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	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	rabbi	262	$Id: chain1.c,v 1.3 2002/09/18 23:26:16 rabbi 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			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	rabbi	262	#endif /* USE_PGP */
105	rabbi	1	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	rabbi	262	#endif /* DEBUG */
119			return (0);
120	rabbi	1	}
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	rabbi	262	#endif /* USE_PGP */
232	rabbi	1	{
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	rabbi	40	buf_appendf(b, "%s: %s\n", ek ? "::\nAnon-To" : "To",
250	rabbi	1	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	rabbi	262	#endif /* USE_PGP */