crypto: lib/chacha - add strongly-typed state zeroization

Now that the ChaCha state matrix is strongly-typed, add a helper
function chacha_zeroize_state() which zeroizes it.  Then convert all
applicable callers to use it instead of direct memzero_explicit.  No
functional changes.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 9f876ed2655b..5f22a08101f6 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -422,7 +422,7 @@ static void _get_random_bytes(void *buf, size_t len)
 		buf += CHACHA_BLOCK_SIZE;
 	}
 
-	memzero_explicit(&chacha_state, sizeof(chacha_state));
+	chacha_zeroize_state(&chacha_state);
 }
 
 /*
@@ -485,7 +485,7 @@ static ssize_t get_random_bytes_user(struct iov_iter *iter)
 
 	memzero_explicit(block, sizeof(block));
 out_zero_chacha:
-	memzero_explicit(&chacha_state, sizeof(chacha_state));
+	chacha_zeroize_state(&chacha_state);
 	return ret ? ret : -EFAULT;
 }