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 <openssl/core_names.h>
  11 #include <openssl/params.h>
  12 #include "crypto/rsa.h"
  13
  14 /*
  15  * The intention with the "backend" source file is to offer backend support
  16  * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
  17  * implementations alike.
  18  */
  19
  20 DEFINE_STACK_OF(BIGNUM)
  21
  22 static int collect_numbers(STACK_OF(BIGNUM) *numbers,
  23                            const OSSL_PARAM params[], const char *names[])
  24 {
  25     const OSSL_PARAM *p = NULL;
  26     int i;
  27
  28     if (numbers == NULL)
  29         return 0;
  30
  31     for (i = 0; names[i] != NULL; i++){
  32         p = OSSL_PARAM_locate_const(params, names[i]);
  33         if (p != NULL) {
  34             BIGNUM *tmp = NULL;
  35
  36             if (!OSSL_PARAM_get_BN(p, &tmp)
  37                 || sk_BIGNUM_push(numbers, tmp) == 0)
  38                 return 0;
  39         }
  40     }
  41
  42     return 1;
  43 }
  44
  45 int rsa_fromdata(RSA *rsa, const OSSL_PARAM params[])
  46 {
  47     const OSSL_PARAM *param_n, *param_e,  *param_d;
  48     BIGNUM *n = NULL, *e = NULL, *d = NULL;
  49     STACK_OF(BIGNUM) *factors = NULL, *exps = NULL, *coeffs = NULL;
  50     int is_private = 0;
  51
  52     if (rsa == NULL)
  53         return 0;
  54
  55     param_n = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_N);
  56     param_e = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_E);
  57     param_d = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_RSA_D);
  58
  59     if ((param_n != NULL && !OSSL_PARAM_get_BN(param_n, &n))
  60         || (param_e != NULL && !OSSL_PARAM_get_BN(param_e, &e))
  61         || (param_d != NULL && !OSSL_PARAM_get_BN(param_d, &d)))
  62         goto err;
  63
  64     is_private = (d != NULL);
  65
  66     if (!RSA_set0_key(rsa, n, e, d))
  67         goto err;
  68     n = e = d = NULL;
  69
  70     if (is_private) {
  71         if (!collect_numbers(factors = sk_BIGNUM_new_null(), params,
  72                              rsa_mp_factor_names)
  73             || !collect_numbers(exps = sk_BIGNUM_new_null(), params,
  74                                 rsa_mp_exp_names)
  75             || !collect_numbers(coeffs = sk_BIGNUM_new_null(), params,
  76                                 rsa_mp_coeff_names))
  77             goto err;
  78
  79         /* It's ok if this private key just has n, e and d */
  80         if (sk_BIGNUM_num(factors) != 0
  81             && !rsa_set0_all_params(rsa, factors, exps, coeffs))
  82             goto err;
  83     }
  84
  85     sk_BIGNUM_free(factors);
  86     sk_BIGNUM_free(exps);
  87     sk_BIGNUM_free(coeffs);
  88     return 1;
  89
  90  err:
  91     BN_free(n);
  92     BN_free(e);
  93     BN_free(d);
  94     sk_BIGNUM_pop_free(factors, BN_free);
  95     sk_BIGNUM_pop_free(exps, BN_free);
  96     sk_BIGNUM_pop_free(coeffs, BN_free);
  97     return 0;
  98 }
  99
 100 DEFINE_SPECIAL_STACK_OF_CONST(BIGNUM_const, BIGNUM)
 101
 102 int rsa_todata(RSA *rsa, OSSL_PARAM_BLD *bld, OSSL_PARAM params[])
 103 {
 104     int ret = 0;
 105     const BIGNUM *rsa_d = NULL, *rsa_n = NULL, *rsa_e = NULL;
 106     STACK_OF(BIGNUM_const) *factors = sk_BIGNUM_const_new_null();
 107     STACK_OF(BIGNUM_const) *exps = sk_BIGNUM_const_new_null();
 108     STACK_OF(BIGNUM_const) *coeffs = sk_BIGNUM_const_new_null();
 109
 110     if (rsa == NULL || factors == NULL || exps == NULL || coeffs == NULL)
 111         goto err;
 112
 113     RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
 114     rsa_get0_all_params(rsa, factors, exps, coeffs);
 115
 116     /* Check private key data integrity */
 117     if (rsa_d != NULL) {
 118         int numprimes = sk_BIGNUM_const_num(factors);
 119         int numexps = sk_BIGNUM_const_num(exps);
 120         int numcoeffs = sk_BIGNUM_const_num(coeffs);
 121
 122         /*
 123          * It's permisssible to have zero primes, i.e. no CRT params.
 124          * Otherwise, there must be at least two, as many exponents,
 125          * and one coefficient less.
 126          */
 127         if (numprimes != 0
 128             && (numprimes < 2 || numexps < 2 || numcoeffs < 1))
 129             goto err;
 130     }
 131
 132     if (!ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_N, rsa_n)
 133         || !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_E, rsa_e)
 134         || !ossl_param_build_set_bn(bld, params, OSSL_PKEY_PARAM_RSA_D, rsa_d)
 135         || !ossl_param_build_set_multi_key_bn(bld, params, rsa_mp_factor_names,
 136                                               factors)
 137         || !ossl_param_build_set_multi_key_bn(bld, params, rsa_mp_exp_names,
 138                                               exps)
 139         || !ossl_param_build_set_multi_key_bn(bld, params, rsa_mp_coeff_names,
 140                                               coeffs))
 141         goto err;
 142     ret = 1;
 143  err:
 144     sk_BIGNUM_const_free(factors);
 145     sk_BIGNUM_const_free(exps);
 146     sk_BIGNUM_const_free(coeffs);
 147     return ret;
 148 }