Question

我在Kotlin中创建了这两个扩展名来加密/解密字符串：

fun String.encrypt(seed : String): String {
    val keyGenerator = KeyGenerator.getInstance("AES")
    val secureRandom = SecureRandom.getInstance("SHA1PRNG")
    secureRandom.setSeed(seed.toByteArray())

    keyGenerator.init(128, secureRandom)
    val skey = keyGenerator.generateKey()
    val rawKey : ByteArray = skey.encoded

    val skeySpec = SecretKeySpec(rawKey, "AES")
    val cipher = Cipher.getInstance("AES/CBC/PKCS5Padding")
    cipher.init(Cipher.ENCRYPT_MODE, skeySpec)
    val byteArray = cipher.doFinal(this.toByteArray())

    return byteArray.toString()
}

fun String.decrypt(seed : String): String {
    val keyGenerator = KeyGenerator.getInstance("AES")
    val secureRandom = SecureRandom.getInstance("SHA1PRNG")
    secureRandom.setSeed(seed.toByteArray())

    keyGenerator.init(128, secureRandom)
    val skey = keyGenerator.generateKey()
    val rawKey : ByteArray = skey.encoded

    val skeySpec = SecretKeySpec(rawKey, "AES")
    val cipher = Cipher.getInstance("AES/CBC/PKCS5Padding")
    cipher.init(Cipher.DECRYPT_MODE, skeySpec)
    val byteArray = cipher.doFinal(this.toByteArray())

    return byteArray.toString()
}

出于某种原因，我得到以下异常：

javax.crypto.IllegalBlockSizeException: last block incomplete in decryption

我做错了什么？

Answer 1

使用base64密钥，salt和iv（初始化向量）进行AES加密/解密。

object AESEncyption {

const val secretKey = "tK5UTui+DPh8lIlBxya5XVsmeDCoUl6vHhdIESMB6sQ="
const val salt = "QWlGNHNhMTJTQWZ2bGhpV3U=" // base64 decode => AiF4sa12SAfvlhiWu
const val iv = "bVQzNFNhRkQ1Njc4UUFaWA==" // base64 decode => mT34SaFD5678QAZX

fun encrypt(strToEncrypt: String) :  String?
{
    try
    {
        val ivParameterSpec = IvParameterSpec(Base64.decode(iv, Base64.DEFAULT))

        val factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1")
        val spec =  PBEKeySpec(secretKey.toCharArray(), Base64.decode(salt, Base64.DEFAULT), 10000, 256)
        val tmp = factory.generateSecret(spec)
        val secretKey =  SecretKeySpec(tmp.encoded, "AES")

        val cipher = Cipher.getInstance("AES/CBC/PKCS7Padding")
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivParameterSpec)
        return Base64.encodeToString(cipher.doFinal(strToEncrypt.toByteArray(Charsets.UTF_8)), Base64.DEFAULT)
    }
    catch (e: Exception)
    {
        println("Error while encrypting: $e")
    }
    return null
}

fun decrypt(strToDecrypt : String) : String? {
    try
    {

        val ivParameterSpec =  IvParameterSpec(Base64.decode(iv, Base64.DEFAULT))

        val factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1")
        val spec =  PBEKeySpec(secretKey.toCharArray(), Base64.decode(salt, Base64.DEFAULT), 10000, 256)
        val tmp = factory.generateSecret(spec);
        val secretKey =  SecretKeySpec(tmp.encoded, "AES")

        val cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
        cipher.init(Cipher.DECRYPT_MODE, secretKey, ivParameterSpec);
        return  String(cipher.doFinal(Base64.decode(strToDecrypt, Base64.DEFAULT)))
    }
    catch (e : Exception) {
        println("Error while decrypting: $e");
    }
    return null
  }
}

iOS swift

Answer 2

按照Maarten Bodews指南，我将问题解决为：

fun String.encrypt(password: String): String {
    val secretKeySpec = SecretKeySpec(password.toByteArray(), "AES")
    val iv = ByteArray(16)
    val charArray = password.toCharArray()
    for (i in 0 until charArray.size){
        iv[i] = charArray[i].toByte()
    }
    val ivParameterSpec = IvParameterSpec(iv)

    val cipher = Cipher.getInstance("AES/GCM/NoPadding")
    cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec)

    val encryptedValue = cipher.doFinal(this.toByteArray())
    return Base64.encodeToString(encryptedValue, Base64.DEFAULT)
}

fun String.decrypt(password: String): String {
    val secretKeySpec = SecretKeySpec(password.toByteArray(), "AES")
    val iv = ByteArray(16)
    val charArray = password.toCharArray()
    for (i in 0 until charArray.size){
        iv[i] = charArray[i].toByte()
    }
    val ivParameterSpec = IvParameterSpec(iv)

    val cipher = Cipher.getInstance("AES/GCM/NoPadding")
    cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec)

    val decryptedByteValue = cipher.doFinal(Base64.decode(this, Base64.DEFAULT))
    return String(decryptedByteValue)
}

Answer 3

要对密文进行编码，请使用base 64或hexadecimals。 Java API包含Base64类，因此您最好使用它。

byte[]#toString不符合您的预期;它只返回字节数组引用的表示，而不是字节数组的内容。

除此之外：

不要使用SecureRandom派生密钥，尝试查找PBKDF2;
明确使用"AES/GCM/NoPadding";
如果您决定使用CBC（通常不安全），请使用独特的IV和随机IV;
如果没有明确选择邮件的字符编码，请不要使用toByteArray。

Answer 4

在Android中实现AES加密和解密的最简单方法是在您的项目中复制此类。

加密字符串

请先在您的项目中复制AESUtils类，然后您可以像这样使用它。

String encrypted = "";
String sourceStr = "This is any source string";
try {
    encrypted = AESUtils.encrypt(sourceStr);
    Log.d("TEST", "encrypted:" + encrypted);
} catch (Exception e) {
    e.printStackTrace();
}

解密字符串

String encrypted = "ANY_ENCRYPTED_STRING_HERE";
String decrypted = "";
try {
    decrypted = AESUtils.decrypt(encrypted);
    Log.d("TEST", "decrypted:" + decrypted);
} catch (Exception e) {
    e.printStackTrace();
}

AESUtils类

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

public class AESUtils 
{

    private static final byte[] keyValue =
            new byte[]{'c', 'o', 'd', 'i', 'n', 'g', 'a', 'f', 'f', 'a', 'i', 'r', 's', 'c', 'o', 'm'};


    public static String encrypt(String cleartext)
            throws Exception {
        byte[] rawKey = getRawKey();
        byte[] result = encrypt(rawKey, cleartext.getBytes());
        return toHex(result);
    }

    public static String decrypt(String encrypted)
            throws Exception {

        byte[] enc = toByte(encrypted);
        byte[] result = decrypt(enc);
        return new String(result);
    }

    private static byte[] getRawKey() throws Exception {
        SecretKey key = new SecretKeySpec(keyValue, "AES");
        byte[] raw = key.getEncoded();
        return raw;
    }

    private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
        SecretKey skeySpec = new SecretKeySpec(raw, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
        byte[] encrypted = cipher.doFinal(clear);
        return encrypted;
    }

    private static byte[] decrypt(byte[] encrypted)
            throws Exception {
        SecretKey skeySpec = new SecretKeySpec(keyValue, "AES");
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.DECRYPT_MODE, skeySpec);
        byte[] decrypted = cipher.doFinal(encrypted);
        return decrypted;
    }

    public static byte[] toByte(String hexString) {
        int len = hexString.length() / 2;
        byte[] result = new byte[len];
        for (int i = 0; i < len; i++)
            result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2),
                    16).byteValue();
        return result;
    }

    public static String toHex(byte[] buf) {
        if (buf == null)
            return "";
        StringBuffer result = new StringBuffer(2 * buf.length);
        for (int i = 0; i < buf.length; i++) {
            appendHex(result, buf[i]);
        }
        return result.toString();
    }

    private final static String HEX = "0123456789ABCDEF";

    private static void appendHex(StringBuffer sb, byte b) {
        sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f));
    }
}

Answer 5

遵循MarcForn指南，我将其缩减为：

const val encryptionKey = "ENCRYPTION_KEY"

fun String.cipherEncrypt(encryptionKey: String): String? {
    try {
        val secretKeySpec = SecretKeySpec(encryptionKey.toByteArray(), "AES")
        val iv = encryptionKey.toByteArray()
        val ivParameterSpec = IvParameterSpec(iv)

        val cipher = Cipher.getInstance("AES/CBC/PKCS5Padding")
        cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec)

        val encryptedValue = cipher.doFinal(this.toByteArray())
        return Base64.encodeToString(encryptedValue, Base64.DEFAULT)
    } catch (e: Exception) {
        e.message?.let{ Log.e("encryptor", it) }
    }
    return null
}

fun String.cipherDecrypt(encryptionKey: String): String? {
    try {
        val secretKeySpec = SecretKeySpec(encryptionKey.toByteArray(), "AES")
        val iv = encryptionKey.toByteArray()
        val ivParameterSpec = IvParameterSpec(iv)

        val cipher = Cipher.getInstance("AES/CBC/PKCS5Padding")
        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec)

        val decodedValue = Base64.decode(this, Base64.DEFAULT)
        val decryptedValue = cipher.doFinal(decodedValue)
        return String(decryptedValue)
    } catch (e: Exception) {
        e.message?.let{ Log.e("decryptor", it) }
    }
    return null
}

加密/解密字符串Kotlin

5 个答案: