File openssl-3-CVE-2023-3817.patch of Package openssl-3.34226

Overview Repositories Revisions Requests Users Attributes Meta

File openssl-3-CVE-2023-3817.patch of Package openssl-3.34226

From 1c16253f3c3a8d1e25918c3f404aae6a5b0893de Mon Sep 17 00:00:00 2001
From: Tomas Mraz <tomas@openssl.org>
Date: Tue, 25 Jul 2023 15:22:48 +0200
Subject: [PATCH 179/200] DH_check(): Do not try checking q properties if it is
 obviously invalid

If  |q| >= |p| then the q value is obviously wrong as q
is supposed to be a prime divisor of p-1.

We check if p is overly large so this added test implies that
q is not large either when performing subsequent tests using that
q value.

Otherwise if it is too large these additional checks of the q value
such as the primality test can then trigger DoS by doing overly long
computations.

Fixes CVE-2023-3817

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Todd Short <todd.short@me.com>
(Merged from https://github.com/openssl/openssl/pull/21550)

---
 crypto/dh/dh_check.c |    9 ++++++++-
 test/dhtest.c        |   12 ++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

--- a/crypto/dh/dh_check.c
+++ b/crypto/dh/dh_check.c
@@ -143,7 +143,7 @@ int DH_check(const DH *dh, int *ret)
 #ifdef FIPS_MODULE
     return DH_check_params(dh, ret);
 #else
-    int ok = 0, r;
+    int ok = 0, r, q_good = 0;
     BN_CTX *ctx = NULL;
     BIGNUM *t1 = NULL, *t2 = NULL;
     int nid = DH_get_nid((DH *)dh);
@@ -171,6 +171,13 @@ int DH_check(const DH *dh, int *ret)
         goto err;
 
     if (dh->params.q != NULL) {
+        if (BN_ucmp(dh->params.p, dh->params.q) > 0)
+            q_good = 1;
+        else
+            *ret |= DH_CHECK_INVALID_Q_VALUE;
+    }
+
+    if (q_good) {
         if (BN_cmp(dh->params.g, BN_value_one()) <= 0)
             *ret |= DH_NOT_SUITABLE_GENERATOR;
         else if (BN_cmp(dh->params.g, dh->params.p) >= 0)
--- a/test/dhtest.c
+++ b/test/dhtest.c
@@ -124,6 +124,15 @@ static int dh_test(void)
     /* We'll have a stale error on the queue from the above test so clear it */
     ERR_clear_error();
 
+    if (!TEST_ptr(BN_copy(q, p)) || !TEST_true(BN_add(q, q, BN_value_one())))
+        goto err3;
+
+    if (!TEST_true(DH_check(dh, &i)))
+        goto err3;
+    if (!TEST_true(i & DH_CHECK_INVALID_Q_VALUE)
+        || !TEST_false(i & DH_CHECK_Q_NOT_PRIME))
+        goto err3;
+
     /* Modulus of size: dh check max modulus bits + 1 */
     if (!TEST_true(BN_set_word(p, 1))
             || !TEST_true(BN_lshift(p, p, OPENSSL_DH_CHECK_MAX_MODULUS_BITS)))
@@ -135,6 +144,9 @@ static int dh_test(void)
     if (!TEST_false(DH_check(dh, &i)))
         goto err3;
 
+    /* We'll have a stale error on the queue from the above test so clear it */
+    ERR_clear_error();
+
     /*
      * II) key generation
      */

Places

File openssl-3-CVE-2023-3817.patch of Package openssl-3.34226

Places