From bcc534f91bf0fc77f85efb634bc5ae6eb6030659 Mon Sep 17 00:00:00 2001 From: inoguchi Date: Wed, 19 Jan 2022 11:10:55 +0000 Subject: [PATCH] Check function return value in libtls EVP_EncryptInit_ex, EVP_DecryptInit_ex and HMAC_Init_ex are possible to fail and return error. Error from these functions will be fatal for the callback, and I choose to return -1. SSL_CTX_set_tlsext_ticket_key_cb.3 explains the return value of callback. This also could fix Coverity CID 345319. ok jsing@ tb@ --- lib/libtls/tls_server.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) diff --git a/lib/libtls/tls_server.c b/lib/libtls/tls_server.c index 0a8ec4728ea..72f797b860b 100644 --- a/lib/libtls/tls_server.c +++ b/lib/libtls/tls_server.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tls_server.c,v 1.47 2021/06/14 03:53:59 tb Exp $ */ +/* $OpenBSD: tls_server.c,v 1.48 2022/01/19 11:10:55 inoguchi Exp $ */ /* * Copyright (c) 2014 Joel Sing * @@ -185,10 +185,16 @@ tls_server_ticket_cb(SSL *ssl, unsigned char *keyname, unsigned char *iv, memcpy(keyname, key->key_name, sizeof(key->key_name)); arc4random_buf(iv, EVP_MAX_IV_LENGTH); - EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, - key->aes_key, iv); - HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key), - EVP_sha256(), NULL); + if (!EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, + key->aes_key, iv)) { + tls_set_errorx(tls_ctx, "failed to init encrypt"); + return (-1); + } + if (!HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key), + EVP_sha256(), NULL)) { + tls_set_errorx(tls_ctx, "failed to init hmac"); + return (-1); + } return (0); } else { /* get key by name */ @@ -196,10 +202,16 @@ tls_server_ticket_cb(SSL *ssl, unsigned char *keyname, unsigned char *iv, if (key == NULL) return (0); - EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, - key->aes_key, iv); - HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key), - EVP_sha256(), NULL); + if (!EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL, + key->aes_key, iv)) { + tls_set_errorx(tls_ctx, "failed to init decrypt"); + return (-1); + } + if (!HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key), + EVP_sha256(), NULL)) { + tls_set_errorx(tls_ctx, "failed to init hmac"); + return (-1); + } /* time to renew the ticket? is it the primary key? */ if (key != &tls_ctx->config->ticket_keys[0]) -- 2.20.1