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authorMatt Johnston <matt@ucc.asn.au>2007-01-11 03:14:55 +0000
committerMatt Johnston <matt@ucc.asn.au>2007-01-11 03:14:55 +0000
commit9d5ed350a749368c84254c11e7616ce3c891193a (patch)
tree6dacbff2e9f5c60a1568382db55c72dd6d2ce925 /common-algo.c
parentca52f070aecf91e75f6ae6c87d4ae1a2189ccb14 (diff)
parent5ea605d8de5b4438deb4fa86c5231710dd09f934 (diff)
propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 2af95f00ebd5bb7a28b3817db1218442c935388e)
to branch 'au.asn.ucc.matt.dropbear' (head ecd779509ef23a8cdf64888904fc9b31d78aa933) --HG-- extra : convert_revision : d26d5eb2837f46b56a33fb0e7573aa0201abd4d5
Diffstat (limited to 'common-algo.c')
-rw-r--r--common-algo.c228
1 files changed, 228 insertions, 0 deletions
diff --git a/common-algo.c b/common-algo.c
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+/*
+ * 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);
+}