Question

我有一个3DES加密的例子，我必须遵循它才能在NFC卡上进行身份验证。以下是示例：

因此51E764602678DF2B变为577293FD2F34CA51，密钥= 49454D4B41455242214E4143554F5946且IV = 0000000000000000 我成功地在这个网站上得到了正确的结果： http://tripledes.online-domain-tools.com/

我尝试使用https://github.com/sgl0v/SCrypto进行快速扫描，如下所示：

func testScrypto() {
    let plaintext = "51E764602678DF2B".data(using: String.Encoding.utf8)!
    let sharedSecretKey = "49454D4B41455242214E4143".data(using: String.Encoding.utf8)!
    let IV = "0000000000000000".data(using: String.Encoding.utf8)!

    let ciphertext = try! plaintext.encrypt(.tripleDES, options: .PKCS7Padding, key: sharedSecretKey, iv: IV)     

    let plaintext2 = try! ciphertext.decrypt(.tripleDES, options: .PKCS7Padding, key: sharedSecretKey, iv: IV)

    print("cipher = \(ciphertext.hexString())")
    print("plaintext2 = \(plaintext2.hexString())")
}

public extension Data {

func bytesArray<T: ExpressibleByIntegerLiteral>() -> [T] {
    var bytes = Array<T>(repeating: 0, count: self.count)
    (self as NSData).getBytes(&bytes, length:self.count * MemoryLayout<T>.size)
    return bytes
}

func hexString() -> String {
    let hexString = NSMutableString()
    let bytes: [UInt8] = self.bytesArray()
    for byte in bytes {
        hexString.appendFormat("%02x", UInt(byte))
    }
    return hexString as String
}
}

结果是：

cipher = d4c4a9637bcb4a435982330a42d1357b9e4539886a983535
plaintext2 = 35314537363436303236373844463242

35314537363436303236373844463242是51E764602678DF2B，如果我从hexstring转换为明文但其他字符串根本不是577293FD2F34CA51

我也试过这个lib https://www.example-code.com/swift/crypt2_3des.asp 但结果仍然是错误的

我不知道是否有人知道如何在swift上执行此操作或者是加密专家？

谢谢！

Answer 1

已提供的明文数据和密钥以十六进制编码。然而，您将它们编码为UTF-8文本，这不是一回事。

Answer 2

我成功解决了这个问题问题是密钥只有16个字节，需要24个，所以我猜它是随机填充的，但是为了做24个，它预计是在16个末尾放回的前8个字节？ / p> 像这样工作：

func fillKey(keyLength: size_t, key: Data) -> Data {
    let missingBytes = keyLength - key.count
    if missingBytes > 0 {
        let keyBytes = (key as NSData).bytes
        var bytes = [UInt8](repeating: UInt8(0), count: keyLength)
        memccpy(&bytes[0], keyBytes.advanced(by: 0), Int32(key.count), key.count)
        memccpy(&bytes[key.count], keyBytes.advanced(by: 0), Int32(missingBytes), missingBytes)
        return Data(bytes: bytes)
    } else {
        return key
    }
}

func my3DESEncrypt(encryptData: String, key: String, iv: String) -> Data? {
    var myKeyData : Data = key.hexadecimal()!
    let myIvData : Data = iv.hexadecimal()!
    var myRawData : Data = encryptData.hexadecimal()!
    let buffer_size : size_t = myRawData.count + kCCBlockSize3DES
    var buffer = [UInt8](repeating: UInt8(0), count: buffer_size)
    var num_bytes_encrypted : size_t = 0

    let operation: CCOperation = UInt32(kCCEncrypt)
    let algoritm:  CCAlgorithm = UInt32(kCCAlgorithm3DES)
    let options:   CCOptions   = 0
    let keyLength        = size_t(kCCKeySize3DES)

    myKeyData = self.fillKey(keyLength: keyLength, key: myKeyData)
    let Crypto_status: CCCryptorStatus = CCCrypt(operation, algoritm, options, (myKeyData as NSData).bytes, keyLength, (myIvData as NSData).bytes, (myRawData as NSData).bytes, myRawData.count, &buffer, buffer_size, &num_bytes_encrypted)
    if UInt32(Crypto_status) == UInt32(kCCSuccess) {
        let data = Data(bytes: buffer, count: num_bytes_encrypted)
        return data
    } else{
        return nil
    }
}


func my3DESDecrypt(decryptData : Data, key: String, iv: String) -> Data? {
    let mydata_len : Int = decryptData.count
    var myKeyData : Data = key.hexadecimal()!
    let myIvData : Data = iv.hexadecimal()!

    let buffer_size : size_t = mydata_len+kCCBlockSize3DES
    var buffer = [UInt8](repeating: UInt8(0), count: buffer_size)
    var num_bytes_encrypted : size_t = 0

    let operation: CCOperation = UInt32(kCCDecrypt)
    let algoritm:  CCAlgorithm = UInt32(kCCAlgorithm3DES)
    let options:   CCOptions   = UInt32(kCCOptionPKCS7Padding)
    let keyLength        = size_t(kCCKeySize3DES)


    myKeyData = self.fillKey(keyLength: keyLength, key: myKeyData)
    let decrypt_status : CCCryptorStatus = CCCrypt(operation, algoritm, options, (myKeyData as NSData).bytes, keyLength, (myIvData as NSData).bytes, (decryptData as NSData).bytes, mydata_len, &buffer, buffer_size, &num_bytes_encrypted)

    if UInt32(decrypt_status) == UInt32(kCCSuccess){
        let data = Data(bytes: buffer, count: num_bytes_encrypted)
        return data
    } else{
        return nil

    }
}

3DES加密结果与示例不同

2 个答案: