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iwd
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ie: Parse vendor specific IE 

Currently it supports Microsoft vendor specific information element
with version and type value 1 only. Typically it contains WPA security
related information.
This commit is contained in:
Ravi kumar Veeramally 2015-03-16 13:03:01 +02:00 committed by Denis Kenzior
parent 7eac75fa69
commit 50c7346d19
2 changed files with 245 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

240
src/ie.c
View File

@ -31,6 +31,7 @@
#include "ie.h"
static const uint8_t ieee_oui[3] = { 0x00, 0x0f, 0xac };
static const uint8_t microsoft_oui[3] = { 0x00, 0x50, 0xf2 };
void ie_tlv_iter_init(struct ie_tlv_iter *iter, const unsigned char *tlv,
unsigned int len)
@ -761,3 +762,242 @@ done:
return true;
}
/* 802.11i-2004, Section 7.3.2.25.1 and WPA_80211_v3_1 Section 2.1 */
static bool ie_parse_wpa_cipher_suite(const uint8_t *data,
enum ie_rsn_cipher_suite *out)
{
/*
* Compare the OUI to the ones we know. OUI Format is found in
* Figure 8-187 of 802.11
*/
if (!memcmp(data, microsoft_oui, 3)) {
/* Suite type from 802.11i-2004, Table 20da */
switch (data[3]) {
case 0:
*out = IE_RSN_CIPHER_SUITE_USE_GROUP_CIPHER;
return true;
case 1:
*out = IE_RSN_CIPHER_SUITE_WEP40;
return true;
case 2:
*out = IE_RSN_CIPHER_SUITE_TKIP;
return true;
case 4:
*out = IE_RSN_CIPHER_SUITE_CCMP;
return true;
case 5:
*out = IE_RSN_CIPHER_SUITE_WEP104;
return true;
default:
return false;
}
}
return false;
}
/* 802.11i-2004, Section 7.3.2.25.2 and WPA_80211_v3_1 Section 2.1 */
static bool ie_parse_wpa_akm_suite(const uint8_t *data,
enum ie_rsn_akm_suite *out)
{
/*
* Compare the OUI to the ones we know. OUI Format is found in
* Figure 8-187 of 802.11
*/
if (!memcmp(data, microsoft_oui, 3)) {
/* Suite type from 802.11i-2004, Table 20dc */
switch (data[3]) {
case 1:
*out = IE_RSN_AKM_SUITE_8021X;
return true;
case 2:
*out = IE_RSN_AKM_SUITE_PSK;
return true;
default:
return false;
}
}
return false;
}
static bool ie_parse_wpa_group_cipher(const uint8_t *data,
enum ie_rsn_cipher_suite *out)
{
enum ie_rsn_cipher_suite tmp;
bool r = ie_parse_wpa_cipher_suite(data, &tmp);
if (!r)
return r;
switch (tmp) {
case IE_RSN_CIPHER_SUITE_CCMP:
case IE_RSN_CIPHER_SUITE_TKIP:
case IE_RSN_CIPHER_SUITE_WEP104:
case IE_RSN_CIPHER_SUITE_WEP40:
break;
default:
return false;
}
*out = tmp;
return true;
}
static bool ie_parse_wpa_pairwise_cipher(const uint8_t *data,
enum ie_rsn_cipher_suite *out)
{
enum ie_rsn_cipher_suite tmp;
bool r = ie_parse_wpa_cipher_suite(data, &tmp);
if (!r)
return r;
switch (tmp) {
case IE_RSN_CIPHER_SUITE_CCMP:
case IE_RSN_CIPHER_SUITE_TKIP:
case IE_RSN_CIPHER_SUITE_WEP104:
case IE_RSN_CIPHER_SUITE_WEP40:
/* TODO : not sure about GROUP_CIPHER */
break;
default:
return false;
}
*out = tmp;
return true;
}
bool is_ie_wpa_ie(const uint8_t *data, uint8_t len)
{
if (!data || len < 6)
return false;
if ((!memcmp(data, microsoft_oui, 3) && data[3] == 1 &&
l_get_le16(data + 4) == 1))
return true;
return false;
}
int ie_parse_wpa(struct ie_tlv_iter *iter, struct ie_rsn_info *out_info)
{
const uint8_t *data = iter->data;
size_t len = iter->len;
struct ie_rsn_info info;
uint16_t count;
uint16_t i;
if (!is_ie_wpa_ie(iter->data, iter->len))
return -EINVAL;
info.group_cipher = IE_RSN_CIPHER_SUITE_TKIP;
info.pairwise_ciphers = IE_RSN_CIPHER_SUITE_TKIP;
info.akm_suites = IE_RSN_AKM_SUITE_PSK;
memset(&info, 0, sizeof(info));
RSNE_ADVANCE(data, len, 6);
/* Parse Group Cipher Suite field */
if (len < 4)
return -EBADMSG;
if (!ie_parse_wpa_group_cipher(data, &info.group_cipher))
return -ERANGE;
RSNE_ADVANCE(data, len, 4);
/* Parse Pairwise Cipher Suite Count field */
if (len < 2)
return -EBADMSG;
count = l_get_le16(data);
/*
* The spec doesn't seem to explicitly say what to do in this case,
* so we assume this situation is invalid.
*/
if (count == 0)
return -EINVAL;
data += 2;
len -= 2;
if (len < 4 * count)
return -EBADMSG;
/* Parse Pairwise Cipher Suite List field */
for (i = 0, info.pairwise_ciphers = 0; i < count; i++) {
enum ie_rsn_cipher_suite suite;
if (!ie_parse_wpa_pairwise_cipher(data + i * 4, &suite))
return -ERANGE;
info.pairwise_ciphers |= suite;
}
RSNE_ADVANCE(data, len, count * 4);
/* Parse AKM Suite Count field */
if (len < 2)
return -EBADMSG;
count = l_get_le16(data);
if (count == 0)
return -EINVAL;
data += 2;
len -= 2;
if (len < 4 * count)
return -EBADMSG;
/* Parse AKM Suite List field */
for (i = 0, info.akm_suites = 0; i < count; i++) {
enum ie_rsn_akm_suite suite;
if (!ie_parse_wpa_akm_suite(data + i * 4, &suite))
return -ERANGE;
info.akm_suites |= suite;
}
RSNE_ADVANCE(data, len, count * 4);
return -EBADMSG;
done:
/*
* 802.11i, Section 7.3.2.25.1
* Use of CCMP as the group cipher suite with TKIP as the
* pairwise cipher suite shall not be supported.
*/
if (info.group_cipher & IE_RSN_CIPHER_SUITE_CCMP &&
info.pairwise_ciphers & IE_RSN_CIPHER_SUITE_TKIP)
return -EBADMSG;
if (out_info)
memcpy(out_info, &info, sizeof(info));
return 0;
}
int ie_parse_wpa_from_data(const uint8_t *data, size_t len,
struct ie_rsn_info *info)
{
struct ie_tlv_iter iter;
ie_tlv_iter_init(&iter, data, len);
if (!ie_tlv_iter_next(&iter))
return -EMSGSIZE;
if (ie_tlv_iter_get_tag(&iter) != IE_TYPE_VENDOR_SPECIFIC)
return -EPROTOTYPE;
return ie_parse_wpa(&iter, info);
}

5
src/ie.h
View File

@ -264,3 +264,8 @@ int ie_parse_rsne(struct ie_tlv_iter *iter, struct ie_rsn_info *info);
int ie_parse_rsne_from_data(const uint8_t *data, size_t len,
struct ie_rsn_info *info);
bool ie_build_rsne(const struct ie_rsn_info *info, uint8_t *to);
int ie_parse_wpa(struct ie_tlv_iter *iter, struct ie_rsn_info *out_info);
int ie_parse_wpa_from_data(const uint8_t *data, size_t len,
struct ie_rsn_info *info);
bool is_ie_wpa_ie(const uint8_t *data, uint8_t len);