com.eduworks.ec.crypto.EcAesCtr Maven / Gradle / Ivy
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package com.eduworks.ec.crypto;
import com.eduworks.ec.remote.EcLevrHttp;
import forge.cipher;
import forge.cipheroutput;
import forge.util;
import org.stjs.javascript.Global;
import org.stjs.javascript.JSObjectAdapter;
import window.EcLevrCrypto;
/**
* Encrypts data synchronously using AES-256-CTR. Requires secret and iv to be 32 bytes.
* Output is encoded in base64 for easier handling.
*
* @author fritz.ray@eduworks.com
* @module com.eduworks.ec
* @class EcAesCtr
*/
public class EcAesCtr {
/**
* Encrypts plaintext using AES-256-CTR.
* Plaintext is treated as as a sequence of bytes, does not perform UTF8 decoding.
* Returns base64 encoded ciphertext.
*
* @param {string} plaintext Text to encrypt.
* @param {string} secret Secret to use to encrypt.
* @param {string} iv Initialization Vector to use to encrypt.
* @return {string} Ciphertext encoded using base64.
* @method encrypt
* @static
*/
public static String encrypt(String plaintext, String secret, String iv) {
//Key creation was 32 byte at some point instead of 16 byte. Whoops.
if (Global.typeof(EcLevrHttp.httpStatus) != "undefined" && util.decode64(secret).length == 16 && util.decode64(iv).length == 16)
return EcLevrCrypto.aesEncrypt(plaintext, iv, secret);
cipher c = cipher.createCipher("AES-CTR", util.decode64(secret));
c.start(new EcAesParameters(iv));
c.update(util.createBuffer(util.encodeUtf8(plaintext)));
c.finish();
cipheroutput encrypted = c.output;
return util.encode64(encrypted.bytes());
}
/**
* Decrypts ciphertext using AES-256-CTR.
* Ciphertext must be base64 encoded ciphertext.
* Returns plaintext as a string (Sequence of bytes, no encoding).
*
* @param {string} ciphertext Ciphertext to decrypt.
* @param {string} secret Secret to use to decrypt.
* @param {string} iv Initialization Vector to use to decrypt.
* @return {string} Plaintext with no encoding.
* @method decrypt
* @static
*/
public static String decrypt(String ciphertext, String secret, String iv) {
if (EcCrypto.caching) {
final Object cacheGet = JSObjectAdapter.$get(EcCrypto.decryptionCache, secret + iv + ciphertext);
if (cacheGet != null)
return (String) cacheGet;
}
//Key creation was 32 byte at some point instead of 16 byte. Whoops.
if (Global.typeof(EcLevrHttp.httpStatus) != "undefined" && util.decode64(secret).length == 16 && util.decode64(iv).length == 16) {
String result = EcLevrCrypto.aesDecrypt(ciphertext, iv, secret);
if (EcCrypto.caching)
JSObjectAdapter.$put(EcCrypto.decryptionCache, secret + iv + ciphertext, result);
return result;
}
cipher c = cipher.createDecipher("AES-CTR", util.decode64(secret));
c.start(new EcAesParameters(iv));
c.update(forge.util.createBuffer(forge.util.decode64(ciphertext)));
c.finish();
cipheroutput decrypted = c.output;
if (EcCrypto.caching)
JSObjectAdapter.$put(EcCrypto.decryptionCache, secret + iv + ciphertext, util.decodeUtf8(decrypted.data));
return util.decodeUtf8(decrypted.data);
}
}