crypto/crmf/crmf_pbm.c

   1 /*-
   2  * Copyright 2007-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright Nokia 2007-2018
   4  * Copyright Siemens AG 2015-2018
   5  *
   6  * Licensed under the OpenSSL license (the "License").  You may not use
   7  * this file except in compliance with the License.  You can obtain a copy
   8  * in the file LICENSE in the source distribution or at
   9  * https://www.openssl.org/source/license.html
  10  *
  11  * CRMF implementation by Martin Peylo, Miikka Viljanen, and David von Oheimb.
  12  */
  13
  14
  15 #include <openssl/rand.h>
  16 #include <openssl/evp.h>
  17
  18 #include "crmf_int.h"
  19
  20 /* explicit #includes not strictly needed since implied by the above: */
  21 #include <openssl/asn1t.h>
  22 #include <openssl/crmf.h>
  23 #include <openssl/err.h>
  24 #include <openssl/evp.h>
  25
  26 /*-
  27  * creates and initializes OSSL_CRMF_PBMPARAMETER (section 4.4)
  28  * |slen| SHOULD be > 8    (16 is common)
  29  * |owfnid| e.g., NID_sha256
  30  * |itercnt| MUST be > 100 (500 is common)
  31  * |macnid| e.g., NID_hmac_sha1
  32  * returns pointer to OSSL_CRMF_PBMPARAMETER on success, NULL on error
  33  */
  34 OSSL_CRMF_PBMPARAMETER *OSSL_CRMF_pbmp_new(size_t slen, int owfnid,
  35                                            int itercnt, int macnid)
  36 {
  37     OSSL_CRMF_PBMPARAMETER *pbm = NULL;
  38     unsigned char *salt = NULL;
  39
  40     if ((pbm = OSSL_CRMF_PBMPARAMETER_new()) == NULL) {
  41         CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, ERR_R_MALLOC_FAILURE);
  42         goto err;
  43     }
  44
  45     /*
  46      * salt contains a randomly generated value used in computing the key
  47      * of the MAC process.  The salt SHOULD be at least 8 octets (64
  48      * bits) long.
  49      */
  50     if ((salt = OPENSSL_malloc(slen)) == NULL) {
  51         CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, ERR_R_MALLOC_FAILURE);
  52         goto err;
  53     }
  54     if (RAND_bytes(salt, (int)slen) <= 0) {
  55         CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_FAILURE_OBTAINING_RANDOM);
  56         goto err;
  57     }
  58     if (!ASN1_OCTET_STRING_set(pbm->salt, salt, (int)slen))
  59         goto err;
  60
  61     /*
  62      * owf identifies the hash algorithm and associated parameters used to
  63      * compute the key used in the MAC process.  All implementations MUST
  64      * support SHA-1.
  65      */
  66     if (!X509_ALGOR_set0(pbm->owf, OBJ_nid2obj(owfnid), V_ASN1_UNDEF, NULL)) {
  67         CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_SETTING_OWF_ALGOR_FAILURE);
  68         goto err;
  69     }
  70
  71     /*
  72      * iterationCount identifies the number of times the hash is applied
  73      * during the key computation process.  The iterationCount MUST be a
  74      * minimum of 100.      Many people suggest using values as high as 1000
  75      * iterations as the minimum value.  The trade off here is between
  76      * protection of the password from attacks and the time spent by the
  77      * server processing all of the different iterations in deriving
  78      * passwords.  Hashing is generally considered a cheap operation but
  79      * this may not be true with all hash functions in the future.
  80      */
  81     if (itercnt < 100) {
  82         CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_ITERATIONCOUNT_BELOW_100);
  83         goto err;
  84     }
  85
  86     if (!ASN1_INTEGER_set(pbm->iterationCount, itercnt)) {
  87         CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_CRMFERROR);
  88         goto err;
  89     }
  90
  91     /*
  92      * mac identifies the algorithm and associated parameters of the MAC
  93      * function to be used.  All implementations MUST support HMAC-SHA1 [HMAC].
  94      * All implementations SHOULD support DES-MAC and Triple-DES-MAC [PKCS11].
  95      */
  96     if (!X509_ALGOR_set0(pbm->mac, OBJ_nid2obj(macnid), V_ASN1_UNDEF, NULL)) {
  97         CRMFerr(CRMF_F_OSSL_CRMF_PBMP_NEW, CRMF_R_SETTING_MAC_ALGOR_FAILURE);
  98         goto err;
  99     }
 100
 101     OPENSSL_free(salt);
 102     return pbm;
 103  err:
 104     OPENSSL_free(salt);
 105     OSSL_CRMF_PBMPARAMETER_free(pbm);
 106     return NULL;
 107 }
 108
 109 /*-
 110  * calculates the PBM based on the settings of the given OSSL_CRMF_PBMPARAMETER
 111  * |pbmp| identifies the algorithms, salt to use
 112  * |msg| message to apply the PBM for
 113  * |msglen| length of the message
 114  * |sec| key to use
 115  * |seclen| length of the key
 116  * |mac| pointer to the computed mac, will be set on success
 117  * |maclen| if not NULL, will set variable to the length of the mac on success
 118  * returns 1 on success, 0 on error
 119  */
 120 int OSSL_CRMF_pbm_new(const OSSL_CRMF_PBMPARAMETER *pbmp,
 121                       const unsigned char *msg, size_t msglen,
 122                       const unsigned char *sec, size_t seclen,
 123                       unsigned char **mac, size_t *maclen)
 124 {
 125     int mac_nid, hmac_md_nid = NID_undef;
 126     const EVP_MD *m = NULL;
 127     EVP_MD_CTX *ctx = NULL;
 128     unsigned char basekey[EVP_MAX_MD_SIZE];
 129     unsigned int bklen = EVP_MAX_MD_SIZE;
 130     int64_t iterations;
 131     unsigned char *mac_res = 0;
 132     int ok = 0;
 133     EVP_MAC_CTX *mctx = NULL;
 134
 135     if (mac == NULL || pbmp == NULL || pbmp->mac == NULL
 136             || pbmp->mac->algorithm == NULL || msg == NULL || sec == NULL) {
 137         CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, CRMF_R_NULL_ARGUMENT);
 138         goto err;
 139     }
 140     if ((mac_res = OPENSSL_malloc(EVP_MAX_MD_SIZE)) == NULL) {
 141         CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, ERR_R_MALLOC_FAILURE);
 142         goto err;
 143     }
 144
 145     /*
 146      * owf identifies the hash algorithm and associated parameters used to
 147      * compute the key used in the MAC process.  All implementations MUST
 148      * support SHA-1.
 149      */
 150     if ((m = EVP_get_digestbyobj(pbmp->owf->algorithm)) == NULL) {
 151         CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, CRMF_R_UNSUPPORTED_ALGORITHM);
 152         goto err;
 153     }
 154
 155     if ((ctx = EVP_MD_CTX_new()) == NULL) {
 156         CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, ERR_R_MALLOC_FAILURE);
 157         goto err;
 158     }
 159
 160     /* compute the basekey of the salted secret */
 161     if (!EVP_DigestInit_ex(ctx, m, NULL))
 162         goto err;
 163     /* first the secret */
 164     if (!EVP_DigestUpdate(ctx, sec, seclen))
 165         goto err;
 166     /* then the salt */
 167     if (!EVP_DigestUpdate(ctx, pbmp->salt->data, pbmp->salt->length))
 168         goto err;
 169     if (!EVP_DigestFinal_ex(ctx, basekey, &bklen))
 170         goto err;
 171     if (!ASN1_INTEGER_get_int64(&iterations, pbmp->iterationCount)
 172             || iterations < 100 /* min from RFC */
 173             || iterations > OSSL_CRMF_PBM_MAX_ITERATION_COUNT) {
 174         CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, CRMF_R_BAD_PBM_ITERATIONCOUNT);
 175         goto err;
 176     }
 177
 178     /* the first iteration was already done above */
 179     while (--iterations > 0) {
 180         if (!EVP_DigestInit_ex(ctx, m, NULL))
 181             goto err;
 182         if (!EVP_DigestUpdate(ctx, basekey, bklen))
 183             goto err;
 184         if (!EVP_DigestFinal_ex(ctx, basekey, &bklen))
 185             goto err;
 186     }
 187
 188     /*
 189      * mac identifies the algorithm and associated parameters of the MAC
 190      * function to be used.  All implementations MUST support HMAC-SHA1 [HMAC].
 191      * All implementations SHOULD support DES-MAC and Triple-DES-MAC [PKCS11].
 192      */
 193     mac_nid = OBJ_obj2nid(pbmp->mac->algorithm);
 194
 195     if (!EVP_PBE_find(EVP_PBE_TYPE_PRF, mac_nid, NULL, &hmac_md_nid, NULL)
 196             || ((m = EVP_get_digestbynid(hmac_md_nid)) == NULL)) {
 197         CRMFerr(CRMF_F_OSSL_CRMF_PBM_NEW, CRMF_R_UNSUPPORTED_ALGORITHM);
 198         goto err;
 199     }
 200
 201     if ((mctx = EVP_MAC_CTX_new(EVP_get_macbyname("HMAC"))) == NULL
 202             || EVP_MAC_ctrl(mctx, EVP_MAC_CTRL_SET_MD, m) <= 0
 203             || EVP_MAC_ctrl(mctx, EVP_MAC_CTRL_SET_KEY, basekey, bklen) <= 0
 204             || !EVP_MAC_init(mctx)
 205             || !EVP_MAC_update(mctx, msg, msglen)
 206             || !EVP_MAC_final(mctx, mac_res, maclen))
 207         goto err;
 208
 209     ok = 1;
 210
 211  err:
 212     /* cleanup */
 213     OPENSSL_cleanse(basekey, bklen);
 214     EVP_MAC_CTX_free(mctx);
 215     EVP_MD_CTX_free(ctx);
 216
 217     if (ok == 1) {
 218         *mac = mac_res;
 219         return 1;
 220     }
 221
 222     OPENSSL_free(mac_res);
 223
 224     if (pbmp != NULL && pbmp->mac != NULL) {
 225         char buf[128];
 226
 227         if (OBJ_obj2txt(buf, sizeof(buf), pbmp->mac->algorithm, 0))
 228             ERR_add_error_data(1, buf);
 229     }
 230     return 0;
 231 }