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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()
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解决NestedScrollView嵌套RecyclerView滚动监听问题 不使用recyclerview的监听，直接用NestedScrollView的监听scrollView.setOnScrollChangeListener( NestedScrollView.OnScrollChangeListener { v, scrollX, scrollY, oldScrollX, oldScrollY -> if (scrollY > oldScrollY) { Log.i(TAG, "Scroll DOWN") } if (scrollY < oldScrollY) { Log.i(TAG, "Scroll UP") } if (scrollY == 0) { Log.i(TAG, "TOP SCROLL") } if (scrollY == v.getChildAt(0).measuredHeight - v.measuredHeight) { Log.i(TAG, "BOTTOM SCROLL") } })
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android加密算法之MD5 方法1fun getMD5A(str: String): String? { return try { val md: MessageDigest = MessageDigest.getInstance("MD5")//生成一个MD5加密计算摘要 md.update(str.toByteArray()) //计算md5函数 var md5Str: String = BigInteger(1, md.digest()).toString(16) if (md5Str.length < 32) { md5Str = "0$md5Str" } md5Str } catch (e: Exception) { throw Exception("MD5加密出现错误") } }方法2，修改hexDigits可生所不同的字符串：例如：charArrayOf('5','2','0','1','3','1','4','7','8','9','a','b','c','d','e','f')fun getMD5B(str: String): String? { val hexDigits = charArrayOf('0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f') return try { val mdInst = MessageDigest.getInstance("MD5") mdInst.update(str.toByteArray()) val md = mdInst.digest() val j = md.size val str = CharArray(j * 2) var k = 0 for (i in 0 until j) { val byte0 = md[i] str[k++] = hexDigits[byte0.toInt().ushr(4) and 0xf] str[k++] = hexDigits[byte0.toInt().and(0xf)] } String(str) } catch (e: java.lang.Exception) { e.printStackTrace() null } }
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Yii2中$model->load(Yii::$app->request->get())一直返回false 使用$model->load()方法时一直返回false，网上找许久，有说是安全问题的，加个参数就可以了，于是：$model->load(Yii::$app->request->get(),true)可还是没有解决，看代码：public function load($data, $formName = null) { $scope = $formName === null ? $this->formName() : $formName; if ($scope === '' && !empty($data)) { $this->setAttributes($data); return true; } elseif (isset($data[$scope])) { $this->setAttributes($data[$scope]); return true; } return false; }load()方法有两个参数，第一个参数 $data 是要填充的数据，第二个参数 $formName 是选择指定的模型。如果第二个参数不传，$formName 会默认为null，默认取当前模型 $this->formName()。如果指定了模型，会将模型名称作为key值，通过 $data[$formName] 取值，也就是这时候应该传的 $data 格式是：$data = [ 'User' => [ 'name' => 'test', 'phone' => '13000000000', 'email' => '[email protected]' ] ];如果 $formName 传空字符串，则 $data 传递参数格式为：$data = [ 'name' => 'test', 'phone' => '13000000000', 'email' => '[email protected]' ];这时应该用:$model->load($data, '');还有一种解决办法:$model->attributes = $data; // 或者 $model->setAttributes($data);
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