crypto/rsa/rsa_backend.c

   1 /*
   2  * Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <string.h>
  11 #include <openssl/core_names.h>
  12 #include <openssl/params.h>
  13 #include <openssl/evp.h>
  14 #include "internal/sizes.h"
  15 #include "internal/param_build_set.h"
  16 #include "crypto/rsa.h"
  17
  18 #include "e_os.h"                /* strcasecmp for Windows() */
  19
  20 /*
  21  * The intention with the "backend" source file is to offer backend support
  22  * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
  23  * implementations alike.
  24  */
  25
  26 DEFINE_STACK_OF(BIGNUM)
  27
  28 static int collect_numbers(STACK_OF(BIGNUM) *numbers,
  29                            const OSSL_PARAM params[], const char *names[])
  30 {
  31     const OSSL_PARAM *p = NULL;
  32     int i;
  33
  34     if (numbers == NULL)
  35         return 0;
  36
  37     for (i = 0; names[i] != NULL; i++){
  38         p = OSSL_PARAM_locate_const(params, names[i]);
  39         if (p != NULL) {
  40             BIGNUM *tmp = NULL;
  41
  42             if (!OSSL_PARAM_get_BN(p, &tmp)
  43                 || sk_BIGNUM_push(numbers, tmp) == 0)
  44                 return 0;
  45         }
  46     }
  47
  48     return 1;
  49 }
  50
  51 int ossl_rsa_fromdata(RSA *rsa, const OSSL_PARAM params[])
  52 {
  53     const OSSL_PARAM *param_n, *param_e,  *param_d;
  54     BIGNUM *n = NULL, *e = NULL, *d = NULL;
  55     STACK_OF(BIGNUM) *factors = NULL, *exps = NULL, *coeffs = NULL;
  56     int is_private = 0;
  57
  58     if (rsa == NULL)
  59         return 0;
  60
  61     param_n = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_N);
  62     param_e = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_E);
  63     param_d = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_D);
  64
  65     if ((param_n != NULL && !OSSL_PARAM_get_BN(param_n, &n))
  66         || (param_e != NULL && !OSSL_PARAM_get_BN(param_e, &e))
  67         || (param_d != NULL && !OSSL_PARAM_get_BN(param_d, &d)))
  68         goto err;
  69
  70     is_private = (d != NULL);
  71
  72     if (!RSA_set0_key(rsa, n, e, d))
  73         goto err;
  74     n = e = d = NULL;
  75
  76     if (is_private) {
  77         if (!collect_numbers(factors = sk_BIGNUM_new_null(), params,
  78                              ossl_rsa_mp_factor_names)
  79             || !collect_numbers(exps = sk_BIGNUM_new_null(), params,
  80                                 ossl_rsa_mp_exp_names)
  81             || !collect_numbers(coeffs = sk_BIGNUM_new_null(), params,
  82                                 ossl_rsa_mp_coeff_names))
  83             goto err;
  84
  85         /* It's ok if this private key just has n, e and d */
  86         if (sk_BIGNUM_num(factors) != 0
  87             && !ossl_rsa_set0_all_params(rsa, factors, exps, coeffs))
  88             goto err;
  89     }
  90
  91
  92     sk_BIGNUM_free(factors);
  93     sk_BIGNUM_free(exps);
  94     sk_BIGNUM_free(coeffs);
  95     return 1;
  96
  97  err:
  98     BN_free(n);
  99     BN_free(e);
 100     BN_free(d);
 101     sk_BIGNUM_pop_free(factors, BN_free);
 102     sk_BIGNUM_pop_free(exps, BN_free);
 103     sk_BIGNUM_pop_free(coeffs, BN_free);
 104     return 0;
 105 }
 106
 107 DEFINE_SPECIAL_STACK_OF_CONST(BIGNUM_const, BIGNUM)
 108
 109 int ossl_rsa_todata(RSA *rsa, OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
 110 {
 111     int ret = 0;
 112     const BIGNUM *rsa_d = NULL, *rsa_n = NULL, *rsa_e = NULL;
 113     STACK_OF(BIGNUM_const) *factors = sk_BIGNUM_const_new_null();
 114     STACK_OF(BIGNUM_const) *exps = sk_BIGNUM_const_new_null();
 115     STACK_OF(BIGNUM_const) *coeffs = sk_BIGNUM_const_new_null();
 116
 117     if (rsa == NULL || factors == NULL || exps == NULL || coeffs == NULL)
 118         goto err;
 119
 120     RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
 121     ossl_rsa_get0_all_params(rsa, factors, exps, coeffs);
 122
 123     if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_N, rsa_n)
 124         || !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_E, rsa_e))
 125         goto err;
 126
 127     /* Check private key data integrity */
 128     if (rsa_d != NULL) {
 129         int numprimes = sk_BIGNUM_const_num(factors);
 130         int numexps = sk_BIGNUM_const_num(exps);
 131         int numcoeffs = sk_BIGNUM_const_num(coeffs);
 132
 133         /*
 134          * It's permissible to have zero primes, i.e. no CRT params.
 135          * Otherwise, there must be at least two, as many exponents,
 136          * and one coefficient less.
 137          */
 138         if (numprimes != 0
 139             && (numprimes < 2 || numexps < 2 || numcoeffs < 1))
 140             goto err;
 141
 142         if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_D,
 143                                      rsa_d)
 144             || !ossl_param_build_set_multi_key_bn(bld, params,
 145                                                   ossl_rsa_mp_factor_names,
 146                                                   factors)
 147             || !ossl_param_build_set_multi_key_bn(bld, params,
 148                                                   ossl_rsa_mp_exp_names, exps)
 149             || !ossl_param_build_set_multi_key_bn(bld, params,
 150                                                   ossl_rsa_mp_coeff_names,
 151                                                   coeffs))
 152         goto err;
 153     }
 154
 155 #if defined(FIPS_MODULE) && !defined(OPENSSL_NO_ACVP_TESTS)
 156     /* The acvp test results are not meant for export so check for bld == NULL */
 157     if (bld == NULL)
 158         rsa_acvp_test_get_params(rsa, params);
 159 #endif
 160     ret = 1;
 161  err:
 162     sk_BIGNUM_const_free(factors);
 163     sk_BIGNUM_const_free(exps);
 164     sk_BIGNUM_const_free(coeffs);
 165     return ret;
 166 }
 167
 168 int ossl_rsa_pss_params_30_todata(const RSA_PSS_PARAMS_30 *pss,
 169                                   OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
 170 {
 171     if (!ossl_rsa_pss_params_30_is_unrestricted(pss)) {
 172         int hashalg_nid = ossl_rsa_pss_params_30_hashalg(pss);
 173         int maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(pss);
 174         int maskgenhashalg_nid = ossl_rsa_pss_params_30_maskgenhashalg(pss);
 175         int saltlen = ossl_rsa_pss_params_30_saltlen(pss);
 176         int default_hashalg_nid = ossl_rsa_pss_params_30_hashalg(NULL);
 177         int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
 178         int default_maskgenhashalg_nid =
 179                 ossl_rsa_pss_params_30_maskgenhashalg(NULL);
 180         const char *mdname =
 181             (hashalg_nid == default_hashalg_nid
 182              ? NULL : ossl_rsa_oaeppss_nid2name(hashalg_nid));
 183         const char *mgfname =
 184             (maskgenalg_nid == default_maskgenalg_nid
 185              ? NULL : ossl_rsa_oaeppss_nid2name(maskgenalg_nid));
 186         const char *mgf1mdname =
 187             (maskgenhashalg_nid == default_maskgenhashalg_nid
 188              ? NULL : ossl_rsa_oaeppss_nid2name(maskgenhashalg_nid));
 189         const char *key_md = OSSL_PKEY_PARAM_RSA_DIGEST;
 190         const char *key_mgf = OSSL_PKEY_PARAM_RSA_MASKGENFUNC;
 191         const char *key_mgf1_md = OSSL_PKEY_PARAM_RSA_MGF1_DIGEST;
 192         const char *key_saltlen = OSSL_PKEY_PARAM_RSA_PSS_SALTLEN;
 193
 194         /*
 195          * To ensure that the key isn't seen as unrestricted by the recipient,
 196          * we make sure that at least one PSS-related parameter is passed, even
 197          * if it has a default value; saltlen.
 198          */
 199         if ((mdname != NULL
 200              && !ossl_param_build_set_utf8_string(bld, params, key_md, mdname))
 201             || (mgfname != NULL
 202                 && !ossl_param_build_set_utf8_string(bld, params,
 203                                                      key_mgf, mgfname))
 204             || (mgf1mdname != NULL
 205                 && !ossl_param_build_set_utf8_string(bld, params,
 206                                                      key_mgf1_md, mgf1mdname))
 207             || (!ossl_param_build_set_int(bld, params, key_saltlen, saltlen)))
 208             return 0;
 209     }
 210     return 1;
 211 }
 212
 213 int ossl_rsa_pss_params_30_fromdata(RSA_PSS_PARAMS_30 *pss_params,
 214                                     const OSSL_PARAM params[],
 215                                     OPENSSL_CTX *libctx)
 216 {
 217     const OSSL_PARAM *param_md, *param_mgf, *param_mgf1md,  *param_saltlen;
 218     const OSSL_PARAM *param_propq;
 219     const char *propq = NULL;
 220     EVP_MD *md = NULL, *mgf1md = NULL;
 221     int saltlen;
 222     int ret = 0;
 223
 224     if (pss_params == NULL)
 225         return 0;
 226     param_propq =
 227         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST_PROPS);
 228     param_md =
 229         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST);
 230     param_mgf =
 231         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MASKGENFUNC);
 232     param_mgf1md =
 233         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MGF1_DIGEST);
 234     param_saltlen =
 235         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_PSS_SALTLEN);
 236
 237     if (param_propq != NULL) {
 238         if (param_propq->data_type == OSSL_PARAM_UTF8_STRING)
 239             propq = param_propq->data;
 240     }
 241     /*
 242      * If we get any of the parameters, we know we have at least some
 243      * restrictions, so we start by setting default values, and let each
 244      * parameter override their specific restriction data.
 245      */
 246     if (param_md != NULL || param_mgf != NULL || param_mgf1md != NULL
 247         || param_saltlen != NULL)
 248         if (!ossl_rsa_pss_params_30_set_defaults(pss_params))
 249             return 0;
 250
 251     if (param_mgf != NULL) {
 252         int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
 253         const char *mgfname = NULL;
 254
 255         if (param_mgf->data_type == OSSL_PARAM_UTF8_STRING)
 256             mgfname = param_mgf->data;
 257         else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgfname))
 258             return 0;
 259
 260         /* TODO Revisit this if / when a new MGF algorithm appears */
 261         if (strcasecmp(param_mgf->data,
 262                        ossl_rsa_mgf_nid2name(default_maskgenalg_nid)) != 0)
 263             return 0;
 264     }
 265
 266     /*
 267      * We're only interested in the NIDs that correspond to the MDs, so the
 268      * exact propquery is unimportant in the EVP_MD_fetch() calls below.
 269      */
 270
 271     if (param_md != NULL) {
 272         const char *mdname = NULL;
 273
 274         if (param_md->data_type == OSSL_PARAM_UTF8_STRING)
 275             mdname = param_md->data;
 276         else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mdname))
 277             goto err;
 278
 279         if ((md = EVP_MD_fetch(libctx, mdname, propq)) == NULL
 280             || !ossl_rsa_pss_params_30_set_hashalg(pss_params,
 281                                                    ossl_rsa_oaeppss_md2nid(md)))
 282             goto err;
 283     }
 284
 285     if (param_mgf1md != NULL) {
 286         const char *mgf1mdname = NULL;
 287
 288         if (param_mgf1md->data_type == OSSL_PARAM_UTF8_STRING)
 289             mgf1mdname = param_mgf1md->data;
 290         else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgf1mdname))
 291             goto err;
 292
 293         if ((mgf1md = EVP_MD_fetch(libctx, mgf1mdname, propq)) == NULL
 294             || !ossl_rsa_pss_params_30_set_maskgenhashalg(
 295                     pss_params, ossl_rsa_oaeppss_md2nid(mgf1md)))
 296             goto err;
 297     }
 298
 299     if (param_saltlen != NULL) {
 300         if (!OSSL_PARAM_get_int(param_saltlen, &saltlen)
 301             || !ossl_rsa_pss_params_30_set_saltlen(pss_params, saltlen))
 302             goto err;
 303     }
 304
 305     ret = 1;
 306
 307  err:
 308     EVP_MD_free(md);
 309     EVP_MD_free(mgf1md);
 310     return ret;
 311 }