| 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 |
Process Cypherpunk remailer messages
|
| 9 |
$Id: rem1.c,v 1.7 2002/09/18 23:26:17 rabbi Exp $ */
|
| 10 |
|
| 11 |
|
| 12 |
#include "mix3.h"
|
| 13 |
#include <ctype.h>
|
| 14 |
#include <time.h>
|
| 15 |
#include <string.h>
|
| 16 |
|
| 17 |
static int t1msg(BUFFER *in, int hdr);
|
| 18 |
|
| 19 |
int isline(BUFFER *line, char *text)
|
| 20 |
{
|
| 21 |
int i;
|
| 22 |
|
| 23 |
if (!bufileft(line, text))
|
| 24 |
return (0);
|
| 25 |
|
| 26 |
for (i = strlen(text); i < line->length; i++)
|
| 27 |
if (!isspace(line->data[i]))
|
| 28 |
return(0);
|
| 29 |
return(1);
|
| 30 |
}
|
| 31 |
|
| 32 |
int t1_decrypt(BUFFER *in)
|
| 33 |
{
|
| 34 |
int ret;
|
| 35 |
|
| 36 |
buf_rewind(in);
|
| 37 |
if (TYPE1[0] == '\0')
|
| 38 |
ret = t1msg(in, 1);
|
| 39 |
else {
|
| 40 |
FILE *f;
|
| 41 |
|
| 42 |
f = openpipe(TYPE1);
|
| 43 |
if (f == NULL)
|
| 44 |
return -1;
|
| 45 |
buf_write(in, f);
|
| 46 |
ret = closepipe(f);
|
| 47 |
}
|
| 48 |
if (ret == 0)
|
| 49 |
stats_log(1);
|
| 50 |
return (ret);
|
| 51 |
}
|
| 52 |
|
| 53 |
#ifdef USE_IDEA
|
| 54 |
void t1_esub(BUFFER *esub, BUFFER *subject)
|
| 55 |
{
|
| 56 |
BUFFER *iv, *out;
|
| 57 |
char hex[33];
|
| 58 |
|
| 59 |
iv = buf_new();
|
| 60 |
out = buf_new();
|
| 61 |
|
| 62 |
buf_appendrnd(iv, 8);
|
| 63 |
id_encode(iv->data, hex);
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| 64 |
buf_append(out, hex, 16);
|
| 65 |
|
| 66 |
digest_md5(esub, esub);
|
| 67 |
digest_md5(subject, subject);
|
| 68 |
buf_ideacrypt(subject, esub, iv, ENCRYPT);
|
| 69 |
id_encode(subject->data, hex);
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| 70 |
buf_appends(out, hex);
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| 71 |
buf_move(subject, out);
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| 72 |
buf_free(iv);
|
| 73 |
buf_free(out);
|
| 74 |
}
|
| 75 |
#endif /* USE_IDEA */
|
| 76 |
|
| 77 |
#define N(X) (isdigit(X) ? (X)-'0' : 0)
|
| 78 |
|
| 79 |
static int readnum(BUFFER *b, int f)
|
| 80 |
{
|
| 81 |
int num = 0;
|
| 82 |
|
| 83 |
if (b->length > 0)
|
| 84 |
sscanf(b->data, "%d", &num);
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| 85 |
num *= f;
|
| 86 |
if (strchr(b->data, 'r'))
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| 87 |
num = rnd_number(num) + 1;
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| 88 |
return (num);
|
| 89 |
}
|
| 90 |
|
| 91 |
static int t1msg(BUFFER *in, int hdr)
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| 92 |
/* hdr = 1: mail header, hdr = 2: pasted header, hdr = 0: ignore */
|
| 93 |
{
|
| 94 |
BUFFER *field, *content, *line;
|
| 95 |
BUFFER *cutmarks, *to, *newsgroups, *ek, *ekdes, *ekcast, *esub, *subject;
|
| 96 |
BUFFER *temp, *header, *out;
|
| 97 |
BUFFER *test, *testto, *remixto;
|
| 98 |
int err = 0;
|
| 99 |
int encrypted = 0;
|
| 100 |
int type = -1;
|
| 101 |
int latent = 0;
|
| 102 |
int remix = 0, repgp = 0;
|
| 103 |
int inflate = 0;
|
| 104 |
|
| 105 |
field = buf_new();
|
| 106 |
content = buf_new();
|
| 107 |
line = buf_new();
|
| 108 |
to = buf_new();
|
| 109 |
remixto = buf_new();
|
| 110 |
cutmarks = buf_new();
|
| 111 |
newsgroups = buf_new();
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| 112 |
ek = buf_new();
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| 113 |
ekdes = buf_new();
|
| 114 |
ekcast = buf_new();
|
| 115 |
esub = buf_new();
|
| 116 |
subject = buf_new();
|
| 117 |
temp = buf_new();
|
| 118 |
header = buf_new();
|
| 119 |
out = buf_new();
|
| 120 |
test = buf_new();
|
| 121 |
testto = buf_new();
|
| 122 |
|
| 123 |
if (REMIX == 1)
|
| 124 |
remix = 2;
|
| 125 |
if (!UNENCRYPTED)
|
| 126 |
encrypted = -1;
|
| 127 |
|
| 128 |
header:
|
| 129 |
while (buf_getheader(in, field, content) == 0) {
|
| 130 |
if (header->length == 0 && bufieq(content, ":")) /* HDRMARK */
|
| 131 |
hdr = 2;
|
| 132 |
|
| 133 |
if (bufieq(field, "test-to"))
|
| 134 |
buf_set(testto, content);
|
| 135 |
else if (PGP && bufieq(field, "encrypted"))
|
| 136 |
encrypted = 1;
|
| 137 |
else if (bufieq(field, "remix-to")) {
|
| 138 |
remix = 1; repgp = 0;
|
| 139 |
buf_set(remixto, content);
|
| 140 |
if (type == -1)
|
| 141 |
type = MSG_MAIL;
|
| 142 |
} else if (bufieq(field, "encrypt-to")) {
|
| 143 |
repgp = remix = 1;
|
| 144 |
buf_set(remixto, content);
|
| 145 |
if (type == -1)
|
| 146 |
type = MSG_MAIL;
|
| 147 |
} else if (bufieq(field, "anon-to") ||
|
| 148 |
bufieq(field, "request-remailing-to") ||
|
| 149 |
bufieq(field, "remail-to") ||
|
| 150 |
bufieq(field, "anon-send-to")) {
|
| 151 |
if (bufieq(field, "remail-to"))
|
| 152 |
repgp = remix = 0;
|
| 153 |
if (to->length > 0)
|
| 154 |
buf_appendc(to, ',');
|
| 155 |
buf_cat(to, content);
|
| 156 |
if (type == -1)
|
| 157 |
type = MSG_MAIL;
|
| 158 |
} else if (bufieq(field, "anon-post-to") || bufieq(field, "post-to")) {
|
| 159 |
if (newsgroups->length > 0)
|
| 160 |
buf_appendc(newsgroups, ',');
|
| 161 |
buf_cat(newsgroups, content);
|
| 162 |
type = MSG_POST;
|
| 163 |
} else if (bufieq(field, "cutmarks"))
|
| 164 |
buf_set(cutmarks, content);
|
| 165 |
else if (bufieq(field, "latent-time")) {
|
| 166 |
byte *q;
|
| 167 |
int l;
|
| 168 |
|
| 169 |
q = content->data;
|
| 170 |
l = strlen(q);
|
| 171 |
latent = 0;
|
| 172 |
if (q[0] == '+')
|
| 173 |
q++;
|
| 174 |
if (l >= 5 && q[2] == ':')
|
| 175 |
latent = 600 * N(q[0]) + 60 * N(q[1]) + 10 * N(q[3]) + N(q[4]);
|
| 176 |
else if (l >= 4 && q[1] == ':')
|
| 177 |
latent = 60 * N(q[0]) + 10 * N(q[2]) + N(q[3]);
|
| 178 |
else if (l >= 3 && q[0] == ':')
|
| 179 |
latent = 10 * N(q[1]) + N(q[2]);
|
| 180 |
if (!bufleft(content, "+")) {
|
| 181 |
time_t now;
|
| 182 |
|
| 183 |
time(&now);
|
| 184 |
latent -= localtime(&now)->tm_hour * 60;
|
| 185 |
if (latent < 0)
|
| 186 |
latent += 24 * 60;
|
| 187 |
}
|
| 188 |
if (q[l - 1] == 'r')
|
| 189 |
latent = rnd_number(latent);
|
| 190 |
} else if (bufieq(field, "null"))
|
| 191 |
type = MSG_NULL;
|
| 192 |
else if (bufieq(field, "encrypt-key") || bufieq(field, "encrypt-idea"))
|
| 193 |
buf_set(ek, content);
|
| 194 |
else if (bufieq(field, "encrypt-des") || bufieq(field, "encrypt-3des"))
|
| 195 |
buf_set(ekdes, content);
|
| 196 |
else if (bufieq(field, "encrypt-cast") || bufieq(field, "encrypt-cast5"))
|
| 197 |
buf_set(ekcast, content);
|
| 198 |
else if (bufieq(field, "encrypt-subject"))
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| 199 |
buf_set(esub, content);
|
| 200 |
else if (bufieq(field, "inflate")) {
|
| 201 |
inflate = readnum(content, 1024);
|
| 202 |
if (inflate > INFLATEMAX * 1024)
|
| 203 |
inflate = INFLATEMAX * 1024;
|
| 204 |
} else if (bufieq(field, "rand-hop")) {
|
| 205 |
int randhops, i;
|
| 206 |
randhops = readnum(content, 1);
|
| 207 |
if (randhops > MAXRANDHOPS)
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| 208 |
randhops = MAXRANDHOPS;
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| 209 |
buf_clear(temp);
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| 210 |
if (remixto->length)
|
| 211 |
buf_move(temp, remixto);
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| 212 |
for (i = 0; i < randhops; i++) {
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| 213 |
if (remixto->length > 0)
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| 214 |
buf_appendc(remixto, ',');
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| 215 |
buf_appendc(remixto, '*');
|
| 216 |
}
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| 217 |
if (temp->length) {
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| 218 |
buf_appendc(remixto, ',');
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| 219 |
buf_cat(remixto, temp);
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| 220 |
}
|
| 221 |
}
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| 222 |
#if USE_NSUB
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| 223 |
else if (bufieq(field, "subject"))
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| 224 |
buf_set(subject, content);
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| 225 |
#endif /* USE_NSUB */
|
| 226 |
}
|
| 227 |
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| 228 |
if (cutmarks->length > 0) {
|
| 229 |
BUFFER *cut;
|
| 230 |
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| 231 |
cut = buf_new();
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| 232 |
buf_clear(temp);
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| 233 |
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| 234 |
while ((err = buf_getline(in, line)) != -1 && !buf_eq(line, cutmarks)) {
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| 235 |
buf_cat(temp, line);
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| 236 |
buf_nl(temp);
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| 237 |
}
|
| 238 |
while (err != -1) {
|
| 239 |
err = buf_getline(in, line);
|
| 240 |
if (err == -1 || buf_eq(line, cutmarks)) {
|
| 241 |
t1msg(cut, 0);
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| 242 |
buf_clear(cut);
|
| 243 |
} else {
|
| 244 |
buf_cat(cut, line);
|
| 245 |
buf_nl(cut);
|
| 246 |
}
|
| 247 |
}
|
| 248 |
buf_move(in, temp);
|
| 249 |
buf_clear(cutmarks);
|
| 250 |
}
|
| 251 |
if (encrypted == 1) {
|
| 252 |
#ifdef USE_PGP
|
| 253 |
err = pgp_dearmor(in, temp);
|
| 254 |
if (err == 0) {
|
| 255 |
BUFFER *pass;
|
| 256 |
|
| 257 |
pass = buf_new();
|
| 258 |
buf_sets(pass, PASSPHRASE);
|
| 259 |
err = pgp_decrypt(temp, pass, NULL, NULL, NULL);
|
| 260 |
buf_free(pass);
|
| 261 |
}
|
| 262 |
if (err != -1 && temp->length == 0) {
|
| 263 |
errlog(ERRORMSG, "Empty PGP message.\n");
|
| 264 |
err = -1;
|
| 265 |
goto end;
|
| 266 |
}
|
| 267 |
if (err != -1) {
|
| 268 |
buf_rest(temp, in); /* dangerous, but required for reply blocks */
|
| 269 |
buf_move(in, temp);
|
| 270 |
encrypted = 0;
|
| 271 |
hdr = 0;
|
| 272 |
goto header;
|
| 273 |
}
|
| 274 |
#endif /* USE_PGP */
|
| 275 |
if (testto->length == 0)
|
| 276 |
errlog(ERRORMSG, "Can't decrypt PGP message.\n");
|
| 277 |
buf_appends(test, "Can't decrypt PGP message.\n");
|
| 278 |
}
|
| 279 |
while ((err = buf_lookahead(in, line)) == 1)
|
| 280 |
buf_getline(in, line);
|
| 281 |
#if 0
|
| 282 |
if (err == -1)
|
| 283 |
goto end;
|
| 284 |
#endif /* 0 */
|
| 285 |
|
| 286 |
if (isline(line, HDRMARK) && (hdr == 0 || hdr == 1)) {
|
| 287 |
buf_getline(in, NULL);
|
| 288 |
hdr = 2;
|
| 289 |
goto header;
|
| 290 |
} else if (isline(line, HASHMARK)) {
|
| 291 |
buf_getline(in, NULL);
|
| 292 |
for (;;) {
|
| 293 |
if (buf_lookahead(in, line) == 0 && bufileft(line, "subject:")) {
|
| 294 |
buf_getheader(in, field, content);
|
| 295 |
buf_set(subject, content);
|
| 296 |
}
|
| 297 |
if (buf_getline(in, line) != 0)
|
| 298 |
break;
|
| 299 |
buf_cat(header, line);
|
| 300 |
buf_nl(header);
|
| 301 |
}
|
| 302 |
}
|
| 303 |
if (encrypted == -1) {
|
| 304 |
if (testto->length == 0)
|
| 305 |
errlog(LOG, "Unencrypted message detected.\n");
|
| 306 |
buf_appends(test, "Unencrypted message detected.\n");
|
| 307 |
err = -2;
|
| 308 |
goto end;
|
| 309 |
}
|
| 310 |
if (type == MSG_POST && subject->length == 0)
|
| 311 |
buf_sets(subject, "(no subject)");
|
| 312 |
|
| 313 |
if (to->length > 0)
|
| 314 |
buf_appendf(out, "To: %b\n", to);
|
| 315 |
else if (remixto->length > 0)
|
| 316 |
buf_appendf(out, "To: %b\n", remixto);
|
| 317 |
if (newsgroups->length > 0)
|
| 318 |
buf_appendf(out, "Newsgroups: %b\n", newsgroups);
|
| 319 |
if (subject->length > 0) {
|
| 320 |
#ifdef USE_IDEA
|
| 321 |
if (esub->length > 0)
|
| 322 |
t1_esub(esub, subject);
|
| 323 |
#endif /* USE_IDEA */
|
| 324 |
buf_appendf(out, "Subject: %b\n", subject);
|
| 325 |
}
|
| 326 |
buf_cat(out, header);
|
| 327 |
buf_nl(out);
|
| 328 |
|
| 329 |
#if 0
|
| 330 |
inflate -= in->length;
|
| 331 |
#endif /* 0 */
|
| 332 |
if (inflate > 0) {
|
| 333 |
buf_setrnd(temp, inflate * 3 / 4);
|
| 334 |
encode(temp, 64);
|
| 335 |
buf_appends(in, "\n-----BEGIN GARBAGE-----\n");
|
| 336 |
buf_cat(in, temp);
|
| 337 |
buf_appends(in, "-----END GARBAGE-----\n");
|
| 338 |
}
|
| 339 |
|
| 340 |
if (!(ek->length || ekdes->length || ekcast->length))
|
| 341 |
buf_rest(out, in);
|
| 342 |
else {
|
| 343 |
err = 0;
|
| 344 |
buf_clear(temp);
|
| 345 |
while (buf_getline(in, line) != -1) {
|
| 346 |
if (isline(line, EKMARK)) {
|
| 347 |
buf_cat(out, temp);
|
| 348 |
buf_clear(temp);
|
| 349 |
buf_rest(temp, in);
|
| 350 |
break;
|
| 351 |
}
|
| 352 |
else {
|
| 353 |
buf_cat(temp, line);
|
| 354 |
buf_nl(temp);
|
| 355 |
}
|
| 356 |
}
|
| 357 |
#ifdef USE_PGP
|
| 358 |
if (ekcast->length) {
|
| 359 |
err = pgp_encrypt(PGP_CONVCAST | PGP_TEXT, temp, ekcast, NULL, NULL,
|
| 360 |
NULL, NULL);
|
| 361 |
buf_clear(ekcast);
|
| 362 |
}
|
| 363 |
if (ekdes->length) {
|
| 364 |
err = pgp_encrypt(PGP_CONV3DES | PGP_TEXT, temp, ekdes, NULL, NULL,
|
| 365 |
NULL, NULL);
|
| 366 |
buf_clear(ekdes);
|
| 367 |
}
|
| 368 |
if (ek->length) {
|
| 369 |
err = pgp_encrypt(PGP_CONVENTIONAL | PGP_TEXT, temp, ek, NULL, NULL,
|
| 370 |
NULL, NULL);
|
| 371 |
buf_clear(ek);
|
| 372 |
}
|
| 373 |
buf_appends(out, EKMARK);
|
| 374 |
buf_nl(out);
|
| 375 |
buf_cat(out, temp);
|
| 376 |
#else /* end of USE_PGP */
|
| 377 |
err = -1;
|
| 378 |
#endif /* Else if not USE_PGP */
|
| 379 |
}
|
| 380 |
|
| 381 |
if (type == -1) {
|
| 382 |
buf_appends(test, "No destination.\n");
|
| 383 |
err = -1;
|
| 384 |
}
|
| 385 |
|
| 386 |
end:
|
| 387 |
if (testto->length) {
|
| 388 |
BUFFER *report;
|
| 389 |
int i;
|
| 390 |
|
| 391 |
report = buf_new();
|
| 392 |
buf_sets(report,
|
| 393 |
"Subject: remailer test report\n\nThis is an automated response to the test message you sent to ");
|
| 394 |
buf_appends(report, SHORTNAME);
|
| 395 |
buf_appends(report, ".\nYour test message results follow:\n\n");
|
| 396 |
buf_appends(report, remailer_type);
|
| 397 |
buf_appends(report, VERSION);
|
| 398 |
buf_appends(report, "\n\n");
|
| 399 |
if (err == 0) {
|
| 400 |
err = filtermsg(out);
|
| 401 |
if (err == -1)
|
| 402 |
buf_appends(report, "This remailer cannot deliver the message.\n\n");
|
| 403 |
else {
|
| 404 |
buf_appends(report, "Valid ");
|
| 405 |
buf_appends(report, type == MSG_POST ? "Usenet" : "mail");
|
| 406 |
buf_appends(report, " message.\n");
|
| 407 |
if (remixto->length) {
|
| 408 |
if (remix && MIX)
|
| 409 |
buf_appends(report, "Delivery via Mixmaster: ");
|
| 410 |
else if (remix)
|
| 411 |
buf_appends(report, "Error! Can't remix: ");
|
| 412 |
else
|
| 413 |
buf_appends(report, "Delivery via Cypherpunk remailer: ");
|
| 414 |
buf_cat(report, remixto);
|
| 415 |
buf_nl(report);
|
| 416 |
}
|
| 417 |
else if (type == MSG_POST && strchr(NEWS, '@') && !strchr(NEWS, ' ')) {
|
| 418 |
buf_appendf(report, "News gateway: %s\n", NEWS);
|
| 419 |
}
|
| 420 |
buf_appends(report,
|
| 421 |
"\n=========================================================================\nThe first 20 lines of the message follow:\n");
|
| 422 |
if (err != 1)
|
| 423 |
buf_appendf(report, "From: %s\n", ANONNAME);
|
| 424 |
if (type == MSG_POST && ORGANIZATION[0] != '\0')
|
| 425 |
buf_appendf(report, "Organization: %s\n", ORGANIZATION);
|
| 426 |
}
|
| 427 |
for (i = 0; i < 20 && buf_getline(out, test) != -1; i++)
|
| 428 |
buf_cat(report, test), buf_nl(report);
|
| 429 |
} else {
|
| 430 |
buf_appends(report, "The remailer message is invalid.\n\n");
|
| 431 |
if (test->length) {
|
| 432 |
buf_appends(report, "The following error occurred: ");
|
| 433 |
buf_cat(report, test);
|
| 434 |
buf_nl(report);
|
| 435 |
}
|
| 436 |
}
|
| 437 |
buf_appends(report,
|
| 438 |
"=========================================================================\nThe first 20 lines of your message to the remailer follow:\n");
|
| 439 |
buf_rewind(in);
|
| 440 |
for (i = 0; i < 20 && buf_getline(in, test) != -1; i++)
|
| 441 |
buf_cat(report, test), buf_nl(report);
|
| 442 |
|
| 443 |
sendmail(report, REMAILERNAME, testto);
|
| 444 |
err = 0;
|
| 445 |
buf_free(report);
|
| 446 |
} else if (err == 0 && type != MSG_NULL) {
|
| 447 |
err = 1;
|
| 448 |
if (bufieq(to, REMAILERADDR)) /* don't remix to ourselves */
|
| 449 |
remix = 0;
|
| 450 |
if (remix && remixto->length == 0)
|
| 451 |
buf_set(remixto, to);
|
| 452 |
if (remix && !repgp)
|
| 453 |
err = mix_encrypt(type, out, remixto->data, 1, line);
|
| 454 |
if (err != 0) {
|
| 455 |
if (remix == 1 && !repgp)
|
| 456 |
errlog(NOTICE, "Can't remix -- %b\n", line);
|
| 457 |
else {
|
| 458 |
if (remixto->length)
|
| 459 |
err = t1_encrypt(type, out, remixto->data, 0, 0, line);
|
| 460 |
if (err != 0 && repgp)
|
| 461 |
errlog(NOTICE, "Can't repgp -- %b\n", line);
|
| 462 |
else
|
| 463 |
err = mix_pool(out, type, latent * 60);
|
| 464 |
}
|
| 465 |
}
|
| 466 |
}
|
| 467 |
|
| 468 |
buf_free(field);
|
| 469 |
buf_free(content);
|
| 470 |
buf_free(line);
|
| 471 |
buf_free(to);
|
| 472 |
buf_free(remixto);
|
| 473 |
buf_free(newsgroups);
|
| 474 |
buf_free(subject);
|
| 475 |
buf_free(ek);
|
| 476 |
buf_free(ekcast);
|
| 477 |
buf_free(ekdes);
|
| 478 |
buf_free(esub);
|
| 479 |
buf_free(cutmarks);
|
| 480 |
buf_free(temp);
|
| 481 |
buf_free(out);
|
| 482 |
buf_free(header);
|
| 483 |
buf_free(test);
|
| 484 |
buf_free(testto);
|
| 485 |
return (err);
|
| 486 |
}
|
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