commit a6f99a1aab741afd9fb60d91e2a2afb1c207e0e1
author Gilles Peskine <Gilles.Peskine@arm.com> Wed Apr 13 13:24:56 2022 +0200
committer Gilles Peskine <Gilles.Peskine@arm.com> Wed Apr 13 13:45:24 2022 +0200
tree 2f6b41639841c6d499c63a8d09261f4d9eaa5cf7
parent bcb2ab0cb3377b9b6387b43008870138e1c1f425

Fix crash with DTLS_CONNECTION_ID but not other SSL features

In configurations with MBEDTLS_SSL_DTLS_CONNECTION_ID enabled but none of
MBEDTLS_SSL_HW_RECORD_ACCEL, MBEDTLS_SSL_EXPORT_KEYS or MBEDTLS_DEBUG_C,
DTLS handshakes using CID would crash due to a null pointer dereference.
Fix this. Fixes #3998.

Detected by running compat.sh in config-ccm-psk-dtls1_2.h.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

library/ssl_tls.c

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index c85291e..4878585 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -990,6 +990,7 @@
 
 #if !defined(MBEDTLS_SSL_HW_RECORD_ACCEL) && \
     !defined(MBEDTLS_SSL_EXPORT_KEYS) && \
+    !defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) && \
     !defined(MBEDTLS_DEBUG_C)
     ssl = NULL; /* make sure we don't use it except for those cases */
     (void) ssl;