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swift - cccrypt 在 swift 4 中生成奇怪的输出

问题描述

我试图编写一个基于 CCCrypt 的加密（AESCBC256）函数，而 CCCrypt 正在生成一个随机值。

例如，当我将 1234567 传递给函数时，它将为相同的 iv 和 Key 返回“HlFP2rCmycZS1269Cm47Q==”或“TTuSJrBcsOmOCDHc5IQ8Dw==”。

这是iv：b5f89591，关键是：366e9c1b4b2ed2b1daf751d7500aaa01

func encrypt(Value: String)->String{
    let keyData = keyString.data(using: .utf8, allowLossyConversion: false)!
    let iv = SecretKey.data(using: .utf8, allowLossyConversion: false)!
    let message       = SecretKey+Value
    let data = message.data(using: .utf8, allowLossyConversion: false)!
    let cryptData    = NSMutableData(length: Int(data.count) + kCCBlockSizeAES128)!
    let keyLength              = size_t(kCCKeySizeAES256)
    let operation: CCOperation = CCOperation(UInt32(kCCEncrypt))
    let algoritm:  CCAlgorithm = CCAlgorithm(UInt32(kCCAlgorithmAES128))
    let options:   CCOptions   = CCOptions(UInt32(kCCOptionPKCS7Padding))
    var numBytesEncrypted :size_t = 0
    let cryptStatus = CCCrypt(operation,
                              algoritm,
                              options,
                              keyData.withUnsafeBytes { (bytes: UnsafePointer<UInt8>) -> UnsafePointer<UInt8> in return bytes},
                              keyLength,
                              iv.withUnsafeBytes { (bytes: UnsafePointer<UInt8>) -> UnsafePointer<UInt8> in return bytes},
                              data.withUnsafeBytes { (bytes: UnsafePointer<UInt8>) -> UnsafePointer<UInt8> in return bytes},
                              data.count,
                              cryptData.mutableBytes, cryptData.length,
                              &numBytesEncrypted)

    if UInt32(cryptStatus) == UInt32(kCCSuccess) {
        cryptData.length = Int(numBytesEncrypted)
        return String(describing: cryptData.base64EncodedString(options: .lineLength64Characters))
    }else{
        return ""
    }
}

标签： swiftcryptographyswift4commoncrypto

解决方案

您的 IV 长度错误。它有 8 个字节长，但 AES 需要 16 个字节的 IV，因此它从内存中读取其他 8 个字节的随机数据。

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