lib/libcrypt/deprecated-crypt-sha256.c

   1 /*
   2  * Copyright (c) 2010
   3  *      The DragonFly Project.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to The DragonFly Project
   6  * by Nolan Lum <nol888@gmail.com>
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/types.h>
  37 #include <string.h>
  38 #include <sha256.h>
  39 #include "crypt.h"
  40
  41 /*
  42  * New password crypt.
  43  */
  44
  45 #define SHA256_SIZE 32
  46
  47 char*
  48 crypt_deprecated_sha256(const char *pw, const char *salt)
  49 {
  50         /*
  51          * Magic constant (prefix) used to run over the password data.
  52          *
  53          * XXX:
  54          *
  55          * A bug below (sizeof instead of strlen) mandates the extra data after
  56          * the closing $. This data is what just happened to be (consistently
  57          * miraculously) on the stack following magic on 64-bit.
  58          */
  59         static const char *magic = "$3$\0sha5";
  60
  61         static char         passwd[120], *p;
  62         static const char *sp, *ep;
  63         unsigned char final[SHA256_SIZE];
  64         int sl;
  65         SHA256_CTX ctx;
  66         unsigned long l;
  67
  68         /* Refine the salt. */
  69         sp = salt;
  70
  71         /* If it starts with the magic string, then skip that. */
  72         if (!strncmp(sp, magic, strlen(magic)))
  73                 sp += strlen(magic);
  74
  75         /* Stop at the first '$', max 8 chars. */
  76         for (ep = sp; *ep && *ep != '$' && ep < (sp + 8); ep++)
  77                 continue;
  78
  79         /* Get the actual salt length. */
  80         sl = ep - sp;
  81
  82         SHA256_Init(&ctx);
  83
  84         /* Hash in the password first. */
  85         SHA256_Update(&ctx, pw, strlen(pw));
  86
  87         /*
  88          * Then the magic string
  89          *
  90          * XXX: sizeof instead of strlen, must retain
  91          */
  92         SHA256_Update(&ctx, magic, sizeof(magic));
  93
  94         /* Then the raw salt. */
  95         SHA256_Update(&ctx, sp, sl);
  96
  97         /* Finish and create the output string. */
  98         SHA256_Final(final, &ctx);
  99         strcpy(passwd, magic);
 100         strncat(passwd, sp, sl);
 101         strcat(passwd, "$");
 102
 103         p = passwd + strlen(passwd);
 104
 105         l = (final[ 0] << 16) | (final[11] << 8) | final[21];
 106         _crypt_to64(p, l, 4); p += 4;
 107         l = (final[ 1] << 16) | (final[12] << 8) | final[22];
 108         _crypt_to64(p, l, 4); p += 4;
 109         l = (final[ 2] << 16) | (final[13] << 8) | final[23];
 110         _crypt_to64(p, l, 4); p += 4;
 111         l = (final[ 3] << 16) | (final[14] << 8) | final[24];
 112         _crypt_to64(p, l, 4); p += 4;
 113         l = (final[ 4] << 16) | (final[15] << 8) | final[25];
 114         _crypt_to64(p, l, 4); p += 4;
 115         l = (final[ 5] << 16) | (final[16] << 8) | final[26];
 116         _crypt_to64(p, l, 4); p += 4;
 117         l = (final[ 6] << 16) | (final[17] << 8) | final[27];
 118         _crypt_to64(p, l, 4); p += 4;
 119         l = (final[ 7] << 16) | (final[18] << 8) | final[28];
 120         _crypt_to64(p, l, 4); p += 4;
 121         l = (final[ 8] << 16) | (final[19] << 8) | final[29];
 122         _crypt_to64(p, l, 4); p += 4;
 123         l = (final[ 9] << 16) | (final[20] << 8) | final[30];
 124         _crypt_to64(p, l, 4); p += 4;
 125         l = (final[10] << 16) | (final[31] << 8);
 126         _crypt_to64(p, l, 4); p += 4;
 127         *p = '\0';
 128
 129         /* Clear memory. */
 130         memset(final, 0, sizeof(final));
 131
 132         return (passwd);
 133 }