/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include "sd-bus.h" #include "bus-common-errors.h" #include "bus-locator.h" #include "bus-util.h" #include "errno-util.h" #include "fd-util.h" #include "home-util.h" #include "memory-util.h" #include "pam-util.h" #include "parse-util.h" #include "strv.h" #include "user-record-util.h" #include "user-record.h" #include "user-util.h" static int parse_argv( pam_handle_t *handle, int argc, const char **argv, bool *please_suspend, bool *debug) { int i; assert(argc >= 0); assert(argc == 0 || argv); for (i = 0; i < argc; i++) { const char *v; if ((v = startswith(argv[i], "suspend="))) { int k; k = parse_boolean(v); if (k < 0) pam_syslog(handle, LOG_WARNING, "Failed to parse suspend= argument, ignoring: %s", v); else if (please_suspend) *please_suspend = k; } else if (streq(argv[i], "debug")) { if (debug) *debug = true; } else if ((v = startswith(argv[i], "debug="))) { int k; k = parse_boolean(v); if (k < 0) pam_syslog(handle, LOG_WARNING, "Failed to parse debug= argument, ignoring: %s", v); else if (debug) *debug = k; } else pam_syslog(handle, LOG_WARNING, "Unknown parameter '%s', ignoring", argv[i]); } return 0; } static int parse_env( pam_handle_t *handle, bool *please_suspend) { const char *v; int r; /* Let's read the suspend setting from an env var in addition to the PAM command line. That makes it * easy to declare the features of a display manager in code rather than configuration, and this is * really a feature of code */ v = pam_getenv(handle, "SYSTEMD_HOME_SUSPEND"); if (!v) { /* Also check the process env block, so that people can control this via an env var from the * outside of our process. */ v = secure_getenv("SYSTEMD_HOME_SUSPEND"); if (!v) return 0; } r = parse_boolean(v); if (r < 0) pam_syslog(handle, LOG_WARNING, "Failed to parse $SYSTEMD_HOME_SUSPEND argument, ignoring: %s", v); else if (please_suspend) *please_suspend = r; return 0; } static int acquire_user_record( pam_handle_t *handle, const char *username, UserRecord **ret_record) { _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL; _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; _cleanup_(user_record_unrefp) UserRecord *ur = NULL; _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; _cleanup_free_ char *homed_field = NULL; const char *json = NULL; int r; assert(handle); if (!username) { r = pam_get_user(handle, &username, NULL); if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to get user name: %s", pam_strerror(handle, r)); return r; } if (isempty(username)) { pam_syslog(handle, LOG_ERR, "User name not set."); return PAM_SERVICE_ERR; } } /* Let's bypass all IPC complexity for the two user names we know for sure we don't manage, and for * user names we don't consider valid. */ if (STR_IN_SET(username, "root", NOBODY_USER_NAME) || !valid_user_group_name(username, 0)) return PAM_USER_UNKNOWN; /* We cache the user record in the PAM context. We use a field name that includes the username, since * clients might change the user name associated with a PAM context underneath us. Notably, 'sudo' * creates a single PAM context and first authenticates it with the user set to the originating user, * then updates the user for the destination user and issues the session stack with the same PAM * context. We thus must be prepared that the user record changes between calls and we keep any * caching separate. */ homed_field = strjoin("systemd-home-user-record-", username); if (!homed_field) return pam_log_oom(handle); /* Let's use the cache, so that we can share it between the session and the authentication hooks */ r = pam_get_data(handle, homed_field, (const void**) &json); if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) { pam_syslog(handle, LOG_ERR, "Failed to get PAM user record data: %s", pam_strerror(handle, r)); return r; } if (r == PAM_SUCCESS && json) { /* We determined earlier that this is not a homed user? Then exit early. (We use -1 as * negative cache indicator) */ if (json == POINTER_MAX) return PAM_USER_UNKNOWN; } else { _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; _cleanup_free_ char *generic_field = NULL, *json_copy = NULL; r = pam_acquire_bus_connection(handle, &bus); if (r != PAM_SUCCESS) return r; r = bus_call_method(bus, bus_home_mgr, "GetUserRecordByName", &error, &reply, "s", username); if (r < 0) { if (bus_error_is_unknown_service(&error)) { pam_syslog(handle, LOG_DEBUG, "systemd-homed is not available: %s", bus_error_message(&error, r)); goto user_unknown; } if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_HOME)) { pam_syslog(handle, LOG_DEBUG, "Not a user managed by systemd-homed: %s", bus_error_message(&error, r)); goto user_unknown; } pam_syslog(handle, LOG_ERR, "Failed to query user record: %s", bus_error_message(&error, r)); return PAM_SERVICE_ERR; } r = sd_bus_message_read(reply, "sbo", &json, NULL, NULL); if (r < 0) return pam_bus_log_parse_error(handle, r); /* First copy: for the homed-specific data field, i.e. where we know the user record is from * homed */ json_copy = strdup(json); if (!json_copy) return pam_log_oom(handle); r = pam_set_data(handle, homed_field, json_copy, pam_cleanup_free); if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to set PAM user record data '%s': %s", homed_field, pam_strerror(handle, r)); return r; } /* Take a second copy: for the generic data field, the one which we share with * pam_systemd. While we insist on only reusing homed records, pam_systemd is fine with homed * and non-homed user records. */ json_copy = strdup(json); if (!json_copy) return pam_log_oom(handle); generic_field = strjoin("systemd-user-record-", username); if (!generic_field) return pam_log_oom(handle); r = pam_set_data(handle, generic_field, json_copy, pam_cleanup_free); if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to set PAM user record data '%s': %s", homed_field, pam_strerror(handle, r)); return r; } TAKE_PTR(json_copy); } r = json_parse(json, JSON_PARSE_SENSITIVE, &v, NULL, NULL); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to parse JSON user record: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } ur = user_record_new(); if (!ur) return pam_log_oom(handle); r = user_record_load(ur, v, USER_RECORD_LOAD_REFUSE_SECRET); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to load user record: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } /* Safety check if cached record actually matches what we are looking for */ if (!streq_ptr(username, ur->user_name)) { pam_syslog(handle, LOG_ERR, "Acquired user record does not match user name."); return PAM_SERVICE_ERR; } if (ret_record) *ret_record = TAKE_PTR(ur); return PAM_SUCCESS; user_unknown: /* Cache this, so that we don't check again */ r = pam_set_data(handle, homed_field, POINTER_MAX, NULL); if (r != PAM_SUCCESS) pam_syslog(handle, LOG_ERR, "Failed to set PAM user record data '%s' to invalid, ignoring: %s", homed_field, pam_strerror(handle, r)); return PAM_USER_UNKNOWN; } static int release_user_record(pam_handle_t *handle, const char *username) { _cleanup_free_ char *homed_field = NULL, *generic_field = NULL; int r, k; assert(handle); assert(username); homed_field = strjoin("systemd-home-user-record-", username); if (!homed_field) return pam_log_oom(handle); r = pam_set_data(handle, homed_field, NULL, NULL); if (r != PAM_SUCCESS) pam_syslog(handle, LOG_ERR, "Failed to release PAM user record data '%s': %s", homed_field, pam_strerror(handle, r)); generic_field = strjoin("systemd-user-record-", username); if (!generic_field) return pam_log_oom(handle); k = pam_set_data(handle, generic_field, NULL, NULL); if (k != PAM_SUCCESS) pam_syslog(handle, LOG_ERR, "Failed to release PAM user record data '%s': %s", generic_field, pam_strerror(handle, k)); return IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA) ? k : r; } static void cleanup_home_fd(pam_handle_t *handle, void *data, int error_status) { safe_close(PTR_TO_FD(data)); } static int handle_generic_user_record_error( pam_handle_t *handle, const char *user_name, UserRecord *secret, int ret, const sd_bus_error *error) { assert(user_name); assert(secret); assert(error); int r; /* Logs about all errors, except for PAM_CONV_ERR, i.e. when requesting more info failed. */ if (sd_bus_error_has_name(error, BUS_ERROR_HOME_ABSENT)) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Home of user %s is currently absent, please plug in the necessary storage device or backing file system.", user_name); pam_syslog(handle, LOG_ERR, "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); return PAM_PERM_DENIED; } else if (sd_bus_error_has_name(error, BUS_ERROR_AUTHENTICATION_LIMIT_HIT)) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Too frequent unsuccessful login attempts for user %s, try again later.", user_name); pam_syslog(handle, LOG_ERR, "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); return PAM_MAXTRIES; } else if (sd_bus_error_has_name(error, BUS_ERROR_BAD_PASSWORD)) { _cleanup_(erase_and_freep) char *newp = NULL; /* This didn't work? Ask for an (additional?) password */ if (strv_isempty(secret->password)) r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Password: "); else { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password incorrect or not sufficient for authentication of user %s.", user_name); r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Sorry, try again: "); } if (r != PAM_SUCCESS) return PAM_CONV_ERR; /* no logging here */ if (isempty(newp)) { pam_syslog(handle, LOG_DEBUG, "Password request aborted."); return PAM_AUTHTOK_ERR; } r = user_record_set_password(secret, STRV_MAKE(newp), true); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store password: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } else if (sd_bus_error_has_name(error, BUS_ERROR_BAD_PASSWORD_AND_NO_TOKEN)) { _cleanup_(erase_and_freep) char *newp = NULL; if (strv_isempty(secret->password)) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Security token of user %s not inserted.", user_name); r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Try again with password: "); } else { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password incorrect or not sufficient, and configured security token of user %s not inserted.", user_name); r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Try again with password: "); } if (r != PAM_SUCCESS) return PAM_CONV_ERR; /* no logging here */ if (isempty(newp)) { pam_syslog(handle, LOG_DEBUG, "Password request aborted."); return PAM_AUTHTOK_ERR; } r = user_record_set_password(secret, STRV_MAKE(newp), true); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store password: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_PIN_NEEDED)) { _cleanup_(erase_and_freep) char *newp = NULL; r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Security token PIN: "); if (r != PAM_SUCCESS) return PAM_CONV_ERR; /* no logging here */ if (isempty(newp)) { pam_syslog(handle, LOG_DEBUG, "PIN request aborted."); return PAM_AUTHTOK_ERR; } r = user_record_set_token_pin(secret, STRV_MAKE(newp), false); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store PIN: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_PROTECTED_AUTHENTICATION_PATH_NEEDED)) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Please authenticate physically on security token of user %s.", user_name); r = user_record_set_pkcs11_protected_authentication_path_permitted(secret, true); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to set PKCS#11 protected authentication path permitted flag: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_USER_PRESENCE_NEEDED)) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Please verify presence on security token of user %s.", user_name); r = user_record_set_fido2_user_presence_permitted(secret, true); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to set FIDO2 user presence permitted flag: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_PIN_LOCKED)) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Security token PIN is locked, please unlock it first. (Hint: Removal and re-insertion might suffice.)"); return PAM_SERVICE_ERR; } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN)) { _cleanup_(erase_and_freep) char *newp = NULL; (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Security token PIN incorrect for user %s.", user_name); r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Sorry, retry security token PIN: "); if (r != PAM_SUCCESS) return PAM_CONV_ERR; /* no logging here */ if (isempty(newp)) { pam_syslog(handle, LOG_DEBUG, "PIN request aborted."); return PAM_AUTHTOK_ERR; } r = user_record_set_token_pin(secret, STRV_MAKE(newp), false); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store PIN: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN_FEW_TRIES_LEFT)) { _cleanup_(erase_and_freep) char *newp = NULL; (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Security token PIN of user %s incorrect (only a few tries left!)", user_name); r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Sorry, retry security token PIN: "); if (r != PAM_SUCCESS) return PAM_CONV_ERR; /* no logging here */ if (isempty(newp)) { pam_syslog(handle, LOG_DEBUG, "PIN request aborted."); return PAM_AUTHTOK_ERR; } r = user_record_set_token_pin(secret, STRV_MAKE(newp), false); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store PIN: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } else if (sd_bus_error_has_name(error, BUS_ERROR_TOKEN_BAD_PIN_ONE_TRY_LEFT)) { _cleanup_(erase_and_freep) char *newp = NULL; (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Security token PIN of user %s incorrect (only one try left!)", user_name); r = pam_prompt(handle, PAM_PROMPT_ECHO_OFF, &newp, "Sorry, retry security token PIN: "); if (r != PAM_SUCCESS) return PAM_CONV_ERR; /* no logging here */ if (isempty(newp)) { pam_syslog(handle, LOG_DEBUG, "PIN request aborted."); return PAM_AUTHTOK_ERR; } r = user_record_set_token_pin(secret, STRV_MAKE(newp), false); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store PIN: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } else { pam_syslog(handle, LOG_ERR, "Failed to acquire home for user %s: %s", user_name, bus_error_message(error, ret)); return PAM_SERVICE_ERR; } return PAM_SUCCESS; } static int acquire_home( pam_handle_t *handle, bool please_authenticate, bool please_suspend, bool debug) { _cleanup_(user_record_unrefp) UserRecord *ur = NULL, *secret = NULL; bool do_auth = please_authenticate, home_not_active = false, home_locked = false; _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; _cleanup_close_ int acquired_fd = -1; _cleanup_free_ char *fd_field = NULL; const void *home_fd_ptr = NULL; const char *username = NULL; unsigned n_attempts = 0; int r; assert(handle); /* This acquires a reference to a home directory in one of two ways: if please_authenticate is true, * then we'll call AcquireHome() after asking the user for a password. Otherwise it tries to call * RefHome() and if that fails queries the user for a password and uses AcquireHome(). * * The idea is that the PAM authentication hook sets please_authenticate and thus always * authenticates, while the other PAM hooks unset it so that they can a ref of their own without * authentication if possible, but with authentication if necessary. */ r = pam_get_user(handle, &username, NULL); if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to get user name: %s", pam_strerror(handle, r)); return r; } if (isempty(username)) { pam_syslog(handle, LOG_ERR, "User name not set."); return PAM_SERVICE_ERR; } /* If we already have acquired the fd, let's shortcut this */ fd_field = strjoin("systemd-home-fd-", username); if (!fd_field) return pam_log_oom(handle); r = pam_get_data(handle, fd_field, &home_fd_ptr); if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) { pam_syslog(handle, LOG_ERR, "Failed to retrieve PAM home reference fd: %s", pam_strerror(handle, r)); return r; } if (r == PAM_SUCCESS && PTR_TO_FD(home_fd_ptr) >= 0) return PAM_SUCCESS; r = pam_acquire_bus_connection(handle, &bus); if (r != PAM_SUCCESS) return r; r = acquire_user_record(handle, username, &ur); if (r != PAM_SUCCESS) return r; /* Implement our own retry loop here instead of relying on the PAM client's one. That's because it * might happen that the record we stored on the host does not match the encryption password of * the LUKS image in case the image was used in a different system where the password was * changed. In that case it will happen that the LUKS password and the host password are * different, and we handle that by collecting and passing multiple passwords in that case. Hence we * treat bad passwords as a request to collect one more password and pass the new all all previously * used passwords again. */ for (;;) { _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL, *reply = NULL; _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; if (do_auth && !secret) { const char *cached_password = NULL; secret = user_record_new(); if (!secret) return pam_log_oom(handle); /* If there's already a cached password, use it. But if not let's authenticate * without anything, maybe some other authentication mechanism systemd-homed * implements (such as PKCS#11) allows us to authenticate without anything else. */ r = pam_get_item(handle, PAM_AUTHTOK, (const void**) &cached_password); if (!IN_SET(r, PAM_BAD_ITEM, PAM_SUCCESS)) { pam_syslog(handle, LOG_ERR, "Failed to get cached password: %s", pam_strerror(handle, r)); return r; } if (!isempty(cached_password)) { r = user_record_set_password(secret, STRV_MAKE(cached_password), true); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store password: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } } r = bus_message_new_method_call(bus, &m, bus_home_mgr, do_auth ? "AcquireHome" : "RefHome"); if (r < 0) return pam_bus_log_create_error(handle, r); r = sd_bus_message_append(m, "s", ur->user_name); if (r < 0) return pam_bus_log_create_error(handle, r); if (do_auth) { r = bus_message_append_secret(m, secret); if (r < 0) return pam_bus_log_create_error(handle, r); } r = sd_bus_message_append(m, "b", please_suspend); if (r < 0) return pam_bus_log_create_error(handle, r); r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, &reply); if (r < 0) { if (sd_bus_error_has_name(&error, BUS_ERROR_HOME_NOT_ACTIVE)) /* Only on RefHome(): We can't access the home directory currently, unless * it's unlocked with a password. Hence, let's try this again, this time with * authentication. */ home_not_active = true; else if (sd_bus_error_has_name(&error, BUS_ERROR_HOME_LOCKED)) home_locked = true; /* Similar */ else { r = handle_generic_user_record_error(handle, ur->user_name, secret, r, &error); if (r == PAM_CONV_ERR) { /* Password/PIN prompts will fail in certain environments, for example when * we are called from OpenSSH's account or session hooks, or in systemd's * per-service PAM logic. In that case, print a friendly message and accept * failure. */ if (home_not_active) (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Home of user %s is currently not active, please log in locally first.", ur->user_name); if (home_locked) (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Home of user %s is currently locked, please unlock locally first.", ur->user_name); pam_syslog(handle, please_authenticate ? LOG_ERR : LOG_DEBUG, "Failed to prompt for password/prompt."); return home_not_active || home_locked ? PAM_PERM_DENIED : PAM_CONV_ERR; } if (r != PAM_SUCCESS) return r; } } else { int fd; r = sd_bus_message_read(reply, "h", &fd); if (r < 0) return pam_bus_log_parse_error(handle, r); acquired_fd = fcntl(fd, F_DUPFD_CLOEXEC, 3); if (acquired_fd < 0) { pam_syslog(handle, LOG_ERR, "Failed to duplicate acquired fd: %s", bus_error_message(&error, r)); return PAM_SERVICE_ERR; } break; } if (++n_attempts >= 5) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Too many unsuccessful login attempts for user %s, refusing.", ur->user_name); pam_syslog(handle, LOG_ERR, "Failed to acquire home for user %s: %s", ur->user_name, bus_error_message(&error, r)); return PAM_MAXTRIES; } /* Try again, this time with authentication if we didn't do that before. */ do_auth = true; } /* Later PAM modules may need the auth token, but only during pam_authenticate. */ if (please_authenticate && !strv_isempty(secret->password)) { r = pam_set_item(handle, PAM_AUTHTOK, *secret->password); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to set PAM auth token: %s", pam_strerror(handle, r)); return r; } } r = pam_set_data(handle, fd_field, FD_TO_PTR(acquired_fd), cleanup_home_fd); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to set PAM bus data: %s", pam_strerror(handle, r)); return r; } TAKE_FD(acquired_fd); if (do_auth) { /* We likely just activated the home directory, let's flush out the user record, since a * newer embedded user record might have been acquired from the activation. */ r = release_user_record(handle, ur->user_name); if (!IN_SET(r, PAM_SUCCESS, PAM_NO_MODULE_DATA)) return r; } pam_syslog(handle, LOG_NOTICE, "Home for user %s successfully acquired.", ur->user_name); return PAM_SUCCESS; } static int release_home_fd(pam_handle_t *handle, const char *username) { _cleanup_free_ char *fd_field = NULL; const void *home_fd_ptr = NULL; int r; assert(handle); assert(username); fd_field = strjoin("systemd-home-fd-", username); if (!fd_field) return pam_log_oom(handle); r = pam_get_data(handle, fd_field, &home_fd_ptr); if (r == PAM_NO_MODULE_DATA || (r == PAM_SUCCESS && PTR_TO_FD(home_fd_ptr) < 0)) return PAM_NO_MODULE_DATA; if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to retrieve PAM home reference fd: %s", pam_strerror(handle, r)); return r; } r = pam_set_data(handle, fd_field, NULL, NULL); if (r != PAM_SUCCESS) pam_syslog(handle, LOG_ERR, "Failed to release PAM home reference fd: %s", pam_strerror(handle, r)); return r; } _public_ PAM_EXTERN int pam_sm_authenticate( pam_handle_t *handle, int flags, int argc, const char **argv) { bool debug = false, suspend_please = false; if (parse_env(handle, &suspend_please) < 0) return PAM_AUTH_ERR; if (parse_argv(handle, argc, argv, &suspend_please, &debug) < 0) return PAM_AUTH_ERR; if (debug) pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed authenticating"); return acquire_home(handle, /* please_authenticate= */ true, suspend_please, debug); } _public_ PAM_EXTERN int pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv) { return PAM_SUCCESS; } _public_ PAM_EXTERN int pam_sm_open_session( pam_handle_t *handle, int flags, int argc, const char **argv) { bool debug = false, suspend_please = false; int r; if (parse_env(handle, &suspend_please) < 0) return PAM_SESSION_ERR; if (parse_argv(handle, argc, argv, &suspend_please, &debug) < 0) return PAM_SESSION_ERR; if (debug) pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed session start"); r = acquire_home(handle, /* please_authenticate = */ false, suspend_please, debug); if (r == PAM_USER_UNKNOWN) /* Not managed by us? Don't complain. */ return PAM_SUCCESS; if (r != PAM_SUCCESS) return r; r = pam_putenv(handle, "SYSTEMD_HOME=1"); if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to set PAM environment variable $SYSTEMD_HOME: %s", pam_strerror(handle, r)); return r; } r = pam_putenv(handle, suspend_please ? "SYSTEMD_HOME_SUSPEND=1" : "SYSTEMD_HOME_SUSPEND=0"); if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to set PAM environment variable $SYSTEMD_HOME_SUSPEND: %s", pam_strerror(handle, r)); return r; } /* Let's release the D-Bus connection, after all the session might live quite a long time, and we are * not going to process the bus connection in that time, so let's better close before the daemon * kicks us off because we are not processing anything. */ (void) pam_release_bus_connection(handle); return PAM_SUCCESS; } _public_ PAM_EXTERN int pam_sm_close_session( pam_handle_t *handle, int flags, int argc, const char **argv) { _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; const char *username = NULL; bool debug = false; int r; if (parse_argv(handle, argc, argv, NULL, &debug) < 0) return PAM_SESSION_ERR; if (debug) pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed session end"); r = pam_get_user(handle, &username, NULL); if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to get user name: %s", pam_strerror(handle, r)); return r; } if (isempty(username)) { pam_syslog(handle, LOG_ERR, "User name not set."); return PAM_SERVICE_ERR; } /* Let's explicitly drop the reference to the homed session, so that the subsequent ReleaseHome() * call will be able to do its thing. */ r = release_home_fd(handle, username); if (r == PAM_NO_MODULE_DATA) /* Nothing to do, we never acquired an fd */ return PAM_SUCCESS; if (r != PAM_SUCCESS) return r; r = pam_acquire_bus_connection(handle, &bus); if (r != PAM_SUCCESS) return r; r = bus_message_new_method_call(bus, &m, bus_home_mgr, "ReleaseHome"); if (r < 0) return pam_bus_log_create_error(handle, r); r = sd_bus_message_append(m, "s", username); if (r < 0) return pam_bus_log_create_error(handle, r); r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, NULL); if (r < 0) { if (sd_bus_error_has_name(&error, BUS_ERROR_HOME_BUSY)) pam_syslog(handle, LOG_NOTICE, "Not deactivating home directory of %s, as it is still used.", username); else { pam_syslog(handle, LOG_ERR, "Failed to release user home: %s", bus_error_message(&error, r)); return PAM_SESSION_ERR; } } return PAM_SUCCESS; } _public_ PAM_EXTERN int pam_sm_acct_mgmt( pam_handle_t *handle, int flags, int argc, const char **argv) { _cleanup_(user_record_unrefp) UserRecord *ur = NULL; bool debug = false, please_suspend = false; usec_t t; int r; if (parse_env(handle, &please_suspend) < 0) return PAM_AUTH_ERR; if (parse_argv(handle, argc, argv, &please_suspend, &debug) < 0) return PAM_AUTH_ERR; if (debug) pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed account management"); r = acquire_home(handle, /* please_authenticate = */ false, please_suspend, debug); if (r != PAM_SUCCESS) return r; r = acquire_user_record(handle, NULL, &ur); if (r != PAM_SUCCESS) return r; r = user_record_test_blocked(ur); switch (r) { case -ESTALE: pam_syslog(handle, LOG_WARNING, "User record for '%s' is newer than current system time, assuming incorrect system clock, allowing access.", ur->user_name); break; case -ENOLCK: (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record is blocked, prohibiting access."); return PAM_ACCT_EXPIRED; case -EL2HLT: (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record is not valid yet, prohibiting access."); return PAM_ACCT_EXPIRED; case -EL3HLT: (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record is not valid anymore, prohibiting access."); return PAM_ACCT_EXPIRED; default: if (r < 0) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record not valid, prohibiting access."); return PAM_ACCT_EXPIRED; } break; } t = user_record_ratelimit_next_try(ur); if (t != USEC_INFINITY) { usec_t n = now(CLOCK_REALTIME); if (t > n) { char buf[FORMAT_TIMESPAN_MAX]; (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Too many logins, try again in %s.", format_timespan(buf, sizeof(buf), t - n, USEC_PER_SEC)); return PAM_MAXTRIES; } } r = user_record_test_password_change_required(ur); switch (r) { case -EKEYREVOKED: (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password change required."); return PAM_NEW_AUTHTOK_REQD; case -EOWNERDEAD: (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password expired, change required."); return PAM_NEW_AUTHTOK_REQD; case -EKEYREJECTED: /* Strictly speaking this is only about password expiration, and we might want to allow * authentication via PKCS#11 or so, but let's ignore this fine distinction for now. */ (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password is expired, but can't change, refusing login."); return PAM_AUTHTOK_EXPIRED; case -EKEYEXPIRED: (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "Password will expire soon, please change."); break; case -ESTALE: /* If the system clock is wrong, let's log but continue */ pam_syslog(handle, LOG_WARNING, "Couldn't check if password change is required, last change is in the future, system clock likely wrong."); break; case -EROFS: /* All good, just means the password if we wanted to change we couldn't, but we don't need to */ break; default: if (r < 0) { (void) pam_prompt(handle, PAM_ERROR_MSG, NULL, "User record not valid, prohibiting access."); return PAM_AUTHTOK_EXPIRED; } break; } return PAM_SUCCESS; } _public_ PAM_EXTERN int pam_sm_chauthtok( pam_handle_t *handle, int flags, int argc, const char **argv) { _cleanup_(user_record_unrefp) UserRecord *ur = NULL, *old_secret = NULL, *new_secret = NULL; const char *old_password = NULL, *new_password = NULL; _cleanup_(sd_bus_unrefp) sd_bus *bus = NULL; unsigned n_attempts = 0; bool debug = false; int r; if (parse_argv(handle, argc, argv, NULL, &debug) < 0) return PAM_AUTH_ERR; if (debug) pam_syslog(handle, LOG_DEBUG, "pam-systemd-homed account management"); r = pam_acquire_bus_connection(handle, &bus); if (r != PAM_SUCCESS) return r; r = acquire_user_record(handle, NULL, &ur); if (r != PAM_SUCCESS) return r; /* Start with cached credentials */ r = pam_get_item(handle, PAM_OLDAUTHTOK, (const void**) &old_password); if (!IN_SET(r, PAM_BAD_ITEM, PAM_SUCCESS)) { pam_syslog(handle, LOG_ERR, "Failed to get old password: %s", pam_strerror(handle, r)); return r; } r = pam_get_item(handle, PAM_AUTHTOK, (const void**) &new_password); if (!IN_SET(r, PAM_BAD_ITEM, PAM_SUCCESS)) { pam_syslog(handle, LOG_ERR, "Failed to get cached password: %s", pam_strerror(handle, r)); return r; } if (isempty(new_password)) { /* No, it's not cached, then let's ask for the password and its verification, and cache * it. */ r = pam_get_authtok_noverify(handle, &new_password, "New password: "); if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to get new password: %s", pam_strerror(handle, r)); return r; } if (isempty(new_password)) { pam_syslog(handle, LOG_DEBUG, "Password request aborted."); return PAM_AUTHTOK_ERR; } r = pam_get_authtok_verify(handle, &new_password, "new password: "); /* Lower case, since PAM prefixes 'Repeat' */ if (r != PAM_SUCCESS) { pam_syslog(handle, LOG_ERR, "Failed to get password again: %s", pam_strerror(handle, r)); return r; } // FIXME: pam_pwquality will ask for the password a third time. It really shouldn't do // that, and instead assume the password was already verified once when it is found to be // cached already. needs to be fixed in pam_pwquality } /* Now everything is cached and checked, let's exit from the preliminary check */ if (FLAGS_SET(flags, PAM_PRELIM_CHECK)) return PAM_SUCCESS; old_secret = user_record_new(); if (!old_secret) return pam_log_oom(handle); if (!isempty(old_password)) { r = user_record_set_password(old_secret, STRV_MAKE(old_password), true); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store old password: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } } new_secret = user_record_new(); if (!new_secret) return pam_log_oom(handle); r = user_record_set_password(new_secret, STRV_MAKE(new_password), true); if (r < 0) { pam_syslog(handle, LOG_ERR, "Failed to store new password: %s", strerror_safe(r)); return PAM_SERVICE_ERR; } for (;;) { _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL; r = bus_message_new_method_call(bus, &m, bus_home_mgr, "ChangePasswordHome"); if (r < 0) return pam_bus_log_create_error(handle, r); r = sd_bus_message_append(m, "s", ur->user_name); if (r < 0) return pam_bus_log_create_error(handle, r); r = bus_message_append_secret(m, new_secret); if (r < 0) return pam_bus_log_create_error(handle, r); r = bus_message_append_secret(m, old_secret); if (r < 0) return pam_bus_log_create_error(handle, r); r = sd_bus_call(bus, m, HOME_SLOW_BUS_CALL_TIMEOUT_USEC, &error, NULL); if (r < 0) { r = handle_generic_user_record_error(handle, ur->user_name, old_secret, r, &error); if (r == PAM_CONV_ERR) { pam_syslog(handle, LOG_ERR, "Failed to prompt for password/prompt."); return PAM_CONV_ERR; } if (r != PAM_SUCCESS) return r; } else { pam_syslog(handle, LOG_NOTICE, "Successfully changed password for user %s.", ur->user_name); return PAM_SUCCESS; } if (++n_attempts >= 5) break; /* Try again */ }; pam_syslog(handle, LOG_NOTICE, "Failed to change password for user %s: %m", ur->user_name); return PAM_MAXTRIES; }