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 /*
  11  * RSA low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <string.h>
  17 #include <openssl/core_names.h>
  18 #include <openssl/params.h>
  19 #include <openssl/evp.h>
  20 #include "internal/sizes.h"
  21 #include "internal/param_build_set.h"
  22 #include "crypto/rsa.h"
  23
  24 #include "e_os.h"                /* strcasecmp for Windows() */
  25
  26 /*
  27  * The intention with the "backend" source file is to offer backend support
  28  * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
  29  * implementations alike.
  30  */
  31
  32 DEFINE_STACK_OF(BIGNUM)
  33
  34 static int collect_numbers(STACK_OF(BIGNUM) *numbers,
  35                            const OSSL_PARAM params[], const char *names[])
  36 {
  37     const OSSL_PARAM *p = NULL;
  38     int i;
  39
  40     if (numbers == NULL)
  41         return 0;
  42
  43     for (i = 0; names[i] != NULL; i++){
  44         p = OSSL_PARAM_locate_const(params, names[i]);
  45         if (p != NULL) {
  46             BIGNUM *tmp = NULL;
  47
  48             if (!OSSL_PARAM_get_BN(p, &tmp)
  49                 || sk_BIGNUM_push(numbers, tmp) == 0)
  50                 return 0;
  51         }
  52     }
  53
  54     return 1;
  55 }
  56
  57 int ossl_rsa_fromdata(RSA *rsa, const OSSL_PARAM params[])
  58 {
  59     const OSSL_PARAM *param_n, *param_e,  *param_d;
  60     BIGNUM *n = NULL, *e = NULL, *d = NULL;
  61     STACK_OF(BIGNUM) *factors = NULL, *exps = NULL, *coeffs = NULL;
  62     int is_private = 0;
  63
  64     if (rsa == NULL)
  65         return 0;
  66
  67     param_n = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_N);
  68     param_e = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_E);
  69     param_d = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_D);
  70
  71     if ((param_n != NULL && !OSSL_PARAM_get_BN(param_n, &n))
  72         || (param_e != NULL && !OSSL_PARAM_get_BN(param_e, &e))
  73         || (param_d != NULL && !OSSL_PARAM_get_BN(param_d, &d)))
  74         goto err;
  75
  76     is_private = (d != NULL);
  77
  78     if (!RSA_set0_key(rsa, n, e, d))
  79         goto err;
  80     n = e = d = NULL;
  81
  82     if (is_private) {
  83         if (!collect_numbers(factors = sk_BIGNUM_new_null(), params,
  84                              ossl_rsa_mp_factor_names)
  85             || !collect_numbers(exps = sk_BIGNUM_new_null(), params,
  86                                 ossl_rsa_mp_exp_names)
  87             || !collect_numbers(coeffs = sk_BIGNUM_new_null(), params,
  88                                 ossl_rsa_mp_coeff_names))
  89             goto err;
  90
  91         /* It's ok if this private key just has n, e and d */
  92         if (sk_BIGNUM_num(factors) != 0
  93             && !ossl_rsa_set0_all_params(rsa, factors, exps, coeffs))
  94             goto err;
  95     }
  96
  97
  98     sk_BIGNUM_free(factors);
  99     sk_BIGNUM_free(exps);
 100     sk_BIGNUM_free(coeffs);
 101     return 1;
 102
 103  err:
 104     BN_free(n);
 105     BN_free(e);
 106     BN_free(d);
 107     sk_BIGNUM_pop_free(factors, BN_free);
 108     sk_BIGNUM_pop_free(exps, BN_free);
 109     sk_BIGNUM_pop_free(coeffs, BN_free);
 110     return 0;
 111 }
 112
 113 DEFINE_SPECIAL_STACK_OF_CONST(BIGNUM_const, BIGNUM)
 114
 115 int ossl_rsa_todata(RSA *rsa, OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
 116 {
 117     int ret = 0;
 118     const BIGNUM *rsa_d = NULL, *rsa_n = NULL, *rsa_e = NULL;
 119     STACK_OF(BIGNUM_const) *factors = sk_BIGNUM_const_new_null();
 120     STACK_OF(BIGNUM_const) *exps = sk_BIGNUM_const_new_null();
 121     STACK_OF(BIGNUM_const) *coeffs = sk_BIGNUM_const_new_null();
 122
 123     if (rsa == NULL || factors == NULL || exps == NULL || coeffs == NULL)
 124         goto err;
 125
 126     RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
 127     ossl_rsa_get0_all_params(rsa, factors, exps, coeffs);
 128
 129     if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_N, rsa_n)
 130         || !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_E, rsa_e))
 131         goto err;
 132
 133     /* Check private key data integrity */
 134     if (rsa_d != NULL) {
 135         int numprimes = sk_BIGNUM_const_num(factors);
 136         int numexps = sk_BIGNUM_const_num(exps);
 137         int numcoeffs = sk_BIGNUM_const_num(coeffs);
 138
 139         /*
 140          * It's permissible to have zero primes, i.e. no CRT params.
 141          * Otherwise, there must be at least two, as many exponents,
 142          * and one coefficient less.
 143          */
 144         if (numprimes != 0
 145             && (numprimes < 2 || numexps < 2 || numcoeffs < 1))
 146             goto err;
 147
 148         if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_D,
 149                                      rsa_d)
 150             || !ossl_param_build_set_multi_key_bn(bld, params,
 151                                                   ossl_rsa_mp_factor_names,
 152                                                   factors)
 153             || !ossl_param_build_set_multi_key_bn(bld, params,
 154                                                   ossl_rsa_mp_exp_names, exps)
 155             || !ossl_param_build_set_multi_key_bn(bld, params,
 156                                                   ossl_rsa_mp_coeff_names,
 157                                                   coeffs))
 158         goto err;
 159     }
 160
 161 #if defined(FIPS_MODULE) && !defined(OPENSSL_NO_ACVP_TESTS)
 162     /* The acvp test results are not meant for export so check for bld == NULL */
 163     if (bld == NULL)
 164         rsa_acvp_test_get_params(rsa, params);
 165 #endif
 166     ret = 1;
 167  err:
 168     sk_BIGNUM_const_free(factors);
 169     sk_BIGNUM_const_free(exps);
 170     sk_BIGNUM_const_free(coeffs);
 171     return ret;
 172 }
 173
 174 int ossl_rsa_pss_params_30_todata(const RSA_PSS_PARAMS_30 *pss,
 175                                   OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
 176 {
 177     if (!ossl_rsa_pss_params_30_is_unrestricted(pss)) {
 178         int hashalg_nid = ossl_rsa_pss_params_30_hashalg(pss);
 179         int maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(pss);
 180         int maskgenhashalg_nid = ossl_rsa_pss_params_30_maskgenhashalg(pss);
 181         int saltlen = ossl_rsa_pss_params_30_saltlen(pss);
 182         int default_hashalg_nid = ossl_rsa_pss_params_30_hashalg(NULL);
 183         int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
 184         int default_maskgenhashalg_nid =
 185                 ossl_rsa_pss_params_30_maskgenhashalg(NULL);
 186         const char *mdname =
 187             (hashalg_nid == default_hashalg_nid
 188              ? NULL : ossl_rsa_oaeppss_nid2name(hashalg_nid));
 189         const char *mgfname =
 190             (maskgenalg_nid == default_maskgenalg_nid
 191              ? NULL : ossl_rsa_oaeppss_nid2name(maskgenalg_nid));
 192         const char *mgf1mdname =
 193             (maskgenhashalg_nid == default_maskgenhashalg_nid
 194              ? NULL : ossl_rsa_oaeppss_nid2name(maskgenhashalg_nid));
 195         const char *key_md = OSSL_PKEY_PARAM_RSA_DIGEST;
 196         const char *key_mgf = OSSL_PKEY_PARAM_RSA_MASKGENFUNC;
 197         const char *key_mgf1_md = OSSL_PKEY_PARAM_RSA_MGF1_DIGEST;
 198         const char *key_saltlen = OSSL_PKEY_PARAM_RSA_PSS_SALTLEN;
 199
 200         /*
 201          * To ensure that the key isn't seen as unrestricted by the recipient,
 202          * we make sure that at least one PSS-related parameter is passed, even
 203          * if it has a default value; saltlen.
 204          */
 205         if ((mdname != NULL
 206              && !ossl_param_build_set_utf8_string(bld, params, key_md, mdname))
 207             || (mgfname != NULL
 208                 && !ossl_param_build_set_utf8_string(bld, params,
 209                                                      key_mgf, mgfname))
 210             || (mgf1mdname != NULL
 211                 && !ossl_param_build_set_utf8_string(bld, params,
 212                                                      key_mgf1_md, mgf1mdname))
 213             || (!ossl_param_build_set_int(bld, params, key_saltlen, saltlen)))
 214             return 0;
 215     }
 216     return 1;
 217 }
 218
 219 int ossl_rsa_pss_params_30_fromdata(RSA_PSS_PARAMS_30 *pss_params,
 220                                     const OSSL_PARAM params[],
 221                                     OSSL_LIB_CTX *libctx)
 222 {
 223     const OSSL_PARAM *param_md, *param_mgf, *param_mgf1md,  *param_saltlen;
 224     const OSSL_PARAM *param_propq;
 225     const char *propq = NULL;
 226     EVP_MD *md = NULL, *mgf1md = NULL;
 227     int saltlen;
 228     int ret = 0;
 229
 230     if (pss_params == NULL)
 231         return 0;
 232     param_propq =
 233         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST_PROPS);
 234     param_md =
 235         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_DIGEST);
 236     param_mgf =
 237         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MASKGENFUNC);
 238     param_mgf1md =
 239         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_MGF1_DIGEST);
 240     param_saltlen =
 241         OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_PSS_SALTLEN);
 242
 243     if (param_propq != NULL) {
 244         if (param_propq->data_type == OSSL_PARAM_UTF8_STRING)
 245             propq = param_propq->data;
 246     }
 247     /*
 248      * If we get any of the parameters, we know we have at least some
 249      * restrictions, so we start by setting default values, and let each
 250      * parameter override their specific restriction data.
 251      */
 252     if (param_md != NULL || param_mgf != NULL || param_mgf1md != NULL
 253         || param_saltlen != NULL)
 254         if (!ossl_rsa_pss_params_30_set_defaults(pss_params))
 255             return 0;
 256
 257     if (param_mgf != NULL) {
 258         int default_maskgenalg_nid = ossl_rsa_pss_params_30_maskgenalg(NULL);
 259         const char *mgfname = NULL;
 260
 261         if (param_mgf->data_type == OSSL_PARAM_UTF8_STRING)
 262             mgfname = param_mgf->data;
 263         else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgfname))
 264             return 0;
 265
 266         /* TODO Revisit this if / when a new MGF algorithm appears */
 267         if (strcasecmp(param_mgf->data,
 268                        ossl_rsa_mgf_nid2name(default_maskgenalg_nid)) != 0)
 269             return 0;
 270     }
 271
 272     /*
 273      * We're only interested in the NIDs that correspond to the MDs, so the
 274      * exact propquery is unimportant in the EVP_MD_fetch() calls below.
 275      */
 276
 277     if (param_md != NULL) {
 278         const char *mdname = NULL;
 279
 280         if (param_md->data_type == OSSL_PARAM_UTF8_STRING)
 281             mdname = param_md->data;
 282         else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mdname))
 283             goto err;
 284
 285         if ((md = EVP_MD_fetch(libctx, mdname, propq)) == NULL
 286             || !ossl_rsa_pss_params_30_set_hashalg(pss_params,
 287                                                    ossl_rsa_oaeppss_md2nid(md)))
 288             goto err;
 289     }
 290
 291     if (param_mgf1md != NULL) {
 292         const char *mgf1mdname = NULL;
 293
 294         if (param_mgf1md->data_type == OSSL_PARAM_UTF8_STRING)
 295             mgf1mdname = param_mgf1md->data;
 296         else if (!OSSL_PARAM_get_utf8_ptr(param_mgf, &mgf1mdname))
 297             goto err;
 298
 299         if ((mgf1md = EVP_MD_fetch(libctx, mgf1mdname, propq)) == NULL
 300             || !ossl_rsa_pss_params_30_set_maskgenhashalg(
 301                     pss_params, ossl_rsa_oaeppss_md2nid(mgf1md)))
 302             goto err;
 303     }
 304
 305     if (param_saltlen != NULL) {
 306         if (!OSSL_PARAM_get_int(param_saltlen, &saltlen)
 307             || !ossl_rsa_pss_params_30_set_saltlen(pss_params, saltlen))
 308             goto err;
 309     }
 310
 311     ret = 1;
 312
 313  err:
 314     EVP_MD_free(md);
 315     EVP_MD_free(mgf1md);
 316     return ret;
 317 }