utils/wvhex.cc

   1 /*
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 1997-2002 Net Integration Technologies, Inc.
   4  *
   5  * Hex encoder and decoder.
   6  */
   7 #include "wvhex.h"
   8 #include <ctype.h>
   9
  10
  11 static inline char tohex(int digit, char alphabase)
  12 {
  13     return (digit < 10 ? '0' : alphabase) + digit;
  14 }
  15
  16 static inline int fromhex(char digit)
  17 {
  18     if (isdigit(digit))
  19         return digit - '0';
  20     if (isupper(digit))
  21         return digit - 'A' + 10;
  22     return digit - 'a' + 10;
  23 }
  24
  25 /***** WvHexEncoder *****/
  26
  27 WvHexEncoder::WvHexEncoder(bool use_uppercase)
  28 {
  29     alphabase = (use_uppercase ? 'A' : 'a') - 10;
  30     _reset();
  31 }
  32
  33
  34 bool WvHexEncoder::_reset()
  35 {
  36     return true;
  37 }
  38
  39
  40 bool WvHexEncoder::_encode(WvBuf &in, WvBuf &out, bool flush)
  41 {
  42     while (in.used() != 0)
  43     {
  44         unsigned char byte = in.getch();
  45         out.putch(tohex(byte >> 4, alphabase));
  46         out.putch(tohex(byte & 15, alphabase));
  47     }
  48     return true;
  49 }
  50
  51
  52 /***** WvHexDecoder *****/
  53
  54 WvHexDecoder::WvHexDecoder()
  55 {
  56     _reset();
  57 }
  58
  59
  60 bool WvHexDecoder::_reset()
  61 {
  62     issecond = false;
  63     first = 0;
  64     return true;
  65 }
  66
  67
  68 bool WvHexDecoder::_encode(WvBuf &in, WvBuf &out, bool flush)
  69 {
  70     while (in.used() != 0)
  71     {
  72         char ch = (char) in.getch();
  73         if (isxdigit(ch))
  74         {
  75             int digit = fromhex(ch);
  76             if ( (issecond = ! issecond) )
  77                 first = digit;
  78             else
  79                 out.putch(first << 4 | digit);
  80             continue;
  81         }
  82         if (isspace(ch))
  83             continue;
  84         seterror("invalid character '%s' in hex input", ch);
  85         return false;
  86     }
  87     if (flush && issecond)
  88         return false; // not enough hex digits supplied
  89     return true;
  90 }
  91
  92
  93 /*** Compatibility ***/
  94
  95 void hexify(char *obuf, const void *ibuf, size_t len)
  96 {
  97     size_t outlen = len * 2 + 1;
  98     WvHexEncoder(false /*use_uppercase*/).
  99         flushmemmem(ibuf, len, obuf, & outlen);
 100     obuf[outlen] = '\0';
 101 }
 102
 103
 104 void unhexify(void *obuf, const char *ibuf)
 105 {
 106     size_t inlen = strlen(ibuf);
 107     size_t outlen = inlen / 2;
 108     WvHexDecoder().flushmemmem(ibuf, inlen, obuf, & outlen);
 109 }