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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
export var MailCryptoUtils = {
/**
* Converts a binary string into a Uint8Array.
*
* @param {BinaryString} str - The string to convert.
* @returns {Uint8Array}.
*/
binaryStringToTypedArray(str) {
const arr = new Uint8Array(str.length);
for (let i = 0; i < str.length; i++) {
arr[i] = str.charCodeAt(i);
}
return arr;
},
/**
* The HMAC-MD5 transform works like:
*
* MD5(K XOR opad, MD5(K XOR ipad, m))
*
* where
* K is an n byte key
* ipad is the byte 0x36 repeated 64 times
* opad is the byte 0x5c repeated 64 times
* m is the message being processed
* @param {Uint8Array} key
* @param {Uint8Array} data
* @returns {Uint8Array}
*/
hmacMd5(key, data) {
const hasher = Cc["@mozilla.org/security/hash;1"].createInstance(
Ci.nsICryptoHash
);
let digest;
// If key is longer than 64 bytes, reset it to MD5(key).
if (key.length > 64) {
hasher.init(Ci.nsICryptoHash.MD5);
hasher.update(key, key.length);
digest = hasher.finish(false);
key = this.binaryStringToTypedArray(digest);
}
// Generate innerPad and outerPad.
const innerPad = new Uint8Array(64);
const outerPad = new Uint8Array(64);
for (let i = 0; i < 64; i++) {
const base = key[i] || 0;
innerPad[i] = base ^ 0x36;
outerPad[i] = base ^ 0x5c;
}
// Perform inner MD5.
hasher.init(Ci.nsICryptoHash.MD5);
hasher.update(innerPad, 64);
hasher.update(data, data.length);
digest = hasher.finish(false);
const result = this.binaryStringToTypedArray(digest);
// Perform outer MD5.
hasher.init(Ci.nsICryptoHash.MD5);
hasher.update(outerPad, 64);
hasher.update(result, result.length);
digest = hasher.finish(false);
return this.binaryStringToTypedArray(digest);
},
};