sortix-mirror/libmount/uuid.c

121 lines
2.8 KiB
C

/*
* Copyright (c) 2015 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* uuid.c
* Universally unique identifier.
*/
#include <assert.h>
#include <stdbool.h>
#include <string.h>
#include <mount/uuid.h>
static bool is_hex_digit(char c)
{
return ('0' <= c && c <= '9') ||
('a' <= c && c <= 'f') ||
('A' <= c && c <= 'F');
}
static char base(unsigned char bit4)
{
return "0123456789abcdef"[bit4];
}
static unsigned char debase(char c)
{
if ( '0' <= c && c <= '9' )
return (unsigned char) (c - '0');
if ( 'a' <= c && c <= 'f' )
return (unsigned char) (c - 'a' + 10);
if ( 'A' <= c && c <= 'F' )
return (unsigned char) (c - 'A' + 10);
return 0;
}
bool uuid_validate(const char* uuid)
{
// Format: 01234567-0123-0123-0123-0123456789AB
if ( strlen(uuid) != 36 )
return false;
for ( size_t i = 0; i < 36; i++ )
{
if ( i == 8 || i == 13 || i == 18 || i == 23 )
{
if ( uuid[i] != '-' )
return false;
}
else
{
if ( !is_hex_digit(uuid[i]) )
return false;
}
}
return true;
}
void uuid_from_string(unsigned char uuid[16], const char* string)
{
size_t output_index = 0;
size_t i = 0;
while ( i < 36 )
{
assert(string[i + 0] != '\0');
if ( i == 8 || i == 13 || i == 18 || i == 23 )
{
i++;
continue;
}
uuid[output_index++] = debase(string[i + 0]) << 4 |
debase(string[i + 1]) << 0;
i += 2;
}
}
void uuid_to_string(const unsigned char uuid[16], char* string)
{
for ( size_t i = 0; i < 4; i++ )
{
*string++ = base((uuid[i] >> 4) & 0xF);
*string++ = base((uuid[i] >> 0) & 0xF);
}
*string++ = '-';
for ( size_t i = 4; i < 6; i++ )
{
*string++ = base((uuid[i] >> 4) & 0xF);
*string++ = base((uuid[i] >> 0) & 0xF);
}
*string++ = '-';
for ( size_t i = 6; i < 8; i++ )
{
*string++ = base((uuid[i] >> 4) & 0xF);
*string++ = base((uuid[i] >> 0) & 0xF);
}
*string++ = '-';
for ( size_t i = 8; i < 10; i++ )
{
*string++ = base((uuid[i] >> 4) & 0xF);
*string++ = base((uuid[i] >> 0) & 0xF);
}
*string++ = '-';
for ( size_t i = 10; i < 16; i++ )
{
*string++ = base((uuid[i] >> 4) & 0xF);
*string++ = base((uuid[i] >> 0) & 0xF);
}
*string = '\0';
}