@okxweb3/crypto-lib/dist/elliptic/ec/signature.js

A base package for @okxweb3/coin-*

'use strict';
var BN = require('bn.js/lib/bn');
var utils = require('../utils');
var assert = utils.assert;
function Signature(curve, options, enc) {
    if (options instanceof Signature)
        return options;
    if (this._importDER(options, enc))
        return;
    assert(options.r && options.s, 'Signature without r or s');
    this.r = new BN(options.r, 16);
    this.s = new BN(options.s, 16);
    if (options.recoveryParam === undefined)
        this.recoveryParam = null;
    else
        this.recoveryParam = options.recoveryParam;
    this.curve = curve;
    this.byteLength = this.curve.n.byteLength();
}
module.exports = Signature;
function Position() {
    this.place = 0;
}
function getLength(buf, p) {
    var initial = buf[p.place++];
    if (!(initial & 0x80)) {
        return initial;
    }
    var octetLen = initial & 0xf;
    if (octetLen === 0 || octetLen > 4) {
        return false;
    }
    if (buf[p.place] === 0x00) {
        return false;
    }
    var val = 0;
    for (var i = 0, off = p.place; i < octetLen; i++, off++) {
        val <<= 8;
        val |= buf[off];
        val >>>= 0;
    }
    if (val <= 0x7f) {
        return false;
    }
    p.place = off;
    return val;
}
function rmPadding(buf) {
    var i = 0;
    var len = buf.length - 1;
    while (!buf[i] && !(buf[i + 1] & 0x80) && i < len) {
        i++;
    }
    if (i === 0) {
        return buf;
    }
    return buf.slice(i);
}
Signature.prototype._importDER = function _importDER(data, enc) {
    data = utils.toArray(data, enc);
    var p = new Position();
    if (data[p.place++] !== 0x30) {
        return false;
    }
    var len = getLength(data, p);
    if (len === false) {
        return false;
    }
    if ((len + p.place) !== data.length) {
        return false;
    }
    if (data[p.place++] !== 0x02) {
        return false;
    }
    var rlen = getLength(data, p);
    if (rlen === false) {
        return false;
    }
    if ((data[p.place] & 128) !== 0) {
        return false;
    }
    var r = data.slice(p.place, rlen + p.place);
    p.place += rlen;
    if (data[p.place++] !== 0x02) {
        return false;
    }
    var slen = getLength(data, p);
    if (slen === false) {
        return false;
    }
    if (data.length !== slen + p.place) {
        return false;
    }
    if ((data[p.place] & 128) !== 0) {
        return false;
    }
    var s = data.slice(p.place, slen + p.place);
    if (r[0] === 0) {
        if (r[1] & 0x80) {
            r = r.slice(1);
        }
        else {
            return false;
        }
    }
    if (s[0] === 0) {
        if (s[1] & 0x80) {
            s = s.slice(1);
        }
        else {
            return false;
        }
    }
    this.r = new BN(r);
    this.s = new BN(s);
    this.recoveryParam = null;
    return true;
};
function constructLength(arr, len) {
    if (len < 0x80) {
        arr.push(len);
        return;
    }
    var octets = 1 + (Math.log(len) / Math.LN2 >>> 3);
    arr.push(octets | 0x80);
    while (--octets) {
        arr.push((len >>> (octets << 3)) & 0xff);
    }
    arr.push(len);
}
Signature.prototype.toDER = function toDER(enc) {
    var r = this.r.toArray();
    var s = this.s.toArray();
    if (r[0] & 0x80)
        r = [0].concat(r);
    if (s[0] & 0x80)
        s = [0].concat(s);
    r = rmPadding(r);
    s = rmPadding(s);
    while (!s[0] && !(s[1] & 0x80)) {
        s = s.slice(1);
    }
    var arr = [0x02];
    constructLength(arr, r.length);
    arr = arr.concat(r);
    arr.push(0x02);
    constructLength(arr, s.length);
    var backHalf = arr.concat(s);
    var res = [0x30];
    constructLength(res, backHalf.length);
    res = res.concat(backHalf);
    return utils.encode(res, enc);
};
Signature.prototype.toBytes = function toBytes() {
    const r = this.r.toArray('be', this.byteLength);
    const s = this.s.toArray('be', this.byteLength);
    return r.concat(s);
};
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