update based on comments.
Signed-off-by: Xiaofei Bai <xiaofei.bai@arm.com>
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 83ee98f..23b0670 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1398,6 +1398,272 @@
return( 0 );
}
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+static int ssl_tls13_parse_signature_algorithms_ext( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ const unsigned char *end )
+{
+ size_t sig_alg_list_size; /* size of receive signature algorithms list */
+ const unsigned char *p; /* pointer to individual signature algorithm */
+ const uint16_t *sig_alg; /* iterate through configured signature schemes */
+ unsigned int signature_scheme; /* store received signature algorithm scheme */
+ uint32_t common_idx = 0; /* iterate through received_signature_schemes_list */
+ size_t buf_len = end - buf;
+
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( buf, end, 2 );
+
+ sig_alg_list_size = MBEDTLS_GET_UINT16_BE( buf, 0 );
+ if( sig_alg_list_size + 2 != buf_len ||
+ sig_alg_list_size % 2 != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad signature_algorithms extension" ) );
+ return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+ }
+ memset( ssl->handshake->recv_sig_schemes_list, 0,
+ sizeof( ssl->handshake->recv_sig_schemes_list ) );
+
+ for( p = buf + 2; p < end && common_idx + 1 < MBEDTLS_PK_SIGNATURE_MAX_SIZE; p += 2 )
+ {
+ signature_scheme = MBEDTLS_GET_UINT16_BE( p, 0 );
+
+ MBEDTLS_SSL_DEBUG_MSG( 4, ( "received signature algorithm: 0x%x",
+ signature_scheme ) );
+
+ for( sig_alg = ssl->conf->tls13_sig_algs;
+ *sig_alg != MBEDTLS_TLS1_3_SIG_NONE; sig_alg++ )
+ {
+ if( *sig_alg == signature_scheme )
+ {
+ ssl->handshake->recv_sig_schemes_list[common_idx] = signature_scheme;
+ common_idx++;
+ break;
+ }
+ }
+ }
+
+ if( common_idx == 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "no signature algorithm in common" ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
+ MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+ }
+
+ ssl->handshake->recv_sig_schemes_list[common_idx] = MBEDTLS_TLS1_3_SIG_NONE;
+
+ return( 0 );
+}
+#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+
+/*
+ *
+ * STATE HANDLING: CertificateRequest
+ *
+ */
+
+/*
+ * Overview
+ */
+
+/* Coordination:
+ * Deals with the ambiguity of not knowing if a CertificateRequest
+ * will be sent. Returns a negative code on failure, or
+ * - SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST
+ * - SSL_CERTIFICATE_REQUEST_SKIP
+ * indicating if a Certificate Request is expected or not.
+ */
+#define SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST 0
+#define SSL_CERTIFICATE_REQUEST_SKIP 1
+
+/*
+ * Implementation
+ */
+
+static int ssl_tls13_certificate_request_coordinate( mbedtls_ssl_context *ssl )
+{
+ int ret;
+
+ if( mbedtls_ssl_tls13_psk_enabled( ssl ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "<= skip parse certificate request" ) );
+ return( SSL_CERTIFICATE_REQUEST_SKIP );
+ }
+
+ if( ( ret = mbedtls_ssl_read_record( ssl, 0 ) ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
+ return( ret );
+ }
+ ssl->keep_current_message = 1;
+
+ if( ssl->in_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad certificate request message" ) );
+ MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE,
+ MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+ return( MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE );
+ }
+
+ if( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST )
+ {
+ return( SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST );
+ }
+
+ return( SSL_CERTIFICATE_REQUEST_SKIP );
+}
+
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+/*
+ * ssl_tls13_parse_certificate_request()
+ * Parse certificate request
+ * struct {
+ * opaque certificate_request_context<0..2^8-1>;
+ * Extension extensions<2..2^16-1>;
+ * } CertificateRequest;
+ */
+static int ssl_tls13_parse_certificate_request( mbedtls_ssl_context *ssl,
+ const unsigned char *buf,
+ const unsigned char *end )
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ const unsigned char *p = buf;
+ const unsigned char *extensions_end;
+ size_t extensions_len = 0;
+ size_t certificate_request_context_len = 0;
+
+ /* Parse certificate_request_context */
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 1 );
+ certificate_request_context_len = (size_t) p[0];
+ p++;
+
+ /* store context ( if necessary ) */
+ if( certificate_request_context_len > 0 )
+ {
+ MBEDTLS_SSL_DEBUG_BUF( 3, "Certificate Request Context",
+ p, certificate_request_context_len );
+
+ ssl->handshake->certificate_request_context =
+ mbedtls_calloc( certificate_request_context_len, 1 );
+ if( ssl->handshake->certificate_request_context == NULL )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return ( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+ }
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, certificate_request_context_len );
+ memcpy( ssl->handshake->certificate_request_context, p,
+ certificate_request_context_len );
+
+ /* jump over certificate_request_context */
+ p += certificate_request_context_len;
+ }
+
+ /*
+ * Parse extensions
+ */
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
+ extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
+ p += 2;
+
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
+ extensions_end = p + extensions_len;
+
+ while( p < extensions_end )
+ {
+ unsigned int extension_type;
+ size_t extension_data_len;
+
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
+ extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
+ extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
+ p += 4;
+
+ MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
+
+ switch( extension_type )
+ {
+ case MBEDTLS_TLS_EXT_SIG_ALG:
+ MBEDTLS_SSL_DEBUG_MSG( 3,
+ ( "found signature_algorithms extension" ) );
+
+ ret = ssl_tls13_parse_signature_algorithms_ext( ssl, p,
+ p + extension_data_len );
+ if( ret != 0 )
+ return( ret );
+ break;
+
+ default:
+ MBEDTLS_SSL_DEBUG_MSG(
+ 3,
+ ( "unknown extension found: %u ( ignoring )",
+ extension_type ) );
+
+ MBEDTLS_SSL_PEND_FATAL_ALERT(
+ MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT,
+ MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
+ return( MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
+ }
+
+ p += extension_data_len;
+ }
+
+ ssl->client_auth = 1;
+ return( 0 );
+}
+#endif /* ( MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED ) */
+
+/* Main entry point; orchestrates the other functions */
+int mbedtls_ssl_tls13_process_certificate_request( mbedtls_ssl_context *ssl )
+{
+ int ret = 0;
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate request" ) );
+
+ /* Coordination step
+ * - Fetch record
+ * - Make sure it's either a CertificateRequest or a ServerHelloDone
+ */
+ MBEDTLS_SSL_PROC_CHK_NEG( ssl_tls13_certificate_request_coordinate( ssl ) );
+
+#if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+ if( ret == SSL_CERTIFICATE_REQUEST_EXPECT_REQUEST )
+ {
+ unsigned char *buf;
+ size_t buf_len;
+
+ MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_fetch_handshake_msg( ssl,
+ MBEDTLS_SSL_HS_CERTIFICATE_REQUEST,
+ &buf, &buf_len ) );
+
+ MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_certificate_request( ssl,
+ buf, buf + buf_len ) );
+
+ mbedtls_ssl_tls13_add_hs_msg_to_checksum(
+ ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, buf, buf_len );
+ }
+ else
+#endif /* MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
+ if( ret == SSL_CERTIFICATE_REQUEST_SKIP )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate request" ) );
+ }
+ else
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+ }
+
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "got %s certificate request",
+ ssl->client_auth ? "a" : "no" ) );
+
+cleanup:
+
+ /* In the MPS one would close the read-port here to
+ * ensure there's no overlap of reading and writing. */
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate request" ) );
+ return( ret );
+}
+
#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
/*
* Handler for MBEDTLS_SSL_CERTIFICATE_REQUEST
@@ -1412,13 +1678,9 @@
return( ret );
}
- if( ( ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE ) &&
- ( ssl->in_msg[0] == MBEDTLS_SSL_HS_CERTIFICATE_REQUEST ) )
- {
- ret = mbedtls_ssl_tls13_process_certificate_request( ssl );
- if( ret != 0 )
- return( ret );
- }
+ ret = mbedtls_ssl_tls13_process_certificate_request( ssl );
+ if( ret != 0 )
+ return( ret );
ssl->keep_current_message = 1;
mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_CERTIFICATE );