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comparison packet.c @ 502:43bbe17d6ba0

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- Add Counter Mode support
author Matt Johnston <matt@ucc.asn.au>
date Mon, 29 Sep 2008 13:53:31 +0000
parents d58c478bd399
children a3748e54273c
comparison
equal deleted inserted replaced
501:d58c478bd399 502:43bbe17d6ba0
192 } 192 }
193 193
194 /* now we have the first block, need to get packet length, so we decrypt 194 /* now we have the first block, need to get packet length, so we decrypt
195 * the first block (only need first 4 bytes) */ 195 * the first block (only need first 4 bytes) */
196 buf_setpos(ses.readbuf, 0); 196 buf_setpos(ses.readbuf, 0);
197 if (ses.keys->recv_algo_crypt->cipherdesc == NULL) { 197 if (ses.keys->recv_crypt_mode->decrypt(buf_getptr(ses.readbuf, blocksize),
198 /* copy it */ 198 buf_getwriteptr(ses.decryptreadbuf,blocksize),
199 memcpy(buf_getwriteptr(ses.decryptreadbuf, blocksize), 199 blocksize,
200 buf_getptr(ses.readbuf, blocksize), 200 &ses.keys->recv_cipher_state) != CRYPT_OK) {
201 blocksize); 201 dropbear_exit("error decrypting");
202 } else {
203 /* decrypt it */
204 if (cbc_decrypt(buf_getptr(ses.readbuf, blocksize),
205 buf_getwriteptr(ses.decryptreadbuf,blocksize),
206 blocksize,
207 &ses.keys->recv_symmetric_struct) != CRYPT_OK) {
208 dropbear_exit("error decrypting");
209 }
210 } 202 }
211 buf_setlen(ses.decryptreadbuf, blocksize); 203 buf_setlen(ses.decryptreadbuf, blocksize);
212 len = buf_getint(ses.decryptreadbuf) + 4 + macsize; 204 len = buf_getint(ses.decryptreadbuf) + 4 + macsize;
213 205
214 buf_setpos(ses.readbuf, blocksize); 206 buf_setpos(ses.readbuf, blocksize);
244 236
245 buf_resize(ses.decryptreadbuf, ses.readbuf->len - macsize); 237 buf_resize(ses.decryptreadbuf, ses.readbuf->len - macsize);
246 buf_setlen(ses.decryptreadbuf, ses.decryptreadbuf->size); 238 buf_setlen(ses.decryptreadbuf, ses.decryptreadbuf->size);
247 buf_setpos(ses.decryptreadbuf, blocksize); 239 buf_setpos(ses.decryptreadbuf, blocksize);
248 240
249 /* decrypt if encryption is set, memcpy otherwise */ 241 /* decrypt it */
250 if (ses.keys->recv_algo_crypt->cipherdesc == NULL) { 242 while (ses.readbuf->pos < ses.readbuf->len - macsize) {
251 /* copy it */ 243 if (ses.keys->recv_crypt_mode->decrypt(
252 len = ses.readbuf->len - macsize - blocksize; 244 buf_getptr(ses.readbuf, blocksize),
253 memcpy(buf_getwriteptr(ses.decryptreadbuf, len), 245 buf_getwriteptr(ses.decryptreadbuf, blocksize),
254 buf_getptr(ses.readbuf, len), len); 246 blocksize,
255 } else { 247 &ses.keys->recv_cipher_state) != CRYPT_OK) {
256 /* decrypt */ 248 dropbear_exit("error decrypting");
257 while (ses.readbuf->pos < ses.readbuf->len - macsize) { 249 }
258 if (cbc_decrypt(buf_getptr(ses.readbuf, blocksize), 250 buf_incrpos(ses.readbuf, blocksize);
259 buf_getwriteptr(ses.decryptreadbuf, blocksize), 251 buf_incrwritepos(ses.decryptreadbuf, blocksize);
260 blocksize,
261 &ses.keys->recv_symmetric_struct) != CRYPT_OK) {
262 dropbear_exit("error decrypting");
263 }
264 buf_incrpos(ses.readbuf, blocksize);
265 buf_incrwritepos(ses.decryptreadbuf, blocksize);
266 }
267 } 252 }
268 253
269 /* check the hmac */ 254 /* check the hmac */
270 buf_setpos(ses.readbuf, ses.readbuf->len - macsize); 255 buf_setpos(ses.readbuf, ses.readbuf->len - macsize);
271 if (checkmac(ses.readbuf, ses.decryptreadbuf) != DROPBEAR_SUCCESS) { 256 if (checkmac(ses.readbuf, ses.decryptreadbuf) != DROPBEAR_SUCCESS) {
542 buf_setpos(clearwritebuf, 0); 527 buf_setpos(clearwritebuf, 0);
543 /* create a new writebuffer, this is freed when it has been put on the 528 /* create a new writebuffer, this is freed when it has been put on the
544 * wire by writepacket() */ 529 * wire by writepacket() */
545 writebuf = buf_new(clearwritebuf->len + macsize); 530 writebuf = buf_new(clearwritebuf->len + macsize);
546 531
547 if (ses.keys->trans_algo_crypt->cipherdesc == NULL) { 532 /* encrypt it */
548 /* copy it */ 533 while (clearwritebuf->pos < clearwritebuf->len) {
549 memcpy(buf_getwriteptr(writebuf, clearwritebuf->len), 534 if (ses.keys->trans_crypt_mode->encrypt(
550 buf_getptr(clearwritebuf, clearwritebuf->len), 535 buf_getptr(clearwritebuf, blocksize),
551 clearwritebuf->len); 536 buf_getwriteptr(writebuf, blocksize),
552 buf_incrwritepos(writebuf, clearwritebuf->len); 537 blocksize,
553 } else { 538 &ses.keys->trans_cipher_state) != CRYPT_OK) {
554 /* encrypt it */ 539 dropbear_exit("error encrypting");
555 while (clearwritebuf->pos < clearwritebuf->len) { 540 }
556 if (cbc_encrypt(buf_getptr(clearwritebuf, blocksize), 541 buf_incrpos(clearwritebuf, blocksize);
557 buf_getwriteptr(writebuf, blocksize), 542 buf_incrwritepos(writebuf, blocksize);
558 blocksize,
559 &ses.keys->trans_symmetric_struct) != CRYPT_OK) {
560 dropbear_exit("error encrypting");
561 }
562 buf_incrpos(clearwritebuf, blocksize);
563 buf_incrwritepos(writebuf, blocksize);
564 }
565 } 543 }
566 544
567 /* now add a hmac and we're done */ 545 /* now add a hmac and we're done */
568 writemac(writebuf, clearwritebuf); 546 writemac(writebuf, clearwritebuf);
569 547