DGNum/hostapd
6
0
Fork 0
Code Issues Pull requests 1 Projects Releases Packages Wiki Activity Actions

crypto: Clear secrets from stack in hmac_sha256_vector()

Browse source 
k_pad and tk were not cleared in internal HMAC-SHA256 implementation.
Clear them to avoid leaving secret material in temporary stack
variables.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
This commit is contained in:
Andrei Otcheretianski 2022-12-05 15:36:08 +02:00 • committed by Jouni Malinen
parent 909864ab1e
commit 998aeca3c8
1 changed files with 12 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
src/crypto/sha256.c
View file

@ -30,6 +30,7 @@ int hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
unsigned char tk[32];
const u8 *_addr[11];
size_t _len[11], i;
int ret;
if (num_elem > 10) {
/*
@ -70,8 +71,9 @@ int hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
_addr[i + 1] = addr[i];
_len[i + 1] = len[i];
}
if (sha256_vector(1 + num_elem, _addr, _len, mac) < 0)
return -1;
ret = sha256_vector(1 + num_elem, _addr, _len, mac);
if (ret < 0)
goto fail;
os_memset(k_pad, 0, sizeof(k_pad));
os_memcpy(k_pad, key, key_len);
@ -84,7 +86,14 @@ int hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
_len[0] = 64;
_addr[1] = mac;
_len[1] = SHA256_MAC_LEN;
return sha256_vector(2, _addr, _len, mac);
ret = sha256_vector(2, _addr, _len, mac);
fail:
forced_memzero(k_pad, sizeof(k_pad));
forced_memzero(tk, sizeof(tk));
return ret;
}