Add dependencies/vendor (whatsapp)

vendor/go.mau.fi/libsignal/util/bytehelper/ByteHelper.go

@@ -0,0 +1,97 @@
+package bytehelper
+
+import (
+	"errors"
+)
+
+// SliceToArray will convert byte slice to a 32 byte array
+func SliceToArray(bytes []byte) [32]byte {
+	var byteArray [32]byte
+	copy(byteArray[:], bytes)
+	return byteArray
+}
+
+// SliceToArray64 will convert byte slice to a 64 byte array
+func SliceToArray64(bytes []byte) [64]byte {
+	var byteArray [64]byte
+	copy(byteArray[:], bytes)
+	return byteArray
+}
+
+// ArrayToSlice will convert a 32 byte array to byte slice
+func ArrayToSlice(bytes [32]byte) []byte {
+	return bytes[:]
+}
+
+// ArrayToSlice64 will convert a 64 byte array to byte slice
+func ArrayToSlice64(bytes [64]byte) []byte {
+	return bytes[:]
+}
+
+// Split will take the given byte array and split it into half,
+// with the first half being "firstLength" in size and the second
+// half "secondLength" in size.
+func Split(input []byte, firstLength, secondLength int) [][]byte {
+	parts := make([][]byte, 2)
+
+	parts[0] = make([]byte, firstLength)
+	copy(parts[0], input[:firstLength])
+
+	parts[1] = make([]byte, secondLength)
+	copy(parts[1], input[firstLength:])
+
+	return parts
+}
+
+// SplitThree will take the given byte array and split it into thirds,
+// with the first third being "firstLength" in size, the second third
+// being "secondLength" in size, and the last third being "thirdLength"
+// in size.
+func SplitThree(input []byte, firstLength, secondLength, thirdLength int) ([][]byte, error) {
+	if input == nil || firstLength < 0 || secondLength < 0 || thirdLength < 0 ||
+		len(input) < firstLength+secondLength+thirdLength {
+
+		return nil, errors.New("Input too small: " + string(input))
+	}
+
+	parts := make([][]byte, 3)
+
+	parts[0] = make([]byte, firstLength)
+	copy(parts[0], input[:firstLength])
+
+	parts[1] = make([]byte, secondLength)
+	copy(parts[1], input[firstLength:][:secondLength])
+
+	parts[2] = make([]byte, thirdLength)
+	copy(parts[2], input[firstLength+secondLength:])
+
+	return parts, nil
+}
+
+// Trim will trim the given byte array to the given length.
+func Trim(input []byte, length int) []byte {
+	result := make([]byte, length)
+	copy(result, input[:length])
+
+	return result
+}
+
+// Bytes5ToInt64 will convert the given byte array and offset to an int64.
+func Bytes5ToInt64(bytes []byte, offset int) int64 {
+
+	value := (int64(bytes[offset]&0xff) << 32) |
+		(int64(bytes[offset+1]&0xff) << 24) |
+		(int64(bytes[offset+2]&0xff) << 16) |
+		(int64(bytes[offset+3]&0xff) << 8) |
+		int64(bytes[offset+4]&0xff)
+
+	return value
+}
+
+// CopySlice returns a copy of the given bytes.
+func CopySlice(bytes []byte) []byte {
+	cp := make([]byte, len(bytes))
+	copy(cp, bytes)
+
+	return cp
+}