From 3559e868e58005d15c6013a0c1fd832e51c73397 Mon Sep 17 00:00:00 2001 From: Tomas Mraz Date: Wed, 8 May 2024 15:23:45 +0200 Subject: Check DSA parameters for excessive sizes before validating This avoids overly long computation of various validation checks. Fixes CVE-2024-4603 Reviewed-by: Paul Dale Reviewed-by: Matt Caswell Reviewed-by: Neil Horman Reviewed-by: Shane Lontis (Merged from https://github.com/openssl/openssl/pull/24346) (cherry picked from commit 85ccbab216da245cf9a6503dd327072f21950d9b) --- crypto/dsa/dsa_check.c | 44 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 40 insertions(+), 4 deletions(-) (limited to 'crypto/dsa/dsa_check.c') diff --git a/crypto/dsa/dsa_check.c b/crypto/dsa/dsa_check.c index fb0e9129a2..122449a7bf 100644 --- a/crypto/dsa/dsa_check.c +++ b/crypto/dsa/dsa_check.c @@ -19,8 +19,34 @@ #include "dsa_local.h" #include "crypto/dsa.h" +static int dsa_precheck_params(const DSA *dsa, int *ret) +{ + if (dsa->params.p == NULL || dsa->params.q == NULL) { + ERR_raise(ERR_LIB_DSA, DSA_R_BAD_FFC_PARAMETERS); + *ret = FFC_CHECK_INVALID_PQ; + return 0; + } + + if (BN_num_bits(dsa->params.p) > OPENSSL_DSA_MAX_MODULUS_BITS) { + ERR_raise(ERR_LIB_DSA, DSA_R_MODULUS_TOO_LARGE); + *ret = FFC_CHECK_INVALID_PQ; + return 0; + } + + if (BN_num_bits(dsa->params.q) >= BN_num_bits(dsa->params.p)) { + ERR_raise(ERR_LIB_DSA, DSA_R_BAD_Q_VALUE); + *ret = FFC_CHECK_INVALID_PQ; + return 0; + } + + return 1; +} + int ossl_dsa_check_params(const DSA *dsa, int checktype, int *ret) { + if (!dsa_precheck_params(dsa, ret)) + return 0; + if (checktype == OSSL_KEYMGMT_VALIDATE_QUICK_CHECK) return ossl_ffc_params_simple_validate(dsa->libctx, &dsa->params, FFC_PARAM_TYPE_DSA, ret); @@ -39,6 +65,9 @@ int ossl_dsa_check_params(const DSA *dsa, int checktype, int *ret) */ int ossl_dsa_check_pub_key(const DSA *dsa, const BIGNUM *pub_key, int *ret) { + if (!dsa_precheck_params(dsa, ret)) + return 0; + return ossl_ffc_validate_public_key(&dsa->params, pub_key, ret) && *ret == 0; } @@ -50,6 +79,9 @@ int ossl_dsa_check_pub_key(const DSA *dsa, const BIGNUM *pub_key, int *ret) */ int ossl_dsa_check_pub_key_partial(const DSA *dsa, const BIGNUM *pub_key, int *ret) { + if (!dsa_precheck_params(dsa, ret)) + return 0; + return ossl_ffc_validate_public_key_partial(&dsa->params, pub_key, ret) && *ret == 0; } @@ -58,8 +90,10 @@ int ossl_dsa_check_priv_key(const DSA *dsa, const BIGNUM *priv_key, int *ret) { *ret = 0; - return (dsa->params.q != NULL - && ossl_ffc_validate_private_key(dsa->params.q, priv_key, ret)); + if (!dsa_precheck_params(dsa, ret)) + return 0; + + return ossl_ffc_validate_private_key(dsa->params.q, priv_key, ret); } /* @@ -72,8 +106,10 @@ int ossl_dsa_check_pairwise(const DSA *dsa) BN_CTX *ctx = NULL; BIGNUM *pub_key = NULL; - if (dsa->params.p == NULL - || dsa->params.g == NULL + if (!dsa_precheck_params(dsa, &ret)) + return 0; + + if (dsa->params.g == NULL || dsa->priv_key == NULL || dsa->pub_key == NULL) return 0; -- cgit v1.2.3