taler-android

Android apps for GNU Taler (wallet, PoS, cashier)
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ByteArrayUtils.kt (1717B)

      1 /*
      2  * This file is part of GNU Taler
      3  * (C) 2020 Taler Systems S.A.
      4  *
      5  * GNU Taler is free software; you can redistribute it and/or modify it under the
      6  * terms of the GNU General Public License as published by the Free Software
      7  * Foundation; either version 3, or (at your option) any later version.
      8  *
      9  * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
     10  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
     11  * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
     12  *
     13  * You should have received a copy of the GNU General Public License along with
     14  * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
     15  */
     16 
     17 package net.taler.common
     18 
     19 object ByteArrayUtils {
     20 
     21     private const val HEX_CHARS = "0123456789ABCDEF"
     22 
     23     fun hexStringToByteArray(data: String): ByteArray {
     24         val result = ByteArray(data.length / 2)
     25 
     26         for (i in data.indices step 2) {
     27             val firstIndex = HEX_CHARS.indexOf(data[i])
     28             val secondIndex = HEX_CHARS.indexOf(data[i + 1])
     29 
     30             val octet = firstIndex.shl(4).or(secondIndex)
     31             result[i.shr(1)] = octet.toByte()
     32         }
     33         return result
     34     }
     35 
     36 
     37     private val HEX_CHARS_ARRAY = HEX_CHARS.toCharArray()
     38 
     39     @Suppress("unused")
     40     fun toHex(byteArray: ByteArray): String {
     41         val result = StringBuffer()
     42 
     43         byteArray.forEach {
     44             val octet = it.toInt()
     45             val firstIndex = (octet and 0xF0).ushr(4)
     46             val secondIndex = octet and 0x0F
     47             result.append(HEX_CHARS_ARRAY[firstIndex])
     48             result.append(HEX_CHARS_ARRAY[secondIndex])
     49         }
     50         return result.toString()
     51     }
     52 
     53 }