/* * Copyright 1995-2024 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 * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ /* * DSA low level APIs are deprecated for public use, but still ok for * internal use. */ #include "internal/deprecated.h" #include #include "internal/cryptlib.h" #include #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); else /* * Do full FFC domain params validation according to FIPS-186-4 * - always in FIPS_MODULE * - only if possible (i.e., seed is set) in default provider */ return ossl_ffc_params_full_validate(dsa->libctx, &dsa->params, FFC_PARAM_TYPE_DSA, ret); } /* * See SP800-56Ar3 Section 5.6.2.3.1 : FFC Full public key validation. */ 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; } /* * See SP800-56Ar3 Section 5.6.2.3.1 : FFC Partial public key validation. * To only be used with ephemeral FFC public keys generated using the approved * safe-prime groups. */ 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; } int ossl_dsa_check_priv_key(const DSA *dsa, const BIGNUM *priv_key, int *ret) { *ret = 0; if (!dsa_precheck_params(dsa, ret)) return 0; return ossl_ffc_validate_private_key(dsa->params.q, priv_key, ret); } /* * FFC pairwise check from SP800-56A R3. * Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency */ int ossl_dsa_check_pairwise(const DSA *dsa) { int ret = 0; BN_CTX *ctx = NULL; BIGNUM *pub_key = NULL; if (!dsa_precheck_params(dsa, &ret)) return 0; if (dsa->params.g == NULL || dsa->priv_key == NULL || dsa->pub_key == NULL) return 0; ctx = BN_CTX_new_ex(dsa->libctx); if (ctx == NULL) goto err; pub_key = BN_new(); if (pub_key == NULL) goto err; /* recalculate the public key = (g ^ priv) mod p */ if (!ossl_dsa_generate_public_key(ctx, dsa, dsa->priv_key, pub_key)) goto err; /* check it matches the existing public_key */ ret = BN_cmp(pub_key, dsa->pub_key) == 0; err: BN_free(pub_key); BN_CTX_free(ctx); return ret; }