Android加密算法之AES 什么是高级加密标准或AES？AES加密标准又称为高级加密标准Rijndael加密法，是美国国家标准技术研究所NIST旨在取代DES的21世纪的加密标准。AES加密如何工作？AES是一种对称的加密算法，可基于相同的密钥进行加密和解密。AES包含三个分组密码：AES-128，AES-192和AES-256。每个密码分别使用128 位，192位和256位的加密密钥对128 位块中的数据进行加密和解密。代码：object AESCrypt { private const val AES_MODE = "AES/CBC/PKCS7Padding" //"算法/模式/补码方式" private const val CHARSET = "UTF-8" private const val CIPHER = "AES" private const val HASH_ALGORITHM = "SHA-256" private val IV_BYTES = byteArrayOf(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00) /** * Generates SHA256 hash of the password which is used as key * * @param password used to generated key * @return SHA256 of the password */ @Throws(NoSuchAlgorithmException::class, UnsupportedEncodingException::class) private fun generateKey(password: String): SecretKeySpec { val digest = MessageDigest.getInstance(HASH_ALGORITHM) val bytes = password.toByteArray(charset(CHARSET)) digest.update(bytes, 0, bytes.size) val key = digest.digest() return SecretKeySpec(key, CIPHER) } /** * Encrypt and encode message using 256-bit AES with key generated from password. * * @param password used to generated key * @param message the thing you want to encrypt assumed String UTF-8 * @return Base64 encoded CipherText * @throws GeneralSecurityException if problems occur during encryption */ @Throws(GeneralSecurityException::class) fun encrypt(password: String, message: String): String { try { val key = generateKey(password) val cipherText = encrypt(key, IV_BYTES, message.toByteArray(charset(CHARSET))) //NO_WRAP is important as was getting \n at the end return Base64.encodeToString(cipherText, Base64.NO_WRAP) } catch (e: UnsupportedEncodingException) { throw GeneralSecurityException(e) } } /** * More flexible AES encrypt that doesn't encode * * @param key AES key typically 128, 192 or 256 bit * @param iv Initiation Vector * @param message in bytes (assumed it's already been decoded) * @return Encrypted cipher text (not encoded) * @throws GeneralSecurityException if something goes wrong during encryption */ @Throws(GeneralSecurityException::class) fun encrypt(key: SecretKeySpec, iv: ByteArray, message: ByteArray): ByteArray { val cipher = Cipher.getInstance(AES_MODE) val ivSpec = IvParameterSpec(iv) cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec) return cipher.doFinal(message) } /** * Decrypt and decode ciphertext using 256-bit AES with key generated from password * * @param password used to generated key * @param base64EncodedCipherText the encrpyted message encoded with base64 * @return message in Plain text (String UTF-8) * @throws GeneralSecurityException if there's an issue decrypting */ @Throws(GeneralSecurityException::class) fun decrypt(password: String, base64EncodedCipherText: String): String { try { val key = generateKey(password) val decodedCipherText = Base64.decode(base64EncodedCipherText, Base64.NO_WRAP) val decryptedBytes = decrypt(key, IV_BYTES, decodedCipherText) return String(decryptedBytes, charset(CHARSET)) } catch (e: UnsupportedEncodingException) { throw GeneralSecurityException(e) } } /** * More flexible AES decrypt that doesn't encode * * @param key AES key typically 128, 192 or 256 bit * @param iv Initiation Vector * @param decodedCipherText in bytes (assumed it's already been decoded) * @return Decrypted message cipher text (not encoded) * @throws GeneralSecurityException if something goes wrong during encryption */ @Throws(GeneralSecurityException::class) fun decrypt(key: SecretKeySpec, iv: ByteArray, decodedCipherText: ByteArray): ByteArray { val cipher = Cipher.getInstance(AES_MODE) val ivSpec = IvParameterSpec(iv) cipher.init(Cipher.DECRYPT_MODE, key, ivSpec) return cipher.doFinal(decodedCipherText) } }添加扩展方法，方便调用private const val key: String = "Your AES Key" fun encrypt(input: String): String { return AESCrypt.encrypt(key, input) } fun decrypt(input: String): String { return AESCrypt.decrypt(key, input) } fun String.aesEncrypt(): String = encrypt(this) fun String.aesDecrypt(): String = decrypt(this)使用方法"明文".aesEncrypt() "密文".aesDecrypt()