'UnsafePointer<UInt8>' 无法转换为 'UnsafePointer<_>'。

Question

我正在进行TripleDES加密和解密。出现了以下错误：

UnsafePointer<UInt8>无法转换为UnsafePointer<_>

出现错误的代码如下：

        let keyString        = "25d1d4cb0a08403e2acbcbe0"
        let keyData = keyString.data(using: .utf8)!
        let message       = pass
        let data = message.data(using: .utf8)!
        let cryptData    = NSMutableData(length: Int(data.count) + kCCBlockSize3DES)!
        let keyLength              = size_t(kCCKeySize3DES)
        let operation: CCOperation = UInt32(kCCEncrypt)
        let algoritm:  CCAlgorithm = UInt32(kCCAlgorithm3DES)
        let options:   CCOptions   = UInt32(kCCOptionECBMode + kCCOptionPKCS7Padding)

        var numBytesEncrypted :size_t = 0

        let cryptStatus = keyData.withUnsafeBytes { (keyBytes: UnsafePointer<UInt8>) in
            data.withUnsafeBytes { (dataBytes: UnsafePointer<UInt8>) in
                cryptData.withUnsafeMutableBytes { (cryptBytes: UnsafeMutablePointer<UInt8>) in
                    CCCrypt(operation,
                            algoritm,
                            options,
                            keyBytes,
                            keyLength,
                            nil,
                            dataBytes,
                            data.count,
                            cryptBytes,
                            cryptData.count,
                            &numBytesEncrypted)
                }
            }
        }

有人可以帮忙吗？

- Rohitax Rajguru

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@kevin 已更新代码。 - Rohitax Rajguru

我有一个非常类似的问题。你最后解决了吗？ - user1055568

Answer 1

这个错误信息是编译器的一种错误，导致编译器无法编译代码并发出无效和误导性的错误信息。此外，请参见https://bugs.swift.org/browse/SR-5931 在大多数情况下，您可以：

- 删除类型注释（），以显示真正的原因 - 修复原因 - 再次添加类型注释

- Codo

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有人能提供实际的解决方案吗？当我在我的代码中删除<UInt8>时，编译器会崩溃，因此我永远无法看到“原因”。 - uliwitness

Answer 2

    let keyString        = "25d1d4cb0a08403e2acbcbe0"
    let keyData = keyString.data(using: .utf8)!
    let message       = pass
    let data = message.data(using: .utf8)!
    let cryptData    = NSMutableData(length: Int(data.count) + kCCBlockSize3DES)!
    let keyLength              = size_t(kCCKeySize3DES)
    let operation: CCOperation = UInt32(kCCEncrypt)
    let algoritm:  CCAlgorithm = UInt32(kCCAlgorithm3DES)
    let options:   CCOptions   = UInt32(kCCOptionECBMode + kCCOptionPKCS7Padding)

    var numBytesEncrypted :size_t = 0

    let cryptStatus = keyData.withUnsafeBytes { (keyBytes: UnsafePointer<UInt8>) in
        data.withUnsafeBytes { (dataBytes: UnsafePointer<UInt8>) in
            cryptData.withUnsafeMutableBytes { (cryptBytes: UnsafeMutablePointer<UInt8>) in
                CCCrypt(operation,
                        algoritm,
                        options,
                        keyBytes,
                        keyLength,
                        nil,
                        dataBytes,
                        data.count,
                        &cryptBytes, //<-----try to do this
                        cryptData.count,
                        &numBytesEncrypted)
            }
        }
    }

- Master-Yi

Answer 3

cryptData 是一个 NSMutableData 对象，因此它具有 mutableBytes 可供使用。

那么怎么样：

    let keyString        = "25d1d4cb0a08403e2acbcbe0"
    let keyData = keyString.data(using: .utf8)!
    let message       = pass
    let data = message.data(using: .utf8)!
    let cryptData    = NSMutableData(length: Int(data.count) + kCCBlockSize3DES)!
    let keyLength              = size_t(kCCKeySize3DES)
    let operation: CCOperation = UInt32(kCCEncrypt)
    let algoritm:  CCAlgorithm = UInt32(kCCAlgorithm3DES)
    let options:   CCOptions   = UInt32(kCCOptionECBMode + kCCOptionPKCS7Padding)

    var numBytesEncrypted :size_t = 0

    let cryptStatus = keyData.withUnsafeBytes { (keyBytes : UnsafePointer<UInt8>) in
        data.withUnsafeBytes { (dataBytes : UnsafePointer<UInt8>) in

            CCCrypt(operation,
                    algoritm,
                    options,
                    keyBytes,
                    keyLength,
                    nil,
                    dataBytes,
                    data.count,
                    cryptData.mutableBytes,
                    cryptData.length,
                    &numBytesEncrypted)

        }
    }

    if UInt32(cryptStatus) == UInt32(kCCSuccess) {
        print("success!")
    }

- Michael Dautermann

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这个答案并没有真正帮助我理解问题出在哪里。:( - Andrew K