17
18#include "ssh.h"
19#include "cipher.h"
20#include "xmalloc.h"
21
22#include <openssl/md5.h>
23
24/*
25 * This is used by SSH1:
26 *
27 * What kind of triple DES are these 2 routines?
28 *
29 * Why is there a redundant initialization vector?
30 *
31 * If only iv3 was used, then, this would till effect have been
32 * outer-cbc. However, there is also a private iv1 == iv2 which
33 * perhaps makes differential analysis easier. On the other hand, the
34 * private iv1 probably makes the CRC-32 attack ineffective. This is a
35 * result of that there is no longer any known iv1 to use when
36 * choosing the X block.
37 */
38void
39SSH_3CBC_ENCRYPT(des_key_schedule ks1,
40 des_key_schedule ks2, des_cblock * iv2,
41 des_key_schedule ks3, des_cblock * iv3,
42 unsigned char *dest, unsigned char *src,
43 unsigned int len)
44{
45 des_cblock iv1;
46
47 memcpy(&iv1, iv2, 8);
48
49 des_cbc_encrypt(src, dest, len, ks1, &iv1, DES_ENCRYPT);
50 memcpy(&iv1, dest + len - 8, 8);
51
52 des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_DECRYPT);
53 memcpy(iv2, &iv1, 8); /* Note how iv1 == iv2 on entry and exit. */
54
55 des_cbc_encrypt(dest, dest, len, ks3, iv3, DES_ENCRYPT);
56 memcpy(iv3, dest + len - 8, 8);
57}
58
59void
60SSH_3CBC_DECRYPT(des_key_schedule ks1,
61 des_key_schedule ks2, des_cblock * iv2,
62 des_key_schedule ks3, des_cblock * iv3,
63 unsigned char *dest, unsigned char *src,
64 unsigned int len)
65{
66 des_cblock iv1;
67
68 memcpy(&iv1, iv2, 8);
69
70 des_cbc_encrypt(src, dest, len, ks3, iv3, DES_DECRYPT);
71 memcpy(iv3, src + len - 8, 8);
72
73 des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_ENCRYPT);
74 memcpy(iv2, dest + len - 8, 8);
75
76 des_cbc_encrypt(dest, dest, len, ks1, &iv1, DES_DECRYPT);
77 /* memcpy(&iv1, iv2, 8); */
78 /* Note how iv1 == iv2 on entry and exit. */
79}
80
81/*
82 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
83 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
84 */
85static void
86swap_bytes(const unsigned char *src, unsigned char *dst_, int n)
87{
88 /* dst must be properly aligned. */
89 u_int32_t *dst = (u_int32_t *) dst_;
90 union {
91 u_int32_t i;
92 char c[4];
93 } t;
94
95 /* Process 8 bytes every lap. */
96 for (n = n / 8; n > 0; n--) {
97 t.c[3] = *src++;
98 t.c[2] = *src++;
99 t.c[1] = *src++;
100 t.c[0] = *src++;
101 *dst++ = t.i;
102
103 t.c[3] = *src++;
104 t.c[2] = *src++;
105 t.c[1] = *src++;
106 t.c[0] = *src++;
107 *dst++ = t.i;
108 }
109}
110
111/*
112 * Names of all encryption algorithms.
113 * These must match the numbers defined in cipher.h.
114 */
115static char *cipher_names[] =
116{
117 "none",
118 "idea",
119 "des",
120 "3des",
121 "tss",
122 "rc4",
123 "blowfish",
124 "reserved",
125 "blowfish-cbc",
126 "3des-cbc",
127 "arcfour",
128 "cast128-cbc"
129};
130
131/*
132 * Returns a bit mask indicating which ciphers are supported by this
133 * implementation. The bit mask has the corresponding bit set of each
134 * supported cipher.
135 */
136
137unsigned int
138cipher_mask1()
139{
140 unsigned int mask = 0;
141 mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */
142 mask |= 1 << SSH_CIPHER_BLOWFISH;
143 return mask;
144}
145unsigned int
146cipher_mask2()
147{
148 unsigned int mask = 0;
149 mask |= 1 << SSH_CIPHER_BLOWFISH_CBC;
150 mask |= 1 << SSH_CIPHER_3DES_CBC;
151 mask |= 1 << SSH_CIPHER_ARCFOUR;
152 mask |= 1 << SSH_CIPHER_CAST128_CBC;
153 return mask;
154}
155unsigned int
156cipher_mask()
157{
158 return cipher_mask1() | cipher_mask2();
159}
160
161/* Returns the name of the cipher. */
162
163const char *
164cipher_name(int cipher)
165{
166 if (cipher < 0 || cipher >= sizeof(cipher_names) / sizeof(cipher_names[0]) ||
167 cipher_names[cipher] == NULL)
168 fatal("cipher_name: bad cipher name: %d", cipher);
169 return cipher_names[cipher];
170}
171
172/* Returns 1 if the name of the ciphers are valid. */
173
174#define CIPHER_SEP ","
175int
176ciphers_valid(const char *names)
177{
178 char *ciphers;
179 char *p;
180 int i;
181
| 17
18#include "ssh.h"
19#include "cipher.h"
20#include "xmalloc.h"
21
22#include <openssl/md5.h>
23
24/*
25 * This is used by SSH1:
26 *
27 * What kind of triple DES are these 2 routines?
28 *
29 * Why is there a redundant initialization vector?
30 *
31 * If only iv3 was used, then, this would till effect have been
32 * outer-cbc. However, there is also a private iv1 == iv2 which
33 * perhaps makes differential analysis easier. On the other hand, the
34 * private iv1 probably makes the CRC-32 attack ineffective. This is a
35 * result of that there is no longer any known iv1 to use when
36 * choosing the X block.
37 */
38void
39SSH_3CBC_ENCRYPT(des_key_schedule ks1,
40 des_key_schedule ks2, des_cblock * iv2,
41 des_key_schedule ks3, des_cblock * iv3,
42 unsigned char *dest, unsigned char *src,
43 unsigned int len)
44{
45 des_cblock iv1;
46
47 memcpy(&iv1, iv2, 8);
48
49 des_cbc_encrypt(src, dest, len, ks1, &iv1, DES_ENCRYPT);
50 memcpy(&iv1, dest + len - 8, 8);
51
52 des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_DECRYPT);
53 memcpy(iv2, &iv1, 8); /* Note how iv1 == iv2 on entry and exit. */
54
55 des_cbc_encrypt(dest, dest, len, ks3, iv3, DES_ENCRYPT);
56 memcpy(iv3, dest + len - 8, 8);
57}
58
59void
60SSH_3CBC_DECRYPT(des_key_schedule ks1,
61 des_key_schedule ks2, des_cblock * iv2,
62 des_key_schedule ks3, des_cblock * iv3,
63 unsigned char *dest, unsigned char *src,
64 unsigned int len)
65{
66 des_cblock iv1;
67
68 memcpy(&iv1, iv2, 8);
69
70 des_cbc_encrypt(src, dest, len, ks3, iv3, DES_DECRYPT);
71 memcpy(iv3, src + len - 8, 8);
72
73 des_cbc_encrypt(dest, dest, len, ks2, iv2, DES_ENCRYPT);
74 memcpy(iv2, dest + len - 8, 8);
75
76 des_cbc_encrypt(dest, dest, len, ks1, &iv1, DES_DECRYPT);
77 /* memcpy(&iv1, iv2, 8); */
78 /* Note how iv1 == iv2 on entry and exit. */
79}
80
81/*
82 * SSH1 uses a variation on Blowfish, all bytes must be swapped before
83 * and after encryption/decryption. Thus the swap_bytes stuff (yuk).
84 */
85static void
86swap_bytes(const unsigned char *src, unsigned char *dst_, int n)
87{
88 /* dst must be properly aligned. */
89 u_int32_t *dst = (u_int32_t *) dst_;
90 union {
91 u_int32_t i;
92 char c[4];
93 } t;
94
95 /* Process 8 bytes every lap. */
96 for (n = n / 8; n > 0; n--) {
97 t.c[3] = *src++;
98 t.c[2] = *src++;
99 t.c[1] = *src++;
100 t.c[0] = *src++;
101 *dst++ = t.i;
102
103 t.c[3] = *src++;
104 t.c[2] = *src++;
105 t.c[1] = *src++;
106 t.c[0] = *src++;
107 *dst++ = t.i;
108 }
109}
110
111/*
112 * Names of all encryption algorithms.
113 * These must match the numbers defined in cipher.h.
114 */
115static char *cipher_names[] =
116{
117 "none",
118 "idea",
119 "des",
120 "3des",
121 "tss",
122 "rc4",
123 "blowfish",
124 "reserved",
125 "blowfish-cbc",
126 "3des-cbc",
127 "arcfour",
128 "cast128-cbc"
129};
130
131/*
132 * Returns a bit mask indicating which ciphers are supported by this
133 * implementation. The bit mask has the corresponding bit set of each
134 * supported cipher.
135 */
136
137unsigned int
138cipher_mask1()
139{
140 unsigned int mask = 0;
141 mask |= 1 << SSH_CIPHER_3DES; /* Mandatory */
142 mask |= 1 << SSH_CIPHER_BLOWFISH;
143 return mask;
144}
145unsigned int
146cipher_mask2()
147{
148 unsigned int mask = 0;
149 mask |= 1 << SSH_CIPHER_BLOWFISH_CBC;
150 mask |= 1 << SSH_CIPHER_3DES_CBC;
151 mask |= 1 << SSH_CIPHER_ARCFOUR;
152 mask |= 1 << SSH_CIPHER_CAST128_CBC;
153 return mask;
154}
155unsigned int
156cipher_mask()
157{
158 return cipher_mask1() | cipher_mask2();
159}
160
161/* Returns the name of the cipher. */
162
163const char *
164cipher_name(int cipher)
165{
166 if (cipher < 0 || cipher >= sizeof(cipher_names) / sizeof(cipher_names[0]) ||
167 cipher_names[cipher] == NULL)
168 fatal("cipher_name: bad cipher name: %d", cipher);
169 return cipher_names[cipher];
170}
171
172/* Returns 1 if the name of the ciphers are valid. */
173
174#define CIPHER_SEP ","
175int
176ciphers_valid(const char *names)
177{
178 char *ciphers;
179 char *p;
180 int i;
181
|
205 for (i = 0; i < sizeof(cipher_names) / sizeof(cipher_names[0]); i++)
206 if (strcmp(cipher_names[i], name) == 0 &&
207 (cipher_mask() & (1 << i)))
208 return i;
209 return -1;
210}
211
212/*
213 * Selects the cipher, and keys if by computing the MD5 checksum of the
214 * passphrase and using the resulting 16 bytes as the key.
215 */
216
217void
218cipher_set_key_string(CipherContext *context, int cipher, const char *passphrase)
219{
220 MD5_CTX md;
221 unsigned char digest[16];
222
223 MD5_Init(&md);
224 MD5_Update(&md, (const unsigned char *) passphrase, strlen(passphrase));
225 MD5_Final(digest, &md);
226
227 cipher_set_key(context, cipher, digest, 16);
228
229 memset(digest, 0, sizeof(digest));
230 memset(&md, 0, sizeof(md));
231}
232
233/* Selects the cipher to use and sets the key. */
234
235void
236cipher_set_key(CipherContext *context, int cipher, const unsigned char *key,
237 int keylen)
238{
239 unsigned char padded[32];
240
241 /* Set cipher type. */
242 context->type = cipher;
243
244 /* Get 32 bytes of key data. Pad if necessary. (So that code
245 below does not need to worry about key size). */
246 memset(padded, 0, sizeof(padded));
247 memcpy(padded, key, keylen < sizeof(padded) ? keylen : sizeof(padded));
248
249 /* Initialize the initialization vector. */
250 switch (cipher) {
251 case SSH_CIPHER_NONE:
252 /*
253 * Has to stay for authfile saving of private key with no
254 * passphrase
255 */
256 break;
257
258 case SSH_CIPHER_3DES:
259 /*
260 * Note: the least significant bit of each byte of key is
261 * parity, and must be ignored by the implementation. 16
262 * bytes of key are used (first and last keys are the same).
263 */
264 if (keylen < 16)
265 error("Key length %d is insufficient for 3DES.", keylen);
266 des_set_key((void *) padded, context->u.des3.key1);
267 des_set_key((void *) (padded + 8), context->u.des3.key2);
268 if (keylen <= 16)
269 des_set_key((void *) padded, context->u.des3.key3);
270 else
271 des_set_key((void *) (padded + 16), context->u.des3.key3);
272 memset(context->u.des3.iv2, 0, sizeof(context->u.des3.iv2));
273 memset(context->u.des3.iv3, 0, sizeof(context->u.des3.iv3));
274 break;
275
276 case SSH_CIPHER_BLOWFISH:
277 if (keylen < 16)
278 error("Key length %d is insufficient for blowfish.", keylen);
279 BF_set_key(&context->u.bf.key, keylen, padded);
280 memset(context->u.bf.iv, 0, 8);
281 break;
282
283 case SSH_CIPHER_3DES_CBC:
284 case SSH_CIPHER_BLOWFISH_CBC:
285 case SSH_CIPHER_ARCFOUR:
286 case SSH_CIPHER_CAST128_CBC:
287 fatal("cipher_set_key: illegal cipher: %s", cipher_name(cipher));
288 break;
289
290 default:
291 fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher));
292 }
293 memset(padded, 0, sizeof(padded));
294}
295
296void
297cipher_set_key_iv(CipherContext * context, int cipher,
298 const unsigned char *key, int keylen,
299 const unsigned char *iv, int ivlen)
300{
301 /* Set cipher type. */
302 context->type = cipher;
303
304 /* Initialize the initialization vector. */
305 switch (cipher) {
306 case SSH_CIPHER_NONE:
307 break;
308
309 case SSH_CIPHER_3DES:
310 case SSH_CIPHER_BLOWFISH:
311 fatal("cipher_set_key_iv: illegal cipher: %s", cipher_name(cipher));
312 break;
313
314 case SSH_CIPHER_3DES_CBC:
315 if (keylen < 24)
316 error("Key length %d is insufficient for 3des-cbc.", keylen);
317 des_set_key((void *) key, context->u.des3.key1);
318 des_set_key((void *) (key+8), context->u.des3.key2);
319 des_set_key((void *) (key+16), context->u.des3.key3);
320 if (ivlen < 8)
321 error("IV length %d is insufficient for 3des-cbc.", ivlen);
322 memcpy(context->u.des3.iv3, (char *)iv, 8);
323 break;
324
325 case SSH_CIPHER_BLOWFISH_CBC:
326 if (keylen < 16)
327 error("Key length %d is insufficient for blowfish.", keylen);
328 if (ivlen < 8)
329 error("IV length %d is insufficient for blowfish.", ivlen);
330 BF_set_key(&context->u.bf.key, keylen, (unsigned char *)key);
331 memcpy(context->u.bf.iv, (char *)iv, 8);
332 break;
333
334 case SSH_CIPHER_ARCFOUR:
335 if (keylen < 16)
336 error("Key length %d is insufficient for arcfour.", keylen);
337 RC4_set_key(&context->u.rc4, keylen, (unsigned char *)key);
338 break;
339
340 case SSH_CIPHER_CAST128_CBC:
341 if (keylen < 16)
342 error("Key length %d is insufficient for cast128.", keylen);
343 if (ivlen < 8)
344 error("IV length %d is insufficient for cast128.", ivlen);
345 CAST_set_key(&context->u.cast.key, keylen, (unsigned char *) key);
346 memcpy(context->u.cast.iv, (char *)iv, 8);
347 break;
348
349 default:
350 fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher));
351 }
352}
353
354/* Encrypts data using the cipher. */
355
356void
357cipher_encrypt(CipherContext *context, unsigned char *dest,
358 const unsigned char *src, unsigned int len)
359{
360 if ((len & 7) != 0)
361 fatal("cipher_encrypt: bad plaintext length %d", len);
362
363 switch (context->type) {
364 case SSH_CIPHER_NONE:
365 memcpy(dest, src, len);
366 break;
367
368 case SSH_CIPHER_3DES:
369 SSH_3CBC_ENCRYPT(context->u.des3.key1,
370 context->u.des3.key2, &context->u.des3.iv2,
371 context->u.des3.key3, &context->u.des3.iv3,
372 dest, (unsigned char *) src, len);
373 break;
374
375 case SSH_CIPHER_BLOWFISH:
376 swap_bytes(src, dest, len);
377 BF_cbc_encrypt(dest, dest, len,
378 &context->u.bf.key, context->u.bf.iv,
379 BF_ENCRYPT);
380 swap_bytes(dest, dest, len);
381 break;
382
383 case SSH_CIPHER_BLOWFISH_CBC:
384 BF_cbc_encrypt((void *)src, dest, len,
385 &context->u.bf.key, context->u.bf.iv,
386 BF_ENCRYPT);
387 break;
388
389 case SSH_CIPHER_3DES_CBC:
390 des_ede3_cbc_encrypt(src, dest, len,
391 context->u.des3.key1, context->u.des3.key2,
392 context->u.des3.key3, &context->u.des3.iv3, DES_ENCRYPT);
393 break;
394
395 case SSH_CIPHER_ARCFOUR:
396 RC4(&context->u.rc4, len, (unsigned char *)src, dest);
397 break;
398
399 case SSH_CIPHER_CAST128_CBC:
400 CAST_cbc_encrypt(src, dest, len,
401 &context->u.cast.key, context->u.cast.iv, CAST_ENCRYPT);
402 break;
403
404 default:
405 fatal("cipher_encrypt: unknown cipher: %s", cipher_name(context->type));
406 }
407}
408
409/* Decrypts data using the cipher. */
410
411void
412cipher_decrypt(CipherContext *context, unsigned char *dest,
413 const unsigned char *src, unsigned int len)
414{
415 if ((len & 7) != 0)
416 fatal("cipher_decrypt: bad ciphertext length %d", len);
417
418 switch (context->type) {
419 case SSH_CIPHER_NONE:
420 memcpy(dest, src, len);
421 break;
422
423 case SSH_CIPHER_3DES:
424 SSH_3CBC_DECRYPT(context->u.des3.key1,
425 context->u.des3.key2, &context->u.des3.iv2,
426 context->u.des3.key3, &context->u.des3.iv3,
427 dest, (unsigned char *) src, len);
428 break;
429
430 case SSH_CIPHER_BLOWFISH:
431 swap_bytes(src, dest, len);
432 BF_cbc_encrypt((void *) dest, dest, len,
433 &context->u.bf.key, context->u.bf.iv,
434 BF_DECRYPT);
435 swap_bytes(dest, dest, len);
436 break;
437
438 case SSH_CIPHER_BLOWFISH_CBC:
439 BF_cbc_encrypt((void *) src, dest, len,
440 &context->u.bf.key, context->u.bf.iv,
441 BF_DECRYPT);
442 break;
443
444 case SSH_CIPHER_3DES_CBC:
445 des_ede3_cbc_encrypt(src, dest, len,
446 context->u.des3.key1, context->u.des3.key2,
447 context->u.des3.key3, &context->u.des3.iv3, DES_DECRYPT);
448 break;
449
450 case SSH_CIPHER_ARCFOUR:
451 RC4(&context->u.rc4, len, (unsigned char *)src, dest);
452 break;
453
454 case SSH_CIPHER_CAST128_CBC:
455 CAST_cbc_encrypt(src, dest, len,
456 &context->u.cast.key, context->u.cast.iv, CAST_DECRYPT);
457 break;
458
459 default:
460 fatal("cipher_decrypt: unknown cipher: %s", cipher_name(context->type));
461 }
462}
| 207 for (i = 0; i < sizeof(cipher_names) / sizeof(cipher_names[0]); i++)
208 if (strcmp(cipher_names[i], name) == 0 &&
209 (cipher_mask() & (1 << i)))
210 return i;
211 return -1;
212}
213
214/*
215 * Selects the cipher, and keys if by computing the MD5 checksum of the
216 * passphrase and using the resulting 16 bytes as the key.
217 */
218
219void
220cipher_set_key_string(CipherContext *context, int cipher, const char *passphrase)
221{
222 MD5_CTX md;
223 unsigned char digest[16];
224
225 MD5_Init(&md);
226 MD5_Update(&md, (const unsigned char *) passphrase, strlen(passphrase));
227 MD5_Final(digest, &md);
228
229 cipher_set_key(context, cipher, digest, 16);
230
231 memset(digest, 0, sizeof(digest));
232 memset(&md, 0, sizeof(md));
233}
234
235/* Selects the cipher to use and sets the key. */
236
237void
238cipher_set_key(CipherContext *context, int cipher, const unsigned char *key,
239 int keylen)
240{
241 unsigned char padded[32];
242
243 /* Set cipher type. */
244 context->type = cipher;
245
246 /* Get 32 bytes of key data. Pad if necessary. (So that code
247 below does not need to worry about key size). */
248 memset(padded, 0, sizeof(padded));
249 memcpy(padded, key, keylen < sizeof(padded) ? keylen : sizeof(padded));
250
251 /* Initialize the initialization vector. */
252 switch (cipher) {
253 case SSH_CIPHER_NONE:
254 /*
255 * Has to stay for authfile saving of private key with no
256 * passphrase
257 */
258 break;
259
260 case SSH_CIPHER_3DES:
261 /*
262 * Note: the least significant bit of each byte of key is
263 * parity, and must be ignored by the implementation. 16
264 * bytes of key are used (first and last keys are the same).
265 */
266 if (keylen < 16)
267 error("Key length %d is insufficient for 3DES.", keylen);
268 des_set_key((void *) padded, context->u.des3.key1);
269 des_set_key((void *) (padded + 8), context->u.des3.key2);
270 if (keylen <= 16)
271 des_set_key((void *) padded, context->u.des3.key3);
272 else
273 des_set_key((void *) (padded + 16), context->u.des3.key3);
274 memset(context->u.des3.iv2, 0, sizeof(context->u.des3.iv2));
275 memset(context->u.des3.iv3, 0, sizeof(context->u.des3.iv3));
276 break;
277
278 case SSH_CIPHER_BLOWFISH:
279 if (keylen < 16)
280 error("Key length %d is insufficient for blowfish.", keylen);
281 BF_set_key(&context->u.bf.key, keylen, padded);
282 memset(context->u.bf.iv, 0, 8);
283 break;
284
285 case SSH_CIPHER_3DES_CBC:
286 case SSH_CIPHER_BLOWFISH_CBC:
287 case SSH_CIPHER_ARCFOUR:
288 case SSH_CIPHER_CAST128_CBC:
289 fatal("cipher_set_key: illegal cipher: %s", cipher_name(cipher));
290 break;
291
292 default:
293 fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher));
294 }
295 memset(padded, 0, sizeof(padded));
296}
297
298void
299cipher_set_key_iv(CipherContext * context, int cipher,
300 const unsigned char *key, int keylen,
301 const unsigned char *iv, int ivlen)
302{
303 /* Set cipher type. */
304 context->type = cipher;
305
306 /* Initialize the initialization vector. */
307 switch (cipher) {
308 case SSH_CIPHER_NONE:
309 break;
310
311 case SSH_CIPHER_3DES:
312 case SSH_CIPHER_BLOWFISH:
313 fatal("cipher_set_key_iv: illegal cipher: %s", cipher_name(cipher));
314 break;
315
316 case SSH_CIPHER_3DES_CBC:
317 if (keylen < 24)
318 error("Key length %d is insufficient for 3des-cbc.", keylen);
319 des_set_key((void *) key, context->u.des3.key1);
320 des_set_key((void *) (key+8), context->u.des3.key2);
321 des_set_key((void *) (key+16), context->u.des3.key3);
322 if (ivlen < 8)
323 error("IV length %d is insufficient for 3des-cbc.", ivlen);
324 memcpy(context->u.des3.iv3, (char *)iv, 8);
325 break;
326
327 case SSH_CIPHER_BLOWFISH_CBC:
328 if (keylen < 16)
329 error("Key length %d is insufficient for blowfish.", keylen);
330 if (ivlen < 8)
331 error("IV length %d is insufficient for blowfish.", ivlen);
332 BF_set_key(&context->u.bf.key, keylen, (unsigned char *)key);
333 memcpy(context->u.bf.iv, (char *)iv, 8);
334 break;
335
336 case SSH_CIPHER_ARCFOUR:
337 if (keylen < 16)
338 error("Key length %d is insufficient for arcfour.", keylen);
339 RC4_set_key(&context->u.rc4, keylen, (unsigned char *)key);
340 break;
341
342 case SSH_CIPHER_CAST128_CBC:
343 if (keylen < 16)
344 error("Key length %d is insufficient for cast128.", keylen);
345 if (ivlen < 8)
346 error("IV length %d is insufficient for cast128.", ivlen);
347 CAST_set_key(&context->u.cast.key, keylen, (unsigned char *) key);
348 memcpy(context->u.cast.iv, (char *)iv, 8);
349 break;
350
351 default:
352 fatal("cipher_set_key: unknown cipher: %s", cipher_name(cipher));
353 }
354}
355
356/* Encrypts data using the cipher. */
357
358void
359cipher_encrypt(CipherContext *context, unsigned char *dest,
360 const unsigned char *src, unsigned int len)
361{
362 if ((len & 7) != 0)
363 fatal("cipher_encrypt: bad plaintext length %d", len);
364
365 switch (context->type) {
366 case SSH_CIPHER_NONE:
367 memcpy(dest, src, len);
368 break;
369
370 case SSH_CIPHER_3DES:
371 SSH_3CBC_ENCRYPT(context->u.des3.key1,
372 context->u.des3.key2, &context->u.des3.iv2,
373 context->u.des3.key3, &context->u.des3.iv3,
374 dest, (unsigned char *) src, len);
375 break;
376
377 case SSH_CIPHER_BLOWFISH:
378 swap_bytes(src, dest, len);
379 BF_cbc_encrypt(dest, dest, len,
380 &context->u.bf.key, context->u.bf.iv,
381 BF_ENCRYPT);
382 swap_bytes(dest, dest, len);
383 break;
384
385 case SSH_CIPHER_BLOWFISH_CBC:
386 BF_cbc_encrypt((void *)src, dest, len,
387 &context->u.bf.key, context->u.bf.iv,
388 BF_ENCRYPT);
389 break;
390
391 case SSH_CIPHER_3DES_CBC:
392 des_ede3_cbc_encrypt(src, dest, len,
393 context->u.des3.key1, context->u.des3.key2,
394 context->u.des3.key3, &context->u.des3.iv3, DES_ENCRYPT);
395 break;
396
397 case SSH_CIPHER_ARCFOUR:
398 RC4(&context->u.rc4, len, (unsigned char *)src, dest);
399 break;
400
401 case SSH_CIPHER_CAST128_CBC:
402 CAST_cbc_encrypt(src, dest, len,
403 &context->u.cast.key, context->u.cast.iv, CAST_ENCRYPT);
404 break;
405
406 default:
407 fatal("cipher_encrypt: unknown cipher: %s", cipher_name(context->type));
408 }
409}
410
411/* Decrypts data using the cipher. */
412
413void
414cipher_decrypt(CipherContext *context, unsigned char *dest,
415 const unsigned char *src, unsigned int len)
416{
417 if ((len & 7) != 0)
418 fatal("cipher_decrypt: bad ciphertext length %d", len);
419
420 switch (context->type) {
421 case SSH_CIPHER_NONE:
422 memcpy(dest, src, len);
423 break;
424
425 case SSH_CIPHER_3DES:
426 SSH_3CBC_DECRYPT(context->u.des3.key1,
427 context->u.des3.key2, &context->u.des3.iv2,
428 context->u.des3.key3, &context->u.des3.iv3,
429 dest, (unsigned char *) src, len);
430 break;
431
432 case SSH_CIPHER_BLOWFISH:
433 swap_bytes(src, dest, len);
434 BF_cbc_encrypt((void *) dest, dest, len,
435 &context->u.bf.key, context->u.bf.iv,
436 BF_DECRYPT);
437 swap_bytes(dest, dest, len);
438 break;
439
440 case SSH_CIPHER_BLOWFISH_CBC:
441 BF_cbc_encrypt((void *) src, dest, len,
442 &context->u.bf.key, context->u.bf.iv,
443 BF_DECRYPT);
444 break;
445
446 case SSH_CIPHER_3DES_CBC:
447 des_ede3_cbc_encrypt(src, dest, len,
448 context->u.des3.key1, context->u.des3.key2,
449 context->u.des3.key3, &context->u.des3.iv3, DES_DECRYPT);
450 break;
451
452 case SSH_CIPHER_ARCFOUR:
453 RC4(&context->u.rc4, len, (unsigned char *)src, dest);
454 break;
455
456 case SSH_CIPHER_CAST128_CBC:
457 CAST_cbc_encrypt(src, dest, len,
458 &context->u.cast.key, context->u.cast.iv, CAST_DECRYPT);
459 break;
460
461 default:
462 fatal("cipher_decrypt: unknown cipher: %s", cipher_name(context->type));
463 }
464}
|