crypto/comp/c_zlib.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "objects.h"
   5 #include "comp.h"
   6
   7 COMP_METHOD *COMP_zlib(void );
   8
   9 #ifndef ZLIB
  10
  11 static COMP_METHOD zlib_method={
  12         NID_undef,
  13         "(null)",
  14         NULL,
  15         NULL,
  16         NULL,
  17         NULL,
  18         NULL,
  19         };
  20
  21 #else
  22
  23 #include <zlib.h>
  24
  25 static int zlib_compress_block(COMP_CTX *ctx, unsigned char *out,
  26         unsigned int olen, unsigned char *in, unsigned int ilen);
  27 static int zlib_expand_block(COMP_CTX *ctx, unsigned char *out,
  28         unsigned int olen, unsigned char *in, unsigned int ilen);
  29
  30 static int zz_uncompress(Bytef *dest, uLongf *destLen, const Bytef *source,
  31         uLong sourceLen);
  32
  33 static COMP_METHOD zlib_method={
  34         NID_zlib_compression,
  35         LN_zlib_compression,
  36         NULL,
  37         NULL,
  38         zlib_compress_block,
  39         zlib_expand_block,
  40         NULL,
  41         };
  42
  43 static int zlib_compress_block(ctx,out,olen,in,ilen)
  44 COMP_CTX *ctx;
  45 unsigned char *out;
  46 unsigned int olen;
  47 unsigned char *in;
  48 unsigned int ilen;
  49         {
  50         unsigned long l;
  51         int i;
  52         int clear=1;
  53
  54         if (ilen > 128)
  55                 {
  56                 out[0]=1;
  57                 l=olen-1;
  58                 i=compress(&(out[1]),&l,in,(unsigned long)ilen);
  59                 if (i != Z_OK)
  60                         return(-1);
  61                 if (ilen > l)
  62                         {
  63                         clear=0;
  64                         l++;
  65                         }
  66                 }
  67         if (clear)
  68                 {
  69                 out[0]=0;
  70                 memcpy(&(out[1]),in,ilen);
  71                 l=ilen+1;
  72                 }
  73 fprintf(stderr,"compress(%4d)->%4d %s\n",ilen,(int)l,(clear)?"clear":"zlib");
  74         return((int)l);
  75         }
  76
  77 static int zlib_expand_block(ctx,out,olen,in,ilen)
  78 COMP_CTX *ctx;
  79 unsigned char *out;
  80 unsigned int olen;
  81 unsigned char *in;
  82 unsigned int ilen;
  83         {
  84         unsigned long l;
  85         int i;
  86
  87         if (in[0])
  88                 {
  89                 l=olen;
  90                 i=zz_uncompress(out,&l,&(in[1]),(unsigned long)ilen-1);
  91                 if (i != Z_OK)
  92                         return(-1);
  93                 }
  94         else
  95                 {
  96                 memcpy(out,&(in[1]),ilen-1);
  97                 l=ilen-1;
  98                 }
  99         fprintf(stderr,"expand  (%4d)->%4d %s\n",ilen,(int)l,in[0]?"zlib":"clear");
 100         return((int)l);
 101         }
 102
 103 static int zz_uncompress (dest, destLen, source, sourceLen)
 104     Bytef *dest;
 105     uLongf *destLen;
 106     const Bytef *source;
 107     uLong sourceLen;
 108 {
 109     z_stream stream;
 110     int err;
 111
 112     stream.next_in = (Bytef*)source;
 113     stream.avail_in = (uInt)sourceLen;
 114     /* Check for source > 64K on 16-bit machine: */
 115     if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
 116
 117     stream.next_out = dest;
 118     stream.avail_out = (uInt)*destLen;
 119     if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
 120
 121     stream.zalloc = (alloc_func)0;
 122     stream.zfree = (free_func)0;
 123
 124     err = inflateInit(&stream);
 125     if (err != Z_OK) return err;
 126
 127     err = inflate(&stream, Z_FINISH);
 128     if (err != Z_STREAM_END) {
 129         inflateEnd(&stream);
 130         return err;
 131     }
 132     *destLen = stream.total_out;
 133
 134     err = inflateEnd(&stream);
 135     return err;
 136 }
 137
 138 #endif
 139
 140 COMP_METHOD *COMP_zlib()
 141         {
 142         return(&zlib_method);
 143         }
 144