| /* vi: set sw=4 ts=4: */ |
| /* |
| * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
| */ |
| |
| #include "busybox.h" |
| #include <syslog.h> |
| |
| static char crypt_passwd[128]; |
| |
| static int create_backup(const char *backup, FILE * fp); |
| static int new_password(const struct passwd *pw, int amroot, int algo); |
| static void set_filesize_limit(int blocks); |
| |
| |
| static int get_algo(char *a) |
| { |
| int x = 1; /* standard: MD5 */ |
| |
| if (strcasecmp(a, "des") == 0) |
| x = 0; |
| return x; |
| } |
| |
| |
| static int update_passwd(const struct passwd *pw, const char *crypt_pw) |
| { |
| char filename[1024]; |
| char buf[1025]; |
| char buffer[80]; |
| char username[32]; |
| char *pw_rest; |
| int mask; |
| int continued; |
| FILE *fp; |
| FILE *out_fp; |
| struct stat sb; |
| struct flock lock; |
| |
| #if ENABLE_FEATURE_SHADOWPASSWDS |
| if (access(bb_path_shadow_file, F_OK) == 0) { |
| snprintf(filename, sizeof filename, "%s", bb_path_shadow_file); |
| } else |
| #endif |
| { |
| snprintf(filename, sizeof filename, "%s", bb_path_passwd_file); |
| } |
| |
| fp = fopen(filename, "r+"); |
| if (fp == 0 || fstat(fileno(fp), &sb)) { |
| /* return 0; */ |
| return 1; |
| } |
| |
| /* 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(fileno(fp), F_SETLK, &lock) < 0) { |
| bb_perror_msg("%s", filename); |
| return 1; |
| } |
| lock.l_type = F_UNLCK; |
| |
| snprintf(buf, sizeof buf, "%s-", filename); |
| if (create_backup(buf, fp)) { |
| fcntl(fileno(fp), F_SETLK, &lock); |
| fclose(fp); |
| return 1; |
| } |
| snprintf(buf, sizeof buf, "%s+", filename); |
| mask = umask(0777); |
| out_fp = fopen(buf, "w"); |
| umask(mask); |
| if ((!out_fp) || (fchmod(fileno(out_fp), sb.st_mode & 0777)) |
| || (fchown(fileno(out_fp), sb.st_uid, sb.st_gid))) { |
| fcntl(fileno(fp), F_SETLK, &lock); |
| fclose(fp); |
| fclose(out_fp); |
| return 1; |
| } |
| |
| continued = 0; |
| snprintf(username, sizeof username, "%s:", pw->pw_name); |
| rewind(fp); |
| while (!feof(fp)) { |
| fgets(buffer, sizeof buffer, fp); |
| if (!continued) { /* Check to see if we're updating this line. */ |
| if (strncmp(username, buffer, strlen(username)) == 0) { |
| /* we have a match. */ |
| pw_rest = strchr(buffer, ':'); |
| *pw_rest++ = '\0'; |
| pw_rest = strchr(pw_rest, ':'); |
| fprintf(out_fp, "%s:%s%s", buffer, crypt_pw, pw_rest); |
| } else { |
| fputs(buffer, out_fp); |
| } |
| } else { |
| fputs(buffer, out_fp); |
| } |
| if (buffer[strlen(buffer) - 1] == '\n') { |
| continued = 0; |
| } else { |
| continued = 1; |
| } |
| memset(buffer, 0, sizeof buffer); |
| } |
| |
| if (fflush(out_fp) || fsync(fileno(out_fp)) || fclose(out_fp)) { |
| unlink(buf); |
| fcntl(fileno(fp), F_SETLK, &lock); |
| fclose(fp); |
| return 1; |
| } |
| if (rename(buf, filename) < 0) { |
| fcntl(fileno(fp), F_SETLK, &lock); |
| fclose(fp); |
| return 1; |
| } else { |
| fcntl(fileno(fp), F_SETLK, &lock); |
| fclose(fp); |
| return 0; |
| } |
| } |
| |
| |
| int passwd_main(int argc, char **argv) |
| { |
| enum { |
| OPT_algo = 0x1, /* -a - password algorithm */ |
| OPT_lock = 0x2, /* -l - lock account */ |
| OPT_unlock = 0x4, /* -u - unlock account */ |
| OPT_delete = 0x8, /* -d - delete password */ |
| OPT_lud = 0xe, |
| }; |
| unsigned opt; |
| char *opt_a; |
| int amroot; |
| char *cp; |
| char *np; |
| char *name; |
| char *myname; |
| int algo = 1; |
| const struct passwd *pw; |
| |
| amroot = (getuid() == 0); |
| openlog("passwd", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH); |
| opt = getopt32(argc, argv, "a:lud", &opt_a); |
| argc -= optind; |
| argv += optind; |
| if (opt & OPT_algo) algo = get_algo(opt_a); // -a |
| if ((opt & OPT_lud) && (!argc || !amroot)) |
| bb_show_usage(); |
| |
| myname = xstrdup(bb_getpwuid(NULL, getuid(), -1)); |
| name = myname; |
| if (argc) name = argv[0]; |
| |
| pw = getpwnam(name); |
| if (!pw) { |
| bb_error_msg_and_die("unknown user %s", name); |
| } |
| if (!amroot && pw->pw_uid != getuid()) { |
| syslog(LOG_WARNING, "can't change pwd for '%s'", name); |
| bb_error_msg_and_die("permission denied"); |
| } |
| if (ENABLE_FEATURE_SHADOWPASSWDS) { |
| struct spwd *sp = getspnam(name); |
| if (!sp) bb_error_msg_and_die("unknown user %s", name); |
| cp = sp->sp_pwdp; |
| } else cp = pw->pw_passwd; |
| |
| np = name; |
| safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd)); |
| if (!(opt & OPT_lud)) { |
| if (!amroot) { |
| if (cp[0] == '!') { |
| syslog(LOG_WARNING, "password locked for '%s'", np); |
| bb_error_msg_and_die("the password for %s cannot be changed", np); |
| } |
| } |
| printf("Changing password for %s\n", name); |
| if (new_password(pw, amroot, algo)) { |
| bb_error_msg_and_die("the password for %s is unchanged", name); |
| } |
| } else if (opt & OPT_lock) { |
| if (crypt_passwd[0] != '!') { |
| memmove(&crypt_passwd[1], crypt_passwd, |
| sizeof crypt_passwd - 1); |
| crypt_passwd[sizeof crypt_passwd - 1] = '\0'; |
| crypt_passwd[0] = '!'; |
| } |
| } else if (opt & OPT_unlock) { |
| if (crypt_passwd[0] == '!') { |
| memmove(crypt_passwd, &crypt_passwd[1], |
| sizeof crypt_passwd - 1); |
| } |
| } else if (opt & OPT_delete) { |
| crypt_passwd[0] = '\0'; |
| } |
| set_filesize_limit(30000); |
| signal(SIGHUP, SIG_IGN); |
| signal(SIGINT, SIG_IGN); |
| signal(SIGQUIT, SIG_IGN); |
| umask(077); |
| xsetuid(0); |
| if (!update_passwd(pw, crypt_passwd)) { |
| syslog(LOG_INFO, "password for '%s' changed by user '%s'", name, |
| myname); |
| puts("Password changed"); |
| } else { |
| syslog(LOG_WARNING, "cannot update password file"); |
| bb_error_msg_and_die("cannot update password file"); |
| } |
| if (ENABLE_FEATURE_CLEAN_UP) free(myname); |
| return 0; |
| } |
| |
| |
| |
| static int create_backup(const char *backup, FILE * fp) |
| { |
| struct stat sb; |
| struct utimbuf ub; |
| FILE *bkfp; |
| int c, mask; |
| |
| if (fstat(fileno(fp), &sb)) |
| /* return -1; */ |
| return 1; |
| |
| mask = umask(077); |
| bkfp = fopen(backup, "w"); |
| umask(mask); |
| if (!bkfp) |
| /* return -1; */ |
| return 1; |
| |
| /* TODO: faster copy, not one-char-at-a-time. --marekm */ |
| rewind(fp); |
| while ((c = getc(fp)) != EOF) { |
| if (putc(c, bkfp) == EOF) |
| break; |
| } |
| if (c != EOF || fflush(bkfp)) { |
| fclose(bkfp); |
| /* return -1; */ |
| return 1; |
| } |
| if (fclose(bkfp)) |
| /* return -1; */ |
| return 1; |
| |
| ub.actime = sb.st_atime; |
| ub.modtime = sb.st_mtime; |
| utime(backup, &ub); |
| return 0; |
| } |
| |
| static int i64c(int i) |
| { |
| if (i <= 0) |
| return ('.'); |
| if (i == 1) |
| return ('/'); |
| if (i >= 2 && i < 12) |
| return ('0' - 2 + i); |
| if (i >= 12 && i < 38) |
| return ('A' - 12 + i); |
| if (i >= 38 && i < 63) |
| return ('a' - 38 + i); |
| return ('z'); |
| } |
| |
| static char *crypt_make_salt(void) |
| { |
| time_t now; |
| static unsigned long x; |
| static char result[3]; |
| |
| time(&now); |
| x += now + getpid() + clock(); |
| result[0] = i64c(((x >> 18) ^ (x >> 6)) & 077); |
| result[1] = i64c(((x >> 12) ^ x) & 077); |
| result[2] = '\0'; |
| return result; |
| } |
| |
| |
| static int new_password(const struct passwd *pw, int amroot, int algo) |
| { |
| char *clear; |
| char *cipher; |
| char *cp; |
| char salt[12]; /* "$N$XXXXXXXX" or "XX" */ |
| char orig[200]; |
| char pass[200]; |
| |
| if (!amroot && crypt_passwd[0]) { |
| clear = bb_askpass(0, "Old password:"); |
| if (!clear) { |
| /* return -1; */ |
| return 1; |
| } |
| cipher = pw_encrypt(clear, crypt_passwd); |
| if (strcmp(cipher, crypt_passwd) != 0) { |
| syslog(LOG_WARNING, "incorrect password for '%s'", |
| pw->pw_name); |
| bb_do_delay(FAIL_DELAY); |
| puts("Incorrect password"); |
| /* return -1; */ |
| return 1; |
| } |
| safe_strncpy(orig, clear, sizeof(orig)); |
| memset(clear, 0, strlen(clear)); |
| memset(cipher, 0, strlen(cipher)); |
| } else { |
| orig[0] = '\0'; |
| } |
| cp = bb_askpass(0, "Enter the new password (minimum of 5 characters).\n" |
| "Please use a combination of upper and lower case letters and numbers.\n" |
| "Enter new password: "); |
| if (!cp ) { |
| memset(orig, 0, sizeof orig); |
| /* return -1; */ |
| return 1; |
| } |
| safe_strncpy(pass, cp, sizeof(pass)); |
| memset(cp, 0, strlen(cp)); |
| /* if (!obscure(orig, pass, pw)) { */ |
| if (obscure(orig, pass, pw)) { |
| if (amroot) { |
| puts("\nWarning: weak password (continuing)"); |
| } else { |
| /* return -1; */ |
| return 1; |
| } |
| } |
| cp = bb_askpass(0, "Re-enter new password: "); |
| if (!cp) { |
| memset(orig, 0, sizeof orig); |
| /* return -1; */ |
| return 1; |
| } |
| if (strcmp(cp, pass)) { |
| puts("Passwords do not match"); |
| /* return -1; */ |
| return 1; |
| } |
| memset(cp, 0, strlen(cp)); |
| memset(orig, 0, sizeof(orig)); |
| memset(salt, 0, sizeof(salt)); |
| |
| if (algo == 1) { |
| strcpy(salt, "$1$"); |
| strcat(salt, crypt_make_salt()); |
| strcat(salt, crypt_make_salt()); |
| strcat(salt, crypt_make_salt()); |
| } |
| |
| strcat(salt, crypt_make_salt()); |
| cp = pw_encrypt(pass, salt); |
| |
| memset(pass, 0, sizeof pass); |
| safe_strncpy(crypt_passwd, cp, sizeof(crypt_passwd)); |
| return 0; |
| } |
| |
| static void set_filesize_limit(int blocks) |
| { |
| struct rlimit rlimit_fsize; |
| |
| rlimit_fsize.rlim_cur = rlimit_fsize.rlim_max = 512L * blocks; |
| setrlimit(RLIMIT_FSIZE, &rlimit_fsize); |
| } |