From 91f7361f47b082ae61ffe1a7b17bb2adf213c7fe Mon Sep 17 00:00:00 2001
From: Guido Vranken <guidovranken@gmail.com>
Date: Mon, 11 Jun 2018 19:38:54 +0200
Subject: [PATCH] Reject excessively large primes in DH key generation.
CVE-2018-0732
Signed-off-by: Guido Vranken <guidovranken@gmail.com>
Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6457)
---
crypto/dh/dh_key.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
index 6901548..752542b 100644
--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
@@ -78,10 +78,15 @@ static int generate_key(DH *dh)
int ok = 0;
int generate_new_key = 0;
unsigned l;
- BN_CTX *ctx;
+ BN_CTX *ctx = NULL;
BN_MONT_CTX *mont = NULL;
BIGNUM *pub_key = NULL, *priv_key = NULL;
+ if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
+ DHerr(DH_F_GENERATE_KEY, DH_R_MODULUS_TOO_LARGE);
+ return 0;
+ }
+
ctx = BN_CTX_new();
if (ctx == NULL)
goto err;
--
2.7.4