Check for negative EVP_CIPHER_CTX_iv_length() return in libssl

ok beck

1 files changed, 8 insertions, 6 deletions

diff --git a/src/lib/libssl/t1_lib.c b/src/lib/libssl/t1_lib.c
index 85d5eaa633..9680c8d213 100644
--- a/src/lib/libssl/t1_lib.c
+++ b/src/lib/libssl/t1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_lib.c,v 1.197 2022/11/26 16:08:56 tb Exp $ */
+/* $OpenBSD: t1_lib.c,v 1.198 2023/11/18 10:51:09 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -987,7 +987,7 @@ tls_decrypt_ticket(SSL *s, CBS *ticket, int *alert, SSL_SESSION **psess)
         HMAC_CTX *hctx = NULL;
         EVP_CIPHER_CTX *cctx = NULL;
         SSL_CTX *tctx = s->initial_ctx;
-        int slen, hlen;
+        int slen, hlen, iv_len;
         int alert_desc = SSL_AD_INTERNAL_ERROR;
         int ret = TLS1_TICKET_FATAL_ERROR;
 
@@ -1027,12 +1027,13 @@ tls_decrypt_ticket(SSL *s, CBS *ticket, int *alert, SSL_SESSION **psess)
                         s->tlsext_ticket_expected = 1;
                 }
 
+                if ((iv_len = EVP_CIPHER_CTX_iv_length(cctx)) < 0)
+                        goto err;
                 /*
                  * Now that the cipher context is initialised, we can extract
                  * the IV since its length is known.
                  */
-                if (!CBS_get_bytes(ticket, &ticket_iv,
-                    EVP_CIPHER_CTX_iv_length(cctx)))
+                if (!CBS_get_bytes(ticket, &ticket_iv, iv_len))
                         goto derr;
         } else {
                 /* Check that the key name matches. */
@@ -1040,8 +1041,9 @@ tls_decrypt_ticket(SSL *s, CBS *ticket, int *alert, SSL_SESSION **psess)
                     tctx->tlsext_tick_key_name,
                     sizeof(tctx->tlsext_tick_key_name)))
                         goto derr;
-                if (!CBS_get_bytes(ticket, &ticket_iv,
-                    EVP_CIPHER_iv_length(EVP_aes_128_cbc())))
+                if ((iv_len = EVP_CIPHER_iv_length(EVP_aes_128_cbc())) < 0)
+                        goto err;
+                if (!CBS_get_bytes(ticket, &ticket_iv, iv_len))
                         goto derr;
                 if (!EVP_DecryptInit_ex(cctx, EVP_aes_128_cbc(), NULL,
                     tctx->tlsext_tick_aes_key, CBS_data(&ticket_iv)))