Add write certificate and client handler
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 0656439..4b307c2 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1736,6 +1736,11 @@
int mbedtls_ssl_tls13_process_certificate( mbedtls_ssl_context *ssl );
/*
+ * Handler of TLS 1.3 write certificate message
+ */
+int mbedtls_ssl_tls13_write_certificate( mbedtls_ssl_context *ssl );
+
+/*
* Generic handler of Certificate Verify
*/
int mbedtls_ssl_tls13_process_certificate_verify( mbedtls_ssl_context *ssl );
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index c10b698..f1483c7 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1948,9 +1948,11 @@
*/
static int ssl_tls13_write_client_certificate( mbedtls_ssl_context *ssl )
{
+ MBEDTLS_SSL_DEBUG_MSG( 1,
+ ( "Switch to handshake traffic keys for outbound traffic" ) );
mbedtls_ssl_set_outbound_transform( ssl, ssl->handshake->transform_handshake );
- mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY );
- return( 0 );
+
+ return( mbedtls_ssl_tls13_write_certificate( ssl ) );
}
/*
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 14884aa..513b7c0 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -848,6 +848,196 @@
}
/*
+ * STATE HANDLING: Output Certificate
+ */
+/* Check if a certificate should be written, and if yes,
+ * if it is available.
+ * Returns a negative error code on failure ( such as no certificate
+ * being available on the server ), and otherwise
+ * SSL_WRITE_CERTIFICATE_AVAILABLE or
+ * SSL_WRITE_CERTIFICATE_SKIP
+ * indicating that a Certificate message should be written based
+ * on the configured certificate, or whether it should be silently skipped.
+ */
+#define SSL_WRITE_CERTIFICATE_AVAILABLE 0
+#define SSL_WRITE_CERTIFICATE_SKIP 1
+
+
+static int ssl_tls13_write_certificate_coordinate( mbedtls_ssl_context* ssl )
+{
+
+ /* For PSK and ECDHE-PSK ciphersuites there is no certificate to exchange. */
+ if( mbedtls_ssl_tls13_some_psk_enabled( ssl ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
+ return( SSL_WRITE_CERTIFICATE_SKIP );
+ }
+
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+#if defined(MBEDTLS_SSL_CLI_C)
+ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
+ {
+ /* The client MUST send a Certificate message if and only
+ * if the server has requested client authentication via a
+ * CertificateRequest message.
+ *
+ * client_auth indicates whether the server had requested
+ * client authentication.
+ */
+ if( ssl->handshake->client_auth == 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
+ return( SSL_WRITE_CERTIFICATE_SKIP );
+ }
+ }
+#endif /* MBEDTLS_SSL_CLI_C */
+
+ return( SSL_WRITE_CERTIFICATE_AVAILABLE );
+#else /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+#endif /* !MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
+}
+
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+static int ssl_tls13_write_certificate( mbedtls_ssl_context *ssl,
+ unsigned char *buf,
+ size_t buflen,
+ size_t *olen )
+{
+ size_t i=0, n, total_len;
+ const mbedtls_x509_crt *crt = mbedtls_ssl_own_cert( ssl );
+ unsigned char *start;
+
+ /* TODO: Add bounds checks! Only then remove the next line. */
+ ((void) buflen );
+
+ /* empty certificate_request_context with length 0 */
+ buf[i] = 0;
+ /* Skip length of certificate_request_context and
+ * the length of CertificateEntry
+ */
+ i += 1;
+
+#if defined(MBEDTLS_SSL_CLI_C)
+ /* If the server requests client authentication but no suitable
+ * certificate is available, the client MUST send a
+ * Certificate message containing no certificates
+ * ( i.e., with the "certificate_list" field having length 0 ).
+ *
+ * authmode indicates whether the client configuration required authentication.
+ */
+ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT &&
+ ( ( crt == NULL ) || ssl->conf->authmode == MBEDTLS_SSL_VERIFY_NONE ) )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write empty client certificate" ) );
+ buf[i] = 0;
+ buf[i + 1] = 0;
+ buf[i + 2] = 0;
+ i += 3;
+ *olen = i;
+ return( 0 );
+ }
+#endif /* MBEDTLS_SSL_CLI_C */
+
+ start = &buf[i];
+ MBEDTLS_SSL_DEBUG_CRT( 3, "own certificate", crt );
+
+ i += 3;
+
+ while ( crt != NULL )
+ {
+ n = crt->raw.len;
+ if( n > buflen - 3 - i )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "certificate too large, %" MBEDTLS_PRINTF_SIZET " > %d",
+ i + 3 + n, MBEDTLS_SSL_OUT_CONTENT_LEN ) );
+ return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
+ }
+
+ buf[i] = (unsigned char)( n >> 16 );
+ buf[i + 1] = (unsigned char)( n >> 8 );
+ buf[i + 2] = (unsigned char)( n );
+
+ i += 3; memcpy( buf + i, crt->raw.p, n );
+ i += n; crt = crt->next;
+
+ /* Currently, we don't have any certificate extensions defined.
+ * Hence, we are sending an empty extension with length zero.
+ */
+ buf[i] = 0;
+ buf[i + 1] = 0;
+ i += 2;
+ }
+ total_len = &buf[i] - start - 3;
+ *start++ = (unsigned char)( ( total_len ) >> 16 );
+ *start++ = (unsigned char)( ( total_len ) >> 8 );
+ *start++ = (unsigned char)( ( total_len ) );
+
+ *olen = i;
+
+ return( 0 );
+}
+#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
+
+/* Update the state after handling the outgoing certificate message. */
+static int ssl_tls13_finalize_write_certificate( mbedtls_ssl_context* ssl )
+{
+#if defined(MBEDTLS_SSL_CLI_C)
+ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
+ {
+ mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_CLIENT_CERTIFICATE_VERIFY );
+ return( 0 );
+ }
+ else
+#endif /* MBEDTLS_SSL_CLI_C */
+
+ return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+}
+
+int mbedtls_ssl_tls13_write_certificate( mbedtls_ssl_context* ssl )
+{
+ int ret;
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) );
+
+ /* Coordination: Check if we need to send a certificate. */
+ MBEDTLS_SSL_PROC_CHK_NEG( ssl_tls13_write_certificate_coordinate( ssl ) );
+
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+ if( ret == SSL_WRITE_CERTIFICATE_AVAILABLE )
+ {
+ unsigned char *buf;
+ size_t buf_len, msg_len;
+
+ MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_start_handshake_msg( ssl,
+ MBEDTLS_SSL_HS_CERTIFICATE, &buf, &buf_len ) );
+
+ MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_certificate( ssl, buf, buf_len,
+ &msg_len ) );
+
+ mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl,
+ MBEDTLS_SSL_HS_CERTIFICATE,
+ buf,
+ msg_len );
+
+ MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_write_certificate( ssl ) );
+ MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg(
+ ssl, buf_len, msg_len ) );
+ }
+ else
+#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) );
+ MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_write_certificate( ssl ) );
+ }
+
+cleanup:
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write certificate" ) );
+ return( ret );
+}
+
+/*
*
* STATE HANDLING: Incoming Finished message.
*/