openssl/crypto/rsa/rsa_crpt.c

170 lines
3.9 KiB
C

/*
* Copyright 1995-2017 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 <stdio.h>
#include <openssl/crypto.h>
#include "internal/cryptlib.h"
#include "crypto/bn.h"
#include <openssl/rand.h>
#include "rsa_local.h"
int RSA_bits(const RSA *r)
{
return BN_num_bits(r->n);
}
int RSA_size(const RSA *r)
{
return BN_num_bytes(r->n);
}
int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
RSA *rsa, int padding)
{
return rsa->meth->rsa_pub_enc(flen, from, to, rsa, padding);
}
int RSA_private_encrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding)
{
return rsa->meth->rsa_priv_enc(flen, from, to, rsa, padding);
}
int RSA_private_decrypt(int flen, const unsigned char *from,
unsigned char *to, RSA *rsa, int padding)
{
return rsa->meth->rsa_priv_dec(flen, from, to, rsa, padding);
}
int RSA_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
RSA *rsa, int padding)
{
return rsa->meth->rsa_pub_dec(flen, from, to, rsa, padding);
}
int RSA_flags(const RSA *r)
{
return r == NULL ? 0 : r->meth->flags;
}
void RSA_blinding_off(RSA *rsa)
{
BN_BLINDING_free(rsa->blinding);
rsa->blinding = NULL;
rsa->flags &= ~RSA_FLAG_BLINDING;
rsa->flags |= RSA_FLAG_NO_BLINDING;
}
int RSA_blinding_on(RSA *rsa, BN_CTX *ctx)
{
int ret = 0;
if (rsa->blinding != NULL)
RSA_blinding_off(rsa);
rsa->blinding = RSA_setup_blinding(rsa, ctx);
if (rsa->blinding == NULL)
goto err;
rsa->flags |= RSA_FLAG_BLINDING;
rsa->flags &= ~RSA_FLAG_NO_BLINDING;
ret = 1;
err:
return ret;
}
static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,
const BIGNUM *q, BN_CTX *ctx)
{
BIGNUM *ret = NULL, *r0, *r1, *r2;
if (d == NULL || p == NULL || q == NULL)
return NULL;
BN_CTX_start(ctx);
r0 = BN_CTX_get(ctx);
r1 = BN_CTX_get(ctx);
r2 = BN_CTX_get(ctx);
if (r2 == NULL)
goto err;
if (!BN_sub(r1, p, BN_value_one()))
goto err;
if (!BN_sub(r2, q, BN_value_one()))
goto err;
if (!BN_mul(r0, r1, r2, ctx))
goto err;
ret = BN_mod_inverse(NULL, d, r0, ctx);
err:
BN_CTX_end(ctx);
return ret;
}
BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
{
BIGNUM *e;
BN_CTX *ctx;
BN_BLINDING *ret = NULL;
if (in_ctx == NULL) {
if ((ctx = BN_CTX_new()) == NULL)
return 0;
} else {
ctx = in_ctx;
}
BN_CTX_start(ctx);
e = BN_CTX_get(ctx);
if (e == NULL) {
RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);
goto err;
}
if (rsa->e == NULL) {
e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
if (e == NULL) {
RSAerr(RSA_F_RSA_SETUP_BLINDING, RSA_R_NO_PUBLIC_EXPONENT);
goto err;
}
} else {
e = rsa->e;
}
{
BIGNUM *n = BN_new();
if (n == NULL) {
RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);
goto err;
}
BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);
ret = BN_BLINDING_create_param(NULL, e, n, ctx, rsa->meth->bn_mod_exp,
rsa->_method_mod_n);
/* We MUST free n before any further use of rsa->n */
BN_free(n);
}
if (ret == NULL) {
RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB);
goto err;
}
BN_BLINDING_set_current_thread(ret);
err:
BN_CTX_end(ctx);
if (ctx != in_ctx)
BN_CTX_free(ctx);
if (e != rsa->e)
BN_free(e);
return ret;
}