/* * 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 # include # include # include # include #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_NETWIDE, "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); #if (OPENSSL_VERSION_NUMBER >= 0x30000000L) static bool generate_challenge(char **r_challenge, unsigned char **r_response, EVP_PKEY *key); #else static bool generate_challenge(char **r_challenge, unsigned char **r_response, RSA *key); #endif static void cleanup_challenge(struct Client *target_p) { if(target_p->localClient == NULL) return; rb_free(target_p->localClient->challenge); rb_free(target_p->user->opername); target_p->localClient->challenge = NULL; target_p->user->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 (ConfigFileEntry.oper_secure_only && !IsSecureClient(source_p)) { sendto_one_notice(source_p, ":You must be using a secure connection to /CHALLENGE on this server"); if (ConfigFileEntry.failed_oper_notice) { sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, "Failed CHALLENGE attempt - missing secure connection by %s (%s@%s)", source_p->name, source_p->username, source_p->host); } return; } /* 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->user->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->user->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->user->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->user->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); cleanup_challenge(source_p); return; } cleanup_challenge(source_p); oper_up(source_p, oper_p); ilog(L_OPERED, "OPER %s by %s!%s@%s (%s)", source_p->user->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) && !IsSecureClient(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_NETWIDE, "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 || rb_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_NETWIDE, "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->user->opername = rb_strdup(oper_p->name); } else sendto_one_notice(source_p, ":Failed to generate challenge."); } static bool #if (OPENSSL_VERSION_NUMBER >= 0x30000000L) generate_challenge(char **r_challenge, unsigned char **r_response, EVP_PKEY *key) #else generate_challenge(char **r_challenge, unsigned char **r_response, RSA *key) #endif { unsigned char secret[CHALLENGE_SECRET_LENGTH]; unsigned char *tmp = NULL; unsigned long e = 0; unsigned long cnt = 0; bool retval = false; size_t length; EVP_MD_CTX *mctx = NULL; #if (OPENSSL_VERSION_NUMBER >= 0x30000000L) EVP_PKEY_CTX *pctx = NULL; #endif if(!rb_get_random(secret, sizeof secret)) return false; if((*r_response = rb_malloc(SHA_DIGEST_LENGTH)) == NULL) return false; if((mctx = EVP_MD_CTX_new()) == NULL) goto fail; if(EVP_DigestInit(mctx, EVP_sha1()) < 1) goto fail; if(EVP_DigestUpdate(mctx, secret, sizeof secret) < 1) goto fail; if(EVP_DigestFinal(mctx, *r_response, NULL) < 1) goto fail; #if (OPENSSL_VERSION_NUMBER >= 0x30000000L) if((length = (size_t) EVP_PKEY_get_size(key)) < 1) goto fail; if((tmp = rb_malloc(length)) == NULL) goto fail; if((pctx = EVP_PKEY_CTX_new(key, NULL)) == NULL) goto fail; if(EVP_PKEY_encrypt_init(pctx) < 1) goto fail; if(EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_OAEP_PADDING) < 1) goto fail; if(EVP_PKEY_encrypt(pctx, tmp, &length, secret, sizeof secret) < 1) goto fail; #else if((length = (size_t) RSA_size(key)) < 1) goto fail; if((tmp = rb_malloc(length)) == NULL) goto fail; if(RSA_public_encrypt(sizeof secret, secret, tmp, key, RSA_PKCS1_OAEP_PADDING) < 1) goto fail; #endif if((*r_challenge = (char *) rb_base64_encode(tmp, (int) length)) == NULL) goto fail; retval = true; goto done; fail: while ((cnt < 100) && (e = ERR_get_error())) { ilog(L_MAIN, "OpenSSL Error (CHALLENGE): %s", ERR_error_string(e, 0)); cnt++; } rb_free(*r_response); *r_response = NULL; done: EVP_MD_CTX_free(mctx); #if (OPENSSL_VERSION_NUMBER >= 0x30000000L) EVP_PKEY_CTX_free(pctx); #endif rb_free(tmp); return retval; } #endif /* HAVE_LIBCRYPTO */