add ltm dh

lib/hcrypto/Makefile.am

@@ -109,6 +109,7 @@ libhcrypto_la_SOURCES =	\
 	dh.h		\
 	dh-imath.c	\
 	dh-tfm.c	\
+	dh-ltm.c	\
 	dsa.c		\
 	dsa.h		\
 	doxygen.c	\

lib/hcrypto/dh-ltm.c

@@ -0,0 +1,249 @@
+/*
+ * Copyright (c) 2006 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ *
+ * 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 above 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. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <dh.h>
+
+#include <roken.h>
+
+#include "tommath.h"
+
+static void
+BN2mpz(mp_int *s, const BIGNUM *bn)
+{
+    size_t len;
+    void *p;
+
+    len = BN_num_bytes(bn);
+    p = malloc(len);
+    BN_bn2bin(bn, p);
+    mp_read_unsigned_bin(s, p, len);
+    free(p);
+}
+
+
+static BIGNUM *
+mpz2BN(mp_int *s)
+{
+    size_t size;
+    BIGNUM *bn;
+    void *p;
+
+    size = mp_unsigned_bin_size(s);
+    p = malloc(size);
+    if (p == NULL && size != 0)
+	return NULL;
+    mp_to_unsigned_bin(s, p);
+
+    bn = BN_bin2bn(p, size, NULL);
+    free(p);
+    return bn;
+}
+
+/*
+ *
+ */
+
+#define DH_NUM_TRIES 10
+
+static int
+ltm_dh_generate_key(DH *dh)
+{
+    mp_int pub, priv_key, g, p;
+    int have_private_key = (dh->priv_key != NULL);
+    int codes, times = 0;
+    int res;
+
+    if (dh->p == NULL || dh->g == NULL)
+	return 0;
+
+    while (times++ < DH_NUM_TRIES) {
+	if (!have_private_key) {
+	    size_t bits = BN_num_bits(dh->p);
+
+	    if (dh->priv_key)
+		BN_free(dh->priv_key);
+
+	    dh->priv_key = BN_new();
+	    if (dh->priv_key == NULL)
+		return 0;
+	    if (!BN_rand(dh->priv_key, bits - 1, 0, 0)) {
+		BN_clear_free(dh->priv_key);
+		dh->priv_key = NULL;
+		return 0;
+	    }
+	}
+	if (dh->pub_key)
+	    BN_free(dh->pub_key);
+
+	mp_init_multi(&pub, &priv_key, &g, &p, NULL);
+	
+	BN2mpz(&priv_key, dh->priv_key);
+	BN2mpz(&g, dh->g);
+	BN2mpz(&p, dh->p);
+	
+	res = mp_exptmod(&g, &priv_key, &p, &pub);
+
+	mp_zero(&priv_key);
+	mp_zero(&g);
+	mp_zero(&p);
+	if (res != 0)
+	    continue;
+
+	dh->pub_key = mpz2BN(&pub);
+	mp_zero(&pub);
+	if (dh->pub_key == NULL)
+	    return 0;
+	
+	if (DH_check_pubkey(dh, dh->pub_key, &codes) && codes == 0)
+	    break;
+	if (have_private_key)
+	    return 0;
+    }
+
+    if (times >= DH_NUM_TRIES) {
+	if (!have_private_key && dh->priv_key) {
+	    BN_free(dh->priv_key);
+	    dh->priv_key = NULL;
+	}
+	if (dh->pub_key) {
+	    BN_free(dh->pub_key);
+	    dh->pub_key = NULL;
+	}
+	return 0;
+    }
+
+    return 1;
+}
+
+static int
+ltm_dh_compute_key(unsigned char *shared, const BIGNUM * pub, DH *dh)
+{
+    mp_int s, priv_key, p, peer_pub;
+    size_t size = 0;
+    int ret;
+
+    if (dh->pub_key == NULL || dh->g == NULL || dh->priv_key == NULL)
+	return -1;
+
+    mp_init(&p);
+    BN2mpz(&p, dh->p);
+
+    mp_init(&peer_pub);
+    BN2mpz(&peer_pub, pub);
+
+    /* check if peers pubkey is reasonable */
+    if (mp_isneg(&peer_pub)
+	|| mp_cmp(&peer_pub, &p) >= 0
+	|| mp_cmp_d(&peer_pub, 1) <= 0)
+    {
+	mp_zero(&p);
+	mp_zero(&peer_pub);
+	return -1;
+    }
+
+    mp_init(&priv_key);
+    BN2mpz(&priv_key, dh->priv_key);
+
+    mp_init(&s);
+
+    ret = mp_exptmod(&peer_pub, &priv_key, &p, &s);
+
+    mp_zero(&p);
+    mp_zero(&peer_pub);
+    mp_zero(&priv_key);
+
+    if (ret != 0)
+	return -1;
+
+    size = mp_unsigned_bin_size(&s);
+    mp_to_unsigned_bin(&s, shared);
+    mp_zero(&s);
+
+    return size;
+}
+
+static int
+ltm_dh_generate_params(DH *dh, int a, int b, BN_GENCB *callback)
+{
+    /* groups should already be known, we don't care about this */
+    return 0;
+}
+
+static int
+ltm_dh_init(DH *dh)
+{
+    return 1;
+}
+
+static int
+ltm_dh_finish(DH *dh)
+{
+    return 1;
+}
+
+
+/*
+ *
+ */
+
+const DH_METHOD _hc_dh_ltm_method = {
+    "hcrypto ltm DH",
+    ltm_dh_generate_key,
+    ltm_dh_compute_key,
+    NULL,
+    ltm_dh_init,
+    ltm_dh_finish,
+    0,
+    NULL,
+    ltm_dh_generate_params
+};
+
+/**
+ * DH implementation using libimath.
+ *
+ * @return the DH_METHOD for the DH implementation using libimath.
+ *
+ * @ingroup hcrypto_dh
+ */
+
+const DH_METHOD *
+DH_ltm_method(void)
+{
+    return &_hc_dh_ltm_method;
+}

lib/hcrypto/dh.h

@@ -42,6 +42,7 @@
 #define DH_null_method hc_DH_null_method
 #define DH_imath_method hc_DH_imath_method
 #define DH_tfm_method hc_DH_tfm_method
+#define DH_ltm_method hc_DH_ltm_method
 #define DH_new hc_DH_new
 #define DH_new_method hc_DH_new_method
 #define DH_free hc_DH_free
@@ -117,6 +118,7 @@ struct DH {
 
 const DH_METHOD *DH_null_method(void);
 const DH_METHOD *DH_tfm_method(void);
+const DH_METHOD *DH_ltm_method(void);
 const DH_METHOD *DH_imath_method(void);
 
 DH *	DH_new(void);

lib/hcrypto/engine.c

@@ -274,9 +274,7 @@ ENGINE_load_builtin_engines(void)
     ENGINE_set_name(engine,
 		    "Heimdal crypto ltm engine version " PACKAGE_VERSION);
     ENGINE_set_RSA(engine, RSA_ltm_method());
-#if 0
     ENGINE_set_DH(engine, DH_ltm_method());
-#endif
 
     ret = add_engine(engine);
     if (ret != 1)