diff options
Diffstat (limited to 'library/ssl_tls13_generic.c')
| -rw-r--r-- | library/ssl_tls13_generic.c | 56 |
1 files changed, 55 insertions, 1 deletions
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c index 064f616..d448a05 100644 --- a/library/ssl_tls13_generic.c +++ b/library/ssl_tls13_generic.c @@ -1379,6 +1379,12 @@ int mbedtls_ssl_tls13_write_change_cipher_spec(mbedtls_ssl_context *ssl) MBEDTLS_SSL_DEBUG_MSG(2, ("=> write change cipher spec")); + /* Only one CCS to send. */ + if (ssl->handshake->ccs_sent) { + ret = 0; + goto cleanup; + } + /* Write CCS message */ MBEDTLS_SSL_PROC_CHK(ssl_tls13_write_change_cipher_spec_body( ssl, ssl->out_msg, @@ -1390,7 +1396,7 @@ int mbedtls_ssl_tls13_write_change_cipher_spec(mbedtls_ssl_context *ssl) /* Dispatch message */ MBEDTLS_SSL_PROC_CHK(mbedtls_ssl_write_record(ssl, 0)); - ssl->handshake->ccs_count++; + ssl->handshake->ccs_sent = 1; cleanup: @@ -1448,6 +1454,54 @@ int mbedtls_ssl_tls13_write_early_data_ext(mbedtls_ssl_context *ssl, return 0; } + +#if defined(MBEDTLS_SSL_SRV_C) +int mbedtls_ssl_tls13_check_early_data_len(mbedtls_ssl_context *ssl, + size_t early_data_len) +{ + /* + * This function should be called only while an handshake is in progress + * and thus a session under negotiation. Add a sanity check to detect a + * misuse. + */ + if (ssl->session_negotiate == NULL) { + return MBEDTLS_ERR_SSL_INTERNAL_ERROR; + } + + /* RFC 8446 section 4.6.1 + * + * A server receiving more than max_early_data_size bytes of 0-RTT data + * SHOULD terminate the connection with an "unexpected_message" alert. + * Note that if it is still possible to send early_data_len bytes of early + * data, it means that early_data_len is smaller than max_early_data_size + * (type uint32_t) and can fit in an uint32_t. We use this further + * down. + */ + if (early_data_len > + (ssl->session_negotiate->max_early_data_size - + ssl->total_early_data_size)) { + + MBEDTLS_SSL_DEBUG_MSG( + 2, ("EarlyData: Too much early data received, %u + %" MBEDTLS_PRINTF_SIZET " > %u", + ssl->total_early_data_size, early_data_len, + ssl->session_negotiate->max_early_data_size)); + + MBEDTLS_SSL_PEND_FATAL_ALERT( + MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE, + MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE); + return MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE; + } + + /* + * early_data_len has been checked to be less than max_early_data_size + * that is uint32_t. Its cast to an uint32_t below is thus safe. We need + * the cast to appease some compilers. + */ + ssl->total_early_data_size += (uint32_t) early_data_len; + + return 0; +} +#endif /* MBEDTLS_SSL_SRV_C */ #endif /* MBEDTLS_SSL_EARLY_DATA */ /* Reset SSL context and update hash for handling HRR. |