Commit | Line | Data |
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981a9fad | 1 | /* $Cambridge: exim/src/src/auths/dovecot.c,v 1.12 2010/03/05 16:11:11 nm4 Exp $ */ |
14aa5a05 PH |
2 | |
3 | /* | |
4 | * Copyright (c) 2004 Andrey Panin <pazke@donpac.ru> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published | |
8 | * by the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | */ | |
11 | ||
57c2c631 PH |
12 | /* A number of modifications have been made to the original code. Originally I |
13 | commented them specially, but now they are getting quite extensive, so I have | |
14 | ceased doing that. The biggest change is to use unbuffered I/O on the socket | |
15 | because using C buffered I/O gives problems on some operating systems. PH */ | |
16 | ||
14aa5a05 PH |
17 | #include "../exim.h" |
18 | #include "dovecot.h" | |
19 | ||
20 | #define VERSION_MAJOR 1 | |
21 | #define VERSION_MINOR 0 | |
22 | ||
23 | /* Options specific to the authentication mechanism. */ | |
24 | optionlist auth_dovecot_options[] = { | |
25 | { | |
57c2c631 PH |
26 | "server_socket", |
27 | opt_stringptr, | |
28 | (void *)(offsetof(auth_dovecot_options_block, server_socket)) | |
14aa5a05 PH |
29 | }, |
30 | }; | |
31 | ||
32 | /* Size of the options list. An extern variable has to be used so that its | |
33 | address can appear in the tables drtables.c. */ | |
57c2c631 | 34 | |
14aa5a05 PH |
35 | int auth_dovecot_options_count = |
36 | sizeof(auth_dovecot_options) / sizeof(optionlist); | |
37 | ||
38 | /* Default private options block for the authentication method. */ | |
57c2c631 | 39 | |
14aa5a05 PH |
40 | auth_dovecot_options_block auth_dovecot_option_defaults = { |
41 | NULL, /* server_socket */ | |
42 | }; | |
43 | ||
57c2c631 PH |
44 | |
45 | /* Static variables for reading from the socket */ | |
46 | ||
47 | static uschar sbuffer[256]; | |
48 | static int sbp; | |
49 | ||
50 | ||
51 | ||
14aa5a05 PH |
52 | /************************************************* |
53 | * Initialization entry point * | |
54 | *************************************************/ | |
55 | ||
56 | /* Called for each instance, after its options have been read, to | |
57 | enable consistency checks to be done, or anything else that needs | |
58 | to be set up. */ | |
57c2c631 | 59 | |
14aa5a05 PH |
60 | void auth_dovecot_init(auth_instance *ablock) |
61 | { | |
62 | auth_dovecot_options_block *ob = | |
63 | (auth_dovecot_options_block *)(ablock->options_block); | |
64 | ||
65 | if (ablock->public_name == NULL) | |
66 | ablock->public_name = ablock->name; | |
67 | if (ob->server_socket != NULL) | |
68 | ablock->server = TRUE; | |
69 | ablock->client = FALSE; | |
70 | } | |
71 | ||
57c2c631 | 72 | static int strcut(uschar *str, uschar **ptrs, int nptrs) |
14aa5a05 | 73 | { |
57c2c631 | 74 | uschar *tmp = str; |
14aa5a05 PH |
75 | int n; |
76 | ||
77 | for (n = 0; n < nptrs; n++) | |
78 | ptrs[n] = NULL; | |
79 | n = 1; | |
80 | ||
81 | while (*str) { | |
82 | if (*str == '\t') { | |
83 | if (n <= nptrs) { | |
84 | *ptrs++ = tmp; | |
85 | tmp = str + 1; | |
86 | *str = 0; | |
87 | } | |
88 | n++; | |
89 | } | |
90 | str++; | |
91 | } | |
92 | ||
93 | if (n < nptrs) | |
94 | *ptrs = tmp; | |
95 | ||
96 | return n; | |
97 | } | |
98 | ||
99 | #define CHECK_COMMAND(str, arg_min, arg_max) do { \ | |
57c2c631 | 100 | if (strcmpic(US(str), args[0]) != 0) \ |
14aa5a05 PH |
101 | goto out; \ |
102 | if (nargs - 1 < (arg_min)) \ | |
103 | goto out; \ | |
6c588e74 | 104 | if ( (arg_max != -1) && (nargs - 1 > (arg_max)) ) \ |
14aa5a05 PH |
105 | goto out; \ |
106 | } while (0) | |
107 | ||
108 | #define OUT(msg) do { \ | |
109 | auth_defer_msg = (US msg); \ | |
110 | goto out; \ | |
111 | } while(0) | |
112 | ||
7befa435 PH |
113 | |
114 | ||
14aa5a05 | 115 | /************************************************* |
57c2c631 PH |
116 | * "fgets" to read directly from socket * |
117 | *************************************************/ | |
118 | ||
119 | /* Added by PH after a suggestion by Steve Usher because the previous use of | |
120 | C-style buffered I/O gave trouble. */ | |
121 | ||
122 | static uschar * | |
123 | dc_gets(uschar *s, int n, int fd) | |
124 | { | |
125 | int p = 0; | |
126 | int count = 0; | |
127 | ||
128 | for (;;) | |
129 | { | |
130 | if (sbp == 0) | |
131 | { | |
132 | sbp = read(fd, sbuffer, sizeof(sbuffer)); | |
133 | if (sbp == 0) { if (count == 0) return NULL; else break; } | |
51473862 | 134 | p = 0; |
57c2c631 PH |
135 | } |
136 | ||
137 | while (p < sbp) | |
138 | { | |
139 | if (count >= n - 1) break; | |
140 | s[count++] = sbuffer[p]; | |
141 | if (sbuffer[p++] == '\n') break; | |
142 | } | |
143 | ||
144 | memmove(sbuffer, sbuffer + p, sbp - p); | |
145 | sbp -= p; | |
146 | ||
147 | if (s[count-1] == '\n' || count >= n - 1) break; | |
148 | } | |
149 | ||
150 | s[count] = 0; | |
151 | return s; | |
152 | } | |
153 | ||
154 | ||
155 | ||
156 | ||
157 | /************************************************* | |
158 | * Server entry point * | |
159 | *************************************************/ | |
14aa5a05 PH |
160 | |
161 | int auth_dovecot_server(auth_instance *ablock, uschar *data) | |
162 | { | |
163 | auth_dovecot_options_block *ob = | |
164 | (auth_dovecot_options_block *)(ablock->options_block); | |
165 | struct sockaddr_un sa; | |
57c2c631 PH |
166 | uschar buffer[4096]; |
167 | uschar *args[8]; | |
7befa435 PH |
168 | uschar *auth_command; |
169 | uschar *auth_extra_data = US""; | |
14aa5a05 PH |
170 | int nargs, tmp; |
171 | int cuid = 0, cont = 1, found = 0, fd, ret = DEFER; | |
14aa5a05 PH |
172 | |
173 | HDEBUG(D_auth) debug_printf("dovecot authentication\n"); | |
174 | ||
175 | memset(&sa, 0, sizeof(sa)); | |
176 | sa.sun_family = AF_UNIX; | |
177 | ||
178 | /* This was the original code here: it is nonsense because strncpy() | |
179 | does not return an integer. I have converted this to use the function | |
180 | that formats and checks length. PH */ | |
181 | ||
182 | /* | |
183 | if (strncpy(sa.sun_path, ob->server_socket, sizeof(sa.sun_path)) < 0) { | |
184 | */ | |
185 | ||
186 | if (!string_format(US sa.sun_path, sizeof(sa.sun_path), "%s", | |
187 | ob->server_socket)) { | |
188 | auth_defer_msg = US"authentication socket path too long"; | |
189 | return DEFER; | |
190 | } | |
191 | ||
192 | auth_defer_msg = US"authentication socket connection error"; | |
193 | ||
194 | fd = socket(PF_UNIX, SOCK_STREAM, 0); | |
195 | if (fd < 0) | |
196 | return DEFER; | |
197 | ||
198 | if (connect(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) | |
199 | goto out; | |
200 | ||
14aa5a05 PH |
201 | auth_defer_msg = US"authentication socket protocol error"; |
202 | ||
57c2c631 | 203 | sbp = 0; /* Socket buffer pointer */ |
14aa5a05 | 204 | while (cont) { |
57c2c631 | 205 | if (dc_gets(buffer, sizeof(buffer), fd) == NULL) |
14aa5a05 PH |
206 | OUT("authentication socket read error or premature eof"); |
207 | ||
57c2c631 | 208 | buffer[Ustrlen(buffer) - 1] = 0; |
14aa5a05 PH |
209 | HDEBUG(D_auth) debug_printf("received: %s\n", buffer); |
210 | nargs = strcut(buffer, args, sizeof(args) / sizeof(args[0])); | |
211 | ||
981a9fad NM |
212 | /* Code below rewritten by Kirill Miazine (km@krot.org). Only check commands that |
213 | Exim will need. Original code also failed if Dovecot server sent unknown | |
214 | command. E.g. COOKIE in version 1.1 of the protocol would cause troubles. */ | |
215 | if (Ustrcmp(args[0], US"CUID") == 0) { | |
14aa5a05 | 216 | CHECK_COMMAND("CUID", 1, 1); |
57c2c631 | 217 | cuid = Uatoi(args[1]); |
981a9fad | 218 | } else if (Ustrcmp(args[0], US"VERSION") == 0) { |
14aa5a05 | 219 | CHECK_COMMAND("VERSION", 2, 2); |
57c2c631 | 220 | if (Uatoi(args[1]) != VERSION_MAJOR) |
14aa5a05 | 221 | OUT("authentication socket protocol version mismatch"); |
981a9fad NM |
222 | } else if (Ustrcmp(args[0], US"MECH") == 0) { |
223 | CHECK_COMMAND("MECH", 1, INT_MAX); | |
224 | if (strcmpic(US args[1], ablock->public_name) == 0) | |
225 | found = 1; | |
226 | } else if (Ustrcmp(args[0], US"DONE") == 0) { | |
227 | CHECK_COMMAND("DONE", 0, 0); | |
228 | cont = 0; | |
14aa5a05 PH |
229 | } |
230 | } | |
231 | ||
232 | if (!found) | |
233 | goto out; | |
234 | ||
7befa435 PH |
235 | /* Added by PH: data must not contain tab (as it is |
236 | b64 it shouldn't, but check for safety). */ | |
237 | ||
238 | if (Ustrchr(data, '\t') != NULL) { | |
239 | ret = FAIL; | |
240 | goto out; | |
241 | } | |
242 | ||
243 | /* Added by PH: extra fields when TLS is in use or if the TCP/IP | |
244 | connection is local. */ | |
245 | ||
246 | if (tls_cipher != NULL) | |
247 | auth_extra_data = string_sprintf("secured\t%s%s", | |
248 | tls_certificate_verified? "valid-client-cert" : "", | |
249 | tls_certificate_verified? "\t" : ""); | |
094a9ec3 PH |
250 | else if (interface_address != NULL && |
251 | Ustrcmp(sender_host_address, interface_address) == 0) | |
7befa435 PH |
252 | auth_extra_data = US"secured\t"; |
253 | ||
14aa5a05 PH |
254 | |
255 | /**************************************************************************** | |
256 | The code below was the original code here. It didn't work. A reading of the | |
257 | file auth-protocol.txt.gz that came with Dovecot 1.0_beta8 indicated that | |
7befa435 PH |
258 | this was not right. Maybe something changed. I changed it to move the |
259 | service indication into the AUTH command, and it seems to be better. PH | |
14aa5a05 PH |
260 | |
261 | fprintf(f, "VERSION\t%d\t%d\r\nSERVICE\tSMTP\r\nCPID\t%d\r\n" | |
262 | "AUTH\t%d\t%s\trip=%s\tlip=%s\tresp=%s\r\n", | |
263 | VERSION_MAJOR, VERSION_MINOR, getpid(), cuid, | |
264 | ablock->public_name, sender_host_address, interface_address, | |
265 | data ? (char *) data : ""); | |
7befa435 PH |
266 | |
267 | Subsequently, the command was modified to add "secured" and "valid-client- | |
268 | cert" when relevant. | |
6c588e74 NM |
269 | |
270 | The auth protocol is documented here: | |
271 | http://wiki.dovecot.org/Authentication_Protocol | |
14aa5a05 PH |
272 | ****************************************************************************/ |
273 | ||
7befa435 | 274 | auth_command = string_sprintf("VERSION\t%d\t%d\nCPID\t%d\n" |
deafd5b3 | 275 | "AUTH\t%d\t%s\tservice=smtp\t%srip=%s\tlip=%s\tnologin\tresp=%s\n", |
14aa5a05 | 276 | VERSION_MAJOR, VERSION_MINOR, getpid(), cuid, |
7befa435 PH |
277 | ablock->public_name, auth_extra_data, sender_host_address, |
278 | interface_address, data ? (char *) data : ""); | |
14aa5a05 | 279 | |
57c2c631 PH |
280 | if (write(fd, auth_command, Ustrlen(auth_command)) < 0) |
281 | HDEBUG(D_auth) debug_printf("error sending auth_command: %s\n", | |
282 | strerror(errno)); | |
283 | ||
7befa435 | 284 | HDEBUG(D_auth) debug_printf("sent: %s", auth_command); |
14aa5a05 PH |
285 | |
286 | while (1) { | |
57c2c631 | 287 | uschar *temp; |
6c588e74 NM |
288 | uschar *auth_id_pre = NULL; |
289 | int i; | |
290 | ||
57c2c631 | 291 | if (dc_gets(buffer, sizeof(buffer), fd) == NULL) { |
14aa5a05 PH |
292 | auth_defer_msg = US"authentication socket read error or premature eof"; |
293 | goto out; | |
294 | } | |
295 | ||
57c2c631 | 296 | buffer[Ustrlen(buffer) - 1] = 0; |
14aa5a05 PH |
297 | HDEBUG(D_auth) debug_printf("received: %s\n", buffer); |
298 | nargs = strcut(buffer, args, sizeof(args) / sizeof(args[0])); | |
299 | ||
57c2c631 | 300 | if (Uatoi(args[1]) != cuid) |
14aa5a05 PH |
301 | OUT("authentication socket connection id mismatch"); |
302 | ||
303 | switch (toupper(*args[0])) { | |
304 | case 'C': | |
305 | CHECK_COMMAND("CONT", 1, 2); | |
306 | ||
307 | tmp = auth_get_no64_data(&data, US args[2]); | |
308 | if (tmp != OK) { | |
309 | ret = tmp; | |
310 | goto out; | |
311 | } | |
312 | ||
7befa435 PH |
313 | /* Added by PH: data must not contain tab (as it is |
314 | b64 it shouldn't, but check for safety). */ | |
315 | ||
316 | if (Ustrchr(data, '\t') != NULL) { | |
317 | ret = FAIL; | |
318 | goto out; | |
319 | } | |
320 | ||
deafd5b3 | 321 | temp = string_sprintf("CONT\t%d\t%s\n", cuid, data); |
57c2c631 | 322 | if (write(fd, temp, Ustrlen(temp)) < 0) |
14aa5a05 | 323 | OUT("authentication socket write error"); |
14aa5a05 PH |
324 | break; |
325 | ||
326 | case 'F': | |
6c588e74 | 327 | CHECK_COMMAND("FAIL", 1, -1); |
14aa5a05 | 328 | |
6c588e74 NM |
329 | for (i=2; (i<nargs) && (auth_id_pre == NULL); i++) |
330 | { | |
331 | if ( Ustrncmp(args[i], US"user=", 5) == 0 ) | |
332 | { | |
333 | auth_id_pre = args[i]+5; | |
f0872424 | 334 | expand_nstring[1] = auth_vars[0] = |
6c588e74 NM |
335 | string_copy(auth_id_pre); /* PH */ |
336 | expand_nlength[1] = Ustrlen(auth_id_pre); | |
14aa5a05 PH |
337 | expand_nmax = 1; |
338 | } | |
339 | } | |
340 | ||
341 | ret = FAIL; | |
342 | goto out; | |
343 | ||
344 | case 'O': | |
6c588e74 NM |
345 | CHECK_COMMAND("OK", 2, -1); |
346 | ||
347 | /* | |
348 | * Search for the "user=$USER" string in the args array | |
349 | * and return the proper value. | |
350 | */ | |
351 | for (i=2; (i<nargs) && (auth_id_pre == NULL); i++) | |
14aa5a05 | 352 | { |
6c588e74 NM |
353 | if ( Ustrncmp(args[i], US"user=", 5) == 0 ) |
354 | { | |
355 | auth_id_pre = args[i]+5; | |
356 | expand_nstring[1] = auth_vars[0] = | |
357 | string_copy(auth_id_pre); /* PH */ | |
358 | expand_nlength[1] = Ustrlen(auth_id_pre); | |
359 | expand_nmax = 1; | |
360 | } | |
14aa5a05 | 361 | } |
6c588e74 NM |
362 | |
363 | if (auth_id_pre == NULL) | |
364 | OUT("authentication socket protocol error, username missing"); | |
365 | ||
14aa5a05 PH |
366 | ret = OK; |
367 | /* fallthrough */ | |
368 | ||
369 | default: | |
370 | goto out; | |
371 | } | |
372 | } | |
373 | ||
57c2c631 | 374 | out: |
3f0da4d0 NM |
375 | /* close the socket used by dovecot */ |
376 | if (fd >= 0) | |
377 | close(fd); | |
16ff981e PH |
378 | |
379 | /* Expand server_condition as an authorization check */ | |
380 | return (ret == OK)? auth_check_serv_cond(ablock) : ret; | |
14aa5a05 | 381 | } |