modules/m_sasl.c

   1 /* modules/m_sasl.c
   2  *   Copyright (C) 2006 Michael Tharp <gxti@partiallystapled.com>
   3  *   Copyright (C) 2006 charybdis development team
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met:
   8  *
   9  * 1.Redistributions of source code must retain the above copyright notice,
  10  *   this list of conditions and the following disclaimer.
  11  * 2.Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * 3.The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27  * POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include "stdinc.h"
  31
  32 #include "client.h"
  33 #include "hash.h"
  34 #include "send.h"
  35 #include "msg.h"
  36 #include "modules.h"
  37 #include "numeric.h"
  38 #include "s_serv.h"
  39 #include "s_stats.h"
  40 #include "string.h"
  41 #include "s_newconf.h"
  42 #include "s_conf.h"
  43
  44 static int m_authenticate(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  45 static int me_sasl(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  46 static int me_mechlist(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  47 static const char sasl_desc[] = "Provides SASL authentication support";
  48
  49 static void abort_sasl(struct Client *);
  50 static void abort_sasl_exit(hook_data_client_exit *);
  51
  52 static void advertise_sasl(struct Client *);
  53 static void advertise_sasl_exit(hook_data_client_exit *);
  54
  55 static unsigned int CLICAP_SASL = 0;
  56 static char mechlist_buf[BUFSIZE];
  57
  58 struct Message authenticate_msgtab = {
  59         "AUTHENTICATE", 0, 0, 0, 0,
  60         {{m_authenticate, 2}, {m_authenticate, 2}, mg_ignore, mg_ignore, mg_ignore, {m_authenticate, 2}}
  61 };
  62 struct Message sasl_msgtab = {
  63         "SASL", 0, 0, 0, 0,
  64         {mg_ignore, mg_ignore, mg_ignore, mg_ignore, {me_sasl, 5}, mg_ignore}
  65 };
  66 struct Message mechlist_msgtab = {
  67         "MECHLIST", 0, 0, 0, 0,
  68         {mg_ignore, mg_ignore, mg_ignore, mg_ignore, {me_mechlist, 2}, mg_ignore}
  69 };
  70
  71 mapi_clist_av1 sasl_clist[] = {
  72         &authenticate_msgtab, &sasl_msgtab, &mechlist_msgtab, NULL
  73 };
  74 mapi_hfn_list_av1 sasl_hfnlist[] = {
  75         { "new_local_user",     (hookfn) abort_sasl },
  76         { "client_exit",        (hookfn) abort_sasl_exit },
  77         { "new_remote_user",    (hookfn) advertise_sasl },
  78         { "client_exit",        (hookfn) advertise_sasl_exit },
  79         { NULL, NULL }
  80 };
  81
  82 static int
  83 sasl_visible(struct Client *client_p)
  84 {
  85         struct Client *agent_p = NULL;
  86
  87         if (ConfigFileEntry.sasl_service)
  88                 agent_p = find_named_client(ConfigFileEntry.sasl_service);
  89
  90         return agent_p != NULL && IsService(agent_p);
  91 }
  92
  93 static const char *
  94 sasl_data(struct Client *client_p)
  95 {
  96         return *mechlist_buf != 0 ? mechlist_buf : NULL;
  97 }
  98
  99 static struct ClientCapability capdata_sasl = {
 100         .visible = sasl_visible,
 101         .data = sasl_data,
 102         .flags = CLICAP_FLAGS_STICKY,
 103 };
 104
 105 static int
 106 _modinit(void)
 107 {
 108         memset(mechlist_buf, 0, sizeof mechlist_buf);
 109         CLICAP_SASL = capability_put(cli_capindex, "sasl", &capdata_sasl);
 110         return 0;
 111 }
 112
 113 static void
 114 _moddeinit(void)
 115 {
 116         capability_orphan(cli_capindex, "sasl");
 117 }
 118
 119 DECLARE_MODULE_AV2(sasl, _modinit, _moddeinit, sasl_clist, NULL, sasl_hfnlist, NULL, NULL, sasl_desc);
 120
 121 static int
 122 m_authenticate(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 123         int parc, const char *parv[])
 124 {
 125         struct Client *agent_p = NULL;
 126         struct Client *saslserv_p = NULL;
 127
 128         /* They really should use CAP for their own sake. */
 129         if(!IsCapable(source_p, CLICAP_SASL))
 130                 return 0;
 131
 132         if (strlen(client_p->id) == 3)
 133         {
 134                 exit_client(client_p, client_p, client_p, "Mixing client and server protocol");
 135                 return 0;
 136         }
 137
 138         saslserv_p = find_named_client(ConfigFileEntry.sasl_service);
 139         if (saslserv_p == NULL || !IsService(saslserv_p))
 140         {
 141                 sendto_one(source_p, form_str(ERR_SASLABORTED), me.name, EmptyString(source_p->name) ? "*" : source_p->name);
 142                 return 0;
 143         }
 144
 145         if(source_p->localClient->sasl_complete)
 146         {
 147                 *source_p->localClient->sasl_agent = '\0';
 148                 source_p->localClient->sasl_complete = 0;
 149         }
 150
 151         if(strlen(parv[1]) > 400)
 152         {
 153                 sendto_one(source_p, form_str(ERR_SASLTOOLONG), me.name, EmptyString(source_p->name) ? "*" : source_p->name);
 154                 return 0;
 155         }
 156
 157         if(!*source_p->id)
 158         {
 159                 /* Allocate a UID. */
 160                 strcpy(source_p->id, generate_uid());
 161                 add_to_id_hash(source_p->id, source_p);
 162         }
 163
 164         if(*source_p->localClient->sasl_agent)
 165                 agent_p = find_id(source_p->localClient->sasl_agent);
 166
 167         if(agent_p == NULL)
 168         {
 169                 sendto_one(saslserv_p, ":%s ENCAP %s SASL %s %s H %s %s",
 170                                         me.id, saslserv_p->servptr->name, source_p->id, saslserv_p->id,
 171                                         source_p->host, source_p->sockhost);
 172
 173                 if (source_p->certfp != NULL)
 174                         sendto_one(saslserv_p, ":%s ENCAP %s SASL %s %s S %s %s",
 175                                                 me.id, saslserv_p->servptr->name, source_p->id, saslserv_p->id,
 176                                                 parv[1], source_p->certfp);
 177                 else
 178                         sendto_one(saslserv_p, ":%s ENCAP %s SASL %s %s S %s",
 179                                                 me.id, saslserv_p->servptr->name, source_p->id, saslserv_p->id,
 180                                                 parv[1]);
 181
 182                 rb_strlcpy(source_p->localClient->sasl_agent, saslserv_p->id, IDLEN);
 183         }
 184         else
 185                 sendto_one(agent_p, ":%s ENCAP %s SASL %s %s C %s",
 186                                 me.id, agent_p->servptr->name, source_p->id, agent_p->id,
 187                                 parv[1]);
 188         source_p->localClient->sasl_out++;
 189
 190         return 0;
 191 }
 192
 193 static int
 194 me_sasl(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 195         int parc, const char *parv[])
 196 {
 197         struct Client *target_p, *agent_p;
 198
 199         /* Let propagate if not addressed to us, or if broadcast.
 200          * Only SASL agents can answer global requests.
 201          */
 202         if(strncmp(parv[2], me.id, 3))
 203                 return 0;
 204
 205         if((target_p = find_id(parv[2])) == NULL)
 206                 return 0;
 207
 208         if((agent_p = find_id(parv[1])) == NULL)
 209                 return 0;
 210
 211         if(source_p != agent_p->servptr) /* WTF?! */
 212                 return 0;
 213
 214         /* We only accept messages from SASL agents; these must have umode +S
 215          * (so the server must be listed in a service{} block).
 216          */
 217         if(!IsService(agent_p))
 218                 return 0;
 219
 220         /* Reject if someone has already answered. */
 221         if(*target_p->localClient->sasl_agent && strncmp(parv[1], target_p->localClient->sasl_agent, IDLEN))
 222                 return 0;
 223         else if(!*target_p->localClient->sasl_agent)
 224                 rb_strlcpy(target_p->localClient->sasl_agent, parv[1], IDLEN);
 225
 226         if(*parv[3] == 'C')
 227                 sendto_one(target_p, "AUTHENTICATE %s", parv[4]);
 228         else if(*parv[3] == 'D')
 229         {
 230                 if(*parv[4] == 'F')
 231                         sendto_one(target_p, form_str(ERR_SASLFAIL), me.name, EmptyString(target_p->name) ? "*" : target_p->name);
 232                 else if(*parv[4] == 'S') {
 233                         sendto_one(target_p, form_str(RPL_SASLSUCCESS), me.name, EmptyString(target_p->name) ? "*" : target_p->name);
 234                         target_p->localClient->sasl_complete = 1;
 235                         ServerStats.is_ssuc++;
 236                 }
 237                 *target_p->localClient->sasl_agent = '\0'; /* Blank the stored agent so someone else can answer */
 238         }
 239         else if(*parv[3] == 'M')
 240                 sendto_one(target_p, form_str(RPL_SASLMECHS), me.name, EmptyString(target_p->name) ? "*" : target_p->name, parv[4]);
 241
 242         return 0;
 243 }
 244
 245 static int
 246 me_mechlist(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 247             int parc, const char *parv[])
 248 {
 249         rb_strlcpy(mechlist_buf, parv[1], sizeof mechlist_buf);
 250
 251         return 0;
 252 }
 253
 254 /* If the client never finished authenticating but is
 255  * registering anyway, abort the exchange.
 256  */
 257 static void
 258 abort_sasl(struct Client *data)
 259 {
 260         if(data->localClient->sasl_out == 0 || data->localClient->sasl_complete)
 261                 return;
 262
 263         data->localClient->sasl_out = data->localClient->sasl_complete = 0;
 264         ServerStats.is_sbad++;
 265
 266         if(!IsClosing(data))
 267                 sendto_one(data, form_str(ERR_SASLABORTED), me.name, EmptyString(data->name) ? "*" : data->name);
 268
 269         if(*data->localClient->sasl_agent)
 270         {
 271                 struct Client *agent_p = find_id(data->localClient->sasl_agent);
 272                 if(agent_p)
 273                 {
 274                         sendto_one(agent_p, ":%s ENCAP %s SASL %s %s D A", me.id, agent_p->servptr->name,
 275                                         data->id, agent_p->id);
 276                         return;
 277                 }
 278         }
 279
 280         sendto_server(NULL, NULL, CAP_TS6|CAP_ENCAP, NOCAPS, ":%s ENCAP * SASL %s * D A", me.id,
 281                         data->id);
 282 }
 283
 284 static void
 285 abort_sasl_exit(hook_data_client_exit *data)
 286 {
 287         if (data->target->localClient)
 288                 abort_sasl(data->target);
 289 }
 290
 291 static void
 292 advertise_sasl(struct Client *client_p)
 293 {
 294         if (!ConfigFileEntry.sasl_service)
 295                 return;
 296
 297         if (irccmp(client_p->name, ConfigFileEntry.sasl_service))
 298                 return;
 299
 300         sendto_local_clients_with_capability(CLICAP_CAP_NOTIFY, ":%s CAP * NEW :sasl", me.name);
 301 }
 302
 303 static void
 304 advertise_sasl_exit(hook_data_client_exit *data)
 305 {
 306         if (!ConfigFileEntry.sasl_service)
 307                 return;
 308
 309         if (irccmp(data->target->name, ConfigFileEntry.sasl_service))
 310                 return;
 311
 312         sendto_local_clients_with_capability(CLICAP_CAP_NOTIFY, ":%s CAP * DEL :sasl", me.name);
 313 }