citadel/server/modules/listsub/serv_listsub.c

   1 // This module handles self-service subscription/unsubscription to mail lists.
   2 //
   3 // Copyright (c) 2002-2022 by the citadel.org team
   4 //
   5 // This program is open source software.  It runs great on the
   6 // Linux operating system (and probably elsewhere).  You can use,
   7 // copy, and run it under the terms of the GNU General Public
   8 // License version 3.
   9 //
  10 // This program is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14
  15 #include "../../sysdep.h"
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18 #include <stdio.h>
  19 #include <fcntl.h>
  20 #include <ctype.h>
  21 #include <signal.h>
  22 #include <pwd.h>
  23 #include <errno.h>
  24 #include <sys/types.h>
  25 #include <dirent.h>
  26 #include <time.h>
  27 #include <sys/wait.h>
  28 #include <string.h>
  29 #include <limits.h>
  30 #include <libcitadel.h>
  31 #include "../../citadel_defs.h"
  32 #include "../../server.h"
  33 #include "../../citserver.h"
  34 #include "../../support.h"
  35 #include "../../config.h"
  36 #include "../../user_ops.h"
  37 #include "../../database.h"
  38 #include "../../msgbase.h"
  39 #include "../../internet_addressing.h"
  40 #include "../../clientsocket.h"
  41 #include "../../ctdl_module.h"
  42
  43
  44 enum {                          // one of these gets passed to do_subscribe_or_unsubscribe() so it knows what we asked for
  45         UNSUBSCRIBE,
  46         SUBSCRIBE
  47 };
  48
  49
  50 // The confirmation token will be generated by combining the room name and email address with the host key,
  51 // and then generating a one-way hash of that string.  The hash is included as part of the confirmation link.
  52 void generate_confirmation_token(char *token_buf, size_t token_buf_len, char *roomname, char *emailaddr) {
  53         char string_to_hash[1024];
  54
  55         snprintf(string_to_hash, sizeof string_to_hash, "%s|%s|%s", roomname, emailaddr, CtdlGetConfigStr("host_key"));
  56         snprintf(token_buf, token_buf_len, "%lx",  FourHash(string_to_hash, strlen(string_to_hash)));
  57 }
  58
  59
  60 // This generates an email with a link the user clicks to confirm a list subscription.
  61 void send_subscribe_confirmation_email(char *roomname, char *emailaddr, char *url, char *confirmation_token) {
  62         // We need a URL-safe representation of the room name
  63         char urlroom[ROOMNAMELEN+10];
  64         urlesc(urlroom, sizeof(urlroom), roomname);
  65
  66         char from_address[1024];
  67         snprintf(from_address, sizeof from_address, "noreply@%s", CtdlGetConfigStr("c_fqdn"));
  68
  69         char emailtext[SIZ];
  70         snprintf(emailtext, sizeof emailtext,
  71                 "MIME-Version: 1.0\n"
  72                 "Content-Type: multipart/alternative; boundary=\"__ctdlmultipart__\"\n"
  73                 "\n"
  74                 "This is a multipart message in MIME format.\n"
  75                 "\n"
  76                 "--__ctdlmultipart__\n"
  77                 "Content-type: text/plain\n"
  78                 "\n"
  79                 "Someone (probably you) has submitted a request to subscribe\n"
  80                 "<%s> to the <%s> mailing list.\n"
  81                 "\n"
  82                 "Please go here to confirm this request:\n"
  83                 "%s?cmd=confirm_subscribe&email=%s&room=%s&token=%s\n"
  84                 "\n"
  85                 "If this request has been submitted in error and you do not\n"
  86                 "wish to receive the <%s> mailing list, simply do nothing,\n"
  87                 "and you will not receive any further mailings.\n"
  88                 "\n"
  89                 "--__ctdlmultipart__\n"
  90                 "Content-type: text/html\n"
  91                 "\n"
  92                 "<html><body><p>Someone (probably you) has submitted a request to subscribe "
  93                 "<strong>%s</strong> to the <strong>%s</strong> mailing list.</p>"
  94                 "<p>Please go here to confirm this request:</p>"
  95                 "<p><a href=\"%s?cmd=confirm_subscribe&email=%s&room=%s&token=%s\">"
  96                 "%s?cmd=confirm_subscribe&email=%s&room=%s&token=%s</a></p>"
  97                 "<p>If this request has been submitted in error and you do not "
  98                 "wish to receive the <strong>%s<strong> mailing list, simply do nothing, "
  99                 "and you will not receive any further mailings.</p>"
 100                 "</body></html>\n"
 101                 "\n"
 102                 "--__ctdlmultipart__--\n"
 103                 ,
 104                 emailaddr, roomname,
 105                 url, emailaddr, urlroom, confirmation_token,
 106                 roomname
 107                 ,
 108                 emailaddr, roomname,
 109                 url, emailaddr, urlroom, confirmation_token,
 110                 url, emailaddr, urlroom, confirmation_token,
 111                 roomname
 112         );
 113
 114         quickie_message("Citadel", from_address, emailaddr, NULL, emailtext, FMT_RFC822, "Please confirm your list subscription");
 115         cprintf("%d confirmation email sent\n", CIT_OK);
 116 }
 117
 118
 119 // This generates an email with a link the user clicks to confirm a list unsubscription.
 120 void send_unsubscribe_confirmation_email(char *roomname, char *emailaddr, char *url, char *confirmation_token) {
 121         // We need a URL-safe representation of the room name
 122         char urlroom[ROOMNAMELEN+10];
 123         urlesc(urlroom, sizeof(urlroom), roomname);
 124
 125         char from_address[1024];
 126         snprintf(from_address, sizeof from_address, "noreply@%s", CtdlGetConfigStr("c_fqdn"));
 127
 128         char emailtext[SIZ];
 129         snprintf(emailtext, sizeof emailtext,
 130                 "MIME-Version: 1.0\n"
 131                 "Content-Type: multipart/alternative; boundary=\"__ctdlmultipart__\"\n"
 132                 "\n"
 133                 "This is a multipart message in MIME format.\n"
 134                 "\n"
 135                 "--__ctdlmultipart__\n"
 136                 "Content-type: text/plain\n"
 137                 "\n"
 138                 "Someone (probably you) has submitted a request to unsubscribe\n"
 139                 "<%s> from the <%s> mailing list.\n"
 140                 "\n"
 141                 "Please go here to confirm this request:\n"
 142                 "%s?cmd=confirm_unsubscribe&email=%s&room=%s&token=%s\n"
 143                 "\n"
 144                 "If this request has been submitted in error and you still\n"
 145                 "wish to receive the <%s> mailing list, simply do nothing,\n"
 146                 "and you will remain subscribed.\n"
 147                 "\n"
 148                 "--__ctdlmultipart__\n"
 149                 "Content-type: text/html\n"
 150                 "\n"
 151                 "<html><body><p>Someone (probably you) has submitted a request to unsubscribe "
 152                 "<strong>%s</strong> from the <strong>%s</strong> mailing list.</p>"
 153                 "<p>Please go here to confirm this request:</p>"
 154                 "<p><a href=\"%s?cmd=confirm_unsubscribe&email=%s&room=%s&token=%s\">"
 155                 "%s?cmd=confirm_unsubscribe&email=%s&room=%s&token=%s</a></p>"
 156                 "<p>If this request has been submitted in error and you still "
 157                 "wish to receive the <strong>%s<strong> mailing list, simply do nothing, "
 158                 "and you will remain subscribed.</p>"
 159                 "</body></html>\n"
 160                 "\n"
 161                 "--__ctdlmultipart__--\n"
 162                 ,
 163                 emailaddr, roomname,
 164                 url, emailaddr, urlroom, confirmation_token,
 165                 roomname
 166                 ,
 167                 emailaddr, roomname,
 168                 url, emailaddr, urlroom, confirmation_token,
 169                 url, emailaddr, urlroom, confirmation_token,
 170                 roomname
 171         );
 172
 173         quickie_message("Citadel", from_address, emailaddr, NULL, emailtext, FMT_RFC822, "Please confirm your list unsubscription");
 174         cprintf("%d confirmation email sent\n", CIT_OK);
 175 }
 176
 177
 178 // Confirm a list subscription or unsubscription
 179 void do_confirm(int cmd, char *roomname, char *emailaddr, char *url, char *generated_token, char *supplied_token) {
 180         int i;
 181         char buf[1024];
 182         int config_lines = 0;
 183         char *oldnetconfig, *newnetconfig;
 184
 185         // During opt #1, the server generated a persistent confirmation token for the user+room combination.
 186         // Let's see if the user has supplied the same token during opt #2.
 187         if (strcmp(generated_token, supplied_token)) {
 188                 cprintf("%d This request could not be authenticated.\n", ERROR + PASSWORD_REQUIRED);
 189                 return;
 190         }
 191
 192         // If the generated token matches the supplied token, the request is authentic.  Do what it says.
 193
 194         // Load the room's network configuration...
 195         oldnetconfig = LoadRoomNetConfigFile(CC->room.QRnumber);
 196         if (!oldnetconfig) {
 197                 oldnetconfig = strdup("");
 198         }
 199
 200         // The new netconfig begins with an empty buffer...
 201         begin_critical_section(S_NETCONFIGS);
 202         newnetconfig = malloc(strlen(oldnetconfig) + 1024);
 203         newnetconfig[0] = 0;
 204
 205         // Load the config lines in one by one, skipping any that reference this subscriber.  Also remove blank lines.
 206         config_lines = num_tokens(oldnetconfig, '\n');
 207         for (i=0; i<config_lines; ++i) {
 208                 char buf_email[256];
 209                 extract_token(buf, oldnetconfig, i, '\n', sizeof buf);
 210                 extract_token(buf_email, buf, 1, '|', sizeof buf_email);
 211                 if ( !IsEmptyStr(buf) && (strcasecmp(buf_email, emailaddr)) ) {
 212                         sprintf(&newnetconfig[strlen(newnetconfig)], "%s\n", buf);
 213                 }
 214         }
 215
 216         // We have now removed all lines containing the subscriber's email address.  This deletes any pending requests.
 217         // If this was an unsubscribe operation, they're now gone from the list.
 218         // But if this was a subscribe operation, we now need to add them.
 219         if (cmd == SUBSCRIBE) {
 220                 sprintf(&newnetconfig[strlen(newnetconfig)], "listrecp|%s\n", emailaddr);
 221         }
 222
 223         // write it back to disk
 224         SaveRoomNetConfigFile(CC->room.QRnumber, newnetconfig);
 225         end_critical_section(S_NETCONFIGS);
 226         free(oldnetconfig);
 227         free(newnetconfig);
 228         cprintf("%d The pending request was confirmed.\n", CIT_OK);
 229 }
 230
 231
 232 // process subscribe/unsubscribe requests and confirmations
 233 void cmd_lsub(char *cmdbuf) {
 234         char cmd[20];
 235         char roomname[ROOMNAMELEN];
 236         char emailaddr[1024];
 237         char url[1024];
 238         char generated_token[128];
 239         char supplied_token[128];
 240
 241         extract_token(cmd, cmdbuf, 0, '|', sizeof cmd);                         // token 0 is the sub-command being sent
 242         extract_token(roomname, cmdbuf, 1, '|', sizeof roomname);               // token 1 is always a room name
 243         extract_token(emailaddr, cmdbuf, 2, '|', sizeof emailaddr);             // token 2 is the subscriber's email address
 244         extract_token(url, cmdbuf, 3, '|', sizeof url);                         // token 3 is the URL at which we subscribed
 245         extract_token(supplied_token, cmdbuf, 4, '|', sizeof supplied_token);   // token 4 is the token supplied by the caller
 246
 247         // First confirm that the caller is referencing a room that actually exists.
 248         if (CtdlGetRoom(&CC->room, roomname) != 0) {
 249                 cprintf("%d There is no list called '%s'\n", ERROR + ROOM_NOT_FOUND, roomname);
 250                 return;
 251         }
 252
 253         if ((CC->room.QRflags2 & QR2_SELFLIST) == 0) {
 254                 cprintf("%d '%s' does not accept subscribe/unsubscribe requests.\n", ERROR + ROOM_NOT_FOUND, roomname);
 255                 return;
 256         }
 257
 258         // Generate a confirmation token -- either to supply to the user for opt #1 or to compare for opt #2
 259         generate_confirmation_token(generated_token, sizeof generated_token, roomname, emailaddr);
 260
 261         // Now parse the command.
 262         if (!strcasecmp(cmd, "subscribe")) {
 263                 send_subscribe_confirmation_email(roomname, emailaddr, url, generated_token);
 264         }
 265
 266         else if (!strcasecmp(cmd, "unsubscribe")) {
 267                 send_unsubscribe_confirmation_email(roomname, emailaddr, url, generated_token);
 268         }
 269
 270         else if (!strcasecmp(cmd, "confirm_subscribe")) {
 271                 do_confirm(SUBSCRIBE, roomname, emailaddr, url, generated_token, supplied_token);
 272         }
 273
 274         else if (!strcasecmp(cmd, "confirm_unsubscribe")) {
 275                 do_confirm(UNSUBSCRIBE, roomname, emailaddr, url, generated_token, supplied_token);
 276         }
 277
 278         else {                                                                  // sorry man, I can't deal with that
 279                 cprintf("%d Invalid command '%s'\n", ERROR + ILLEGAL_VALUE, cmd);
 280         }
 281 }
 282
 283
 284 // Initialization function, called from modules_init.c
 285 char *ctdl_module_init_listsub(void) {
 286         if (!threading) {
 287                 CtdlRegisterProtoHook(cmd_lsub, "LSUB", "List subscribe/unsubscribe");
 288         }
 289
 290         /* return our module name for the log */
 291         return "listsub";
 292 }