crypto.blake2b: use fixed arrays for block manipulations (#26751)

Author: tankf33der

vlib/crypto/blake2b/blake2b.v

@@ -49,17 +49,17 @@ const iv = [
 
 // message word schedule permutations
 const sigma = [
-	[u8(0), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15],
-	[u8(14), 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3],
-	[u8(11), 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4],
-	[u8(7), 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8],
-	[u8(9), 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13],
-	[u8(2), 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9],
-	[u8(12), 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11],
-	[u8(13), 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10],
-	[u8(6), 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5],
-	[u8(10), 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0],
-]
+	[u8(0), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]!,
+	[u8(14), 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3]!,
+	[u8(11), 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4]!,
+	[u8(7), 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8]!,
+	[u8(9), 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13]!,
+	[u8(2), 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9]!,
+	[u8(12), 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11]!,
+	[u8(13), 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10]!,
+	[u8(6), 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5]!,
+	[u8(10), 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0]!,
+]!
 
 struct Digest {
 	hash_size u8

vlib/crypto/blake2b/blake2b_block_generic.v

@@ -12,7 +12,7 @@ import math.bits
 
 // mixing function g
 @[direct_array_access; inline]
-fn g(mut v []u64, a u8, b u8, c u8, d u8, x u64, y u64) {
+fn g(mut v [16]u64, a u8, b u8, c u8, d u8, x u64, y u64) {
 	v[a] = v[a] + v[b] + x
 	v[d] = bits.rotate_left_64((v[d] ^ v[a]), nr1)
 	v[c] = v[c] + v[d]
@@ -25,7 +25,7 @@ fn g(mut v []u64, a u8, b u8, c u8, d u8, x u64, y u64) {
 
 // one complete mixing round with the function g
 @[direct_array_access; inline]
-fn (d Digest) mixing_round(mut v []u64, s []u8) {
+fn (d Digest) mixing_round(mut v [16]u64, s [16]u8) {
 	g(mut v, 0, 4, 8, 12, d.m[s[0]], d.m[s[1]])
 	g(mut v, 1, 5, 9, 13, d.m[s[2]], d.m[s[3]])
 	g(mut v, 2, 6, 10, 14, d.m[s[4]], d.m[s[5]])
@@ -41,9 +41,11 @@ fn (d Digest) mixing_round(mut v []u64, s []u8) {
 @[direct_array_access]
 fn (mut d Digest) f(f bool) {
 	// initialize the working vector
-	mut v := []u64{len: 0, cap: 16}
-	v << d.h[..8]
-	v << iv[..8]
+	mut v := [16]u64{}
+	for i in 0 .. 8 {
+		v[i] = d.h[i]
+		v[i + 8] = iv[i]
+	}
 
 	v[12] ^= d.t.lo
 	v[13] ^= d.t.hi

vlib/crypto/blake2b/blake2b_block_test.v

@@ -91,9 +91,11 @@ fn test_mixing_function_g() {
 	f := true
 
 	// initialize the working vector from the digest and IV values
-	mut v := []u64{len: 0, cap: 16}
-	v << d.h[..8]
-	v << iv[..8]
+	mut v := [16]u64{}
+	for i in 0 .. 8 {
+		v[i] = d.h[i]
+		v[i + 8] = iv[i]
+	}
 
 	// fold in the 128-bit message length
 	v[12] ^= d.t.lo