postgresql/contrib/pgcrypto/pgp-s2k.c
Peter Eisentraut 10a3b165a3 pgcrypto: Make header files stand alone
pgp.h used to require including mbuf.h and px.h first.  Include those in
pgp.h, so that it can be used without prerequisites.  Remove mbuf.h
inclusions in .c files where mbuf.h features are not used
directly.  (px.h was always used.)
2014-01-09 06:44:24 -05:00

296 lines
5.7 KiB
C

/*
* pgp-s2k.c
* OpenPGP string2key functions.
*
* Copyright (c) 2005 Marko Kreen
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* contrib/pgcrypto/pgp-s2k.c
*/
#include "postgres.h"
#include "px.h"
#include "pgp.h"
static int
calc_s2k_simple(PGP_S2K *s2k, PX_MD *md, const uint8 *key,
unsigned key_len)
{
unsigned md_rlen;
uint8 buf[PGP_MAX_DIGEST];
unsigned preload;
unsigned remain;
uint8 *dst = s2k->key;
md_rlen = px_md_result_size(md);
remain = s2k->key_len;
preload = 0;
while (remain > 0)
{
px_md_reset(md);
if (preload)
{
memset(buf, 0, preload);
px_md_update(md, buf, preload);
}
preload++;
px_md_update(md, key, key_len);
px_md_finish(md, buf);
if (remain > md_rlen)
{
memcpy(dst, buf, md_rlen);
dst += md_rlen;
remain -= md_rlen;
}
else
{
memcpy(dst, buf, remain);
remain = 0;
}
}
return 0;
}
static int
calc_s2k_salted(PGP_S2K *s2k, PX_MD *md, const uint8 *key, unsigned key_len)
{
unsigned md_rlen;
uint8 buf[PGP_MAX_DIGEST];
unsigned preload = 0;
uint8 *dst;
unsigned remain;
md_rlen = px_md_result_size(md);
dst = s2k->key;
remain = s2k->key_len;
while (remain > 0)
{
px_md_reset(md);
if (preload > 0)
{
memset(buf, 0, preload);
px_md_update(md, buf, preload);
}
preload++;
px_md_update(md, s2k->salt, PGP_S2K_SALT);
px_md_update(md, key, key_len);
px_md_finish(md, buf);
if (remain > md_rlen)
{
memcpy(dst, buf, md_rlen);
remain -= md_rlen;
dst += md_rlen;
}
else
{
memcpy(dst, buf, remain);
remain = 0;
}
}
return 0;
}
static int
calc_s2k_iter_salted(PGP_S2K *s2k, PX_MD *md, const uint8 *key,
unsigned key_len)
{
unsigned md_rlen;
uint8 buf[PGP_MAX_DIGEST];
uint8 *dst;
unsigned preload = 0;
unsigned remain,
c,
cval,
curcnt,
count;
cval = s2k->iter;
count = ((unsigned) 16 + (cval & 15)) << ((cval >> 4) + 6);
md_rlen = px_md_result_size(md);
remain = s2k->key_len;
dst = s2k->key;
while (remain > 0)
{
px_md_reset(md);
if (preload)
{
memset(buf, 0, preload);
px_md_update(md, buf, preload);
}
preload++;
px_md_update(md, s2k->salt, PGP_S2K_SALT);
px_md_update(md, key, key_len);
curcnt = PGP_S2K_SALT + key_len;
while (curcnt < count)
{
if (curcnt + PGP_S2K_SALT < count)
c = PGP_S2K_SALT;
else
c = count - curcnt;
px_md_update(md, s2k->salt, c);
curcnt += c;
if (curcnt + key_len < count)
c = key_len;
else if (curcnt < count)
c = count - curcnt;
else
break;
px_md_update(md, key, c);
curcnt += c;
}
px_md_finish(md, buf);
if (remain > md_rlen)
{
memcpy(dst, buf, md_rlen);
remain -= md_rlen;
dst += md_rlen;
}
else
{
memcpy(dst, buf, remain);
remain = 0;
}
}
return 0;
}
/*
* Decide S2K_ISALTED iteration count
*
* Too small: weak
* Too big: slow
* gpg defaults to 96 => 65536 iters
* let it float a bit: 96 + 32 => 262144 iters
*/
static int
decide_count(unsigned rand_byte)
{
return 96 + (rand_byte & 0x1F);
}
int
pgp_s2k_fill(PGP_S2K *s2k, int mode, int digest_algo)
{
int res = 0;
uint8 tmp;
s2k->mode = mode;
s2k->digest_algo = digest_algo;
switch (s2k->mode)
{
case 0:
break;
case 1:
res = px_get_pseudo_random_bytes(s2k->salt, PGP_S2K_SALT);
break;
case 3:
res = px_get_pseudo_random_bytes(s2k->salt, PGP_S2K_SALT);
if (res < 0)
break;
res = px_get_pseudo_random_bytes(&tmp, 1);
if (res < 0)
break;
s2k->iter = decide_count(tmp);
break;
default:
res = PXE_PGP_BAD_S2K_MODE;
}
return res;
}
int
pgp_s2k_read(PullFilter *src, PGP_S2K *s2k)
{
int res = 0;
GETBYTE(src, s2k->mode);
GETBYTE(src, s2k->digest_algo);
switch (s2k->mode)
{
case 0:
break;
case 1:
res = pullf_read_fixed(src, 8, s2k->salt);
break;
case 3:
res = pullf_read_fixed(src, 8, s2k->salt);
if (res < 0)
break;
GETBYTE(src, s2k->iter);
break;
default:
res = PXE_PGP_BAD_S2K_MODE;
}
return res;
}
int
pgp_s2k_process(PGP_S2K *s2k, int cipher, const uint8 *key, int key_len)
{
int res;
PX_MD *md;
s2k->key_len = pgp_get_cipher_key_size(cipher);
if (s2k->key_len <= 0)
return PXE_PGP_UNSUPPORTED_CIPHER;
res = pgp_load_digest(s2k->digest_algo, &md);
if (res < 0)
return res;
switch (s2k->mode)
{
case 0:
res = calc_s2k_simple(s2k, md, key, key_len);
break;
case 1:
res = calc_s2k_salted(s2k, md, key, key_len);
break;
case 3:
res = calc_s2k_iter_salted(s2k, md, key, key_len);
break;
default:
res = PXE_PGP_BAD_S2K_MODE;
}
px_md_free(md);
return res;
}