lib/uudecode.c

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