lib/uudecode.c

   1 /*
   2  * $Id$
   3  */
   4
   5 #include "squid.h"
   6 #include "uudecode.h"
   7
   8 /* aaaack but it's fast and const should make it shared text page. */
   9 const int pr2six[256] = {
  10     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  11     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 62, 64, 64, 64, 63,
  12     52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 64, 64, 64, 64, 64, 64, 64, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
  13     10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 64, 64, 64, 64, 64, 64, 26, 27,
  14     28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
  15     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  16     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  17     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  18     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  19     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
  20     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
  21 };
  22
  23 char *
  24 uudecode(const char *bufcoded)
  25 {
  26     int nbytesdecoded;
  27     const unsigned char *bufin;
  28     char *bufplain;
  29     unsigned char *bufout;
  30     int nprbytes;
  31
  32     /* Strip leading whitespace. */
  33
  34     while (*bufcoded == ' ' || *bufcoded == '\t')
  35         bufcoded++;
  36
  37     /* Figure out how many characters are in the input buffer.
  38      * Allocate this many from the per-transaction pool for the result.
  39      */
  40     bufin = (const unsigned char *) bufcoded;
  41     while (pr2six[*(bufin++)] <= 63);
  42     nprbytes = (const char *) bufin - bufcoded - 1;
  43     nbytesdecoded = ((nprbytes + 3) / 4) * 3;
  44
  45     bufplain = xmalloc(nbytesdecoded + 1);
  46     bufout = (unsigned char *) bufplain;
  47     bufin = (const unsigned char *) bufcoded;
  48
  49     while (nprbytes > 0) {
  50         *(bufout++) =
  51             (unsigned char) (pr2six[*bufin] << 2 | pr2six[bufin[1]] >> 4);
  52         *(bufout++) =
  53             (unsigned char) (pr2six[bufin[1]] << 4 | pr2six[bufin[2]] >> 2);
  54         *(bufout++) =
  55             (unsigned char) (pr2six[bufin[2]] << 6 | pr2six[bufin[3]]);
  56         bufin += 4;
  57         nprbytes -= 4;
  58     }
  59
  60     if (nprbytes & 03) {
  61         if (pr2six[bufin[-2]] > 63)
  62             nbytesdecoded -= 2;
  63         else
  64             nbytesdecoded -= 1;
  65     }
  66     bufplain[nbytesdecoded] = '\0';
  67     return bufplain;
  68 }