libctf/ctf-sha1.c

   1 /* SHA-1 thunks.
   2    Copyright (C) 2019-2021 Free Software Foundation, Inc.
   3
   4    This file is part of libctf.
   5
   6    libctf is free software; you can redistribute it and/or modify it under
   7    the terms of the GNU General Public License as published by the Free
   8    Software Foundation; either version 3, or (at your option) any later
   9    version.
  10
  11    This program is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  14    See the GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; see the file COPYING.  If not see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <ctf-impl.h>
  21 #include <ctf-sha1.h>
  22
  23 static const char hex[] = "0123456789abcdef";
  24
  25 char *
  26 ctf_sha1_fini (ctf_sha1_t *sha1, char *buf)
  27 {
  28   size_t i;
  29
  30   /* Alignment suitable for a uint32_t. */
  31   union
  32   {
  33     uint32_t align;
  34     unsigned char digest[((CTF_SHA1_SIZE - 1) / 2) + 1];
  35   } align;
  36
  37   sha1_finish_ctx (sha1, align.digest);
  38
  39   if (!buf)
  40     return NULL;
  41
  42   buf[CTF_SHA1_SIZE - 1] = '\0';
  43
  44   for (i = 0; i < (CTF_SHA1_SIZE - 1) / 2; i++)
  45     {
  46       buf[2 * i] = hex[align.digest[i] >> 4];
  47       buf[2 * i + 1] = hex[align.digest[i] & 0xf];
  48     }
  49   return buf;
  50 }