diff options
| -rw-r--r-- | libbb/update_passwd.c | 119 | ||||
| -rw-r--r-- | loginutils/chpasswd.c | 77 |
2 files changed, 196 insertions, 0 deletions
diff --git a/libbb/update_passwd.c b/libbb/update_passwd.c new file mode 100644 index 000000000..5572db547 --- /dev/null +++ b/libbb/update_passwd.c @@ -0,0 +1,119 @@ +/* vi: set sw=4 ts=4: */ +/* + * update_passwd + * + * update_passwd is a common function for passwd and chpasswd applets; + * it is responsible for updating password file (i.e. /etc/passwd or + * /etc/shadow) for a given user and password. + * + * Moved from loginutils/passwd.c by Alexander Shishkin <virtuoso@slind.org> + */ + +#include "libbb.h" + +int update_passwd(const char *filename, const char *username, + const char *new_pw) +{ + struct stat sb; + struct flock lock; + FILE *old_fp; + FILE *new_fp; + char *new_name; + char *last_char; + unsigned user_len; + int old_fd; + int new_fd; + int i; + int cnt = 0; + int ret = 1; /* failure */ + + /* New passwd file, "/etc/passwd+" for now */ + new_name = xasprintf("%s+", filename); + last_char = &new_name[strlen(new_name)-1]; + username = xasprintf("%s:", username); + user_len = strlen(username); + + old_fp = fopen(filename, "r+"); + if (!old_fp) + goto free_mem; + old_fd = fileno(old_fp); + + /* Try to create "/etc/passwd+". Wait if it exists. */ + i = 30; + do { + // FIXME: on last iteration try w/o O_EXCL but with O_TRUNC? + new_fd = open(new_name, O_WRONLY|O_CREAT|O_EXCL,0600); + if (new_fd >= 0) goto created; + if (errno != EEXIST) break; + usleep(100000); /* 0.1 sec */ + } while (--i); + bb_perror_msg("cannot create '%s'", new_name); + goto close_old_fp; + + created: + if (!fstat(old_fd, &sb)) { + fchmod(new_fd, sb.st_mode & 0777); /* ignore errors */ + fchown(new_fd, sb.st_uid, sb.st_gid); + } + new_fp = fdopen(new_fd, "w"); + if (!new_fp) { + close(new_fd); + goto unlink_new; + } + + /* Backup file is "/etc/passwd-" */ + last_char[0] = '-'; + /* Delete old one, create new as a hardlink to current */ + i = (unlink(new_name) && errno != ENOENT); + if (i || link(filename, new_name)) + bb_perror_msg("warning: cannot create backup copy '%s'", new_name); + last_char[0] = '+'; + + /* Lock the password file before updating */ + lock.l_type = F_WRLCK; + lock.l_whence = SEEK_SET; + lock.l_start = 0; + lock.l_len = 0; + if (fcntl(old_fd, F_SETLK, &lock) < 0) + bb_perror_msg("warning: cannot lock '%s'", filename); + lock.l_type = F_UNLCK; + + /* Read current password file, write updated one */ + while (1) { + char *line = xmalloc_fgets(old_fp); + if (!line) break; /* EOF/error */ + if (strncmp(username, line, user_len) == 0) { + /* we have a match with "username:"... */ + const char *cp = line + user_len; + /* now cp -> old passwd, skip it: */ + cp = strchr(cp, ':'); + if (!cp) cp = ""; + /* now cp -> ':' after old passwd or -> "" */ + fprintf(new_fp, "%s%s%s", username, new_pw, cp); + cnt++; + } else + fputs(line, new_fp); + free(line); + } + fcntl(old_fd, F_SETLK, &lock); + + /* We do want all of them to execute, thus | instead of || */ + if ((ferror(old_fp) | fflush(new_fp) | fsync(new_fd) | fclose(new_fp)) + || rename(new_name, filename) + ) { + /* At least one of those failed */ + goto unlink_new; + } + ret = cnt; /* whee, success! */ + + unlink_new: + if (ret) unlink(new_name); + + close_old_fp: + fclose(old_fp); + + free_mem: + if (ENABLE_FEATURE_CLEAN_UP) free(new_name); + if (ENABLE_FEATURE_CLEAN_UP) free((char*)username); + return ret; +} diff --git a/loginutils/chpasswd.c b/loginutils/chpasswd.c new file mode 100644 index 000000000..124fc86e2 --- /dev/null +++ b/loginutils/chpasswd.c @@ -0,0 +1,77 @@ +/* vi: set sw=4 ts=4: */ +/* + * chpasswd.c + * + * Written for SLIND (from passwd.c) by Alexander Shishkin <virtuoso@slind.org> + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +#include "libbb.h" + +#if ENABLE_GETOPT_LONG +#include <getopt.h> + +static const struct option chpasswd_opts[] = { + { "encrypted", no_argument, NULL, 'e' }, + { "md5", no_argument, NULL, 'm' }, + { NULL, 0, NULL, 0 } +}; +#endif + +#define OPT_ENC 1 +#define OPT_MD5 2 + +int chpasswd_main(int argc, char **argv); +int chpasswd_main(int argc, char **argv) +{ + char *name, *pass; + char salt[sizeof("$N$XXXXXXXX")]; + int opt, rc; + int rnd = rnd; /* we *want* it to be non-initialized! */ + const char *pwfile = bb_path_passwd_file; + + if (getuid() != 0) + bb_error_msg_and_die(bb_msg_perm_denied_are_you_root); + +#if ENABLE_FEATURE_SHADOWPASSWDS + if (access(bb_path_shadow_file, F_OK) == 0) + pwfile = bb_path_shadow_file; +#endif + + opt_complementary = "m--e"; + USE_GETOPT_LONG(applet_long_options = chpasswd_opts;) + opt = getopt32(argc, argv, "em"); + + while ((name = xmalloc_getline(stdin)) != NULL) { + pass = strchr(name, ':'); + if (!pass) + bb_error_msg_and_die("missing new password"); + *pass++ = '\0'; + + //if (!getpwnam(name)) + // bb_error_msg_and_die("unknown user %s", name); + + if (!(opt & OPT_ENC)) { + rnd = crypt_make_salt(salt, 1, rnd); + if (opt & OPT_MD5) { + strcpy(salt, "$1$"); + rnd = crypt_make_salt(salt + 3, 4, rnd); + } + pass = pw_encrypt(pass, salt); + } + + rc = update_passwd(pwfile, name, pass); + /* LOGMODE_BOTH logs to syslog */ + logmode = LOGMODE_BOTH; + if (rc < 0) + bb_error_msg_and_die("an error occurred updating %s", pwfile); + if (rc > 0) + bb_info_msg("Password for '%s' changed", name); + else + bb_info_msg("User '%s' not found", name); + logmode = LOGMODE_STDIO; + free(name); + } + + return 0; +} |