commit 3d78e08ac0d05c49fb02ce6a2a1d73b9b2a1f21a
author Jerry Yu <jerry.h.yu@arm.com> Wed Nov 23 18:26:20 2022 +0800
committer Jerry Yu <jerry.h.yu@arm.com> Mon Nov 28 17:34:06 2022 +0800
tree d26235b701e1c9bf56fb020a26785bfb97e6b8ed
parent a5db6c0ce3ab6199f0a38db0138389dd63de1b76

erase early secrets and transcripts

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>

library/ssl_tls13_keys.c

diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index 43f6ab6..3d20ab7 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -1124,7 +1124,7 @@
     if( ret != 0 )
     {
         MBEDTLS_SSL_DEBUG_RET( 1, "ssl_tls13_get_cipher_key_info", ret );
-        return( ret );
+        goto cleanup;
     }
 
     md_type = ciphersuite_info->mac;
@@ -1141,7 +1141,7 @@
         MBEDTLS_SSL_DEBUG_RET( 1,
                                "mbedtls_ssl_get_handshake_transcript",
                                ret );
-        return( ret );
+        goto cleanup;
     }
 
     ret = mbedtls_ssl_tls13_derive_early_secrets(
@@ -1151,7 +1151,7 @@
     {
         MBEDTLS_SSL_DEBUG_RET(
             1, "mbedtls_ssl_tls13_derive_early_secrets", ret );
-        return( ret );
+        goto cleanup;
     }
 
     MBEDTLS_SSL_DEBUG_BUF(
@@ -1181,7 +1181,7 @@
     if( ret != 0 )
     {
         MBEDTLS_SSL_DEBUG_RET( 1, "ssl_tls13_make_traffic_key", ret );
-        return( 0 );
+        goto cleanup;
     }
     traffic_keys->key_len = key_len;
     traffic_keys->iv_len = iv_len;
@@ -1196,7 +1196,12 @@
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= ssl_tls13_generate_early_key" ) );
 
-    return( 0 );
+cleanup:
+    /* Erase secret and transcript */
+    mbedtls_platform_zeroize(
+        tls13_early_secrets, sizeof( mbedtls_ssl_tls13_early_secrets ) );
+    mbedtls_platform_zeroize( transcript, sizeof( transcript ) );
+    return( ret );
 }
 
 int mbedtls_ssl_tls13_compute_early_transform( mbedtls_ssl_context *ssl )