]>
Commit | Line | Data |
---|---|---|
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 | ||
25 | #include "stdinc.h" | |
26 | ||
27 | #ifdef HAVE_LIBCRYPTO | |
28 | #include <openssl/pem.h> | |
29 | #include <openssl/rand.h> | |
30 | #include <openssl/rsa.h> | |
31 | #include <openssl/md5.h> | |
32 | #include <openssl/bn.h> | |
33 | #include <openssl/evp.h> | |
34 | #include <openssl/err.h> | |
35 | #endif | |
36 | ||
37 | #include "client.h" | |
38 | #include "ircd.h" | |
39 | #include "modules.h" | |
40 | #include "numeric.h" | |
41 | #include "send.h" | |
42 | #include "s_conf.h" | |
43 | #include "msg.h" | |
44 | #include "parse.h" | |
45 | #include "match.h" | |
46 | #include "logger.h" | |
47 | #include "s_user.h" | |
48 | #include "cache.h" | |
49 | #include "s_newconf.h" | |
50 | ||
51 | #define CHALLENGE_WIDTH BUFSIZE - (NICKLEN + HOSTLEN + 12) | |
52 | #define CHALLENGE_EXPIRES 180 /* 180 seconds should be more than long enough */ | |
53 | #define CHALLENGE_SECRET_LENGTH 128 /* how long our challenge secret should be */ | |
54 | ||
55 | #ifndef HAVE_LIBCRYPTO | |
56 | ||
57 | static const char challenge_desc[] = "Does nothing as OpenSSL was not enabled."; | |
58 | ||
59 | /* Maybe this should be an error or something?-davidt */ | |
60 | /* now it is -larne */ | |
61 | static int challenge_load(void) | |
62 | { | |
63 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
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 | } | |
68 | ||
69 | DECLARE_MODULE_AV2(challenge, challenge_load, NULL, NULL, NULL, NULL, NULL, NULL, challenge_desc); | |
70 | #else | |
71 | ||
72 | static const char challenge_desc[] = | |
73 | "Provides the challenge-response facility used for becoming an IRC operator"; | |
74 | ||
75 | static void m_challenge(struct MsgBuf *, 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, 0, | |
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 | ||
85 | DECLARE_MODULE_AV2(challenge, NULL, NULL, challenge_clist, NULL, NULL, NULL, NULL, challenge_desc); | |
86 | ||
87 | static bool generate_challenge(char **r_challenge, char **r_response, RSA * key); | |
88 | ||
89 | static void | |
90 | cleanup_challenge(struct Client *target_p) | |
91 | { | |
92 | if(target_p->localClient == NULL) | |
93 | return; | |
94 | ||
95 | rb_free(target_p->localClient->challenge); | |
96 | rb_free(target_p->user->opername); | |
97 | target_p->localClient->challenge = NULL; | |
98 | target_p->user->opername = NULL; | |
99 | target_p->localClient->chal_time = 0; | |
100 | } | |
101 | ||
102 | /* | |
103 | * m_challenge - generate RSA challenge for wouldbe oper | |
104 | * parv[1] = operator to challenge for, or +response | |
105 | */ | |
106 | static void | |
107 | m_challenge(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p, int parc, const char *parv[]) | |
108 | { | |
109 | struct oper_conf *oper_p; | |
110 | char *challenge = NULL; /* to placate gcc */ | |
111 | char chal_line[CHALLENGE_WIDTH]; | |
112 | unsigned char *b_response; | |
113 | size_t cnt; | |
114 | int len = 0; | |
115 | ||
116 | if (ConfigFileEntry.oper_secure_only && !IsSecureClient(source_p)) | |
117 | { | |
118 | sendto_one_notice(source_p, ":You must be using a secure connection to /CHALLENGE on this server"); | |
119 | if (ConfigFileEntry.failed_oper_notice) | |
120 | { | |
121 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
122 | "Failed CHALLENGE attempt - missing secure connection by %s (%s@%s)", | |
123 | source_p->name, source_p->username, source_p->host); | |
124 | } | |
125 | return; | |
126 | } | |
127 | ||
128 | /* if theyre an oper, reprint oper motd and ignore */ | |
129 | if(IsOper(source_p)) | |
130 | { | |
131 | sendto_one(source_p, form_str(RPL_YOUREOPER), me.name, source_p->name); | |
132 | send_oper_motd(source_p); | |
133 | return; | |
134 | } | |
135 | ||
136 | if(*parv[1] == '+') | |
137 | { | |
138 | /* Ignore it if we aren't expecting this... -A1kmm */ | |
139 | if(!source_p->localClient->challenge) | |
140 | return; | |
141 | ||
142 | if((rb_current_time() - source_p->localClient->chal_time) > CHALLENGE_EXPIRES) | |
143 | { | |
144 | sendto_one(source_p, form_str(ERR_PASSWDMISMATCH), me.name, source_p->name); | |
145 | ilog(L_FOPER, "EXPIRED CHALLENGE (%s) by (%s!%s@%s) (%s)", | |
146 | source_p->user->opername, source_p->name, | |
147 | source_p->username, source_p->host, source_p->sockhost); | |
148 | ||
149 | if(ConfigFileEntry.failed_oper_notice) | |
150 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
151 | "Expired CHALLENGE attempt by %s (%s@%s)", | |
152 | source_p->name, source_p->username, | |
153 | source_p->host); | |
154 | cleanup_challenge(source_p); | |
155 | return; | |
156 | } | |
157 | ||
158 | parv[1]++; | |
159 | b_response = rb_base64_decode((const unsigned char *)parv[1], strlen(parv[1]), &len); | |
160 | ||
161 | if(len != SHA_DIGEST_LENGTH || | |
162 | memcmp(source_p->localClient->challenge, b_response, SHA_DIGEST_LENGTH)) | |
163 | { | |
164 | sendto_one(source_p, form_str(ERR_PASSWDMISMATCH), me.name, source_p->name); | |
165 | ilog(L_FOPER, "FAILED CHALLENGE (%s) by (%s!%s@%s) (%s)", | |
166 | source_p->user->opername, source_p->name, | |
167 | source_p->username, source_p->host, source_p->sockhost); | |
168 | ||
169 | if(ConfigFileEntry.failed_oper_notice) | |
170 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
171 | "Failed CHALLENGE attempt by %s (%s@%s)", | |
172 | source_p->name, source_p->username, | |
173 | source_p->host); | |
174 | ||
175 | rb_free(b_response); | |
176 | cleanup_challenge(source_p); | |
177 | return; | |
178 | } | |
179 | ||
180 | rb_free(b_response); | |
181 | ||
182 | oper_p = find_oper_conf(source_p->username, source_p->orighost, | |
183 | source_p->sockhost, | |
184 | source_p->user->opername); | |
185 | ||
186 | if(oper_p == NULL) | |
187 | { | |
188 | sendto_one_numeric(source_p, ERR_NOOPERHOST, form_str(ERR_NOOPERHOST)); | |
189 | ilog(L_FOPER, "FAILED OPER (%s) by (%s!%s@%s) (%s)", | |
190 | source_p->user->opername, source_p->name, | |
191 | source_p->username, source_p->host, | |
192 | source_p->sockhost); | |
193 | ||
194 | if(ConfigFileEntry.failed_oper_notice) | |
195 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
196 | "Failed CHALLENGE attempt - host mismatch by %s (%s@%s)", | |
197 | source_p->name, source_p->username, | |
198 | source_p->host); | |
199 | cleanup_challenge(source_p); | |
200 | return; | |
201 | } | |
202 | ||
203 | cleanup_challenge(source_p); | |
204 | ||
205 | oper_up(source_p, oper_p); | |
206 | ||
207 | ilog(L_OPERED, "OPER %s by %s!%s@%s (%s)", | |
208 | source_p->user->opername, source_p->name, | |
209 | source_p->username, source_p->host, source_p->sockhost); | |
210 | return; | |
211 | } | |
212 | ||
213 | cleanup_challenge(source_p); | |
214 | ||
215 | oper_p = find_oper_conf(source_p->username, source_p->orighost, | |
216 | source_p->sockhost, parv[1]); | |
217 | ||
218 | if(oper_p == NULL) | |
219 | { | |
220 | sendto_one_numeric(source_p, ERR_NOOPERHOST, form_str(ERR_NOOPERHOST)); | |
221 | ilog(L_FOPER, "FAILED OPER (%s) by (%s!%s@%s) (%s)", | |
222 | parv[1], source_p->name, | |
223 | source_p->username, source_p->host, source_p->sockhost); | |
224 | ||
225 | if(ConfigFileEntry.failed_oper_notice) | |
226 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
227 | "Failed CHALLENGE attempt - host mismatch by %s (%s@%s)", | |
228 | source_p->name, source_p->username, source_p->host); | |
229 | return; | |
230 | } | |
231 | ||
232 | if(!oper_p->rsa_pubkey) | |
233 | { | |
234 | sendto_one_notice(source_p, ":I'm sorry, PK authentication is not enabled for your oper{} block."); | |
235 | return; | |
236 | } | |
237 | ||
238 | if(IsOperConfNeedSSL(oper_p) && !IsSecureClient(source_p)) | |
239 | { | |
240 | sendto_one_numeric(source_p, ERR_NOOPERHOST, form_str(ERR_NOOPERHOST)); | |
241 | ilog(L_FOPER, "FAILED CHALLENGE (%s) by (%s!%s@%s) (%s) -- requires SSL/TLS", | |
242 | parv[1], source_p->name, source_p->username, source_p->host, | |
243 | source_p->sockhost); | |
244 | ||
245 | if(ConfigFileEntry.failed_oper_notice) | |
246 | { | |
247 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
248 | "Failed CHALLENGE attempt - missing SSL/TLS by %s (%s@%s)", | |
249 | source_p->name, source_p->username, source_p->host); | |
250 | } | |
251 | return; | |
252 | } | |
253 | ||
254 | if (oper_p->certfp != NULL) | |
255 | { | |
256 | if (source_p->certfp == NULL || rb_strcasecmp(source_p->certfp, oper_p->certfp)) | |
257 | { | |
258 | sendto_one_numeric(source_p, ERR_NOOPERHOST, form_str(ERR_NOOPERHOST)); | |
259 | ilog(L_FOPER, "FAILED OPER (%s) by (%s!%s@%s) (%s) -- client certificate fingerprint mismatch", | |
260 | parv[1], source_p->name, | |
261 | source_p->username, source_p->host, source_p->sockhost); | |
262 | ||
263 | if(ConfigFileEntry.failed_oper_notice) | |
264 | { | |
265 | sendto_realops_snomask(SNO_GENERAL, L_NETWIDE, | |
266 | "Failed OPER attempt - client certificate fingerprint mismatch by %s (%s@%s)", | |
267 | source_p->name, source_p->username, source_p->host); | |
268 | } | |
269 | return; | |
270 | } | |
271 | } | |
272 | ||
273 | if(generate_challenge(&challenge, &(source_p->localClient->challenge), oper_p->rsa_pubkey)) | |
274 | { | |
275 | char *chal = challenge; | |
276 | source_p->localClient->chal_time = rb_current_time(); | |
277 | for(;;) | |
278 | { | |
279 | cnt = rb_strlcpy(chal_line, chal, CHALLENGE_WIDTH); | |
280 | sendto_one(source_p, form_str(RPL_RSACHALLENGE2), me.name, source_p->name, chal_line); | |
281 | if(cnt >= CHALLENGE_WIDTH) | |
282 | chal += CHALLENGE_WIDTH - 1; | |
283 | else | |
284 | break; | |
285 | ||
286 | } | |
287 | sendto_one(source_p, form_str(RPL_ENDOFRSACHALLENGE2), | |
288 | me.name, source_p->name); | |
289 | rb_free(challenge); | |
290 | source_p->user->opername = rb_strdup(oper_p->name); | |
291 | } | |
292 | else | |
293 | sendto_one_notice(source_p, ":Failed to generate challenge."); | |
294 | } | |
295 | ||
296 | static bool | |
297 | generate_challenge(char **r_challenge, char **r_response, RSA * rsa) | |
298 | { | |
299 | SHA_CTX ctx; | |
300 | unsigned char secret[CHALLENGE_SECRET_LENGTH], *tmp; | |
301 | unsigned long length; | |
302 | unsigned long e = 0; | |
303 | unsigned long cnt = 0; | |
304 | int ret; | |
305 | ||
306 | if(!rsa) | |
307 | return false; | |
308 | if(rb_get_random(secret, CHALLENGE_SECRET_LENGTH)) | |
309 | { | |
310 | SHA1_Init(&ctx); | |
311 | SHA1_Update(&ctx, (uint8_t *)secret, CHALLENGE_SECRET_LENGTH); | |
312 | *r_response = rb_malloc(SHA_DIGEST_LENGTH); | |
313 | SHA1_Final((uint8_t *)*r_response, &ctx); | |
314 | ||
315 | length = RSA_size(rsa); | |
316 | tmp = rb_malloc(length); | |
317 | ret = RSA_public_encrypt(CHALLENGE_SECRET_LENGTH, secret, tmp, rsa, RSA_PKCS1_OAEP_PADDING); | |
318 | ||
319 | if(ret >= 0) | |
320 | { | |
321 | *r_challenge = (char *)rb_base64_encode(tmp, ret); | |
322 | rb_free(tmp); | |
323 | return true; | |
324 | } | |
325 | ||
326 | rb_free(tmp); | |
327 | rb_free(*r_response); | |
328 | *r_response = NULL; | |
329 | } | |
330 | ||
331 | ERR_load_crypto_strings(); | |
332 | while ((cnt < 100) && (e = ERR_get_error())) | |
333 | { | |
334 | ilog(L_MAIN, "SSL error: %s", ERR_error_string(e, 0)); | |
335 | cnt++; | |
336 | } | |
337 | ||
338 | return false; | |
339 | } | |
340 | ||
341 | #endif /* HAVE_LIBCRYPTO */ |