Merge pull request #78 from tlwr/master

Base58 operations
feature-extract-files
n1474335 2017-02-13 17:50:38 +00:00 committed by GitHub
commit 701ea5890d
3 changed files with 169 additions and 0 deletions

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@ -40,6 +40,8 @@ var Categories = [
"Show Base64 offsets",
"To Base32",
"From Base32",
"To Base58",
"From Base58",
"To Base",
"From Base",
"To HTML Entity",

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@ -164,6 +164,37 @@ var OperationConfig = {
},
]
},
"From Base58": {
description: "Base58 (similar to Base64) is a notation for encoding arbitrary byte data. It improves upon Base64 by removing easily misread characters (i.e. lI0O) to improve human readability.<br><br>This operation decodes data from an ASCII string (with an alphabet of your choosing, presets included) back into its raw form.<br><br>e.g. <code>StV1DL6CwTryKyV</code> becomes <code>hello world</code><br><br>Base58 is commonly used in cryptocurrencies (Bitcoin, Ripple, etc).",
run: Base58.runFrom,
inputType: "string",
outputType: "byteArray",
args: [
{
name: "Alphabet",
type: "editableOption",
value: Base58.ALPHABET_OPTIONS
},
{
name: "Remove non&#8209;alphabet chars",
type: "boolean",
value: Base58.REMOVE_NON_ALPH_CHARS
}
]
},
"To Base58": {
description: "Base58 (similar to Base64) is a notation for encoding arbitrary byte data. It improves upon Base64 by removing easily misread characters (i.e. lI0O) to improve human readability.<br><br>This operation encodes data in an ASCII string (with an alphabet of your choosing, presets included).<br><br>e.g. <code>hello world</code> becomes <code>StV1DL6CwTryKyV</code><br><br>Base58 is commonly used in cryptocurrencies (Bitcoin, Ripple, etc).",
run: Base58.runTo,
inputType: "byteArray",
outputType: "string",
args: [
{
name: "Alphabet",
type: "editableOption",
value: Base58.ALPHABET_OPTIONS
},
]
},
"From Base32": {
description: "Base32 is a notation for encoding arbitrary byte data using a restricted set of symbols that can be conveniently used by humans and processed by computers. It uses a smaller set of characters than Base64, usually the uppercase alphabet and the numbers 2 to 7.",
run: Base64.runFrom32,

136
src/js/operations/Base58.js Executable file
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@ -0,0 +1,136 @@
/**
* Base58 operations.
*
* @author tlwr [toby@toby.codes]
* @copyright Crown Copyright 2017
* @license Apache-2.0
*
* @namespace
*/
var Base58 = {
/**
* @constant
* @default
*/
ALPHABET_OPTIONS: [
{
name: "Bitcoin",
value: "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz",
},
{
name: "Ripple",
value: "rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz",
},
],
/**
* @constant
* @default
*/
REMOVE_NON_ALPH_CHARS: true,
/**
* To Base58 operation.
*
* @param {byteArray} input
* @param {Object[]} args
* @returns {string}
*/
runTo: function(input, args) {
var alphabet = args[0] || Base58.ALPHABET_OPTIONS[0].value;
if (alphabet.length !== 58 ||
[].unique.call(alphabet).length !== 58) {
throw ("Error: alphabet must be of length 58");
}
if (input.length === 0) return "";
var result = [0];
input.forEach(function(b) {
var carry = (result[0] << 8) + b;
result[0] = carry % 58;
carry = (carry / 58) | 0;
for (var i = 1; i < result.length; i++) {
carry += result[i] << 8;
result[i] = carry % 58;
carry = (carry / 58) | 0;
}
while (carry > 0) {
result.push(carry % 58);
carry = (carry / 58) | 0;
}
});
result = result.map(function(b) {
return alphabet[b];
}).reverse().join("");
while (result.length < input.length) {
result = alphabet[0] + result;
}
return result;
},
/**
* From Base58 operation.
*
* @param {string} input
* @param {Object[]} args
* @returns {byteArray}
*/
runFrom: function(input, args) {
var alphabet = args[0] || Base58.ALPHABET_OPTIONS[0].value;
if (alphabet.length !== 58 ||
[].unique.call(alphabet).length !== 58) {
throw ("Alphabet must be of length 58");
}
var removeNonAlphaChars = args[1];
if (removeNonAlphaChars === undefined)
removeNonAlphaChars = true;
if (input.length === 0) return [];
var result = [0];
[].forEach.call(input, function(c, charIndex) {
var index = alphabet.indexOf(c);
if (index === -1) {
if (removeNonAlphaChars) {
return;
} else {
throw ("Char " + c + " not in alphabet");
}
}
var carry = result[0] * 58 + index;
result[0] = carry & 0xFF;
carry = carry >> 8;
for (var i = 1; i < result.length; i++) {
carry += result[i] * 58;
result[i] = carry & 0xFF;
carry = carry >> 8;
}
while (carry > 0) {
result.push(carry & 0xFF);
carry = carry >> 8;
}
});
return result.reverse();
},
};