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1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ | |
2 | ||
3 | #include <libintl.h> | |
4 | #include <security/pam_ext.h> | |
5 | #include <security/pam_misc.h> | |
6 | #include <security/pam_modules.h> | |
7 | ||
8 | #include "sd-bus.h" | |
9 | ||
10 | #include "alloc-util.h" | |
11 | #include "bus-common-errors.h" | |
12 | #include "bus-locator.h" | |
13 | #include "bus-util.h" | |
14 | #include "fd-util.h" | |
15 | #include "home-util.h" | |
16 | #include "locale-util.h" | |
17 | #include "pam-util.h" | |
18 | #include "parse-util.h" | |
19 | #include "path-util.h" | |
20 | #include "string-util.h" | |
21 | #include "strv.h" | |
22 | #include "time-util.h" | |
23 | #include "user-record.h" | |
24 | #include "user-record-util.h" | |
25 | #include "user-util.h" | |
26 | ||
27 | typedef enum AcquireHomeFlags { | |
28 | ACQUIRE_MUST_AUTHENTICATE = 1 << 0, | |
29 | ACQUIRE_PLEASE_SUSPEND = 1 << 1, | |
30 | ACQUIRE_REF_ANYWAY = 1 << 2, | |
31 | } AcquireHomeFlags; | |
32 | ||
33 | static int parse_argv( | |
34 | pam_handle_t *handle, | |
35 | int argc, const char **argv, | |
36 | AcquireHomeFlags *flags, | |
37 | bool *debug) { | |
38 | ||
39 | assert(argc >= 0); | |
40 | assert(argc == 0 || argv); | |
41 | ||
42 | for (int i = 0; i < argc; i++) { | |
43 | const char *v; | |
44 | ||
45 | if ((v = startswith(argv[i], "suspend="))) { | |
46 | int k; | |
47 | ||
48 | k = parse_boolean(v); | |
49 | if (k < 0) | |
50 | pam_syslog(handle, LOG_WARNING, "Failed to parse suspend= argument, ignoring: %s", v); | |
51 | else if (flags) | |
52 | SET_FLAG(*flags, ACQUIRE_PLEASE_SUSPEND, k); | |
53 | ||
54 | } else if (streq(argv[i], "debug")) { | |
55 | if (debug) | |
56 | *debug = true; | |
57 | ||
58 | } else if ((v = startswith(argv[i], "debug="))) { | |
59 | int k; | |
60 | k = parse_boolean(v); | |
61 | if (k < 0) | |
62 | pam_syslog(handle, LOG_WARNING, "Failed to parse debug= argument, ignoring: %s", v); | |
63 | else if (debug) | |
64 | *debug = k; | |
65 | ||
66 | } else | |
67 | pam_syslog(handle, LOG_WARNING, "Unknown parameter '%s', ignoring", argv[i]); | |
68 | } | |
69 | ||
70 | return 0; | |
71 | } | |
72 | ||
73 | static int parse_env( | |
74 | pam_handle_t *handle, | |
75 | AcquireHomeFlags *flags) { | |
76 | ||
77 | const char *v; | |
78 | int r; | |
79 | ||
80 | /* Let's read the suspend setting from an env var in addition to the PAM command line. That makes it | |
81 | * easy to declare the features of a display manager in code rather than configuration, and this is | |
82 | * really a feature of code */ | |
83 | ||
84 | v = pam_getenv(handle, "SYSTEMD_HOME_SUSPEND"); | |
85 | if (!v) { | |
86 | /* Also check the process env block, so that people can control this via an env var from the | |
87 | * outside of our process. */ | |
88 | v = secure_getenv("SYSTEMD_HOME_SUSPEND"); | |
89 | if (!v) | |
90 | return 0; | |
91 | } | |
92 | ||
93 | r = parse_boolean(v); | |
94 | if (r < 0) | |
95 | pam_syslog(handle, LOG_WARNING, "Failed to parse $SYSTEMD_HOME_SUSPEND argument, ignoring: %s", v); | |
96 | else if (flags) | |
97 | SET_FLAG(*flags, ACQUIRE_PLEASE_SUSPEND, r); | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | static int acquire_user_record( | |
103 | pam_handle_t *handle, | |
104 | const char *username, | |
105 | bool debug, | |
106 | UserRecord **ret_record, | |
107 | PamBusData **bus_data) { | |
108 | ||
109 | int r; | |
110 | ||
111 | assert(handle); | |
112 | ||
113 | if (!username) { | |
114 | r = pam_get_user(handle, &username, NULL); | |
115 | if (r != PAM_SUCCESS) | |
116 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to get user name: @PAMERR@"); | |
117 | if (isempty(username)) | |
118 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_SERVICE_ERR, "User name not set."); | |
119 | } | |
120 | ||
121 | /* Possibly split out the area name */ | |
122 | _cleanup_free_ char *username_without_area = NULL, *area = NULL; | |
123 | const char *carea = strrchr(username, '%'); | |
124 | if (carea && (filename_is_valid(carea + 1) || isempty(carea + 1))) { | |
125 | username_without_area = strndup(username, carea - username); | |
126 | if (!username_without_area) | |
127 | return pam_log_oom(handle); | |
128 | ||
129 | username = username_without_area; | |
130 | area = strdup(carea + 1); | |
131 | if (!area) | |
132 | return pam_log_oom(handle); | |
133 | } | |
134 | ||
135 | /* Let's bypass all IPC complexity for the two user names we know for sure we don't manage, and for | |
136 | * user names we don't consider valid. */ | |
137 | if (STR_IN_SET(username, "root", NOBODY_USER_NAME) || !valid_user_group_name(username, 0)) | |
138 | return PAM_USER_UNKNOWN; | |
139 | ||
140 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; | |
141 | _cleanup_(sd_json_variant_unrefp) sd_json_variant *v = NULL; | |
142 | _cleanup_(user_record_unrefp) UserRecord *ur = NULL; | |
143 | const char *json = NULL; | |
144 | bool fresh_data; | |
145 | ||
146 | /* We cache the user record in the PAM context. We use a field name that includes the username, since | |
147 | * clients might change the user name associated with a PAM context underneath us. Notably, 'sudo' | |
148 | * creates a single PAM context and first authenticates it with the user set to the originating user, | |
149 | * then updates the user for the destination user and issues the session stack with the same PAM | |
150 | * context. We thus must be prepared that the user record changes between calls and we keep any | |
151 | * caching separate. */ | |
152 | _cleanup_free_ char *homed_field = strjoin("systemd-home-user-record-", username); | |
153 | if (!homed_field) | |
154 | return pam_log_oom(handle); | |
155 | ||
156 | /* Let's use the cache, so that we can share it between the session and the authentication hooks */ | |
157 | r = pam_get_data(handle, homed_field, (const void**) &json); | |
158 | if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) | |
159 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to get PAM user record data: @PAMERR@"); | |
160 | if (r == PAM_SUCCESS && json) { | |
161 | /* We determined earlier that this is not a homed user? Then exit early. (We use -1 as | |
162 | * negative cache indicator) */ | |
163 | if (json == POINTER_MAX) | |
164 | return PAM_USER_UNKNOWN; | |
165 | ||
166 | fresh_data = false; | |
167 | } else { | |
168 | _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; | |
169 | _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; | |
170 | ||
171 | r = pam_acquire_bus_connection(handle, "pam-systemd-home", debug, &bus, bus_data); | |
172 | if (r != PAM_SUCCESS) | |
173 | return r; | |
174 | ||
175 | r = bus_call_method(bus, bus_home_mgr, "GetUserRecordByName", &error, &reply, "s", username); | |
176 | if (r < 0) { | |
177 | if (bus_error_is_unknown_service(&error)) { | |
178 | pam_debug_syslog(handle, debug, | |
179 | "systemd-homed is not available: %s", | |
180 | bus_error_message(&error, r)); | |
181 | goto user_unknown; | |
182 | } | |
183 | ||
184 | if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_HOME)) { | |
185 | pam_debug_syslog(handle, debug, | |
186 | "Not a user managed by systemd-homed: %s", | |
187 | bus_error_message(&error, r)); | |
188 | goto user_unknown; | |
189 | } | |
190 | ||
191 | pam_syslog(handle, LOG_ERR, | |
192 | "Failed to query user record: %s", bus_error_message(&error, r)); | |
193 | return PAM_SERVICE_ERR; | |
194 | } | |
195 | ||
196 | r = sd_bus_message_read(reply, "sbo", &json, NULL, NULL); | |
197 | if (r < 0) | |
198 | return pam_bus_log_parse_error(handle, r); | |
199 | ||
200 | fresh_data = true; | |
201 | } | |
202 | ||
203 | r = sd_json_parse(json, /* flags= */ 0, &v, NULL, NULL); | |
204 | if (r < 0) | |
205 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to parse JSON user record: %m"); | |
206 | ||
207 | ur = user_record_new(); | |
208 | if (!ur) | |
209 | return pam_log_oom(handle); | |
210 | ||
211 | r = user_record_load(ur, v, USER_RECORD_LOAD_REFUSE_SECRET|USER_RECORD_PERMISSIVE); | |
212 | if (r < 0) | |
213 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to load user record: %m"); | |
214 | ||
215 | /* Safety check if cached record actually matches what we are looking for */ | |
216 | if (!user_record_matches_user_name(ur, username)) | |
217 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_SERVICE_ERR, | |
218 | "Acquired user record does not match user name."); | |
219 | ||
220 | /* Update the 'username' pointer to point to our own record now. The pam_set_item() call below is | |
221 | * going to invalidate the old version after all */ | |
222 | username = ur->user_name; | |
223 | ||
224 | /* We passed all checks. Let's now make sure the rest of the PAM stack continues with the primary, | |
225 | * normalized name of the user record (i.e. not an alias or so). */ | |
226 | r = pam_set_item(handle, PAM_USER, ur->user_name); | |
227 | if (r != PAM_SUCCESS) | |
228 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
229 | "Failed to update username PAM item to '%s': @PAMERR@", ur->user_name); | |
230 | ||
231 | /* Everything seems to be good, let's cache this data now */ | |
232 | if (fresh_data) { | |
233 | /* First copy: for the homed-specific data field, i.e. where we know the user record is from | |
234 | * homed */ | |
235 | _cleanup_free_ char *json_copy = strdup(json); | |
236 | if (!json_copy) | |
237 | return pam_log_oom(handle); | |
238 | ||
239 | r = pam_set_data(handle, homed_field, json_copy, pam_cleanup_free); | |
240 | if (r != PAM_SUCCESS) | |
241 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
242 | "Failed to set PAM user record data '%s': @PAMERR@", homed_field); | |
243 | ||
244 | /* Take a second copy: for the generic data field, the one which we share with | |
245 | * pam_systemd. While we insist on only reusing homed records, pam_systemd is fine with homed | |
246 | * and non-homed user records. */ | |
247 | json_copy = strdup(json); | |
248 | if (!json_copy) | |
249 | return pam_log_oom(handle); | |
250 | ||
251 | _cleanup_free_ char *generic_field = strjoin("systemd-user-record-", username); | |
252 | if (!generic_field) | |
253 | return pam_log_oom(handle); | |
254 | ||
255 | r = pam_set_data(handle, generic_field, json_copy, pam_cleanup_free); | |
256 | if (r != PAM_SUCCESS) | |
257 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
258 | "Failed to set PAM user record data '%s': @PAMERR@", generic_field); | |
259 | ||
260 | TAKE_PTR(json_copy); | |
261 | } | |
262 | ||
263 | /* Let's store the area we parsed out of the name in an env var, so that pam_systemd later can honour it. */ | |
264 | if (area) { | |
265 | r = pam_misc_setenv(handle, "XDG_AREA", area, /* readonly= */ 0); | |
266 | if (r != PAM_SUCCESS) | |
267 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
268 | "Failed to set environment variable $XDG_AREA to '%s': @PAMERR@", area); | |
269 | } | |
270 | ||
271 | if (ret_record) | |
272 | *ret_record = TAKE_PTR(ur); | |
273 | ||
274 | return PAM_SUCCESS; | |
275 | ||
276 | user_unknown: | |
277 | /* Cache this, so that we don't check again */ | |
278 | r = pam_set_data(handle, homed_field, POINTER_MAX, NULL); | |
279 | if (r != PAM_SUCCESS) | |
280 | pam_syslog_pam_error(handle, LOG_ERR, r, | |
281 | "Failed to set PAM user record data '%s' to invalid, ignoring: @PAMERR@", | |
282 | homed_field); | |
283 | ||
284 | return PAM_USER_UNKNOWN; | |
285 | } | |
286 | ||
287 | static int release_user_record(pam_handle_t *handle, const char *username) { | |
288 | _cleanup_free_ char *homed_field = NULL, *generic_field = NULL; | |
289 | int r, k; | |
290 | ||
291 | assert(handle); | |
292 | assert(username); | |
293 | ||
294 | homed_field = strjoin("systemd-home-user-record-", username); | |
295 | if (!homed_field) | |
296 | return pam_log_oom(handle); | |
297 | ||
298 | r = pam_set_data(handle, homed_field, NULL, NULL); | |
299 | if (r != PAM_SUCCESS) | |
300 | pam_syslog_pam_error(handle, LOG_ERR, r, | |
301 | "Failed to release PAM user record data '%s': @PAMERR@", homed_field); | |
302 | ||
303 | generic_field = strjoin("systemd-user-record-", username); | |
304 | if (!generic_field) | |
305 | return pam_log_oom(handle); | |
306 | ||
307 | k = pam_set_data(handle, generic_field, NULL, NULL); | |
308 | if (k != PAM_SUCCESS) | |
309 | pam_syslog_pam_error(handle, LOG_ERR, k, | |
310 | "Failed to release PAM user record data '%s': @PAMERR@", generic_field); | |
311 | ||
312 | return IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA) ? k : r; | |
313 | } | |
314 | ||
315 | static void cleanup_home_fd(pam_handle_t *handle, void *data, int error_status) { | |
316 | safe_close(PTR_TO_FD(data)); | |
317 | } | |
318 | ||
319 | static int handle_generic_user_record_error( | |
320 | pam_handle_t *handle, | |
321 | const char *user_name, | |
322 | UserRecord *secret, | |
323 | int ret, | |
324 | const sd_bus_error *error, | |
325 | bool debug) { | |
326 | ||
327 | int r; | |
328 | ||
329 | assert(user_name); | |
330 | assert(error); | |
331 | ||
332 | /* Logs about all errors, except for PAM_CONV_ERR, i.e. when requesting more info failed. */ | |
333 | ||
334 | if (sd_bus_error_has_name(error, BUS_ERROR_HOME_ABSENT)) { | |
335 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, | |
336 | _("Home of user %s is currently absent, please plug in the necessary storage device or backing file system."), user_name); | |
337 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_PERM_DENIED, | |
338 | "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); | |
339 | ||
340 | } else if (sd_bus_error_has_name(error, BUS_ERROR_AUTHENTICATION_LIMIT_HIT)) { | |
341 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Too frequent login attempts for user %s, try again later."), user_name); | |
342 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_MAXTRIES, | |
343 | "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); | |
344 | ||
345 | } else if (sd_bus_error_has_name(error, BUS_ERROR_BAD_PASSWORD)) { | |
346 | _cleanup_(erase_and_freep) char *newp = NULL; | |
347 | ||
348 | assert(secret); | |
349 | ||
350 | /* This didn't work? Ask for an (additional?) password */ | |
351 | ||
352 | if (strv_isempty(secret->password)) | |
353 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Password: ")); | |
354 | else { | |
355 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Password incorrect or not sufficient for authentication of user %s."), user_name); | |
356 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Sorry, try again: ")); | |
357 | } | |
358 | if (r != PAM_SUCCESS) | |
359 | return PAM_CONV_ERR; /* no logging here */ | |
360 | ||
361 | if (isempty(newp)) { | |
362 | pam_debug_syslog(handle, debug, "Password request aborted."); | |
363 | return PAM_AUTHTOK_ERR; | |
364 | } | |
365 | ||
366 | r = user_record_set_password(secret, STRV_MAKE(newp), true); | |
367 | if (r < 0) | |
368 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store password: %m"); | |
369 | ||
370 | } else if (sd_bus_error_has_name(error, BUS_ERROR_BAD_RECOVERY_KEY)) { | |
371 | _cleanup_(erase_and_freep) char *newp = NULL; | |
372 | ||
373 | assert(secret); | |
374 | ||
375 | /* Hmm, homed asks for recovery key (because no regular password is defined maybe)? Provide it. */ | |
376 | ||
377 | if (strv_isempty(secret->password)) | |
378 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Recovery key: ")); | |
379 | else { | |
380 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Password/recovery key incorrect or not sufficient for authentication of user %s."), user_name); | |
381 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Sorry, reenter recovery key: ")); | |
382 | } | |
383 | if (r != PAM_SUCCESS) | |
384 | return PAM_CONV_ERR; /* no logging here */ | |
385 | ||
386 | if (isempty(newp)) { | |
387 | pam_debug_syslog(handle, debug, "Recovery key request aborted."); | |
388 | return PAM_AUTHTOK_ERR; | |
389 | } | |
390 | ||
391 | r = user_record_set_password(secret, STRV_MAKE(newp), true); | |
392 | if (r < 0) | |
393 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store recovery key: %m"); | |
394 | ||
395 | } else if (sd_bus_error_has_name(error, BUS_ERROR_BAD_PASSWORD_AND_NO_TOKEN)) { | |
396 | _cleanup_(erase_and_freep) char *newp = NULL; | |
397 | ||
398 | assert(secret); | |
399 | ||
400 | if (strv_isempty(secret->password)) { | |
401 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Security token of user %s not inserted."), user_name); | |
402 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Try again with password: ")); | |
403 | } else { | |
404 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Password incorrect or not sufficient, and configured security token of user %s not inserted."), user_name); | |
405 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Try again with password: ")); | |
406 | } | |
407 | if (r != PAM_SUCCESS) | |
408 | return PAM_CONV_ERR; /* no logging here */ | |
409 | ||
410 | if (isempty(newp)) { | |
411 | pam_debug_syslog(handle, debug, "Password request aborted."); | |
412 | return PAM_AUTHTOK_ERR; | |
413 | } | |
414 | ||
415 | r = user_record_set_password(secret, STRV_MAKE(newp), true); | |
416 | if (r < 0) | |
417 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store password: %m"); | |
418 | ||
419 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_PIN_NEEDED)) { | |
420 | _cleanup_(erase_and_freep) char *newp = NULL; | |
421 | ||
422 | assert(secret); | |
423 | ||
424 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Security token PIN: ")); | |
425 | if (r != PAM_SUCCESS) | |
426 | return PAM_CONV_ERR; /* no logging here */ | |
427 | ||
428 | if (isempty(newp)) { | |
429 | pam_debug_syslog(handle, debug, "PIN request aborted."); | |
430 | return PAM_AUTHTOK_ERR; | |
431 | } | |
432 | ||
433 | r = user_record_set_token_pin(secret, STRV_MAKE(newp), false); | |
434 | if (r < 0) | |
435 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store PIN: %m"); | |
436 | ||
437 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_PROTECTED_AUTHENTICATION_PATH_NEEDED)) { | |
438 | ||
439 | assert(secret); | |
440 | ||
441 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Please authenticate physically on security token of user %s."), user_name); | |
442 | ||
443 | r = user_record_set_pkcs11_protected_authentication_path_permitted(secret, true); | |
444 | if (r < 0) | |
445 | return pam_syslog_errno(handle, LOG_ERR, r, | |
446 | "Failed to set PKCS#11 protected authentication path permitted flag: %m"); | |
447 | ||
448 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_USER_PRESENCE_NEEDED)) { | |
449 | ||
450 | assert(secret); | |
451 | ||
452 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Please confirm presence on security token of user %s."), user_name); | |
453 | ||
454 | r = user_record_set_fido2_user_presence_permitted(secret, true); | |
455 | if (r < 0) | |
456 | return pam_syslog_errno(handle, LOG_ERR, r, | |
457 | "Failed to set FIDO2 user presence permitted flag: %m"); | |
458 | ||
459 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_USER_VERIFICATION_NEEDED)) { | |
460 | ||
461 | assert(secret); | |
462 | ||
463 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Please verify user on security token of user %s."), user_name); | |
464 | ||
465 | r = user_record_set_fido2_user_verification_permitted(secret, true); | |
466 | if (r < 0) | |
467 | return pam_syslog_errno(handle, LOG_ERR, r, | |
468 | "Failed to set FIDO2 user verification permitted flag: %m"); | |
469 | ||
470 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_PIN_LOCKED)) { | |
471 | ||
472 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Security token PIN is locked, please unlock it first. (Hint: Removal and re-insertion might suffice.)")); | |
473 | return PAM_SERVICE_ERR; | |
474 | ||
475 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN)) { | |
476 | _cleanup_(erase_and_freep) char *newp = NULL; | |
477 | ||
478 | assert(secret); | |
479 | ||
480 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Security token PIN incorrect for user %s."), user_name); | |
481 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Sorry, retry security token PIN: ")); | |
482 | if (r != PAM_SUCCESS) | |
483 | return PAM_CONV_ERR; /* no logging here */ | |
484 | ||
485 | if (isempty(newp)) { | |
486 | pam_debug_syslog(handle, debug, "PIN request aborted."); | |
487 | return PAM_AUTHTOK_ERR; | |
488 | } | |
489 | ||
490 | r = user_record_set_token_pin(secret, STRV_MAKE(newp), false); | |
491 | if (r < 0) | |
492 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store PIN: %m"); | |
493 | ||
494 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN_FEW_TRIES_LEFT)) { | |
495 | _cleanup_(erase_and_freep) char *newp = NULL; | |
496 | ||
497 | assert(secret); | |
498 | ||
499 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Security token PIN of user %s incorrect (only a few tries left!)"), user_name); | |
500 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Sorry, retry security token PIN: ")); | |
501 | if (r != PAM_SUCCESS) | |
502 | return PAM_CONV_ERR; /* no logging here */ | |
503 | ||
504 | if (isempty(newp)) { | |
505 | pam_debug_syslog(handle, debug, "PIN request aborted."); | |
506 | return PAM_AUTHTOK_ERR; | |
507 | } | |
508 | ||
509 | r = user_record_set_token_pin(secret, STRV_MAKE(newp), false); | |
510 | if (r < 0) | |
511 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store PIN: %m"); | |
512 | ||
513 | } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN_ONE_TRY_LEFT)) { | |
514 | _cleanup_(erase_and_freep) char *newp = NULL; | |
515 | ||
516 | assert(secret); | |
517 | ||
518 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Security token PIN of user %s incorrect (only one try left!)"), user_name); | |
519 | r = pam_prompt_graceful(handle, PAM_PROMPT_ECHO_OFF, &newp, _("Sorry, retry security token PIN: ")); | |
520 | if (r != PAM_SUCCESS) | |
521 | return PAM_CONV_ERR; /* no logging here */ | |
522 | ||
523 | if (isempty(newp)) { | |
524 | pam_debug_syslog(handle, debug, "PIN request aborted."); | |
525 | return PAM_AUTHTOK_ERR; | |
526 | } | |
527 | ||
528 | r = user_record_set_token_pin(secret, STRV_MAKE(newp), false); | |
529 | if (r < 0) | |
530 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store PIN: %m"); | |
531 | ||
532 | } else | |
533 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_SERVICE_ERR, | |
534 | "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); | |
535 | ||
536 | return PAM_SUCCESS; | |
537 | } | |
538 | ||
539 | static int acquire_home( | |
540 | pam_handle_t *handle, | |
541 | AcquireHomeFlags flags, | |
542 | bool debug, | |
543 | PamBusData **bus_data) { | |
544 | ||
545 | _cleanup_(user_record_unrefp) UserRecord *ur = NULL, *secret = NULL; | |
546 | bool do_auth = FLAGS_SET(flags, ACQUIRE_MUST_AUTHENTICATE), home_not_active = false, home_locked = false, unrestricted = false; | |
547 | _cleanup_close_ int acquired_fd = -EBADF; | |
548 | _cleanup_free_ char *fd_field = NULL; | |
549 | const void *home_fd_ptr = NULL; | |
550 | const char *username = NULL; | |
551 | unsigned n_attempts = 0; | |
552 | int r; | |
553 | ||
554 | assert(handle); | |
555 | ||
556 | /* This acquires a reference to a home directory in the following ways: | |
557 | * | |
558 | * 1. If ACQUIRE_MUST_AUTHENTICATE is not set, it tries to call RefHome() first — which will get us a | |
559 | * reference to the home without authentication (which will work for homes that are not encrypted, | |
560 | * or that already are activated). If this works, we are done. Yay! | |
561 | * | |
562 | * 2. Otherwise, we'll call AcquireHome() — which will try to activate the home getting us a | |
563 | * reference. If this works, we are done. Yay! | |
564 | * | |
565 | * 3. if ACQUIRE_REF_ANYWAY is set, we'll call RefHomeUnrestricted() — which will give us a reference | |
566 | * in any case (even if the activation failed!). | |
567 | * | |
568 | * The idea is that ACQUIRE_MUST_AUTHENTICATE is off for the PAM session hooks (since for those | |
569 | * authentication doesn't matter), and on for the PAM authentication hooks (since for those | |
570 | * authentication is essential). And ACQUIRE_REF_ANYWAY should be set if we are pretty sure that we | |
571 | * can later activate the home directory via our fallback shell logic, and hence are OK if we can't | |
572 | * activate things here. Usecase for that are SSH logins where SSH does the authentication and thus | |
573 | * only the session hooks are called. But from the session hooks SSH doesn't allow asking questions, | |
574 | * hence we simply allow the login attempt to continue but then invoke our fallback shell that will | |
575 | * prompt the user for the missing unlock credentials, and then chainload the real shell. | |
576 | */ | |
577 | ||
578 | r = pam_get_user(handle, &username, NULL); | |
579 | if (r != PAM_SUCCESS) | |
580 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to get user name: @PAMERR@"); | |
581 | if (isempty(username)) | |
582 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_SERVICE_ERR, "User name not set."); | |
583 | ||
584 | /* If we already have acquired the fd, let's shortcut this */ | |
585 | fd_field = strjoin("systemd-home-fd-", username); | |
586 | if (!fd_field) | |
587 | return pam_log_oom(handle); | |
588 | ||
589 | r = pam_get_data(handle, fd_field, &home_fd_ptr); | |
590 | if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) | |
591 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
592 | "Failed to retrieve PAM home reference fd: @PAMERR@"); | |
593 | if (r == PAM_SUCCESS && PTR_TO_FD(home_fd_ptr) >= 0) | |
594 | return PAM_SUCCESS; | |
595 | ||
596 | r = acquire_user_record(handle, username, debug, &ur, bus_data); | |
597 | if (r != PAM_SUCCESS) | |
598 | return r; | |
599 | ||
600 | /* Implement our own retry loop here instead of relying on the PAM client's one. That's because it | |
601 | * might happen that the record we stored on the host does not match the encryption password of the | |
602 | * LUKS image in case the image was used in a different system where the password was changed. In | |
603 | * that case it will happen that the LUKS password and the host password are different, and we handle | |
604 | * that by collecting and passing multiple passwords in that case. Hence we treat bad passwords as a | |
605 | * request to collect one more password and pass the new and all previously used passwords again. */ | |
606 | ||
607 | _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; | |
608 | r = pam_acquire_bus_connection(handle, "pam-systemd-home", debug, &bus, bus_data); | |
609 | if (r != PAM_SUCCESS) | |
610 | return r; | |
611 | ||
612 | for (;;) { | |
613 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL, *reply = NULL; | |
614 | _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; | |
615 | const char *method = NULL; | |
616 | ||
617 | if (do_auth && !secret) { | |
618 | const char *cached_password = NULL; | |
619 | ||
620 | secret = user_record_new(); | |
621 | if (!secret) | |
622 | return pam_log_oom(handle); | |
623 | ||
624 | /* If there's already a cached password, use it. But if not let's authenticate | |
625 | * without anything, maybe some other authentication mechanism systemd-homed | |
626 | * implements (such as PKCS#11) allows us to authenticate without anything else. */ | |
627 | r = pam_get_item(handle, PAM_AUTHTOK, (const void**) &cached_password); | |
628 | if (!IN_SET(r, PAM_BAD_ITEM, PAM_SUCCESS)) | |
629 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
630 | "Failed to get cached password: @PAMERR@"); | |
631 | ||
632 | if (!isempty(cached_password)) { | |
633 | r = user_record_set_password(secret, STRV_MAKE(cached_password), true); | |
634 | if (r < 0) | |
635 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store password: %m"); | |
636 | } | |
637 | } | |
638 | ||
639 | if (do_auth) | |
640 | method = "AcquireHome"; /* If we shall authenticate no matter what */ | |
641 | else if (unrestricted) | |
642 | method = "RefHomeUnrestricted"; /* If we shall get a ref no matter what */ | |
643 | else | |
644 | method = "RefHome"; /* If we shall get a ref (if possible) */ | |
645 | ||
646 | r = bus_message_new_method_call(bus, &m, bus_home_mgr, method); | |
647 | if (r < 0) | |
648 | return pam_bus_log_create_error(handle, r); | |
649 | ||
650 | r = sd_bus_message_append(m, "s", ur->user_name); | |
651 | if (r < 0) | |
652 | return pam_bus_log_create_error(handle, r); | |
653 | ||
654 | if (do_auth) { | |
655 | r = bus_message_append_secret(m, secret); | |
656 | if (r < 0) | |
657 | return pam_bus_log_create_error(handle, r); | |
658 | } | |
659 | ||
660 | r = sd_bus_message_append(m, "b", FLAGS_SET(flags, ACQUIRE_PLEASE_SUSPEND)); | |
661 | if (r < 0) | |
662 | return pam_bus_log_create_error(handle, r); | |
663 | ||
664 | r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, &reply); | |
665 | if (r < 0) { | |
666 | if (sd_bus_error_has_names(&error, BUS_ERROR_HOME_NOT_ACTIVE, BUS_ERROR_HOME_BUSY)) { | |
667 | /* Only on RefHome(): We can't access the home directory currently, unless | |
668 | * it's unlocked with a password. Hence, let's try this again, this time with | |
669 | * authentication. */ | |
670 | home_not_active = true; | |
671 | do_auth = true; | |
672 | } else if (sd_bus_error_has_name(&error, BUS_ERROR_HOME_LOCKED)) { | |
673 | home_locked = true; /* Similar */ | |
674 | do_auth = true; | |
675 | } else { | |
676 | r = handle_generic_user_record_error(handle, ur->user_name, secret, r, &error, debug); | |
677 | if (r == PAM_CONV_ERR) { | |
678 | /* Password/PIN prompts will fail in certain environments, for example when | |
679 | * we are called from OpenSSH's account or session hooks, or in systemd's | |
680 | * per-service PAM logic. In that case, print a friendly message and accept | |
681 | * failure. */ | |
682 | ||
683 | if (!FLAGS_SET(flags, ACQUIRE_REF_ANYWAY)) { | |
684 | if (home_not_active) | |
685 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Home of user %s is currently not active, please log in locally first."), ur->user_name); | |
686 | if (home_locked) | |
687 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Home of user %s is currently locked, please unlock locally first."), ur->user_name); | |
688 | ||
689 | if (FLAGS_SET(flags, ACQUIRE_MUST_AUTHENTICATE) || debug) | |
690 | pam_syslog(handle, FLAGS_SET(flags, ACQUIRE_MUST_AUTHENTICATE) ? LOG_ERR : LOG_DEBUG, "Failed to prompt for password/prompt."); | |
691 | ||
692 | return home_not_active || home_locked ? PAM_PERM_DENIED : PAM_CONV_ERR; | |
693 | } | |
694 | ||
695 | /* ref_anyway is true, hence let's now get a ref no matter what. */ | |
696 | unrestricted = true; | |
697 | do_auth = false; | |
698 | } else if (r != PAM_SUCCESS) | |
699 | return r; | |
700 | else | |
701 | do_auth = true; /* The issue was dealt with, some more information was collected. Let's try to authenticate, again. */ | |
702 | } | |
703 | } else { | |
704 | int fd; | |
705 | ||
706 | r = sd_bus_message_read(reply, "h", &fd); | |
707 | if (r < 0) | |
708 | return pam_bus_log_parse_error(handle, r); | |
709 | ||
710 | acquired_fd = fcntl(fd, F_DUPFD_CLOEXEC, 3); | |
711 | if (acquired_fd < 0) | |
712 | return pam_syslog_errno(handle, LOG_ERR, errno, | |
713 | "Failed to duplicate acquired fd: %m"); | |
714 | break; | |
715 | } | |
716 | ||
717 | if (++n_attempts >= 5) { | |
718 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, | |
719 | _("Too many unsuccessful login attempts for user %s, refusing."), ur->user_name); | |
720 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_MAXTRIES, | |
721 | "Failed to acquire home for user %s: %s", ur->user_name, bus_error_message(&error, r)); | |
722 | } | |
723 | } | |
724 | ||
725 | /* Later PAM modules may need the auth token, but only during pam_authenticate. */ | |
726 | if (FLAGS_SET(flags, ACQUIRE_MUST_AUTHENTICATE) && !strv_isempty(secret->password)) { | |
727 | r = pam_set_item(handle, PAM_AUTHTOK, *secret->password); | |
728 | if (r != PAM_SUCCESS) | |
729 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to set PAM auth token: @PAMERR@"); | |
730 | } | |
731 | ||
732 | r = pam_set_data(handle, fd_field, FD_TO_PTR(acquired_fd), cleanup_home_fd); | |
733 | if (r != PAM_SUCCESS) | |
734 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to set PAM bus data: @PAMERR@"); | |
735 | TAKE_FD(acquired_fd); | |
736 | ||
737 | if (do_auth) { | |
738 | /* We likely just activated the home directory, let's flush out the user record, since a | |
739 | * newer embedded user record might have been acquired from the activation. */ | |
740 | ||
741 | r = release_user_record(handle, ur->user_name); | |
742 | if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) | |
743 | return r; | |
744 | } | |
745 | ||
746 | /* If we didn't actually manage to unlock the home directory, then we rely on the fallback-shell to | |
747 | * unlock it for us. But until that happens we don't want that logind spawns the per-user service | |
748 | * manager for us (since it would see an inaccessible home directory). Hence set an environment | |
749 | * variable that pam_systemd looks for). */ | |
750 | if (unrestricted) { | |
751 | r = pam_putenv(handle, "XDG_SESSION_INCOMPLETE=1"); | |
752 | if (r != PAM_SUCCESS) | |
753 | return pam_syslog_pam_error(handle, LOG_WARNING, r, "Failed to set XDG_SESSION_INCOMPLETE= environment variable: @PAMERR@"); | |
754 | ||
755 | pam_syslog(handle, LOG_NOTICE, "Home for user %s acquired in incomplete mode, requires later activation.", ur->user_name); | |
756 | } else | |
757 | pam_syslog(handle, LOG_NOTICE, "Home for user %s successfully acquired.", ur->user_name); | |
758 | ||
759 | return PAM_SUCCESS; | |
760 | } | |
761 | ||
762 | static int release_home_fd(pam_handle_t *handle, const char *username) { | |
763 | _cleanup_free_ char *fd_field = NULL; | |
764 | const void *home_fd_ptr = NULL; | |
765 | int r; | |
766 | ||
767 | assert(handle); | |
768 | assert(username); | |
769 | ||
770 | fd_field = strjoin("systemd-home-fd-", username); | |
771 | if (!fd_field) | |
772 | return pam_log_oom(handle); | |
773 | ||
774 | r = pam_get_data(handle, fd_field, &home_fd_ptr); | |
775 | if (r == PAM_NO_MODULE_DATA || (r == PAM_SUCCESS && PTR_TO_FD(home_fd_ptr) < 0)) | |
776 | return PAM_NO_MODULE_DATA; | |
777 | if (r != PAM_SUCCESS) | |
778 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to retrieve PAM home reference fd: @PAMERR@"); | |
779 | ||
780 | r = pam_set_data(handle, fd_field, NULL, NULL); | |
781 | if (r != PAM_SUCCESS) | |
782 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to release PAM home reference fd: @PAMERR@"); | |
783 | ||
784 | return PAM_SUCCESS; | |
785 | } | |
786 | ||
787 | _public_ PAM_EXTERN int pam_sm_authenticate( | |
788 | pam_handle_t *handle, | |
789 | int sm_flags, | |
790 | int argc, const char **argv) { | |
791 | ||
792 | AcquireHomeFlags flags = 0; | |
793 | bool debug = false; | |
794 | ||
795 | pam_log_setup(); | |
796 | ||
797 | if (parse_env(handle, &flags) < 0) | |
798 | return PAM_AUTH_ERR; | |
799 | ||
800 | if (parse_argv(handle, | |
801 | argc, argv, | |
802 | &flags, | |
803 | &debug) < 0) | |
804 | return PAM_AUTH_ERR; | |
805 | ||
806 | pam_debug_syslog(handle, debug, "pam-systemd-homed authenticating"); | |
807 | ||
808 | return acquire_home(handle, ACQUIRE_MUST_AUTHENTICATE|flags, debug, /* bus_data= */ NULL); | |
809 | } | |
810 | ||
811 | _public_ PAM_EXTERN int pam_sm_setcred(pam_handle_t *pamh, int sm_flags, int argc, const char **argv) { | |
812 | return PAM_SUCCESS; | |
813 | } | |
814 | ||
815 | static int fallback_shell_can_work( | |
816 | pam_handle_t *handle, | |
817 | AcquireHomeFlags *flags) { | |
818 | ||
819 | const char *tty = NULL, *display = NULL; | |
820 | int r; | |
821 | ||
822 | assert(handle); | |
823 | assert(flags); | |
824 | ||
825 | r = pam_get_item_many( | |
826 | handle, | |
827 | PAM_TTY, &tty, | |
828 | PAM_XDISPLAY, &display); | |
829 | if (r != PAM_SUCCESS) | |
830 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to get PAM items: @PAMERR@"); | |
831 | ||
832 | /* The fallback shell logic only works on TTY logins, hence only allow it if there's no X11 display | |
833 | * set, and a TTY field is set that is neither "cron" (which is what crond sets, god knows why) not | |
834 | * contains a colon (which is what various graphical X11 logins do). Note that ssh sets the tty to | |
835 | * "ssh" here, which we allow (I mean, ssh is after all the primary reason we do all this). */ | |
836 | if (isempty(display) && | |
837 | tty && | |
838 | !strchr(tty, ':') && | |
839 | !streq(tty, "cron")) | |
840 | *flags |= ACQUIRE_REF_ANYWAY; /* Allow login even if we can only ref, not activate */ | |
841 | ||
842 | return PAM_SUCCESS; | |
843 | } | |
844 | ||
845 | _public_ PAM_EXTERN int pam_sm_open_session( | |
846 | pam_handle_t *handle, | |
847 | int sm_flags, | |
848 | int argc, const char **argv) { | |
849 | ||
850 | /* Let's release the D-Bus connection once this function exits, after all the session might live | |
851 | * quite a long time, and we are not going to process the bus connection in that time, so let's | |
852 | * better close before the daemon kicks us off because we are not processing anything. */ | |
853 | _cleanup_(pam_bus_data_disconnectp) PamBusData *d = NULL; | |
854 | AcquireHomeFlags flags = 0; | |
855 | bool debug = false; | |
856 | int r; | |
857 | ||
858 | pam_log_setup(); | |
859 | ||
860 | if (parse_env(handle, &flags) < 0) | |
861 | return PAM_SESSION_ERR; | |
862 | ||
863 | if (parse_argv(handle, | |
864 | argc, argv, | |
865 | &flags, | |
866 | &debug) < 0) | |
867 | return PAM_SESSION_ERR; | |
868 | ||
869 | pam_debug_syslog(handle, debug, "pam-systemd-homed session start"); | |
870 | ||
871 | r = fallback_shell_can_work(handle, &flags); | |
872 | if (r != PAM_SUCCESS) | |
873 | return r; | |
874 | ||
875 | /* Explicitly get saved PamBusData here. Otherwise, this function may succeed without setting 'd' | |
876 | * even if there is an opened sd-bus connection, and it will be leaked. See issue #31375. */ | |
877 | r = pam_get_bus_data(handle, "pam-systemd-home", &d); | |
878 | if (r != PAM_SUCCESS) | |
879 | return r; | |
880 | ||
881 | r = acquire_home(handle, flags, debug, &d); | |
882 | if (r == PAM_USER_UNKNOWN) /* Not managed by us? Don't complain. */ | |
883 | return PAM_SUCCESS; | |
884 | if (r != PAM_SUCCESS) | |
885 | return r; | |
886 | ||
887 | r = pam_putenv(handle, "SYSTEMD_HOME=1"); | |
888 | if (r != PAM_SUCCESS) | |
889 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
890 | "Failed to set PAM environment variable $SYSTEMD_HOME: @PAMERR@"); | |
891 | ||
892 | r = pam_putenv(handle, FLAGS_SET(flags, ACQUIRE_PLEASE_SUSPEND) ? "SYSTEMD_HOME_SUSPEND=1" : "SYSTEMD_HOME_SUSPEND=0"); | |
893 | if (r != PAM_SUCCESS) | |
894 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
895 | "Failed to set PAM environment variable $SYSTEMD_HOME_SUSPEND: @PAMERR@"); | |
896 | ||
897 | return PAM_SUCCESS; | |
898 | } | |
899 | ||
900 | _public_ PAM_EXTERN int pam_sm_close_session( | |
901 | pam_handle_t *handle, | |
902 | int sm_flags, | |
903 | int argc, const char **argv) { | |
904 | ||
905 | _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; | |
906 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; | |
907 | const char *username = NULL; | |
908 | bool debug = false; | |
909 | int r; | |
910 | ||
911 | pam_log_setup(); | |
912 | ||
913 | if (parse_argv(handle, | |
914 | argc, argv, | |
915 | NULL, | |
916 | &debug) < 0) | |
917 | return PAM_SESSION_ERR; | |
918 | ||
919 | pam_debug_syslog(handle, debug, "pam-systemd-homed session end"); | |
920 | ||
921 | r = pam_get_user(handle, &username, NULL); | |
922 | if (r != PAM_SUCCESS) | |
923 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to get user name: @PAMERR@"); | |
924 | if (isempty(username)) | |
925 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_SERVICE_ERR, "User name not set."); | |
926 | ||
927 | /* Let's explicitly drop the reference to the homed session, so that the subsequent ReleaseHome() | |
928 | * call will be able to do its thing. */ | |
929 | r = release_home_fd(handle, username); | |
930 | if (r == PAM_NO_MODULE_DATA) /* Nothing to do, we never acquired an fd */ | |
931 | return PAM_SUCCESS; | |
932 | if (r != PAM_SUCCESS) | |
933 | return r; | |
934 | ||
935 | _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; | |
936 | r = pam_acquire_bus_connection(handle, "pam-systemd-home", debug, &bus, NULL); | |
937 | if (r != PAM_SUCCESS) | |
938 | return r; | |
939 | ||
940 | r = bus_message_new_method_call(bus, &m, bus_home_mgr, "ReleaseHome"); | |
941 | if (r < 0) | |
942 | return pam_bus_log_create_error(handle, r); | |
943 | ||
944 | r = sd_bus_message_append(m, "s", username); | |
945 | if (r < 0) | |
946 | return pam_bus_log_create_error(handle, r); | |
947 | ||
948 | r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, NULL); | |
949 | if (r < 0) { | |
950 | if (!sd_bus_error_has_name(&error, BUS_ERROR_HOME_BUSY)) | |
951 | return pam_syslog_pam_error(handle, LOG_ERR, PAM_SESSION_ERR, | |
952 | "Failed to release user home: %s", bus_error_message(&error, r)); | |
953 | ||
954 | pam_syslog(handle, LOG_NOTICE, "Not deactivating home directory of %s, as it is still used.", username); | |
955 | } | |
956 | ||
957 | return PAM_SUCCESS; | |
958 | } | |
959 | ||
960 | _public_ PAM_EXTERN int pam_sm_acct_mgmt( | |
961 | pam_handle_t *handle, | |
962 | int sm_flags, | |
963 | int argc, | |
964 | const char **argv) { | |
965 | ||
966 | _cleanup_(user_record_unrefp) UserRecord *ur = NULL; | |
967 | AcquireHomeFlags flags = 0; | |
968 | bool debug = false; | |
969 | usec_t t; | |
970 | int r; | |
971 | ||
972 | pam_log_setup(); | |
973 | ||
974 | if (parse_env(handle, &flags) < 0) | |
975 | return PAM_AUTH_ERR; | |
976 | ||
977 | if (parse_argv(handle, | |
978 | argc, argv, | |
979 | &flags, | |
980 | &debug) < 0) | |
981 | return PAM_AUTH_ERR; | |
982 | ||
983 | pam_debug_syslog(handle, debug, "pam-systemd-homed account management"); | |
984 | ||
985 | r = fallback_shell_can_work(handle, &flags); | |
986 | if (r != PAM_SUCCESS) | |
987 | return r; | |
988 | ||
989 | r = acquire_home(handle, flags, debug, /* bus_data= */ NULL); | |
990 | if (r != PAM_SUCCESS) | |
991 | return r; | |
992 | ||
993 | r = acquire_user_record(handle, /* username= */ NULL, debug, &ur, /* bus_data= */ NULL); | |
994 | if (r != PAM_SUCCESS) | |
995 | return r; | |
996 | ||
997 | r = user_record_test_blocked(ur); | |
998 | switch (r) { | |
999 | ||
1000 | case -ESTALE: | |
1001 | pam_syslog(handle, LOG_WARNING, "User record for '%s' is newer than current system time, assuming incorrect system clock, allowing access.", ur->user_name); | |
1002 | break; | |
1003 | ||
1004 | case -ENOLCK: | |
1005 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("User record is blocked, prohibiting access.")); | |
1006 | return PAM_ACCT_EXPIRED; | |
1007 | ||
1008 | case -EL2HLT: | |
1009 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("User record is not valid yet, prohibiting access.")); | |
1010 | return PAM_ACCT_EXPIRED; | |
1011 | ||
1012 | case -EL3HLT: | |
1013 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("User record is not valid anymore, prohibiting access.")); | |
1014 | return PAM_ACCT_EXPIRED; | |
1015 | ||
1016 | default: | |
1017 | if (r < 0) { | |
1018 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("User record not valid, prohibiting access.")); | |
1019 | return PAM_ACCT_EXPIRED; | |
1020 | } | |
1021 | } | |
1022 | ||
1023 | t = user_record_ratelimit_next_try(ur); | |
1024 | if (t != USEC_INFINITY) { | |
1025 | usec_t n = now(CLOCK_REALTIME); | |
1026 | ||
1027 | if (t > n) { | |
1028 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Too many logins, try again in %s."), | |
1029 | FORMAT_TIMESPAN(t - n, USEC_PER_SEC)); | |
1030 | ||
1031 | return PAM_MAXTRIES; | |
1032 | } | |
1033 | } | |
1034 | ||
1035 | r = user_record_test_password_change_required(ur); | |
1036 | switch (r) { | |
1037 | ||
1038 | case -EKEYREVOKED: | |
1039 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Password change required.")); | |
1040 | return PAM_NEW_AUTHTOK_REQD; | |
1041 | ||
1042 | case -EOWNERDEAD: | |
1043 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Password expired, change required.")); | |
1044 | return PAM_NEW_AUTHTOK_REQD; | |
1045 | ||
1046 | /* Strictly speaking this is only about password expiration, and we might want to allow | |
1047 | * authentication via PKCS#11 or so, but let's ignore this fine distinction for now. */ | |
1048 | case -EKEYREJECTED: | |
1049 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Password is expired, but can't change, refusing login.")); | |
1050 | return PAM_AUTHTOK_EXPIRED; | |
1051 | ||
1052 | case -EKEYEXPIRED: | |
1053 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("Password will expire soon, please change.")); | |
1054 | break; | |
1055 | ||
1056 | case -ESTALE: | |
1057 | /* If the system clock is wrong, let's log but continue */ | |
1058 | pam_syslog(handle, LOG_WARNING, "Couldn't check if password change is required, last change is in the future, system clock likely wrong."); | |
1059 | break; | |
1060 | ||
1061 | case -EROFS: | |
1062 | /* All good, just means the password if we wanted to change we couldn't, but we don't need to */ | |
1063 | break; | |
1064 | ||
1065 | default: | |
1066 | if (r < 0) { | |
1067 | (void) pam_prompt_graceful(handle, PAM_ERROR_MSG, NULL, _("User record not valid, prohibiting access.")); | |
1068 | return PAM_AUTHTOK_EXPIRED; | |
1069 | } | |
1070 | } | |
1071 | ||
1072 | return PAM_SUCCESS; | |
1073 | } | |
1074 | ||
1075 | _public_ PAM_EXTERN int pam_sm_chauthtok( | |
1076 | pam_handle_t *handle, | |
1077 | int sm_flags, | |
1078 | int argc, | |
1079 | const char **argv) { | |
1080 | ||
1081 | _cleanup_(user_record_unrefp) UserRecord *ur = NULL, *old_secret = NULL, *new_secret = NULL; | |
1082 | const char *old_password = NULL, *new_password = NULL; | |
1083 | unsigned n_attempts = 0; | |
1084 | bool debug = false; | |
1085 | int r; | |
1086 | ||
1087 | pam_log_setup(); | |
1088 | ||
1089 | if (parse_argv(handle, | |
1090 | argc, argv, | |
1091 | NULL, | |
1092 | &debug) < 0) | |
1093 | return PAM_AUTH_ERR; | |
1094 | ||
1095 | pam_debug_syslog(handle, debug, "pam-systemd-homed account management"); | |
1096 | ||
1097 | r = acquire_user_record(handle, /* username= */ NULL, debug, &ur, /* bus_data= */ NULL); | |
1098 | if (r != PAM_SUCCESS) | |
1099 | return r; | |
1100 | ||
1101 | /* Start with cached credentials */ | |
1102 | r = pam_get_item_many( | |
1103 | handle, | |
1104 | PAM_OLDAUTHTOK, &old_password, | |
1105 | PAM_AUTHTOK, &new_password); | |
1106 | if (r != PAM_SUCCESS) | |
1107 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to get cached passwords: @PAMERR@"); | |
1108 | ||
1109 | if (isempty(new_password)) { | |
1110 | /* No, it's not cached, then let's ask for the password and its verification, and cache | |
1111 | * it. */ | |
1112 | ||
1113 | r = pam_get_authtok_noverify(handle, &new_password, "New password: "); | |
1114 | if (r != PAM_SUCCESS) | |
1115 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to get new password: @PAMERR@"); | |
1116 | ||
1117 | if (isempty(new_password)) { | |
1118 | pam_debug_syslog(handle, debug, "Password request aborted."); | |
1119 | return PAM_AUTHTOK_ERR; | |
1120 | } | |
1121 | ||
1122 | r = pam_get_authtok_verify(handle, &new_password, "new password: "); /* Lower case, since PAM prefixes 'Repeat' */ | |
1123 | if (r != PAM_SUCCESS) | |
1124 | return pam_syslog_pam_error(handle, LOG_ERR, r, "Failed to get password again: @PAMERR@"); | |
1125 | ||
1126 | // FIXME: pam_pwquality will ask for the password a third time. It really shouldn't do | |
1127 | // that, and instead assume the password was already verified once when it is found to be | |
1128 | // cached already. needs to be fixed in pam_pwquality | |
1129 | } | |
1130 | ||
1131 | /* Now everything is cached and checked, let's exit from the preliminary check */ | |
1132 | if (FLAGS_SET(sm_flags, PAM_PRELIM_CHECK)) | |
1133 | return PAM_SUCCESS; | |
1134 | ||
1135 | old_secret = user_record_new(); | |
1136 | if (!old_secret) | |
1137 | return pam_log_oom(handle); | |
1138 | ||
1139 | if (!isempty(old_password)) { | |
1140 | r = user_record_set_password(old_secret, STRV_MAKE(old_password), true); | |
1141 | if (r < 0) | |
1142 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store old password: %m"); | |
1143 | } | |
1144 | ||
1145 | new_secret = user_record_new(); | |
1146 | if (!new_secret) | |
1147 | return pam_log_oom(handle); | |
1148 | ||
1149 | r = user_record_set_password(new_secret, STRV_MAKE(new_password), true); | |
1150 | if (r < 0) | |
1151 | return pam_syslog_errno(handle, LOG_ERR, r, "Failed to store new password: %m"); | |
1152 | ||
1153 | _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; | |
1154 | r = pam_acquire_bus_connection(handle, "pam-systemd-home", debug, &bus, NULL); | |
1155 | if (r != PAM_SUCCESS) | |
1156 | return r; | |
1157 | ||
1158 | for (;;) { | |
1159 | _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; | |
1160 | _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; | |
1161 | ||
1162 | r = bus_message_new_method_call(bus, &m, bus_home_mgr, "ChangePasswordHome"); | |
1163 | if (r < 0) | |
1164 | return pam_bus_log_create_error(handle, r); | |
1165 | ||
1166 | r = sd_bus_message_append(m, "s", ur->user_name); | |
1167 | if (r < 0) | |
1168 | return pam_bus_log_create_error(handle, r); | |
1169 | ||
1170 | r = bus_message_append_secret(m, new_secret); | |
1171 | if (r < 0) | |
1172 | return pam_bus_log_create_error(handle, r); | |
1173 | ||
1174 | r = bus_message_append_secret(m, old_secret); | |
1175 | if (r < 0) | |
1176 | return pam_bus_log_create_error(handle, r); | |
1177 | ||
1178 | r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, NULL); | |
1179 | if (r < 0) { | |
1180 | r = handle_generic_user_record_error(handle, ur->user_name, old_secret, r, &error, debug); | |
1181 | if (r == PAM_CONV_ERR) | |
1182 | return pam_syslog_pam_error(handle, LOG_ERR, r, | |
1183 | "Failed to prompt for password/prompt."); | |
1184 | if (r != PAM_SUCCESS) | |
1185 | return r; | |
1186 | } else | |
1187 | return pam_syslog_pam_error(handle, LOG_NOTICE, PAM_SUCCESS, | |
1188 | "Successfully changed password for user %s.", ur->user_name); | |
1189 | ||
1190 | if (++n_attempts >= 5) | |
1191 | break; | |
1192 | ||
1193 | /* Try again */ | |
1194 | }; | |
1195 | ||
1196 | return pam_syslog_pam_error(handle, LOG_NOTICE, PAM_MAXTRIES, | |
1197 | "Failed to change password for user %s: @PAMERR@", ur->user_name); | |
1198 | } |