为什么AES128解密在iPhone上花了这么长时间？
我解密从PHP服务器发送的图像。 我正在使用CryptoSwift库来解密图像，图像作为NSData进来，解密后，我从NSData创build一个UIImage。
但解密需要大约1分10秒，这很慢。 图像数据的大小：
println(imageData.length) result: 32592 我相信这不是一个大文件吗？ 这是我用来解密图像数据的代码：
let aes = AES(key: keyData, iv: ivData, blockMode: .ECB) let decryptedData = aes?.decrypt(encryptedSnap, removePadding: true) let image = UIImage(data: decryptedData!)
我试过在不同的线程上运行这个进程，但是它给出了相同的结果。 当我解密图像时，模拟器使用100％的CPU，大约21.5MB的RAM。
任何帮助表示赞赏，谢谢！
Swift 2.0
下面是一些简单的示例代码，使用ECB模式和128位AES密钥encryption和解密NSData 。
testing代码
let keyString = "M02cnQ51Ji97vwT4" let keyData = (keyString as NSString).dataUsingEncoding(NSUTF8StringEncoding) as NSData! let message = "Don´t try to read this text. Top Secret Stuff" let data = (message as NSString).dataUsingEncoding(NSUTF8StringEncoding) as NSData! print("data: \(data)") if let encryptedData = testCrypt(data, keyData:keyData, operation:UInt32(kCCEncrypt)) { print("encryptedData: \(encryptedData)") if let decryptedData = testCrypt(encryptedData, keyData:keyData, operation:UInt32(kCCDecrypt)) { print("decryptedData: \(decryptedData)") } }
encryption方法：
func testCrypt(data:NSData, keyData:NSData, operation:CCOperation) -> NSData? { let keyBytes = UnsafePointer<UInt8>(keyData.bytes) print("keyLength = \(keyData.length), keyData = \(keyData)") let dataLength = Int(data.length) let dataBytes = UnsafePointer<UInt8>(data.bytes) print("dataLength = \(dataLength), data = \(data)") let cryptData: NSMutableData! = NSMutableData(length: Int(dataLength) + kCCBlockSizeAES128) let cryptPointer = UnsafeMutablePointer<UInt8>(cryptData.mutableBytes) let cryptLength = size_t(cryptData.length) let keyLength = size_t(kCCKeySizeAES128) let algoritm: CCAlgorithm = UInt32(kCCAlgorithmAES128) let options: CCOptions = UInt32(kCCOptionECBMode + kCCOptionPKCS7Padding) var numBytesEncrypted :size_t = 0 let cryptStatus = CCCrypt(operation, algoritm, options, keyBytes, keyLength, nil, dataBytes, dataLength, cryptPointer, cryptLength, &numBytesEncrypted) if UInt32(cryptStatus) == UInt32(kCCSuccess) { cryptData.length = Int(numBytesEncrypted) print("cryptLength = \(numBytesEncrypted), cryptData = \(cryptData)") } else { print("Error: \(cryptStatus)") } return cryptData; }
输出：
data: <446f6ec2 b4742074 72792074 6f207265 61642074 68697320 74657874 2e20546f 70205365 63726574 20537475 6666> keyLength = 16, keyData = <4d303263 6e513531 4a693937 76775434> dataLength = 46, data = <446f6ec2 b4742074 72792074 6f207265 61642074 68697320 74657874 2e20546f 70205365 63726574 20537475 6666> cryptLength = 48, cryptData = <5fd86c65 6544720c 9659b43f 2e77bf8d 9c2373d9 e1042a3d ce9a19f8 2900521e c3f8075a b6866ba5 2fcd5793 bbeb8e0c> encryptedData: <5fd86c65 6544720c 9659b43f 2e77bf8d 9c2373d9 e1042a3d ce9a19f8 2900521e c3f8075a b6866ba5 2fcd5793 bbeb8e0c> keyLength = 16, keyData = <4d303263 6e513531 4a693937 76775434> dataLength = 48, data = <5fd86c65 6544720c 9659b43f 2e77bf8d 9c2373d9 e1042a3d ce9a19f8 2900521e c3f8075a b6866ba5 2fcd5793 bbeb8e0c> cryptLength = 46, cryptData = <446f6ec2 b4742074 72792074 6f207265 61642074 68697320 74657874 2e20546f 70205365 63726574 20537475 6666> decryptedData: <446f6ec2 b4742074 72792074 6f207265 61642074 68697320 74657874 2e20546f 70205365 63726574 20537475 6666>