1 /* 2 * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (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 <openssl/crypto.h> 12 #include "internal/cryptlib.h" 13 #include "internal/bn_int.h" 14 #include <openssl/rand.h> 15 #include "rsa_locl.h" 16 17 int RSA_bits(const RSA *r) 18 { 19 return BN_num_bits(r->n); 20 } 21 22 int RSA_size(const RSA *r) 23 { 24 return BN_num_bytes(r->n); 25 } 26 27 int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to, 28 RSA *rsa, int padding) 29 { 30 return rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding); 31 } 32 33 int RSA_private_encrypt(int flen, const unsigned char *from, 34 unsigned char *to, RSA *rsa, int padding) 35 { 36 return rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding); 37 } 38 39 int RSA_private_decrypt(int flen, const unsigned char *from, 40 unsigned char *to, RSA *rsa, int padding) 41 { 42 return rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding); 43 } 44 45 int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to, 46 RSA *rsa, int padding) 47 { 48 return rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding); 49 } 50 51 int RSA_flags(const RSA *r) 52 { 53 return r == NULL ? 0 : r->meth->flags; 54 } 55 56 void RSA_blinding_off(RSA *rsa) 57 { 58 BN_BLINDING_free(rsa->blinding); 59 rsa->blinding = NULL; 60 rsa->flags &= ~RSA_FLAG_BLINDING; 61 rsa->flags |= RSA_FLAG_NO_BLINDING; 62 } 63 64 int RSA_blinding_on(RSA *rsa, BN_CTX *ctx) 65 { 66 int ret = 0; 67 68 if (rsa->blinding != NULL) 69 RSA_blinding_off(rsa); 70 71 rsa->blinding = RSA_setup_blinding(rsa, ctx); 72 if (rsa->blinding == NULL) 73 goto err; 74 75 rsa->flags |= RSA_FLAG_BLINDING; 76 rsa->flags &= ~RSA_FLAG_NO_BLINDING; 77 ret = 1; 78 err: 79 return ret; 80 } 81 82 static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p, 83 const BIGNUM *q, BN_CTX *ctx) 84 { 85 BIGNUM *ret = NULL, *r0, *r1, *r2; 86 87 if (d == NULL || p == NULL || q == NULL) 88 return NULL; 89 90 BN_CTX_start(ctx); 91 r0 = BN_CTX_get(ctx); 92 r1 = BN_CTX_get(ctx); 93 r2 = BN_CTX_get(ctx); 94 if (r2 == NULL) 95 goto err; 96 97 if (!BN_sub(r1, p, BN_value_one())) 98 goto err; 99 if (!BN_sub(r2, q, BN_value_one())) 100 goto err; 101 if (!BN_mul(r0, r1, r2, ctx)) 102 goto err; 103 104 ret = BN_mod_inverse(NULL, d, r0, ctx); 105 err: 106 BN_CTX_end(ctx); 107 return ret; 108 } 109 110 BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx) 111 { 112 BIGNUM *e; 113 BN_CTX *ctx; 114 BN_BLINDING *ret = NULL; 115 116 if (in_ctx == NULL) { 117 if ((ctx = BN_CTX_new()) == NULL) 118 return 0; 119 } else { 120 ctx = in_ctx; 121 } 122 123 BN_CTX_start(ctx); 124 e = BN_CTX_get(ctx); 125 if (e == NULL) { 126 RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE); 127 goto err; 128 } 129 130 if (rsa->e == NULL) { 131 e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx); 132 if (e == NULL) { 133 RSAerr(RSA_F_RSA_SETUP_BLINDING, RSA_R_NO_PUBLIC_EXPONENT); 134 goto err; 135 } 136 } else { 137 e = rsa->e; 138 } 139 140 { 141 BIGNUM *n = BN_new(); 142 143 if (n == NULL) { 144 RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE); 145 goto err; 146 } 147 BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME); 148 149 ret = BN_BLINDING_create_param(NULL, e, n, ctx, rsa->meth->bn_mod_exp, 150 rsa->_method_mod_n); 151 /* We MUST free n before any further use of rsa->n */ 152 BN_free(n); 153 } 154 if (ret == NULL) { 155 RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB); 156 goto err; 157 } 158 159 BN_BLINDING_set_current_thread(ret); 160 161 err: 162 BN_CTX_end(ctx); 163 if (ctx != in_ctx) 164 BN_CTX_free(ctx); 165 if (e != rsa->e) 166 BN_free(e); 167 168 return ret; 169 } 170