7f348ca0bd
...no longer relies on Manuel's repo hostig a version of "bignum" that actually
contained bignumber.js. This moves bignumber.js internally and removes bignum
from the browser build process. Also adds a bitcore.Bignum that links to the
right thing. In node, browser.Bignum is require('bignum'). And in the browser,
bitcore.Bignum is is now Bignumber.js (same as before ... except bignumber.js
is now inside bitcore).
117 lines
2.7 KiB
JavaScript
117 lines
2.7 KiB
JavaScript
var crypto = require('crypto');
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var bignum = require('./Bignum');
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var globalBuffer = new Buffer(1024);
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var zerobuf = new Buffer(0);
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var ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';
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var ALPHABET_ZERO = ALPHABET[0];
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var ALPHABET_BUF = new Buffer(ALPHABET, 'ascii');
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var ALPHABET_INV = {};
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for(var i=0; i < ALPHABET.length; i++) {
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ALPHABET_INV[ALPHABET[i]] = i;
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};
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// Vanilla Base58 Encoding
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var base58 = {
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encode: function(buf) {
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var str;
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var x = bignum.fromBuffer(buf);
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var r;
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if(buf.length < 512) {
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str = globalBuffer;
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} else {
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str = new Buffer(buf.length << 1);
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}
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var i = str.length - 1;
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while(x.gt(0)) {
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r = x.mod(58);
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x = x.div(58);
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str[i] = ALPHABET_BUF[r.toNumber()];
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i--;
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}
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// deal with leading zeros
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var j=0;
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while(buf[j] == 0) {
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str[i] = ALPHABET_BUF[0];
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j++; i--;
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}
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return str.slice(i+1,str.length).toString('ascii');
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},
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decode: function(str) {
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if(str.length == 0) return zerobuf;
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var answer = bignum(0);
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for(var i=0; i<str.length; i++) {
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answer.mul(58)
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answer = answer.mul(58);
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answer = answer.add(ALPHABET_INV[str[i]]);
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};
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var i = 0;
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while(i < str.length && str[i] == ALPHABET_ZERO) {
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i++;
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}
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if(i > 0) {
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var zb = new Buffer(i);
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zb.fill(0);
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if(i == str.length) return zb;
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answer = answer.toBuffer();
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return Buffer.concat([zb, answer], i+answer.length);
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} else {
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return answer.toBuffer();
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}
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},
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};
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// Base58Check Encoding
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function sha256(data) {
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return new Buffer(crypto.createHash('sha256').update(data).digest('binary'), 'binary');
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};
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function doubleSHA256(data) {
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return sha256(sha256(data));
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};
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var base58Check = {
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encode: function(buf) {
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var checkedBuf = new Buffer(buf.length + 4);
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var hash = doubleSHA256(buf);
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buf.copy(checkedBuf);
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hash.copy(checkedBuf, buf.length);
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return base58.encode(checkedBuf);
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},
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decode: function(s) {
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var buf = base58.decode(s);
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if (buf.length < 4) {
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throw new Error("invalid input: too short");
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}
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var data = buf.slice(0, -4);
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var csum = buf.slice(-4);
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var hash = doubleSHA256(data);
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var hash4 = hash.slice(0, 4);
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if (csum.toString() != hash4.toString()) {
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throw new Error("checksum mismatch");
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}
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return data;
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},
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};
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// if you frequently do base58 encodings with data larger
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// than 512 bytes, you can use this method to expand the
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// size of the reusable buffer
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exports.setBuffer = function(buf) {
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globalBuffer = buf;
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};
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exports.base58 = base58;
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exports.base58Check = base58Check;
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exports.encode = base58.encode;
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exports.decode = base58.decode;
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