diff options
Diffstat (limited to 'wallet/src/main/java/net/taler/wallet/crypto/Encoding.kt')
-rw-r--r-- | wallet/src/main/java/net/taler/wallet/crypto/Encoding.kt | 134 |
1 files changed, 0 insertions, 134 deletions
diff --git a/wallet/src/main/java/net/taler/wallet/crypto/Encoding.kt b/wallet/src/main/java/net/taler/wallet/crypto/Encoding.kt deleted file mode 100644 index 25a59be..0000000 --- a/wallet/src/main/java/net/taler/wallet/crypto/Encoding.kt +++ /dev/null @@ -1,134 +0,0 @@ -/* - * This file is part of GNU Taler - * (C) 2020 Taler Systems S.A. - * - * GNU Taler is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License as published by the Free Software - * Foundation; either version 3, or (at your option) any later version. - * - * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY - * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR - * A PARTICULAR PURPOSE. See the GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License along with - * GNU Taler; see the file COPYING. If not, see <http://www.gnu.org/licenses/> - */ - -package net.taler.wallet.crypto - -import java.io.ByteArrayOutputStream - -class EncodingException : Exception("Invalid encoding") - - -object Base32Crockford { - - private fun ByteArray.getIntAt(index: Int): Int { - val x = this[index].toInt() - return if (x >= 0) x else (x + 256) - } - - private var encTable = "0123456789ABCDEFGHJKMNPQRSTVWXYZ" - - fun encode(data: ByteArray): String { - val sb = StringBuilder() - val size = data.size - var bitBuf = 0 - var numBits = 0 - var pos = 0 - while (pos < size || numBits > 0) { - if (pos < size && numBits < 5) { - val d = data.getIntAt(pos++) - bitBuf = (bitBuf shl 8) or d - numBits += 8 - } - if (numBits < 5) { - // zero-padding - bitBuf = bitBuf shl (5 - numBits) - numBits = 5 - } - val v = bitBuf.ushr(numBits - 5) and 31 - sb.append(encTable[v]) - numBits -= 5 - } - return sb.toString() - } - - fun decode(encoded: String, out: ByteArrayOutputStream) { - val size = encoded.length - var bitpos = 0 - var bitbuf = 0 - var readPosition = 0 - - while (readPosition < size || bitpos > 0) { - //println("at position $readPosition with bitpos $bitpos") - if (readPosition < size) { - val v = getValue(encoded[readPosition++]) - bitbuf = (bitbuf shl 5) or v - bitpos += 5 - } - while (bitpos >= 8) { - val d = (bitbuf ushr (bitpos - 8)) and 0xFF - out.write(d) - bitpos -= 8 - } - if (readPosition == size && bitpos > 0) { - bitbuf = (bitbuf shl (8 - bitpos)) and 0xFF - bitpos = if (bitbuf == 0) 0 else 8 - } - } - } - - fun decode(encoded: String): ByteArray { - val out = ByteArrayOutputStream() - decode(encoded, out) - return out.toByteArray() - } - - private fun getValue(chr: Char): Int { - var a = chr - when (a) { - 'O', 'o' -> a = '0' - 'i', 'I', 'l', 'L' -> a = '1' - 'u', 'U' -> a = 'V' - } - if (a in '0'..'9') - return a - '0' - if (a in 'a'..'z') - a = Character.toUpperCase(a) - var dec = 0 - if (a in 'A'..'Z') { - if ('I' < a) dec++ - if ('L' < a) dec++ - if ('O' < a) dec++ - if ('U' < a) dec++ - return a - 'A' + 10 - dec - } - throw EncodingException() - } - - /** - * Compute the length of the resulting string when encoding data of the given size - * in bytes. - * - * @param dataSize size of the data to encode in bytes - * @return size of the string that would result from encoding - */ - @Suppress("unused") - fun calculateEncodedStringLength(dataSize: Int): Int { - return (dataSize * 8 + 4) / 5 - } - - /** - * Compute the length of the resulting data in bytes when decoding a (valid) string of the - * given size. - * - * @param stringSize size of the string to decode - * @return size of the resulting data in bytes - */ - @Suppress("unused") - fun calculateDecodedDataLength(stringSize: Int): Int { - return stringSize * 5 / 8 - } -} - |