hex.c

   1 #include "cache.h"
   2
   3 const signed char hexval_table[256] = {
   4          -1, -1, -1, -1, -1, -1, -1, -1,                /* 00-07 */
   5          -1, -1, -1, -1, -1, -1, -1, -1,                /* 08-0f */
   6          -1, -1, -1, -1, -1, -1, -1, -1,                /* 10-17 */
   7          -1, -1, -1, -1, -1, -1, -1, -1,                /* 18-1f */
   8          -1, -1, -1, -1, -1, -1, -1, -1,                /* 20-27 */
   9          -1, -1, -1, -1, -1, -1, -1, -1,                /* 28-2f */
  10           0,  1,  2,  3,  4,  5,  6,  7,                /* 30-37 */
  11           8,  9, -1, -1, -1, -1, -1, -1,                /* 38-3f */
  12          -1, 10, 11, 12, 13, 14, 15, -1,                /* 40-47 */
  13          -1, -1, -1, -1, -1, -1, -1, -1,                /* 48-4f */
  14          -1, -1, -1, -1, -1, -1, -1, -1,                /* 50-57 */
  15          -1, -1, -1, -1, -1, -1, -1, -1,                /* 58-5f */
  16          -1, 10, 11, 12, 13, 14, 15, -1,                /* 60-67 */
  17          -1, -1, -1, -1, -1, -1, -1, -1,                /* 68-67 */
  18          -1, -1, -1, -1, -1, -1, -1, -1,                /* 70-77 */
  19          -1, -1, -1, -1, -1, -1, -1, -1,                /* 78-7f */
  20          -1, -1, -1, -1, -1, -1, -1, -1,                /* 80-87 */
  21          -1, -1, -1, -1, -1, -1, -1, -1,                /* 88-8f */
  22          -1, -1, -1, -1, -1, -1, -1, -1,                /* 90-97 */
  23          -1, -1, -1, -1, -1, -1, -1, -1,                /* 98-9f */
  24          -1, -1, -1, -1, -1, -1, -1, -1,                /* a0-a7 */
  25          -1, -1, -1, -1, -1, -1, -1, -1,                /* a8-af */
  26          -1, -1, -1, -1, -1, -1, -1, -1,                /* b0-b7 */
  27          -1, -1, -1, -1, -1, -1, -1, -1,                /* b8-bf */
  28          -1, -1, -1, -1, -1, -1, -1, -1,                /* c0-c7 */
  29          -1, -1, -1, -1, -1, -1, -1, -1,                /* c8-cf */
  30          -1, -1, -1, -1, -1, -1, -1, -1,                /* d0-d7 */
  31          -1, -1, -1, -1, -1, -1, -1, -1,                /* d8-df */
  32          -1, -1, -1, -1, -1, -1, -1, -1,                /* e0-e7 */
  33          -1, -1, -1, -1, -1, -1, -1, -1,                /* e8-ef */
  34          -1, -1, -1, -1, -1, -1, -1, -1,                /* f0-f7 */
  35          -1, -1, -1, -1, -1, -1, -1, -1,                /* f8-ff */
  36 };
  37
  38 int get_sha1_hex(const char *hex, unsigned char *sha1)
  39 {
  40         int i;
  41         for (i = 0; i < 20; i++) {
  42                 unsigned int val;
  43                 /*
  44                  * hex[1]=='\0' is caught when val is checked below,
  45                  * but if hex[0] is NUL we have to avoid reading
  46                  * past the end of the string:
  47                  */
  48                 if (!hex[0])
  49                         return -1;
  50                 val = (hexval(hex[0]) << 4) | hexval(hex[1]);
  51                 if (val & ~0xff)
  52                         return -1;
  53                 *sha1++ = val;
  54                 hex += 2;
  55         }
  56         return 0;
  57 }
  58
  59 char *sha1_to_hex(const unsigned char *sha1)
  60 {
  61         static int bufno;
  62         static char hexbuffer[4][41];
  63         static const char hex[] = "0123456789abcdef";
  64         char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
  65         int i;
  66
  67         for (i = 0; i < 20; i++) {
  68                 unsigned int val = *sha1++;
  69                 *buf++ = hex[val >> 4];
  70                 *buf++ = hex[val & 0xf];
  71         }
  72         *buf = '\0';
  73
  74         return buffer;
  75 }