hare

commit b41a3b9cbad400925a54790f265179c36926553f
parent 266ed58ec091fa7f290d736d0b9b6605f644bdae
Author: Armin Preiml <apreiml@strohwolke.at>
Date:   Mon, 16 Jan 2023 15:56:49 +0100

crypto::chacha20: slice instead of array ptr

Slices avoid needless copying of secret data if working with buffers.
Should not break any code, since array pointers are automatically casted
to slices.

Signed-off-by: Armin Preiml <apreiml@strohwolke.at>

Diffstat:
M
crypto/chacha/+test.ha
 | 
10
+++++-----
M
crypto/chacha/chacha20.ha
 | 
28
+++++++++++++++++-----------

2 files changed, 22 insertions(+), 16 deletions(-)
diff --git a/crypto/chacha/+test.ha b/crypto/chacha/+test.ha
@@ -53,7 +53,7 @@ use io;
 	let c = chacha20();
 	defer io::close(&c)!;
 
-	chacha20_init(&c, &cipherbuf, &key, &nonce);
+	chacha20_init(&c, &cipherbuf, key, nonce);
 	setctr(&c, 1);
 
 	const n = io::writeall(&c, msg)!;
@@ -63,7 +63,7 @@ use io;
 	result = [0...];
 	cipherbuf = bufio::fixed(result, io::mode::WRITE);
 
-	chacha20_init(&c, &cipherbuf, &key, &nonce);
+	chacha20_init(&c, &cipherbuf, key, nonce);
 	setctr(&c, 1);
 	io::write(&c, msg[..10])!;
 	io::write(&c, msg[10..63])!;
@@ -160,7 +160,7 @@ const xcipher: [_]u8 = [
 	let c = chacha20();
 	defer io::close(&c)!;
 
-	xchacha20_init(&c, &cipherbuf, &xkey, &xnonce);
+	xchacha20_init(&c, &cipherbuf, xkey, xnonce);
 	setctr(&c, 1);
 
 	io::writeall(&c, xmsg)!;
@@ -174,7 +174,7 @@ const xcipher: [_]u8 = [
 	let c = chacha20();
 	defer io::close(&c)!;
 
-	xchacha20_init(&c, &cipherbuf, &xkey, &xnonce);
+	xchacha20_init(&c, &cipherbuf, xkey, xnonce);
 
 	// just encrypt a few bytes of each block, to check if setctr works
 	setctr(&c, 1);
@@ -211,6 +211,6 @@ const xcipher: [_]u8 = [
 	];
 
 	let out: [32]u8 = [0...];
-	hchacha20(&out, &key, &nonce);
+	hchacha20(&out, key, nonce);
 	assert(bytes::equal(out, expected));
 };
diff --git a/crypto/chacha/chacha20.ha b/crypto/chacha/chacha20.ha
@@ -51,9 +51,12 @@ export fn chacha20() stream = {
 export fn chacha20_init(
 	s: *stream,
 	h: io::handle,
-	key: *[KEYSIZE]u8,
-	nonce: *[NONCESIZE]u8
+	key: []u8,
+	nonce: []u8
 ) void = {
+	assert(len(key) == KEYSIZE);
+	assert(len(nonce) == NONCESIZE);
+
 	s.h = h;
 
 	s.state[0] = magic[0];
@@ -77,29 +80,32 @@ export fn chacha20_init(
 export fn xchacha20_init(
 	s: *stream,
 	h: io::handle,
-	key: *[KEYSIZE]u8,
-	nonce: *[XNONCESIZE]u8
+	key: []u8,
+	nonce: []u8
 ) void = {
+	assert(len(key) == KEYSIZE);
+	assert(len(nonce) == XNONCESIZE);
+
 	let dkey: [32]u8 = [0...];
-	// XXX: https://todo.sr.ht/~sircmpwn/hare/719
-	let hnonce: [16]u8 = [0...];
-	hnonce[..] = nonce[..16];
-	hchacha20(&dkey, key, &hnonce);
+	hchacha20(&dkey, key, nonce[..16]);
 
 	let dnonce: [NONCESIZE]u8 = [0...];
 	dnonce[4..] = nonce[16..];
 
-	chacha20_init(s, h, &dkey, &dnonce);
+	chacha20_init(s, h, &dkey, dnonce);
 
 	bytes::zero(dkey);
 	bytes::zero(dnonce);
-	bytes::zero(hnonce);
 };
 
 // Derives a new key from 'key' and 'nonce' as used during XChaCha20
 // initialization. This function may only be used for specific purposes
 // such as X25519 key derivation. Do not use if in doubt.
-export fn hchacha20(out: *[32]u8, key: *[32]u8, nonce: *[16]u8) void = {
+export fn hchacha20(out: []u8, key: []u8, nonce: []u8) void = {
+	assert(len(out) == KEYSIZE);
+	assert(len(key) == KEYSIZE);
+	assert(len(nonce) == 16);
+
 	let state: [16]u32 = [0...];
 	defer bytes::zero((state: []u8: *[*]u8)[..BLOCKSIZE]);