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@bitjson
Created February 10, 2020 17:58
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CashAddress Encoding, Decoding, and Error Correction in Javascript
import { instantiateSecp256k1, hexToBin, instantiateRipemd160, encodeCashAddress, CashAddressType, instantiateSha256, encodeCashAddressFormat, attemptCashAddressFormatErrorCorrection, decodeCashAddress, decodeCashAddressFormat, stringify } from 'bitcoin-ts';
(async () => {
const secp256k1 = await instantiateSecp256k1();
const sha256 = await instantiateSha256();
const ripemd160 = await instantiateRipemd160();
// Create an address from a private key
const privateKey = hexToBin('f85d4bd8a03ca106c9deb47b791803dac7f0333809e3f1dd04d182e0aba6e553');
const publicKey = secp256k1.derivePublicKeyCompressed(privateKey);
const publicKeyHash = ripemd160.hash(sha256.hash(publicKey));
// Encode a P2PKH CashAddress
const cashAddress = encodeCashAddress('bchtest', CashAddressType.P2PKH, publicKeyHash);
// Decode a CashAddress
const cashAddressDecoded = decodeCashAddress('bchtest:qq2azmyyv6dtgczexyalqar70q036yund53jvfde0x');
// Encode a P2PKH SLP Address (uses the CashAddress format)
const slpAddress = encodeCashAddressFormat('slptest', 0, publicKeyHash);
// Decode an SLP Address (uses the CashAddress format)
const slpDecoded = decodeCashAddressFormat('slptest:qq2azmyyv6dtgczexyalqar70q036yund52xtjhwam');
// Fix up to 2 errors in a CashAddress-formatted string
const broken = 'bitauth:qwtcxp42fcp06phz2xec6t5krau0ftewxefy50j9xyfxwa38df40zp5xz6t5w';
const result = attemptCashAddressFormatErrorCorrection(broken);
// Example prompt to correct a Bitauth ID
const pointToCorrections = (c: number[]) => Array.from({ length: c[c.length - 1] + 1 }, (_, i) => c.includes(i) ? '^' : '-').join('');
console.log('Cash Address:');
console.log(cashAddress);
console.log(stringify(cashAddressDecoded), '\n');
console.log('SLP Address:');
console.log(slpAddress);
console.log(stringify(slpDecoded), '\n');
console.log('Error Correction:');
console.log(result);
console.log(typeof result === 'string' ? '[no correction]' : `
You entered: ${broken}
${pointToCorrections(result.corrections)}
Did you mean: ${result.address}?`);
})();
Cash Address:
bchtest:qq2azmyyv6dtgczexyalqar70q036yund53jvfde0x
{
"hash": "<Uint8Array: 0x15d16c84669ab46059313bf0747e781f1d13936d>",
"prefix": "bchtest",
"type": 0
}
SLP Address:
slptest:qq2azmyyv6dtgczexyalqar70q036yund52xtjhwam
{
"hash": "<Uint8Array: 0x15d16c84669ab46059313bf0747e781f1d13936d>",
"prefix": "slptest",
"version": 0
}
Error Correction:
{
address: 'bitauth:qwtcxp42fcp06phz2xec6t5krau0ftew5efy50j9xyfxwa38df40zp58z6t5w',
corrections: [ 40, 63 ]
}
You entered: bitauth:qwtcxp42fcp06phz2xec6t5krau0ftewxefy50j9xyfxwa38df40zp5xz6t5w
----------------------------------------^----------------------^
Did you mean: bitauth:qwtcxp42fcp06phz2xec6t5krau0ftew5efy50j9xyfxwa38df40zp58z6t5w?
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