Mix/Src/chain1.c

/* Mixmaster version 3  --  (C) 1999 Anonymizer Inc.

   Mixmaster may be redistributed and modified under certain conditions.
   This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
   ANY KIND, either express or implied. See the file COPYRIGHT for
   details.

   Encrypt message for Cypherpunk remailer chain
   $Id: chain1.c,v 1.3 2002/09/18 23:26:16 rabbi Exp $ */


#include "mix3.h"
#include "pgp.h"
#include <string.h>
#include <ctype.h>

#define N(X) (isdigit(X) ? (X)-'0' : 0)

int t1_rlist(REMAILER remailer[])
{
  FILE *list;
  int i, listed = 0;
  int n = 0;
  char line[2 * LINELEN], l2[LINELEN], name[LINELEN], *flags;

  list = mix_openfile(TYPE1LIST, "r");
  if (list == NULL)
    return (-1);
  while (fgets(line, sizeof(line), list) != NULL && n < MAXREM) {
    if (strleft(line, "$remailer") &&
        strchr(line, '<') && strchr(line, '>') &&
        strchr(line, '{') && strchr(line, '{') + 4 < strchr(line, '}')) {
      if (line[strlen(line) - 1] == '\n')
        line[strlen(line) - 1] = '\0';
      if (line[strlen(line) - 1] == '\r')
        line[strlen(line) - 1] = '\0';
      while (line[strlen(line) - 1] == ' ')
        line[strlen(line) - 1] = '\0';
      if (line[strlen(line) - 1] != ';'
          && fgets(l2, sizeof(l2), list) != NULL)
        strcatn(line, l2, LINELEN);
      flags = strchr(line, '>');
      strncpy(name, strchr(line, '{') + 2,
              strchr(line, '}') - strchr(line, '{') - 3);
      name[strchr(line, '}') - strchr(line, '{') - 3] = '\0';
      name[20] = '\0';

      for (i = 1; i <= n; i++)
        if (streq(name, remailer[i].name))
          break;
      if (i > n) {
        /* not in mix list */
        n++;
        strcpy(remailer[i].name, name);
        strncpy(remailer[i].addr, strchr(line, '<') + 1,
                strchr(line, '>') - strchr(line, '<'));
        remailer[i].addr[strchr(line, '>') - strchr(line, '<') - 1]
          = '\0';
        remailer[i].flags.mix = 0;
        remailer[i].flags.post = strifind(flags, " post");
      }
      remailer[i].flags.cpunk = strfind(flags, " cpunk");
      remailer[i].flags.pgp = strfind(flags, " pgp");
      remailer[i].flags.pgponly = strfind(flags, " pgponly");
      remailer[i].flags.latent = strfind(flags, " latent");
      remailer[i].flags.middle = strfind(flags, " middle");
      remailer[i].flags.ek = strfind(flags, " ek");
      remailer[i].flags.esub = strfind(flags, " esub");
      remailer[i].flags.newnym = strfind(flags, " newnym");
      remailer[i].flags.nym = strfind(flags, " nym");
      remailer[i].info[1].reliability = 0;
      remailer[i].info[1].latency = 0;
      remailer[i].info[1].history[0] = '\0';
    }
    if (strleft(line,
                "-----------------------------------------------------------------------"))
      break;
  }
  n++;                          /* ?? */
  while (fgets(line, sizeof(line), list) != NULL) {
    if (strlen(line) >= 72 && strlen(line) <= 73)
      for (i = 1; i < n; i++)
        if (strleft(line, remailer[i].name) &&
            line[strlen(remailer[i].name)] == ' ') {
          strncpy(remailer[i].info[1].history, line + 42, 12);
          remailer[i].info[1].history[12] = '\0';
          remailer[i].info[1].reliability = 10000 * N(line[64])
            + 1000 * N(line[65]) + 100 * N(line[66])
            + 10 * N(line[68]) + N(line[69]);
          remailer[i].info[1].latency = 36000 * N(line[55])
            + 3600 * N(line[56]) + 600 * N(line[58])
            + 60 * N(line[59]) + 10 * N(line[61])
            + N(line[62]);
          listed++;
        }
  }
  fclose(list);
  if (listed < 4)               /* we have no valid reliability info */
    for (i = 1; i < n; i++)
      remailer[i].info[1].reliability = 10000;

#ifdef USE_PGP
  pgp_rlist(remailer, n);
#endif /* USE_PGP */
  return (n);
}

int t1_ek(BUFFER *key, BUFFER *seed, int num)
{
  buf_reset(key);
  buf_appendc(key, (byte) num);
  buf_cat(key, seed);
  digest_md5(key, key);
  encode(key, 0);
#ifdef DEBUG
  fprintf(stderr, "passphrase=%s (%2X%2X%2X%2X %d)\n", key->data,
          seed->data[0], seed->data[1], seed->data[2], seed->data[3], num);
#endif /* DEBUG */
  return (0); 
}

int t1_encrypt(int type, BUFFER *message, char *chainstr, int latency,
               BUFFER *ek, BUFFER *feedback)
{
  BUFFER *b, *rem, *dest, *line, *field, *content;
  REMAILER remailer[MAXREM];
  int maxrem, chainlen = 0;
  int chain[20];
  int hop;
  int hashmark = 0;
  int err = 0;

  b = buf_new();
  rem = buf_new();
  dest = buf_new();
  line = buf_new();
  field = buf_new();
  content = buf_new();

  maxrem = t1_rlist(remailer);
  if (maxrem < 1) {
    clienterr(feedback, "No remailer list!");
    err = -1;
    goto end;
  }
  chainlen = chain_select(chain, chainstr, maxrem, remailer, 1, line);
  if (chainlen < 1) {
    if (line->length)
      clienterr(feedback, line->data);
    else
      clienterr(feedback, "Invalid remailer chain!");
    err = -1;
    goto end;
  }
  if (chain[0] == 0)
    chain[0] = chain_randfinal(type, remailer, maxrem, 1);

  if (chain[0] == -1) {
    clienterr(feedback, "Invalid remailer chain!");
    err = -1;
    goto end;
  }
  if (chain_rand(remailer, maxrem, chain, chainlen, 1) == -1) {
    clienterr(feedback, "No reliable remailers!");
    err = -1;
    goto end;
  }
  while (buf_getheader(message, field, content) == 0) {
    hdr_encode(content, 0);
    if (type == MSG_POST && bufieq(field, "newsgroups") &&
        remailer[chain[0]].flags.post) {
      buf_appendf(dest, "Anon-Post-To: %b\n", content);
    } else if (type == MSG_MAIL && bufieq(field, "to")) {
      buf_appendf(dest, "Anon-To: %b\n", content);
    } else {
      /* paste header */
      if (type == MSG_POST && bufieq(field, "newsgroups"))
        buf_appendf(dest, "Anon-To: %s\n", MAILtoNEWS);
      if (hashmark == 0) {
        buf_appends(b, "##\n");
        hashmark = 1;
      }
      buf_appendheader(b, field, content);
    }
  }
  buf_nl(b);
  buf_rest(b, message);
  buf_move(message, b);

  if (type != MSG_NULL && dest->length == 0) {
    clienterr(feedback, "No destination address!");
    err = -1;
    goto end;
  }
  if (type == MSG_NULL) {
    buf_sets(dest, "Null:\n");
  }
  for (hop = 0; hop < chainlen; hop++) {
    if (hop == 0) {
      buf_sets(b, "::\n");
      buf_cat(b, dest);
    } else {
      buf_sets(b, "::\nAnon-To: ");
      buf_appends(b, remailer[chain[hop - 1]].addr);
      buf_nl(b);
    }
    if (remailer[chain[hop]].flags.latent && latency > 0)
      buf_appendf(b, "Latent-Time: +%d:00r\n", latency);
    if (ek && remailer[chain[hop]].flags.ek) {
      t1_ek(line, ek, hop);
      buf_appendf(b, "Encrypt-Key: %b\n", line);
    }
    buf_nl(b);
    buf_cat(b, message);
#ifdef USE_PGP
    if (remailer[chain[hop]].flags.pgp) {
      buf_clear(message);
      buf_clear(rem);
      buf_setf(rem, "<%s>", remailer[chain[hop]].addr);
      err = pgp_encrypt(PGP_ENCRYPT | PGP_REMAIL | PGP_TEXT, b, rem,
                        NULL, NULL, NULL, NULL);
      if (err < 0) {
        buf_setf(line, "No PGP key for remailer %s!\n",
                 remailer[chain[hop]].name);
        clienterr(feedback, line->data);
        goto end;
      }
      buf_appends(message, "::\nEncrypted: PGP\n\n");
      buf_cat(message, b);
    } else
#endif /* USE_PGP */
    {
      if (remailer[chain[hop]].flags.pgponly) {
        buf_setf(line, "PGP encryption needed for remailer %s!\n",
                 remailer[chain[hop]].name);
        clienterr(feedback, line->data);
        goto end;
      }
      buf_move(message, b);
    }
    if (ek && remailer[chain[hop]].flags.ek)
      buf_appends(message, "\n**\n");
  }
  buf_clear(b);
  if (chainlen == 0) {
    buf_appends(b, "::\n");
    buf_cat(b, dest);
  } else {
    buf_appendf(b, "%s: %s\n", ek ? "::\nAnon-To" : "To",
                remailer[chain[chainlen - 1]].addr);
  }
  buf_nl(b);
  buf_cat(b, message);
  buf_move(message, b);
end:
  buf_free(b);
  buf_free(rem);
  buf_free(dest);
  buf_free(line);
  buf_free(field);
  buf_free(content);
  return (err);
}

#ifdef USE_PGP
int t1_getreply(BUFFER *msg, BUFFER *ek, int len)
{
  BUFFER *key, *decrypt;
  int err = -1;
  int hop = 0;

  key = buf_new();
  decrypt = buf_new();

  do {
    t1_ek(key, ek, hop);
    buf_set(decrypt, msg);
    if (pgp_decrypt(decrypt, key, NULL, NULL, NULL) == 0
        && decrypt->data != NULL)
      err = 0, buf_move(msg, decrypt);
  }
  while (hop++ < len);
  return (err);
}

#endif /* USE_PGP */
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 Cypherpunk remailer chain
9	$Id: chain1.c,v 1.3 2002/09/18 23:26:16 rabbi Exp $ */
10
11
12	#include "mix3.h"
13	#include "pgp.h"
14	#include <string.h>
15	#include <ctype.h>
16
17	#define N(X) (isdigit(X) ? (X)-'0' : 0)
18
19	int t1_rlist(REMAILER remailer[])
20	{
21	FILE *list;
22	int i, listed = 0;
23	int n = 0;
24	char line[2 * LINELEN], l2[LINELEN], name[LINELEN], *flags;
25
26	list = mix_openfile(TYPE1LIST, "r");
27	if (list == NULL)
28	return (-1);
29	while (fgets(line, sizeof(line), list) != NULL && n < MAXREM) {
30	if (strleft(line, "$remailer") &&
31	strchr(line, '<') && strchr(line, '>') &&
32	strchr(line, '{') && strchr(line, '{') + 4 < strchr(line, '}')) {
33	if (line[strlen(line) - 1] == '\n')
34	line[strlen(line) - 1] = '\0';
35	if (line[strlen(line) - 1] == '\r')
36	line[strlen(line) - 1] = '\0';
37	while (line[strlen(line) - 1] == ' ')
38	line[strlen(line) - 1] = '\0';
39	if (line[strlen(line) - 1] != ';'
40	&& fgets(l2, sizeof(l2), list) != NULL)
41	strcatn(line, l2, LINELEN);
42	flags = strchr(line, '>');
43	strncpy(name, strchr(line, '{') + 2,
44	strchr(line, '}') - strchr(line, '{') - 3);
45	name[strchr(line, '}') - strchr(line, '{') - 3] = '\0';
46	name[20] = '\0';
47
48	for (i = 1; i <= n; i++)
49	if (streq(name, remailer[i].name))
50	break;
51	if (i > n) {
52	/* not in mix list */
53	n++;
54	strcpy(remailer[i].name, name);
55	strncpy(remailer[i].addr, strchr(line, '<') + 1,
56	strchr(line, '>') - strchr(line, '<'));
57	remailer[i].addr[strchr(line, '>') - strchr(line, '<') - 1]
58	= '\0';
59	remailer[i].flags.mix = 0;
60	remailer[i].flags.post = strifind(flags, " post");
61	}
62	remailer[i].flags.cpunk = strfind(flags, " cpunk");
63	remailer[i].flags.pgp = strfind(flags, " pgp");
64	remailer[i].flags.pgponly = strfind(flags, " pgponly");
65	remailer[i].flags.latent = strfind(flags, " latent");
66	remailer[i].flags.middle = strfind(flags, " middle");
67	remailer[i].flags.ek = strfind(flags, " ek");
68	remailer[i].flags.esub = strfind(flags, " esub");
69	remailer[i].flags.newnym = strfind(flags, " newnym");
70	remailer[i].flags.nym = strfind(flags, " nym");
71	remailer[i].info[1].reliability = 0;
72	remailer[i].info[1].latency = 0;
73	remailer[i].info[1].history[0] = '\0';
74	}
75	if (strleft(line,
76	"-----------------------------------------------------------------------"))
77	break;
78	}
79	n++; /* ?? */
80	while (fgets(line, sizeof(line), list) != NULL) {
81	if (strlen(line) >= 72 && strlen(line) <= 73)
82	for (i = 1; i < n; i++)
83	if (strleft(line, remailer[i].name) &&
84	line[strlen(remailer[i].name)] == ' ') {
85	strncpy(remailer[i].info[1].history, line + 42, 12);
86	remailer[i].info[1].history[12] = '\0';
87	remailer[i].info[1].reliability = 10000 * N(line[64])
88	+ 1000 * N(line[65]) + 100 * N(line[66])
89	+ 10 * N(line[68]) + N(line[69]);
90	remailer[i].info[1].latency = 36000 * N(line[55])
91	+ 3600 * N(line[56]) + 600 * N(line[58])
92	+ 60 * N(line[59]) + 10 * N(line[61])
93	+ N(line[62]);
94	listed++;
95	}
96	}
97	fclose(list);
98	if (listed < 4) /* we have no valid reliability info */
99	for (i = 1; i < n; i++)
100	remailer[i].info[1].reliability = 10000;
101
102	#ifdef USE_PGP
103	pgp_rlist(remailer, n);
104	#endif /* USE_PGP */
105	return (n);
106	}
107
108	int t1_ek(BUFFER key, BUFFER seed, int num)
109	{
110	buf_reset(key);
111	buf_appendc(key, (byte) num);
112	buf_cat(key, seed);
113	digest_md5(key, key);
114	encode(key, 0);
115	#ifdef DEBUG
116	fprintf(stderr, "passphrase=%s (%2X%2X%2X%2X %d)\n", key->data,
117	seed->data[0], seed->data[1], seed->data[2], seed->data[3], num);
118	#endif /* DEBUG */
119	return (0);
120	}
121
122	int t1_encrypt(int type, BUFFER message, char chainstr, int latency,
123	BUFFER ek, BUFFER feedback)
124	{
125	BUFFER b, rem, dest, line, field, content;
126	REMAILER remailer[MAXREM];
127	int maxrem, chainlen = 0;
128	int chain[20];
129	int hop;
130	int hashmark = 0;
131	int err = 0;
132
133	b = buf_new();
134	rem = buf_new();
135	dest = buf_new();
136	line = buf_new();
137	field = buf_new();
138	content = buf_new();
139
140	maxrem = t1_rlist(remailer);
141	if (maxrem < 1) {
142	clienterr(feedback, "No remailer list!");
143	err = -1;
144	goto end;
145	}
146	chainlen = chain_select(chain, chainstr, maxrem, remailer, 1, line);
147	if (chainlen < 1) {
148	if (line->length)
149	clienterr(feedback, line->data);
150	else
151	clienterr(feedback, "Invalid remailer chain!");
152	err = -1;
153	goto end;
154	}
155	if (chain[0] == 0)
156	chain[0] = chain_randfinal(type, remailer, maxrem, 1);
157
158	if (chain[0] == -1) {
159	clienterr(feedback, "Invalid remailer chain!");
160	err = -1;
161	goto end;
162	}
163	if (chain_rand(remailer, maxrem, chain, chainlen, 1) == -1) {
164	clienterr(feedback, "No reliable remailers!");
165	err = -1;
166	goto end;
167	}
168	while (buf_getheader(message, field, content) == 0) {
169	hdr_encode(content, 0);
170	if (type == MSG_POST && bufieq(field, "newsgroups") &&
171	remailer[chain[0]].flags.post) {
172	buf_appendf(dest, "Anon-Post-To: %b\n", content);
173	} else if (type == MSG_MAIL && bufieq(field, "to")) {
174	buf_appendf(dest, "Anon-To: %b\n", content);
175	} else {
176	/* paste header */
177	if (type == MSG_POST && bufieq(field, "newsgroups"))
178	buf_appendf(dest, "Anon-To: %s\n", MAILtoNEWS);
179	if (hashmark == 0) {
180	buf_appends(b, "##\n");
181	hashmark = 1;
182	}
183	buf_appendheader(b, field, content);
184	}
185	}
186	buf_nl(b);
187	buf_rest(b, message);
188	buf_move(message, b);
189
190	if (type != MSG_NULL && dest->length == 0) {
191	clienterr(feedback, "No destination address!");
192	err = -1;
193	goto end;
194	}
195	if (type == MSG_NULL) {
196	buf_sets(dest, "Null:\n");
197	}
198	for (hop = 0; hop < chainlen; hop++) {
199	if (hop == 0) {
200	buf_sets(b, "::\n");
201	buf_cat(b, dest);
202	} else {
203	buf_sets(b, "::\nAnon-To: ");
204	buf_appends(b, remailer[chain[hop - 1]].addr);
205	buf_nl(b);
206	}
207	if (remailer[chain[hop]].flags.latent && latency > 0)
208	buf_appendf(b, "Latent-Time: +%d:00r\n", latency);
209	if (ek && remailer[chain[hop]].flags.ek) {
210	t1_ek(line, ek, hop);
211	buf_appendf(b, "Encrypt-Key: %b\n", line);
212	}
213	buf_nl(b);
214	buf_cat(b, message);
215	#ifdef USE_PGP
216	if (remailer[chain[hop]].flags.pgp) {
217	buf_clear(message);
218	buf_clear(rem);
219	buf_setf(rem, "<%s>", remailer[chain[hop]].addr);
220	err = pgp_encrypt(PGP_ENCRYPT \| PGP_REMAIL \| PGP_TEXT, b, rem,
221	NULL, NULL, NULL, NULL);
222	if (err < 0) {
223	buf_setf(line, "No PGP key for remailer %s!\n",
224	remailer[chain[hop]].name);
225	clienterr(feedback, line->data);
226	goto end;
227	}
228	buf_appends(message, "::\nEncrypted: PGP\n\n");
229	buf_cat(message, b);
230	} else
231	#endif /* USE_PGP */
232	{
233	if (remailer[chain[hop]].flags.pgponly) {
234	buf_setf(line, "PGP encryption needed for remailer %s!\n",
235	remailer[chain[hop]].name);
236	clienterr(feedback, line->data);
237	goto end;
238	}
239	buf_move(message, b);
240	}
241	if (ek && remailer[chain[hop]].flags.ek)
242	buf_appends(message, "\n**\n");
243	}
244	buf_clear(b);
245	if (chainlen == 0) {
246	buf_appends(b, "::\n");
247	buf_cat(b, dest);
248	} else {
249	buf_appendf(b, "%s: %s\n", ek ? "::\nAnon-To" : "To",
250	remailer[chain[chainlen - 1]].addr);
251	}
252	buf_nl(b);
253	buf_cat(b, message);
254	buf_move(message, b);
255	end:
256	buf_free(b);
257	buf_free(rem);
258	buf_free(dest);
259	buf_free(line);
260	buf_free(field);
261	buf_free(content);
262	return (err);
263	}
264
265	#ifdef USE_PGP
266	int t1_getreply(BUFFER msg, BUFFER ek, int len)
267	{
268	BUFFER key, decrypt;
269	int err = -1;
270	int hop = 0;
271
272	key = buf_new();
273	decrypt = buf_new();
274
275	do {
276	t1_ek(key, ek, hop);
277	buf_set(decrypt, msg);
278	if (pgp_decrypt(decrypt, key, NULL, NULL, NULL) == 0
279	&& decrypt->data != NULL)
280	err = 0, buf_move(msg, decrypt);
281	}
282	while (hop++ < len);
283	return (err);
284	}
285
286	#endif /* USE_PGP */