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comparison cli_algo.c @ 4:fe6bca95afa7

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Makefile.in contains updated files required
author Matt Johnston <matt@ucc.asn.au>
date Tue, 01 Jun 2004 02:46:09 +0000
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-1:000000000000 4:fe6bca95afa7
1 /*
2 * Dropbear - a SSH2 server
3 * SSH client implementation
4 *
5 * Copyright (c) 2002,2003 Matt Johnston
6 * Copyright (c) 2004 by Mihnea Stoenescu
7 * All rights reserved.
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
22 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
25 * SOFTWARE. */
26
27 #include "algo.h"
28 #include "dbutil.h"
29
30
31 /*
32 * The chosen [encryption | MAC | compression] algorithm to each
33 * direction MUST be the first algorithm on the client's list
34 * that is also on the server's list.
35 */
36 algo_type * cli_buf_match_algo(buffer* buf, algo_type localalgos[]) {
37
38 unsigned char * algolist = NULL;
39 unsigned char * remotealgos[MAX_PROPOSED_ALGO];
40 unsigned int len;
41 unsigned int count, i, j;
42 algo_type * ret = NULL;
43
44 /* get the comma-separated list from the buffer ie "algo1,algo2,algo3" */
45 algolist = buf_getstring(buf, &len);
46 TRACE(("cli_buf_match_algo: %s", algolist));
47 if (len > MAX_PROPOSED_ALGO*(MAX_NAME_LEN+1)) {
48 goto out; /* just a sanity check, no other use */
49 }
50
51 /* remotealgos will contain a list of the strings parsed out */
52 /* We will have at least one string (even if it's just "") */
53 remotealgos[0] = algolist;
54 count = 1;
55 /* Iterate through, replacing ','s with NULs, to split it into
56 * words. */
57 for (i = 0; i < len; i++) {
58 if (algolist[i] == '\0') {
59 /* someone is trying something strange */
60 goto out;
61 }
62 if (algolist[i] == ',') {
63 algolist[i] = '\0';
64 remotealgos[count] = &algolist[i+1];
65 count++;
66 }
67 if (count == MAX_PROPOSED_ALGO) {
68 break;
69 }
70 }
71
72 /* iterate and find the first match */
73
74 for (j = 0; localalgos[j].name != NULL; j++) {
75 if (localalgos[j].usable) {
76 len = strlen(localalgos[j].name);
77 for (i = 0; i < count; i++) {
78 if (len == strlen(remotealgos[i])
79 && strncmp(localalgos[j].name,
80 remotealgos[i], len) == 0) {
81 ret = &localalgos[j];
82 goto out;
83 }
84 }
85 }
86 }
87
88 out:
89 m_free(algolist);
90 return ret;
91 }
92