return( MBEDTLS_ERR_SSL_INVALID_RECORD );
}
- /* Check length against bounds of the current transform and version */
- if( ssl->transform_in == NULL )
- {
- if( ssl->in_msglen < 1 ||
- ssl->in_msglen > MBEDTLS_SSL_MAX_CONTENT_LEN )
- {
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
- return( MBEDTLS_ERR_SSL_INVALID_RECORD );
- }
- }
- else
- {
- if( ssl->in_msglen < ssl->transform_in->minlen )
- {
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
- return( MBEDTLS_ERR_SSL_INVALID_RECORD );
- }
-
-#if defined(MBEDTLS_SSL_PROTO_SSL3)
- if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 &&
- ssl->in_msglen > ssl->transform_in->minlen + MBEDTLS_SSL_MAX_CONTENT_LEN )
- {
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
- return( MBEDTLS_ERR_SSL_INVALID_RECORD );
- }
-#endif
-#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
- defined(MBEDTLS_SSL_PROTO_TLS1_2)
- /*
- * TLS encrypted messages can have up to 256 bytes of padding
- */
- if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 &&
- ssl->in_msglen > ssl->transform_in->minlen +
- MBEDTLS_SSL_MAX_CONTENT_LEN + 256 )
- {
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
- return( MBEDTLS_ERR_SSL_INVALID_RECORD );
- }
-#endif
- }
-
/*
- * DTLS-related tests done last, because most of them may result in
- * silently dropping the record (but not the whole datagram), and we only
- * want to consider that after ensuring that the "basic" fields (type,
- * version, length) are sane.
+ * DTLS-related tests.
+ * Check epoch before checking length constraint because
+ * the latter varies with the epoch. E.g., if a ChangeCipherSpec
+ * message gets duplicated before the corresponding Finished message,
+ * the second ChangeCipherSpec should be discarded because it belongs
+ * to an old epoch, but not because its length is shorter than
+ * the minimum record length for packets using the new record transform.
+ * Note that these two kinds of failures are handled differently,
+ * as an unexpected record is silently skipped but an invalid
+ * record leads to the entire datagram being dropped.
*/
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
{
unsigned int rec_epoch = ( ssl->in_ctr[0] << 8 ) | ssl->in_ctr[1];
- /* Drop unexpected ChangeCipherSpec messages */
- if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC &&
- ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC &&
- ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC )
- {
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ChangeCipherSpec" ) );
- return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
- }
-
- /* Drop unexpected ApplicationData records,
- * except at the beginning of renegotiations */
- if( ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA &&
- ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER
-#if defined(MBEDTLS_SSL_RENEGOTIATION)
- && ! ( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
- ssl->state == MBEDTLS_SSL_SERVER_HELLO )
-#endif
- )
- {
- MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ApplicationData" ) );
- return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
- }
-
/* Check epoch (and sequence number) with DTLS */
if( rec_epoch != ssl->in_epoch )
{
return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
}
#endif
+
+ /* Drop unexpected ChangeCipherSpec messages */
+ if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC &&
+ ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC &&
+ ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ChangeCipherSpec" ) );
+ return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
+ }
+
+ /* Drop unexpected ApplicationData records,
+ * except at the beginning of renegotiations */
+ if( ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA &&
+ ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER
+#if defined(MBEDTLS_SSL_RENEGOTIATION)
+ && ! ( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
+ ssl->state == MBEDTLS_SSL_SERVER_HELLO )
+#endif
+ )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ApplicationData" ) );
+ return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
+ }
}
#endif /* MBEDTLS_SSL_PROTO_DTLS */
+
+ /* Check length against bounds of the current transform and version */
+ if( ssl->transform_in == NULL )
+ {
+ if( ssl->in_msglen < 1 ||
+ ssl->in_msglen > MBEDTLS_SSL_MAX_CONTENT_LEN )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
+ return( MBEDTLS_ERR_SSL_INVALID_RECORD );
+ }
+ }
+ else
+ {
+ if( ssl->in_msglen < ssl->transform_in->minlen )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
+ return( MBEDTLS_ERR_SSL_INVALID_RECORD );
+ }
+
+#if defined(MBEDTLS_SSL_PROTO_SSL3)
+ if( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 &&
+ ssl->in_msglen > ssl->transform_in->minlen + MBEDTLS_SSL_MAX_CONTENT_LEN )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
+ return( MBEDTLS_ERR_SSL_INVALID_RECORD );
+ }
+#endif
+#if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
+ defined(MBEDTLS_SSL_PROTO_TLS1_2)
+ /*
+ * TLS encrypted messages can have up to 256 bytes of padding
+ */
+ if( ssl->minor_ver >= MBEDTLS_SSL_MINOR_VERSION_1 &&
+ ssl->in_msglen > ssl->transform_in->minlen +
+ MBEDTLS_SSL_MAX_CONTENT_LEN + 256 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad message length" ) );
+ return( MBEDTLS_ERR_SSL_INVALID_RECORD );
+ }
+#endif
+ }
+
return( 0 );
}
projects / reactos.git / blobdiff