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

144 lines
3.1 KiB
C

/*
* pgp-mpi.c
* OpenPGP MPI helper 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-mpi.c
*/
#include "postgres.h"
#include "px.h"
#include "mbuf.h"
#include "pgp.h"
int
pgp_mpi_alloc(int bits, PGP_MPI **mpi)
{
PGP_MPI *n;
int len = (bits + 7) / 8;
if (bits < 0 || bits > 0xFFFF)
{
px_debug("pgp_mpi_alloc: unreasonable request: bits=%d", bits);
return PXE_PGP_CORRUPT_DATA;
}
n = px_alloc(sizeof(*n) + len);
n->bits = bits;
n->bytes = len;
n->data = (uint8 *) (n) + sizeof(*n);
*mpi = n;
return 0;
}
int
pgp_mpi_create(uint8 *data, int bits, PGP_MPI **mpi)
{
int res;
PGP_MPI *n;
res = pgp_mpi_alloc(bits, &n);
if (res < 0)
return res;
memcpy(n->data, data, n->bytes);
*mpi = n;
return 0;
}
int
pgp_mpi_free(PGP_MPI *mpi)
{
if (mpi == NULL)
return 0;
memset(mpi, 0, sizeof(*mpi) + mpi->bytes);
px_free(mpi);
return 0;
}
int
pgp_mpi_read(PullFilter *src, PGP_MPI **mpi)
{
int res;
uint8 hdr[2];
int bits;
PGP_MPI *n;
res = pullf_read_fixed(src, 2, hdr);
if (res < 0)
return res;
bits = ((unsigned) hdr[0] << 8) + hdr[1];
res = pgp_mpi_alloc(bits, &n);
if (res < 0)
return res;
res = pullf_read_fixed(src, n->bytes, n->data);
if (res < 0)
pgp_mpi_free(n);
else
*mpi = n;
return res;
}
int
pgp_mpi_write(PushFilter *dst, PGP_MPI *n)
{
int res;
uint8 buf[2];
buf[0] = n->bits >> 8;
buf[1] = n->bits & 0xFF;
res = pushf_write(dst, buf, 2);
if (res >= 0)
res = pushf_write(dst, n->data, n->bytes);
return res;
}
int
pgp_mpi_hash(PX_MD *md, PGP_MPI *n)
{
uint8 buf[2];
buf[0] = n->bits >> 8;
buf[1] = n->bits & 0xFF;
px_md_update(md, buf, 2);
px_md_update(md, n->data, n->bytes);
return 0;
}
unsigned
pgp_mpi_cksum(unsigned cksum, PGP_MPI *n)
{
int i;
cksum += n->bits >> 8;
cksum += n->bits & 0xFF;
for (i = 0; i < n->bytes; i++)
cksum += n->data[i];
return cksum & 0xFFFF;
}