Provide a derr label (decode/decrypt error) in tls1_decrypt_ticket().

This handles the ret = 2 case and makes the code more readable.

ok tb@

1 files changed, 29 insertions, 41 deletions

diff --git a/src/lib/libssl/t1_lib.c b/src/lib/libssl/t1_lib.c
index 6af6d77edd..d21e6ef646 100644
--- a/src/lib/libssl/t1_lib.c
+++ b/src/lib/libssl/t1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_lib.c,v 1.159 2019/04/22 15:12:20 jsing Exp $ */
+/* $OpenBSD: t1_lib.c,v 1.160 2019/04/22 16:03:54 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -896,10 +896,8 @@ tls_decrypt_ticket(SSL *s, CBS *session_id, const unsigned char *etick,
          * required for a session cookie is never less than this,
          * this check isn't too strict.  The exact check comes later.
          */
-        if (eticklen < 16 + EVP_MAX_IV_LENGTH) {
-                ret = 2;
-                goto done;
-        }
+        if (eticklen < 16 + EVP_MAX_IV_LENGTH)
+                goto derr;
 
         /* Initialize session ticket encryption and HMAC contexts */
         if (tctx->internal->tlsext_ticket_key_cb) {
@@ -908,19 +906,15 @@ tls_decrypt_ticket(SSL *s, CBS *session_id, const unsigned char *etick,
                     nctick, nctick + 16, &ctx, &hctx, 0);
                 if (rv < 0)
                         goto err;
-                if (rv == 0) {
-                        ret = 2;
-                        goto done;
-                }
+                if (rv == 0)
+                        goto derr;
                 if (rv == 2)
                         renew_ticket = 1;
         } else {
                 /* Check key name matches */
                 if (timingsafe_memcmp(etick,
-                    tctx->internal->tlsext_tick_key_name, 16)) {
-                        ret = 2;
-                        goto done;
-                }
+                    tctx->internal->tlsext_tick_key_name, 16))
+                        goto derr;
                 HMAC_Init_ex(&hctx, tctx->internal->tlsext_tick_hmac_key,
                     16, EVP_sha256(), NULL);
                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
@@ -936,10 +930,8 @@ tls_decrypt_ticket(SSL *s, CBS *session_id, const unsigned char *etick,
                 goto err;
 
         /* Sanity check ticket length: must exceed keyname + IV + HMAC */
-        if (eticklen <= 16 + EVP_CIPHER_CTX_iv_length(&ctx) + mlen) {
-                ret = 2;
-                goto done;
-        }
+        if (eticklen <= 16 + EVP_CIPHER_CTX_iv_length(&ctx) + mlen)
+                goto derr;
         eticklen -= mlen;
 
         /* Check HMAC of encrypted ticket */
@@ -947,38 +939,29 @@ tls_decrypt_ticket(SSL *s, CBS *session_id, const unsigned char *etick,
             HMAC_Final(&hctx, tick_hmac, NULL) <= 0)
                 goto err;
 
-        if (timingsafe_memcmp(tick_hmac, etick + eticklen, mlen)) {
-                ret = 2;
-                goto done;
-        }
+        if (timingsafe_memcmp(tick_hmac, etick + eticklen, mlen))
+                goto derr;
 
         /* Attempt to decrypt session data */
         /* Move p after IV to start of encrypted ticket, update length */
         p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
         eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
-        if ((sdec = malloc(eticklen)) == NULL) {
-                ret = -1;
-                goto done;
-        }
-        if (EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen) <= 0) {
-                ret = 2;
-                goto done;
-        }
-        if (EVP_DecryptFinal_ex(&ctx, sdec + slen, &mlen) <= 0) {
-                ret = 2;
-                goto done;
-        }
+        if ((sdec = malloc(eticklen)) == NULL)
+                goto err;
+        if (EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen) <= 0)
+                goto derr;
+        if (EVP_DecryptFinal_ex(&ctx, sdec + slen, &mlen) <= 0)
+                goto derr;
+
         slen += mlen;
         p = sdec;
 
-        if ((sess = d2i_SSL_SESSION(NULL, &p, slen)) == NULL) {
-                /*
-                 * For session parse failure, indicate that we need to send a
-                 * new ticket.
-                 */
-                ret = 2;
-                goto done;
-        }
+        /*
+         * For session parse failures, indicate that we need to send a new
+         * ticket.
+         */
+        if ((sess = d2i_SSL_SESSION(NULL, &p, slen)) == NULL)
+                goto derr;
 
         /*
          * The session ID, if non-empty, is used by some clients to detect that
@@ -1000,8 +983,13 @@ tls_decrypt_ticket(SSL *s, CBS *session_id, const unsigned char *etick,
 
         goto done;
 
+ derr:
+        ret = 2;
+        goto done;
+
  err:
         ret = -1;
+        goto done;
 
  done:
         free(sdec);