77 lines
2.5 KiB
JavaScript
77 lines
2.5 KiB
JavaScript
(function () {
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'use strict';
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var crypto = window.crypto;
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var Unibabel = window.Unibabel;
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function deriveKey(saltHex, passphrase, iter) {
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var keyLenBits = 128;
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var kdfname = "PBKDF2";
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var aesname = "AES-CBC"; // AES-CTR is also popular
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// 100 - probably safe even on a browser running from a raspberry pi using pure js ployfill
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// 10000 - no noticeable speed decrease on my MBP
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// 100000 - you can notice
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// 1000000 - annoyingly long
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var iterations = iter || 100; // something a browser on a raspberry pi or old phone could do
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var hashname = "SHA-256";
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var extractable = true;
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console.log('');
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console.log('passphrase', passphrase);
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console.log('salt (hex)', saltHex);
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//console.log('salt (hex)', Unibabel.bufferToHex(saltBuf));
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console.log('iterations', iterations);
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console.log('keyLen (bytes)', keyLenBits / 8);
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console.log('digest', hashname);
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// First, create a PBKDF2 "key" containing the password
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return crypto.subtle.importKey(
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"raw",
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Unibabel.utf8ToBuffer(passphrase),
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{ "name": kdfname },
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false,
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["deriveKey"]).
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// Derive a key from the password
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then(function (passphraseKey) {
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return crypto.subtle.deriveKey(
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{ "name": kdfname
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, "salt": Unibabel.hexToBuffer(saltHex)
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, "iterations": iterations
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, "hash": hashname
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}
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, passphraseKey
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// required to be 128 or 256 bits
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, { "name": aesname, "length": keyLenBits } // Key we want
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, extractable // Extractble
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, [ "encrypt", "decrypt" ] // For new key
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);
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}).
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// Export it so we can display it
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then(function (aesKey) {
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return crypto.subtle.exportKey("raw", aesKey).then(function (arrbuf) {
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return new Uint8Array(arrbuf);
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});
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}).
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catch(function (err) {
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window.alert("Key derivation failed: " + err.message);
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});
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}
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function test() {
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// Part of the salt is application-specific (same on iOS, Android, and Web)
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var saltHex = '942c2db750b5f57f330226b2b498c6d3';
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var passphrase = 'Pizzas are like children';
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//var passphrase = "I'm a ☢ ☃ who speaks 中国语文!";
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var iter = 1672;
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// NOTE: the salt will be truncated to the length of the hash algo being used
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return deriveKey(saltHex, passphrase, iter).then(function (keyBuf) {
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var hexKey = Unibabel.bufferToHex(keyBuf);
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console.log('[TEST] hexKey');
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console.log(hexKey);
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});
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}
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test();
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}());
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