@scrypt-inc/bitcoinjs-lib/dist/esm/bn.js

Client-side Bitcoin JavaScript library

import * as tools from 'uint8array-tools';
function bn2BigEndianBuf(bn) {
    let hex = bn.toString(16);
    if (hex.length % 2 !== 0) {
        hex = '0' + hex;
    }
    return Uint8Array.from(hex.match(/[\da-fA-F]{2}/g).map(h => {
        return parseInt(h, 16);
    }));
}
function bigEndianBuf2Bn(buf) {
    let ret = 0n;
    const bits = 8n;
    for (const i of buf.values()) {
        const bi = BigInt(i);
        ret = (ret << bits) + bi;
    }
    return ret;
}
function toSMBigEndian(bn) {
    let buf;
    if (bn < BigInt(0)) {
        buf = bn2BigEndianBuf(-bn);
        if (buf[0] & 0x80) {
            buf = tools.concat([Uint8Array.from([0x80]), buf]);
        }
        else {
            buf[0] = buf[0] | 0x80;
        }
    }
    else {
        buf = bn2BigEndianBuf(bn);
        if (buf[0] & 0x80) {
            buf = tools.concat([Uint8Array.from([0x00]), buf]);
        }
    }
    if (buf.length === 1 && buf[0] === 0) {
        buf = Uint8Array.from([]);
    }
    return buf;
}
export function bn2Buf(bn) {
    return toSMBigEndian(bn).reverse();
}
export function buf2BN(buf, fRequireMinimal, size) {
    const nMaxNumSize = size || 4;
    if (buf.length > nMaxNumSize) {
        throw new Error('script number overflow');
    }
    if (fRequireMinimal && buf.length > 0) {
        // Check that the number is encoded with the minimum possible
        // number of bytes.
        //
        // If the most-significant-byte - excluding the sign bit - is zero
        // then we're not minimal. Note how this test also rejects the
        // negative-zero encoding, 0x80.
        if ((buf[buf.length - 1] & 0x7f) === 0) {
            // One exception: if there's more than one byte and the most
            // significant bit of the second-most-significant-byte is set
            // it would conflict with the sign bit. An example of this case
            // is +-255, which encode to 0xff00 and 0xff80 respectively.
            // (big-endian).
            if (buf.length <= 1 || (buf[buf.length - 2] & 0x80) === 0) {
                throw new Error('non-minimally encoded script number');
            }
        }
    }
    if (buf.length === 0) {
        return BigInt(0);
    }
    buf = buf.slice().reverse();
    let ret = 0n;
    if (buf[0] & 0x80) {
        buf[0] = buf[0] & 0x7f;
        ret = bigEndianBuf2Bn(buf);
        ret = -ret;
    }
    else {
        ret = bigEndianBuf2Bn(buf);
    }
    return ret;
}