commit 435208a9490ebe24764b008592360a0b958c4d9c
author Jerry Yu <jerry.h.yu@arm.com> Wed Oct 13 11:22:16 2021 +0800
committer Jerry Yu <jerry.h.yu@arm.com> Mon Oct 25 10:41:29 2021 +0800
tree 719a9b1c86f74f9a2585a1563645aeb2fb0c3fe6
parent f532bb2577180650174bfd227ca946a410328f59

Improve generate_handshake_keys

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 b568f3f..4fe1d5c 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -858,20 +858,23 @@
     mbedtls_md_info_t const *md_info;
     size_t md_size;
 
-    unsigned char transcript[MBEDTLS_MD_MAX_SIZE];
+    unsigned char transcript[MBEDTLS_TLS1_3_MD_MAX_SIZE];
     size_t transcript_len;
 
     mbedtls_cipher_info_t const *cipher_info;
     size_t keylen, ivlen;
 
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+    const mbedtls_ssl_ciphersuite_t *ciphersuite_info = handshake->ciphersuite_info;
+    mbedtls_ssl_tls1_3_handshake_secrets *tls13_hs_secrets = &handshake->tls13_hs_secrets;
+
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_tls13_generate_handshake_keys" ) );
 
-    cipher_info = mbedtls_cipher_info_from_type(
-                    ssl->handshake->ciphersuite_info->cipher );
+    cipher_info = mbedtls_cipher_info_from_type( ciphersuite_info->cipher );
     keylen = cipher_info->key_bitlen >> 3;
     ivlen = cipher_info->iv_size;
 
-    md_type = ssl->handshake->ciphersuite_info->mac;
+    md_type = ciphersuite_info->mac;
     md_info = mbedtls_md_info_from_type( md_type );
     md_size = mbedtls_md_get_size( md_info );
 
@@ -888,9 +891,8 @@
     }
 
     ret = mbedtls_ssl_tls1_3_derive_handshake_secrets( md_type,
-                ssl->handshake->tls1_3_master_secrets.handshake,
-                transcript, transcript_len,
-                &ssl->handshake->tls13_hs_secrets );
+                                    handshake->tls1_3_master_secrets.handshake,
+                                    transcript, transcript_len, tls13_hs_secrets );
     if( ret != 0 )
     {
         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls1_3_derive_handshake_secrets",
@@ -899,11 +901,10 @@
     }
 
     MBEDTLS_SSL_DEBUG_BUF( 4, "Client handshake traffic secret",
-                    ssl->handshake->tls13_hs_secrets.client_handshake_traffic_secret,
+                    tls13_hs_secrets->client_handshake_traffic_secret,
                     md_size );
-
     MBEDTLS_SSL_DEBUG_BUF( 4, "Server handshake traffic secret",
-                    ssl->handshake->tls13_hs_secrets.server_handshake_traffic_secret,
+                    tls13_hs_secrets->server_handshake_traffic_secret,
                     md_size );
 
     /*
@@ -914,27 +915,26 @@
     {
         ssl->f_export_keys( ssl->p_export_keys,
                 MBEDTLS_SSL_KEY_EXPORT_TLS13_CLIENT_HANDSHAKE_TRAFFIC_SECRET,
-                ssl->handshake->tls13_hs_secrets.client_handshake_traffic_secret,
+                tls13_hs_secrets->client_handshake_traffic_secret,
                 md_size,
-                ssl->handshake->randbytes + 32,
-                ssl->handshake->randbytes,
+                handshake->randbytes + 32,
+                handshake->randbytes,
                 MBEDTLS_SSL_TLS_PRF_NONE /* TODO: FIX! */ );
 
         ssl->f_export_keys( ssl->p_export_keys,
                 MBEDTLS_SSL_KEY_EXPORT_TLS13_SERVER_HANDSHAKE_TRAFFIC_SECRET,
-                ssl->handshake->tls13_hs_secrets.server_handshake_traffic_secret,
+                tls13_hs_secrets->server_handshake_traffic_secret,
                 md_size,
-                ssl->handshake->randbytes + 32,
-                ssl->handshake->randbytes,
+                handshake->randbytes + 32,
+                handshake->randbytes,
                 MBEDTLS_SSL_TLS_PRF_NONE /* TODO: FIX! */ );
     }
 #endif /* MBEDTLS_SSL_EXPORT_KEYS */
 
     ret = mbedtls_ssl_tls1_3_make_traffic_keys( md_type,
-                ssl->handshake->tls13_hs_secrets.client_handshake_traffic_secret,
-                ssl->handshake->tls13_hs_secrets.server_handshake_traffic_secret,
-                md_size,
-                keylen, ivlen, traffic_keys );
+                            tls13_hs_secrets->client_handshake_traffic_secret,
+                            tls13_hs_secrets->server_handshake_traffic_secret,
+                            md_size, keylen, ivlen, traffic_keys );
     if( ret != 0 )
     {
         MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls1_3_make_traffic_keys", ret );