1 files changed, 493 insertions, 0 deletions

diff --git a/src/auth/db-passwd-file.c b/src/auth/db-passwd-file.c
new file mode 100644
index 0000000..e26c146
--- /dev/null
+++ b/src/auth/db-passwd-file.c
@@ -0,0 +1,493 @@
+/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
+
+#include "auth-common.h"
+
+#if defined (USERDB_PASSWD_FILE) || defined(PASSDB_PASSWD_FILE)
+
+#include "userdb.h"
+#include "db-passwd-file.h"
+
+#include "array.h"
+#include "buffer.h"
+#include "istream.h"
+#include "hash.h"
+#include "str.h"
+#include "eacces-error.h"
+#include "ioloop.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <time.h>
+#include <sys/stat.h>
+
+#define PARSE_TIME_STARTUP_WARN_SECS 60
+#define PARSE_TIME_RELOAD_WARN_SECS 10
+
+static struct db_passwd_file *passwd_files;
+
+static void ATTR_NULL(3)
+passwd_file_add(struct passwd_file *pw, const char *username,
+		const char *pass, const char *const *args)
+{
+	/* args = uid, gid, user info, home dir, shell, extra_fields */
+	struct passwd_user *pu;
+	const char *extra_fields = NULL;
+	char *user;
+	size_t len;
+
+	if (hash_table_lookup(pw->users, username) != NULL) {
+		e_error(pw->event, "User %s exists more than once", username);
+		return;
+	}
+
+	pu = p_new(pw->pool, struct passwd_user, 1);
+	user = p_strdup(pw->pool, username);
+
+	len = pass == NULL ? 0 : strlen(pass);
+	if (len > 4 && pass[0] != '{' && pass[0] != '$' &&
+	    pass[len-1] == ']' && pass[len-4] == '[') {
+		/* password[type] - we're being libpam-pwdfile compatible
+		   here. it uses 13 = DES and 34 = MD5. For backwards
+		   compatibility with ourself, we have also 56 = Digest-MD5. */
+		int num = (pass[len-3] - '0') * 10 + (pass[len-2] - '0');
+
+		pass = t_strndup(pass, len-4);
+		if (num == 34) {
+			pu->password = p_strconcat(pw->pool, "{PLAIN-MD5}",
+						   pass, NULL);
+		} else if (num == 56) {
+			pu->password = p_strconcat(pw->pool, "{DIGEST-MD5}",
+						   pass, NULL);
+			if (strlen(pu->password) != 32 + 12) {
+				e_error(pw->event, "User %s "
+					"has invalid password", username);
+				return;
+			}
+		} else {
+			pu->password = p_strconcat(pw->pool, "{CRYPT}",
+						   pass, NULL);
+		}
+	} else {
+		pu->password = p_strdup(pw->pool, pass);
+	}
+
+	pu->uid = (uid_t)-1;
+	pu->gid = (gid_t)-1;
+
+	if (*args == NULL)
+		;
+	else if (!pw->db->userdb || **args == '\0') {
+		args++;
+	} else {
+		pu->uid = userdb_parse_uid(NULL, *args);
+		if (pu->uid == 0 || pu->uid == (uid_t)-1) {
+			e_error(pw->event, "User %s has invalid UID '%s'",
+				username, *args);
+			return;
+		}
+		args++;
+	}
+
+	if (*args == NULL) {
+		if (pw->db->userdb_warn_missing) {
+			e_error(pw->event, "User %s is missing userdb info",
+				username);
+		}
+		/* don't allow userdb lookups */
+		pu->uid = 0;
+		pu->gid = 0;
+	} else if (!pw->db->userdb || **args == '\0')
+		args++;
+	else {
+		pu->gid = userdb_parse_gid(NULL, *args);
+		if (pu->gid == 0 || pu->gid == (gid_t)-1) {
+			e_error(pw->event, "User %s has invalid GID '%s'",
+				username, *args);
+			return;
+		}
+		args++;
+	}
+
+	/* user info */
+	if (*args != NULL)
+		args++;
+
+	/* home */
+	if (*args != NULL) {
+		if (pw->db->userdb)
+			pu->home = p_strdup_empty(pw->pool, *args);
+		args++;
+	}
+
+	/* shell */
+	if (*args != NULL)
+		args++;
+
+	if (*args != NULL && **args == '\0') {
+		/* old format, this field is empty and next field may
+		   contain MAIL */
+		args++;
+		if (*args != NULL && **args != '\0' && pw->db->userdb) {
+			extra_fields =
+                                t_strconcat("userdb_mail=",
+                                            t_strarray_join(args, ":"), NULL);
+		}
+	} else if (*args != NULL) {
+		/* new format, contains a space separated list of
+		   extra fields */
+                extra_fields = t_strarray_join(args, ":");
+        }
+
+        if (extra_fields != NULL) {
+                pu->extra_fields =
+                        p_strsplit_spaces(pw->pool, extra_fields, " ");
+        }
+
+	hash_table_insert(pw->users, user, pu);
+}
+
+static struct passwd_file *
+passwd_file_new(struct db_passwd_file *db, const char *expanded_path)
+{
+	struct passwd_file *pw;
+
+	pw = i_new(struct passwd_file, 1);
+	pw->db = db;
+	pw->path = i_strdup(expanded_path);
+	pw->fd = -1;
+	pw->event = event_create(db->event);
+	event_set_append_log_prefix(pw->event,
+		t_strdup_printf("passwd-file %s:", pw->path));
+
+	if (hash_table_is_created(db->files))
+		hash_table_insert(db->files, pw->path, pw);
+	return pw;
+}
+
+static int passwd_file_open(struct passwd_file *pw, bool startup,
+			    const char **error_r)
+{
+	const char *no_args = NULL;
+	struct istream *input;
+	const char *line;
+	struct stat st;
+	time_t start_time, end_time;
+	unsigned int time_secs;
+	int fd;
+
+	fd = open(pw->path, O_RDONLY);
+	if (fd == -1) {
+		if (errno == EACCES)
+			*error_r = eacces_error_get("open", pw->path);
+		else {
+			*error_r = t_strdup_printf("open(%s) failed: %m",
+						   pw->path);
+		}
+		return -1;
+	}
+
+	if (fstat(fd, &st) != 0) {
+		*error_r = t_strdup_printf("fstat(%s) failed: %m",
+					   pw->path);
+		i_close_fd(&fd);
+		return -1;
+	}
+
+	pw->fd = fd;
+	pw->stamp = st.st_mtime;
+	pw->size = st.st_size;
+
+	pw->pool = pool_alloconly_create(MEMPOOL_GROWING"passwd_file", 10240);
+	hash_table_create(&pw->users, pw->pool, 0, str_hash, strcmp);
+
+	start_time = time(NULL);
+	input = i_stream_create_fd(pw->fd, SIZE_MAX);
+	i_stream_set_return_partial_line(input, TRUE);
+	while ((line = i_stream_read_next_line(input)) != NULL) {
+		if (*line == '\0' || *line == ':' || *line == '#')
+			continue; /* no username or comment */
+
+		T_BEGIN {
+			const char *const *args = t_strsplit(line, ":");
+			if (args[1] != NULL) {
+				/* at least username+password */
+				passwd_file_add(pw, args[0], args[1], args+2);
+			} else {
+				/* only username */
+				passwd_file_add(pw, args[0], NULL, &no_args);
+			}
+		} T_END;
+	}
+	i_stream_destroy(&input);
+	end_time = time(NULL);
+	time_secs = end_time - start_time;
+
+	if ((time_secs > PARSE_TIME_STARTUP_WARN_SECS && startup) ||
+	    (time_secs > PARSE_TIME_RELOAD_WARN_SECS && !startup)) {
+		e_warning(pw->event, "Reading %u users took %u secs",
+			  hash_table_count(pw->users), time_secs);
+	} else {
+		e_debug(pw->event, "Read %u users in %u secs",
+			hash_table_count(pw->users), time_secs);
+	}
+	return 0;
+}
+
+static void passwd_file_close(struct passwd_file *pw)
+{
+	i_close_fd_path(&pw->fd, pw->path);
+
+	hash_table_destroy(&pw->users);
+	pool_unref(&pw->pool);
+}
+
+static void passwd_file_free(struct passwd_file *pw)
+{
+	if (hash_table_is_created(pw->db->files))
+		hash_table_remove(pw->db->files, pw->path);
+
+	passwd_file_close(pw);
+	event_unref(&pw->event);
+	i_free(pw->path);
+	i_free(pw);
+}
+
+static int passwd_file_sync(struct auth_request *request,
+			    struct passwd_file *pw)
+{
+	struct stat st;
+	const char *error;
+
+	if (pw->last_sync_time == ioloop_time)
+		return hash_table_is_created(pw->users) ? 1 : -1;
+	pw->last_sync_time = ioloop_time;
+
+	if (stat(pw->path, &st) < 0) {
+		/* with variables don't give hard errors, or errors about
+		   nonexistent files */
+		int ret = -1;
+
+		if (errno == EACCES) {
+			e_error(authdb_event(request),
+				"%s", eacces_error_get("stat", pw->path));
+		} else if (errno == ENOENT) {
+			auth_request_log_info(request, "passwd-file",
+					      "missing passwd file: %s", pw->path);
+			ret = 0;
+		} else {
+			e_error(authdb_event(request),
+				"stat(%s) failed: %m", pw->path);
+		}
+
+		if (pw->db->default_file != pw)
+			passwd_file_free(pw);
+		return ret;
+	}
+
+	if (st.st_mtime != pw->stamp || st.st_size != pw->size) {
+		passwd_file_close(pw);
+		if (passwd_file_open(pw, FALSE, &error) < 0) {
+			e_error(authdb_event(request),
+				"%s", error);
+			return -1;
+		}
+	}
+	return 1;
+}
+
+static struct db_passwd_file *db_passwd_file_find(const char *path)
+{
+	struct db_passwd_file *f;
+
+	for (f = passwd_files; f != NULL; f = f->next) {
+		if (strcmp(f->path, path) == 0)
+			return f;
+	}
+
+	return NULL;
+}
+
+static void db_passwd_file_set_userdb(struct db_passwd_file *db)
+{
+	db->userdb = TRUE;
+	/* warn about missing userdb fields only when there aren't any other
+	   userdbs. */
+	db->userdb_warn_missing =
+		array_is_created(&global_auth_settings->userdbs) &&
+		array_count(&global_auth_settings->userdbs) == 1;
+}
+
+struct db_passwd_file *
+db_passwd_file_init(const char *path, bool userdb, bool debug)
+{
+	struct db_passwd_file *db;
+	const char *p;
+	bool percents = FALSE;
+
+	db = db_passwd_file_find(path);
+	if (db != NULL) {
+		db->refcount++;
+		if (userdb)
+			db_passwd_file_set_userdb(db);
+		return db;
+	}
+
+	db = i_new(struct db_passwd_file, 1);
+	db->refcount = 1;
+	if (userdb)
+		db_passwd_file_set_userdb(db);
+	db->event = event_create(auth_event);
+	event_set_forced_debug(db->event, debug);
+
+	for (p = path; *p != '\0'; p++) {
+		if (*p == '%' && p[1] != '\0') {
+			if (var_get_key(++p) == '%')
+				percents = TRUE;
+			else
+				db->vars = TRUE;
+		}
+	}
+
+	if (percents && !db->vars) {
+		/* just extra escaped % chars. remove them. */
+		struct var_expand_table empty_table[1] = {
+			{ .key = '\0' },
+		};
+		string_t *dest;
+		const char *error;
+
+		dest = t_str_new(256);
+		if (var_expand(dest, path, empty_table, &error) <= 0)
+			i_unreached();
+		path = str_c(dest);
+	}
+
+	db->path = i_strdup(path);
+	if (db->vars) {
+		hash_table_create(&db->files, default_pool, 0,
+				  str_hash, strcmp);
+	} else {
+		db->default_file = passwd_file_new(db, path);
+	}
+
+	db->next = passwd_files;
+	passwd_files = db;
+	return db;
+}
+
+void db_passwd_file_parse(struct db_passwd_file *db)
+{
+	const char *error;
+
+	if (db->default_file != NULL && db->default_file->stamp == 0) {
+		/* no variables, open the file immediately */
+		if (passwd_file_open(db->default_file, TRUE, &error) < 0)
+			e_error(db->default_file->event, "%s", error);
+	}
+}
+
+void db_passwd_file_unref(struct db_passwd_file **_db)
+{
+        struct db_passwd_file *db = *_db;
+        struct db_passwd_file **p;
+	struct hash_iterate_context *iter;
+	char *path;
+	struct passwd_file *file;
+
+	*_db = NULL;
+	i_assert(db->refcount >= 0);
+	if (--db->refcount > 0)
+		return;
+
+	for (p = &passwd_files; *p != NULL; p = &(*p)->next) {
+		if (*p == db) {
+			*p = db->next;
+			break;
+		}
+	}
+
+	if (db->default_file != NULL)
+		passwd_file_free(db->default_file);
+	else {
+		iter = hash_table_iterate_init(db->files);
+		while (hash_table_iterate(iter, db->files, &path, &file))
+			passwd_file_free(file);
+		hash_table_iterate_deinit(&iter);
+		hash_table_destroy(&db->files);
+	}
+	event_unref(&db->event);
+	i_free(db->path);
+	i_free(db);
+}
+
+static const char *
+path_fix(const char *path,
+	 const struct auth_request *auth_request ATTR_UNUSED)
+{
+	const char *p;
+
+	p = strchr(path, '/');
+	if (p == NULL)
+		return path;
+
+	/* most likely this is an invalid request. just cut off the '/' and
+	   everything after it. */
+	return t_strdup_until(path, p);
+}
+
+int db_passwd_file_lookup(struct db_passwd_file *db,
+			  struct auth_request *request,
+			  const char *username_format,
+			  struct passwd_user **user_r)
+{
+	struct passwd_file *pw;
+	string_t *username, *dest;
+	const char *error;
+	int ret;
+
+	if (!db->vars)
+		pw = db->default_file;
+	else {
+		dest = t_str_new(256);
+		if (auth_request_var_expand(dest, db->path, request, path_fix,
+					    &error) <= 0) {
+			e_error(authdb_event(request),
+				"Failed to expand passwd-file path %s: %s",
+				db->path, error);
+			return -1;
+		}
+
+		pw = hash_table_lookup(db->files, str_c(dest));
+		if (pw == NULL) {
+			/* doesn't exist yet. create lookup for it. */
+			pw = passwd_file_new(db, str_c(dest));
+		}
+	}
+
+	if ((ret = passwd_file_sync(request, pw)) <= 0) {
+		/* pw may be freed now */
+		return ret;
+	}
+
+	username = t_str_new(256);
+	if (auth_request_var_expand(username, username_format, request,
+				    auth_request_str_escape, &error) <= 0) {
+		e_error(authdb_event(request),
+			"Failed to expand username_format=%s: %s",
+			username_format, error);
+		return -1;
+	}
+
+	e_debug(authdb_event(request),
+		"lookup: user=%s file=%s",
+		str_c(username), pw->path);
+
+	*user_r = hash_table_lookup(pw->users, str_c(username));
+	if (*user_r == NULL) {
+		auth_request_log_unknown_user(request, AUTH_SUBSYS_DB);
+		return 0;
+	}
+	return 1;
+}
+
+#endif