mirror of https://github.com/pissnet/pissircd.git
412 lines
11 KiB
C
412 lines
11 KiB
C
/*
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* IRC - Internet Relay Chat, src/modules/cloak_sha256.c
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* (C) 2004-2021 Bram Matthys and The UnrealIRCd Team
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*
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* See file AUTHORS in IRC package for additional names of
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* the programmers.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 1, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include "unrealircd.h"
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static char *cloak_key1 = NULL, *cloak_key2 = NULL, *cloak_key3 = NULL;
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static char cloak_checksum[64];
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static int nokeys = 1;
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int CLOAK_IP_ONLY = 0;
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#undef KEY1
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#undef KEY2
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#undef KEY3
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#define KEY1 cloak_key1
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#define KEY2 cloak_key2
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#define KEY3 cloak_key3
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#define SHA256_HASH_SIZE (256/8)
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char *hidehost(Client *client, char *host);
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char *cloakcsum();
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int cloak_config_test(ConfigFile *, ConfigEntry *, int, int *);
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int cloak_config_run(ConfigFile *, ConfigEntry *, int);
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int cloak_config_posttest(int *);
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static char *hidehost_ipv4(char *host);
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static char *hidehost_ipv6(char *host);
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static char *hidehost_normalhost(char *host);
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static inline unsigned int downsample(char *i);
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ModuleHeader MOD_HEADER = {
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"cloak_sha256",
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"1.0",
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"Cloaking module (SHA256)",
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"UnrealIRCd Team",
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"unrealircd-6",
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};
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MOD_TEST()
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{
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if (!CallbackAddString(modinfo->handle, CALLBACKTYPE_CLOAK_KEY_CHECKSUM, cloakcsum))
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{
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unreal_log(ULOG_ERROR, "config", "CLOAK_MODULE_DUPLICATE", NULL,
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"cloak_sha256: Error while trying to install callback.\n"
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"Maybe you have multiple cloaking modules loaded? You can only load one!");
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return MOD_FAILED;
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}
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if (!CallbackAddString(modinfo->handle, CALLBACKTYPE_CLOAK_EX, hidehost))
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{
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config_error("cloak_sha256: Error while trying to install cloaking callback!");
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return MOD_FAILED;
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}
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HookAdd(modinfo->handle, HOOKTYPE_CONFIGTEST, 0, cloak_config_test);
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HookAdd(modinfo->handle, HOOKTYPE_CONFIGPOSTTEST, 0, cloak_config_posttest);
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return MOD_SUCCESS;
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}
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MOD_INIT()
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{
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MARK_AS_OFFICIAL_MODULE(modinfo);
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HookAdd(modinfo->handle, HOOKTYPE_CONFIGRUN, 0, cloak_config_run);
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return MOD_SUCCESS;
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}
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MOD_LOAD()
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{
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return MOD_SUCCESS;
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}
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MOD_UNLOAD()
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{
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if (cloak_key1)
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{
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safe_free(cloak_key1);
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safe_free(cloak_key2);
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safe_free(cloak_key3);
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}
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return MOD_SUCCESS;
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}
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static int check_badrandomness(char *key)
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{
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char gotlowcase=0, gotupcase=0, gotdigit=0;
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char *p;
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for (p=key; *p; p++)
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{
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if (islower(*p))
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gotlowcase = 1;
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else if (isupper(*p))
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gotupcase = 1;
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else if (isdigit(*p))
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gotdigit = 1;
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}
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if (gotlowcase && gotupcase && gotdigit)
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return 0;
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return 1;
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}
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int cloak_config_test(ConfigFile *cf, ConfigEntry *ce, int type, int *errs)
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{
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ConfigEntry *cep;
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int keycnt = 0, errors = 0;
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char *keys[3];
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if (type == CONFIG_SET)
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{
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/* set::cloak-method */
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if (!ce || !ce->name || strcmp(ce->name, "cloak-method"))
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return 0;
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if (!ce->value)
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{
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config_error("%s:%i: set::cloak-method: no method specified. The only supported methods are: 'ip' and 'host'",
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ce->file->filename, ce->line_number);
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errors++;
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} else
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if (strcmp(ce->value, "ip") && strcmp(ce->value, "host"))
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{
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config_error("%s:%i: set::cloak-method: unknown method '%s'. The only supported methods are: 'ip' and 'host'",
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ce->file->filename, ce->line_number, ce->value);
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errors++;
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}
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*errs = errors;
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return errors ? -1 : 1;
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}
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if (type != CONFIG_CLOAKKEYS)
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return 0;
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nokeys = 0;
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for (cep = ce->items; cep; cep = cep->next)
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{
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keycnt++;
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if (check_badrandomness(cep->name))
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{
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config_error("%s:%i: set::cloak-keys: (key %d) Keys should be mixed a-zA-Z0-9, "
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"like \"a2JO6fh3Q6w4oN3s7\"", cep->file->filename, cep->line_number, keycnt);
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errors++;
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}
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if (strlen(cep->name) < 80)
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{
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config_error("%s:%i: set::cloak-keys: (key %d) Each key should be at least 80 characters",
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cep->file->filename, cep->line_number, keycnt);
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errors++;
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}
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if (strlen(cep->name) > 1000)
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{
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config_error("%s:%i: set::cloak-keys: (key %d) Each key should be less than 1000 characters",
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cep->file->filename, cep->line_number, keycnt);
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errors++;
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}
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if (keycnt < 4)
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keys[keycnt-1] = cep->name;
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}
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if (keycnt != 3)
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{
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config_error("%s:%i: set::cloak-keys: we want 3 values, not %i!",
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ce->file->filename, ce->line_number, keycnt);
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errors++;
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}
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if ((keycnt == 3) && (!strcmp(keys[0], keys[1]) || !strcmp(keys[1], keys[2])))
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{
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config_error("%s:%i: set::cloak-keys: All your 3 keys should be RANDOM, they should not be equal",
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ce->file->filename, ce->line_number);
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errors++;
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}
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*errs = errors;
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return errors ? -1 : 1;
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}
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int cloak_config_posttest(int *errs)
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{
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int errors = 0;
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if (nokeys)
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{
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config_error("set::cloak-keys missing!");
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errors++;
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}
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*errs = errors;
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return errors ? -1 : 1;
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}
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int cloak_config_run(ConfigFile *cf, ConfigEntry *ce, int type)
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{
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ConfigEntry *cep;
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char buf[4096];
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char result[128];
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if (type == CONFIG_SET)
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{
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/* set::cloak-method */
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if (!ce || !ce->name || strcmp(ce->name, "cloak-method"))
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return 0;
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if (!strcmp(ce->value, "ip"))
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CLOAK_IP_ONLY = 1;
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return 0;
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}
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if (type != CONFIG_CLOAKKEYS)
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return 0;
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/* config test should ensure this goes fine... */
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cep = ce->items;
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safe_strdup(cloak_key1, cep->name);
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cep = cep->next;
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safe_strdup(cloak_key2, cep->name);
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cep = cep->next;
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safe_strdup(cloak_key3, cep->name);
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/* Calculate checksum */
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ircsnprintf(buf, sizeof(buf), "%s:%s:%s", KEY1, KEY2, KEY3);
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ircsnprintf(cloak_checksum, sizeof(cloak_checksum), "SHA256:%s", sha256hash(result, buf, strlen(buf)));
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return 1;
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}
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char *hidehost(Client *client, char *host)
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{
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char *p;
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int host_type;
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if (CLOAK_IP_ONLY)
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host = GetIP(client);
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host_type = is_valid_ip(host);
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if (host_type == 4)
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return hidehost_ipv4(host);
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else if (host_type == 6)
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return hidehost_ipv6(host);
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else
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return hidehost_normalhost(host);
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}
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char *cloakcsum()
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{
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return cloak_checksum;
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}
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/** Downsamples a 256 bit result to 32 bits (SHA256 -> unsigned int) */
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static inline unsigned int downsample(char *i)
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{
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char r[4];
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r[0] = i[0] ^ i[1] ^ i[2] ^ i[3] ^ i[4] ^ i[5] ^ i[6] ^ i[7];
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r[1] = i[8] ^ i[9] ^ i[10] ^ i[11] ^ i[12] ^ i[13] ^ i[14] ^ i[15];
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r[2] = i[16] ^ i[17] ^ i[18] ^ i[19] ^ i[20] ^ i[21] ^ i[22] ^ i[23];
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r[3] = i[24] ^ i[25] ^ i[26] ^ i[27] ^ i[28] ^ i[29] ^ i[30] ^ i[31];
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return ( ((unsigned int)r[0] << 24) +
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((unsigned int)r[1] << 16) +
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((unsigned int)r[2] << 8) +
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(unsigned int)r[3]);
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}
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static char *hidehost_ipv4(char *host)
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{
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unsigned int a, b, c, d;
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static char buf[512], res[512], res2[512], result[128];
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unsigned long n;
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unsigned int alpha, beta, gamma;
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/*
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* Output: ALPHA.BETA.GAMMA.IP
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* ALPHA is unique for a.b.c.d
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* BETA is unique for a.b.c.*
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* GAMMA is unique for a.b.*
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* We cloak like this:
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* ALPHA = downsample(sha256(sha256("KEY2:A.B.C.D:KEY3")+"KEY1"));
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* BETA = downsample(sha256(sha256("KEY3:A.B.C:KEY1")+"KEY2"));
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* GAMMA = downsample(sha256(sha256("KEY1:A.B:KEY2")+"KEY3"));
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*/
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sscanf(host, "%u.%u.%u.%u", &a, &b, &c, &d);
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/* ALPHA... */
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ircsnprintf(buf, sizeof(buf), "%s:%s:%s", KEY2, host, KEY3);
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sha256hash_binary(res, buf, strlen(buf));
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strlcpy(res+SHA256_HASH_SIZE, KEY1, sizeof(res)-SHA256_HASH_SIZE); /* first bytes are filled, append our key.. */
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n = strlen(res+SHA256_HASH_SIZE) + SHA256_HASH_SIZE;
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sha256hash_binary(res2, res, n);
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alpha = downsample(res2);
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/* BETA... */
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ircsnprintf(buf, sizeof(buf), "%s:%d.%d.%d:%s", KEY3, a, b, c, KEY1);
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sha256hash_binary(res, buf, strlen(buf));
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strlcpy(res+SHA256_HASH_SIZE, KEY2, sizeof(res)-SHA256_HASH_SIZE); /* first bytes are filled, append our key.. */
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n = strlen(res+SHA256_HASH_SIZE) + SHA256_HASH_SIZE;
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sha256hash_binary(res2, res, n);
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beta = downsample(res2);
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/* GAMMA... */
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ircsnprintf(buf, sizeof(buf), "%s:%d.%d:%s", KEY1, a, b, KEY2);
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sha256hash_binary(res, buf, strlen(buf));
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strlcpy(res+SHA256_HASH_SIZE, KEY3, sizeof(res)-SHA256_HASH_SIZE); /* first bytes are filled, append our key.. */
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n = strlen(res+SHA256_HASH_SIZE) + SHA256_HASH_SIZE;
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sha256hash_binary(res2, res, n);
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gamma = downsample(res2);
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ircsnprintf(result, sizeof(result), "%X.%X.%X.IP", alpha, beta, gamma);
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return result;
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}
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static char *hidehost_ipv6(char *host)
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{
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unsigned int a, b, c, d, e, f, g, h;
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static char buf[512], res[512], res2[512], result[128];
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unsigned long n;
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unsigned int alpha, beta, gamma;
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/*
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* Output: ALPHA:BETA:GAMMA:IP
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* ALPHA is unique for a:b:c:d:e:f:g:h
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* BETA is unique for a:b:c:d:e:f:g
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* GAMMA is unique for a:b:c:d
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* We cloak like this:
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* ALPHA = downsample(sha256(sha256("KEY2:a:b:c:d:e:f:g:h:KEY3")+"KEY1"));
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* BETA = downsample(sha256(sha256("KEY3:a:b:c:d:e:f:g:KEY1")+"KEY2"));
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* GAMMA = downsample(sha256(sha256("KEY1:a:b:c:d:KEY2")+"KEY3"));
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*/
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sscanf(host, "%x:%x:%x:%x:%x:%x:%x:%x",
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&a, &b, &c, &d, &e, &f, &g, &h);
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/* ALPHA... */
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ircsnprintf(buf, sizeof(buf), "%s:%s:%s", KEY2, host, KEY3);
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sha256hash_binary(res, buf, strlen(buf));
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strlcpy(res+SHA256_HASH_SIZE, KEY1, sizeof(res)-SHA256_HASH_SIZE); /* first bytes are filled, append our key.. */
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n = strlen(res+SHA256_HASH_SIZE) + SHA256_HASH_SIZE;
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sha256hash_binary(res2, res, n);
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alpha = downsample(res2);
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/* BETA... */
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ircsnprintf(buf, sizeof(buf), "%s:%x:%x:%x:%x:%x:%x:%x:%s", KEY3, a, b, c, d, e, f, g, KEY1);
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sha256hash_binary(res, buf, strlen(buf));
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strlcpy(res+SHA256_HASH_SIZE, KEY2, sizeof(res)-SHA256_HASH_SIZE); /* first bytes are filled, append our key.. */
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n = strlen(res+SHA256_HASH_SIZE) + SHA256_HASH_SIZE;
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sha256hash_binary(res2, res, n);
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beta = downsample(res2);
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/* GAMMA... */
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ircsnprintf(buf, sizeof(buf), "%s:%x:%x:%x:%x:%s", KEY1, a, b, c, d, KEY2);
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sha256hash_binary(res, buf, strlen(buf));
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strlcpy(res+SHA256_HASH_SIZE, KEY3, sizeof(res)-SHA256_HASH_SIZE); /* first bytes are filled, append our key.. */
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n = strlen(res+SHA256_HASH_SIZE) + SHA256_HASH_SIZE;
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sha256hash_binary(res2, res, n);
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gamma = downsample(res2);
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ircsnprintf(result, sizeof(result), "%X:%X:%X:IP", alpha, beta, gamma);
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return result;
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}
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static char *hidehost_normalhost(char *host)
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{
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char *p;
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static char buf[512], res[512], res2[512], result[HOSTLEN+1];
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unsigned int alpha, n;
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ircsnprintf(buf, sizeof(buf), "%s:%s:%s", KEY1, host, KEY2);
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sha256hash_binary(res, buf, strlen(buf));
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strlcpy(res+SHA256_HASH_SIZE, KEY3, sizeof(res)-SHA256_HASH_SIZE); /* first bytes are filled, append our key.. */
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n = strlen(res+SHA256_HASH_SIZE) + SHA256_HASH_SIZE;
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sha256hash_binary(res2, res, n);
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alpha = downsample(res2);
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for (p = host; *p; p++)
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if (*p == '.')
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if (isalpha(*(p + 1)))
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break;
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if (*p)
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{
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unsigned int len;
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p++;
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ircsnprintf(result, sizeof(result), "%s-%X.", CLOAK_PREFIX, alpha);
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len = strlen(result) + strlen(p);
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if (len <= HOSTLEN)
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strlcat(result, p, sizeof(result));
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else
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strlcat(result, p + (len - HOSTLEN), sizeof(result));
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} else
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ircsnprintf(result, sizeof(result), "%s-%X", CLOAK_PREFIX, alpha);
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return result;
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}
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