| From 6427f1accc54b515bb899370f1a662bfcb1caa52 Mon Sep 17 00:00:00 2001 |
| From: Alexandru Moise <alexandru.moise@windriver.com> |
| Date: Tue, 7 Feb 2017 11:16:13 +0200 |
| Subject: [PATCH 2/2] crypto/evp: harden AEAD ciphers. |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| Originally a crash in 32-bit build was reported CHACHA20-POLY1305 |
| cipher. The crash is triggered by truncated packet and is result |
| of excessive hashing to the edge of accessible memory. Since hash |
| operation is read-only it is not considered to be exploitable |
| beyond a DoS condition. Other ciphers were hardened. |
| |
| Thanks to Robert Święcki for report. |
| |
| CVE-2017-3731 |
| |
| Backported from upstream commit: |
| 2198b3a55de681e1f3c23edb0586afe13f438051 |
| |
| Upstream-Status: Backport |
| |
| Reviewed-by: Rich Salz <rsalz@openssl.org> |
| Signed-off-by: Alexandru Moise <alexandru.moise@windriver.com> |
| --- |
| crypto/evp/e_aes.c | 7 ++++++- |
| 1 file changed, 6 insertions(+), 1 deletion(-) |
| |
| diff --git a/crypto/evp/e_aes.c b/crypto/evp/e_aes.c |
| index 1734a82..16dcd10 100644 |
| --- a/crypto/evp/e_aes.c |
| +++ b/crypto/evp/e_aes.c |
| @@ -1235,10 +1235,15 @@ static int aes_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr) |
| { |
| unsigned int len = c->buf[arg - 2] << 8 | c->buf[arg - 1]; |
| /* Correct length for explicit IV */ |
| + if (len < EVP_GCM_TLS_EXPLICIT_IV_LEN) |
| + return 0; |
| len -= EVP_GCM_TLS_EXPLICIT_IV_LEN; |
| /* If decrypting correct for tag too */ |
| - if (!c->encrypt) |
| + if (!c->encrypt) { |
| + if (len < EVP_GCM_TLS_TAG_LEN) |
| + return 0; |
| len -= EVP_GCM_TLS_TAG_LEN; |
| + } |
| c->buf[arg - 2] = len >> 8; |
| c->buf[arg - 1] = len & 0xff; |
| } |
| -- |
| 2.10.2 |
| |