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 const char sasl_desc[] = "Provides SASL authentication support";
  45
  46 static void m_authenticate(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  47 static void me_sasl(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  48 static void me_mechlist(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
  49
  50 static void abort_sasl(struct Client *);
  51 static void abort_sasl_exit(hook_data_client_exit *);
  52
  53 static void advertise_sasl(struct Client *);
  54 static void advertise_sasl_exit(hook_data_client_exit *);
  55
  56 static unsigned int CLICAP_SASL = 0;
  57 static char mechlist_buf[BUFSIZE];
  58
  59 struct Message authenticate_msgtab = {
  60         "AUTHENTICATE", 0, 0, 0, 0,
  61         {{m_authenticate, 2}, {m_authenticate, 2}, mg_ignore, mg_ignore, mg_ignore, {m_authenticate, 2}}
  62 };
  63 struct Message sasl_msgtab = {
  64         "SASL", 0, 0, 0, 0,
  65         {mg_ignore, mg_ignore, mg_ignore, mg_ignore, {me_sasl, 5}, mg_ignore}
  66 };
  67 struct Message mechlist_msgtab = {
  68         "MECHLIST", 0, 0, 0, 0,
  69         {mg_ignore, mg_ignore, mg_ignore, mg_ignore, {me_mechlist, 2}, mg_ignore}
  70 };
  71
  72 mapi_clist_av1 sasl_clist[] = {
  73         &authenticate_msgtab, &sasl_msgtab, &mechlist_msgtab, NULL
  74 };
  75 mapi_hfn_list_av1 sasl_hfnlist[] = {
  76         { "new_local_user",     (hookfn) abort_sasl },
  77         { "client_exit",        (hookfn) abort_sasl_exit },
  78         { "new_remote_user",    (hookfn) advertise_sasl },
  79         { "client_exit",        (hookfn) advertise_sasl_exit },
  80         { NULL, NULL }
  81 };
  82
  83 static bool
  84 sasl_visible(struct Client *client_p)
  85 {
  86         struct Client *agent_p = NULL;
  87
  88         if (ConfigFileEntry.sasl_service)
  89                 agent_p = find_named_client(ConfigFileEntry.sasl_service);
  90
  91         return agent_p != NULL && IsService(agent_p);
  92 }
  93
  94 static const char *
  95 sasl_data(struct Client *client_p)
  96 {
  97         return *mechlist_buf != 0 ? mechlist_buf : NULL;
  98 }
  99
 100 static struct ClientCapability capdata_sasl = {
 101         .visible = sasl_visible,
 102         .data = sasl_data,
 103         .flags = CLICAP_FLAGS_STICKY,
 104 };
 105
 106 static int
 107 _modinit(void)
 108 {
 109         memset(mechlist_buf, 0, sizeof mechlist_buf);
 110         CLICAP_SASL = capability_put(cli_capindex, "sasl", &capdata_sasl);
 111         return 0;
 112 }
 113
 114 static void
 115 _moddeinit(void)
 116 {
 117         capability_orphan(cli_capindex, "sasl");
 118 }
 119
 120 DECLARE_MODULE_AV2(sasl, _modinit, _moddeinit, sasl_clist, NULL, sasl_hfnlist, NULL, NULL, sasl_desc);
 121
 122 static void
 123 m_authenticate(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 124         int parc, const char *parv[])
 125 {
 126         struct Client *agent_p = NULL;
 127         struct Client *saslserv_p = NULL;
 128
 129         /* They really should use CAP for their own sake. */
 130         if(!IsCapable(source_p, CLICAP_SASL))
 131                 return;
 132
 133         if (strlen(client_p->id) == 3)
 134         {
 135                 exit_client(client_p, client_p, client_p, "Mixing client and server protocol");
 136                 return;
 137         }
 138
 139         saslserv_p = find_named_client(ConfigFileEntry.sasl_service);
 140         if (saslserv_p == NULL || !IsService(saslserv_p))
 141         {
 142                 sendto_one(source_p, form_str(ERR_SASLABORTED), me.name, EmptyString(source_p->name) ? "*" : source_p->name);
 143                 return;
 144         }
 145
 146         if(source_p->localClient->sasl_complete)
 147         {
 148                 *source_p->localClient->sasl_agent = '\0';
 149                 source_p->localClient->sasl_complete = 0;
 150         }
 151
 152         if(strlen(parv[1]) > 400)
 153         {
 154                 sendto_one(source_p, form_str(ERR_SASLTOOLONG), me.name, EmptyString(source_p->name) ? "*" : source_p->name);
 155                 return;
 156         }
 157
 158         if(!*source_p->id)
 159         {
 160                 /* Allocate a UID. */
 161                 strcpy(source_p->id, generate_uid());
 162                 add_to_id_hash(source_p->id, source_p);
 163         }
 164
 165         if(*source_p->localClient->sasl_agent)
 166                 agent_p = find_id(source_p->localClient->sasl_agent);
 167
 168         if(agent_p == NULL)
 169         {
 170                 sendto_one(saslserv_p, ":%s ENCAP %s SASL %s %s H %s %s",
 171                                         me.id, saslserv_p->servptr->name, source_p->id, saslserv_p->id,
 172                                         source_p->host, source_p->sockhost);
 173
 174                 if (source_p->certfp != NULL)
 175                         sendto_one(saslserv_p, ":%s ENCAP %s SASL %s %s S %s %s",
 176                                                 me.id, saslserv_p->servptr->name, source_p->id, saslserv_p->id,
 177                                                 parv[1], source_p->certfp);
 178                 else
 179                         sendto_one(saslserv_p, ":%s ENCAP %s SASL %s %s S %s",
 180                                                 me.id, saslserv_p->servptr->name, source_p->id, saslserv_p->id,
 181                                                 parv[1]);
 182
 183                 rb_strlcpy(source_p->localClient->sasl_agent, saslserv_p->id, IDLEN);
 184         }
 185         else
 186                 sendto_one(agent_p, ":%s ENCAP %s SASL %s %s C %s",
 187                                 me.id, agent_p->servptr->name, source_p->id, agent_p->id,
 188                                 parv[1]);
 189         source_p->localClient->sasl_out++;
 190 }
 191
 192 static void
 193 me_sasl(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 194         int parc, const char *parv[])
 195 {
 196         struct Client *target_p, *agent_p;
 197
 198         /* Let propagate if not addressed to us, or if broadcast.
 199          * Only SASL agents can answer global requests.
 200          */
 201         if(strncmp(parv[2], me.id, 3))
 202                 return;
 203
 204         if((target_p = find_id(parv[2])) == NULL)
 205                 return;
 206
 207         if((agent_p = find_id(parv[1])) == NULL)
 208                 return;
 209
 210         if(source_p != agent_p->servptr) /* WTF?! */
 211                 return;
 212
 213         /* We only accept messages from SASL agents; these must have umode +S
 214          * (so the server must be listed in a service{} block).
 215          */
 216         if(!IsService(agent_p))
 217                 return;
 218
 219         /* Reject if someone has already answered. */
 220         if(*target_p->localClient->sasl_agent && strncmp(parv[1], target_p->localClient->sasl_agent, IDLEN))
 221                 return;
 222         else if(!*target_p->localClient->sasl_agent)
 223                 rb_strlcpy(target_p->localClient->sasl_agent, parv[1], IDLEN);
 224
 225         if(*parv[3] == 'C')
 226                 sendto_one(target_p, "AUTHENTICATE %s", parv[4]);
 227         else if(*parv[3] == 'D')
 228         {
 229                 if(*parv[4] == 'F')
 230                         sendto_one(target_p, form_str(ERR_SASLFAIL), me.name, EmptyString(target_p->name) ? "*" : target_p->name);
 231                 else if(*parv[4] == 'S') {
 232                         sendto_one(target_p, form_str(RPL_SASLSUCCESS), me.name, EmptyString(target_p->name) ? "*" : target_p->name);
 233                         target_p->localClient->sasl_complete = 1;
 234                         ServerStats.is_ssuc++;
 235                 }
 236                 *target_p->localClient->sasl_agent = '\0'; /* Blank the stored agent so someone else can answer */
 237         }
 238         else if(*parv[3] == 'M')
 239                 sendto_one(target_p, form_str(RPL_SASLMECHS), me.name, EmptyString(target_p->name) ? "*" : target_p->name, parv[4]);
 240 }
 241
 242 static void
 243 me_mechlist(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 244             int parc, const char *parv[])
 245 {
 246         rb_strlcpy(mechlist_buf, parv[1], sizeof mechlist_buf);
 247 }
 248
 249 /* If the client never finished authenticating but is
 250  * registering anyway, abort the exchange.
 251  */
 252 static void
 253 abort_sasl(struct Client *data)
 254 {
 255         if(data->localClient->sasl_out == 0 || data->localClient->sasl_complete)
 256                 return;
 257
 258         data->localClient->sasl_out = data->localClient->sasl_complete = 0;
 259         ServerStats.is_sbad++;
 260
 261         if(!IsClosing(data))
 262                 sendto_one(data, form_str(ERR_SASLABORTED), me.name, EmptyString(data->name) ? "*" : data->name);
 263
 264         if(*data->localClient->sasl_agent)
 265         {
 266                 struct Client *agent_p = find_id(data->localClient->sasl_agent);
 267                 if(agent_p)
 268                 {
 269                         sendto_one(agent_p, ":%s ENCAP %s SASL %s %s D A", me.id, agent_p->servptr->name,
 270                                         data->id, agent_p->id);
 271                         return;
 272                 }
 273         }
 274
 275         sendto_server(NULL, NULL, CAP_TS6|CAP_ENCAP, NOCAPS, ":%s ENCAP * SASL %s * D A", me.id,
 276                         data->id);
 277 }
 278
 279 static void
 280 abort_sasl_exit(hook_data_client_exit *data)
 281 {
 282         if (data->target->localClient)
 283                 abort_sasl(data->target);
 284 }
 285
 286 static void
 287 advertise_sasl(struct Client *client_p)
 288 {
 289         if (!ConfigFileEntry.sasl_service)
 290                 return;
 291
 292         if (irccmp(client_p->name, ConfigFileEntry.sasl_service))
 293                 return;
 294
 295         sendto_local_clients_with_capability(CLICAP_CAP_NOTIFY, ":%s CAP * NEW :sasl", me.name);
 296 }
 297
 298 static void
 299 advertise_sasl_exit(hook_data_client_exit *data)
 300 {
 301         if (!ConfigFileEntry.sasl_service)
 302                 return;
 303
 304         if (irccmp(data->target->name, ConfigFileEntry.sasl_service))
 305                 return;
 306
 307         sendto_local_clients_with_capability(CLICAP_CAP_NOTIFY, ":%s CAP * DEL :sasl", me.name);
 308 }