File openssl-CVE-2023-5678.patch of Package openssl-1_1.31470
From db925ae2e65d0d925adef429afc37f75bd1c2017 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)
---
crypto/dh/dh_check.c | 12 ++++++++++++
crypto/dh/dh_err.c | 3 ++-
crypto/dh/dh_key.c | 12 ++++++++++++
crypto/err/openssl.txt | 1 +
include/crypto/dherr.h | 2 +-
include/openssl/dh.h | 6 +++---
include/openssl/dherr.h | 3 ++-
7 files changed, 33 insertions(+), 6 deletions(-)
Index: openssl-1.1.0i/crypto/dh/dh_check.c
===================================================================
--- openssl-1.1.0i.orig/crypto/dh/dh_check.c
+++ openssl-1.1.0i/crypto/dh/dh_check.c
@@ -227,6 +227,18 @@ static int dh_check_pub_key_int(const DH
*/
int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret)
{
+ /* 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_PUB_KEY, DH_R_MODULUS_TOO_LARGE);
+ *ret = DH_MODULUS_TOO_LARGE | DH_CHECK_PUBKEY_INVALID;
+ return 0;
+ }
+
+ if (dh->q != NULL && BN_ucmp(dh->p, dh->q) < 0) {
+ *ret |= DH_CHECK_INVALID_Q_VALUE | DH_CHECK_PUBKEY_INVALID;
+ return 1;
+ }
+
return dh_check_pub_key_int(dh, dh->q, pub_key, ret);
}
Index: openssl-1.1.0i/crypto/dh/dh_key.c
===================================================================
--- openssl-1.1.0i.orig/crypto/dh/dh_key.c
+++ openssl-1.1.0i/crypto/dh/dh_key.c
@@ -44,6 +44,13 @@ int DH_compute_key(unsigned char *key, c
return 0;
}
#endif
+
+ if (dh->q != NULL
+ && BN_num_bits(dh->q) > OPENSSL_DH_MAX_MODULUS_BITS) {
+ DHerr(DH_F_DH_COMPUTE_KEY, DH_R_Q_TOO_LARGE);
+ return 0;
+ }
+
return dh->meth->compute_key(key, pub_key, dh);
}
@@ -120,6 +127,12 @@ static int generate_key(DH *dh)
}
#endif
+ 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;
Index: openssl-1.1.0i/doc/crypto/DH_generate_parameters.pod
===================================================================
--- openssl-1.1.0i.orig/doc/crypto/DH_generate_parameters.pod
+++ openssl-1.1.0i/doc/crypto/DH_generate_parameters.pod
@@ -61,6 +61,10 @@ The generator B<g> is not suitable.
Note that the lack of this bit doesn't guarantee that B<g> is
suitable, unless B<p> is known to be a strong prime.
+=item DH_MODULUS_TOO_LARGE
+
+The modulus is too large.
+
=back
DH_check() confirms that the Diffie-Hellman parameters B<dh> are valid. The
Index: openssl-1.1.0i/include/openssl/dh.h
===================================================================
--- openssl-1.1.0i.orig/include/openssl/dh.h
+++ openssl-1.1.0i/include/openssl/dh.h
@@ -77,8 +77,9 @@ DECLARE_ASN1_ITEM(DHparams)
# 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
+# define DH_MODULUS_TOO_LARGE 0x100 /* +DH_check_pub_key */
/* DH_check_pub_key error codes */
# define DH_CHECK_PUBKEY_TOO_SMALL 0x01
@@ -347,6 +348,7 @@ int ERR_load_DH_strings(void);
# define DH_F_DHPARAMS_PRINT_FP 101
# define DH_F_DH_BUILTIN_GENPARAMS 106
# define DH_F_DH_CHECK 126
+# define DH_F_DH_CHECK_PUB_KEY 128
# define DH_F_DH_CMS_DECRYPT 114
# define DH_F_DH_CMS_SET_PEERKEY 115
# define DH_F_DH_CMS_SET_SHARED_INFO 116
@@ -384,6 +386,7 @@ 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
# ifdef __cplusplus
Index: openssl-1.1.0i/crypto/dh/dh_err.c
===================================================================
--- openssl-1.1.0i.orig/crypto/dh/dh_err.c
+++ openssl-1.1.0i/crypto/dh/dh_err.c
@@ -23,6 +23,7 @@ static ERR_STRING_DATA DH_str_functs[] =
{ERR_FUNC(DH_F_DHPARAMS_PRINT_FP), "DHparams_print_fp"},
{ERR_FUNC(DH_F_DH_BUILTIN_GENPARAMS), "dh_builtin_genparams"},
{ERR_FUNC(DH_F_DH_CHECK), "DH_check"},
+ {ERR_FUNC(DH_F_DH_CHECK_PUB_KEY), "DH_check_pub_key"},
{ERR_FUNC(DH_F_DH_CMS_DECRYPT), "dh_cms_decrypt"},
{ERR_FUNC(DH_F_DH_CMS_SET_PEERKEY), "dh_cms_set_peerkey"},
{ERR_FUNC(DH_F_DH_CMS_SET_SHARED_INFO), "dh_cms_set_shared_info"},
@@ -62,6 +63,7 @@ static ERR_STRING_DATA DH_str_reasons[]
{ERR_REASON(DH_R_NON_FIPS_METHOD), "non FIPS method"},
{ERR_REASON(DH_R_PARAMETER_ENCODING_ERROR), "parameter encoding error"},
{ERR_REASON(DH_R_PEER_KEY_ERROR), "peer key error"},
+ {ERR_REASON(DH_R_Q_TOO_LARGE), "q too large"},
{ERR_REASON(DH_R_SHARED_INFO_ERROR), "shared info error"},
{0, NULL}
};
