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1 | /* | |
2 | * ircd-ratbox: A slightly useful ircd. | |
3 | * m_challenge.c: Allows an IRC Operator to securely authenticate. | |
4 | * | |
5 | * Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center | |
6 | * Copyright (C) 1996-2002 Hybrid Development Team | |
7 | * Copyright (C) 2002-2005 ircd-ratbox development team | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
22 | * USA | |
23 | * | |
24 | * $Id: m_challenge.c 3161 2007-01-25 07:23:01Z nenolod $ | |
25 | */ | |
26 | ||
27 | #include "stdinc.h" | |
28 | ||
29 | #ifdef HAVE_LIBCRYPTO | |
30 | #include <openssl/pem.h> | |
31 | #include <openssl/rand.h> | |
32 | #include <openssl/rsa.h> | |
33 | #include <openssl/md5.h> | |
34 | #include <openssl/bn.h> | |
35 | #include <openssl/evp.h> | |
36 | #include <openssl/err.h> | |
37 | #endif | |
38 | ||
39 | #include "client.h" | |
40 | #include "ircd.h" | |
41 | #include "modules.h" | |
42 | #include "numeric.h" | |
43 | #include "send.h" | |
44 | #include "s_conf.h" | |
45 | #include "msg.h" | |
46 | #include "parse.h" | |
47 | #include "match.h" | |
48 | #include "logger.h" | |
49 | #include "s_user.h" | |
50 | #include "cache.h" | |
51 | #include "s_newconf.h" | |
52 | ||
53 | #define CHALLENGE_WIDTH BUFSIZE - (NICKLEN + HOSTLEN + 12) | |
54 | #define CHALLENGE_EXPIRES 180 /* 180 seconds should be more than long enough */ | |
55 | #define CHALLENGE_SECRET_LENGTH 128 /* how long our challenge secret should be */ | |
56 | ||
57 | #ifndef HAVE_LIBCRYPTO | |
58 | /* Maybe this should be an error or something?-davidt */ | |
59 | /* now it is -larne */ | |
60 | static int challenge_load(void) | |
61 | { | |
62 | #ifndef STATIC_MODULES | |
63 | sendto_realops_snomask(SNO_GENERAL, L_ALL, | |
64 | "Challenge module not loaded because OpenSSL is not available."); | |
65 | ilog(L_MAIN, "Challenge module not loaded because OpenSSL is not available."); | |
66 | return -1; | |
67 | #else | |
68 | return 0; | |
69 | #endif | |
70 | } | |
71 | ||
72 | DECLARE_MODULE_AV1(challenge, challenge_load, NULL, NULL, NULL, NULL, "$Revision: 3161 $"); | |
73 | #else | |
74 | ||
75 | static int m_challenge(struct Client *, struct Client *, int, const char **); | |
76 | ||
77 | /* We have openssl support, so include /CHALLENGE */ | |
78 | struct Message challenge_msgtab = { | |
79 | "CHALLENGE", 0, 0, 0, MFLG_SLOW, | |
80 | {mg_unreg, {m_challenge, 2}, mg_ignore, mg_ignore, mg_ignore, {m_challenge, 2}} | |
81 | }; | |
82 | ||
83 | mapi_clist_av1 challenge_clist[] = { &challenge_msgtab, NULL }; | |
84 | DECLARE_MODULE_AV1(challenge, NULL, NULL, challenge_clist, NULL, NULL, "$Revision: 3161 $"); | |
85 | ||
86 | static int generate_challenge(char **r_challenge, char **r_response, RSA * key); | |
87 | ||
88 | static void | |
89 | cleanup_challenge(struct Client *target_p) | |
90 | { | |
91 | if(target_p->localClient == NULL) | |
92 | return; | |
93 | ||
94 | rb_free(target_p->localClient->challenge); | |
95 | rb_free(target_p->localClient->opername); | |
96 | target_p->localClient->challenge = NULL; | |
97 | target_p->localClient->opername = NULL; | |
98 | target_p->localClient->chal_time = 0; | |
99 | } | |
100 | ||
101 | /* | |
102 | * m_challenge - generate RSA challenge for wouldbe oper | |
103 | * parv[0] = sender prefix | |
104 | * parv[1] = operator to challenge for, or +response | |
105 | * | |
106 | */ | |
107 | static int | |
108 | m_challenge(struct Client *client_p, struct Client *source_p, int parc, const char *parv[]) | |
109 | { | |
110 | struct oper_conf *oper_p; | |
111 | char *challenge = NULL; /* to placate gcc */ | |
112 | char chal_line[CHALLENGE_WIDTH]; | |
113 | unsigned char *b_response; | |
114 | size_t cnt; | |
115 | int len = 0; | |
116 | ||
117 | /* if theyre an oper, reprint oper motd and ignore */ | |
118 | if(IsOper(source_p)) | |
119 | { | |
120 | sendto_one(source_p, form_str(RPL_YOUREOPER), me.name, source_p->name); | |
121 | send_oper_motd(source_p); | |
122 | return 0; | |
123 | } | |
124 | ||
125 | if(*parv[1] == '+') | |
126 | { | |
127 | /* Ignore it if we aren't expecting this... -A1kmm */ | |
128 | if(!source_p->localClient->challenge) | |
129 | return 0; | |
130 | ||
131 | if((rb_current_time() - source_p->localClient->chal_time) > CHALLENGE_EXPIRES) | |
132 | { | |
133 | sendto_one(source_p, form_str(ERR_PASSWDMISMATCH), me.name, source_p->name); | |
134 | ilog(L_FOPER, "EXPIRED CHALLENGE (%s) by (%s!%s@%s) (%s)", | |
135 | source_p->localClient->opername, source_p->name, | |
136 | source_p->username, source_p->host, source_p->sockhost); | |
137 | ||
138 | if(ConfigFileEntry.failed_oper_notice) | |
139 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
140 | "Expired CHALLENGE attempt by %s (%s@%s)", | |
141 | source_p->name, source_p->username, | |
142 | source_p->host); | |
143 | cleanup_challenge(source_p); | |
144 | return 0; | |
145 | } | |
146 | ||
147 | b_response = rb_base64_decode((const unsigned char *)++parv[1], strlen(parv[1]), &len); | |
148 | ||
149 | if(len != SHA_DIGEST_LENGTH || | |
150 | memcmp(source_p->localClient->challenge, b_response, SHA_DIGEST_LENGTH)) | |
151 | { | |
152 | sendto_one(source_p, form_str(ERR_PASSWDMISMATCH), me.name, source_p->name); | |
153 | ilog(L_FOPER, "FAILED CHALLENGE (%s) by (%s!%s@%s) (%s)", | |
154 | source_p->localClient->opername, source_p->name, | |
155 | source_p->username, source_p->host, source_p->sockhost); | |
156 | ||
157 | if(ConfigFileEntry.failed_oper_notice) | |
158 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
159 | "Failed CHALLENGE attempt by %s (%s@%s)", | |
160 | source_p->name, source_p->username, | |
161 | source_p->host); | |
162 | ||
163 | rb_free(b_response); | |
164 | cleanup_challenge(source_p); | |
165 | return 0; | |
166 | } | |
167 | ||
168 | rb_free(b_response); | |
169 | ||
170 | oper_p = find_oper_conf(source_p->username, source_p->orighost, | |
171 | source_p->sockhost, | |
172 | source_p->localClient->opername); | |
173 | ||
174 | if(oper_p == NULL) | |
175 | { | |
176 | sendto_one(source_p, form_str(ERR_NOOPERHOST), | |
177 | me.name, source_p->name); | |
178 | ilog(L_FOPER, "FAILED OPER (%s) by (%s!%s@%s) (%s)", | |
179 | source_p->localClient->opername, source_p->name, | |
180 | source_p->username, source_p->host, | |
181 | source_p->sockhost); | |
182 | ||
183 | if(ConfigFileEntry.failed_oper_notice) | |
184 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
185 | "Failed CHALLENGE attempt - host mismatch by %s (%s@%s)", | |
186 | source_p->name, source_p->username, | |
187 | source_p->host); | |
188 | return 0; | |
189 | } | |
190 | ||
191 | cleanup_challenge(source_p); | |
192 | ||
193 | oper_up(source_p, oper_p); | |
194 | ||
195 | ilog(L_OPERED, "OPER %s by %s!%s@%s (%s)", | |
196 | source_p->localClient->opername, source_p->name, | |
197 | source_p->username, source_p->host, source_p->sockhost); | |
198 | return 0; | |
199 | } | |
200 | ||
201 | cleanup_challenge(source_p); | |
202 | ||
203 | oper_p = find_oper_conf(source_p->username, source_p->orighost, | |
204 | source_p->sockhost, parv[1]); | |
205 | ||
206 | if(oper_p == NULL) | |
207 | { | |
208 | sendto_one(source_p, form_str(ERR_NOOPERHOST), me.name, source_p->name); | |
209 | ilog(L_FOPER, "FAILED OPER (%s) by (%s!%s@%s) (%s)", | |
210 | parv[1], source_p->name, | |
211 | source_p->username, source_p->host, source_p->sockhost); | |
212 | ||
213 | if(ConfigFileEntry.failed_oper_notice) | |
214 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
215 | "Failed CHALLENGE attempt - host mismatch by %s (%s@%s)", | |
216 | source_p->name, source_p->username, source_p->host); | |
217 | return 0; | |
218 | } | |
219 | ||
220 | if(!oper_p->rsa_pubkey) | |
221 | { | |
222 | sendto_one_notice(source_p, ":I'm sorry, PK authentication is not enabled for your oper{} block."); | |
223 | return 0; | |
224 | } | |
225 | ||
226 | if(IsOperConfNeedSSL(oper_p) && !IsSSLClient(source_p)) | |
227 | { | |
228 | sendto_one(source_p, form_str(ERR_NOOPERHOST), me.name, source_p->name); | |
229 | ilog(L_FOPER, "FAILED CHALLENGE (%s) by (%s!%s@%s) (%s) -- requires SSL/TLS", | |
230 | parv[1], source_p->name, source_p->username, source_p->host, | |
231 | source_p->sockhost); | |
232 | ||
233 | if(ConfigFileEntry.failed_oper_notice) | |
234 | { | |
235 | sendto_realops_snomask(SNO_GENERAL, L_ALL, | |
236 | "Failed CHALLENGE attempt - missing SSL/TLS by %s (%s@%s)", | |
237 | source_p->name, source_p->username, source_p->host); | |
238 | } | |
239 | return 0; | |
240 | } | |
241 | ||
242 | if(!generate_challenge(&challenge, &(source_p->localClient->challenge), oper_p->rsa_pubkey)) | |
243 | { | |
244 | char *chal = challenge; | |
245 | source_p->localClient->chal_time = rb_current_time(); | |
246 | for(;;) | |
247 | { | |
248 | cnt = rb_strlcpy(chal_line, chal, CHALLENGE_WIDTH); | |
249 | sendto_one(source_p, form_str(RPL_RSACHALLENGE2), me.name, source_p->name, chal_line); | |
250 | if(cnt > CHALLENGE_WIDTH) | |
251 | chal += CHALLENGE_WIDTH - 1; | |
252 | else | |
253 | break; | |
254 | ||
255 | } | |
256 | sendto_one(source_p, form_str(RPL_ENDOFRSACHALLENGE2), | |
257 | me.name, source_p->name); | |
258 | rb_free(challenge); | |
259 | source_p->localClient->opername = rb_strdup(oper_p->name); | |
260 | } | |
261 | else | |
262 | sendto_one_notice(source_p, ":Failed to generate challenge."); | |
263 | ||
264 | return 0; | |
265 | } | |
266 | ||
267 | static int | |
268 | generate_challenge(char **r_challenge, char **r_response, RSA * rsa) | |
269 | { | |
270 | SHA_CTX ctx; | |
271 | unsigned char secret[CHALLENGE_SECRET_LENGTH], *tmp; | |
272 | unsigned long length; | |
273 | unsigned long e = 0; | |
274 | unsigned long cnt = 0; | |
275 | int ret; | |
276 | ||
277 | if(!rsa) | |
278 | return -1; | |
279 | if(rb_get_random(secret, CHALLENGE_SECRET_LENGTH)) | |
280 | { | |
281 | SHA1_Init(&ctx); | |
282 | SHA1_Update(&ctx, (uint8_t *)secret, CHALLENGE_SECRET_LENGTH); | |
283 | *r_response = malloc(SHA_DIGEST_LENGTH); | |
284 | SHA1_Final((uint8_t *)*r_response, &ctx); | |
285 | ||
286 | length = RSA_size(rsa); | |
287 | tmp = rb_malloc(length); | |
288 | ret = RSA_public_encrypt(CHALLENGE_SECRET_LENGTH, secret, tmp, rsa, RSA_PKCS1_OAEP_PADDING); | |
289 | ||
290 | if(ret >= 0) | |
291 | { | |
292 | *r_challenge = (char *)rb_base64_encode(tmp, ret); | |
293 | rb_free(tmp); | |
294 | return 0; | |
295 | } | |
296 | ||
297 | rb_free(tmp); | |
298 | rb_free(*r_response); | |
299 | *r_response = NULL; | |
300 | } | |
301 | ||
302 | ERR_load_crypto_strings(); | |
303 | while ((cnt < 100) && (e = ERR_get_error())) | |
304 | { | |
305 | ilog(L_MAIN, "SSL error: %s", ERR_error_string(e, 0)); | |
306 | cnt++; | |
307 | } | |
308 | ||
309 | return (-1); | |
310 | } | |
311 | ||
312 | #endif /* HAVE_LIBCRYPTO */ |