From 2c98db24785cb5683b8f63d5fae5a5793cb47d28 Mon Sep 17 00:00:00 2001 From: Hanno Becker Date: Wed, 22 Aug 2018 16:05:47 +0100 Subject: [PATCH] ssl_write_handshake_msg(): Allow alert on client-side SSLv3 In SSLv3, the client sends a NoCertificate alert in response to a CertificateRequest if it doesn't have a CRT. This previously lead to failure in ssl_write_handshake_msg() which only accepted handshake or CCS records. --- library/ssl_tls.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/library/ssl_tls.c b/library/ssl_tls.c index 533e8490a..e54bb0e50 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -3146,11 +3146,19 @@ int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl ) /* * Sanity checks */ - if( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE && + if( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE && ssl->out_msgtype != MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC ) { - MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); - return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); + /* In SSLv3, the client might send a NoCertificate alert. */ +#if defined(MBEDTLS_SSL_PROTO_SSL3) && defined(MBEDTLS_SSL_CLI_C) + if( ! ( ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 && + ssl->out_msgtype == MBEDTLS_SSL_MSG_ALERT && + ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT ) ) +#endif /* MBEDTLS_SSL_PROTO_SSL3 && MBEDTLS_SSL_SRV_C */ + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) ); + return( MBEDTLS_ERR_SSL_INTERNAL_ERROR ); + } } if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&