application stage of TLS 1.3 key schedule.
- *
- * The TLS 1.3 key schedule can be viewed as a simple state machine
- * with states Initial -> Early -> Handshake -> Application, and
- * this function represents the Handshake -> Application transition.
- *
- * In the handshake stage, mbedtls_ssl_tls13_generate_application_keys()
- * can be used to derive the handshake traffic keys.
- *
- * \param ssl The SSL context to operate on. This must be in key schedule
- * stage \c Handshake.
- *
- * \returns \c 0 on success.
- * \returns A negative error code on failure.
- */
-MBEDTLS_CHECK_RETURN_CRITICAL
-int mbedtls_ssl_tls13_key_schedule_stage_application(mbedtls_ssl_context *ssl);
-
-/**
- * \brief Compute TLS 1.3 application traffic keys.
- *
- * \param ssl The SSL context to operate on. This must be in
- * key schedule stage \c Application, see
- * mbedtls_ssl_tls13_key_schedule_stage_application().
- * \param traffic_keys The address at which to store the application traffic key
- * keys. This must be writable but may be uninitialized.
- *
- * \returns \c 0 on success.
- * \returns A negative error code on failure.
- */
-MBEDTLS_CHECK_RETURN_CRITICAL
-int mbedtls_ssl_tls13_generate_application_keys(
- mbedtls_ssl_context *ssl, mbedtls_ssl_key_set *traffic_keys);
-
-/**
* \brief Compute TLS 1.3 resumption master secret.
*
* \param ssl The SSL context to operate on. This must be in