[PATCH] crypto: Clear secrets from stack in hmac_sha256_vector()

[Andrei Otcheretianski]

k_pad and tk were not cleared. Fix it.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski at intel.com>
---
 src/crypto/sha256.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/crypto/sha256.c b/src/crypto/sha256.c
index 17af964ad0..166ca9b2f8 100644
--- a/src/crypto/sha256.c
+++ b/src/crypto/sha256.c
@@ -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) {
 		/*
@@ -84,7 +85,13 @@ 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);
+
+	forced_memzero(k_pad, sizeof(k_pad));
+	forced_memzero(tk, sizeof(tk));
+
+	return ret;
 }
 
 
-- 
2.25.1