--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common-algo.c	Wed Mar 08 13:23:58 2006 +0000
@@ -0,0 +1,228 @@
+/*
+ * Dropbear SSH
+ * 
+ * Copyright (c) 2002,2003 Matt Johnston
+ * Copyright (c) 2004 by Mihnea Stoenescu
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#include "algo.h"
+#include "dbutil.h"
+
+/* This file (algo.c) organises the ciphers which can be used, and is used to
+ * decide which ciphers/hashes/compression/signing to use during key exchange*/
+
+/* Mappings for ciphers, parameters are
+   {&cipher_desc, keysize, blocksize} */
+
+#ifdef DROPBEAR_AES256_CBC
+static const struct dropbear_cipher dropbear_aes256 = 
+	{&aes_desc, 32, 16};
+#endif
+#ifdef DROPBEAR_AES128_CBC
+static const struct dropbear_cipher dropbear_aes128 = 
+	{&aes_desc, 16, 16};
+#endif
+#ifdef DROPBEAR_BLOWFISH_CBC
+static const struct dropbear_cipher dropbear_blowfish = 
+	{&blowfish_desc, 16, 8};
+#endif
+#ifdef DROPBEAR_TWOFISH256_CBC
+static const struct dropbear_cipher dropbear_twofish256 = 
+	{&twofish_desc, 32, 16};
+#endif
+#ifdef DROPBEAR_TWOFISH128_CBC
+static const struct dropbear_cipher dropbear_twofish128 = 
+	{&twofish_desc, 16, 16};
+#endif
+#ifdef DROPBEAR_3DES_CBC
+static const struct dropbear_cipher dropbear_3des = 
+	{&des3_desc, 24, 8};
+#endif
+
+/* used to indicate no encryption, as defined in rfc2410 */
+const struct dropbear_cipher dropbear_nocipher =
+	{NULL, 16, 8}; 
+
+/* Mapping of ssh hashes to libtomcrypt hashes, including keysize etc.
+   {&hash_desc, keysize, hashsize} */
+
+#ifdef DROPBEAR_SHA1_HMAC
+static const struct dropbear_hash dropbear_sha1 = 
+	{&sha1_desc, 20, 20};
+#endif
+#ifdef DROPBEAR_SHA1_96_HMAC
+static const struct dropbear_hash dropbear_sha1_96 = 
+	{&sha1_desc, 20, 12};
+#endif
+#ifdef DROPBEAR_MD5_HMAC
+static const struct dropbear_hash dropbear_md5 = 
+	{&md5_desc, 16, 16};
+#endif
+
+const struct dropbear_hash dropbear_nohash =
+	{NULL, 16, 0}; /* used initially */
+	
+
+/* The following map ssh names to internal values */
+
+algo_type sshciphers[] = {
+#ifdef DROPBEAR_AES128_CBC
+	{"aes128-cbc", 0, (void*)&dropbear_aes128, 1},
+#endif
+#ifdef DROPBEAR_3DES_CBC
+	{"3des-cbc", 0, (void*)&dropbear_3des, 1},
+#endif
+#ifdef DROPBEAR_AES256_CBC
+	{"aes256-cbc", 0, (void*)&dropbear_aes256, 1},
+#endif
+#ifdef DROPBEAR_TWOFISH256_CBC
+	{"twofish256-cbc", 0, (void*)&dropbear_twofish256, 1},
+	{"twofish-cbc", 0, (void*)&dropbear_twofish256, 1},
+#endif
+#ifdef DROPBEAR_TWOFISH128_CBC
+	{"twofish128-cbc", 0, (void*)&dropbear_twofish128, 1},
+#endif
+#ifdef DROPBEAR_BLOWFISH_CBC
+	{"blowfish-cbc", 0, (void*)&dropbear_blowfish, 1},
+#endif
+	{NULL, 0, NULL, 0}
+};
+
+algo_type sshhashes[] = {
+#ifdef DROPBEAR_SHA1_96_HMAC
+	{"hmac-sha1-96", 0, (void*)&dropbear_sha1_96, 1},
+#endif
+#ifdef DROPBEAR_SHA1_HMAC
+	{"hmac-sha1", 0, (void*)&dropbear_sha1, 1},
+#endif
+#ifdef DROPBEAR_MD5_HMAC
+	{"hmac-md5", 0, (void*)&dropbear_md5, 1},
+#endif
+	{NULL, 0, NULL, 0}
+};
+
+algo_type sshcompress[] = {
+#ifndef DISABLE_ZLIB
+	{"zlib", DROPBEAR_COMP_ZLIB, NULL, 1},
+#endif
+	{"none", DROPBEAR_COMP_NONE, NULL, 1},
+	{NULL, 0, NULL, 0}
+};
+
+algo_type sshhostkey[] = {
+#ifdef DROPBEAR_RSA
+	{"ssh-rsa", DROPBEAR_SIGNKEY_RSA, NULL, 1},
+#endif
+#ifdef DROPBEAR_DSS
+	{"ssh-dss", DROPBEAR_SIGNKEY_DSS, NULL, 1},
+#endif
+	{NULL, 0, NULL, 0}
+};
+
+algo_type sshkex[] = {
+	{"diffie-hellman-group1-sha1", DROPBEAR_KEX_DH_GROUP1, NULL, 1},
+	{NULL, 0, NULL, 0}
+};
+
+
+/* Register the compiled in ciphers.
+ * This should be run before using any of the ciphers/hashes */
+void crypto_init() {
+
+	const struct ltc_cipher_descriptor *regciphers[] = {
+#ifdef DROPBEAR_AES_CBC
+		&aes_desc,
+#endif
+#ifdef DROPBEAR_BLOWFISH_CBC
+		&blowfish_desc,
+#endif
+#ifdef DROPBEAR_TWOFISH_CBC
+		&twofish_desc,
+#endif
+#ifdef DROPBEAR_3DES_CBC
+		&des3_desc,
+#endif
+		NULL
+	};
+
+	const struct ltc_hash_descriptor *reghashes[] = {
+		/* we need sha1 for hostkey stuff regardless */
+		&sha1_desc,
+#ifdef DROPBEAR_MD5_HMAC
+		&md5_desc,
+#endif
+		NULL
+	};	
+	int i;
+	
+	for (i = 0; regciphers[i] != NULL; i++) {
+		if (register_cipher(regciphers[i]) == -1) {
+			dropbear_exit("error registering crypto");
+		}
+	}
+
+	for (i = 0; reghashes[i] != NULL; i++) {
+		if (register_hash(reghashes[i]) == -1) {
+			dropbear_exit("error registering crypto");
+		}
+	}
+}
+
+/* algolen specifies the length of algo, algos is our local list to match
+ * against.
+ * Returns DROPBEAR_SUCCESS if we have a match for algo, DROPBEAR_FAILURE
+ * otherwise */
+int have_algo(char* algo, size_t algolen, algo_type algos[]) {
+
+	int i;
+
+	for (i = 0; algos[i].name != NULL; i++) {
+		if (strlen(algos[i].name) == algolen
+				&& (strncmp(algos[i].name, algo, algolen) == 0)) {
+			return DROPBEAR_SUCCESS;
+		}
+	}
+
+	return DROPBEAR_FAILURE;
+}
+
+
+
+/* Output a comma separated list of algorithms to a buffer */
+void buf_put_algolist(buffer * buf, algo_type localalgos[]) {
+
+	unsigned int i, len;
+	unsigned int donefirst = 0;
+	buffer *algolist = NULL;
+
+	algolist = buf_new(100);
+	for (i = 0; localalgos[i].name != NULL; i++) {
+		if (localalgos[i].usable) {
+			if (donefirst)
+				buf_putbyte(algolist, ',');
+			donefirst = 1;
+			len = strlen(localalgos[i].name);
+			buf_putbytes(algolist, localalgos[i].name, len);
+		}
+	}
+	buf_putstring(buf, algolist->data, algolist->len);
+	buf_free(algolist);
+}