wiphy: add _generate_address_from_ssid

This API is being added to support per-network MAC address
generation. The MAC is generated based on the network SSID
and the adapters permanent address using HMAC-SHA256. The
SHA digest is then constrained to make it MAC address
compliant.

Generating the MAC address like this will ensure that the
MAC remains the same each time a given SSID is connected to.
This commit is contained in:
James Prestwood 2020-03-18 11:54:17 -07:00 committed by Denis Kenzior
parent 60bb42087a
commit 1f14782857
2 changed files with 32 additions and 4 deletions

View File

@ -435,12 +435,10 @@ const uint8_t *wiphy_get_rm_enabled_capabilities(struct wiphy *wiphy)
return wiphy->rm_enabled_capabilities;
}
void wiphy_generate_random_address(struct wiphy *wiphy, uint8_t addr[static 6])
static void wiphy_address_constrain(struct wiphy *wiphy, uint8_t addr[static 6])
{
switch (mac_randomize_bytes) {
case 6:
l_getrandom(addr, 6);
/* Set the locally administered bit */
addr[0] |= 0x2;
@ -448,7 +446,6 @@ void wiphy_generate_random_address(struct wiphy *wiphy, uint8_t addr[static 6])
addr[0] &= 0xfe;
break;
case 3:
l_getrandom(addr + 3, 3);
memcpy(addr, wiphy->permanent_addr, 3);
break;
}
@ -464,6 +461,35 @@ void wiphy_generate_random_address(struct wiphy *wiphy, uint8_t addr[static 6])
addr[5] = 0x01;
}
void wiphy_generate_random_address(struct wiphy *wiphy, uint8_t addr[static 6])
{
switch (mac_randomize_bytes) {
case 6:
l_getrandom(addr, 6);
break;
case 3:
l_getrandom(addr + 3, 3);
break;
}
wiphy_address_constrain(wiphy, addr);
}
void wiphy_generate_address_from_ssid(struct wiphy *wiphy, const char *ssid,
uint8_t addr[static 6])
{
struct l_checksum *sha = l_checksum_new(L_CHECKSUM_SHA256);
l_checksum_update(sha, ssid, strlen(ssid));
l_checksum_update(sha, wiphy->permanent_addr,
sizeof(wiphy->permanent_addr));
l_checksum_get_digest(sha, addr, mac_randomize_bytes);
l_checksum_free(sha);
wiphy_address_constrain(wiphy, addr);
}
bool wiphy_constrain_freq_set(const struct wiphy *wiphy,
struct scan_freq_set *set)
{

View File

@ -82,6 +82,8 @@ const uint8_t *wiphy_get_extended_capabilities(struct wiphy *wiphy,
const uint8_t *wiphy_get_rm_enabled_capabilities(struct wiphy *wiphy);
void wiphy_generate_random_address(struct wiphy *wiphy, uint8_t addr[static 6]);
void wiphy_generate_address_from_ssid(struct wiphy *wiphy, const char *ssid,
uint8_t addr[static 6]);
uint32_t wiphy_state_watch_add(struct wiphy *wiphy,
wiphy_state_watch_func_t func, void *user_data,