1 /* $OpenBSD: rsa_chk.c,v 1.13 2017/01/29 17:49:23 beck Exp $ */ 2 /* ==================================================================== 3 * Copyright (c) 1999 The OpenSSL Project. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in 14 * the documentation and/or other materials provided with the 15 * distribution. 16 * 17 * 3. All advertising materials mentioning features or use of this 18 * software must display the following acknowledgment: 19 * "This product includes software developed by the OpenSSL Project 20 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 21 * 22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 23 * endorse or promote products derived from this software without 24 * prior written permission. For written permission, please contact 25 * openssl-core@OpenSSL.org. 26 * 27 * 5. Products derived from this software may not be called "OpenSSL" 28 * nor may "OpenSSL" appear in their names without prior written 29 * permission of the OpenSSL Project. 30 * 31 * 6. Redistributions of any form whatsoever must retain the following 32 * acknowledgment: 33 * "This product includes software developed by the OpenSSL Project 34 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 35 * 36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 47 * OF THE POSSIBILITY OF SUCH DAMAGE. 48 * ==================================================================== 49 */ 50 51 #include <openssl/bn.h> 52 #include <openssl/err.h> 53 #include <openssl/rsa.h> 54 55 #include "bn_lcl.h" 56 57 int 58 RSA_check_key(const RSA *key) 59 { 60 BIGNUM *i, *j, *k, *l, *m; 61 BN_CTX *ctx; 62 int r; 63 int ret = 1; 64 65 if (!key->p || !key->q || !key->n || !key->e || !key->d) { 66 RSAerror(RSA_R_VALUE_MISSING); 67 return 0; 68 } 69 70 i = BN_new(); 71 j = BN_new(); 72 k = BN_new(); 73 l = BN_new(); 74 m = BN_new(); 75 ctx = BN_CTX_new(); 76 if (i == NULL || j == NULL || k == NULL || l == NULL || m == NULL || 77 ctx == NULL) { 78 ret = -1; 79 RSAerror(ERR_R_MALLOC_FAILURE); 80 goto err; 81 } 82 83 /* p prime? */ 84 r = BN_is_prime_ex(key->p, BN_prime_checks, NULL, NULL); 85 if (r != 1) { 86 ret = r; 87 if (r != 0) 88 goto err; 89 RSAerror(RSA_R_P_NOT_PRIME); 90 } 91 92 /* q prime? */ 93 r = BN_is_prime_ex(key->q, BN_prime_checks, NULL, NULL); 94 if (r != 1) { 95 ret = r; 96 if (r != 0) 97 goto err; 98 RSAerror(RSA_R_Q_NOT_PRIME); 99 } 100 101 /* n = p*q? */ 102 r = BN_mul(i, key->p, key->q, ctx); 103 if (!r) { 104 ret = -1; 105 goto err; 106 } 107 108 if (BN_cmp(i, key->n) != 0) { 109 ret = 0; 110 RSAerror(RSA_R_N_DOES_NOT_EQUAL_P_Q); 111 } 112 113 /* d*e = 1 mod lcm(p-1,q-1)? */ 114 115 r = BN_sub(i, key->p, BN_value_one()); 116 if (!r) { 117 ret = -1; 118 goto err; 119 } 120 r = BN_sub(j, key->q, BN_value_one()); 121 if (!r) { 122 ret = -1; 123 goto err; 124 } 125 126 /* now compute k = lcm(i,j) */ 127 r = BN_mul(l, i, j, ctx); 128 if (!r) { 129 ret = -1; 130 goto err; 131 } 132 r = BN_gcd_ct(m, i, j, ctx); 133 if (!r) { 134 ret = -1; 135 goto err; 136 } 137 r = BN_div_ct(k, NULL, l, m, ctx); /* remainder is 0 */ 138 if (!r) { 139 ret = -1; 140 goto err; 141 } 142 143 r = BN_mod_mul(i, key->d, key->e, k, ctx); 144 if (!r) { 145 ret = -1; 146 goto err; 147 } 148 149 if (!BN_is_one(i)) { 150 ret = 0; 151 RSAerror(RSA_R_D_E_NOT_CONGRUENT_TO_1); 152 } 153 154 if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL) { 155 /* dmp1 = d mod (p-1)? */ 156 r = BN_sub(i, key->p, BN_value_one()); 157 if (!r) { 158 ret = -1; 159 goto err; 160 } 161 162 r = BN_mod_ct(j, key->d, i, ctx); 163 if (!r) { 164 ret = -1; 165 goto err; 166 } 167 168 if (BN_cmp(j, key->dmp1) != 0) { 169 ret = 0; 170 RSAerror(RSA_R_DMP1_NOT_CONGRUENT_TO_D); 171 } 172 173 /* dmq1 = d mod (q-1)? */ 174 r = BN_sub(i, key->q, BN_value_one()); 175 if (!r) { 176 ret = -1; 177 goto err; 178 } 179 180 r = BN_mod_ct(j, key->d, i, ctx); 181 if (!r) { 182 ret = -1; 183 goto err; 184 } 185 186 if (BN_cmp(j, key->dmq1) != 0) { 187 ret = 0; 188 RSAerror(RSA_R_DMQ1_NOT_CONGRUENT_TO_D); 189 } 190 191 /* iqmp = q^-1 mod p? */ 192 if (!BN_mod_inverse_ct(i, key->q, key->p, ctx)) { 193 ret = -1; 194 goto err; 195 } 196 197 if (BN_cmp(i, key->iqmp) != 0) { 198 ret = 0; 199 RSAerror(RSA_R_IQMP_NOT_INVERSE_OF_Q); 200 } 201 } 202 203 err: 204 BN_free(i); 205 BN_free(j); 206 BN_free(k); 207 BN_free(l); 208 BN_free(m); 209 BN_CTX_free(ctx); 210 211 return (ret); 212 } 213