contrib/pgcrypto/pgp-mpi.c

   1 /*
   2  * pgp-mpi.c
   3  *        OpenPGP MPI helper functions.
   4  *
   5  * Copyright (c) 2005 Marko Kreen
   6  * All rights reserved.
   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  * 1. Redistributions of source code must retain the above copyright
  12  *        notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *        notice, this list of conditions and the following disclaimer in the
  15  *        documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * contrib/pgcrypto/pgp-mpi.c
  30  */
  31 #include "postgres.h"
  32
  33 #include "pgp.h"
  34 #include "px.h"
  35
  36 int
  37 pgp_mpi_alloc(int bits, PGP_MPI **mpi)
  38 {
  39         PGP_MPI    *n;
  40         int                     len = (bits + 7) / 8;
  41
  42         if (bits < 0 || bits > 0xFFFF)
  43         {
  44                 px_debug("pgp_mpi_alloc: unreasonable request: bits=%d", bits);
  45                 return PXE_PGP_CORRUPT_DATA;
  46         }
  47         n = palloc(sizeof(*n) + len);
  48         n->bits = bits;
  49         n->bytes = len;
  50         n->data = (uint8 *) (n) + sizeof(*n);
  51         *mpi = n;
  52         return 0;
  53 }
  54
  55 int
  56 pgp_mpi_create(uint8 *data, int bits, PGP_MPI **mpi)
  57 {
  58         int                     res;
  59         PGP_MPI    *n;
  60
  61         res = pgp_mpi_alloc(bits, &n);
  62         if (res < 0)
  63                 return res;
  64         memcpy(n->data, data, n->bytes);
  65         *mpi = n;
  66         return 0;
  67 }
  68
  69 int
  70 pgp_mpi_free(PGP_MPI *mpi)
  71 {
  72         if (mpi == NULL)
  73                 return 0;
  74         px_memset(mpi, 0, sizeof(*mpi) + mpi->bytes);
  75         pfree(mpi);
  76         return 0;
  77 }
  78
  79 int
  80 pgp_mpi_read(PullFilter *src, PGP_MPI **mpi)
  81 {
  82         int                     res;
  83         uint8           hdr[2];
  84         int                     bits;
  85         PGP_MPI    *n;
  86
  87         res = pullf_read_fixed(src, 2, hdr);
  88         if (res < 0)
  89                 return res;
  90         bits = ((unsigned) hdr[0] << 8) + hdr[1];
  91
  92         res = pgp_mpi_alloc(bits, &n);
  93         if (res < 0)
  94                 return res;
  95
  96         res = pullf_read_fixed(src, n->bytes, n->data);
  97         if (res < 0)
  98                 pgp_mpi_free(n);
  99         else
 100                 *mpi = n;
 101         return res;
 102 }
 103
 104 int
 105 pgp_mpi_write(PushFilter *dst, PGP_MPI *n)
 106 {
 107         int                     res;
 108         uint8           buf[2];
 109
 110         buf[0] = n->bits >> 8;
 111         buf[1] = n->bits & 0xFF;
 112         res = pushf_write(dst, buf, 2);
 113         if (res >= 0)
 114                 res = pushf_write(dst, n->data, n->bytes);
 115         return res;
 116 }
 117
 118 int
 119 pgp_mpi_hash(PX_MD *md, PGP_MPI *n)
 120 {
 121         uint8           buf[2];
 122
 123         buf[0] = n->bits >> 8;
 124         buf[1] = n->bits & 0xFF;
 125         px_md_update(md, buf, 2);
 126         px_md_update(md, n->data, n->bytes);
 127
 128         return 0;
 129 }
 130
 131 unsigned
 132 pgp_mpi_cksum(unsigned cksum, PGP_MPI *n)
 133 {
 134         int                     i;
 135
 136         cksum += n->bits >> 8;
 137         cksum += n->bits & 0xFF;
 138         for (i = 0; i < n->bytes; i++)
 139                 cksum += n->data[i];
 140
 141         return cksum & 0xFFFF;
 142 }