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