postgresql/contrib/pgcrypto/crypt-gensalt.c
2010-09-20 22:08:53 +02:00

189 lines
4.4 KiB
C

/*
* Written by Solar Designer and placed in the public domain.
* See crypt_blowfish.c for more information.
*
* contrib/pgcrypto/crypt-gensalt.c
*
* This file contains salt generation functions for the traditional and
* other common crypt(3) algorithms, except for bcrypt which is defined
* entirely in crypt_blowfish.c.
*
* Put bcrypt generator also here as crypt-blowfish.c
* may not be compiled always. -- marko
*/
#include "postgres.h"
#include "px.h"
#include "px-crypt.h"
typedef unsigned int BF_word;
static unsigned char _crypt_itoa64[64 + 1] =
"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
char *
_crypt_gensalt_traditional_rn(unsigned long count,
const char *input, int size, char *output, int output_size)
{
if (size < 2 || output_size < 2 + 1 || (count && count != 25))
{
if (output_size > 0)
output[0] = '\0';
return NULL;
}
output[0] = _crypt_itoa64[(unsigned int) input[0] & 0x3f];
output[1] = _crypt_itoa64[(unsigned int) input[1] & 0x3f];
output[2] = '\0';
return output;
}
char *
_crypt_gensalt_extended_rn(unsigned long count,
const char *input, int size, char *output, int output_size)
{
unsigned long value;
/* Even iteration counts make it easier to detect weak DES keys from a look
* at the hash, so they should be avoided */
if (size < 3 || output_size < 1 + 4 + 4 + 1 ||
(count && (count > 0xffffff || !(count & 1))))
{
if (output_size > 0)
output[0] = '\0';
return NULL;
}
if (!count)
count = 725;
output[0] = '_';
output[1] = _crypt_itoa64[count & 0x3f];
output[2] = _crypt_itoa64[(count >> 6) & 0x3f];
output[3] = _crypt_itoa64[(count >> 12) & 0x3f];
output[4] = _crypt_itoa64[(count >> 18) & 0x3f];
value = (unsigned long) (unsigned char) input[0] |
((unsigned long) (unsigned char) input[1] << 8) |
((unsigned long) (unsigned char) input[2] << 16);
output[5] = _crypt_itoa64[value & 0x3f];
output[6] = _crypt_itoa64[(value >> 6) & 0x3f];
output[7] = _crypt_itoa64[(value >> 12) & 0x3f];
output[8] = _crypt_itoa64[(value >> 18) & 0x3f];
output[9] = '\0';
return output;
}
char *
_crypt_gensalt_md5_rn(unsigned long count,
const char *input, int size, char *output, int output_size)
{
unsigned long value;
if (size < 3 || output_size < 3 + 4 + 1 || (count && count != 1000))
{
if (output_size > 0)
output[0] = '\0';
return NULL;
}
output[0] = '$';
output[1] = '1';
output[2] = '$';
value = (unsigned long) (unsigned char) input[0] |
((unsigned long) (unsigned char) input[1] << 8) |
((unsigned long) (unsigned char) input[2] << 16);
output[3] = _crypt_itoa64[value & 0x3f];
output[4] = _crypt_itoa64[(value >> 6) & 0x3f];
output[5] = _crypt_itoa64[(value >> 12) & 0x3f];
output[6] = _crypt_itoa64[(value >> 18) & 0x3f];
output[7] = '\0';
if (size >= 6 && output_size >= 3 + 4 + 4 + 1)
{
value = (unsigned long) (unsigned char) input[3] |
((unsigned long) (unsigned char) input[4] << 8) |
((unsigned long) (unsigned char) input[5] << 16);
output[7] = _crypt_itoa64[value & 0x3f];
output[8] = _crypt_itoa64[(value >> 6) & 0x3f];
output[9] = _crypt_itoa64[(value >> 12) & 0x3f];
output[10] = _crypt_itoa64[(value >> 18) & 0x3f];
output[11] = '\0';
}
return output;
}
static unsigned char BF_itoa64[64 + 1] =
"./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
static void
BF_encode(char *dst, const BF_word *src, int size)
{
unsigned char *sptr = (unsigned char *) src;
unsigned char *end = sptr + size;
unsigned char *dptr = (unsigned char *) dst;
unsigned int c1,
c2;
do
{
c1 = *sptr++;
*dptr++ = BF_itoa64[c1 >> 2];
c1 = (c1 & 0x03) << 4;
if (sptr >= end)
{
*dptr++ = BF_itoa64[c1];
break;
}
c2 = *sptr++;
c1 |= c2 >> 4;
*dptr++ = BF_itoa64[c1];
c1 = (c2 & 0x0f) << 2;
if (sptr >= end)
{
*dptr++ = BF_itoa64[c1];
break;
}
c2 = *sptr++;
c1 |= c2 >> 6;
*dptr++ = BF_itoa64[c1];
*dptr++ = BF_itoa64[c2 & 0x3f];
} while (sptr < end);
}
char *
_crypt_gensalt_blowfish_rn(unsigned long count,
const char *input, int size, char *output, int output_size)
{
if (size < 16 || output_size < 7 + 22 + 1 ||
(count && (count < 4 || count > 31)))
{
if (output_size > 0)
output[0] = '\0';
return NULL;
}
if (!count)
count = 5;
output[0] = '$';
output[1] = '2';
output[2] = 'a';
output[3] = '$';
output[4] = '0' + count / 10;
output[5] = '0' + count % 10;
output[6] = '$';
BF_encode(&output[7], (BF_word *) input, 16);
output[7 + 22] = '\0';
return output;
}