hostapd/src/utils/uuid.c
Jouni Malinen 183d3924cf WPS: Add option for using random UUID
If the uuid configuration parameter is not set, wpa_supplicant generates
an UUID automatically to allow WPS operations to proceed. This was
previously always using an UUID generated from the MAC address. This
commit adds an option to use a random UUID instead. The type of the
automatically generated UUID is set with the auto_uuid parameter: 0 =
based on MAC address (default; old behavior), 1 = random UUID.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
2017-04-13 17:38:55 +03:00

96 lines
1.8 KiB
C

/*
* Universally Unique IDentifier (UUID)
* Copyright (c) 2008, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "crypto/sha256.h"
#include "uuid.h"
int uuid_str2bin(const char *str, u8 *bin)
{
const char *pos;
u8 *opos;
pos = str;
opos = bin;
if (hexstr2bin(pos, opos, 4))
return -1;
pos += 8;
opos += 4;
if (*pos++ != '-' || hexstr2bin(pos, opos, 2))
return -1;
pos += 4;
opos += 2;
if (*pos++ != '-' || hexstr2bin(pos, opos, 2))
return -1;
pos += 4;
opos += 2;
if (*pos++ != '-' || hexstr2bin(pos, opos, 2))
return -1;
pos += 4;
opos += 2;
if (*pos++ != '-' || hexstr2bin(pos, opos, 6))
return -1;
return 0;
}
int uuid_bin2str(const u8 *bin, char *str, size_t max_len)
{
int len;
len = os_snprintf(str, max_len, "%02x%02x%02x%02x-%02x%02x-%02x%02x-"
"%02x%02x-%02x%02x%02x%02x%02x%02x",
bin[0], bin[1], bin[2], bin[3],
bin[4], bin[5], bin[6], bin[7],
bin[8], bin[9], bin[10], bin[11],
bin[12], bin[13], bin[14], bin[15]);
if (os_snprintf_error(max_len, len))
return -1;
return 0;
}
int is_nil_uuid(const u8 *uuid)
{
int i;
for (i = 0; i < UUID_LEN; i++)
if (uuid[i])
return 0;
return 1;
}
int uuid_random(u8 *uuid)
{
struct os_time t;
u8 hash[SHA256_MAC_LEN];
/* Use HMAC-SHA256 and timestamp as context to avoid exposing direct
* os_get_random() output in the UUID field. */
os_get_time(&t);
if (os_get_random(uuid, UUID_LEN) < 0 ||
hmac_sha256(uuid, UUID_LEN, (const u8 *) &t, sizeof(t), hash) < 0)
return -1;
os_memcpy(uuid, hash, UUID_LEN);
/* Version: 4 = random */
uuid[6] = (4 << 4) | (uuid[6] & 0x0f);
/* Variant specified in RFC 4122 */
uuid[8] = 0x80 | (uuid[8] & 0x3f);
return 0;
}