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Damien Miller450a7a12000-03-26 13:04:51 +10001/*
2 * Copyright (c) 2000 Markus Friedl. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed by Markus Friedl.
15 * 4. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29/*
30 * read_bignum():
31 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
32 */
33
34#include "includes.h"
Damien Miller5f056372000-04-16 12:31:48 +100035#include "ssh.h"
Damien Miller450a7a12000-03-26 13:04:51 +100036#include <openssl/rsa.h>
37#include <openssl/dsa.h>
38#include <openssl/evp.h>
Damien Miller450a7a12000-03-26 13:04:51 +100039#include "xmalloc.h"
40#include "key.h"
Damien Millereba71ba2000-04-29 23:57:08 +100041#include "dsa.h"
42#include "uuencode.h"
43
44#define SSH_DSS "ssh-dss"
Damien Miller450a7a12000-03-26 13:04:51 +100045
46Key *
47key_new(int type)
48{
49 Key *k;
50 RSA *rsa;
51 DSA *dsa;
52 k = xmalloc(sizeof(*k));
53 k->type = type;
Damien Millereba71ba2000-04-29 23:57:08 +100054 k->dsa = NULL;
55 k->rsa = NULL;
Damien Miller450a7a12000-03-26 13:04:51 +100056 switch (k->type) {
57 case KEY_RSA:
58 rsa = RSA_new();
59 rsa->n = BN_new();
60 rsa->e = BN_new();
61 k->rsa = rsa;
62 break;
63 case KEY_DSA:
64 dsa = DSA_new();
65 dsa->p = BN_new();
66 dsa->q = BN_new();
67 dsa->g = BN_new();
68 dsa->pub_key = BN_new();
69 k->dsa = dsa;
70 break;
71 case KEY_EMPTY:
Damien Miller450a7a12000-03-26 13:04:51 +100072 break;
73 default:
74 fatal("key_new: bad key type %d", k->type);
75 break;
76 }
77 return k;
78}
79void
80key_free(Key *k)
81{
82 switch (k->type) {
83 case KEY_RSA:
84 if (k->rsa != NULL)
85 RSA_free(k->rsa);
86 k->rsa = NULL;
87 break;
88 case KEY_DSA:
89 if (k->dsa != NULL)
90 DSA_free(k->dsa);
91 k->dsa = NULL;
92 break;
93 default:
94 fatal("key_free: bad key type %d", k->type);
95 break;
96 }
97 xfree(k);
98}
99int
100key_equal(Key *a, Key *b)
101{
102 if (a == NULL || b == NULL || a->type != b->type)
103 return 0;
104 switch (a->type) {
105 case KEY_RSA:
106 return a->rsa != NULL && b->rsa != NULL &&
107 BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
108 BN_cmp(a->rsa->n, b->rsa->n) == 0;
109 break;
110 case KEY_DSA:
111 return a->dsa != NULL && b->dsa != NULL &&
112 BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
113 BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
114 BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
115 BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
116 break;
117 default:
Damien Millereba71ba2000-04-29 23:57:08 +1000118 fatal("key_equal: bad key type %d", a->type);
Damien Miller450a7a12000-03-26 13:04:51 +1000119 break;
120 }
121 return 0;
122}
123
124#define FPRINT "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x"
125
126/*
127 * Generate key fingerprint in ascii format.
128 * Based on ideas and code from Bjoern Groenvall <bg@sics.se>
129 */
130char *
131key_fingerprint(Key *k)
132{
133 static char retval[80];
Damien Millereba71ba2000-04-29 23:57:08 +1000134 unsigned char *blob = NULL;
Damien Miller450a7a12000-03-26 13:04:51 +1000135 int len = 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000136 int nlen, elen;
Damien Miller450a7a12000-03-26 13:04:51 +1000137
138 switch (k->type) {
139 case KEY_RSA:
140 nlen = BN_num_bytes(k->rsa->n);
141 elen = BN_num_bytes(k->rsa->e);
142 len = nlen + elen;
Damien Millereba71ba2000-04-29 23:57:08 +1000143 blob = xmalloc(len);
144 BN_bn2bin(k->rsa->n, blob);
145 BN_bn2bin(k->rsa->e, blob + nlen);
Damien Miller450a7a12000-03-26 13:04:51 +1000146 break;
147 case KEY_DSA:
Damien Millereba71ba2000-04-29 23:57:08 +1000148 dsa_make_key_blob(k, &blob, &len);
Damien Miller450a7a12000-03-26 13:04:51 +1000149 break;
150 default:
151 fatal("key_fingerprint: bad key type %d", k->type);
152 break;
153 }
Damien Millereba71ba2000-04-29 23:57:08 +1000154 if (blob != NULL) {
Damien Miller450a7a12000-03-26 13:04:51 +1000155 unsigned char d[16];
156 EVP_MD_CTX md;
157 EVP_DigestInit(&md, EVP_md5());
Damien Millereba71ba2000-04-29 23:57:08 +1000158 EVP_DigestUpdate(&md, blob, len);
Damien Miller450a7a12000-03-26 13:04:51 +1000159 EVP_DigestFinal(&md, d, NULL);
160 snprintf(retval, sizeof(retval), FPRINT,
161 d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7],
162 d[8], d[9], d[10], d[11], d[12], d[13], d[14], d[15]);
Damien Millereba71ba2000-04-29 23:57:08 +1000163 memset(blob, 0, len);
164 xfree(blob);
Damien Miller450a7a12000-03-26 13:04:51 +1000165 }
166 return retval;
167}
168
169/*
170 * Reads a multiple-precision integer in decimal from the buffer, and advances
171 * the pointer. The integer must already be initialized. This function is
172 * permitted to modify the buffer. This leaves *cpp to point just beyond the
173 * last processed (and maybe modified) character. Note that this may modify
174 * the buffer containing the number.
175 */
176int
177read_bignum(char **cpp, BIGNUM * value)
178{
179 char *cp = *cpp;
180 int old;
181
182 /* Skip any leading whitespace. */
183 for (; *cp == ' ' || *cp == '\t'; cp++)
184 ;
185
186 /* Check that it begins with a decimal digit. */
187 if (*cp < '0' || *cp > '9')
188 return 0;
189
190 /* Save starting position. */
191 *cpp = cp;
192
193 /* Move forward until all decimal digits skipped. */
194 for (; *cp >= '0' && *cp <= '9'; cp++)
195 ;
196
197 /* Save the old terminating character, and replace it by \0. */
198 old = *cp;
199 *cp = 0;
200
201 /* Parse the number. */
202 if (BN_dec2bn(&value, *cpp) == 0)
203 return 0;
204
205 /* Restore old terminating character. */
206 *cp = old;
207
208 /* Move beyond the number and return success. */
209 *cpp = cp;
210 return 1;
211}
212int
213write_bignum(FILE *f, BIGNUM *num)
214{
215 char *buf = BN_bn2dec(num);
216 if (buf == NULL) {
217 error("write_bignum: BN_bn2dec() failed");
218 return 0;
219 }
220 fprintf(f, " %s", buf);
221 free(buf);
222 return 1;
223}
Damien Millereba71ba2000-04-29 23:57:08 +1000224unsigned int
225key_read(Key *ret, char **cpp)
Damien Miller450a7a12000-03-26 13:04:51 +1000226{
Damien Millereba71ba2000-04-29 23:57:08 +1000227 Key *k;
228 unsigned int bits = 0;
229 char *cp;
230 int len, n;
231 unsigned char *blob;
232
233 cp = *cpp;
234
Damien Miller450a7a12000-03-26 13:04:51 +1000235 switch(ret->type) {
236 case KEY_RSA:
Damien Millereba71ba2000-04-29 23:57:08 +1000237 /* Get number of bits. */
238 if (*cp < '0' || *cp > '9')
239 return 0; /* Bad bit count... */
240 for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
241 bits = 10 * bits + *cp - '0';
Damien Miller450a7a12000-03-26 13:04:51 +1000242 if (bits == 0)
243 return 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000244 *cpp = cp;
Damien Miller450a7a12000-03-26 13:04:51 +1000245 /* Get public exponent, public modulus. */
246 if (!read_bignum(cpp, ret->rsa->e))
247 return 0;
248 if (!read_bignum(cpp, ret->rsa->n))
249 return 0;
250 break;
251 case KEY_DSA:
Damien Millereba71ba2000-04-29 23:57:08 +1000252 if (strncmp(cp, SSH_DSS " ", 7) != 0)
Damien Miller450a7a12000-03-26 13:04:51 +1000253 return 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000254 cp += 7;
255 len = 2*strlen(cp);
256 blob = xmalloc(len);
257 n = uudecode(cp, blob, len);
Damien Millere247cc42000-05-07 12:03:14 +1000258 if (n < 0) {
259 error("uudecode %s failed", cp);
260 return 0;
261 }
Damien Millereba71ba2000-04-29 23:57:08 +1000262 k = dsa_key_from_blob(blob, n);
263 if (k == NULL)
264 return 0;
265 xfree(blob);
266 if (ret->dsa != NULL)
267 DSA_free(ret->dsa);
268 ret->dsa = k->dsa;
269 k->dsa = NULL;
270 key_free(k);
271 bits = BN_num_bits(ret->dsa->p);
272 cp = strchr(cp, '=');
273 if (cp == NULL)
Damien Miller450a7a12000-03-26 13:04:51 +1000274 return 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000275 *cpp = cp + 1;
Damien Miller450a7a12000-03-26 13:04:51 +1000276 break;
277 default:
Damien Millereba71ba2000-04-29 23:57:08 +1000278 fatal("key_read: bad key type: %d", ret->type);
Damien Miller450a7a12000-03-26 13:04:51 +1000279 break;
280 }
Damien Millereba71ba2000-04-29 23:57:08 +1000281 return bits;
Damien Miller450a7a12000-03-26 13:04:51 +1000282}
283int
284key_write(Key *key, FILE *f)
285{
286 int success = 0;
287 unsigned int bits = 0;
288
289 if (key->type == KEY_RSA && key->rsa != NULL) {
290 /* size of modulus 'n' */
291 bits = BN_num_bits(key->rsa->n);
292 fprintf(f, "%u", bits);
293 if (write_bignum(f, key->rsa->e) &&
294 write_bignum(f, key->rsa->n)) {
295 success = 1;
296 } else {
297 error("key_write: failed for RSA key");
298 }
299 } else if (key->type == KEY_DSA && key->dsa != NULL) {
Damien Millereba71ba2000-04-29 23:57:08 +1000300 int len, n;
301 unsigned char *blob, *uu;
302 dsa_make_key_blob(key, &blob, &len);
303 uu = xmalloc(2*len);
Damien Millere247cc42000-05-07 12:03:14 +1000304 n = uuencode(blob, len, uu, 2*len);
305 if (n > 0) {
306 fprintf(f, "%s %s", SSH_DSS, uu);
307 success = 1;
308 }
Damien Millereba71ba2000-04-29 23:57:08 +1000309 xfree(blob);
310 xfree(uu);
Damien Miller450a7a12000-03-26 13:04:51 +1000311 }
312 return success;
313}
Damien Millere247cc42000-05-07 12:03:14 +1000314char *
315key_type(Key *k)
316{
317 switch (k->type) {
318 case KEY_RSA:
319 return "RSA";
320 break;
321 case KEY_DSA:
322 return "DSA";
323 break;
324 }
325 return "unknown";
326}