Helper Added: CryptoJS (#1237)

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Ömer Faruk Sancak 2024-08-02 01:13:54 +03:00 committed by GitHub
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package com.lagradost.cloudstream3.extractors.helper
import java.util.Arrays
import java.util.Base64
import java.security.MessageDigest
import java.security.SecureRandom
import javax.crypto.Cipher
import javax.crypto.spec.SecretKeySpec
import javax.crypto.spec.IvParameterSpec
import java.nio.charset.StandardCharsets
import kotlin.math.min
/**
* Conforming with CryptoJS AES method
*/
// see https://gist.github.com/thackerronak/554c985c3001b16810af5fc0eb5c358f
@Suppress("unused", "FunctionName", "SameParameterValue")
object CryptoJS {
private const val KEY_SIZE = 256
private const val IV_SIZE = 128
private const val HASH_CIPHER = "AES/CBC/PKCS7Padding"
private const val AES = "AES"
private const val KDF_DIGEST = "MD5"
// Seriously crypto-js, what's wrong with you?
private const val APPEND = "Salted__"
/**
* Encrypt
* @param password passphrase
* @param plainText plain string
*/
fun encrypt(password: String, plainText: String): String {
val saltBytes = generateSalt(8)
val key = ByteArray(KEY_SIZE / 8)
val iv = ByteArray(IV_SIZE / 8)
evpkdf(password.toByteArray(), KEY_SIZE, IV_SIZE, saltBytes, key, iv)
val keyS = SecretKeySpec(key, AES)
val cipher = Cipher.getInstance(HASH_CIPHER)
val ivSpec = IvParameterSpec(iv)
cipher.init(Cipher.ENCRYPT_MODE, keyS, ivSpec)
val cipherText = cipher.doFinal(plainText.toByteArray())
// Thanks kientux for this: https://gist.github.com/kientux/bb48259c6f2133e628ad
// Create CryptoJS-like encrypted!
val sBytes = APPEND.toByteArray()
val b = ByteArray(sBytes.size + saltBytes.size + cipherText.size)
System.arraycopy(sBytes, 0, b, 0, sBytes.size)
System.arraycopy(saltBytes, 0, b, sBytes.size, saltBytes.size)
System.arraycopy(cipherText, 0, b, sBytes.size + saltBytes.size, cipherText.size)
val bEncode = Base64.getEncoder().encode(b)
return String(bEncode)
}
/**
* Decrypt
* Thanks Artjom B. for this: http://stackoverflow.com/a/29152379/4405051
* @param password passphrase
* @param cipherText encrypted string
*/
fun decrypt(password: String, cipherText: String): String {
val ctBytes = Base64.getDecoder().decode(cipherText.toByteArray())
val saltBytes = Arrays.copyOfRange(ctBytes, 8, 16)
val cipherTextBytes = Arrays.copyOfRange(ctBytes, 16, ctBytes.size)
val key = ByteArray(KEY_SIZE / 8)
val iv = ByteArray(IV_SIZE / 8)
evpkdf(password.toByteArray(), KEY_SIZE, IV_SIZE, saltBytes, key, iv)
val cipher = Cipher.getInstance(HASH_CIPHER)
val keyS = SecretKeySpec(key, AES)
cipher.init(Cipher.DECRYPT_MODE, keyS, IvParameterSpec(iv))
val plainText = cipher.doFinal(cipherTextBytes)
return String(plainText)
}
private fun evpkdf(password: ByteArray, keySize: Int, ivSize: Int, salt: ByteArray, resultKey: ByteArray, resultIv: ByteArray): ByteArray {
return evpkdf(password, keySize, ivSize, salt, 1, KDF_DIGEST, resultKey, resultIv)
}
@Suppress("NAME_SHADOWING")
private fun evpkdf(password: ByteArray, keySize: Int, ivSize: Int, salt: ByteArray, iterations: Int, hashAlgorithm: String, resultKey: ByteArray, resultIv: ByteArray): ByteArray {
val keySize = keySize / 32
val ivSize = ivSize / 32
val targetKeySize = keySize + ivSize
val derivedBytes = ByteArray(targetKeySize * 4)
var numberOfDerivedWords = 0
var block: ByteArray? = null
val hash = MessageDigest.getInstance(hashAlgorithm)
while (numberOfDerivedWords < targetKeySize) {
if (block != null) {
hash.update(block)
}
hash.update(password)
block = hash.digest(salt)
hash.reset()
// Iterations
for (i in 1 until iterations) {
block = hash.digest(block!!)
hash.reset()
}
System.arraycopy(
block!!, 0, derivedBytes, numberOfDerivedWords * 4,
min(block.size, (targetKeySize - numberOfDerivedWords) * 4)
)
numberOfDerivedWords += block.size / 4
}
System.arraycopy(derivedBytes, 0, resultKey, 0, keySize * 4)
System.arraycopy(derivedBytes, keySize * 4, resultIv, 0, ivSize * 4)
return derivedBytes // key + iv
}
private fun generateSalt(length: Int): ByteArray {
return ByteArray(length).apply {
SecureRandom().nextBytes(this)
}
}
}