first commit

clientsdk/ccdata/ccdecode.go

@@ -0,0 +1,62 @@
+package ccdata
+
+// GetSecValueFinalIndexByValue GetSecValueFinalIndexByValue
+func GetSecValueFinalIndexByValue(data []byte, value byte) byte {
+	tmpLen := len(data)
+	for index := 0; index < tmpLen; index++ {
+		if data[index] == value {
+			return byte(index)
+		}
+	}
+	return byte(0)
+}
+
+// DecodeSecValueFinal DecodeSecValueFinal
+func DecodeSecValueFinal(encryptRecordData []byte, saeTableFinal []byte) []byte {
+	for index := 0; index < 4; index++ {
+		for secIndex := 0; secIndex < 4; secIndex++ {
+			recordIndex := index*4 + secIndex
+			tmpOffset := index*0x400 + secIndex*0x100
+			tmpIndex := GetSecValueFinalIndexByValue(saeTableFinal[tmpOffset:tmpOffset+256], encryptRecordData[recordIndex])
+			encryptRecordData[recordIndex] = tmpIndex
+		}
+	}
+
+	return encryptRecordData
+}
+
+// DecodeCircleShift DecodeCircleShift
+func DecodeCircleShift(data []byte, offset uint32, pos uint32) []byte {
+	retData := []byte{}
+	retData = append(retData, data[0:]...)
+	if pos == 1 {
+		retData[offset+1] = data[offset+0]
+		retData[offset+2] = data[offset+1]
+		retData[offset+3] = data[offset+2]
+		retData[offset+0] = data[offset+3]
+	}
+
+	if pos == 2 {
+		retData[offset+2] = data[offset+0]
+		retData[offset+0] = data[offset+2]
+		retData[offset+2] = data[offset+1]
+		retData[offset+1] = data[offset+3]
+	}
+
+	if pos == 3 {
+		retData[offset+3] = data[offset+0]
+		retData[offset+0] = data[offset+1]
+		retData[offset+1] = data[offset+2]
+		retData[offset+2] = data[offset+3]
+	}
+
+	return retData
+}
+
+// DecodeShiftRows DecodeShiftRows
+func DecodeShiftRows(data []byte) []byte {
+	retData := DecodeCircleShift(data, 4, 1)
+	retData = DecodeCircleShift(retData, 8, 2)
+	retData = DecodeCircleShift(retData, 12, 3)
+	return retData
+}