Fix incomplete assertion in ssl_write_handshake_msg()
ssl_write_handshake_msg() includes the assertion that
`ssl->handshake != NULL` when handling a record which is
(a) a handshake message, and NOT
(b) a HelloRequest.
However, it later calls `ssl_append_flight()` for any
record different from a HelloRequest handshake record,
that is, records satisfying !(a) || !(b), instead of
(a) && !(b) as covered by the assertion (specifically,
CCS or Alert records).
Since `ssl_append_flight()` assumes that `ssl->handshake != NULL`,
this rightfully triggers static analyzer warnings.
This commit expands the scope of the assertion to check
that `ssl->handshake != NULL` for any record which is not
a HelloRequest.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 82e6525..4dd2910 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3200,8 +3200,10 @@
}
}
- if( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
- hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST &&
+ /* Whenever we send anything different from a
+ * HelloRequest we should be in a handshake - double check. */
+ if( ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
+ hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) &&
ssl->handshake == NULL )
{
MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
@@ -3295,8 +3297,8 @@
/* Either send now, or just save to be sent (and resent) later */
#if defined(MBEDTLS_SSL_PROTO_DTLS)
if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
- ( ssl->out_msgtype != MBEDTLS_SSL_MSG_HANDSHAKE ||
- hs_type != MBEDTLS_SSL_HS_HELLO_REQUEST ) )
+ ! ( ssl->out_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
+ hs_type == MBEDTLS_SSL_HS_HELLO_REQUEST ) )
{
if( ( ret = ssl_flight_append( ssl ) ) != 0 )
{