crypto/comp/c_zlib.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include <openssl/objects.h>
   5 #include <openssl/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(COMP_CTX *ctx, unsigned char *out,
  44              unsigned int olen, unsigned char *in, unsigned int ilen)
  45         {
  46         unsigned long l;
  47         int i;
  48         int clear=1;
  49
  50         if (ilen > 128)
  51                 {
  52                 out[0]=1;
  53                 l=olen-1;
  54                 i=compress(&(out[1]),&l,in,(unsigned long)ilen);
  55                 if (i != Z_OK)
  56                         return(-1);
  57                 if (ilen > l)
  58                         {
  59                         clear=0;
  60                         l++;
  61                         }
  62                 }
  63         if (clear)
  64                 {
  65                 out[0]=0;
  66                 memcpy(&(out[1]),in,ilen);
  67                 l=ilen+1;
  68                 }
  69 fprintf(stderr,"compress(%4d)->%4d %s\n",ilen,(int)l,(clear)?"clear":"zlib");
  70         return((int)l);
  71         }
  72
  73 static int zlib_expand_block(COMP_CTX *ctx, unsigned char *out,
  74              unsigned int olen, unsigned char *in, unsigned int ilen)
  75         {
  76         unsigned long l;
  77         int i;
  78
  79         if (in[0])
  80                 {
  81                 l=olen;
  82                 i=zz_uncompress(out,&l,&(in[1]),(unsigned long)ilen-1);
  83                 if (i != Z_OK)
  84                         return(-1);
  85                 }
  86         else
  87                 {
  88                 memcpy(out,&(in[1]),ilen-1);
  89                 l=ilen-1;
  90                 }
  91         fprintf(stderr,"expand  (%4d)->%4d %s\n",ilen,(int)l,in[0]?"zlib":"clear");
  92         return((int)l);
  93         }
  94
  95 static int zz_uncompress (Bytef *dest, uLongf *destLen, const Bytef *source,
  96              uLong sourceLen)
  97 {
  98     z_stream stream;
  99     int err;
 100
 101     stream.next_in = (Bytef*)source;
 102     stream.avail_in = (uInt)sourceLen;
 103     /* Check for source > 64K on 16-bit machine: */
 104     if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
 105
 106     stream.next_out = dest;
 107     stream.avail_out = (uInt)*destLen;
 108     if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
 109
 110     stream.zalloc = (alloc_func)0;
 111     stream.zfree = (free_func)0;
 112
 113     err = inflateInit(&stream);
 114     if (err != Z_OK) return err;
 115
 116     err = inflate(&stream, Z_FINISH);
 117     if (err != Z_STREAM_END) {
 118         inflateEnd(&stream);
 119         return err;
 120     }
 121     *destLen = stream.total_out;
 122
 123     err = inflateEnd(&stream);
 124     return err;
 125 }
 126
 127 #endif
 128
 129 COMP_METHOD *COMP_zlib(void)
 130         {
 131         return(&zlib_method);
 132         }
 133