loginutils/cryptpw.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * cryptpw.c - output a crypt(3)ed password to stdout.
   4  *
   5  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   6  *
   7  * Cooked from passwd.c by Thomas Lundquist <thomasez@zelow.no>
   8  * mkpasswd compatible options added by Bernhard Reutner-Fischer
   9  *
  10  * Licensed under GPLv2, see file LICENSE in this source tree.
  11  */
  12 //config:config CRYPTPW
  13 //config:       bool "cryptpw (15 kb)"
  14 //config:       default y
  15 //config:       help
  16 //config:       Encrypts the given password with the crypt(3) libc function
  17 //config:       using the given salt.
  18 //config:
  19 //config:config MKPASSWD
  20 //config:       bool "mkpasswd (16 kb)"
  21 //config:       default y
  22 //config:       help
  23 //config:       Encrypts the given password with the crypt(3) libc function
  24 //config:       using the given salt. Debian has this utility under mkpasswd
  25 //config:       name. Busybox provides mkpasswd as an alias for cryptpw.
  26
  27 //applet:IF_CRYPTPW( APPLET_NOEXEC(cryptpw,  cryptpw, BB_DIR_USR_BIN, BB_SUID_DROP, cryptpw))
  28 //                   APPLET_NOEXEC:name      main     location        suid_type     help
  29 //applet:IF_MKPASSWD(APPLET_NOEXEC(mkpasswd, cryptpw, BB_DIR_USR_BIN, BB_SUID_DROP, cryptpw))
  30
  31 //kbuild:lib-$(CONFIG_CRYPTPW) += cryptpw.o
  32 //kbuild:lib-$(CONFIG_MKPASSWD) += cryptpw.o
  33
  34 //usage:#define cryptpw_trivial_usage
  35 //usage:       "[-P FD] [-m TYPE] [-S SALT] [PASSWORD] [SALT]"
  36 /* We do support -s, we just don't mention it */
  37 //usage:#define cryptpw_full_usage "\n\n"
  38 //usage:       "Print crypt(3) hashed PASSWORD\n"
  39 //usage:     "\n        -P N    Read password from fd N"
  40 /* //usage:  "\n        -s      Use stdin; like -P0" */
  41 //usage:     "\n        -m TYPE "CRYPT_METHODS_HELP_STR
  42 //usage:     "\n        -S SALT"
  43
  44 #include "libbb.h"
  45
  46 /* Debian has 'mkpasswd' utility, manpage says:
  47
  48 NAME
  49     mkpasswd - Overfeatured front end to crypt(3)
  50 SYNOPSIS
  51     mkpasswd PASSWORD SALT
  52 ...
  53 OPTIONS
  54 -S, --salt=STRING
  55     Use the STRING as salt. It must not  contain  prefixes  such  as
  56     $1$.
  57 -R, --rounds=NUMBER
  58     Use NUMBER rounds. This argument is ignored if the method
  59     chosen does not support variable rounds. For the OpenBSD Blowfish
  60     method this is the logarithm of the number of rounds.
  61 -m, --method=TYPE
  62     Compute the password using the TYPE method. If TYPE is 'help'
  63     then the available methods are printed.
  64 -P, --password-fd=NUM
  65     Read the password from file descriptor NUM instead of using getpass(3).
  66     If the file descriptor is not connected to a tty then
  67     no other message than the hashed password is printed on stdout.
  68 -s, --stdin
  69     Like --password-fd=0.
  70 ENVIRONMENT
  71     $MKPASSWD_OPTIONS
  72     A list of options which will be evaluated before the ones
  73     specified on the command line.
  74 BUGS
  75     This program suffers of a bad case of featuritis.
  76     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  77
  78 Very true...
  79
  80 cryptpw was in bbox before this gem, so we retain it, and alias mkpasswd
  81 to cryptpw. -a option (alias for -m) came from cryptpw.
  82 */
  83
  84 int cryptpw_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  85 int cryptpw_main(int argc UNUSED_PARAM, char **argv)
  86 {
  87         /* Supports: cryptpw -m sha256 PASS 'rounds=999999999$SALT' */
  88         char salt[MAX_PW_SALT_LEN + sizeof("rounds=999999999$")];
  89         char *salt_ptr;
  90         char *password;
  91         const char *opt_m, *opt_S;
  92         int fd;
  93
  94 #if ENABLE_LONG_OPTS
  95         static const char mkpasswd_longopts[] ALIGN1 =
  96                 "stdin\0"       No_argument       "s"
  97                 "password-fd\0" Required_argument "P"
  98                 "salt\0"        Required_argument "S"
  99                 "method\0"      Required_argument "m"
 100         ;
 101 #endif
 102         fd = STDIN_FILENO;
 103         opt_m = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
 104         opt_S = NULL;
 105         /* at most two non-option arguments; -P NUM */
 106         getopt32long(argv, "^" "sP:+S:m:a:" "\0" "?2",
 107                         mkpasswd_longopts,
 108                         &fd, &opt_S, &opt_m, &opt_m
 109         );
 110         argv += optind;
 111
 112         /* have no idea how to handle -s... */
 113
 114         if (argv[0] && !opt_S)
 115                 opt_S = argv[1];
 116
 117         salt_ptr = crypt_make_pw_salt(salt, opt_m);
 118         if (opt_S)
 119                 /* put user's data after the "$N$" prefix */
 120                 safe_strncpy(salt_ptr, opt_S, sizeof(salt) - (sizeof("$N$")-1));
 121
 122         xmove_fd(fd, STDIN_FILENO);
 123
 124         password = argv[0];
 125         if (!password) {
 126                 /* Only mkpasswd, and only from tty, prompts.
 127                  * Otherwise it is a plain read. */
 128                 password = (ENABLE_MKPASSWD && applet_name[0] == 'm' && isatty(STDIN_FILENO))
 129                         ? bb_ask_noecho_stdin("Password: ")
 130                         : xmalloc_fgetline(stdin)
 131                 ;
 132                 /* may still be NULL on EOF/error */
 133         }
 134
 135         if (password)
 136                 puts(pw_encrypt(password, salt, 1));
 137
 138         return EXIT_SUCCESS;
 139 }