076fc55527
Document thread-safety issues Have RSA_null return NULL (always fails) Reviewed-by: Matt Caswell <matt@openssl.org> (Merged from https://github.com/openssl/openssl/pull/2244)
803 lines
23 KiB
C
803 lines
23 KiB
C
/*
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* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the OpenSSL license (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#include "internal/cryptlib.h"
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#include "internal/bn_int.h"
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#include "rsa_locl.h"
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static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding);
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static int rsa_ossl_private_encrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding);
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static int rsa_ossl_public_decrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding);
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static int rsa_ossl_private_decrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding);
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static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa,
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BN_CTX *ctx);
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static int rsa_ossl_init(RSA *rsa);
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static int rsa_ossl_finish(RSA *rsa);
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static RSA_METHOD rsa_pkcs1_ossl_meth = {
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"OpenSSL PKCS#1 RSA",
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rsa_ossl_public_encrypt,
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rsa_ossl_public_decrypt, /* signature verification */
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rsa_ossl_private_encrypt, /* signing */
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rsa_ossl_private_decrypt,
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rsa_ossl_mod_exp,
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BN_mod_exp_mont, /* XXX probably we should not use Montgomery
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* if e == 3 */
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rsa_ossl_init,
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rsa_ossl_finish,
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RSA_FLAG_FIPS_METHOD, /* flags */
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NULL,
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0, /* rsa_sign */
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0, /* rsa_verify */
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NULL /* rsa_keygen */
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};
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static const RSA_METHOD *default_RSA_meth = &rsa_pkcs1_ossl_meth;
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void RSA_set_default_method(const RSA_METHOD *meth)
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{
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default_RSA_meth = meth;
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}
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const RSA_METHOD *RSA_get_default_method(void)
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{
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return default_RSA_meth;
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}
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const RSA_METHOD *RSA_PKCS1_OpenSSL(void)
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{
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return &rsa_pkcs1_ossl_meth;
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}
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const RSA_METHOD *RSA_null_method(void)
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{
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return NULL;
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}
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static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding)
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{
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BIGNUM *f, *ret;
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int i, j, k, num = 0, r = -1;
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unsigned char *buf = NULL;
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BN_CTX *ctx = NULL;
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if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
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RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
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return -1;
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}
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if (BN_ucmp(rsa->n, rsa->e) <= 0) {
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RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
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return -1;
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}
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/* for large moduli, enforce exponent limit */
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if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
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if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
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RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
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return -1;
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}
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}
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if ((ctx = BN_CTX_new()) == NULL)
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goto err;
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BN_CTX_start(ctx);
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f = BN_CTX_get(ctx);
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ret = BN_CTX_get(ctx);
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num = BN_num_bytes(rsa->n);
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buf = OPENSSL_malloc(num);
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if (f == NULL || ret == NULL || buf == NULL) {
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RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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switch (padding) {
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case RSA_PKCS1_PADDING:
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i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
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break;
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case RSA_PKCS1_OAEP_PADDING:
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i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
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break;
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case RSA_SSLV23_PADDING:
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i = RSA_padding_add_SSLv23(buf, num, from, flen);
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break;
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case RSA_NO_PADDING:
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i = RSA_padding_add_none(buf, num, from, flen);
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break;
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default:
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RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
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goto err;
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}
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if (i <= 0)
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goto err;
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if (BN_bin2bn(buf, num, f) == NULL)
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goto err;
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if (BN_ucmp(f, rsa->n) >= 0) {
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/* usually the padding functions would catch this */
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RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT,
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RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
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goto err;
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}
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if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
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if (!BN_MONT_CTX_set_locked
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(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))
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goto err;
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if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
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rsa->_method_mod_n))
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goto err;
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/*
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* put in leading 0 bytes if the number is less than the length of the
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* modulus
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*/
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j = BN_num_bytes(ret);
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i = BN_bn2bin(ret, &(to[num - j]));
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for (k = 0; k < (num - i); k++)
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to[k] = 0;
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r = num;
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err:
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if (ctx != NULL)
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BN_CTX_end(ctx);
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BN_CTX_free(ctx);
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OPENSSL_clear_free(buf, num);
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return (r);
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}
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static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
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{
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BN_BLINDING *ret;
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CRYPTO_THREAD_write_lock(rsa->lock);
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if (rsa->blinding == NULL) {
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rsa->blinding = RSA_setup_blinding(rsa, ctx);
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}
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ret = rsa->blinding;
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if (ret == NULL)
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goto err;
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if (BN_BLINDING_is_current_thread(ret)) {
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/* rsa->blinding is ours! */
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*local = 1;
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} else {
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/* resort to rsa->mt_blinding instead */
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/*
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* instructs rsa_blinding_convert(), rsa_blinding_invert() that the
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* BN_BLINDING is shared, meaning that accesses require locks, and
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* that the blinding factor must be stored outside the BN_BLINDING
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*/
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*local = 0;
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if (rsa->mt_blinding == NULL) {
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rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
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}
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ret = rsa->mt_blinding;
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}
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err:
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CRYPTO_THREAD_unlock(rsa->lock);
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return ret;
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}
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static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
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BN_CTX *ctx)
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{
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if (unblind == NULL)
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/*
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* Local blinding: store the unblinding factor in BN_BLINDING.
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*/
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return BN_BLINDING_convert_ex(f, NULL, b, ctx);
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else {
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/*
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* Shared blinding: store the unblinding factor outside BN_BLINDING.
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*/
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int ret;
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BN_BLINDING_lock(b);
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ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
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BN_BLINDING_unlock(b);
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return ret;
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}
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}
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static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
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BN_CTX *ctx)
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{
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/*
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* For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
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* will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
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* is shared between threads, unblind must be non-null:
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* BN_BLINDING_invert_ex will then use the local unblinding factor, and
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* will only read the modulus from BN_BLINDING. In both cases it's safe
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* to access the blinding without a lock.
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*/
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return BN_BLINDING_invert_ex(f, unblind, b, ctx);
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}
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/* signing */
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static int rsa_ossl_private_encrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding)
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{
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BIGNUM *f, *ret, *res;
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int i, j, k, num = 0, r = -1;
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unsigned char *buf = NULL;
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BN_CTX *ctx = NULL;
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int local_blinding = 0;
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/*
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* Used only if the blinding structure is shared. A non-NULL unblind
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* instructs rsa_blinding_convert() and rsa_blinding_invert() to store
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* the unblinding factor outside the blinding structure.
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*/
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BIGNUM *unblind = NULL;
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BN_BLINDING *blinding = NULL;
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if ((ctx = BN_CTX_new()) == NULL)
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goto err;
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BN_CTX_start(ctx);
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f = BN_CTX_get(ctx);
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ret = BN_CTX_get(ctx);
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num = BN_num_bytes(rsa->n);
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buf = OPENSSL_malloc(num);
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if (f == NULL || ret == NULL || buf == NULL) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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switch (padding) {
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case RSA_PKCS1_PADDING:
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i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
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break;
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case RSA_X931_PADDING:
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i = RSA_padding_add_X931(buf, num, from, flen);
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break;
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case RSA_NO_PADDING:
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i = RSA_padding_add_none(buf, num, from, flen);
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break;
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case RSA_SSLV23_PADDING:
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default:
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
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goto err;
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}
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if (i <= 0)
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goto err;
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if (BN_bin2bn(buf, num, f) == NULL)
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goto err;
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if (BN_ucmp(f, rsa->n) >= 0) {
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/* usually the padding functions would catch this */
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT,
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RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
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goto err;
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}
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if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
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blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
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if (blinding == NULL) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
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goto err;
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}
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}
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if (blinding != NULL) {
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if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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if (!rsa_blinding_convert(blinding, f, unblind, ctx))
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goto err;
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}
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if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
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((rsa->p != NULL) &&
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(rsa->q != NULL) &&
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(rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
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if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
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goto err;
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} else {
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BIGNUM *d = BN_new();
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if (d == NULL) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
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if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
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if (!BN_MONT_CTX_set_locked
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(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) {
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BN_free(d);
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goto err;
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}
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if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
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rsa->_method_mod_n)) {
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BN_free(d);
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goto err;
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}
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/* We MUST free d before any further use of rsa->d */
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BN_free(d);
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}
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if (blinding)
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if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
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goto err;
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if (padding == RSA_X931_PADDING) {
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BN_sub(f, rsa->n, ret);
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if (BN_cmp(ret, f) > 0)
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res = f;
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else
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res = ret;
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} else
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res = ret;
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/*
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* put in leading 0 bytes if the number is less than the length of the
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* modulus
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*/
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j = BN_num_bytes(res);
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i = BN_bn2bin(res, &(to[num - j]));
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for (k = 0; k < (num - i); k++)
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to[k] = 0;
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r = num;
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err:
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if (ctx != NULL)
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BN_CTX_end(ctx);
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BN_CTX_free(ctx);
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OPENSSL_clear_free(buf, num);
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return (r);
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}
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static int rsa_ossl_private_decrypt(int flen, const unsigned char *from,
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unsigned char *to, RSA *rsa, int padding)
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{
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BIGNUM *f, *ret;
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int j, num = 0, r = -1;
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unsigned char *p;
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unsigned char *buf = NULL;
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BN_CTX *ctx = NULL;
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int local_blinding = 0;
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/*
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* Used only if the blinding structure is shared. A non-NULL unblind
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* instructs rsa_blinding_convert() and rsa_blinding_invert() to store
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* the unblinding factor outside the blinding structure.
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*/
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BIGNUM *unblind = NULL;
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BN_BLINDING *blinding = NULL;
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if ((ctx = BN_CTX_new()) == NULL)
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goto err;
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BN_CTX_start(ctx);
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f = BN_CTX_get(ctx);
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ret = BN_CTX_get(ctx);
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num = BN_num_bytes(rsa->n);
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buf = OPENSSL_malloc(num);
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if (f == NULL || ret == NULL || buf == NULL) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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/*
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* This check was for equality but PGP does evil things and chops off the
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* top '0' bytes
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*/
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if (flen > num) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT,
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RSA_R_DATA_GREATER_THAN_MOD_LEN);
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goto err;
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}
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/* make data into a big number */
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if (BN_bin2bn(from, (int)flen, f) == NULL)
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goto err;
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if (BN_ucmp(f, rsa->n) >= 0) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT,
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RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
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goto err;
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}
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if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
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blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
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if (blinding == NULL) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
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goto err;
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}
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}
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if (blinding != NULL) {
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if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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if (!rsa_blinding_convert(blinding, f, unblind, ctx))
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goto err;
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}
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/* do the decrypt */
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if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
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((rsa->p != NULL) &&
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(rsa->q != NULL) &&
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(rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
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if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
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goto err;
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} else {
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BIGNUM *d = BN_new();
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if (d == NULL) {
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RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
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goto err;
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}
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BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
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if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
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if (!BN_MONT_CTX_set_locked
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(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) {
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BN_free(d);
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goto err;
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}
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if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
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rsa->_method_mod_n)) {
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BN_free(d);
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goto err;
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}
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/* We MUST free d before any further use of rsa->d */
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BN_free(d);
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}
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if (blinding)
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if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
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goto err;
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p = buf;
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j = BN_bn2bin(ret, p); /* j is only used with no-padding mode */
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switch (padding) {
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case RSA_PKCS1_PADDING:
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r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num);
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break;
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case RSA_PKCS1_OAEP_PADDING:
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r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
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break;
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case RSA_SSLV23_PADDING:
|
|
r = RSA_padding_check_SSLv23(to, num, buf, j, num);
|
|
break;
|
|
case RSA_NO_PADDING:
|
|
r = RSA_padding_check_none(to, num, buf, j, num);
|
|
break;
|
|
default:
|
|
RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
|
|
goto err;
|
|
}
|
|
if (r < 0)
|
|
RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
|
|
|
|
err:
|
|
if (ctx != NULL)
|
|
BN_CTX_end(ctx);
|
|
BN_CTX_free(ctx);
|
|
OPENSSL_clear_free(buf, num);
|
|
return (r);
|
|
}
|
|
|
|
/* signature verification */
|
|
static int rsa_ossl_public_decrypt(int flen, const unsigned char *from,
|
|
unsigned char *to, RSA *rsa, int padding)
|
|
{
|
|
BIGNUM *f, *ret;
|
|
int i, num = 0, r = -1;
|
|
unsigned char *p;
|
|
unsigned char *buf = NULL;
|
|
BN_CTX *ctx = NULL;
|
|
|
|
if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
|
|
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
|
|
return -1;
|
|
}
|
|
|
|
if (BN_ucmp(rsa->n, rsa->e) <= 0) {
|
|
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
|
|
return -1;
|
|
}
|
|
|
|
/* for large moduli, enforce exponent limit */
|
|
if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
|
|
if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
|
|
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
if ((ctx = BN_CTX_new()) == NULL)
|
|
goto err;
|
|
BN_CTX_start(ctx);
|
|
f = BN_CTX_get(ctx);
|
|
ret = BN_CTX_get(ctx);
|
|
num = BN_num_bytes(rsa->n);
|
|
buf = OPENSSL_malloc(num);
|
|
if (f == NULL || ret == NULL || buf == NULL) {
|
|
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
|
|
goto err;
|
|
}
|
|
|
|
/*
|
|
* This check was for equality but PGP does evil things and chops off the
|
|
* top '0' bytes
|
|
*/
|
|
if (flen > num) {
|
|
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_DATA_GREATER_THAN_MOD_LEN);
|
|
goto err;
|
|
}
|
|
|
|
if (BN_bin2bn(from, flen, f) == NULL)
|
|
goto err;
|
|
|
|
if (BN_ucmp(f, rsa->n) >= 0) {
|
|
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT,
|
|
RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
|
|
goto err;
|
|
}
|
|
|
|
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
|
|
if (!BN_MONT_CTX_set_locked
|
|
(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))
|
|
goto err;
|
|
|
|
if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
|
|
rsa->_method_mod_n))
|
|
goto err;
|
|
|
|
if ((padding == RSA_X931_PADDING) && ((bn_get_words(ret)[0] & 0xf) != 12))
|
|
if (!BN_sub(ret, rsa->n, ret))
|
|
goto err;
|
|
|
|
p = buf;
|
|
i = BN_bn2bin(ret, p);
|
|
|
|
switch (padding) {
|
|
case RSA_PKCS1_PADDING:
|
|
r = RSA_padding_check_PKCS1_type_1(to, num, buf, i, num);
|
|
break;
|
|
case RSA_X931_PADDING:
|
|
r = RSA_padding_check_X931(to, num, buf, i, num);
|
|
break;
|
|
case RSA_NO_PADDING:
|
|
r = RSA_padding_check_none(to, num, buf, i, num);
|
|
break;
|
|
default:
|
|
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
|
|
goto err;
|
|
}
|
|
if (r < 0)
|
|
RSAerr(RSA_F_RSA_OSSL_PUBLIC_DECRYPT, RSA_R_PADDING_CHECK_FAILED);
|
|
|
|
err:
|
|
if (ctx != NULL)
|
|
BN_CTX_end(ctx);
|
|
BN_CTX_free(ctx);
|
|
OPENSSL_clear_free(buf, num);
|
|
return (r);
|
|
}
|
|
|
|
static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
|
|
{
|
|
BIGNUM *r1, *m1, *vrfy;
|
|
int ret = 0;
|
|
|
|
BN_CTX_start(ctx);
|
|
|
|
r1 = BN_CTX_get(ctx);
|
|
m1 = BN_CTX_get(ctx);
|
|
vrfy = BN_CTX_get(ctx);
|
|
|
|
{
|
|
BIGNUM *p = BN_new(), *q = BN_new();
|
|
|
|
/*
|
|
* Make sure BN_mod_inverse in Montgomery initialization uses the
|
|
* BN_FLG_CONSTTIME flag
|
|
*/
|
|
if (p == NULL || q == NULL) {
|
|
BN_free(p);
|
|
BN_free(q);
|
|
goto err;
|
|
}
|
|
BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
|
|
BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
|
|
|
|
if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
|
|
if (!BN_MONT_CTX_set_locked
|
|
(&rsa->_method_mod_p, rsa->lock, p, ctx)
|
|
|| !BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
|
|
rsa->lock, q, ctx)) {
|
|
BN_free(p);
|
|
BN_free(q);
|
|
goto err;
|
|
}
|
|
}
|
|
/*
|
|
* We MUST free p and q before any further use of rsa->p and rsa->q
|
|
*/
|
|
BN_free(p);
|
|
BN_free(q);
|
|
}
|
|
|
|
if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
|
|
if (!BN_MONT_CTX_set_locked
|
|
(&rsa->_method_mod_n, rsa->lock, rsa->n, ctx))
|
|
goto err;
|
|
|
|
/* compute I mod q */
|
|
{
|
|
BIGNUM *c = BN_new();
|
|
if (c == NULL)
|
|
goto err;
|
|
BN_with_flags(c, I, BN_FLG_CONSTTIME);
|
|
|
|
if (!BN_mod(r1, c, rsa->q, ctx)) {
|
|
BN_free(c);
|
|
goto err;
|
|
}
|
|
|
|
{
|
|
BIGNUM *dmq1 = BN_new();
|
|
if (dmq1 == NULL) {
|
|
BN_free(c);
|
|
goto err;
|
|
}
|
|
BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
|
|
|
|
/* compute r1^dmq1 mod q */
|
|
if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx,
|
|
rsa->_method_mod_q)) {
|
|
BN_free(c);
|
|
BN_free(dmq1);
|
|
goto err;
|
|
}
|
|
/* We MUST free dmq1 before any further use of rsa->dmq1 */
|
|
BN_free(dmq1);
|
|
}
|
|
|
|
/* compute I mod p */
|
|
if (!BN_mod(r1, c, rsa->p, ctx)) {
|
|
BN_free(c);
|
|
goto err;
|
|
}
|
|
/* We MUST free c before any further use of I */
|
|
BN_free(c);
|
|
}
|
|
|
|
{
|
|
BIGNUM *dmp1 = BN_new();
|
|
if (dmp1 == NULL)
|
|
goto err;
|
|
BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
|
|
|
|
/* compute r1^dmp1 mod p */
|
|
if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx,
|
|
rsa->_method_mod_p)) {
|
|
BN_free(dmp1);
|
|
goto err;
|
|
}
|
|
/* We MUST free dmp1 before any further use of rsa->dmp1 */
|
|
BN_free(dmp1);
|
|
}
|
|
|
|
if (!BN_sub(r0, r0, m1))
|
|
goto err;
|
|
/*
|
|
* This will help stop the size of r0 increasing, which does affect the
|
|
* multiply if it optimised for a power of 2 size
|
|
*/
|
|
if (BN_is_negative(r0))
|
|
if (!BN_add(r0, r0, rsa->p))
|
|
goto err;
|
|
|
|
if (!BN_mul(r1, r0, rsa->iqmp, ctx))
|
|
goto err;
|
|
|
|
{
|
|
BIGNUM *pr1 = BN_new();
|
|
if (pr1 == NULL)
|
|
goto err;
|
|
BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
|
|
|
|
if (!BN_mod(r0, pr1, rsa->p, ctx)) {
|
|
BN_free(pr1);
|
|
goto err;
|
|
}
|
|
/* We MUST free pr1 before any further use of r1 */
|
|
BN_free(pr1);
|
|
}
|
|
|
|
/*
|
|
* If p < q it is occasionally possible for the correction of adding 'p'
|
|
* if r0 is negative above to leave the result still negative. This can
|
|
* break the private key operations: the following second correction
|
|
* should *always* correct this rare occurrence. This will *never* happen
|
|
* with OpenSSL generated keys because they ensure p > q [steve]
|
|
*/
|
|
if (BN_is_negative(r0))
|
|
if (!BN_add(r0, r0, rsa->p))
|
|
goto err;
|
|
if (!BN_mul(r1, r0, rsa->q, ctx))
|
|
goto err;
|
|
if (!BN_add(r0, r1, m1))
|
|
goto err;
|
|
|
|
if (rsa->e && rsa->n) {
|
|
if (!rsa->meth->bn_mod_exp(vrfy, r0, rsa->e, rsa->n, ctx,
|
|
rsa->_method_mod_n))
|
|
goto err;
|
|
/*
|
|
* If 'I' was greater than (or equal to) rsa->n, the operation will
|
|
* be equivalent to using 'I mod n'. However, the result of the
|
|
* verify will *always* be less than 'n' so we don't check for
|
|
* absolute equality, just congruency.
|
|
*/
|
|
if (!BN_sub(vrfy, vrfy, I))
|
|
goto err;
|
|
if (!BN_mod(vrfy, vrfy, rsa->n, ctx))
|
|
goto err;
|
|
if (BN_is_negative(vrfy))
|
|
if (!BN_add(vrfy, vrfy, rsa->n))
|
|
goto err;
|
|
if (!BN_is_zero(vrfy)) {
|
|
/*
|
|
* 'I' and 'vrfy' aren't congruent mod n. Don't leak
|
|
* miscalculated CRT output, just do a raw (slower) mod_exp and
|
|
* return that instead.
|
|
*/
|
|
|
|
BIGNUM *d = BN_new();
|
|
if (d == NULL)
|
|
goto err;
|
|
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
|
|
|
|
if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
|
|
rsa->_method_mod_n)) {
|
|
BN_free(d);
|
|
goto err;
|
|
}
|
|
/* We MUST free d before any further use of rsa->d */
|
|
BN_free(d);
|
|
}
|
|
}
|
|
ret = 1;
|
|
err:
|
|
BN_CTX_end(ctx);
|
|
return (ret);
|
|
}
|
|
|
|
static int rsa_ossl_init(RSA *rsa)
|
|
{
|
|
rsa->flags |= RSA_FLAG_CACHE_PUBLIC | RSA_FLAG_CACHE_PRIVATE;
|
|
return (1);
|
|
}
|
|
|
|
static int rsa_ossl_finish(RSA *rsa)
|
|
{
|
|
BN_MONT_CTX_free(rsa->_method_mod_n);
|
|
BN_MONT_CTX_free(rsa->_method_mod_p);
|
|
BN_MONT_CTX_free(rsa->_method_mod_q);
|
|
return (1);
|
|
}
|