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 1.8 2003/09/29 01:06:54 weaselp 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[], int badchains[MAXREM][MAXREM])
{
  FILE *list, *excl;
  int i, listed = 0;
  int n = 0;
  char line[2 * LINELEN], l2[LINELEN], name[LINELEN], *flags;
  BUFFER *starex;

  starex = buf_new();
  excl = mix_openfile(STAREX, "r");
  if (excl != NULL) {
    buf_read(starex, excl);
    fclose(excl);
  }

  list = mix_openfile(TYPE1LIST, "r");
  if (list == NULL) {
    buf_free(starex);
    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';
      remailer[i].flags.star_ex = bufifind(starex, name);
   }
    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);
  parse_badchains(badchains, TYPE1LIST, "Broken type-I remailer chains", remailer, n);
  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 */
  buf_free(starex);
  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 badchains[MAXREM][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, badchains);
  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, badchains, maxrem, 1, chain, chainlen, 0);

  if (chain[0] == -1) {
    clienterr(feedback, "Invalid remailer chain!");
    err = -1;
    goto end;
  }
  if (chain_rand(remailer, badchains, maxrem, chain, chainlen, 1, 0) == -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	rabbi	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	weaselp	592	$Id: chain1.c,v 1.8 2003/09/29 01:06:54 weaselp Exp $ */
10	rabbi	1
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	weaselp	500	int t1_rlist(REMAILER remailer[], int badchains[MAXREM][MAXREM])
20	rabbi	1	{
21	weaselp	387	FILE list, excl;
22	rabbi	1	int i, listed = 0;
23			int n = 0;
24			char line[2 * LINELEN], l2[LINELEN], name[LINELEN], *flags;
25	weaselp	387	BUFFER *starex;
26	rabbi	1
27	weaselp	387	starex = buf_new();
28			excl = mix_openfile(STAREX, "r");
29			if (excl != NULL) {
30			buf_read(starex, excl);
31			fclose(excl);
32			}
33
34	rabbi	1	list = mix_openfile(TYPE1LIST, "r");
35	weaselp	387	if (list == NULL) {
36			buf_free(starex);
37	rabbi	1	return (-1);
38	weaselp	387	}
39
40	rabbi	1	while (fgets(line, sizeof(line), list) != NULL && n < MAXREM) {
41			if (strleft(line, "$remailer") &&
42			strchr(line, '<') && strchr(line, '>') &&
43			strchr(line, '{') && strchr(line, '{') + 4 < strchr(line, '}')) {
44			if (line[strlen(line) - 1] == '\n')
45			line[strlen(line) - 1] = '\0';
46			if (line[strlen(line) - 1] == '\r')
47			line[strlen(line) - 1] = '\0';
48			while (line[strlen(line) - 1] == ' ')
49			line[strlen(line) - 1] = '\0';
50			if (line[strlen(line) - 1] != ';'
51			&& fgets(l2, sizeof(l2), list) != NULL)
52			strcatn(line, l2, LINELEN);
53			flags = strchr(line, '>');
54			strncpy(name, strchr(line, '{') + 2,
55			strchr(line, '}') - strchr(line, '{') - 3);
56			name[strchr(line, '}') - strchr(line, '{') - 3] = '\0';
57			name[20] = '\0';
58
59			for (i = 1; i <= n; i++)
60			if (streq(name, remailer[i].name))
61			break;
62			if (i > n) {
63			/* not in mix list */
64			n++;
65			strcpy(remailer[i].name, name);
66			strncpy(remailer[i].addr, strchr(line, '<') + 1,
67			strchr(line, '>') - strchr(line, '<'));
68			remailer[i].addr[strchr(line, '>') - strchr(line, '<') - 1]
69			= '\0';
70			remailer[i].flags.mix = 0;
71			remailer[i].flags.post = strifind(flags, " post");
72			}
73			remailer[i].flags.cpunk = strfind(flags, " cpunk");
74			remailer[i].flags.pgp = strfind(flags, " pgp");
75			remailer[i].flags.pgponly = strfind(flags, " pgponly");
76			remailer[i].flags.latent = strfind(flags, " latent");
77			remailer[i].flags.middle = strfind(flags, " middle");
78			remailer[i].flags.ek = strfind(flags, " ek");
79			remailer[i].flags.esub = strfind(flags, " esub");
80			remailer[i].flags.newnym = strfind(flags, " newnym");
81			remailer[i].flags.nym = strfind(flags, " nym");
82			remailer[i].info[1].reliability = 0;
83			remailer[i].info[1].latency = 0;
84			remailer[i].info[1].history[0] = '\0';
85	weaselp	387	remailer[i].flags.star_ex = bufifind(starex, name);
86			}
87	rabbi	1	if (strleft(line,
88			"-----------------------------------------------------------------------"))
89			break;
90			}
91			n++; /* ?? */
92			while (fgets(line, sizeof(line), list) != NULL) {
93			if (strlen(line) >= 72 && strlen(line) <= 73)
94			for (i = 1; i < n; i++)
95			if (strleft(line, remailer[i].name) &&
96			line[strlen(remailer[i].name)] == ' ') {
97			strncpy(remailer[i].info[1].history, line + 42, 12);
98			remailer[i].info[1].history[12] = '\0';
99			remailer[i].info[1].reliability = 10000 * N(line[64])
100			+ 1000 * N(line[65]) + 100 * N(line[66])
101			+ 10 * N(line[68]) + N(line[69]);
102			remailer[i].info[1].latency = 36000 * N(line[55])
103			+ 3600 * N(line[56]) + 600 * N(line[58])
104			+ 60 * N(line[59]) + 10 * N(line[61])
105			+ N(line[62]);
106			listed++;
107			}
108			}
109			fclose(list);
110	weaselp	500	parse_badchains(badchains, TYPE1LIST, "Broken type-I remailer chains", remailer, n);
111	rabbi	1	if (listed < 4) /* we have no valid reliability info */
112			for (i = 1; i < n; i++)
113			remailer[i].info[1].reliability = 10000;
114
115			#ifdef USE_PGP
116			pgp_rlist(remailer, n);
117	rabbi	262	#endif /* USE_PGP */
118	weaselp	387	buf_free(starex);
119	rabbi	1	return (n);
120			}
121
122			int t1_ek(BUFFER key, BUFFER seed, int num)
123			{
124			buf_reset(key);
125			buf_appendc(key, (byte) num);
126			buf_cat(key, seed);
127			digest_md5(key, key);
128			encode(key, 0);
129			#ifdef DEBUG
130			fprintf(stderr, "passphrase=%s (%2X%2X%2X%2X %d)\n", key->data,
131			seed->data[0], seed->data[1], seed->data[2], seed->data[3], num);
132	rabbi	262	#endif /* DEBUG */
133	weaselp	332	return (0);
134	rabbi	1	}
135
136			int t1_encrypt(int type, BUFFER message, char chainstr, int latency,
137			BUFFER ek, BUFFER feedback)
138			{
139			BUFFER b, rem, dest, line, field, content;
140			REMAILER remailer[MAXREM];
141	weaselp	500	int badchains[MAXREM][MAXREM];
142	rabbi	1	int maxrem, chainlen = 0;
143			int chain[20];
144			int hop;
145			int hashmark = 0;
146			int err = 0;
147
148			b = buf_new();
149			rem = buf_new();
150			dest = buf_new();
151			line = buf_new();
152			field = buf_new();
153			content = buf_new();
154
155	weaselp	500	maxrem = t1_rlist(remailer, badchains);
156	rabbi	1	if (maxrem < 1) {
157			clienterr(feedback, "No remailer list!");
158			err = -1;
159			goto end;
160			}
161			chainlen = chain_select(chain, chainstr, maxrem, remailer, 1, line);
162			if (chainlen < 1) {
163			if (line->length)
164			clienterr(feedback, line->data);
165			else
166			clienterr(feedback, "Invalid remailer chain!");
167			err = -1;
168			goto end;
169			}
170			if (chain[0] == 0)
171	weaselp	592	chain[0] = chain_randfinal(type, remailer, badchains, maxrem, 1, chain, chainlen, 0);
172	rabbi	1
173			if (chain[0] == -1) {
174			clienterr(feedback, "Invalid remailer chain!");
175			err = -1;
176			goto end;
177			}
178	weaselp	592	if (chain_rand(remailer, badchains, maxrem, chain, chainlen, 1, 0) == -1) {
179	rabbi	1	clienterr(feedback, "No reliable remailers!");
180			err = -1;
181			goto end;
182			}
183			while (buf_getheader(message, field, content) == 0) {
184			hdr_encode(content, 0);
185			if (type == MSG_POST && bufieq(field, "newsgroups") &&
186			remailer[chain[0]].flags.post) {
187			buf_appendf(dest, "Anon-Post-To: %b\n", content);
188			} else if (type == MSG_MAIL && bufieq(field, "to")) {
189			buf_appendf(dest, "Anon-To: %b\n", content);
190			} else {
191			/* paste header */
192			if (type == MSG_POST && bufieq(field, "newsgroups"))
193			buf_appendf(dest, "Anon-To: %s\n", MAILtoNEWS);
194			if (hashmark == 0) {
195			buf_appends(b, "##\n");
196			hashmark = 1;
197			}
198			buf_appendheader(b, field, content);
199			}
200			}
201			buf_nl(b);
202			buf_rest(b, message);
203			buf_move(message, b);
204
205			if (type != MSG_NULL && dest->length == 0) {
206			clienterr(feedback, "No destination address!");
207			err = -1;
208			goto end;
209			}
210			if (type == MSG_NULL) {
211			buf_sets(dest, "Null:\n");
212			}
213			for (hop = 0; hop < chainlen; hop++) {
214			if (hop == 0) {
215			buf_sets(b, "::\n");
216			buf_cat(b, dest);
217			} else {
218			buf_sets(b, "::\nAnon-To: ");
219			buf_appends(b, remailer[chain[hop - 1]].addr);
220			buf_nl(b);
221			}
222			if (remailer[chain[hop]].flags.latent && latency > 0)
223			buf_appendf(b, "Latent-Time: +%d:00r\n", latency);
224			if (ek && remailer[chain[hop]].flags.ek) {
225			t1_ek(line, ek, hop);
226			buf_appendf(b, "Encrypt-Key: %b\n", line);
227			}
228			buf_nl(b);
229			buf_cat(b, message);
230			#ifdef USE_PGP
231			if (remailer[chain[hop]].flags.pgp) {
232			buf_clear(message);
233			buf_clear(rem);
234			buf_setf(rem, "<%s>", remailer[chain[hop]].addr);
235			err = pgp_encrypt(PGP_ENCRYPT \| PGP_REMAIL \| PGP_TEXT, b, rem,
236			NULL, NULL, NULL, NULL);
237			if (err < 0) {
238			buf_setf(line, "No PGP key for remailer %s!\n",
239			remailer[chain[hop]].name);
240			clienterr(feedback, line->data);
241			goto end;
242			}
243			buf_appends(message, "::\nEncrypted: PGP\n\n");
244			buf_cat(message, b);
245			} else
246	rabbi	262	#endif /* USE_PGP */
247	rabbi	1	{
248			if (remailer[chain[hop]].flags.pgponly) {
249			buf_setf(line, "PGP encryption needed for remailer %s!\n",
250			remailer[chain[hop]].name);
251			clienterr(feedback, line->data);
252			goto end;
253			}
254			buf_move(message, b);
255			}
256			if (ek && remailer[chain[hop]].flags.ek)
257			buf_appends(message, "\n**\n");
258			}
259			buf_clear(b);
260			if (chainlen == 0) {
261			buf_appends(b, "::\n");
262			buf_cat(b, dest);
263			} else {
264	rabbi	40	buf_appendf(b, "%s: %s\n", ek ? "::\nAnon-To" : "To",
265	rabbi	1	remailer[chain[chainlen - 1]].addr);
266			}
267			buf_nl(b);
268			buf_cat(b, message);
269			buf_move(message, b);
270			end:
271			buf_free(b);
272			buf_free(rem);
273			buf_free(dest);
274			buf_free(line);
275			buf_free(field);
276			buf_free(content);
277			return (err);
278			}
279
280			#ifdef USE_PGP
281			int t1_getreply(BUFFER msg, BUFFER ek, int len)
282			{
283			BUFFER key, decrypt;
284			int err = -1;
285			int hop = 0;
286
287			key = buf_new();
288			decrypt = buf_new();
289
290			do {
291			t1_ek(key, ek, hop);
292			buf_set(decrypt, msg);
293			if (pgp_decrypt(decrypt, key, NULL, NULL, NULL) == 0
294			&& decrypt->data != NULL)
295			err = 0, buf_move(msg, decrypt);
296			}
297			while (hop++ < len);
298			return (err);
299			}
300
301	rabbi	262	#endif /* USE_PGP */