commit a6899bb89d8e0f5d264c37d972e0fb0c1069a920
author Hanno Becker <hanno.becker@arm.com> Wed Feb 06 18:26:03 2019 +0000
committer Hanno Becker <hanno.becker@arm.com> Tue Feb 26 14:38:09 2019 +0000
tree 7aab859e3b028f4d4952fc48a69ed3ab76e05f47
parent be7f50866d3aa8a0cc174a477af1f953de1e0a81

Adapt client-side signature verification to use raw public key

We must dispatch between the peer's public key stored as part of
the peer's CRT in the current session structure (situation until
now, and future behaviour if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is
enabled), and the sole public key stored in the handshake structure
(new, if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is disabled).

library/ssl_cli.c

diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index a758524..d402249 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2650,6 +2650,8 @@
         size_t params_len = p - params;
         void *rs_ctx = NULL;
 
+        mbedtls_pk_context * peer_pk;
+
         /*
          * Handle the digitally-signed structure
          */
@@ -2752,16 +2754,21 @@
 
         MBEDTLS_SSL_DEBUG_BUF( 3, "parameters hash", hash, hashlen );
 
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+        peer_pk = &ssl->handshake->peer_pubkey;
+#else /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
         if( ssl->session_negotiate->peer_cert == NULL )
         {
             /* Should never happen */
             return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
         }
+        peer_pk = &ssl->session_negotiate->peer_cert->pk;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
         /*
          * Verify signature
          */
-        if( ! mbedtls_pk_can_do( &ssl->session_negotiate->peer_cert->pk, pk_alg ) )
+        if( !mbedtls_pk_can_do( peer_pk, pk_alg ) )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
@@ -2774,8 +2781,7 @@
             rs_ctx = &ssl->handshake->ecrs_ctx.pk;
 #endif
 
-        if( ( ret = mbedtls_pk_verify_restartable(
-                        &ssl->session_negotiate->peer_cert->pk,
+        if( ( ret = mbedtls_pk_verify_restartable( peer_pk,
                         md_alg, hash, hashlen, p, sig_len, rs_ctx ) ) != 0 )
         {
 #if defined(MBEDTLS_SSL__ECP_RESTARTABLE)