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Utility functions added

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Functions for easier Signature computation, transaction hash computation, signature verification
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tripathyr 2022-09-20 16:44:27 +05:30 committed by GitHub
parent 1c3dabed86
commit 974cf960fb
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 105 additions and 1 deletions
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106
lib_btc.js
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@ -2204,6 +2204,63 @@
buffer = buffer.concat(coinjs.numToBytes(parseInt(this.lock_time), 4));
return Crypto.util.bytesToHex(buffer);
}
//Utility funtion added to directly compute signatures without transaction index
r.transactionSigNoIndex = function(wif, sigHashType, txhash){
function serializeSig(r, s) {
var rBa = r.toByteArraySigned();
var sBa = s.toByteArraySigned();
var sequence = [];
sequence.push(0x02); // INTEGER
sequence.push(rBa.length);
sequence = sequence.concat(rBa);
sequence.push(0x02); // INTEGER
sequence.push(sBa.length);
sequence = sequence.concat(sBa);
sequence.unshift(sequence.length);
sequence.unshift(0x30); // SEQUENCE
return sequence;
}
var shType = sigHashType || 1;
var hash = Crypto.util.hexToBytes(txhash);
if(hash){
var curve = EllipticCurve.getSECCurveByName("secp256k1");
var key = coinjs.wif2privkey(wif);
var priv = BigInteger.fromByteArrayUnsigned(Crypto.util.hexToBytes(key['privkey']));
var n = curve.getN();
var e = BigInteger.fromByteArrayUnsigned(hash);
var badrs = 0
do {
var k = this.deterministicK(wif, hash, badrs);
var G = curve.getG();
var Q = G.multiply(k);
var r = Q.getX().toBigInteger().mod(n);
var s = k.modInverse(n).multiply(e.add(priv.multiply(r))).mod(n);
badrs++
} while (r.compareTo(BigInteger.ZERO) <= 0 || s.compareTo(BigInteger.ZERO) <= 0);
// Force lower s values per BIP62
var halfn = n.shiftRight(1);
if (s.compareTo(halfn) > 0) {
s = n.subtract(s);
};
var sig = serializeSig(r, s);
sig.push(parseInt(shType, 10));
return Crypto.util.bytesToHex(sig);
} else {
return false;
}
}
/* deserialize a transaction */
r.deserialize = function (buffer) {
@ -2733,7 +2790,54 @@
bytes.unshift(version)
return coinjs.bech32_encode(hrp, bytes);
}
//Five utility functions added for generating transaction hashes and verification of signatures
var changeEndianness = (string) => {
const result = [];
let len = string.length - 2;
while (len >= 0) {
result.push(string.substr(len, 2));
len -= 2;
}
return result.join('');
}
function getTransactionHash(transaction_in_hex) {
var x1,x2,x3,x4,x5;
x1 = Crypto.util.hexToBytes(transaction_in_hex);
x2 = Crypto.SHA256(x1);
x3 = Crypto.util.hexToBytes(x2);
x4 = Crypto.SHA256(x3);
x5 = changeEndianness(x4);
return x5;
}
function compressedToUncompressed(compressed) {
var t1,t2;
t1 = curve.curve.decodePointHex(compressed);
t2 = curve.curve.encodePointHex(t1);
return t2;
}
function uncompressedToCompressed(uncompressed) {
var t1,t2,t3;
t1 = uncompressed.charAt(uncompressed.length-1)
t2 = parseInt(t1,10);
//Check if the last digit is odd
if(t2 % 2 == 1) { t3 = "03";} else { t3 = "02" };
return t3+ uncompressed.substr(2,64);
}
function verifySignatureHex(hashHex,sigHex,pubHexCompressed){
var h1,s1,p1,p2;
h1 = Crypto.util.hexToBytes(hashHex);
s1 = Crypto.util.hexToBytes(sigHex);
p1 = compressedToUncompressed(pubHexCompressed);
p2 = Crypto.util.hexToBytes(p1);
return coinjs.verifySignature(h1,s1,p2);
}
btc_api.getBalance = addr => new Promise((resolve, reject) => {
fetch_api(`get_address_balance/BTC/${addr}`)
.then(result => resolve(parseFloat(result.data.confirmed_balance)))
@ -2880,4 +2984,4 @@
.catch(error => reject(error))
});
})('object' === typeof module ? module.exports : window.btc_api = {});
})('object' === typeof module ? module.exports : window.btc_api = {});