fullstack.web/swa/asn1/index.js
2022-12-22 14:57:51 +08:00

165 lines
5.0 KiB
JavaScript

(typeof define != 'undefined' ? define : function (factory) { 'use strict';
if (typeof module == 'object') factory(function (name) { return require(name); });
else factory(function (name) { return window[name.substring(2)]; });
})(function (require) {
"use strict";
var ASN1 = require('./asn1'),
Base64 = require('./base64'),
Hex = require('./hex'),
maxLength = 10240,
reHex = /^\s*(?:[0-9A-Fa-f][0-9A-Fa-f]\s*)+$/,
tree = id('tree'),
dump = id('dump'),
wantHex = id('wantHex'),
area = id('area'),
file = id('file'),
examples = id('examples'),
hash = null;
require('./dom'); // side effect: augment ASN1
if (!window.console || !window.console.log) // IE8 with closed developer tools
window.console = { log: function () {} };
function id(elem) {
return document.getElementById(elem);
}
function text(el, string) {
if ('textContent' in el)
el.textContent = string;
else
el.innerText = string;
}
function decode(der, offset) {
offset = offset || 0;
tree.innerHTML = '';
dump.innerHTML = '';
try {
var asn1 = ASN1.decode(der, offset);
tree.appendChild(asn1.toDOM());
if (wantHex.checked)
dump.appendChild(asn1.toHexDOM());
var b64 = (der.length < maxLength) ? asn1.toB64String() : '';
if (area.value === '')
area.value = Base64.pretty(b64);
try {
window.location.hash = hash = '#' + b64;
} catch (e) { // fails with "Access Denied" on IE with URLs longer than ~2048 chars
window.location.hash = hash = '#';
}
var endOffset = asn1.posEnd();
if (endOffset < der.length) {
var p = document.createElement('p');
p.innerText = 'Input contains ' + (der.length - endOffset) + ' more bytes to decode.';
var button = document.createElement('button');
button.innerText = 'try to decode';
button.onclick = function () {
decode(der, endOffset);
};
p.appendChild(button);
tree.insertBefore(p, tree.firstChild);
}
} catch (e) {
text(tree, e);
}
}
function decodeText(val) {
try {
var der = reHex.test(val) ? Hex.decode(val) : Base64.unarmor(val);
decode(der);
} catch (e) {
text(tree, e);
dump.innerHTML = '';
}
}
function decodeBinaryString(str) {
var der;
try {
if (reHex.test(str))
der = Hex.decode(str);
else if (Base64.re.test(str))
der = Base64.unarmor(str);
else
der = str;
decode(der);
} catch (e) {
text(tree, 'Cannot decode file.');
dump.innerHTML = '';
}
}
// set up buttons
id('butDecode').onclick = function () { decodeText(area.value); };
id('butClear').onclick = function () {
area.value = '';
file.value = '';
tree.innerHTML = '';
dump.innerHTML = '';
hash = window.location.hash = '';
};
id('butExample').onclick = function () {
console.log('Loading example:', examples.value);
var request = new XMLHttpRequest();
request.open('GET', 'examples/' + examples.value, true);
request.onreadystatechange = function() {
if (this.readyState !== 4)
return;
if (this.status >= 200 && this.status < 400) {
area.value = this.responseText;
decodeText(this.responseText);
} else {
console.log('Error loading example.');
}
};
request.send();
};
// this is only used if window.FileReader
function read(f) {
area.value = ''; // clear text area, will get b64 content
var r = new FileReader();
r.onloadend = function () {
if (r.error)
alert("Your browser couldn't read the specified file (error code " + r.error.code + ").");
else
decodeBinaryString(r.result);
};
r.readAsBinaryString(f);
}
function load() {
if (file.files.length === 0)
alert("Select a file to load first.");
else
read(file.files[0]);
}
function loadFromHash() {
if (window.location.hash && window.location.hash != hash) {
hash = window.location.hash;
// Firefox is not consistent with other browsers and returns an
// already-decoded hash string so we risk double-decoding here,
// but since % is not allowed in base64 nor hexadecimal, it's ok
var val = decodeURIComponent(hash.substr(1));
if (val.length)
decodeText(val);
}
}
function stop(e) {
e.stopPropagation();
e.preventDefault();
}
function dragAccept(e) {
stop(e);
if (e.dataTransfer.files.length > 0)
read(e.dataTransfer.files[0]);
}
// main
if ('onhashchange' in window)
window.onhashchange = loadFromHash;
loadFromHash();
document.ondragover = stop;
document.ondragleave = stop;
if ('FileReader' in window && 'readAsBinaryString' in (new FileReader())) {
file.style.display = 'block';
file.onchange = load;
document.ondrop = dragAccept;
}
});