c: specify static array size in function params

The C standard states:

  A declaration of a parameter as ``array of type'' shall be adjusted to ``qualified pointer to
  type'', where the type qualifiers (if any) are those specified within the [ and ] of the
  array type derivation. If the keyword static also appears within the [ and ] of the
  array type derivation, then for each call to the function, the value of the corresponding
  actual argument shall provide access to the first element of an array with at least as many
  elements as specified by the size expression.

By changing void func(int array[4]) to void func(int array[static 4]),
we automatically get the compiler checking argument sizes for us, which
is quite nice.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 15 insertions, 15 deletions

diff --git a/src/noise.c b/src/noise.c
index fd8e7d8..c505a72 100644
--- a/src/noise.c
+++ b/src/noise.c
@@ -33,7 +33,7 @@ void noise_init(void)
 	blake2s(handshake_psk_name_hash, handshake_psk_name, NULL, NOISE_HASH_LEN, sizeof(handshake_psk_name), 0);
 }
 
-void noise_handshake_init(struct noise_handshake *handshake, struct noise_static_identity *static_identity, const u8 peer_public_key[NOISE_PUBLIC_KEY_LEN], struct wireguard_peer *peer)
+void noise_handshake_init(struct noise_handshake *handshake, struct noise_static_identity *static_identity, const u8 peer_public_key[static NOISE_PUBLIC_KEY_LEN], struct wireguard_peer *peer)
 {
 	memset(handshake, 0, sizeof(struct noise_handshake));
 	init_rwsem(&handshake->lock);
@@ -156,7 +156,7 @@ bool noise_received_with_keypair(struct noise_keypairs *keypairs, struct noise_k
 	return ret;
 }
 
-void noise_set_static_identity_private_key(struct noise_static_identity *static_identity, const u8 private_key[NOISE_PUBLIC_KEY_LEN])
+void noise_set_static_identity_private_key(struct noise_static_identity *static_identity, const u8 private_key[static NOISE_PUBLIC_KEY_LEN])
 {
 	down_write(&static_identity->lock);
 	if (private_key) {
@@ -171,7 +171,7 @@ void noise_set_static_identity_private_key(struct noise_static_identity *static_
 	up_write(&static_identity->lock);
 }
 
-void noise_set_static_identity_preshared_key(struct noise_static_identity *static_identity, const u8 preshared_key[NOISE_SYMMETRIC_KEY_LEN])
+void noise_set_static_identity_preshared_key(struct noise_static_identity *static_identity, const u8 preshared_key[static NOISE_SYMMETRIC_KEY_LEN])
 {
 	down_write(&static_identity->lock);
 	if (preshared_key) {
@@ -190,7 +190,7 @@ void noise_set_static_identity_preshared_key(struct noise_static_identity *stati
  */
 static void kdf(u8 *first_dst, u8 *second_dst, const u8 *data,
 		size_t first_len, size_t second_len, size_t data_len,
-		const u8 chaining_key[NOISE_HASH_LEN])
+		const u8 chaining_key[static NOISE_HASH_LEN])
 {
 	u8 secret[BLAKE2S_OUTBYTES];
 	u8 output[BLAKE2S_OUTBYTES + 1];
@@ -223,20 +223,20 @@ static void symmetric_key_init(struct noise_symmetric_key *key)
 	key->is_valid = true;
 }
 
-static void derive_keys(struct noise_symmetric_key *first_dst, struct noise_symmetric_key *second_dst, const u8 chaining_key[NOISE_HASH_LEN])
+static void derive_keys(struct noise_symmetric_key *first_dst, struct noise_symmetric_key *second_dst, const u8 chaining_key[static NOISE_HASH_LEN])
 {
 	kdf(first_dst->key, second_dst->key, NULL, NOISE_SYMMETRIC_KEY_LEN, NOISE_SYMMETRIC_KEY_LEN, 0, chaining_key);
 	symmetric_key_init(first_dst);
 	symmetric_key_init(second_dst);
 }
 
-static void mix_key(u8 key[NOISE_SYMMETRIC_KEY_LEN], u8 chaining_key[NOISE_HASH_LEN], const u8 *src, size_t src_len)
+static void mix_key(u8 key[static NOISE_SYMMETRIC_KEY_LEN], u8 chaining_key[static NOISE_HASH_LEN], const u8 *src, size_t src_len)
 {
 	kdf(chaining_key, key, src, NOISE_HASH_LEN, NOISE_SYMMETRIC_KEY_LEN, src_len, chaining_key);
 }
 
-static void mix_dh(u8 key[NOISE_SYMMETRIC_KEY_LEN], u8 chaining_key[NOISE_HASH_LEN],
-		   const u8 private[NOISE_PUBLIC_KEY_LEN], const u8 public[NOISE_PUBLIC_KEY_LEN])
+static void mix_dh(u8 key[static NOISE_SYMMETRIC_KEY_LEN], u8 chaining_key[static NOISE_HASH_LEN],
+		   const u8 private[static NOISE_PUBLIC_KEY_LEN], const u8 public[static NOISE_PUBLIC_KEY_LEN])
 {
 	u8 dh_calculation[NOISE_PUBLIC_KEY_LEN];
 	curve25519(dh_calculation, private, public);
@@ -244,7 +244,7 @@ static void mix_dh(u8 key[NOISE_SYMMETRIC_KEY_LEN], u8 chaining_key[NOISE_HASH_L
 	memzero_explicit(dh_calculation, NOISE_PUBLIC_KEY_LEN);
 }
 
-static void mix_hash(u8 hash[NOISE_HASH_LEN], const u8 *src, size_t src_len)
+static void mix_hash(u8 hash[static NOISE_HASH_LEN], const u8 *src, size_t src_len)
 {
 	struct blake2s_state blake;
 	blake2s_init(&blake, NOISE_HASH_LEN);
@@ -253,8 +253,8 @@ static void mix_hash(u8 hash[NOISE_HASH_LEN], const u8 *src, size_t src_len)
 	blake2s_final(&blake, hash, NOISE_HASH_LEN);
 }
 
-static void handshake_init(u8 key[NOISE_SYMMETRIC_KEY_LEN], u8 chaining_key[NOISE_HASH_LEN], u8 hash[NOISE_HASH_LEN],
-			   const u8 remote_static[NOISE_PUBLIC_KEY_LEN], const u8 psk[NOISE_SYMMETRIC_KEY_LEN])
+static void handshake_init(u8 key[static NOISE_SYMMETRIC_KEY_LEN], u8 chaining_key[static NOISE_HASH_LEN], u8 hash[static NOISE_HASH_LEN],
+			   const u8 remote_static[static NOISE_PUBLIC_KEY_LEN], const u8 psk[static NOISE_SYMMETRIC_KEY_LEN])
 {
 	memset(key, 0, NOISE_SYMMETRIC_KEY_LEN);
 	memcpy(hash, psk ? handshake_psk_name_hash : handshake_name_hash, NOISE_HASH_LEN);
@@ -269,7 +269,7 @@ static void handshake_init(u8 key[NOISE_SYMMETRIC_KEY_LEN], u8 chaining_key[NOIS
 	mix_hash(hash, remote_static, NOISE_PUBLIC_KEY_LEN);
 }
 
-static bool handshake_encrypt(u8 *dst_ciphertext, const u8 *src_plaintext, size_t src_len, u8 key[NOISE_SYMMETRIC_KEY_LEN], u8 hash[NOISE_HASH_LEN])
+static bool handshake_encrypt(u8 *dst_ciphertext, const u8 *src_plaintext, size_t src_len, u8 key[static NOISE_SYMMETRIC_KEY_LEN], u8 hash[static NOISE_HASH_LEN])
 {
 	if (!chacha20poly1305_encrypt(dst_ciphertext, src_plaintext, src_len, hash, NOISE_HASH_LEN, 0 /* Always zero for Noise_IK */, key))
 		return false;
@@ -277,7 +277,7 @@ static bool handshake_encrypt(u8 *dst_ciphertext, const u8 *src_plaintext, size_
 	return true;
 }
 
-static bool handshake_decrypt(u8 *dst_plaintext, const u8 *src_ciphertext, size_t src_len, u8 key[NOISE_SYMMETRIC_KEY_LEN], u8 hash[NOISE_HASH_LEN])
+static bool handshake_decrypt(u8 *dst_plaintext, const u8 *src_ciphertext, size_t src_len, u8 key[static NOISE_SYMMETRIC_KEY_LEN], u8 hash[static NOISE_HASH_LEN])
 {
 	if (!chacha20poly1305_decrypt(dst_plaintext, src_ciphertext, src_len, hash, NOISE_HASH_LEN, 0 /* Always zero for Noise_IK */, key))
 		return false;
@@ -285,13 +285,13 @@ static bool handshake_decrypt(u8 *dst_plaintext, const u8 *src_ciphertext, size_
 	return true;
 }
 
-static void handshake_nocrypt(u8 *dst, const u8 *src, size_t src_len, u8 hash[NOISE_HASH_LEN])
+static void handshake_nocrypt(u8 *dst, const u8 *src, size_t src_len, u8 hash[static NOISE_HASH_LEN])
 {
 	memcpy(dst, src, src_len);
 	mix_hash(hash, src, src_len);
 }
 
-static void tai64n_now(u8 output[NOISE_TIMESTAMP_LEN])
+static void tai64n_now(u8 output[static NOISE_TIMESTAMP_LEN])
 {
 	struct timeval now;
 	do_gettimeofday(&now);