/**
* Crypto
*
* An abstraction layer to instanciate our crypto algorithms
* Copyright (c) 2007 Henri Torgemane
*
* See LICENSE.txt for full license information.
*/
package com.hurlant.crypto
{
import com.hurlant.crypto.hash.HMAC;
import com.hurlant.crypto.hash.MAC;
import com.hurlant.crypto.hash.IHash;
import com.hurlant.crypto.hash.MD2;
import com.hurlant.crypto.hash.MD5;
import com.hurlant.crypto.hash.SHA1;
import com.hurlant.crypto.hash.SHA224;
import com.hurlant.crypto.hash.SHA256;
import com.hurlant.crypto.prng.ARC4;
import com.hurlant.crypto.rsa.RSAKey;
import com.hurlant.crypto.symmetric.AESKey;
import com.hurlant.crypto.symmetric.BlowFishKey;
import com.hurlant.crypto.symmetric.CBCMode;
import com.hurlant.crypto.symmetric.CFB8Mode;
import com.hurlant.crypto.symmetric.CFBMode;
import com.hurlant.crypto.symmetric.CTRMode;
import com.hurlant.crypto.symmetric.DESKey;
import com.hurlant.crypto.symmetric.ECBMode;
import com.hurlant.crypto.symmetric.ICipher;
import com.hurlant.crypto.symmetric.IMode;
import com.hurlant.crypto.symmetric.IPad;
import com.hurlant.crypto.symmetric.ISymmetricKey;
import com.hurlant.crypto.symmetric.IVMode;
import com.hurlant.crypto.symmetric.NullPad;
import com.hurlant.crypto.symmetric.OFBMode;
import com.hurlant.crypto.symmetric.PKCS5;
import com.hurlant.crypto.symmetric.SimpleIVMode;
import com.hurlant.crypto.symmetric.TripleDESKey;
import com.hurlant.crypto.symmetric.XTeaKey;
import com.hurlant.util.Base64;
import flash.utils.ByteArray;
/**
* A class to make it easy to use the rest of the framework.
* As a side-effect, using this class will cause most of the framework
* to be linked into your application, which is not always what you want.
*
* If you want to optimize your download size, don't use this class.
* (But feel free to read it to get ideas on how to get the algorithm you want.)
*/
public class Crypto
{
private var b64:Base64; // we don't use it, but we want the swc to include it, so cheap trick.
public function Crypto(){
}
/**
* Things that should work, among others:
* "aes"
* "aes-128-ecb"
* "aes-128-cbc"
* "aes-128-cfb"
* "aes-128-cfb8"
* "aes-128-ofb"
* "aes-192-cfb"
* "aes-256-ofb"
* "blowfish-cbc"
* "des-ecb"
* "xtea"
* "xtea-ecb"
* "xtea-cbc"
* "xtea-cfb"
* "xtea-cfb8"
* "xtea-ofb"
* "rc4"
* "simple-aes-cbc"
*/
public static function getCipher(name:String, key:ByteArray, pad:IPad=null):ICipher {
// split name into an array.
var keys:Array = name.split("-");
switch (keys[0]) {
/**
* "simple" is a special case. It means:
* "If using an IV mode, prepend the IV to the ciphertext"
*/
case "simple":
keys.shift();
name = keys.join("-");
var cipher:ICipher = getCipher(name, key, pad);
if (cipher is IVMode) {
return new SimpleIVMode(cipher as IVMode);
} else {
return cipher;
}
/**
* we support both "aes-128" and "aes128"
* Technically, you could use "aes192-128", but you'd
* only be hurting yourself.
*/
case "aes":
case "aes128":
case "aes192":
case "aes256":
keys.shift();
if (key.length*8==keys[0]) {
// support for "aes-128-..." and such.
keys.shift();
}
return getMode(keys[0], new AESKey(key), pad);
break;
case "bf":
case "blowfish":
keys.shift();
return getMode(keys[0], new BlowFishKey(key), pad);
/**
* des-ede and des-ede3 are both equivalent to des3.
* the choice between 2tdes and 3tdes is made based
* on the length of the key provided.
*/
case "des":
keys.shift();
if (keys[0]!="ede" && keys[0]!="ede3") {
return getMode(keys[0], new DESKey(key), pad);
}
if (keys.length==1) {
keys.push("ecb"); // default mode for 2tdes and 3tdes with openssl enc
}
// fall-through to triple des
case "3des":
case "des3":
keys.shift();
return getMode(keys[0], new TripleDESKey(key), pad);
case "xtea":
keys.shift();
return getMode(keys[0], new XTeaKey(key), pad);
break;
/**
* Technically, you could say "rc4-128" or whatever,
* but really, the length of the key is what counts here.
*/
case "rc4":
keys.shift();
return new ARC4(key);
break;
}
return null;
}
/**
* Returns the size of a key for a given cipher identifier.
*/
public static function getKeySize(name:String):uint {
var keys:Array = name.split("-");
switch (keys[0]) {
case "simple":
keys.shift();
return getKeySize(keys.join("-"));
case "aes128":
return 16;
case "aes192":
return 24;
case "aes256":
return 32;
case "aes":
keys.shift();
return parseInt(keys[0])/8;
case "bf":
case "blowfish":
return 16;
case "des":
keys.shift();
switch (keys[0]) {
case "ede":
return 16;
case "ede3":
return 24;
default:
return 8;
}
case "3des":
case "des3":
return 24;
case "xtea":
return 8;
case "rc4":
if (parseInt(keys[1])>0) {
return parseInt(keys[1])/8;
}
return 16; // why not.
}
return 0; // unknown;
}
private static function getMode(name:String, alg:ISymmetricKey, padding:IPad=null):IMode {
switch (name) {
case "ecb":
return new ECBMode(alg, padding);
case "cfb":
return new CFBMode(alg, padding);
case "cfb8":
return new CFB8Mode(alg, padding);
case "ofb":
return new OFBMode(alg, padding);
case "ctr":
return new CTRMode(alg, padding);
case "cbc":
default:
return new CBCMode(alg, padding);
}
}
/**
* Things that should work:
* "md5"
* "sha"
* "sha1"
* "sha224"
* "sha256"
*/
public static function getHash(name:String):IHash {
switch(name) {
case "md2":
return new MD2;
case "md5":
return new MD5;
case "sha": // let's hope you didn't mean sha-0
case "sha1":
return new SHA1;
case "sha224":
return new SHA224;
case "sha256":
return new SHA256;
}
return null;
}
/**
* Things that should work:
* "sha1"
* "md5-64"
* "hmac-md5-96"
* "hmac-sha1-128"
* "hmac-sha256-192"
* etc.
*/
public static function getHMAC(name:String):HMAC {
var keys:Array = name.split("-");
if (keys[0]=="hmac") keys.shift();
var bits:uint = 0;
if (keys.length>1) {
bits = parseInt(keys[1]);
}
return new HMAC(getHash(keys[0]), bits);
}
public static function getMAC(name:String):MAC {
var keys:Array = name.split("-");
if (keys[0]=="mac") keys.shift();
var bits:uint = 0;
if (keys.length > 1) {
bits = parseInt(keys[1]);
}
return new MAC(getHash(keys[0]), bits);
}
public static function getPad(name:String):IPad {
switch(name) {
case "null":
return new NullPad;
case "pkcs5":
default:
return new PKCS5;
}
}
/** mostly useless.
*/
public static function getRSA(E:String, M:String):RSAKey {
return RSAKey.parsePublicKey(M,E);
}
}
}
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