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-rw-r--r--openssl/crypto/dh/dh_key.c263
1 files changed, 263 insertions, 0 deletions
diff --git a/openssl/crypto/dh/dh_key.c b/openssl/crypto/dh/dh_key.c
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+/* crypto/dh/dh_key.c */
+/* 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:
+ * 1. Redistributions of source code must retain the copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * "This product includes cryptographic software written by
+ * 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
+ * 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
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * 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
+ * [including the GNU Public Licence.]
+ */
+
+#include <stdio.h>
+#include "cryptlib.h"
+#include <openssl/bn.h>
+#include <openssl/rand.h>
+#include <openssl/dh.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);
+ }
+
+static DH_METHOD dh_ossl = {
+"OpenSSL DH Method",
+generate_key,
+compute_key,
+dh_bn_mod_exp,
+dh_init,
+dh_finish,
+0,
+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_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)
+ {
+ l = dh->length ? dh->length : BN_num_bits(dh->p)-1; /* secret exponent length */
+ if (!BN_rand(priv_key, l, 0, 0)) goto err;
+ }
+
+ {
+ BIGNUM local_prk;
+ BIGNUM *prk;
+
+ if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0)
+ {
+ BN_init(&local_prk);
+ prk = &local_prk;
+ 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)) goto err;
+ }
+
+ 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 != NULL) && (dh->pub_key == NULL)) BN_free(pub_key);
+ if ((priv_key != NULL) && (dh->priv_key == NULL)) 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 (a->top == 1 && ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) != 0))
+ {
+ BN_ULONG A = a->d[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)
+ {
+ if(dh->method_mont_p)
+ BN_MONT_CTX_free(dh->method_mont_p);
+ return(1);
+ }