/*- * Copyright 2007-2020 The OpenSSL Project Authors. All Rights Reserved. * Copyright Nokia 2007-2019 * Copyright Siemens AG 2015-2019 * * 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 * * CRMF implementation by Martin Peylo, Miikka Viljanen, and David von Oheimb. */ #include #include #include #include "crmf_local.h" /* explicit #includes not strictly needed since implied by the above: */ #include #include #include #include #include #include /*- * creates and initializes OSSL_CRMF_PBMPARAMETER (section 4.4) * |slen| SHOULD be > 8 (16 is common) * |owfnid| e.g., NID_sha256 * |itercnt| MUST be > 100 (500 is common) * |macnid| e.g., NID_hmac_sha1 * returns pointer to OSSL_CRMF_PBMPARAMETER on success, NULL on error */ OSSL_CRMF_PBMPARAMETER *OSSL_CRMF_pbmp_new(size_t slen, int owfnid, int itercnt, int macnid) { OSSL_CRMF_PBMPARAMETER *pbm = NULL; unsigned char *salt = NULL; if ((pbm = OSSL_CRMF_PBMPARAMETER_new()) == NULL) goto err; /* * salt contains a randomly generated value used in computing the key * of the MAC process. The salt SHOULD be at least 8 octets (64 * bits) long. */ if ((salt = OPENSSL_malloc(slen)) == NULL) goto err; if (RAND_bytes(salt, (int)slen) <= 0) { CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_FAILURE_OBTAINING_RANDOM); goto err; } if (!ASN1_OCTET_STRING_set(pbm->salt, salt, (int)slen)) goto err; /* * owf identifies the hash algorithm and associated parameters used to * compute the key used in the MAC process. All implementations MUST * support SHA-1. */ if (!X509_ALGOR_set0(pbm->owf, OBJ_nid2obj(owfnid), V_ASN1_UNDEF, NULL)) { CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_SETTING_OWF_ALGOR_FAILURE); goto err; } /* * iterationCount identifies the number of times the hash is applied * during the key computation process. The iterationCount MUST be a * minimum of 100. Many people suggest using values as high as 1000 * iterations as the minimum value. The trade off here is between * protection of the password from attacks and the time spent by the * server processing all of the different iterations in deriving * passwords. Hashing is generally considered a cheap operation but * this may not be true with all hash functions in the future. */ if (itercnt < 100) { CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_ITERATIONCOUNT_BELOW_100); goto err; } if (!ASN1_INTEGER_set(pbm->iterationCount, itercnt)) { CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_CRMFERROR); goto err; } /* * mac identifies the algorithm and associated parameters of the MAC * function to be used. All implementations MUST support HMAC-SHA1 [HMAC]. * All implementations SHOULD support DES-MAC and Triple-DES-MAC [PKCS11]. */ if (!X509_ALGOR_set0(pbm->mac, OBJ_nid2obj(macnid), V_ASN1_UNDEF, NULL)) { CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_SETTING_MAC_ALGOR_FAILURE); goto err; } OPENSSL_free(salt); return pbm; err: OPENSSL_free(salt); OSSL_CRMF_PBMPARAMETER_free(pbm); return NULL; } /*- * calculates the PBM based on the settings of the given OSSL_CRMF_PBMPARAMETER * |pbmp| identifies the algorithms, salt to use * |msg| message to apply the PBM for * |msglen| length of the message * |sec| key to use * |seclen| length of the key * |mac| pointer to the computed mac, will be set on success * |maclen| if not NULL, will set variable to the length of the mac on success * returns 1 on success, 0 on error */ int OSSL_CRMF_pbm_new(const OSSL_CRMF_PBMPARAMETER *pbmp, const unsigned char *msg, size_t msglen, const unsigned char *sec, size_t seclen, unsigned char **out, size_t *outlen) { int mac_nid, hmac_md_nid = NID_undef; const char *mdname = NULL; const EVP_MD *m = NULL; EVP_MD_CTX *ctx = NULL; unsigned char basekey[EVP_MAX_MD_SIZE]; unsigned int bklen = EVP_MAX_MD_SIZE; int64_t iterations; unsigned char *mac_res = 0; int ok = 0; EVP_MAC *mac = NULL; EVP_MAC_CTX *mctx = NULL; OSSL_PARAM macparams[3] = {OSSL_PARAM_END, OSSL_PARAM_END, OSSL_PARAM_END}; if (out == NULL || pbmp == NULL || pbmp->mac == NULL || pbmp->mac->algorithm == NULL || msg == NULL || sec == NULL) { CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, CRMF_R_NULL_ARGUMENT); goto err; } if ((mac_res = OPENSSL_malloc(EVP_MAX_MD_SIZE)) == NULL) goto err; /* * owf identifies the hash algorithm and associated parameters used to * compute the key used in the MAC process. All implementations MUST * support SHA-1. */ if ((m = EVP_get_digestbyobj(pbmp->owf->algorithm)) == NULL) { CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, CRMF_R_UNSUPPORTED_ALGORITHM); goto err; } if ((ctx = EVP_MD_CTX_new()) == NULL) goto err; /* compute the basekey of the salted secret */ if (!EVP_DigestInit_ex(ctx, m, NULL)) goto err; /* first the secret */ if (!EVP_DigestUpdate(ctx, sec, seclen)) goto err; /* then the salt */ if (!EVP_DigestUpdate(ctx, pbmp->salt->data, pbmp->salt->length)) goto err; if (!EVP_DigestFinal_ex(ctx, basekey, &bklen)) goto err; if (!ASN1_INTEGER_get_int64(&iterations, pbmp->iterationCount) || iterations < 100 /* min from RFC */ || iterations > OSSL_CRMF_PBM_MAX_ITERATION_COUNT) { CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, CRMF_R_BAD_PBM_ITERATIONCOUNT); goto err; } /* the first iteration was already done above */ while (--iterations > 0) { if (!EVP_DigestInit_ex(ctx, m, NULL)) goto err; if (!EVP_DigestUpdate(ctx, basekey, bklen)) goto err; if (!EVP_DigestFinal_ex(ctx, basekey, &bklen)) goto err; } /* * mac identifies the algorithm and associated parameters of the MAC * function to be used. All implementations MUST support HMAC-SHA1 [HMAC]. * All implementations SHOULD support DES-MAC and Triple-DES-MAC [PKCS11]. */ mac_nid = OBJ_obj2nid(pbmp->mac->algorithm); if (!EVP_PBE_find(EVP_PBE_TYPE_PRF, mac_nid, NULL, &hmac_md_nid, NULL) || (mdname = OBJ_nid2sn(hmac_md_nid)) == NULL) { CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, CRMF_R_UNSUPPORTED_ALGORITHM); goto err; } macparams[0] = OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_DIGEST, (char *)mdname, 0); macparams[1] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, basekey, bklen); if ((mac = EVP_MAC_fetch(NULL, "HMAC", NULL)) == NULL || (mctx = EVP_MAC_CTX_new(mac)) == NULL || !EVP_MAC_CTX_set_params(mctx, macparams) || !EVP_MAC_init(mctx) || !EVP_MAC_update(mctx, msg, msglen) || !EVP_MAC_final(mctx, mac_res, outlen, EVP_MAX_MD_SIZE)) goto err; ok = 1; err: /* cleanup */ OPENSSL_cleanse(basekey, bklen); EVP_MAC_CTX_free(mctx); EVP_MAC_free(mac); EVP_MD_CTX_free(ctx); if (ok == 1) { *out = mac_res; return 1; } OPENSSL_free(mac_res); if (pbmp != NULL && pbmp->mac != NULL) { char buf[128]; if (OBJ_obj2txt(buf, sizeof(buf), pbmp->mac->algorithm, 0)) ERR_add_error_data(1, buf); } return 0; }