feat(mldsa): add mldsa

mldsa/internal/byteorder/byteorder.go

@@ -0,0 +1,7 @@
+package byteorder
+
+import "encoding/binary"
+
+func LEPutUint16(b []byte, v uint16) {
+	binary.LittleEndian.PutUint16(b, v)
+}

mldsa/internal/constanttime/constant_time.go

@@ -0,0 +1,25 @@
+package constanttime
+
+import "crypto/subtle"
+
+// Select returns x if v == 1 and y if v == 0.
+// Its behavior is undefined if v takes any other value.
+func Select(v, x, y int) int {
+	return subtle.ConstantTimeSelect(v, x, y)
+}
+
+// ByteEq returns 1 if x == y and 0 otherwise.
+func ByteEq(x, y uint8) int {
+	return subtle.ConstantTimeByteEq(x, y)
+}
+
+// Eq returns 1 if x == y and 0 otherwise.
+func Eq(x, y int32) int {
+	return subtle.ConstantTimeEq(x, y)
+}
+
+// LessOrEq returns 1 if x <= y and 0 otherwise.
+// Its behavior is undefined if x or y are negative or > 2**31 - 1.
+func LessOrEq(x, y int) int {
+	return subtle.ConstantTimeLessOrEq(x, y)
+}

mldsa/internal/cryptotest/stubs.go

@@ -0,0 +1,5 @@
+package cryptotest
+
+import "testing"
+
+func SkipTestAllocations(t *testing.T) {}