kc3-lang/gnulib/lib/md4-stream.c

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• Hash : 32a72f45
  Author :
  Date : 2023-01-01T01:14:21
  

  maint: run 'make update-copyright'
  

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• lib/md4-stream.c

• /* Functions to compute MD4 message digest of files or memory blocks.
     according to the definition of MD4 in RFC 1320 from April 1992.
     Copyright (C) 1995-1997, 1999-2003, 2005-2006, 2008-2023 Free Software
     Foundation, Inc.
  
     This file is free software: you can redistribute it and/or modify
     it under the terms of the GNU Lesser General Public License as
     published by the Free Software Foundation; either version 2.1 of the
     License, or (at your option) any later version.
  
     This file is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  
  /* Adapted by Simon Josefsson from gnulib md5.? and Libgcrypt
     cipher/md4.c . */
  
  #include <config.h>
  
  /* Specification.  */
  #include "md4.h"
  
  #include <stdlib.h>
  
  #if USE_UNLOCKED_IO
  # include "unlocked-io.h"
  #endif
  
  #define BLOCKSIZE 32768
  #if BLOCKSIZE % 64 != 0
  # error "invalid BLOCKSIZE"
  #endif
  
  /* Compute MD4 message digest for bytes read from STREAM.  The
     resulting message digest number will be written into the 16 bytes
     beginning at RESBLOCK.  */
  int
  md4_stream (FILE * stream, void *resblock)
  {
    struct md4_ctx ctx;
    size_t sum;
  
    char *buffer = malloc (BLOCKSIZE + 72);
    if (!buffer)
      return 1;
  
    /* Initialize the computation context.  */
    md4_init_ctx (&ctx);
  
    /* Iterate over full file contents.  */
    while (1)
      {
        /* We read the file in blocks of BLOCKSIZE bytes.  One call of the
           computation function processes the whole buffer so that with the
           next round of the loop another block can be read.  */
        size_t n;
        sum = 0;
  
        /* Read block.  Take care for partial reads.  */
        while (1)
          {
            n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
  
            sum += n;
  
            if (sum == BLOCKSIZE)
              break;
  
            if (n == 0)
              {
                /* Check for the error flag IFF N == 0, so that we don't
                   exit the loop after a partial read due to e.g., EAGAIN
                   or EWOULDBLOCK.  */
                if (ferror (stream))
                  {
                    free (buffer);
                    return 1;
                  }
                goto process_partial_block;
              }
  
            /* We've read at least one byte, so ignore errors.  But always
               check for EOF, since feof may be true even though N > 0.
               Otherwise, we could end up calling fread after EOF.  */
            if (feof (stream))
              goto process_partial_block;
          }
  
        /* Process buffer with BLOCKSIZE bytes.  Note that
           BLOCKSIZE % 64 == 0
         */
        md4_process_block (buffer, BLOCKSIZE, &ctx);
      }
  
  process_partial_block:;
  
    /* Process any remaining bytes.  */
    if (sum > 0)
      md4_process_bytes (buffer, sum, &ctx);
  
    /* Construct result in desired memory.  */
    md4_finish_ctx (&ctx, resblock);
    free (buffer);
    return 0;
  }
  

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