ircd-hybrid-7.2/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"
#include "handlers.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 "msg.h"
#include "parse.h"
#include "irc_string.h"  /* strncpy_irc */
#include "tools.h"
#include "memory.h"
#include "common.h"      /* TRUE bleah */
#include "event.h"
#include "hash.h"        /* add_to_client_hash_table */
#include "list.h"        /* make_server */
#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 int bogus_host(char *host);
static char *parse_cryptserv_args(struct Client *client_p,
                                  char *parv[], int parc, char *info,
                                  char *key);

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

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

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 */
  { (char *)0,  (void (*)())0,  }
};

#ifndef STATIC_MODULES
void 
_modinit(void)
{
  mod_add_cmd(&cryptlink_msgtab);
}

void
_moddeinit(void)
{
  mod_del_cmd(&cryptlink_msgtab);
}

const char *_version = "$Revision$";
#endif


/* 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 (bogus_host(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 = 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);
}

/* bogus_host()
 *
 * inputs       - hostname
 * output       - 1 if a bogus hostname input, 0 if its valid
 * side effects - none
 */
static int
bogus_host(char *host)
{
  unsigned int length = 0;
  unsigned int dots   = 0;
  char *s = host;

  for (; *s; s++)
  {
    if (!IsServChar(*s))
      return(1);

    ++length;

    if ('.' == *s)
      ++dots;
  }

  return(!dots || length > HOSTLEN);
}
Revision:	896
Committed:	Sat Nov 3 08:54:09 2007 UTC (18 years, 11 months ago) by michael
Content type:	text/x-csrc
File size:	14152 byte(s)
Log Message:	- Killed s_stats.c
#	User	Rev	Content
1	adx	30	/*
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	knight	31	* $Id$
23	adx	30	*/
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			#include "handlers.h"
34			#include "client.h" /* client struct */
35			#include "ircd.h" /* me */
36			#include "modules.h"
37			#include "numeric.h" /* ERR_xxx */
38			#include "send.h" /* sendto_one */
39			#include <openssl/rsa.h> /* rsa.h is implicit when building this */
40			#include "rsa.h"
41			#include "msg.h"
42			#include "parse.h"
43			#include "irc_string.h" /* strncpy_irc */
44			#include "tools.h"
45			#include "memory.h"
46			#include "common.h" /* TRUE bleah */
47			#include "event.h"
48			#include "hash.h" /* add_to_client_hash_table */
49			#include "list.h" /* make_server */
50			#include "s_conf.h" /* struct AccessItem */
51			#include "s_log.h" /* log level defines */
52			#include "s_serv.h" /* server_estab, check_server, my_name_for_link */
53			#include "motd.h"
54
55			static int bogus_host(char *host);
56			static char parse_cryptserv_args(struct Client client_p,
57			char parv[], int parc, char info,
58			char *key);
59
60			static void mr_cryptlink(struct Client , struct Client , int, char **);
61			static void cryptlink_serv(struct Client , struct Client , int, char **);
62			static void cryptlink_auth(struct Client , struct Client , int, char **);
63
64			struct Message cryptlink_msgtab = {
65			"CRYPTLINK", 0, 0, 4, 0, MFLG_SLOW \| MFLG_UNREG, 0,
66			{mr_cryptlink, m_ignore, m_error, m_ignore, m_ignore, m_ignore}
67			};
68
69			struct CryptLinkStruct
70			{
71			const char cmd; / CRYPTLINK <command> to match */
72			void (handler)(); / Function to call */
73			};
74
75			static struct CryptLinkStruct cryptlink_cmd_table[] =
76			{
77			/* command function */
78			{ "AUTH", cryptlink_auth, },
79			{ "SERV", cryptlink_serv, },
80			/* End of table */
81			{ (char )0, (void ()())0, }
82			};
83
84			#ifndef STATIC_MODULES
85			void
86			_modinit(void)
87			{
88			mod_add_cmd(&cryptlink_msgtab);
89			}
90
91			void
92			_moddeinit(void)
93			{
94			mod_del_cmd(&cryptlink_msgtab);
95			}
96
97	knight	31	const char *_version = "$Revision$";
98	adx	30	#endif
99
100
101			/* mr_cryptlink - CRYPTLINK message handler
102			* parv[0] == CRYPTLINK
103			* parv[1] = command (SERV, AUTH)
104			* parv[2] = Parameters specific to each command (parv[1]):
105			* SERV - parc must be >= 5
106			* parv[0] == CRYPTLINK
107			* parv[1] == SERV
108			* parv[2] == server name
109			* parv[3] == keyphrase
110			* parv[4] == :server info (M-line)
111			* AUTH - parc must be >= 4
112			* parv[0] == CRYPTLINK
113			* parv[1] == AUTH
114			* parv[2] == cipher (eg. BF/168)
115			* parv[3] == keyphrase
116			*/
117			static void
118			mr_cryptlink(struct Client client_p, struct Client source_p,
119			int parc, char *parv[])
120			{
121			int i;
122
123			for (i = 0; cryptlink_cmd_table[i].handler; i++)
124			{
125			/* Traverse through the command table */
126			if (!irccmp(cryptlink_cmd_table[i].cmd, parv[1]))
127			{
128			/*
129			* Match found. Time to execute the function
130			*/
131			cryptlink_cmd_table[i].handler(client_p, source_p, parc, parv);
132			}
133			}
134			}
135
136			/*
137			* cryptlink_auth - CRYPTLINK AUTH message handler
138			* parv[1] = secret key
139			*/
140			static void
141			cryptlink_auth(struct Client client_p, struct Client source_p,
142			int parc, char *parv[])
143			{
144			struct EncCapability *ecap;
145			struct ConfItem *conf;
146			struct AccessItem *aconf;
147			int enc_len;
148			int len;
149			unsigned char *enc;
150			unsigned char *key;
151
152			if (parc < 4)
153			{
154			cryptlink_error(client_p, "AUTH", "Invalid params",
155			"CRYPTLINK AUTH - Invalid params");
156			return;
157			}
158
159			if (!IsWaitAuth(client_p))
160			return;
161
162			for (ecap = CipherTable; ecap->name; ecap++)
163			{
164			if ((!irccmp(ecap->name, parv[2])) &&
165			(IsCapableEnc(client_p, ecap->cap)))
166			{
167			client_p->localClient->in_cipher = ecap;
168			break;
169			}
170			}
171
172			if (client_p->localClient->in_cipher == NULL)
173			{
174			cryptlink_error(client_p, "AUTH", "Invalid cipher", "Invalid cipher");
175			return;
176			}
177
178			if (!(enc_len = unbase64_block(&enc, parv[3], strlen(parv[3]))))
179			{
180			cryptlink_error(client_p, "AUTH",
181			"Could not base64 decode response",
182			"Malformed CRYPTLINK AUTH reply");
183			return;
184			}
185
186			if (verify_private_key() == -1)
187			{
188			sendto_realops_flags(UMODE_ALL, L_ADMIN,
189			"verify_private_key() returned -1. Check log for information.");
190			}
191
192			key = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
193			len = RSA_private_decrypt(enc_len, (unsigned char )enc,(unsigned char )key,
194			ServerInfo.rsa_private_key,
195			RSA_PKCS1_PADDING);
196
197			if (len < client_p->localClient->in_cipher->keylen)
198			{
199			report_crypto_errors();
200			if (len < 0)
201			{
202			cryptlink_error(client_p, "AUTH",
203			"Decryption failed",
204			"Malformed CRYPTLINK AUTH reply");
205			}
206			else
207			{
208			cryptlink_error(client_p, "AUTH",
209			"Not enough random data sent",
210			"Malformed CRYPTLINK AUTH reply");
211			}
212			MyFree(enc);
213			MyFree(key);
214			return;
215			}
216
217			if (memcmp(key, client_p->localClient->in_key,
218			client_p->localClient->in_cipher->keylen) != 0)
219			{
220			cryptlink_error(client_p, "AUTH",
221			"Unauthorized server connection attempt",
222			"Malformed CRYPTLINK AUTH reply");
223			return;
224			}
225
226			conf = find_conf_name(&client_p->localClient->confs,
227			client_p->name, SERVER_TYPE);
228
229			if (conf == NULL)
230			{
231			cryptlink_error(client_p, "AUTH",
232			"Lost C-line for server",
233			"Lost C-line");
234			return;
235			}
236
237			aconf = (struct AccessItem *)map_to_conf(conf);
238
239			if (!(client_p->localClient->out_cipher \|\|
240			(client_p->localClient->out_cipher = check_cipher(client_p, aconf))))
241			{
242			cryptlink_error(client_p, "AUTH",
243			"Couldn't find compatible cipher",
244			"Couldn't find compatible cipher");
245			return;
246			}
247
248			/* set hopcount */
249			client_p->hopcount = 1;
250
251			SetCryptIn(client_p);
252			ClearWaitAuth(client_p);
253			server_estab(client_p);
254			}
255
256			/*
257			* cryptlink_serv - CRYPTLINK SERV message handler
258			* parv[0] == CRYPTLINK
259			* parv[1] == SERV
260			* parv[2] == server name
261			* parv[3] == keyphrase
262			* parv[4] == :server info (M-line)
263			*/
264			static void
265			cryptlink_serv(struct Client client_p, struct Client source_p,
266			int parc, char *parv[])
267			{
268			char info[REALLEN + 1];
269			char *name;
270			struct Client *target_p;
271			char *key = client_p->localClient->out_key;
272			unsigned char *b64_key;
273			struct ConfItem *conf;
274			struct AccessItem *aconf;
275			char *encrypted;
276			const char *p;
277			int enc_len;
278
279			/*
280			if (client_p->name[0] != 0)
281			return;
282			*/
283
284			if ((parc < 5) \|\| (*parv[4] == '\0'))
285			{
286			cryptlink_error(client_p, "SERV", "Invalid params",
287			"CRYPTLINK SERV - Invalid params");
288			return;
289			}
290
291			if ((name = parse_cryptserv_args(client_p, parv, parc, info, key)) == NULL)
292			{
293			cryptlink_error(client_p, "SERV", "Invalid params",
294			"CRYPTLINK SERV - Invalid params");
295			return;
296			}
297
298			/* CRYPTLINK SERV support => TS support */
299			client_p->tsinfo = TS_DOESTS;
300
301			if (bogus_host(name))
302			{
303			exit_client(client_p, client_p, "Bogus server name");
304			return;
305			}
306
307			/* Now we just have to call check_server and everything should be
308			* checked for us... -A1kmm. */
309			switch (check_server(name, client_p, CHECK_SERVER_CRYPTLINK))
310			{
311			case -1:
312			if (ConfigFileEntry.warn_no_nline)
313			{
314			cryptlink_error(client_p, "SERV",
315			"Unauthorized server connection attempt: No entry for server",
316			NULL);
317			}
318			exit_client(client_p, client_p, "Invalid server name");
319			return;
320			break;
321			case -2:
322			cryptlink_error(client_p, "SERV",
323			"Unauthorized server connection attempt: CRYPTLINK not "
324			"enabled on remote server",
325			"CRYPTLINK not enabled");
326			return;
327			break;
328			case -3:
329			cryptlink_error(client_p, "SERV",
330			"Unauthorized server connection attempt: Invalid host",
331			"Invalid host");
332			return;
333			break;
334			}
335
336			if ((target_p = find_server(name)))
337			{
338			/*
339			* This link is trying feed me a server that I already have
340			* access through another path -- multiple paths not accepted
341			* currently, kill this link immediately!!
342			*
343			* Rather than KILL the link which introduced it, KILL the
344			* youngest of the two links. -avalon
345			*
346			* Definitely don't do that here. This is from an unregistered
347			* connect - A1kmm.
348			*/
349			cryptlink_error(client_p, "SERV",
350			"Attempt to re-introduce existing server",
351			"Server Exists");
352			return;
353			}
354
355			conf = find_conf_name(&client_p->localClient->confs,
356			name, SERVER_TYPE);
357			if (conf == NULL)
358			{
359			cryptlink_error(client_p, "AUTH",
360			"Lost C-line for server",
361			"Lost C-line" );
362			return;
363			}
364
365			/*
366			* if we are connecting (Handshake), we already have the name from the
367			* connect {} block in client_p->name
368			*/
369			strlcpy(client_p->name, name, sizeof(client_p->name));
370
371			p = info;
372
373			if (!strncmp(info, "(H)", 3))
374			{
375			SetHidden(client_p);
376
377			if ((p = strchr(info, ' ')) != NULL)
378			{
379			p++;
380			if (*p == '\0')
381			p = "(Unknown Location)";
382			}
383			else
384			p = "(Unknown Location)";
385			}
386
387			strlcpy(client_p->info, p, sizeof(client_p->info));
388			client_p->hopcount = 0;
389
390			aconf = (struct AccessItem *)map_to_conf(conf);
391
392			if (!(client_p->localClient->out_cipher \|\|
393			(client_p->localClient->out_cipher = check_cipher(client_p, aconf))))
394			{
395			cryptlink_error(client_p, "AUTH",
396			"Couldn't find compatible cipher",
397			"Couldn't find compatible cipher");
398			return;
399			}
400
401			encrypted = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
402			enc_len = RSA_public_encrypt(client_p->localClient->out_cipher->keylen,
403			(unsigned char *)key,
404			(unsigned char *)encrypted,
405			aconf->rsa_public_key,
406			RSA_PKCS1_PADDING);
407
408			if (enc_len <= 0)
409			{
410			report_crypto_errors();
411			MyFree(encrypted);
412			cryptlink_error(client_p, "AUTH",
413			"Couldn't encrypt data",
414			"Couldn't encrypt data");
415			return;
416			}
417
418			base64_block(&b64_key, encrypted, enc_len);
419
420			MyFree(encrypted);
421
422			if (!IsWaitAuth(client_p))
423			cryptlink_init(client_p, conf, NULL);
424
425			sendto_one(client_p, "CRYPTLINK AUTH %s %s",
426			client_p->localClient->out_cipher->name,
427			b64_key);
428
429			/* needed for old servers that can't shove data back into slink */
430			send_queued_write(client_p);
431
432			SetCryptOut(client_p);
433			MyFree(b64_key);
434			}
435
436			/* parse_cryptserv_args()
437			*
438			* inputs - parv parameters
439			* - parc count
440			* - info string (to be filled in by this routine)
441			* - key (to be filled in by this routine)
442			* output - NULL if invalid params, server name otherwise
443			* side effects - parv[2] is trimmed to HOSTLEN size if needed.
444			*/
445			static char *
446			parse_cryptserv_args(struct Client client_p, char parv[],
447			int parc, char info, char key)
448			{
449			char *name;
450			unsigned char tmp, out;
451			int len;
452			int decoded_len;
453
454			info[0] = '\0';
455
456			name = parv[2];
457
458			/* parv[2] contains encrypted auth data */
459			if (!(decoded_len = unbase64_block(&tmp, parv[3],
460			strlen(parv[3]))))
461			{
462			cryptlink_error(client_p, "SERV",
463			"Couldn't base64 decode data",
464			NULL);
465			return(NULL);
466			}
467
468			if (verify_private_key() == -1)
469			{
470			sendto_realops_flags(UMODE_ALL, L_ADMIN,
471			"verify_private_key() returned -1. Check log for information.");
472			}
473
474			if (ServerInfo.rsa_private_key == NULL)
475			{
476			cryptlink_error(client_p, "SERV", "No local private key found", NULL);
477			return(NULL);
478			}
479
480			out = MyMalloc(RSA_size(ServerInfo.rsa_private_key));
481			len = RSA_private_decrypt(decoded_len, tmp, out,
482			ServerInfo.rsa_private_key,
483			RSA_PKCS1_PADDING);
484
485			MyFree(tmp);
486
487			if (len < CIPHERKEYLEN)
488			{
489			report_crypto_errors();
490			if (len < 0)
491			{
492			cryptlink_error(client_p, "AUTH", "Decryption failed", NULL);
493			}
494			else
495			{
496			cryptlink_error(client_p, "AUTH", "Not enough random data sent", NULL);
497			}
498			MyFree(out);
499			return(NULL);
500			}
501
502			memcpy(key, out, CIPHERKEYLEN);
503			MyFree(out);
504
505			strlcpy(info, parv[4], REALLEN + 1);
506
507			if (strlen(name) > HOSTLEN)
508			name[HOSTLEN] = '\0';
509
510			return(name);
511			}
512
513			/* bogus_host()
514			*
515			* inputs - hostname
516			* output - 1 if a bogus hostname input, 0 if its valid
517			* side effects - none
518			*/
519			static int
520			bogus_host(char *host)
521			{
522			unsigned int length = 0;
523			unsigned int dots = 0;
524			char *s = host;
525
526			for (; *s; s++)
527			{
528			if (!IsServChar(*s))
529			return(1);
530
531			++length;
532
533			if ('.' == *s)
534			++dots;
535			}
536
537			return(!dots \|\| length > HOSTLEN);
538			}