commit a3344f7bacd803e487012c0ad0cfef5316edf036
author Dave Rodgman <dave.rodgman@arm.com> Mon May 30 11:40:21 2022 +0100
committer GitHub <noreply@github.com> Mon May 30 11:40:21 2022 +0100
tree e350fb2fff5e3917a97d2079fbd6ccfc4a9004b8
parent 52625b739e21e9bab614ee7ad1942c626ae59525
parent 114203814a32125ef8ca6145ec15a3746404bf97

Merge pull request #5767 from leorosen/avoid-null-args

Avoid potentially passing NULL arguments

library/ssl_tls12_server.c

diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index d092633..1c9e5cd 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -2504,8 +2504,9 @@
 
 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) || \
     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
-    if ( mbedtls_ssl_ciphersuite_uses_ec(
-         mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite ) ) )
+    const mbedtls_ssl_ciphersuite_t *suite =
+        mbedtls_ssl_ciphersuite_from_id( ssl->session_negotiate->ciphersuite );
+    if ( suite != NULL && mbedtls_ssl_ciphersuite_uses_ec( suite) )
     {
         ssl_write_supported_point_formats_ext( ssl, p + 2 + ext_len, &olen );
         ext_len += olen;
@@ -2825,7 +2826,14 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
-    if( ! mbedtls_pk_can_do( mbedtls_ssl_own_key( ssl ), MBEDTLS_PK_ECKEY ) )
+    const mbedtls_pk_context *private_key = mbedtls_ssl_own_key( ssl );
+    if( private_key == NULL)
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "got no server private key" ) );
+        return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
+    }
+
+    if( ! mbedtls_pk_can_do( private_key, MBEDTLS_PK_ECKEY ) )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) );
         return( MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH );
@@ -3160,6 +3168,12 @@
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_SERVER_SIGNATURE_ENABLED)
     if( mbedtls_ssl_ciphersuite_uses_server_signature( ciphersuite_info ) )
     {
+        if( dig_signed == NULL )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "should never happen" ) );
+            return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
+        }
+
         size_t dig_signed_len = ssl->out_msg + ssl->out_msglen - dig_signed;
         size_t hashlen = 0;
 #if defined(MBEDTLS_USE_PSA_CRYPTO)