openssl: CVE: CVE-2017-3731

If an SSL/TLS server or client is running on a 32-bit host, and a
specific cipher is being used, then a truncated packet can cause that
server or client  to perform an out-of-bounds read, usually resulting
in a crash.

Backported from:
https://github.com/openssl/openssl/commit/8e20499629b6bcf868d0072c7011e590b5c2294d
https://github.com/openssl/openssl/commit/2198b3a55de681e1f3c23edb0586afe13f438051

* CVE: CVE-2017-3731

Upstream-status: Backport

(From OE-Core rev: 1fe1cb3e6e03b4f7f0d30b2b67edc8809a18fe70)

Signed-off-by: Alexandru Moise <alexandru.moise@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/meta/recipes-connectivity/openssl/openssl/0002-CVE-2017-3731.patch b/meta/recipes-connectivity/openssl/openssl/0002-CVE-2017-3731.patch
new file mode 100644
index 0000000000..b56b2d5bd3
--- /dev/null
+++ b/meta/recipes-connectivity/openssl/openssl/0002-CVE-2017-3731.patch
@@ -0,0 +1,53 @@
+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
+