text: /*
   * Copyright 1999-2017 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include <openssl/bn.h>
  #include <openssl/err.h>
  #include "rsa_locl.h"
  
  int RSA_check_key(const RSA *key)
  {
      return RSA_check_key_ex(key, NULL);
  }
  
  int RSA_check_key_ex(const RSA *key, BN_GENCB *cb)
  {
      BIGNUM *i, *j, *k, *l, *m;
      BN_CTX *ctx;
      int ret = 1, ex_primes = 0, idx;
      RSA_PRIME_INFO *pinfo;
  
      if (key->p == NULL || key->q == NULL || key->n == NULL
              || key->e == NULL || key->d == NULL) {
          RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_VALUE_MISSING);
          return 0;
      }
  
      /* multi-prime? */
      if (key->version == RSA_ASN1_VERSION_MULTI) {
          ex_primes = sk_RSA_PRIME_INFO_num(key->prime_infos);
          if (ex_primes <= 0
                  || (ex_primes + 2) > rsa_multip_cap(BN_num_bits(key->n))) {
              RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_INVALID_MULTI_PRIME_KEY);
              return 0;
          }
      }
  
      i = BN_new();
      j = BN_new();
      k = BN_new();
      l = BN_new();
      m = BN_new();
      ctx = BN_CTX_new();
      if (i == NULL || j == NULL || k == NULL || l == NULL
              || m == NULL || ctx == NULL) {
          ret = -1;
          RSAerr(RSA_F_RSA_CHECK_KEY_EX, ERR_R_MALLOC_FAILURE);
          goto err;
      }
  
      if (BN_is_one(key->e)) {
          ret = 0;
          RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_BAD_E_VALUE);
      }
      if (!BN_is_odd(key->e)) {
          ret = 0;
          RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_BAD_E_VALUE);
      }
  
      /* p prime? */
      if (BN_is_prime_ex(key->p, BN_prime_checks, NULL, cb) != 1) {
          ret = 0;
          RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_P_NOT_PRIME);
      }
  
      /* q prime? */
      if (BN_is_prime_ex(key->q, BN_prime_checks, NULL, cb) != 1) {
          ret = 0;
          RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_Q_NOT_PRIME);
      }
  
      /* r_i prime? */
      for (idx = 0; idx < ex_primes; idx++) {
          pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);
          if (BN_is_prime_ex(pinfo->r, BN_prime_checks, NULL, cb) != 1) {
              ret = 0;
              RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_MP_R_NOT_PRIME);
          }
      }
  
      /* n = p*q * r_3...r_i? */
      if (!BN_mul(i, key->p, key->q, ctx)) {
          ret = -1;
          goto err;
      }
      for (idx = 0; idx < ex_primes; idx++) {
          pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);
          if (!BN_mul(i, i, pinfo->r, ctx)) {
              ret = -1;
              goto err;
          }
      }
      if (BN_cmp(i, key->n) != 0) {
          ret = 0;
          if (ex_primes)
              RSAerr(RSA_F_RSA_CHECK_KEY_EX,
                     RSA_R_N_DOES_NOT_EQUAL_PRODUCT_OF_PRIMES);
          else
              RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_N_DOES_NOT_EQUAL_P_Q);
      }
  
      /* d*e = 1  mod \lambda(n)? */
      if (!BN_sub(i, key->p, BN_value_one())) {
          ret = -1;
          goto err;
      }
      if (!BN_sub(j, key->q, BN_value_one())) {
          ret = -1;
          goto err;
      }
  
      /* now compute k = \lambda(n) = LCM(i, j, r_3 - 1...) */
      if (!BN_mul(l, i, j, ctx)) {
          ret = -1;
          goto err;
      }
      if (!BN_gcd(m, i, j, ctx)) {
          ret = -1;
          goto err;
      }
      for (idx = 0; idx < ex_primes; idx++) {
          pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);
          if (!BN_sub(k, pinfo->r, BN_value_one())) {
              ret = -1;
              goto err;
          }
          if (!BN_mul(l, l, k, ctx)) {
              ret = -1;
              goto err;
          }
          if (!BN_gcd(m, m, k, ctx)) {
              ret = -1;
              goto err;
          }
      }
      if (!BN_div(k, NULL, l, m, ctx)) { /* remainder is 0 */
          ret = -1;
          goto err;
      }
      if (!BN_mod_mul(i, key->d, key->e, k, ctx)) {
          ret = -1;
          goto err;
      }
  
      if (!BN_is_one(i)) {
          ret = 0;
          RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_D_E_NOT_CONGRUENT_TO_1);
      }
  
      if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL) {
          /* dmp1 = d mod (p-1)? */
          if (!BN_sub(i, key->p, BN_value_one())) {
              ret = -1;
              goto err;
          }
          if (!BN_mod(j, key->d, i, ctx)) {
              ret = -1;
              goto err;
          }
          if (BN_cmp(j, key->dmp1) != 0) {
              ret = 0;
              RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_DMP1_NOT_CONGRUENT_TO_D);
          }
  
          /* dmq1 = d mod (q-1)? */
          if (!BN_sub(i, key->q, BN_value_one())) {
              ret = -1;
              goto err;
          }
          if (!BN_mod(j, key->d, i, ctx)) {
              ret = -1;
              goto err;
          }
          if (BN_cmp(j, key->dmq1) != 0) {
              ret = 0;
              RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_DMQ1_NOT_CONGRUENT_TO_D);
          }
  
          /* iqmp = q^-1 mod p? */
          if (!BN_mod_inverse(i, key->q, key->p, ctx)) {
              ret = -1;
              goto err;
          }
          if (BN_cmp(i, key->iqmp) != 0) {
              ret = 0;
              RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_IQMP_NOT_INVERSE_OF_Q);
          }
      }
  
      for (idx = 0; idx < ex_primes; idx++) {
          pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);
          /* d_i = d mod (r_i - 1)? */
          if (!BN_sub(i, pinfo->r, BN_value_one())) {
              ret = -1;
              goto err;
          }
          if (!BN_mod(j, key->d, i, ctx)) {
              ret = -1;
              goto err;
          }
          if (BN_cmp(j, pinfo->d) != 0) {
              ret = 0;
              RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_MP_EXPONENT_NOT_CONGRUENT_TO_D);
          }
          /* t_i = R_i ^ -1 mod r_i ? */
          if (!BN_mod_inverse(i, pinfo->pp, pinfo->r, ctx)) {
              ret = -1;
              goto err;
          }
          if (BN_cmp(i, pinfo->t) != 0) {
              ret = 0;
              RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_MP_COEFFICIENT_NOT_INVERSE_OF_R);
          }
      }
  
   err:
      BN_free(i);
      BN_free(j);
      BN_free(k);
      BN_free(l);
      BN_free(m);
      BN_CTX_free(ctx);
      return ret;
  }
  