io.provenance.explorer.model.base.Bech32.kt Maven / Gradle / Ivy
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package io.provenance.explorer.model.base
import com.google.common.io.BaseEncoding
import java.io.ByteArrayOutputStream
/**
* Given an array of bytes, associate an HRP and return a Bech32Data instance.
*/
fun ByteArray.toBech32Data(hrp: String = Bech32.PROVENANCE_MAINNET_ACCOUNT_PREFIX) = Bech32Data(hrp, this)
/**
* Using a string in bech32 encoded address format, parses out and returns a Bech32Data instance
*/
fun String.toBech32Data() = Bech32.decode(this)
/**
* Bech32 Data encoding instance containing data for encoding as well as a human readable prefix
*/
data class Bech32Data(val hrp: String, val data: ByteArray) {
/**
* The encapsulated data returned as a Hexadecimal string
*/
val hexData = BaseEncoding.base16().encode(this.data)
/**
* Address is the Bech32 encoded value of the data prefixed with the human readable portion and
* protected by an appended checksum.
*/
val address = Bech32.encode(hrp, data)
/**
* The Bech32 Address toString prints state information for debugging purposes.
* @see address() for the bech32 encoded address string output.
*/
override fun toString(): String {
return "bech32 : ${this.address}\nhuman: ${this.hrp} \nbytes: ${this.hexData}"
/*
bech32 : provenance1gx58vp8pryh3jkvxnkvzmd0hqmqqnyqxrtvheq
human: provenance
bytes: 41A87604E1192F1959869D982DB5F706C0099006
*/
}
/** equals implementation for a Bech32Data object. */
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (javaClass != other?.javaClass) return false
other as Bech32Data
return this.hrp == other.hrp &&
this.data.contentEquals(other.data)
}
/** equals implementation for a Bech32Data object. */
override fun hashCode(): Int {
var result = hrp.hashCode()
result = 31 * result + this.data.contentHashCode()
return result
}
}
/**
* BIP173 compliant processing functions for handling Bech32 encoding for addresses
*/
class Bech32 {
companion object {
const val CHECKSUM_SIZE = 6
const val MIN_VALID_LENGTH = 8
const val MAX_VALID_LENGTH = 90
const val MIN_VALID_CODEPOINT = 33
const val MAX_VALID_CODEPOINT = 126
const val charset = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
val gen = intArrayOf(0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3)
// Mainnet account prefixes
const val PROVENANCE_MAINNET_PREFIX = "pb"
const val PROVENANCE_MAINNET_ACCOUNT_PREFIX = PROVENANCE_MAINNET_PREFIX
const val PROVENANCE_MAINNET_VALIDATOR_ACCOUNT_PREFIX = PROVENANCE_MAINNET_PREFIX + "valoper"
const val PROVENANCE_MAINNET_CONSENSUS_ACCOUNT_PREFIX = PROVENANCE_MAINNET_PREFIX + "valcons"
// Test net account prefixes are broken out separately so keys/accounts used for test can be easily identified
const val PROVENANCE_TESTNET_PREFIX = "tp"
const val PROVENANCE_TESTNET_ACCOUNT_PREFIX = PROVENANCE_TESTNET_PREFIX
const val PROVENANCE_TESTNET_VALIDATOR_ACCOUNT_PREFIX = PROVENANCE_TESTNET_PREFIX + "valoper"
const val PROVENANCE_TESTNET_CONSENSUS_ACCOUNT_PREFIX = PROVENANCE_TESTNET_PREFIX + "valcons"
// NFT (Scope) prefixes
const val SCOPE_PREFIX = "scope"
const val SESSION_PREFIX = "session"
const val RECORD_PREFIX = "record"
const val SCOPE_SPEC_PREFIX = "scopespec"
const val CONTRACT_SPEC_PREFIX = "contractspec"
const val RECORD_SPEC_PREFIX = "recspec"
/** Decodes a Bech32 String */
fun decode(bech32: String): Bech32Data {
require(bech32.length in MIN_VALID_LENGTH..MAX_VALID_LENGTH) { "invalid bech32 string length" }
require(bech32.toCharArray().none { c -> c.code < MIN_VALID_CODEPOINT || c.code > MAX_VALID_CODEPOINT }) {
"invalid character in bech32: ${bech32.toCharArray().map { c -> c.code }
.filter { c -> c < MIN_VALID_CODEPOINT || c > MAX_VALID_CODEPOINT }}"
}
require(bech32 == bech32.lowercase() || bech32 == bech32.uppercase()) {
"bech32 must be either all upper or lower case"
}
require(bech32.substring(1).dropLast(CHECKSUM_SIZE).contains('1')) { "invalid index of '1'" }
val hrp = bech32.substringBeforeLast('1').lowercase()
val dataString = bech32.substringAfterLast('1').lowercase()
require(dataString.toCharArray().all { c -> charset.contains(c) }) { "invalid data encoding character in bech32" }
val dataBytes = dataString.map { c -> charset.indexOf(c).toByte() }.toByteArray()
val checkBytes = dataString.takeLast(CHECKSUM_SIZE).map { c -> charset.indexOf(c).toByte() }.toByteArray()
val actualSum = checksum(hrp, dataBytes.dropLast(CHECKSUM_SIZE).toTypedArray())
require(1 == polymod(expandHrp(hrp).plus(dataBytes.map { d -> d.toInt() }))) { "checksum failed: $checkBytes != $actualSum" }
return Bech32Data(hrp, convertBits(dataBytes.dropLast(CHECKSUM_SIZE).toByteArray(), 5, 8, false))
}
/**
* Encodes the provided hrp and data to a Bech32 address string.
* @param hrp the human readable portion (prefix) to use.
* @param eightBitData an array of 8-bit encoded bytes.
*/
fun encode(hrp: String, eightBitData: ByteArray) =
encodeFiveBitData(hrp, convertBits(eightBitData, 8, 5, true))
/** Encodes 5-bit bytes (fiveBitData) with a given human readable portion (hrp) into a bech32 string. */
private fun encodeFiveBitData(hrp: String, fiveBitData: ByteArray): String {
return (
fiveBitData.plus(checksum(hrp, fiveBitData.toTypedArray()))
.map { b -> charset[b.toInt()] }
).joinToString("", hrp + "1")
}
/**
* ConvertBits regroups bytes with toBits set based on reading groups of bits as a continuous stream group by fromBits.
* This process is used to convert from base64 (from 8) to base32 (to 5) or the inverse.
*/
private fun convertBits(data: ByteArray, fromBits: Int, toBits: Int, pad: Boolean): ByteArray {
require(fromBits in 1..8 && toBits in 1..8) { "only bit groups between 1 and 8 are supported" }
var acc = 0
var bits = 0
val out = ByteArrayOutputStream(64)
val maxv = (1 shl toBits) - 1
val maxAcc = (1 shl (fromBits + toBits - 1)) - 1
for (b in data) {
val value = b.toInt() and 0xff
if ((value ushr fromBits) != 0) {
throw IllegalArgumentException(String.format("Input value '%X' exceeds '%d' bit size", value, fromBits))
}
acc = ((acc shl fromBits) or value) and maxAcc
bits += fromBits
while (bits >= toBits) {
bits -= toBits
out.write((acc ushr bits) and maxv)
}
}
if (pad) {
if (bits > 0) {
out.write((acc shl (toBits - bits)) and maxv)
}
} else if (bits >= fromBits || ((acc shl (toBits - bits)) and maxv) != 0) {
throw IllegalArgumentException("Could not convert bits, invalid padding")
}
return out.toByteArray()
}
/** Calculates a bech32 checksum based on BIP 173 specification */
private fun checksum(hrp: String, data: Array): ByteArray {
val values = expandHrp(hrp)
.plus(data.map { d -> d.toInt() })
.plus(Array(6) { 0 }.toIntArray())
val poly = polymod(values) xor 1
return (0..5).map {
((poly shr (5 * (5 - it))) and 31).toByte()
}.toByteArray()
}
/** Expands the human readable prefix per BIP173 for Checksum encoding */
private fun expandHrp(hrp: String) =
hrp.map { c -> c.code shr 5 }
.plus(0)
.plus(hrp.map { c -> c.code and 31 })
.toIntArray()
/** Polynomial division function for checksum calculation. For details see BIP173 */
private fun polymod(values: IntArray): Int {
var chk = 1
return values.map { v ->
val b = chk shr 25
chk = ((chk and 0x1ffffff) shl 5) xor v
(0..4).map {
if (((b shr it) and 1) == 1) {
chk = chk xor gen[it]
}
}
}.let { chk }
}
}
}