ircd-hybrid-8/modules/m_cryptlink.c

/*
 *  ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
 *  m_cryptlink.c: Used to negotiate an encrypted link.
 *
 *  Copyright (C) 2002 by the past and present ircd coders, and others.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 *  $Id$
 */

/*
 * CRYPTLINK protocol.
 *
 * Please see doc/cryptlink.txt for a description of this protocol.
 *
 */

#include "stdinc.h"

#ifdef HAVE_LIBCRYPTO
#include "list.h"
#include "client.h"      /* client struct */
#include "ircd.h"        /* me */
#include "modules.h"
#include "numeric.h"     /* ERR_xxx */
#include "send.h"        /* sendto_one */
#include <openssl/rsa.h> /* rsa.h is implicit when building this */
#include "rsa.h"
#include "parse.h"
#include "irc_string.h"  /* strncpy_irc */
#include "memory.h"
#include "event.h"
#include "hash.h"        /* add_to_client_hash_table */
#include "s_conf.h"      /* struct AccessItem */
#include "s_log.h"       /* log level defines */
#include "s_serv.h"      /* server_estab, check_server, my_name_for_link */
#include "motd.h"


static char *parse_cryptserv_args(struct Client *client_p,
                                  char *parv[], int parc, char *info,
                                  char *key);

static void cryptlink_serv(struct Client *, struct Client *, int, char **);
static void cryptlink_auth(struct Client *, struct Client *, int, char **);

struct CryptLinkStruct
{
  const char *cmd;   /* CRYPTLINK <command> to match */
  void (*handler)(); /* Function to call             */
};

static struct CryptLinkStruct cryptlink_cmd_table[] =
{
  /* command    function        */
  { "AUTH",     cryptlink_auth, },
  { "SERV",     cryptlink_serv, },
  /* End of table */
  { NULL,       NULL,   }
};

/* mr_cryptlink - CRYPTLINK message handler
 *      parv[0] == CRYPTLINK
 *      parv[1] = command (SERV, AUTH)
 *      parv[2] = Parameters specific to each command (parv[1]):
 *                   SERV - parc must be >= 5
 *                          parv[0] == CRYPTLINK
 *                          parv[1] == SERV
 *                          parv[2] == server name
 *                          parv[3] == keyphrase
 *                          parv[4] == :server info (M-line)
 *                   AUTH - parc must be >= 4
 *                          parv[0] == CRYPTLINK
 *                          parv[1] == AUTH
 *                          parv[2] == cipher (eg. BF/168)
 *                          parv[3] == keyphrase
 */
static void
mr_cryptlink(struct Client *client_p, struct Client *source_p,
             int parc, char *parv[])
{
  int i;

  for (i = 0; cryptlink_cmd_table[i].handler; i++)
  {
    /* Traverse through the command table */
    if (!irccmp(cryptlink_cmd_table[i].cmd, parv[1]))
    {
      /*
       * Match found.  Time to execute the function
       */
      cryptlink_cmd_table[i].handler(client_p, source_p, parc, parv);
    }
  }
}

/*
 * cryptlink_auth - CRYPTLINK AUTH message handler
 *        parv[1] = secret key
 */
static void
cryptlink_auth(struct Client *client_p, struct Client *source_p,
               int parc, char *parv[])
{
  struct EncCapability *ecap;
  struct ConfItem *conf;
  struct AccessItem *aconf;
  int   enc_len;
  int   len;
  unsigned char *enc;
  unsigned char *key;

  if (parc < 4)
  {
    cryptlink_error(client_p, "AUTH", "Invalid params",
                    "CRYPTLINK AUTH - Invalid params");
    return;
  }

  if (!IsWaitAuth(client_p))
    return;

  for (ecap = CipherTable; ecap->name; ecap++)
  {
    if ((!irccmp(ecap->name, parv[2])) &&
        (IsCapableEnc(client_p, ecap->cap)))
    {
      client_p->localClient->in_cipher = ecap;
      break;
    }
  }

  if (client_p->localClient->in_cipher == NULL)
  {
    cryptlink_error(client_p, "AUTH", "Invalid cipher", "Invalid cipher");
    return;
  }

  if (!(enc_len = unbase64_block(&enc, parv[3], strlen(parv[3]))))
  {
    cryptlink_error(client_p, "AUTH",
                    "Could not base64 decode response",
                    "Malformed CRYPTLINK AUTH reply");
    return;
  }

  if (verify_private_key() == -1)
  {
    sendto_realops_flags(UMODE_ALL, L_ADMIN,
      "verify_private_key() returned -1.  Check log for information.");
  }

  key = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
  len = RSA_private_decrypt(enc_len, (unsigned char *)enc,(unsigned char *)key,
                            ServerInfo.rsa_private_key,
                            RSA_PKCS1_PADDING);

  if (len < client_p->localClient->in_cipher->keylen)
  {
    report_crypto_errors();
    if (len < 0)
    {
      cryptlink_error(client_p, "AUTH",
                      "Decryption failed",
                      "Malformed CRYPTLINK AUTH reply");
    }
    else
    {
      cryptlink_error(client_p, "AUTH",
                      "Not enough random data sent",
                      "Malformed CRYPTLINK AUTH reply");
    }
    MyFree(enc);
    MyFree(key);
    return;
  }

  if (memcmp(key, client_p->localClient->in_key,
             client_p->localClient->in_cipher->keylen) != 0)
  {
    cryptlink_error(client_p, "AUTH",
                    "Unauthorized server connection attempt",
                    "Malformed CRYPTLINK AUTH reply");
    return;
  }

  conf = find_conf_name(&client_p->localClient->confs,
                         client_p->name, SERVER_TYPE);

  if (conf == NULL)
  {
    cryptlink_error(client_p, "AUTH",
                    "Lost C-line for server",
                    "Lost C-line");
    return;
  }

  aconf = (struct AccessItem *)map_to_conf(conf);

  if (!(client_p->localClient->out_cipher ||
      (client_p->localClient->out_cipher = check_cipher(client_p, aconf))))
  {
    cryptlink_error(client_p, "AUTH",
                    "Couldn't find compatible cipher",
                    "Couldn't find compatible cipher");
    return;
  }

  /* set hopcount */
  client_p->hopcount = 1;

  SetCryptIn(client_p);
  ClearWaitAuth(client_p);
  server_estab(client_p);
}

/*
 * cryptlink_serv - CRYPTLINK SERV message handler
 *        parv[0] == CRYPTLINK
 *        parv[1] == SERV
 *        parv[2] == server name
 *        parv[3] == keyphrase
 *        parv[4] == :server info (M-line)
 */
static void
cryptlink_serv(struct Client *client_p, struct Client *source_p,
               int parc, char *parv[])
{
  char info[REALLEN + 1];
  char *name;
  struct Client *target_p;
  char *key = client_p->localClient->out_key;
  unsigned char *b64_key;
  struct ConfItem *conf;
  struct AccessItem *aconf;
  char *encrypted;
  const char *p;
  int enc_len;

  /*
  if (client_p->name[0] != 0)
  return;
  */

  if ((parc < 5) || (*parv[4] == '\0'))
  {
    cryptlink_error(client_p, "SERV", "Invalid params",
                    "CRYPTLINK SERV - Invalid params");
    return;
  }

  if ((name = parse_cryptserv_args(client_p, parv, parc, info, key)) == NULL)
  {
    cryptlink_error(client_p, "SERV", "Invalid params",
                    "CRYPTLINK SERV - Invalid params");
    return;
  }

  /* CRYPTLINK SERV support => TS support */
  client_p->tsinfo = TS_DOESTS;

  if (!valid_servname(name))
  {
    exit_client(client_p, client_p, "Bogus server name");
    return;
  }

  /* Now we just have to call check_server and everything should be
   * checked for us... -A1kmm. */
  switch (check_server(name, client_p, CHECK_SERVER_CRYPTLINK))
  {
    case -1:
      if (ConfigFileEntry.warn_no_nline)
      {
        cryptlink_error(client_p, "SERV",
          "Unauthorized server connection attempt: No entry for server",
          NULL);
      }
      exit_client(client_p, client_p, "Invalid server name");
      return;
      break;
    case -2:
      cryptlink_error(client_p, "SERV",
        "Unauthorized server connection attempt: CRYPTLINK not "
                                      "enabled on remote server",
        "CRYPTLINK not enabled");
      return;
      break;
    case -3:
      cryptlink_error(client_p, "SERV",
        "Unauthorized server connection attempt: Invalid host",
        "Invalid host");
      return;
      break;
  }

  if ((target_p = hash_find_server(name)))
  {
    /*
     * This link is trying feed me a server that I already have
     * access through another path -- multiple paths not accepted
     * currently, kill this link immediately!!
     *
     * Rather than KILL the link which introduced it, KILL the
     * youngest of the two links. -avalon
     *
     * Definitely don't do that here. This is from an unregistered
     * connect - A1kmm.
     */
    cryptlink_error(client_p, "SERV",
                    "Attempt to re-introduce existing server",
                    "Server Exists");
    return;
  }

  conf = find_conf_name(&client_p->localClient->confs,
                        name, SERVER_TYPE);
  if (conf == NULL)
  {
    cryptlink_error(client_p, "AUTH",
                    "Lost C-line for server",
                    "Lost C-line" );
    return;
  }

  /*
   * if we are connecting (Handshake), we already have the name from the
   * connect {} block in client_p->name
   */
  strlcpy(client_p->name, name, sizeof(client_p->name));

  p = info;

  if (!strncmp(info, "(H)", 3))
  {
    SetHidden(client_p);

    if ((p = strchr(info, ' ')) != NULL)
    {
      p++;
      if (*p == '\0')
        p = "(Unknown Location)";
    }
    else
      p = "(Unknown Location)";
  }

  strlcpy(client_p->info, p, sizeof(client_p->info));
  client_p->hopcount = 0;

  aconf = (struct AccessItem *)map_to_conf(conf);

  if (!(client_p->localClient->out_cipher ||
      (client_p->localClient->out_cipher = check_cipher(client_p, aconf))))
  {
    cryptlink_error(client_p, "AUTH",
                    "Couldn't find compatible cipher",
                    "Couldn't find compatible cipher");
    return;
  }

  encrypted = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
  enc_len   = RSA_public_encrypt(client_p->localClient->out_cipher->keylen,
                               (unsigned char *)key,
                               (unsigned char *)encrypted,
                               aconf->rsa_public_key,
                               RSA_PKCS1_PADDING);

  if (enc_len <= 0)
  {
    report_crypto_errors();
    MyFree(encrypted);
    cryptlink_error(client_p, "AUTH",
                    "Couldn't encrypt data",
                    "Couldn't encrypt data");
    return;
  }

  base64_block(&b64_key, encrypted, enc_len);

  MyFree(encrypted);

  if (!IsWaitAuth(client_p))
    cryptlink_init(client_p, conf, NULL);

  sendto_one(client_p, "CRYPTLINK AUTH %s %s",
             client_p->localClient->out_cipher->name,
             b64_key);

  /* needed for old servers that can't shove data back into slink */
  send_queued_write(client_p);

  SetCryptOut(client_p);
  MyFree(b64_key);
}

/* parse_cryptserv_args()
 *
 * inputs       - parv parameters
 *              - parc count
 *              - info string (to be filled in by this routine)
 *              - key (to be filled in by this routine)
 * output       - NULL if invalid params, server name otherwise
 * side effects - parv[2] is trimmed to HOSTLEN size if needed.
 */
static char *
parse_cryptserv_args(struct Client *client_p, char *parv[],
                     int parc, char *info, char *key)
{
  char *name;
  unsigned char *tmp, *out;
  int len;
  int decoded_len;

  info[0] = '\0';

  name = parv[2];

  /* parv[2] contains encrypted auth data */
  if (!(decoded_len = unbase64_block(&tmp, parv[3],
                                     strlen(parv[3]))))
  {
    cryptlink_error(client_p, "SERV",
                    "Couldn't base64 decode data",
                    NULL);
    return(NULL);
  }

  if (verify_private_key() == -1)
  {
    sendto_realops_flags(UMODE_ALL, L_ADMIN,
      "verify_private_key() returned -1.  Check log for information.");
  }

  if (ServerInfo.rsa_private_key == NULL)
  {
    cryptlink_error(client_p, "SERV", "No local private key found", NULL);
    return(NULL);
  }

  out = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
  len = RSA_private_decrypt(decoded_len, tmp, out,
                            ServerInfo.rsa_private_key,
                            RSA_PKCS1_PADDING);

  MyFree(tmp);

  if (len < CIPHERKEYLEN)
  {
    report_crypto_errors();
    if (len < 0)
    {
      cryptlink_error(client_p, "AUTH", "Decryption failed", NULL);
    }
    else
    {
      cryptlink_error(client_p, "AUTH", "Not enough random data sent", NULL);
    }
    MyFree(out);
    return(NULL);
  }

  memcpy(key, out, CIPHERKEYLEN);
  MyFree(out);

  strlcpy(info, parv[4], REALLEN + 1);

  if (strlen(name) > HOSTLEN)
    name[HOSTLEN] = '\0';

  return(name);
}

static struct Message cryptlink_msgtab = {
  "CRYPTLINK", 0, 0, 4, MAXPARA, MFLG_SLOW | MFLG_UNREG, 0,
  {mr_cryptlink, m_ignore, rfc1459_command_send_error, m_ignore, m_ignore, m_ignore}
};

static void
module_init(void)
{
  mod_add_cmd(&cryptlink_msgtab);
}

static void
module_exit(void)
{
  mod_del_cmd(&cryptlink_msgtab);
}

struct module module_entry = {
  .node    = { NULL, NULL, NULL },
  .name    = NULL,
  .version = "$Revision$",
  .handle  = NULL,
  .modinit = module_init,
  .modexit = module_exit,
  .flags   = 0
};
#endif
Revision:	1243
Committed:	Fri Sep 30 10:47:53 2011 UTC (14 years, 9 months ago) by michael
Content type:	text/x-csrc
File size:	13737 byte(s)
Log Message:	- move content of msg.h, ircd_handler.h and handlers.h into parse.h and remove headers accordingly - killed common.h - remove m_killhost.c and m_flags.c from contrib/ - sort out unused header includes here and there
#	Content
1	/*
2	* ircd-hybrid: an advanced Internet Relay Chat Daemon(ircd).
3	* m_cryptlink.c: Used to negotiate an encrypted link.
4	*
5	* Copyright (C) 2002 by the past and present ircd coders, and others.
6	*
7	* This program is free software; you can redistribute it and/or modify
8	* it under the terms of the GNU General Public License as published by
9	* the Free Software Foundation; either version 2 of the License, or
10	* (at your option) any later version.
11	*
12	* This program is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	* GNU General Public License for more details.
16	*
17	* You should have received a copy of the GNU General Public License
18	* along with this program; if not, write to the Free Software
19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20	* USA
21	*
22	* $Id$
23	*/
24
25	/*
26	* CRYPTLINK protocol.
27	*
28	* Please see doc/cryptlink.txt for a description of this protocol.
29	*
30	*/
31
32	#include "stdinc.h"
33
34	#ifdef HAVE_LIBCRYPTO
35	#include "list.h"
36	#include "client.h" /* client struct */
37	#include "ircd.h" /* me */
38	#include "modules.h"
39	#include "numeric.h" /* ERR_xxx */
40	#include "send.h" /* sendto_one */
41	#include <openssl/rsa.h> /* rsa.h is implicit when building this */
42	#include "rsa.h"
43	#include "parse.h"
44	#include "irc_string.h" /* strncpy_irc */
45	#include "memory.h"
46	#include "event.h"
47	#include "hash.h" /* add_to_client_hash_table */
48	#include "s_conf.h" /* struct AccessItem */
49	#include "s_log.h" /* log level defines */
50	#include "s_serv.h" /* server_estab, check_server, my_name_for_link */
51	#include "motd.h"
52
53
54	static char parse_cryptserv_args(struct Client client_p,
55	char parv[], int parc, char info,
56	char *key);
57
58	static void cryptlink_serv(struct Client , struct Client , int, char **);
59	static void cryptlink_auth(struct Client , struct Client , int, char **);
60
61	struct CryptLinkStruct
62	{
63	const char cmd; / CRYPTLINK <command> to match */
64	void (handler)(); / Function to call */
65	};
66
67	static struct CryptLinkStruct cryptlink_cmd_table[] =
68	{
69	/* command function */
70	{ "AUTH", cryptlink_auth, },
71	{ "SERV", cryptlink_serv, },
72	/* End of table */
73	{ NULL, NULL, }
74	};
75
76	/* mr_cryptlink - CRYPTLINK message handler
77	* parv[0] == CRYPTLINK
78	* parv[1] = command (SERV, AUTH)
79	* parv[2] = Parameters specific to each command (parv[1]):
80	* SERV - parc must be >= 5
81	* parv[0] == CRYPTLINK
82	* parv[1] == SERV
83	* parv[2] == server name
84	* parv[3] == keyphrase
85	* parv[4] == :server info (M-line)
86	* AUTH - parc must be >= 4
87	* parv[0] == CRYPTLINK
88	* parv[1] == AUTH
89	* parv[2] == cipher (eg. BF/168)
90	* parv[3] == keyphrase
91	*/
92	static void
93	mr_cryptlink(struct Client client_p, struct Client source_p,
94	int parc, char *parv[])
95	{
96	int i;
97
98	for (i = 0; cryptlink_cmd_table[i].handler; i++)
99	{
100	/* Traverse through the command table */
101	if (!irccmp(cryptlink_cmd_table[i].cmd, parv[1]))
102	{
103	/*
104	* Match found. Time to execute the function
105	*/
106	cryptlink_cmd_table[i].handler(client_p, source_p, parc, parv);
107	}
108	}
109	}
110
111	/*
112	* cryptlink_auth - CRYPTLINK AUTH message handler
113	* parv[1] = secret key
114	*/
115	static void
116	cryptlink_auth(struct Client client_p, struct Client source_p,
117	int parc, char *parv[])
118	{
119	struct EncCapability *ecap;
120	struct ConfItem *conf;
121	struct AccessItem *aconf;
122	int enc_len;
123	int len;
124	unsigned char *enc;
125	unsigned char *key;
126
127	if (parc < 4)
128	{
129	cryptlink_error(client_p, "AUTH", "Invalid params",
130	"CRYPTLINK AUTH - Invalid params");
131	return;
132	}
133
134	if (!IsWaitAuth(client_p))
135	return;
136
137	for (ecap = CipherTable; ecap->name; ecap++)
138	{
139	if ((!irccmp(ecap->name, parv[2])) &&
140	(IsCapableEnc(client_p, ecap->cap)))
141	{
142	client_p->localClient->in_cipher = ecap;
143	break;
144	}
145	}
146
147	if (client_p->localClient->in_cipher == NULL)
148	{
149	cryptlink_error(client_p, "AUTH", "Invalid cipher", "Invalid cipher");
150	return;
151	}
152
153	if (!(enc_len = unbase64_block(&enc, parv[3], strlen(parv[3]))))
154	{
155	cryptlink_error(client_p, "AUTH",
156	"Could not base64 decode response",
157	"Malformed CRYPTLINK AUTH reply");
158	return;
159	}
160
161	if (verify_private_key() == -1)
162	{
163	sendto_realops_flags(UMODE_ALL, L_ADMIN,
164	"verify_private_key() returned -1. Check log for information.");
165	}
166
167	key = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
168	len = RSA_private_decrypt(enc_len, (unsigned char )enc,(unsigned char )key,
169	ServerInfo.rsa_private_key,
170	RSA_PKCS1_PADDING);
171
172	if (len < client_p->localClient->in_cipher->keylen)
173	{
174	report_crypto_errors();
175	if (len < 0)
176	{
177	cryptlink_error(client_p, "AUTH",
178	"Decryption failed",
179	"Malformed CRYPTLINK AUTH reply");
180	}
181	else
182	{
183	cryptlink_error(client_p, "AUTH",
184	"Not enough random data sent",
185	"Malformed CRYPTLINK AUTH reply");
186	}
187	MyFree(enc);
188	MyFree(key);
189	return;
190	}
191
192	if (memcmp(key, client_p->localClient->in_key,
193	client_p->localClient->in_cipher->keylen) != 0)
194	{
195	cryptlink_error(client_p, "AUTH",
196	"Unauthorized server connection attempt",
197	"Malformed CRYPTLINK AUTH reply");
198	return;
199	}
200
201	conf = find_conf_name(&client_p->localClient->confs,
202	client_p->name, SERVER_TYPE);
203
204	if (conf == NULL)
205	{
206	cryptlink_error(client_p, "AUTH",
207	"Lost C-line for server",
208	"Lost C-line");
209	return;
210	}
211
212	aconf = (struct AccessItem *)map_to_conf(conf);
213
214	if (!(client_p->localClient->out_cipher \|\|
215	(client_p->localClient->out_cipher = check_cipher(client_p, aconf))))
216	{
217	cryptlink_error(client_p, "AUTH",
218	"Couldn't find compatible cipher",
219	"Couldn't find compatible cipher");
220	return;
221	}
222
223	/* set hopcount */
224	client_p->hopcount = 1;
225
226	SetCryptIn(client_p);
227	ClearWaitAuth(client_p);
228	server_estab(client_p);
229	}
230
231	/*
232	* cryptlink_serv - CRYPTLINK SERV message handler
233	* parv[0] == CRYPTLINK
234	* parv[1] == SERV
235	* parv[2] == server name
236	* parv[3] == keyphrase
237	* parv[4] == :server info (M-line)
238	*/
239	static void
240	cryptlink_serv(struct Client client_p, struct Client source_p,
241	int parc, char *parv[])
242	{
243	char info[REALLEN + 1];
244	char *name;
245	struct Client *target_p;
246	char *key = client_p->localClient->out_key;
247	unsigned char *b64_key;
248	struct ConfItem *conf;
249	struct AccessItem *aconf;
250	char *encrypted;
251	const char *p;
252	int enc_len;
253
254	/*
255	if (client_p->name[0] != 0)
256	return;
257	*/
258
259	if ((parc < 5) \|\| (*parv[4] == '\0'))
260	{
261	cryptlink_error(client_p, "SERV", "Invalid params",
262	"CRYPTLINK SERV - Invalid params");
263	return;
264	}
265
266	if ((name = parse_cryptserv_args(client_p, parv, parc, info, key)) == NULL)
267	{
268	cryptlink_error(client_p, "SERV", "Invalid params",
269	"CRYPTLINK SERV - Invalid params");
270	return;
271	}
272
273	/* CRYPTLINK SERV support => TS support */
274	client_p->tsinfo = TS_DOESTS;
275
276	if (!valid_servname(name))
277	{
278	exit_client(client_p, client_p, "Bogus server name");
279	return;
280	}
281
282	/* Now we just have to call check_server and everything should be
283	* checked for us... -A1kmm. */
284	switch (check_server(name, client_p, CHECK_SERVER_CRYPTLINK))
285	{
286	case -1:
287	if (ConfigFileEntry.warn_no_nline)
288	{
289	cryptlink_error(client_p, "SERV",
290	"Unauthorized server connection attempt: No entry for server",
291	NULL);
292	}
293	exit_client(client_p, client_p, "Invalid server name");
294	return;
295	break;
296	case -2:
297	cryptlink_error(client_p, "SERV",
298	"Unauthorized server connection attempt: CRYPTLINK not "
299	"enabled on remote server",
300	"CRYPTLINK not enabled");
301	return;
302	break;
303	case -3:
304	cryptlink_error(client_p, "SERV",
305	"Unauthorized server connection attempt: Invalid host",
306	"Invalid host");
307	return;
308	break;
309	}
310
311	if ((target_p = hash_find_server(name)))
312	{
313	/*
314	* This link is trying feed me a server that I already have
315	* access through another path -- multiple paths not accepted
316	* currently, kill this link immediately!!
317	*
318	* Rather than KILL the link which introduced it, KILL the
319	* youngest of the two links. -avalon
320	*
321	* Definitely don't do that here. This is from an unregistered
322	* connect - A1kmm.
323	*/
324	cryptlink_error(client_p, "SERV",
325	"Attempt to re-introduce existing server",
326	"Server Exists");
327	return;
328	}
329
330	conf = find_conf_name(&client_p->localClient->confs,
331	name, SERVER_TYPE);
332	if (conf == NULL)
333	{
334	cryptlink_error(client_p, "AUTH",
335	"Lost C-line for server",
336	"Lost C-line" );
337	return;
338	}
339
340	/*
341	* if we are connecting (Handshake), we already have the name from the
342	* connect {} block in client_p->name
343	*/
344	strlcpy(client_p->name, name, sizeof(client_p->name));
345
346	p = info;
347
348	if (!strncmp(info, "(H)", 3))
349	{
350	SetHidden(client_p);
351
352	if ((p = strchr(info, ' ')) != NULL)
353	{
354	p++;
355	if (*p == '\0')
356	p = "(Unknown Location)";
357	}
358	else
359	p = "(Unknown Location)";
360	}
361
362	strlcpy(client_p->info, p, sizeof(client_p->info));
363	client_p->hopcount = 0;
364
365	aconf = (struct AccessItem *)map_to_conf(conf);
366
367	if (!(client_p->localClient->out_cipher \|\|
368	(client_p->localClient->out_cipher = check_cipher(client_p, aconf))))
369	{
370	cryptlink_error(client_p, "AUTH",
371	"Couldn't find compatible cipher",
372	"Couldn't find compatible cipher");
373	return;
374	}
375
376	encrypted = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
377	enc_len = RSA_public_encrypt(client_p->localClient->out_cipher->keylen,
378	(unsigned char *)key,
379	(unsigned char *)encrypted,
380	aconf->rsa_public_key,
381	RSA_PKCS1_PADDING);
382
383	if (enc_len <= 0)
384	{
385	report_crypto_errors();
386	MyFree(encrypted);
387	cryptlink_error(client_p, "AUTH",
388	"Couldn't encrypt data",
389	"Couldn't encrypt data");
390	return;
391	}
392
393	base64_block(&b64_key, encrypted, enc_len);
394
395	MyFree(encrypted);
396
397	if (!IsWaitAuth(client_p))
398	cryptlink_init(client_p, conf, NULL);
399
400	sendto_one(client_p, "CRYPTLINK AUTH %s %s",
401	client_p->localClient->out_cipher->name,
402	b64_key);
403
404	/* needed for old servers that can't shove data back into slink */
405	send_queued_write(client_p);
406
407	SetCryptOut(client_p);
408	MyFree(b64_key);
409	}
410
411	/* parse_cryptserv_args()
412	*
413	* inputs - parv parameters
414	* - parc count
415	* - info string (to be filled in by this routine)
416	* - key (to be filled in by this routine)
417	* output - NULL if invalid params, server name otherwise
418	* side effects - parv[2] is trimmed to HOSTLEN size if needed.
419	*/
420	static char *
421	parse_cryptserv_args(struct Client client_p, char parv[],
422	int parc, char info, char key)
423	{
424	char *name;
425	unsigned char tmp, out;
426	int len;
427	int decoded_len;
428
429	info[0] = '\0';
430
431	name = parv[2];
432
433	/* parv[2] contains encrypted auth data */
434	if (!(decoded_len = unbase64_block(&tmp, parv[3],
435	strlen(parv[3]))))
436	{
437	cryptlink_error(client_p, "SERV",
438	"Couldn't base64 decode data",
439	NULL);
440	return(NULL);
441	}
442
443	if (verify_private_key() == -1)
444	{
445	sendto_realops_flags(UMODE_ALL, L_ADMIN,
446	"verify_private_key() returned -1. Check log for information.");
447	}
448
449	if (ServerInfo.rsa_private_key == NULL)
450	{
451	cryptlink_error(client_p, "SERV", "No local private key found", NULL);
452	return(NULL);
453	}
454
455	out = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
456	len = RSA_private_decrypt(decoded_len, tmp, out,
457	ServerInfo.rsa_private_key,
458	RSA_PKCS1_PADDING);
459
460	MyFree(tmp);
461
462	if (len < CIPHERKEYLEN)
463	{
464	report_crypto_errors();
465	if (len < 0)
466	{
467	cryptlink_error(client_p, "AUTH", "Decryption failed", NULL);
468	}
469	else
470	{
471	cryptlink_error(client_p, "AUTH", "Not enough random data sent", NULL);
472	}
473	MyFree(out);
474	return(NULL);
475	}
476
477	memcpy(key, out, CIPHERKEYLEN);
478	MyFree(out);
479
480	strlcpy(info, parv[4], REALLEN + 1);
481
482	if (strlen(name) > HOSTLEN)
483	name[HOSTLEN] = '\0';
484
485	return(name);
486	}
487
488	static struct Message cryptlink_msgtab = {
489	"CRYPTLINK", 0, 0, 4, MAXPARA, MFLG_SLOW \| MFLG_UNREG, 0,
490	{mr_cryptlink, m_ignore, rfc1459_command_send_error, m_ignore, m_ignore, m_ignore}
491	};
492
493	static void
494	module_init(void)
495	{
496	mod_add_cmd(&cryptlink_msgtab);
497	}
498
499	static void
500	module_exit(void)
501	{
502	mod_del_cmd(&cryptlink_msgtab);
503	}
504
505	struct module module_entry = {
506	.node = { NULL, NULL, NULL },
507	.name = NULL,
508	.version = "$Revision$",
509	.handle = NULL,
510	.modinit = module_init,
511	.modexit = module_exit,
512	.flags = 0
513	};
514	#endif