--- /dev/null
+/*
+ * Copyright 1995-2016 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 "internal/cryptlib.h"
+#include "internal/bn_int.h"
+#include "rsa_locl.h"
+
+#ifndef RSA_NULL
+
+static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
+ unsigned char *to, RSA *rsa, int padding);
+static int rsa_ossl_private_encrypt(int flen, const unsigned char *from,
+ unsigned char *to, RSA *rsa, int padding);
+static int rsa_ossl_public_decrypt(int flen, const unsigned char *from,
+ unsigned char *to, RSA *rsa, int padding);
+static int rsa_ossl_private_decrypt(int flen, const unsigned char *from,
+ unsigned char *to, RSA *rsa, int padding);
+static int rsa_ossl_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa,
+ BN_CTX *ctx);
+static int rsa_ossl_init(RSA *rsa);
+static int rsa_ossl_finish(RSA *rsa);
+static RSA_METHOD rsa_pkcs1_ossl_meth = {
+ "OpenSSL PKCS#1 RSA (from Eric Young)",
+ rsa_ossl_public_encrypt,
+ rsa_ossl_public_decrypt, /* signature verification */
+ rsa_ossl_private_encrypt, /* signing */
+ rsa_ossl_private_decrypt,
+ rsa_ossl_mod_exp,
+ BN_mod_exp_mont, /* XXX probably we should not use Montgomery
+ * if e == 3 */
+ rsa_ossl_init,
+ rsa_ossl_finish,
+ RSA_FLAG_FIPS_METHOD, /* flags */
+ NULL,
+ 0, /* rsa_sign */
+ 0, /* rsa_verify */
+ NULL /* rsa_keygen */
+};
+
+const RSA_METHOD *RSA_PKCS1_OpenSSL(void)
+{
+ return &rsa_pkcs1_ossl_meth;
+}
+
+static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
+ unsigned char *to, RSA *rsa, int padding)
+{
+ BIGNUM *f, *ret;
+ int i, j, k, num = 0, r = -1;
+ 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_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
+ return -1;
+ }
+
+ if (BN_ucmp(rsa->n, rsa->e) <= 0) {
+ RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, 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_ENCRYPT, 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_ENCRYPT, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ switch (padding) {
+ case RSA_PKCS1_PADDING:
+ i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
+ break;
+ case RSA_PKCS1_OAEP_PADDING:
+ i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
+ break;
+ case RSA_SSLV23_PADDING:
+ i = RSA_padding_add_SSLv23(buf, num, from, flen);
+ break;
+ case RSA_NO_PADDING:
+ i = RSA_padding_add_none(buf, num, from, flen);
+ break;
+ default:
+ RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
+ goto err;
+ }
+ if (i <= 0)
+ goto err;
+
+ if (BN_bin2bn(buf, num, f) == NULL)
+ goto err;
+
+ if (BN_ucmp(f, rsa->n) >= 0) {
+ /* usually the padding functions would catch this */
+ RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT,
+ 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;
+
+ /*
+ * put in leading 0 bytes if the number is less than the length of the
+ * modulus
+ */
+ j = BN_num_bytes(ret);
+ i = BN_bn2bin(ret, &(to[num - j]));
+ for (k = 0; k < (num - i); k++)
+ to[k] = 0;
+
+ r = num;
+ err:
+ if (ctx != NULL)
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ OPENSSL_clear_free(buf, num);
+ return (r);
+}
+
+static BN_BLINDING *rsa_get_blinding(RSA *rsa, int *local, BN_CTX *ctx)
+{
+ BN_BLINDING *ret;
+
+ CRYPTO_THREAD_write_lock(rsa->lock);
+
+ if (rsa->blinding == NULL) {
+ rsa->blinding = RSA_setup_blinding(rsa, ctx);
+ }
+
+ ret = rsa->blinding;
+ if (ret == NULL)
+ goto err;
+
+ if (BN_BLINDING_is_current_thread(ret)) {
+ /* rsa->blinding is ours! */
+
+ *local = 1;
+ } else {
+ /* resort to rsa->mt_blinding instead */
+
+ /*
+ * instructs rsa_blinding_convert(), rsa_blinding_invert() that the
+ * BN_BLINDING is shared, meaning that accesses require locks, and
+ * that the blinding factor must be stored outside the BN_BLINDING
+ */
+ *local = 0;
+
+ if (rsa->mt_blinding == NULL) {
+ rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
+ }
+ ret = rsa->mt_blinding;
+ }
+
+ err:
+ CRYPTO_THREAD_unlock(rsa->lock);
+ return ret;
+}
+
+static int rsa_blinding_convert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
+ BN_CTX *ctx)
+{
+ if (unblind == NULL)
+ /*
+ * Local blinding: store the unblinding factor in BN_BLINDING.
+ */
+ return BN_BLINDING_convert_ex(f, NULL, b, ctx);
+ else {
+ /*
+ * Shared blinding: store the unblinding factor outside BN_BLINDING.
+ */
+ int ret;
+
+ BN_BLINDING_lock(b);
+ ret = BN_BLINDING_convert_ex(f, unblind, b, ctx);
+ BN_BLINDING_unlock(b);
+
+ return ret;
+ }
+}
+
+static int rsa_blinding_invert(BN_BLINDING *b, BIGNUM *f, BIGNUM *unblind,
+ BN_CTX *ctx)
+{
+ /*
+ * For local blinding, unblind is set to NULL, and BN_BLINDING_invert_ex
+ * will use the unblinding factor stored in BN_BLINDING. If BN_BLINDING
+ * is shared between threads, unblind must be non-null:
+ * BN_BLINDING_invert_ex will then use the local unblinding factor, and
+ * will only read the modulus from BN_BLINDING. In both cases it's safe
+ * to access the blinding without a lock.
+ */
+ return BN_BLINDING_invert_ex(f, unblind, b, ctx);
+}
+
+/* signing */
+static int rsa_ossl_private_encrypt(int flen, const unsigned char *from,
+ unsigned char *to, RSA *rsa, int padding)
+{
+ BIGNUM *f, *ret, *res;
+ int i, j, k, num = 0, r = -1;
+ unsigned char *buf = NULL;
+ BN_CTX *ctx = NULL;
+ int local_blinding = 0;
+ /*
+ * Used only if the blinding structure is shared. A non-NULL unblind
+ * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
+ * the unblinding factor outside the blinding structure.
+ */
+ BIGNUM *unblind = NULL;
+ BN_BLINDING *blinding = NULL;
+
+ 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_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ switch (padding) {
+ case RSA_PKCS1_PADDING:
+ i = RSA_padding_add_PKCS1_type_1(buf, num, from, flen);
+ break;
+ case RSA_X931_PADDING:
+ i = RSA_padding_add_X931(buf, num, from, flen);
+ break;
+ case RSA_NO_PADDING:
+ i = RSA_padding_add_none(buf, num, from, flen);
+ break;
+ case RSA_SSLV23_PADDING:
+ default:
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
+ goto err;
+ }
+ if (i <= 0)
+ goto err;
+
+ if (BN_bin2bn(buf, num, f) == NULL)
+ goto err;
+
+ if (BN_ucmp(f, rsa->n) >= 0) {
+ /* usually the padding functions would catch this */
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT,
+ RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
+ goto err;
+ }
+
+ if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
+ blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
+ if (blinding == NULL) {
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ }
+
+ if (blinding != NULL) {
+ if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ if (!rsa_blinding_convert(blinding, f, unblind, ctx))
+ goto err;
+ }
+
+ if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
+ ((rsa->p != NULL) &&
+ (rsa->q != NULL) &&
+ (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
+ if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
+ goto err;
+ } else {
+ BIGNUM *d = BN_new();
+ if (d == NULL) {
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
+
+ if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
+ if (!BN_MONT_CTX_set_locked
+ (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) {
+ BN_free(d);
+ goto err;
+ }
+
+ if (!rsa->meth->bn_mod_exp(ret, f, 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);
+ }
+
+ if (blinding)
+ if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
+ goto err;
+
+ if (padding == RSA_X931_PADDING) {
+ BN_sub(f, rsa->n, ret);
+ if (BN_cmp(ret, f) > 0)
+ res = f;
+ else
+ res = ret;
+ } else
+ res = ret;
+
+ /*
+ * put in leading 0 bytes if the number is less than the length of the
+ * modulus
+ */
+ j = BN_num_bytes(res);
+ i = BN_bn2bin(res, &(to[num - j]));
+ for (k = 0; k < (num - i); k++)
+ to[k] = 0;
+
+ r = num;
+ err:
+ if (ctx != NULL)
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ OPENSSL_clear_free(buf, num);
+ return (r);
+}
+
+static int rsa_ossl_private_decrypt(int flen, const unsigned char *from,
+ unsigned char *to, RSA *rsa, int padding)
+{
+ BIGNUM *f, *ret;
+ int j, num = 0, r = -1;
+ unsigned char *p;
+ unsigned char *buf = NULL;
+ BN_CTX *ctx = NULL;
+ int local_blinding = 0;
+ /*
+ * Used only if the blinding structure is shared. A non-NULL unblind
+ * instructs rsa_blinding_convert() and rsa_blinding_invert() to store
+ * the unblinding factor outside the blinding structure.
+ */
+ BIGNUM *unblind = NULL;
+ BN_BLINDING *blinding = NULL;
+
+ 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_PRIVATE_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_PRIVATE_DECRYPT,
+ RSA_R_DATA_GREATER_THAN_MOD_LEN);
+ goto err;
+ }
+
+ /* make data into a big number */
+ if (BN_bin2bn(from, (int)flen, f) == NULL)
+ goto err;
+
+ if (BN_ucmp(f, rsa->n) >= 0) {
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT,
+ RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
+ goto err;
+ }
+
+ if (!(rsa->flags & RSA_FLAG_NO_BLINDING)) {
+ blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
+ if (blinding == NULL) {
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ }
+
+ if (blinding != NULL) {
+ if (!local_blinding && ((unblind = BN_CTX_get(ctx)) == NULL)) {
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ if (!rsa_blinding_convert(blinding, f, unblind, ctx))
+ goto err;
+ }
+
+ /* do the decrypt */
+ if ((rsa->flags & RSA_FLAG_EXT_PKEY) ||
+ ((rsa->p != NULL) &&
+ (rsa->q != NULL) &&
+ (rsa->dmp1 != NULL) && (rsa->dmq1 != NULL) && (rsa->iqmp != NULL))) {
+ if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
+ goto err;
+ } else {
+ BIGNUM *d = BN_new();
+ if (d == NULL) {
+ RSAerr(RSA_F_RSA_OSSL_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+ BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
+
+ if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
+ if (!BN_MONT_CTX_set_locked
+ (&rsa->_method_mod_n, rsa->lock, rsa->n, ctx)) {
+ BN_free(d);
+ goto err;
+ }
+ if (!rsa->meth->bn_mod_exp(ret, f, 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);
+ }
+
+ if (blinding)
+ if (!rsa_blinding_invert(blinding, ret, unblind, ctx))
+ goto err;
+
+ p = buf;
+ j = BN_bn2bin(ret, p); /* j is only used with no-padding mode */
+
+ switch (padding) {
+ case RSA_PKCS1_PADDING:
+ r = RSA_padding_check_PKCS1_type_2(to, num, buf, j, num);
+ break;
+ case RSA_PKCS1_OAEP_PADDING:
+ r = RSA_padding_check_PKCS1_OAEP(to, num, buf, j, num, NULL, 0);
+ break;
+ 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);
+}
+
+#endif
projects / cassiopeia.git / blobdiff