/*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
*
- * Licensed under the OpenSSL license (the "License"). You may not use
+ * Licensed under the Apache License 2.0 (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 "internal/cryptlib.h"
-#include "dh_locl.h"
-#include "internal/bn_int.h"
+#include "dh_local.h"
+#include "crypto/bn.h"
static int generate_key(DH *dh);
static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh);
NULL
};
+static const DH_METHOD *default_DH_method = &dh_ossl;
+
const DH_METHOD *DH_OpenSSL(void)
{
return &dh_ossl;
}
+void DH_set_default_method(const DH_METHOD *meth)
+{
+ default_DH_method = meth;
+}
+
+const DH_METHOD *DH_get_default_method(void)
+{
+ return default_DH_method;
+}
+
static int generate_key(DH *dh)
{
int ok = 0;
int generate_new_key = 0;
unsigned l;
- BN_CTX *ctx;
+ BN_CTX *ctx = NULL;
BN_MONT_CTX *mont = NULL;
BIGNUM *pub_key = NULL, *priv_key = NULL;
+ if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
+ DHerr(DH_F_GENERATE_KEY, DH_R_MODULUS_TOO_LARGE);
+ return 0;
+ }
+
+ if (BN_num_bits(dh->p) < DH_MIN_MODULUS_BITS) {
+ DHerr(DH_F_GENERATE_KEY, DH_R_MODULUS_TOO_SMALL);
+ return 0;
+ }
+
ctx = BN_CTX_new();
if (ctx == NULL)
goto err;
if (generate_new_key) {
if (dh->q) {
do {
- if (!BN_rand_range(priv_key, dh->q))
+ if (!BN_priv_rand_range(priv_key, dh->q))
goto err;
}
while (BN_is_zero(priv_key) || BN_is_one(priv_key));
} else {
/* secret exponent length */
l = dh->length ? dh->length : BN_num_bits(dh->p) - 1;
- if (!BN_rand(priv_key, l, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY))
+ if (!BN_priv_rand(priv_key, l, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY))
goto err;
+ /*
+ * We handle just one known case where g is a quadratic non-residue:
+ * for g = 2: p % 8 == 3
+ */
+ if (BN_is_word(dh->g, DH_GENERATOR_2) && !BN_is_bit_set(dh->p, 2)) {
+ /* clear bit 0, since it won't be a secret anyway */
+ if (!BN_clear_bit(priv_key, 0))
+ goto err;
+ }
}
}
BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, prk, dh->p, ctx, mont)) {
- BN_free(prk);
+ BN_clear_free(prk);
goto err;
}
/* We MUST free prk before any further use of priv_key */
- BN_free(prk);
+ BN_clear_free(prk);
}
dh->pub_key = pub_key;
dh->priv_key = priv_key;
+ dh->dirty_cnt++;
ok = 1;
err:
if (ok != 1)
if (priv_key != dh->priv_key)
BN_free(priv_key);
BN_CTX_free(ctx);
- return (ok);
+ return ok;
}
static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
goto err;
}
+ if (BN_num_bits(dh->p) < DH_MIN_MODULUS_BITS) {
+ DHerr(DH_F_COMPUTE_KEY, DH_R_MODULUS_TOO_SMALL);
+ return 0;
+ }
+
ctx = BN_CTX_new();
if (ctx == NULL)
goto err;
ret = BN_bn2bin(tmp, key);
err:
- if (ctx != NULL) {
- BN_CTX_end(ctx);
- BN_CTX_free(ctx);
- }
- return (ret);
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ return ret;
}
static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
static int dh_init(DH *dh)
{
dh->flags |= DH_FLAG_CACHE_MONT_P;
- return (1);
+ return 1;
}
static int dh_finish(DH *dh)
{
BN_MONT_CTX_free(dh->method_mont_p);
- return (1);
+ return 1;
+}
+
+int dh_buf2key(DH *dh, const unsigned char *buf, size_t len)
+{
+ int err_reason = DH_R_BN_ERROR;
+ BIGNUM *pubkey = NULL;
+ const BIGNUM *p;
+ size_t p_size;
+
+ if ((pubkey = BN_bin2bn(buf, len, NULL)) == NULL)
+ goto err;
+ DH_get0_pqg(dh, &p, NULL, NULL);
+ if (p == NULL || (p_size = BN_num_bytes(p)) == 0) {
+ err_reason = DH_R_NO_PARAMETERS_SET;
+ goto err;
+ }
+ /*
+ * As per Section 4.2.8.1 of RFC 8446 fail if DHE's
+ * public key is of size not equal to size of p
+ */
+ if (BN_is_zero(pubkey) || p_size != len) {
+ err_reason = DH_R_INVALID_PUBKEY;
+ goto err;
+ }
+ if (DH_set0_key(dh, pubkey, NULL) != 1)
+ goto err;
+ return 1;
+err:
+ DHerr(DH_F_DH_BUF2KEY, err_reason);
+ BN_free(pubkey);
+ return 0;
+}
+
+size_t dh_key2buf(const DH *dh, unsigned char **pbuf_out)
+{
+ const BIGNUM *pubkey;
+ unsigned char *pbuf;
+ const BIGNUM *p;
+ int p_size;
+
+ DH_get0_pqg(dh, &p, NULL, NULL);
+ DH_get0_key(dh, &pubkey, NULL);
+ if (p == NULL || pubkey == NULL
+ || (p_size = BN_num_bytes(p)) == 0
+ || BN_num_bytes(pubkey) == 0) {
+ DHerr(DH_F_DH_KEY2BUF, DH_R_INVALID_PUBKEY);
+ return 0;
+ }
+ if ((pbuf = OPENSSL_malloc(p_size)) == NULL) {
+ DHerr(DH_F_DH_KEY2BUF, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+ /*
+ * As per Section 4.2.8.1 of RFC 8446 left pad public
+ * key with zeros to the size of p
+ */
+ if (BN_bn2binpad(pubkey, pbuf, p_size) < 0) {
+ OPENSSL_free(pbuf);
+ DHerr(DH_F_DH_KEY2BUF, DH_R_BN_ERROR);
+ return 0;
+ }
+ *pbuf_out = pbuf;
+ return p_size;
}