diff options
author | Richard Levitte <levitte@openssl.org> | 2023-10-20 09:18:19 +0200 |
---|---|---|
committer | Hugo Landau <hlandau@openssl.org> | 2023-11-06 07:54:30 +0000 |
commit | db925ae2e65d0d925adef429afc37f75bd1c2017 (patch) | |
tree | 724a7427ca1edc0cb5e065cd8065aec6a1299ad3 /crypto | |
parent | b37871cd0a4290cbaba9464856a7f17f26d1c30a (diff) |
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)
Diffstat (limited to 'crypto')
-rw-r--r-- | crypto/dh/dh_check.c | 12 | ||||
-rw-r--r-- | crypto/dh/dh_err.c | 3 | ||||
-rw-r--r-- | crypto/dh/dh_key.c | 12 | ||||
-rw-r--r-- | crypto/err/openssl.txt | 1 |
4 files changed, 27 insertions, 1 deletions
diff --git a/crypto/dh/dh_check.c b/crypto/dh/dh_check.c index 7ba2beae7f..e20eb62081 100644 --- a/crypto/dh/dh_check.c +++ b/crypto/dh/dh_check.c @@ -249,6 +249,18 @@ int DH_check_pub_key_ex(const DH *dh, const BIGNUM *pub_key) */ 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->params.p) > OPENSSL_DH_CHECK_MAX_MODULUS_BITS) { + ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE); + *ret = DH_MODULUS_TOO_LARGE | DH_CHECK_PUBKEY_INVALID; + return 0; + } + + if (dh->params.q != NULL && BN_ucmp(dh->params.p, dh->params.q) < 0) { + *ret |= DH_CHECK_INVALID_Q_VALUE | DH_CHECK_PUBKEY_INVALID; + return 1; + } + return ossl_ffc_validate_public_key(&dh->params, pub_key, ret); } diff --git a/crypto/dh/dh_err.c b/crypto/dh/dh_err.c index 4152397426..f76ac0dd14 100644 --- a/crypto/dh/dh_err.c +++ b/crypto/dh/dh_err.c @@ -1,6 +1,6 @@ /* * Generated by util/mkerr.pl DO NOT EDIT - * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy @@ -54,6 +54,7 @@ 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 d84ea99241..afc49f5cdc 100644 --- a/crypto/dh/dh_key.c +++ b/crypto/dh/dh_key.c @@ -49,6 +49,12 @@ int ossl_dh_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) goto err; } + if (dh->params.q != NULL + && BN_num_bits(dh->params.q) > OPENSSL_DH_MAX_MODULUS_BITS) { + ERR_raise(ERR_LIB_DH, DH_R_Q_TOO_LARGE); + goto err; + } + if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS) { ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_SMALL); return 0; @@ -267,6 +273,12 @@ static int generate_key(DH *dh) return 0; } + if (dh->params.q != NULL + && BN_num_bits(dh->params.q) > OPENSSL_DH_MAX_MODULUS_BITS) { + ERR_raise(ERR_LIB_DH, DH_R_Q_TOO_LARGE); + return 0; + } + if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS) { ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_SMALL); return 0; diff --git a/crypto/err/openssl.txt b/crypto/err/openssl.txt index e51504b7ab..36de321b74 100644 --- a/crypto/err/openssl.txt +++ b/crypto/err/openssl.txt @@ -500,6 +500,7 @@ 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_FFC_PARAMETERS:114:bad ffc parameters |