/* crypto/dh/dh_key.c */
-/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
- *
+ *
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
+ *
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
- *
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
+ * 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
+ *
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
- *
+ *
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
*/
#include <stdio.h>
-#include "cryptlib.h"
-#include "bn.h"
-#include "rand.h"
-#include "dh.h"
-
-int DH_generate_key(dh)
-DH *dh;
- {
- int ok=0;
- unsigned int i;
- BN_CTX *ctx=NULL;
- BIGNUM *pub_key=NULL,*priv_key=NULL;
-
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
-
- if (dh->priv_key == NULL)
- {
- i=dh->length;
- if (i == 0)
- {
- /* Make the number p-1 bits long */
- i=BN_num_bits(dh->p)-1;
- }
- priv_key=BN_new();
- if (priv_key == NULL) goto err;
- if (!BN_rand(priv_key,i,0,0)) goto err;
- }
- else
- priv_key=dh->priv_key;
-
- if (dh->pub_key == NULL)
- {
- pub_key=BN_new();
- if (pub_key == NULL) goto err;
- }
- else
- pub_key=dh->pub_key;
-
- if (!BN_mod_exp(pub_key,dh->g,priv_key,dh->p,ctx)) goto err;
-
- dh->pub_key=pub_key;
- dh->priv_key=priv_key;
- ok=1;
-err:
- if (ok != 1)
- DHerr(DH_F_DH_GENERATE_KEY,ERR_R_BN_LIB);
-
- if ((pub_key != NULL) && (dh->pub_key == NULL)) BN_free(pub_key);
- if ((priv_key != NULL) && (dh->priv_key == NULL)) BN_free(priv_key);
- if (ctx != NULL) BN_CTX_free(ctx);
- return(ok);
- }
-
-int DH_compute_key(key,pub_key,dh)
-unsigned char *key;
-BIGNUM *pub_key;
-DH *dh;
- {
- BN_CTX *ctx;
- BIGNUM *tmp;
- int ret= -1;
-
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
- tmp=ctx->bn[ctx->tos++];
-
- if (dh->priv_key == NULL)
- {
- DHerr(DH_F_DH_COMPUTE_KEY,DH_R_NO_PRIVATE_VALUE);
- goto err;
- }
- if (!BN_mod_exp(tmp,pub_key,dh->priv_key,dh->p,ctx))
- {
- DHerr(DH_F_DH_COMPUTE_KEY,ERR_R_BN_LIB);
- goto err;
- }
-
- ret=BN_bn2bin(tmp,key);
-err:
- if (ctx != NULL) BN_CTX_free(ctx);
- return(ret);
- }
+#include "internal/cryptlib.h"
+#include <openssl/rand.h>
+#include <openssl/dh.h>
+#include "internal/bn_int.h"
+
+static int generate_key(DH *dh);
+static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh);
+static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
+ const BIGNUM *a, const BIGNUM *p,
+ const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
+static int dh_init(DH *dh);
+static int dh_finish(DH *dh);
+
+int DH_generate_key(DH *dh)
+{
+ return dh->meth->generate_key(dh);
+}
+
+int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
+{
+ return dh->meth->compute_key(key, pub_key, dh);
+}
+
+int DH_compute_key_padded(unsigned char *key, const BIGNUM *pub_key, DH *dh)
+{
+ int rv, pad;
+ rv = dh->meth->compute_key(key, pub_key, dh);
+ if (rv <= 0)
+ return rv;
+ pad = BN_num_bytes(dh->p) - rv;
+ if (pad > 0) {
+ memmove(key + pad, key, rv);
+ memset(key, 0, pad);
+ }
+ return rv + pad;
+}
+
+static DH_METHOD dh_ossl = {
+ "OpenSSL DH Method",
+ generate_key,
+ compute_key,
+ dh_bn_mod_exp,
+ dh_init,
+ dh_finish,
+ DH_FLAG_FIPS_METHOD,
+ NULL,
+ NULL
+};
+
+const DH_METHOD *DH_OpenSSL(void)
+{
+ return &dh_ossl;
+}
+
+static int generate_key(DH *dh)
+{
+ int ok = 0;
+ int generate_new_key = 0;
+ unsigned l;
+ BN_CTX *ctx;
+ BN_MONT_CTX *mont = NULL;
+ BIGNUM *pub_key = NULL, *priv_key = NULL;
+
+ ctx = BN_CTX_new();
+ if (ctx == NULL)
+ goto err;
+
+ if (dh->priv_key == NULL) {
+ priv_key = BN_secure_new();
+ if (priv_key == NULL)
+ goto err;
+ generate_new_key = 1;
+ } else
+ priv_key = dh->priv_key;
+
+ if (dh->pub_key == NULL) {
+ pub_key = BN_new();
+ if (pub_key == NULL)
+ goto err;
+ } else
+ pub_key = dh->pub_key;
+
+ if (dh->flags & DH_FLAG_CACHE_MONT_P) {
+ mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
+ CRYPTO_LOCK_DH, dh->p, ctx);
+ if (!mont)
+ goto err;
+ }
+
+ if (generate_new_key) {
+ if (dh->q) {
+ do {
+ if (!BN_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, 0, 0))
+ goto err;
+ }
+ }
+
+ {
+ BIGNUM *local_prk = NULL;
+ BIGNUM *prk;
+
+ if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) {
+ local_prk = prk = BN_new();
+ BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
+ } else
+ prk = priv_key;
+
+ if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, prk, dh->p, ctx, mont)) {
+ BN_free(local_prk);
+ goto err;
+ }
+ BN_free(local_prk);
+ }
+
+ dh->pub_key = pub_key;
+ dh->priv_key = priv_key;
+ ok = 1;
+ err:
+ if (ok != 1)
+ DHerr(DH_F_GENERATE_KEY, ERR_R_BN_LIB);
+
+ if (pub_key != dh->pub_key)
+ BN_free(pub_key);
+ if (priv_key != dh->priv_key)
+ BN_free(priv_key);
+ BN_CTX_free(ctx);
+ return (ok);
+}
+
+static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
+{
+ BN_CTX *ctx = NULL;
+ BN_MONT_CTX *mont = NULL;
+ BIGNUM *tmp;
+ int ret = -1;
+ int check_result;
+
+ if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
+ DHerr(DH_F_COMPUTE_KEY, DH_R_MODULUS_TOO_LARGE);
+ goto err;
+ }
+
+ ctx = BN_CTX_new();
+ if (ctx == NULL)
+ goto err;
+ BN_CTX_start(ctx);
+ tmp = BN_CTX_get(ctx);
+
+ if (dh->priv_key == NULL) {
+ DHerr(DH_F_COMPUTE_KEY, DH_R_NO_PRIVATE_VALUE);
+ goto err;
+ }
+
+ if (dh->flags & DH_FLAG_CACHE_MONT_P) {
+ mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
+ CRYPTO_LOCK_DH, dh->p, ctx);
+ if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) {
+ /* XXX */
+ BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
+ }
+ if (!mont)
+ goto err;
+ }
+
+ if (!DH_check_pub_key(dh, pub_key, &check_result) || check_result) {
+ DHerr(DH_F_COMPUTE_KEY, DH_R_INVALID_PUBKEY);
+ goto err;
+ }
+
+ if (!dh->
+ meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key, dh->p, ctx, mont)) {
+ DHerr(DH_F_COMPUTE_KEY, ERR_R_BN_LIB);
+ goto err;
+ }
+
+ ret = BN_bn2bin(tmp, key);
+ err:
+ if (ctx != NULL) {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
+ return (ret);
+}
+
+static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
+ const BIGNUM *a, const BIGNUM *p,
+ const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
+{
+ /*
+ * If a is only one word long and constant time is false, use the faster
+ * exponenentiation function.
+ */
+ if (bn_get_top(a) == 1 && ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) != 0)) {
+ BN_ULONG A = bn_get_words(a)[0];
+ return BN_mod_exp_mont_word(r, A, p, m, ctx, m_ctx);
+ } else
+ return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
+}
+
+static int dh_init(DH *dh)
+{
+ dh->flags |= DH_FLAG_CACHE_MONT_P;
+ return (1);
+}
+
+static int dh_finish(DH *dh)
+{
+ BN_MONT_CTX_free(dh->method_mont_p);
+ return (1);
+}
projects / openssl.git / blobdiff