crypto/dsa/dsa_check.c

   1 /*
   2  * Copyright 1995-2019 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 <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/bn.h>
  13 #include "dsa_local.h"
  14 #include "crypto/dsa.h"
  15
  16 int dsa_check_params(const DSA *dsa, int *ret)
  17 {
  18     /*
  19      * (2b) FFC domain params conform to FIPS-186-4 explicit domain param
  20      * validity tests.
  21      */
  22     return ffc_params_FIPS186_4_validate(&dsa->params, FFC_PARAM_TYPE_DSA, NULL,
  23                                          FFC_PARAMS_VALIDATE_ALL, ret, NULL);
  24 }
  25
  26 /*
  27  * See SP800-56Ar3 Section 5.6.2.3.1 : FFC Full public key validation.
  28  */
  29 int dsa_check_pub_key(const DSA *dsa, const BIGNUM *pub_key, int *ret)
  30 {
  31     return ffc_validate_public_key(&dsa->params, pub_key, ret);
  32 }
  33
  34 /*
  35  * See SP800-56Ar3 Section 5.6.2.3.1 : FFC Partial public key validation.
  36  * To only be used with ephemeral FFC public keys generated using the approved
  37  * safe-prime groups.
  38  */
  39 int dsa_check_pub_key_partial(const DSA *dsa, const BIGNUM *pub_key, int *ret)
  40 {
  41     return ffc_validate_public_key_partial(&dsa->params, pub_key, ret);
  42 }
  43
  44 int dsa_check_priv_key(const DSA *dsa, const BIGNUM *priv_key, int *ret)
  45 {
  46     *ret = 0;
  47
  48     return (dsa->params.q != NULL
  49             && ffc_validate_private_key(dsa->params.q, priv_key, ret));
  50 }
  51
  52 /*
  53  * FFC pairwise check from SP800-56A R3.
  54  *    Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency
  55  */
  56 int dsa_check_pairwise(const DSA *dsa)
  57 {
  58     int ret = 0;
  59     BN_CTX *ctx = NULL;
  60     BIGNUM *pub_key = NULL;
  61
  62     if (dsa->params.p == NULL
  63         || dsa->params.g == NULL
  64         || dsa->priv_key == NULL
  65         || dsa->pub_key == NULL)
  66         return 0;
  67
  68     ctx = BN_CTX_new_ex(dsa->libctx);
  69     if (ctx == NULL)
  70         goto err;
  71     pub_key = BN_new();
  72     if (pub_key == NULL)
  73         goto err;
  74
  75     /* recalculate the public key = (g ^ priv) mod p */
  76     if (!dsa_generate_public_key(ctx, dsa, dsa->priv_key, pub_key))
  77         goto err;
  78     /* check it matches the existing pubic_key */
  79     ret = BN_cmp(pub_key, dsa->pub_key) == 0;
  80 err:
  81     BN_free(pub_key);
  82     BN_CTX_free(ctx);
  83     return ret;
  84 }