diff options
Diffstat (limited to 'system_cmds/passwd.tproj/file_passwd.c')
| -rw-r--r-- | system_cmds/passwd.tproj/file_passwd.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/system_cmds/passwd.tproj/file_passwd.c b/system_cmds/passwd.tproj/file_passwd.c new file mode 100644 index 0000000..62d27f3 --- /dev/null +++ b/system_cmds/passwd.tproj/file_passwd.c @@ -0,0 +1,237 @@ +/* + * Copyright (c) 1999-2016 Apple Inc. All rights reserved. + * + * @APPLE_LICENSE_HEADER_START@ + * + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this + * file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, + * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. + * + * @APPLE_LICENSE_HEADER_END@ + */ +#include <ctype.h> +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <pwd.h> +#include <signal.h> +#include <stdbool.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <sysexits.h> +#include <unistd.h> +#include <sys/time.h> +#include <sys/stat.h> +#include "passwd.h" + +#define _PASSWD_FILE "/etc/master.passwd" +#define _COMPAT_FILE "/etc/passwd" +#define _PASSWD_FIELDS 10 +#define BUFSIZE 8192 + +void getpasswd(char *, int, int, int, int, char *, char **, char**, char **); + +static struct passwd * +parse_user(char *line, size_t len) +{ + static struct passwd pw; + int i,j; + char *tokens[_PASSWD_FIELDS]; + char *token = NULL; + bool comment = true; + + free(pw.pw_name); + free(pw.pw_passwd); + free(pw.pw_class); + free(pw.pw_gecos); + free(pw.pw_dir); + free(pw.pw_shell); + memset(&pw, 0, sizeof(pw)); + + if (line == NULL) return NULL; + + memset(&tokens, 0, sizeof(char *) * _PASSWD_FIELDS); + + for (i = 0, j = 0; i < len && j < _PASSWD_FIELDS; ++i) { + int c = line[i]; + if (!isspace(c) && c != '#') { + comment = false; + } + if (!comment && token == NULL) { + // start a new token + token = &line[i]; + } else if (token && (c == ':' || c == '\n')) { + // end the current token + // special case for empty token + while (token[0] == ':' && token < &line[i]) { + tokens[j++] = strdup(""); + ++token; + } + tokens[j++] = strndup(token, &line[i] - token); + token = NULL; + } + } + + if (comment || j != _PASSWD_FIELDS) return NULL; + + j = 0; + pw.pw_name = tokens[j++]; + pw.pw_passwd = tokens[j++]; + pw.pw_uid = atoi(tokens[j]); + free(tokens[j++]); + pw.pw_gid = atoi(tokens[j]); + free(tokens[j++]); + pw.pw_class = tokens[j++]; + pw.pw_change = atoi(tokens[j]); + free(tokens[j++]); + pw.pw_expire = atoi(tokens[j]); + free(tokens[j++]); + pw.pw_gecos = tokens[j++]; + pw.pw_dir = tokens[j++]; + pw.pw_shell = tokens[j++]; + + return &pw; +} + +static struct passwd * +find_user(FILE *fp, char *uname) +{ + size_t len; + char *line; + + rewind(fp); + + while ((line = fgetln(fp, &len)) != NULL) { + struct passwd *pw = parse_user(line, len); + if (pw && strcmp(uname, pw->pw_name) == 0) { + return pw; + } + } + return NULL; +} + +static void +rewrite_file(char *path, FILE *fp, struct passwd *newpw) +{ + int fd; + char *line; + size_t len; + FILE *tfp = NULL; + char *tempname = NULL; // temporary master.passwd file + + asprintf(&tempname, "%s.XXXXXX", path); + + fd = mkstemp(tempname); + if (fd == -1) { + err(EXIT_FAILURE, "%s", tempname); + } + tfp = fdopen(fd, "w+"); + if (tfp == NULL || fchmod(fd, S_IRUSR | S_IWUSR) != 0) { + int save = errno; + unlink(tempname); + errno = save; + err(EXIT_FAILURE, "%s", tempname); + } + + while ((line = fgetln(fp, &len)) != NULL) { + struct passwd *pw = parse_user(line, len); + + // if this is not the entry we're looking for or if parsing + // failed (likely a comment) then print the entry as is. + if (pw == NULL || strcmp(newpw->pw_name, pw->pw_name) != 0) { + fwrite(line, sizeof(char), len, tfp); + } else { + fprintf(tfp, "%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", + newpw->pw_name, + newpw->pw_passwd, + newpw->pw_uid, + newpw->pw_gid, + newpw->pw_class, + newpw->pw_change, + newpw->pw_expire, + newpw->pw_gecos, + newpw->pw_dir, + newpw->pw_shell); + } + } + + // Move the temporary file into place. + if (fclose(tfp) != 0 || rename(tempname, path) != 0) { + int save = errno; + unlink(tempname); + errno = save; + err(EXIT_FAILURE, "%s", tempname); + } + + free(tempname); +} + +int +file_passwd(char *uname, char *locn) +{ + char *ne, *oc, *nc; + int fd; + FILE *fp; + uid_t uid; + char *fname; + struct passwd *pw; + struct passwd newpw; + + fname = _PASSWD_FILE; + if (locn != NULL) fname = locn; + + fd = open(fname, O_RDONLY | O_EXLOCK); + if (fd == -1) { + err(EXIT_FAILURE, "%s", fname); + } + + fp = fdopen(fd, "r"); + if (fp == NULL) { + err(EXIT_FAILURE, "%s", fname); + } + + pw = find_user(fp, uname); + if (pw == NULL) { + errx(EXIT_FAILURE, "user %s not found in %s", uname, fname); + } + + uid = getuid(); + if (uid != 0 && uid != pw->pw_uid) { + errno = EACCES; + err(EXIT_FAILURE, "%s", uname); + } + + // Get the password + getpasswd(uname, (uid == 0), 5, 0, 0, pw->pw_passwd, &ne, &oc, &nc); + + newpw.pw_name = strdup(pw->pw_name); + newpw.pw_passwd = strdup(ne); + newpw.pw_uid = pw->pw_uid; + newpw.pw_gid = pw->pw_gid; + newpw.pw_class = strdup(pw->pw_class); + newpw.pw_change = pw->pw_change; + newpw.pw_expire = pw->pw_expire; + newpw.pw_gecos = strdup(pw->pw_gecos); + newpw.pw_dir = strdup(pw->pw_dir); + newpw.pw_shell = strdup(pw->pw_shell); + + // Rewrite the file + rewind(fp); + rewrite_file(fname, fp, &newpw); + + fclose(fp); + + return 0; +} |