| 1 |
/* Mixmaster version 3 -- (C) 1999 Anonymizer Inc.
|
| 2 |
|
| 3 |
Mixmaster may be redistributed and modified under certain conditions.
|
| 4 |
This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
|
| 5 |
ANY KIND, either express or implied. See the file COPYRIGHT for
|
| 6 |
details.
|
| 7 |
|
| 8 |
Encrypt message for Mixmaster chain
|
| 9 |
$Id: chain2.c,v 1.1 2001/10/31 08:19:53 rabbi Exp $ */
|
| 10 |
|
| 11 |
|
| 12 |
#include "mix3.h"
|
| 13 |
#include <string.h>
|
| 14 |
#include <stdlib.h>
|
| 15 |
#include <time.h>
|
| 16 |
#include <ctype.h>
|
| 17 |
#include <assert.h>
|
| 18 |
|
| 19 |
#ifdef USE_RSA
|
| 20 |
|
| 21 |
#define N(X) (isdigit(X) ? (X)-'0' : 0)
|
| 22 |
|
| 23 |
int mix2_rlist(REMAILER remailer[])
|
| 24 |
{
|
| 25 |
FILE *list;
|
| 26 |
int n, i, listed = 0;
|
| 27 |
|
| 28 |
char line[LINELEN], name[LINELEN], addr[LINELEN], keyid[LINELEN],
|
| 29 |
version[LINELEN], flags[LINELEN];
|
| 30 |
|
| 31 |
list = mix_openfile(TYPE2LIST, "r");
|
| 32 |
if (list == NULL) {
|
| 33 |
list = mix_openfile(PUBRING, "r");
|
| 34 |
if (list == NULL)
|
| 35 |
return (-1);
|
| 36 |
}
|
| 37 |
for (n = 1; fgets(line, sizeof(line), list) != NULL && n < MAXREM;)
|
| 38 |
if (strleft(line, begin_key)) {
|
| 39 |
while (fgets(line, sizeof(line), list) != NULL &&
|
| 40 |
!strleft(line, end_key)) ;
|
| 41 |
} else if (strlen(line) > 36 && line[0] != '#') {
|
| 42 |
flags[0] = '\0';
|
| 43 |
if (sscanf(line, "%127s %127s %127s %127s %127s", name,
|
| 44 |
addr, keyid, version, flags) < 4)
|
| 45 |
continue;
|
| 46 |
strncpy(remailer[n].name, name, sizeof(remailer[n].name));
|
| 47 |
remailer[n].name[sizeof(remailer[n].name) - 1] = '\0';
|
| 48 |
strncpy(remailer[n].addr, addr, sizeof(remailer[n].addr));
|
| 49 |
remailer[n].addr[sizeof(remailer[n].addr) - 1] = '\0';
|
| 50 |
remailer[n].flags.mix = 1;
|
| 51 |
remailer[n].flags.cpunk = 0;
|
| 52 |
remailer[n].flags.nym = 0;
|
| 53 |
remailer[n].flags.newnym = 0;
|
| 54 |
id_decode(keyid, remailer[n].keyid);
|
| 55 |
remailer[n].version = N(version[0]);
|
| 56 |
remailer[n].flags.compress = strfind(flags, "C");
|
| 57 |
remailer[n].flags.post = strfind(flags, "N");
|
| 58 |
remailer[n].flags.middle = strfind(flags, "M");
|
| 59 |
remailer[n].info[0].reliability = 0;
|
| 60 |
remailer[n].info[0].latency = 0;
|
| 61 |
remailer[n].info[0].history[0] = '\0';
|
| 62 |
n++;
|
| 63 |
}
|
| 64 |
fclose(list);
|
| 65 |
list = mix_openfile(TYPE2REL, "r");
|
| 66 |
if (list != NULL) {
|
| 67 |
while (fgets(line, sizeof(line), list) != NULL &&
|
| 68 |
!strleft(line, "--------------------------------------------")) ;
|
| 69 |
while (fgets(line, sizeof(line), list) != NULL &&
|
| 70 |
!strleft(line, "</PRE>"))
|
| 71 |
if (strlen(line) >= 44 && strlen(line) <= 46)
|
| 72 |
for (i = 1; i < n; i++)
|
| 73 |
if (strleft(line, remailer[i].name) &&
|
| 74 |
line[strlen(remailer[i].name)] == ' ') {
|
| 75 |
strncpy(remailer[i].info[0].history, line + 15, 12);
|
| 76 |
remailer[i].info[0].history[12] = '\0';
|
| 77 |
remailer[i].info[0].reliability = 10000 * N(line[37])
|
| 78 |
+ 1000 * N(line[38]) + 100 * N(line[39])
|
| 79 |
+ 10 * N(line[41]) + N(line[42]);
|
| 80 |
remailer[i].info[0].latency = 36000 * N(line[28])
|
| 81 |
+ 3600 * N(line[29]) + 600 * N(line[31])
|
| 82 |
+ 60 * N(line[32]) + 10 * N(line[34])
|
| 83 |
+ N(line[35]);
|
| 84 |
listed++;
|
| 85 |
}
|
| 86 |
fclose(list);
|
| 87 |
}
|
| 88 |
if (listed < 4) /* we have no valid reliability info */
|
| 89 |
for (i = 1; i < n; i++)
|
| 90 |
remailer[i].info[0].reliability = 10000;
|
| 91 |
return (n);
|
| 92 |
}
|
| 93 |
|
| 94 |
static int send_packet(int numcopies, BUFFER *packet, int chain[],
|
| 95 |
int chainlen, int packetnum, int numpackets,
|
| 96 |
BUFFER *mid, REMAILER remailer[], int maxrem,
|
| 97 |
BUFFER *feedback)
|
| 98 |
{
|
| 99 |
BUFFER *pid, *out, *header, *other, *encrypted, *key, *body;
|
| 100 |
BUFFER *iv, *ivarray, *temp;
|
| 101 |
BUFFER *pubkey;
|
| 102 |
char addr[LINELEN];
|
| 103 |
int thischain[20];
|
| 104 |
int hop;
|
| 105 |
int c, i;
|
| 106 |
int timestamp = 0;
|
| 107 |
int israndom = 0;
|
| 108 |
int err = 1;
|
| 109 |
|
| 110 |
body = buf_new();
|
| 111 |
pid = buf_new();
|
| 112 |
out = buf_new();
|
| 113 |
header = buf_new();
|
| 114 |
other = buf_new();
|
| 115 |
key = buf_new();
|
| 116 |
encrypted = buf_new();
|
| 117 |
iv = buf_new();
|
| 118 |
ivarray = buf_new();
|
| 119 |
temp = buf_new();
|
| 120 |
|
| 121 |
buf_setrnd(pid, 16);
|
| 122 |
|
| 123 |
for (c = 0; c < numcopies; c++) {
|
| 124 |
buf_set(body, packet);
|
| 125 |
|
| 126 |
for (hop = 0; hop < chainlen; hop++)
|
| 127 |
thischain[hop] = chain[hop];
|
| 128 |
|
| 129 |
israndom = chain_rand(remailer, maxrem, thischain, chainlen, 0);
|
| 130 |
if (israndom == -1) {
|
| 131 |
err = -1;
|
| 132 |
clienterr(feedback, "No reliable remailers!");
|
| 133 |
}
|
| 134 |
if ((numcopies > 1 || numpackets > 1) && !israndom && (chainlen != 1)) {
|
| 135 |
clienterr(feedback,
|
| 136 |
"Multi-packet message without random remailers!");
|
| 137 |
err = -1;
|
| 138 |
goto end;
|
| 139 |
}
|
| 140 |
for (hop = 0; hop < chainlen; hop++) {
|
| 141 |
switch (remailer[thischain[hop]].version) {
|
| 142 |
case 2:
|
| 143 |
case 3: /* not implemented yet; fall back to version 2 */
|
| 144 |
/* create header chart to be encrypted with the session key */
|
| 145 |
if (numcopies > 1 && hop == 0)
|
| 146 |
buf_set(encrypted, pid); /* same ID only at final hop */
|
| 147 |
else
|
| 148 |
buf_setrnd(encrypted, 16);
|
| 149 |
buf_setrnd(key, 24); /* key for encrypting the body */
|
| 150 |
buf_cat(encrypted, key);
|
| 151 |
buf_setrnd(iv, 8); /* IV for encrypting the body */
|
| 152 |
|
| 153 |
if (hop > 0) {
|
| 154 |
/* IVs for header chart encryption */
|
| 155 |
buf_setrnd(ivarray, 18 * 8);
|
| 156 |
buf_cat(ivarray, iv); /* 19th IV equals the body IV */
|
| 157 |
|
| 158 |
buf_appendc(encrypted, 0);
|
| 159 |
buf_cat(encrypted, ivarray);
|
| 160 |
memset(addr, 0, 80);
|
| 161 |
strcpy(addr, remailer[thischain[hop - 1]].addr);
|
| 162 |
buf_append(encrypted, addr, 80);
|
| 163 |
} else {
|
| 164 |
if (numpackets == 1)
|
| 165 |
buf_appendc(encrypted, 1);
|
| 166 |
else {
|
| 167 |
buf_appendc(encrypted, 2);
|
| 168 |
buf_appendc(encrypted, (byte) packetnum);
|
| 169 |
buf_appendc(encrypted, (byte) numpackets);
|
| 170 |
}
|
| 171 |
buf_cat(encrypted, mid);
|
| 172 |
buf_cat(encrypted, iv); /* body encryption IV */
|
| 173 |
}
|
| 174 |
|
| 175 |
/* timestamp */
|
| 176 |
buf_appends(encrypted, "0000");
|
| 177 |
buf_appendc(encrypted, '\0'); /* timestamp magic */
|
| 178 |
timestamp = time(NULL) / SECONDSPERDAY - rnd_number(4);
|
| 179 |
buf_appendi_lo(encrypted, timestamp);
|
| 180 |
|
| 181 |
/* message digest for this header */
|
| 182 |
digest_md5(encrypted, temp);
|
| 183 |
buf_cat(encrypted, temp);
|
| 184 |
buf_pad(encrypted, 328);
|
| 185 |
|
| 186 |
/* encrypt message body */
|
| 187 |
buf_crypt(body, key, iv, ENCRYPT);
|
| 188 |
|
| 189 |
if (hop > 0) {
|
| 190 |
/* encrypt the other header charts */
|
| 191 |
buf_clear(other);
|
| 192 |
for (i = 0; i < 19; i++) {
|
| 193 |
buf_clear(iv);
|
| 194 |
buf_clear(temp);
|
| 195 |
buf_append(iv, ivarray->data + 8 * i, 8);
|
| 196 |
buf_append(temp, header->data + 512 * i, 512);
|
| 197 |
buf_crypt(temp, key, iv, ENCRYPT);
|
| 198 |
buf_cat(other, temp);
|
| 199 |
}
|
| 200 |
} else
|
| 201 |
buf_setrnd(other, 19 * 512); /* fill with random data */
|
| 202 |
|
| 203 |
/* create session key and IV to encrypt the header ... */
|
| 204 |
buf_setrnd(key, 24);
|
| 205 |
buf_setrnd(iv, 8);
|
| 206 |
buf_crypt(encrypted, key, iv, ENCRYPT);
|
| 207 |
pubkey = buf_new();
|
| 208 |
err = db_getpubkey(remailer[thischain[hop]].keyid, pubkey);
|
| 209 |
if (err == -1)
|
| 210 |
goto end;
|
| 211 |
err = pk_encrypt(key, pubkey); /* ... and encrypt the
|
| 212 |
session key */
|
| 213 |
buf_free(pubkey);
|
| 214 |
if (err == -1 || key->length != 128) {
|
| 215 |
clienterr(feedback, "Encryption failed!");
|
| 216 |
err = -1;
|
| 217 |
goto end;
|
| 218 |
}
|
| 219 |
/* now build the new header */
|
| 220 |
buf_clear(header);
|
| 221 |
buf_append(header, remailer[thischain[hop]].keyid, 16);
|
| 222 |
buf_appendc(header, 128);
|
| 223 |
buf_cat(header, key);
|
| 224 |
buf_cat(header, iv);
|
| 225 |
buf_cat(header, encrypted);
|
| 226 |
buf_pad(header, 512);
|
| 227 |
buf_cat(header, other);
|
| 228 |
break;
|
| 229 |
default:
|
| 230 |
err = -1;
|
| 231 |
goto end;
|
| 232 |
}
|
| 233 |
}
|
| 234 |
|
| 235 |
/* build the message */
|
| 236 |
buf_sets(out, remailer[thischain[chainlen - 1]].addr);
|
| 237 |
buf_nl(out);
|
| 238 |
buf_cat(out, header);
|
| 239 |
buf_cat(out, body);
|
| 240 |
assert(header->length == 10240 && body->length == 10240);
|
| 241 |
mix_pool(out, INTERMEDIATE, -1);
|
| 242 |
|
| 243 |
if (feedback) {
|
| 244 |
for (hop = chainlen - 1; hop >= 0; hop--) {
|
| 245 |
buf_appends(feedback, remailer[thischain[hop]].name);
|
| 246 |
if (hop > 0)
|
| 247 |
buf_appendc(feedback, ',');
|
| 248 |
}
|
| 249 |
buf_nl(feedback);
|
| 250 |
}
|
| 251 |
}
|
| 252 |
end:
|
| 253 |
buf_free(pid);
|
| 254 |
buf_free(body);
|
| 255 |
buf_free(out);
|
| 256 |
buf_free(header);
|
| 257 |
buf_free(temp);
|
| 258 |
buf_free(other);
|
| 259 |
buf_free(key);
|
| 260 |
buf_free(encrypted);
|
| 261 |
buf_free(iv);
|
| 262 |
buf_free(ivarray);
|
| 263 |
return (err);
|
| 264 |
}
|
| 265 |
|
| 266 |
int mix2_encrypt(int type, BUFFER *message, char *chainstr, int numcopies,
|
| 267 |
BUFFER *feedback)
|
| 268 |
{
|
| 269 |
/* returns 0 on success, -1 on error. feedback contains the selected
|
| 270 |
remailer chain or an error message */
|
| 271 |
|
| 272 |
REMAILER remailer[MAXREM];
|
| 273 |
int maxrem;
|
| 274 |
BUFFER *line, *field, *content, *header, *msgdest, *msgheader, *body,
|
| 275 |
*temp, *mid;
|
| 276 |
byte numdest = 0, numhdr = 0;
|
| 277 |
char hdrline[LINELEN];
|
| 278 |
BUFFER *packet;
|
| 279 |
int chain[20];
|
| 280 |
int chainlen;
|
| 281 |
int i;
|
| 282 |
int err = 0;
|
| 283 |
|
| 284 |
mix_init(NULL);
|
| 285 |
packet = buf_new();
|
| 286 |
line = buf_new();
|
| 287 |
field = buf_new();
|
| 288 |
content = buf_new();
|
| 289 |
msgheader = buf_new();
|
| 290 |
msgdest = buf_new();
|
| 291 |
body = buf_new();
|
| 292 |
temp = buf_new();
|
| 293 |
mid = buf_new();
|
| 294 |
header = buf_new();
|
| 295 |
if (feedback)
|
| 296 |
buf_reset(feedback);
|
| 297 |
|
| 298 |
if (numcopies == 0)
|
| 299 |
numcopies = NUMCOPIES;
|
| 300 |
if (numcopies > 10)
|
| 301 |
numcopies = 10;
|
| 302 |
|
| 303 |
maxrem = mix2_rlist(remailer);
|
| 304 |
if (maxrem < 1) {
|
| 305 |
clienterr(feedback, "No remailer list!");
|
| 306 |
err = -1;
|
| 307 |
goto end;
|
| 308 |
}
|
| 309 |
chainlen = chain_select(chain, chainstr, maxrem, remailer, 0, line);
|
| 310 |
if (chainlen < 1) {
|
| 311 |
if (line->length)
|
| 312 |
clienterr(feedback, line->data);
|
| 313 |
else
|
| 314 |
clienterr(feedback, "Invalid remailer chain!");
|
| 315 |
err = -1;
|
| 316 |
goto end;
|
| 317 |
}
|
| 318 |
if (chain[0] == 0)
|
| 319 |
chain[0] = chain_randfinal(type, remailer, maxrem, 0);
|
| 320 |
|
| 321 |
if (chain[0] == -1) {
|
| 322 |
clienterr(feedback, "No reliable remailers!");
|
| 323 |
err = -1;
|
| 324 |
goto end;
|
| 325 |
}
|
| 326 |
switch (remailer[chain[0]].version) {
|
| 327 |
case 2:
|
| 328 |
if (type == MSG_NULL) {
|
| 329 |
memset(hdrline, 0, 80);
|
| 330 |
strcpy(hdrline, "null:");
|
| 331 |
buf_append(msgdest, hdrline, 80);
|
| 332 |
numdest++;
|
| 333 |
} else
|
| 334 |
while (buf_getheader(message, field, content) == 0) {
|
| 335 |
if (bufieq(field, "to")) {
|
| 336 |
memset(hdrline, 0, 80);
|
| 337 |
strncpy(hdrline, content->data, 80);
|
| 338 |
buf_append(msgdest, hdrline, 80);
|
| 339 |
numdest++;
|
| 340 |
} else if (type == MSG_POST && bufieq(field, "newsgroups")) {
|
| 341 |
memset(hdrline, 0, 80);
|
| 342 |
strcpy(hdrline, "post: ");
|
| 343 |
strcatn(hdrline, content->data, 80);
|
| 344 |
buf_append(msgdest, hdrline, 80);
|
| 345 |
numdest++;
|
| 346 |
} else {
|
| 347 |
buf_clear(header);
|
| 348 |
buf_appendheader(header, field, content);
|
| 349 |
hdr_encode(header, 80);
|
| 350 |
while (buf_getline(header, line) == 0) {
|
| 351 |
/* paste in encoded header entry */
|
| 352 |
memset(hdrline, 0, 80);
|
| 353 |
strncpy(hdrline, line->data, 80);
|
| 354 |
buf_append(msgheader, hdrline, 80);
|
| 355 |
numhdr++;
|
| 356 |
}
|
| 357 |
}
|
| 358 |
}
|
| 359 |
buf_appendc(body, numdest);
|
| 360 |
buf_cat(body, msgdest);
|
| 361 |
buf_appendc(body, numhdr);
|
| 362 |
buf_cat(body, msgheader);
|
| 363 |
|
| 364 |
if (type != MSG_NULL) {
|
| 365 |
buf_rest(temp, message);
|
| 366 |
if (temp->length > 10236 && remailer[chain[0]].flags.compress)
|
| 367 |
buf_compress(temp);
|
| 368 |
buf_cat(body, temp);
|
| 369 |
buf_reset(temp);
|
| 370 |
}
|
| 371 |
buf_setrnd(mid, 16); /* message ID */
|
| 372 |
for (i = 0; i <= body->length / 10236; i++) {
|
| 373 |
long length;
|
| 374 |
|
| 375 |
length = body->length - i * 10236;
|
| 376 |
if (length > 10236)
|
| 377 |
length = 10236;
|
| 378 |
buf_clear(packet);
|
| 379 |
buf_appendl_lo(packet, length);
|
| 380 |
buf_append(packet, body->data + i * 10236, length);
|
| 381 |
buf_pad(packet, 10240);
|
| 382 |
if (send_packet(numcopies, packet, chain, chainlen,
|
| 383 |
i + 1, body->length / 10236 + 1,
|
| 384 |
mid, remailer, maxrem, feedback) == -1)
|
| 385 |
err = -1;
|
| 386 |
}
|
| 387 |
break;
|
| 388 |
case 3:
|
| 389 |
NOT_IMPLEMENTED;
|
| 390 |
break;
|
| 391 |
default:
|
| 392 |
clienterr(feedback, "Unknown remailer version!");
|
| 393 |
err = -1;
|
| 394 |
}
|
| 395 |
|
| 396 |
end:
|
| 397 |
buf_free(packet);
|
| 398 |
buf_free(line);
|
| 399 |
buf_free(field);
|
| 400 |
buf_free(content);
|
| 401 |
buf_free(header);
|
| 402 |
buf_free(msgheader);
|
| 403 |
buf_free(msgdest);
|
| 404 |
buf_free(body);
|
| 405 |
buf_free(temp);
|
| 406 |
buf_free(mid);
|
| 407 |
return (err);
|
| 408 |
}
|
| 409 |
|
| 410 |
#else
|
| 411 |
|
| 412 |
int mix2_rlist(REMAILER remailer[])
|
| 413 |
{
|
| 414 |
return (0);
|
| 415 |
}
|
| 416 |
|
| 417 |
int mix2_encrypt(int type, BUFFER *message, char *chainstr, int numcopies,
|
| 418 |
BUFFER *feedback)
|
| 419 |
{
|
| 420 |
return (-1);
|
| 421 |
}
|
| 422 |
#endif
|
Parent Directory
| 
Revision Log