diff options
Diffstat (limited to 'lib/libssl/t1_lib.c')
| -rw-r--r-- | lib/libssl/t1_lib.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/lib/libssl/t1_lib.c b/lib/libssl/t1_lib.c index 3022469ea91..6853bc210ee 100644 --- a/lib/libssl/t1_lib.c +++ b/lib/libssl/t1_lib.c @@ -1,4 +1,4 @@ -/* $OpenBSD: t1_lib.c,v 1.88 2016/08/27 15:58:06 jsing Exp $ */ +/* $OpenBSD: t1_lib.c,v 1.89 2016/09/22 06:57:40 guenther Exp $ */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * @@ -2163,9 +2163,16 @@ tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen, HMAC_CTX hctx; EVP_CIPHER_CTX ctx; SSL_CTX *tctx = s->initial_ctx; - /* Need at least keyname + iv + some encrypted data */ - if (eticklen < 48) + + /* + * The API guarantees EVP_MAX_IV_LENGTH bytes of space for + * the iv to tlsext_ticket_key_cb(). Since the total space + * 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) return 2; + /* Initialize session ticket encryption and HMAC contexts */ HMAC_CTX_init(&hctx); EVP_CIPHER_CTX_init(&ctx); @@ -2174,10 +2181,12 @@ tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen, int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16, &ctx, &hctx, 0); if (rv < 0) { + HMAC_CTX_cleanup(&hctx); EVP_CIPHER_CTX_cleanup(&ctx); return -1; } if (rv == 0) { + HMAC_CTX_cleanup(&hctx); EVP_CIPHER_CTX_cleanup(&ctx); return 2; } @@ -2192,15 +2201,26 @@ tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen, EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, tctx->tlsext_tick_aes_key, etick + 16); } - /* Attempt to process session ticket, first conduct sanity and + + /* + * Attempt to process session ticket, first conduct sanity and * integrity checks on ticket. */ mlen = HMAC_size(&hctx); if (mlen < 0) { + HMAC_CTX_cleanup(&hctx); EVP_CIPHER_CTX_cleanup(&ctx); return -1; } + + /* Sanity check ticket length: must exceed keyname + IV + HMAC */ + if (eticklen < 16 + EVP_CIPHER_CTX_iv_length(&ctx) + mlen) { + HMAC_CTX_cleanup(&hctx); + EVP_CIPHER_CTX_cleanup(&ctx); + return 2; + } eticklen -= mlen; + /* Check HMAC of encrypted ticket */ HMAC_Update(&hctx, etick, eticklen); HMAC_Final(&hctx, tick_hmac, NULL); @@ -2209,6 +2229,7 @@ tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen, EVP_CIPHER_CTX_cleanup(&ctx); return 2; } + /* 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); |