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comparison common-algo.c @ 285:1b9e69c058d2

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propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 20dccfc09627970a312d77fb41dc2970b62689c3) to branch 'au.asn.ucc.matt.dropbear' (head fdf4a7a3b97ae5046139915de7e40399cceb2c01)
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 13:23:58 +0000
parents 89ace56293f6
children 64abb124763d 0e69e948caba
comparison
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281:997e6f7dc01e 285:1b9e69c058d2
1 /*
2 * Dropbear SSH
3 *
4 * Copyright (c) 2002,2003 Matt Johnston
5 * Copyright (c) 2004 by Mihnea Stoenescu
6 * All rights reserved.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
24 * SOFTWARE. */
25
26 #include "algo.h"
27 #include "dbutil.h"
28
29 /* This file (algo.c) organises the ciphers which can be used, and is used to
30 * decide which ciphers/hashes/compression/signing to use during key exchange*/
31
32 /* Mappings for ciphers, parameters are
33 {&cipher_desc, keysize, blocksize} */
34
35 #ifdef DROPBEAR_AES256_CBC
36 static const struct dropbear_cipher dropbear_aes256 =
37 {&aes_desc, 32, 16};
38 #endif
39 #ifdef DROPBEAR_AES128_CBC
40 static const struct dropbear_cipher dropbear_aes128 =
41 {&aes_desc, 16, 16};
42 #endif
43 #ifdef DROPBEAR_BLOWFISH_CBC
44 static const struct dropbear_cipher dropbear_blowfish =
45 {&blowfish_desc, 16, 8};
46 #endif
47 #ifdef DROPBEAR_TWOFISH256_CBC
48 static const struct dropbear_cipher dropbear_twofish256 =
49 {&twofish_desc, 32, 16};
50 #endif
51 #ifdef DROPBEAR_TWOFISH128_CBC
52 static const struct dropbear_cipher dropbear_twofish128 =
53 {&twofish_desc, 16, 16};
54 #endif
55 #ifdef DROPBEAR_3DES_CBC
56 static const struct dropbear_cipher dropbear_3des =
57 {&des3_desc, 24, 8};
58 #endif
59
60 /* used to indicate no encryption, as defined in rfc2410 */
61 const struct dropbear_cipher dropbear_nocipher =
62 {NULL, 16, 8};
63
64 /* Mapping of ssh hashes to libtomcrypt hashes, including keysize etc.
65 {&hash_desc, keysize, hashsize} */
66
67 #ifdef DROPBEAR_SHA1_HMAC
68 static const struct dropbear_hash dropbear_sha1 =
69 {&sha1_desc, 20, 20};
70 #endif
71 #ifdef DROPBEAR_SHA1_96_HMAC
72 static const struct dropbear_hash dropbear_sha1_96 =
73 {&sha1_desc, 20, 12};
74 #endif
75 #ifdef DROPBEAR_MD5_HMAC
76 static const struct dropbear_hash dropbear_md5 =
77 {&md5_desc, 16, 16};
78 #endif
79
80 const struct dropbear_hash dropbear_nohash =
81 {NULL, 16, 0}; /* used initially */
82
83
84 /* The following map ssh names to internal values */
85
86 algo_type sshciphers[] = {
87 #ifdef DROPBEAR_AES128_CBC
88 {"aes128-cbc", 0, (void*)&dropbear_aes128, 1},
89 #endif
90 #ifdef DROPBEAR_3DES_CBC
91 {"3des-cbc", 0, (void*)&dropbear_3des, 1},
92 #endif
93 #ifdef DROPBEAR_AES256_CBC
94 {"aes256-cbc", 0, (void*)&dropbear_aes256, 1},
95 #endif
96 #ifdef DROPBEAR_TWOFISH256_CBC
97 {"twofish256-cbc", 0, (void*)&dropbear_twofish256, 1},
98 {"twofish-cbc", 0, (void*)&dropbear_twofish256, 1},
99 #endif
100 #ifdef DROPBEAR_TWOFISH128_CBC
101 {"twofish128-cbc", 0, (void*)&dropbear_twofish128, 1},
102 #endif
103 #ifdef DROPBEAR_BLOWFISH_CBC
104 {"blowfish-cbc", 0, (void*)&dropbear_blowfish, 1},
105 #endif
106 {NULL, 0, NULL, 0}
107 };
108
109 algo_type sshhashes[] = {
110 #ifdef DROPBEAR_SHA1_96_HMAC
111 {"hmac-sha1-96", 0, (void*)&dropbear_sha1_96, 1},
112 #endif
113 #ifdef DROPBEAR_SHA1_HMAC
114 {"hmac-sha1", 0, (void*)&dropbear_sha1, 1},
115 #endif
116 #ifdef DROPBEAR_MD5_HMAC
117 {"hmac-md5", 0, (void*)&dropbear_md5, 1},
118 #endif
119 {NULL, 0, NULL, 0}
120 };
121
122 algo_type sshcompress[] = {
123 #ifndef DISABLE_ZLIB
124 {"zlib", DROPBEAR_COMP_ZLIB, NULL, 1},
125 #endif
126 {"none", DROPBEAR_COMP_NONE, NULL, 1},
127 {NULL, 0, NULL, 0}
128 };
129
130 algo_type sshhostkey[] = {
131 #ifdef DROPBEAR_RSA
132 {"ssh-rsa", DROPBEAR_SIGNKEY_RSA, NULL, 1},
133 #endif
134 #ifdef DROPBEAR_DSS
135 {"ssh-dss", DROPBEAR_SIGNKEY_DSS, NULL, 1},
136 #endif
137 {NULL, 0, NULL, 0}
138 };
139
140 algo_type sshkex[] = {
141 {"diffie-hellman-group1-sha1", DROPBEAR_KEX_DH_GROUP1, NULL, 1},
142 {NULL, 0, NULL, 0}
143 };
144
145
146 /* Register the compiled in ciphers.
147 * This should be run before using any of the ciphers/hashes */
148 void crypto_init() {
149
150 const struct ltc_cipher_descriptor *regciphers[] = {
151 #ifdef DROPBEAR_AES_CBC
152 &aes_desc,
153 #endif
154 #ifdef DROPBEAR_BLOWFISH_CBC
155 &blowfish_desc,
156 #endif
157 #ifdef DROPBEAR_TWOFISH_CBC
158 &twofish_desc,
159 #endif
160 #ifdef DROPBEAR_3DES_CBC
161 &des3_desc,
162 #endif
163 NULL
164 };
165
166 const struct ltc_hash_descriptor *reghashes[] = {
167 /* we need sha1 for hostkey stuff regardless */
168 &sha1_desc,
169 #ifdef DROPBEAR_MD5_HMAC
170 &md5_desc,
171 #endif
172 NULL
173 };
174 int i;
175
176 for (i = 0; regciphers[i] != NULL; i++) {
177 if (register_cipher(regciphers[i]) == -1) {
178 dropbear_exit("error registering crypto");
179 }
180 }
181
182 for (i = 0; reghashes[i] != NULL; i++) {
183 if (register_hash(reghashes[i]) == -1) {
184 dropbear_exit("error registering crypto");
185 }
186 }
187 }
188
189 /* algolen specifies the length of algo, algos is our local list to match
190 * against.
191 * Returns DROPBEAR_SUCCESS if we have a match for algo, DROPBEAR_FAILURE
192 * otherwise */
193 int have_algo(char* algo, size_t algolen, algo_type algos[]) {
194
195 int i;
196
197 for (i = 0; algos[i].name != NULL; i++) {
198 if (strlen(algos[i].name) == algolen
199 && (strncmp(algos[i].name, algo, algolen) == 0)) {
200 return DROPBEAR_SUCCESS;
201 }
202 }
203
204 return DROPBEAR_FAILURE;
205 }
206
207
208
209 /* Output a comma separated list of algorithms to a buffer */
210 void buf_put_algolist(buffer * buf, algo_type localalgos[]) {
211
212 unsigned int i, len;
213 unsigned int donefirst = 0;
214 buffer *algolist = NULL;
215
216 algolist = buf_new(100);
217 for (i = 0; localalgos[i].name != NULL; i++) {
218 if (localalgos[i].usable) {
219 if (donefirst)
220 buf_putbyte(algolist, ',');
221 donefirst = 1;
222 len = strlen(localalgos[i].name);
223 buf_putbytes(algolist, localalgos[i].name, len);
224 }
225 }
226 buf_putstring(buf, algolist->data, algolist->len);
227 buf_free(algolist);
228 }