LibreSSL : Truncated packet could crash via OOB read

This patch is originally from master branch of OpenSSL.
- 2198b3a crypto/evp: harden AEAD ciphers.
- 8e20499 crypto/evp: harden RC4_MD5 cipher.

ok tom@

2 files changed, 10 insertions, 3 deletions

diff --git a/src/lib/libcrypto/evp/e_aes.c b/src/lib/libcrypto/evp/e_aes.c
index 71a18363f1..97cb5154a5 100644
--- a/src/lib/libcrypto/evp/e_aes.c
+++ b/src/lib/libcrypto/evp/e_aes.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: e_aes.c,v 1.32 2017/01/29 17:49:23 beck Exp $ */
+/* $OpenBSD: e_aes.c,v 1.33 2017/01/31 13:17:21 inoguchi Exp $ */
 /* ====================================================================
  * Copyright (c) 2001-2011 The OpenSSL Project.  All rights reserved.
  *
@@ -807,11 +807,16 @@ aes_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
                             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;
                 }
diff --git a/src/lib/libcrypto/evp/e_rc4_hmac_md5.c b/src/lib/libcrypto/evp/e_rc4_hmac_md5.c
index a1fc0066e6..ac73361fa3 100644
--- a/src/lib/libcrypto/evp/e_rc4_hmac_md5.c
+++ b/src/lib/libcrypto/evp/e_rc4_hmac_md5.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: e_rc4_hmac_md5.c,v 1.7 2016/11/05 10:47:57 miod Exp $ */
+/* $OpenBSD: e_rc4_hmac_md5.c,v 1.8 2017/01/31 13:17:21 inoguchi Exp $ */
 /* ====================================================================
  * Copyright (c) 2011 The OpenSSL Project.  All rights reserved.
  *
@@ -262,6 +262,8 @@ rc4_hmac_md5_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
                         unsigned int len = p[arg - 2] << 8 | p[arg - 1];
 
                         if (!ctx->encrypt) {
+                                if (len < MD5_DIGEST_LENGTH)
+                                        return -1;
                                 len -= MD5_DIGEST_LENGTH;
                                 p[arg - 2] = len >> 8;
                                 p[arg - 1] = len;