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construct/modules/m_challenge.c
Elizabeth Myers 3c7d6fcce7 Message handlers should return void.
Also fix up some return values and stuff to use bool (or void if
nothing). I just did it whilst I was here.

According to jilles, the return value used to signify whether or not the
client had exited. This was error-prone and was fixed a long, long time
ago, but the return value was left int for historical reasons.

Since the return type is not used (and has no clear use case anyway),
it's safe to just get rid of it.
2016-03-09 01:37:03 -06:00

328 lines
9.7 KiB
C

/*
* ircd-ratbox: A slightly useful ircd.
* m_challenge.c: Allows an IRC Operator to securely authenticate.
*
* Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
* Copyright (C) 1996-2002 Hybrid Development Team
* Copyright (C) 2002-2005 ircd-ratbox development team
*
* 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
*/
#include "stdinc.h"
#ifdef HAVE_LIBCRYPTO
#include <openssl/pem.h>
#include <openssl/rand.h>
#include <openssl/rsa.h>
#include <openssl/md5.h>
#include <openssl/bn.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#endif
#include "client.h"
#include "ircd.h"
#include "modules.h"
#include "numeric.h"
#include "send.h"
#include "s_conf.h"
#include "msg.h"
#include "parse.h"
#include "match.h"
#include "logger.h"
#include "s_user.h"
#include "cache.h"
#include "s_newconf.h"
#define CHALLENGE_WIDTH BUFSIZE - (NICKLEN + HOSTLEN + 12)
#define CHALLENGE_EXPIRES 180 /* 180 seconds should be more than long enough */
#define CHALLENGE_SECRET_LENGTH 128 /* how long our challenge secret should be */
#ifndef HAVE_LIBCRYPTO
static const char challenge_desc[] = "Does nothing as OpenSSL was not enabled.";
/* Maybe this should be an error or something?-davidt */
/* now it is -larne */
static int challenge_load(void)
{
sendto_realops_snomask(SNO_GENERAL, L_ALL,
"Challenge module not loaded because OpenSSL is not available.");
ilog(L_MAIN, "Challenge module not loaded because OpenSSL is not available.");
return -1;
}
DECLARE_MODULE_AV2(challenge, challenge_load, NULL, NULL, NULL, NULL, NULL, NULL, challenge_desc);
#else
static const char challenge_desc[] =
"Provides the challenge-response facility used for becoming an IRC operator";
static void m_challenge(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
/* We have openssl support, so include /CHALLENGE */
struct Message challenge_msgtab = {
"CHALLENGE", 0, 0, 0, 0,
{mg_unreg, {m_challenge, 2}, mg_ignore, mg_ignore, mg_ignore, {m_challenge, 2}}
};
mapi_clist_av1 challenge_clist[] = { &challenge_msgtab, NULL };
DECLARE_MODULE_AV2(challenge, NULL, NULL, challenge_clist, NULL, NULL, NULL, NULL, challenge_desc);
static bool generate_challenge(char **r_challenge, char **r_response, RSA * key);
static void
cleanup_challenge(struct Client *target_p)
{
if(target_p->localClient == NULL)
return;
rb_free(target_p->localClient->challenge);
rb_free(target_p->localClient->opername);
target_p->localClient->challenge = NULL;
target_p->localClient->opername = NULL;
target_p->localClient->chal_time = 0;
}
/*
* m_challenge - generate RSA challenge for wouldbe oper
* parv[1] = operator to challenge for, or +response
*/
static void
m_challenge(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p, int parc, const char *parv[])
{
struct oper_conf *oper_p;
char *challenge = NULL; /* to placate gcc */
char chal_line[CHALLENGE_WIDTH];
unsigned char *b_response;
size_t cnt;
int len = 0;
/* if theyre an oper, reprint oper motd and ignore */
if(IsOper(source_p))
{
sendto_one(source_p, form_str(RPL_YOUREOPER), me.name, source_p->name);
send_oper_motd(source_p);
return;
}
if(*parv[1] == '+')
{
/* Ignore it if we aren't expecting this... -A1kmm */
if(!source_p->localClient->challenge)
return;
if((rb_current_time() - source_p->localClient->chal_time) > CHALLENGE_EXPIRES)
{
sendto_one(source_p, form_str(ERR_PASSWDMISMATCH), me.name, source_p->name);
ilog(L_FOPER, "EXPIRED CHALLENGE (%s) by (%s!%s@%s) (%s)",
source_p->localClient->opername, source_p->name,
source_p->username, source_p->host, source_p->sockhost);
if(ConfigFileEntry.failed_oper_notice)
sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
"Expired CHALLENGE attempt by %s (%s@%s)",
source_p->name, source_p->username,
source_p->host);
cleanup_challenge(source_p);
return;
}
parv[1]++;
b_response = rb_base64_decode((const unsigned char *)parv[1], strlen(parv[1]), &len);
if(len != SHA_DIGEST_LENGTH ||
memcmp(source_p->localClient->challenge, b_response, SHA_DIGEST_LENGTH))
{
sendto_one(source_p, form_str(ERR_PASSWDMISMATCH), me.name, source_p->name);
ilog(L_FOPER, "FAILED CHALLENGE (%s) by (%s!%s@%s) (%s)",
source_p->localClient->opername, source_p->name,
source_p->username, source_p->host, source_p->sockhost);
if(ConfigFileEntry.failed_oper_notice)
sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
"Failed CHALLENGE attempt by %s (%s@%s)",
source_p->name, source_p->username,
source_p->host);
rb_free(b_response);
cleanup_challenge(source_p);
return;
}
rb_free(b_response);
oper_p = find_oper_conf(source_p->username, source_p->orighost,
source_p->sockhost,
source_p->localClient->opername);
if(oper_p == NULL)
{
sendto_one_numeric(source_p, ERR_NOOPERHOST, form_str(ERR_NOOPERHOST));
ilog(L_FOPER, "FAILED OPER (%s) by (%s!%s@%s) (%s)",
source_p->localClient->opername, source_p->name,
source_p->username, source_p->host,
source_p->sockhost);
if(ConfigFileEntry.failed_oper_notice)
sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
"Failed CHALLENGE attempt - host mismatch by %s (%s@%s)",
source_p->name, source_p->username,
source_p->host);
return;
}
cleanup_challenge(source_p);
oper_up(source_p, oper_p);
ilog(L_OPERED, "OPER %s by %s!%s@%s (%s)",
source_p->localClient->opername, source_p->name,
source_p->username, source_p->host, source_p->sockhost);
return;
}
cleanup_challenge(source_p);
oper_p = find_oper_conf(source_p->username, source_p->orighost,
source_p->sockhost, parv[1]);
if(oper_p == NULL)
{
sendto_one_numeric(source_p, ERR_NOOPERHOST, form_str(ERR_NOOPERHOST));
ilog(L_FOPER, "FAILED OPER (%s) by (%s!%s@%s) (%s)",
parv[1], source_p->name,
source_p->username, source_p->host, source_p->sockhost);
if(ConfigFileEntry.failed_oper_notice)
sendto_realops_snomask(SNO_GENERAL, L_NETWIDE,
"Failed CHALLENGE attempt - host mismatch by %s (%s@%s)",
source_p->name, source_p->username, source_p->host);
return;
}
if(!oper_p->rsa_pubkey)
{
sendto_one_notice(source_p, ":I'm sorry, PK authentication is not enabled for your oper{} block.");
return;
}
if(IsOperConfNeedSSL(oper_p) && !IsSSLClient(source_p))
{
sendto_one_numeric(source_p, ERR_NOOPERHOST, form_str(ERR_NOOPERHOST));
ilog(L_FOPER, "FAILED CHALLENGE (%s) by (%s!%s@%s) (%s) -- requires SSL/TLS",
parv[1], source_p->name, source_p->username, source_p->host,
source_p->sockhost);
if(ConfigFileEntry.failed_oper_notice)
{
sendto_realops_snomask(SNO_GENERAL, L_ALL,
"Failed CHALLENGE attempt - missing SSL/TLS by %s (%s@%s)",
source_p->name, source_p->username, source_p->host);
}
return;
}
if (oper_p->certfp != NULL)
{
if (source_p->certfp == NULL || strcasecmp(source_p->certfp, oper_p->certfp))
{
sendto_one_numeric(source_p, ERR_NOOPERHOST, form_str(ERR_NOOPERHOST));
ilog(L_FOPER, "FAILED OPER (%s) by (%s!%s@%s) (%s) -- client certificate fingerprint mismatch",
parv[1], source_p->name,
source_p->username, source_p->host, source_p->sockhost);
if(ConfigFileEntry.failed_oper_notice)
{
sendto_realops_snomask(SNO_GENERAL, L_ALL,
"Failed OPER attempt - client certificate fingerprint mismatch by %s (%s@%s)",
source_p->name, source_p->username, source_p->host);
}
return;
}
}
if(generate_challenge(&challenge, &(source_p->localClient->challenge), oper_p->rsa_pubkey))
{
char *chal = challenge;
source_p->localClient->chal_time = rb_current_time();
for(;;)
{
cnt = rb_strlcpy(chal_line, chal, CHALLENGE_WIDTH);
sendto_one(source_p, form_str(RPL_RSACHALLENGE2), me.name, source_p->name, chal_line);
if(cnt > CHALLENGE_WIDTH)
chal += CHALLENGE_WIDTH - 1;
else
break;
}
sendto_one(source_p, form_str(RPL_ENDOFRSACHALLENGE2),
me.name, source_p->name);
rb_free(challenge);
source_p->localClient->opername = rb_strdup(oper_p->name);
}
else
sendto_one_notice(source_p, ":Failed to generate challenge.");
}
static bool
generate_challenge(char **r_challenge, char **r_response, RSA * rsa)
{
SHA_CTX ctx;
unsigned char secret[CHALLENGE_SECRET_LENGTH], *tmp;
unsigned long length;
unsigned long e = 0;
unsigned long cnt = 0;
int ret;
if(!rsa)
return false;
if(rb_get_random(secret, CHALLENGE_SECRET_LENGTH))
{
SHA1_Init(&ctx);
SHA1_Update(&ctx, (uint8_t *)secret, CHALLENGE_SECRET_LENGTH);
*r_response = malloc(SHA_DIGEST_LENGTH);
SHA1_Final((uint8_t *)*r_response, &ctx);
length = RSA_size(rsa);
tmp = rb_malloc(length);
ret = RSA_public_encrypt(CHALLENGE_SECRET_LENGTH, secret, tmp, rsa, RSA_PKCS1_OAEP_PADDING);
if(ret >= 0)
{
*r_challenge = (char *)rb_base64_encode(tmp, ret);
rb_free(tmp);
return true;
}
rb_free(tmp);
rb_free(*r_response);
*r_response = NULL;
}
ERR_load_crypto_strings();
while ((cnt < 100) && (e = ERR_get_error()))
{
ilog(L_MAIN, "SSL error: %s", ERR_error_string(e, 0));
cnt++;
}
return false;
}
#endif /* HAVE_LIBCRYPTO */