Question

我尝试使用IDZSwiftCommonCrypto CommonCrypto的包装器在Swift 4中实现AES 256 CTR模式解密文件。问题是我将'未实现'作为返回状态，尽管看起来这种模式在CommonCrypto中实现。

import Foundation
import IDZSwiftCommonCrypto

let tmp = NSTemporaryDirectory() as NSString
let encryptedFilePath = Bundle.main.path(forResource: "encrypted", ofType: "pdfenc")
var decryptedFilePath = "\(tmp)test.pdf"

var encryptedFileInputStream = InputStream(fileAtPath: encryptedFilePath)!
var decryptedFileOutputStream = OutputStream(toFileAtPath: decryptedFilePath, append:false)!

let keyK = "4c7b3180a4dca6ece2d051811a7b9ca23f210e28ceabd92c5d171e567875f70b" // Key used to encrypt the file
let tkeyK = arrayFrom(hexString: keyK)

let iv = Array<UInt8>() // It's far less secure to not use an IV but it's not necessary 
let bufferSize = 1024
let sc = StreamCryptor(operation: StreamCryptor.Operation.decrypt, algorithm: StreamCryptor.Algorithm.aes, mode: StreamCryptor.Mode.CTR, padding: StreamCryptor.Padding.NoPadding, key: tkeyK, iv: iv)


var inputBuffer = Array<UInt8>(repeating:0, count:1024)
var outputBuffer = Array<UInt8>(repeating:0, count:1024)
encryptedFileInputStream.open()
decryptedFileOutputStream.open()

var cryptedBytes : Int = 0

while encryptedFileInputStream.hasBytesAvailable {
    let bytesRead = encryptedFileInputStream.read(&inputBuffer, maxLength: inputBuffer.count)
    let status = sc.update(bufferIn: inputBuffer, byteCountIn: bytesRead, bufferOut: &outputBuffer, byteCapacityOut: outputBuffer.count, byteCountOut: &cryptedBytes)
    assert(status == Status.success)
    if(cryptedBytes > 0) {
        let bytesWritten = decryptedFileOutputStream.write(outputBuffer, maxLength: Int(cryptedBytes))
        assert(bytesWritten == Int(cryptedBytes))
    }
}

let status = sc.final(bufferOut: &outputBuffer, byteCapacityOut: outputBuffer.count, byteCountOut: &cryptedBytes)
assert(status == Status.success)
if(cryptedBytes > 0) {
    let bytesWritten = decryptedFileOutputStream.write(outputBuffer, maxLength: Int(cryptedBytes))
    assert(bytesWritten == Int(cryptedBytes))
}

encryptedFileInputStream.close()
decryptedFileOutputStream.close()

有关测试此代码的更多信息，请参阅this GitHub repo。

我必须使用Node.js解密已在服务器上加密的文件（在客户端上）。

AES 256 CTR在Swift中解密

0 个答案: