release/src/router/busybox/libbb/pw_encrypt.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9
  10 #include "libbb.h"
  11
  12 /* static const uint8_t ascii64[] =
  13  * "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  14  */
  15
  16 static int i64c(int i)
  17 {
  18         i &= 0x3f;
  19         if (i == 0)
  20                 return '.';
  21         if (i == 1)
  22                 return '/';
  23         if (i < 12)
  24                 return ('0' - 2 + i);
  25         if (i < 38)
  26                 return ('A' - 12 + i);
  27         return ('a' - 38 + i);
  28 }
  29
  30 int FAST_FUNC crypt_make_salt(char *p, int cnt /*, int x */)
  31 {
  32         /* was: x += ... */
  33         int x = getpid() + monotonic_us();
  34         do {
  35                 /* x = (x*1664525 + 1013904223) % 2^32 generator is lame
  36                  * (low-order bit is not "random", etc...),
  37                  * but for our purposes it is good enough */
  38                 x = x*1664525 + 1013904223;
  39                 /* BTW, Park and Miller's "minimal standard generator" is
  40                  * x = x*16807 % ((2^31)-1)
  41                  * It has no problem with visibly alternating lowest bit
  42                  * but is also weak in cryptographic sense + needs div,
  43                  * which needs more code (and slower) on many CPUs */
  44                 *p++ = i64c(x >> 16);
  45                 *p++ = i64c(x >> 22);
  46         } while (--cnt);
  47         *p = '\0';
  48         return x;
  49 }
  50
  51 char* FAST_FUNC crypt_make_pw_salt(char salt[MAX_PW_SALT_LEN], const char *algo)
  52 {
  53         int len = 2/2;
  54         char *salt_ptr = salt;
  55         if (algo[0] != 'd') { /* not des */
  56                 len = 8/2; /* so far assuming md5 */
  57                 *salt_ptr++ = '$';
  58                 *salt_ptr++ = '1';
  59                 *salt_ptr++ = '$';
  60 #if !ENABLE_USE_BB_CRYPT || ENABLE_USE_BB_CRYPT_SHA
  61                 if (algo[0] == 's') { /* sha */
  62                         salt[1] = '5' + (strcmp(algo, "sha512") == 0);
  63                         len = 16/2;
  64                 }
  65 #endif
  66         }
  67         crypt_make_salt(salt_ptr, len);
  68         return salt_ptr;
  69 }
  70
  71 #if ENABLE_USE_BB_CRYPT
  72
  73 static char*
  74 to64(char *s, unsigned v, int n)
  75 {
  76         while (--n >= 0) {
  77                 /* *s++ = ascii64[v & 0x3f]; */
  78                 *s++ = i64c(v);
  79                 v >>= 6;
  80         }
  81         return s;
  82 }
  83
  84 /*
  85  * DES and MD5 crypt implementations are taken from uclibc.
  86  * They were modified to not use static buffers.
  87  */
  88
  89 #include "pw_encrypt_des.c"
  90 #include "pw_encrypt_md5.c"
  91 #if ENABLE_USE_BB_CRYPT_SHA
  92 #include "pw_encrypt_sha.c"
  93 #endif
  94
  95 /* Other advanced crypt ids (TODO?): */
  96 /* $2$ or $2a$: Blowfish */
  97
  98 static struct const_des_ctx *des_cctx;
  99 static struct des_ctx *des_ctx;
 100
 101 /* my_crypt returns malloc'ed data */
 102 static char *my_crypt(const char *key, const char *salt)
 103 {
 104         /* MD5 or SHA? */
 105         if (salt[0] == '$' && salt[1] && salt[2] == '$') {
 106                 if (salt[1] == '1')
 107                         return md5_crypt(xzalloc(MD5_OUT_BUFSIZE), (unsigned char*)key, (unsigned char*)salt);
 108 #if ENABLE_USE_BB_CRYPT_SHA
 109                 if (salt[1] == '5' || salt[1] == '6')
 110                         return sha_crypt((char*)key, (char*)salt);
 111 #endif
 112         }
 113
 114         if (!des_cctx)
 115                 des_cctx = const_des_init();
 116         des_ctx = des_init(des_ctx, des_cctx);
 117         return des_crypt(des_ctx, xzalloc(DES_OUT_BUFSIZE), (unsigned char*)key, (unsigned char*)salt);
 118 }
 119
 120 /* So far nobody wants to have it public */
 121 static void my_crypt_cleanup(void)
 122 {
 123         free(des_cctx);
 124         free(des_ctx);
 125         des_cctx = NULL;
 126         des_ctx = NULL;
 127 }
 128
 129 char* FAST_FUNC pw_encrypt(const char *clear, const char *salt, int cleanup)
 130 {
 131         char *encrypted;
 132
 133         encrypted = my_crypt(clear, salt);
 134
 135         if (cleanup)
 136                 my_crypt_cleanup();
 137
 138         return encrypted;
 139 }
 140
 141 #else /* if !ENABLE_USE_BB_CRYPT */
 142
 143 char* FAST_FUNC pw_encrypt(const char *clear, const char *salt, int cleanup)
 144 {
 145         return xstrdup(crypt(clear, salt));
 146 }
 147
 148 #endif