Fix CVE-2023-5678

Fix CVE-2023-5678: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys or parameters may be very slow Resolves: RHEL-16538 Signed-off-by: Clemens Lang <cllang@redhat.com>
2023-11-15 17:37:26 +01:00 · 2023-11-15 17:37:26 +01:00 · c7561b3a10
commit c7561b3a10
parent dba9cab3de
2 changed files with 162 additions and 1 deletions
--- a/openssl-1.1.1-cve-2023-5678.patch
+++ b/openssl-1.1.1-cve-2023-5678.patch
@ -0,0 +1,154 @@
+From 0814467cc1b6a2839877277d3efa69cdd4582dd7 Mon Sep 17 00:00:00 2001
+From: Richard Levitte <levitte@openssl.org>
+Date: Fri, 20 Oct 2023 09:18:19 +0200
+Subject: [PATCH] Make DH_check_pub_key() and DH_generate_key() safer yet
+
+We already check for an excessively large P in DH_generate_key(), but not in
+DH_check_pub_key(), and none of them check for an excessively large Q.
+
+This change adds all the missing excessive size checks of P and Q.
+
+It's to be noted that behaviours surrounding excessively sized P and Q
+differ.  DH_check() raises an error on the excessively sized P, but only
+sets a flag for the excessively sized Q.  This behaviour is mimicked in
+DH_check_pub_key().
+
+Reviewed-by: Tomas Mraz <tomas@openssl.org>
+Reviewed-by: Matt Caswell <matt@openssl.org>
+Reviewed-by: Hugo Landau <hlandau@openssl.org>
+(Merged from https://github.com/openssl/openssl/pull/22518)
+
+(cherry picked from commit ddeb4b6c6d527e54ce9a99cba785c0f7776e54b6)
+Backported-by: Clemens Lang <cllang@redhat.com>
+---
+ crypto/dh/dh_check.c    | 17 +++++++++++++++++
+ crypto/dh/dh_err.c      |  1 +
+ crypto/dh/dh_key.c      | 10 ++++++++++
+ crypto/err/openssl.txt  |  1 +
+ include/openssl/dh.h    |  6 ++++--
+ include/openssl/dherr.h |  1 +
+ 6 files changed, 34 insertions(+), 2 deletions(-)
+
+diff --git a/crypto/dh/dh_check.c b/crypto/dh/dh_check.c
+index ae1b03bc92..424a3bb4cd 100644
+--- a/crypto/dh/dh_check.c
+++ b/crypto/dh/dh_check.c
+@@ -198,10 +198,27 @@ int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret)
+     BN_CTX *ctx = NULL;
+ 
+     *ret = 0;
+
+     ctx = BN_CTX_new();
+     if (ctx == NULL)
+         goto err;
+     BN_CTX_start(ctx);
+
+    /* Don't do any checks at all with an excessively large modulus */
+    if (BN_num_bits(dh->p) > OPENSSL_DH_CHECK_MAX_MODULUS_BITS) {
+        DHerr(DH_F_DH_CHECK, DH_R_MODULUS_TOO_LARGE);
+        *ret = DH_MODULUS_TOO_LARGE | DH_CHECK_PUBKEY_INVALID;
+        goto err;
+    }
+    if (dh->q != NULL && BN_ucmp(dh->p, dh->q) < 0) {
+        *ret |= DH_CHECK_INVALID_Q_VALUE | DH_CHECK_PUBKEY_INVALID;
+        /* This may look strange here, but returning 1 after setting ret is
+         * correct. See also the behavior of the pub_key^q == 1 mod p check
+         * further down, which behaves in the same way. */
+        ok = 1;
+        goto err;
+    }
+
+     tmp = BN_CTX_get(ctx);
+     if (tmp == NULL || !BN_set_word(tmp, 1))
+         goto err;
+diff --git a/crypto/dh/dh_err.c b/crypto/dh/dh_err.c
+index 92800d3fcc..b3b1e7a706 100644
+--- a/crypto/dh/dh_err.c
+++ b/crypto/dh/dh_err.c
+@@ -87,6 +87,7 @@ static const ERR_STRING_DATA DH_str_reasons[] = {
+     {ERR_PACK(ERR_LIB_DH, 0, DH_R_PARAMETER_ENCODING_ERROR),
+     "parameter encoding error"},
+     {ERR_PACK(ERR_LIB_DH, 0, DH_R_PEER_KEY_ERROR), "peer key error"},
+    {ERR_PACK(ERR_LIB_DH, 0, DH_R_Q_TOO_LARGE), "q too large"},
+     {ERR_PACK(ERR_LIB_DH, 0, DH_R_SHARED_INFO_ERROR), "shared info error"},
+     {ERR_PACK(ERR_LIB_DH, 0, DH_R_UNABLE_TO_CHECK_GENERATOR),
+     "unable to check generator"},
+diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
+index 117f2fa883..9f5e6f6d4c 100644
+--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
+@@ -140,6 +140,11 @@ static int generate_key(DH *dh)
+         return 0;
+     }
+ 
+    if (dh->q != NULL && BN_num_bits(dh->q) > OPENSSL_DH_MAX_MODULUS_BITS) {
+        DHerr(DH_F_GENERATE_KEY, DH_R_Q_TOO_LARGE);
+        return 0;
+    }
+
+     ctx = BN_CTX_new();
+     if (ctx == NULL)
+         goto err;
+@@ -250,6 +255,12 @@ static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
+         DHerr(DH_F_COMPUTE_KEY, DH_R_MODULUS_TOO_LARGE);
+         goto err;
+     }
+
+    if (dh->q != NULL && BN_num_bits(dh->q) > OPENSSL_DH_MAX_MODULUS_BITS) {
+        DHerr(DH_F_COMPUTE_KEY, DH_R_Q_TOO_LARGE);
+        goto err;
+    }
+
+ #ifdef OPENSSL_FIPS
+     if (FIPS_mode()
+         && (BN_num_bits(dh->p) < OPENSSL_DH_FIPS_MIN_MODULUS_BITS)) {
+diff --git a/crypto/err/openssl.txt b/crypto/err/openssl.txt
+index c0a3cd720b..5e0ff47516 100644
+--- a/crypto/err/openssl.txt
+++ b/crypto/err/openssl.txt
+@@ -2151,6 +2151,7 @@DH_R_NO_PARAMETERS_SET:107:no parameters set
+ DH_R_NO_PRIVATE_VALUE:100:no private value
+ DH_R_PARAMETER_ENCODING_ERROR:105:parameter encoding error
+ DH_R_PEER_KEY_ERROR:111:peer key error
+DH_R_Q_TOO_LARGE:130:q too large
+ DH_R_SHARED_INFO_ERROR:113:shared info error
+ DH_R_UNABLE_TO_CHECK_GENERATOR:121:unable to check generator
+ DSA_R_BAD_Q_VALUE:102:bad q value
+diff --git a/include/openssl/dh.h b/include/openssl/dh.h
+index 6c6ff3636a..b7df43b44f 100644
+--- a/include/openssl/dh.h
+++ b/include/openssl/dh.h
+@@ -72,14 +72,16 @@ DECLARE_ASN1_ITEM(DHparams)
+ /* #define DH_GENERATOR_3       3 */
+ # define DH_GENERATOR_5          5
+ 
+-/* DH_check error codes */
+/* DH_check error codes, some of them shared with DH_check_pub_key */
+ # define DH_CHECK_P_NOT_PRIME            0x01
+ # define DH_CHECK_P_NOT_SAFE_PRIME       0x02
+ # define DH_UNABLE_TO_CHECK_GENERATOR    0x04
+ # define DH_NOT_SUITABLE_GENERATOR       0x08
+ # define DH_CHECK_Q_NOT_PRIME            0x10
+-# define DH_CHECK_INVALID_Q_VALUE        0x20
+# define DH_CHECK_INVALID_Q_VALUE        0x20 /* +DH_check_pub_key */
+ # define DH_CHECK_INVALID_J_VALUE        0x40
+/* DH_MODULUS_TOO_SMALL is 0x80 upstream */
+# define DH_MODULUS_TOO_LARGE            0x100 /* +DH_check_pub_key */
+ 
+ /* DH_check_pub_key error codes */
+ # define DH_CHECK_PUBKEY_TOO_SMALL       0x01
+diff --git a/include/openssl/dherr.h b/include/openssl/dherr.h
+index 528c819856..d66c35aa8e 100644
+--- a/include/openssl/dherr.h
+++ b/include/openssl/dherr.h
+@@ -87,6 +87,7 @@ int ERR_load_DH_strings(void);
+ #  define DH_R_NON_FIPS_METHOD                             202
+ #  define DH_R_PARAMETER_ENCODING_ERROR                    105
+ #  define DH_R_PEER_KEY_ERROR                              111
+#  define DH_R_Q_TOO_LARGE                                 130
+ #  define DH_R_SHARED_INFO_ERROR                           113
+ #  define DH_R_UNABLE_TO_CHECK_GENERATOR                   121
+ 
+-- 
+2.41.0
+
--- a/openssl.spec
+++ b/openssl.spec
@ -22,7 +22,7 @@
 Summary: Utilities from the general purpose cryptography library with TLS implementation
 Name: openssl
 Version: 1.1.1k
-Release: 10%{?dist}
+Release: 11%{?dist}
 Epoch: 1
 # We have to remove certain patented algorithms from the openssl source
 # tarball with the hobble-openssl script which is included below.
@ -95,6 +95,7 @@ Patch104: openssl-1.1.1-cve-2023-0286-X400.patch
 # OpenSSL 1.1.1v CVEs
 Patch105: openssl-1.1.1-cve-2023-3446.patch
 Patch106: openssl-1.1.1-cve-2023-3817.patch
+Patch107: openssl-1.1.1-cve-2023-5678.patch

 License: OpenSSL and ASL 2.0
 URL: http://www.openssl.org/
@ -226,6 +227,7 @@ cp %{SOURCE13} test/
 %patch104 -p1 -b .cve-2023-0286
 %patch105 -p1 -b .cve-2023-3446
 %patch106 -p1 -b .cve-2023-3817
+%patch107 -p1 -b .cve-2023-5678

 %build
 # Figure out which flags we want to use.
@ -509,6 +511,11 @@ export LD_LIBRARY_PATH
 %postun libs -p /sbin/ldconfig

 %changelog
+* Wed Nov 15 2023 Clemens Lang <cllang@redhat.com> - 1:1.1.1k-11
+- Fix CVE-2023-5678: Generating excessively long X9.42 DH keys or checking
+  excessively long X9.42 DH keys or parameters may be very slow
+  Resolves: RHEL-16538
+
 * Thu Oct 19 2023 Clemens Lang <cllang@redhat.com> - 1:1.1.1k-10
 - Fix CVE-2023-3446: Excessive time spent checking DH keys and parameters
  Resolves: RHEL-14245