ios - 如何使用 ECDH 加密快速创建 64 字节公钥和 32 字节私钥？

Question

我必须保护我的锁免受 MITM（即中间人攻击）。为此，我必须整合ECDH encryption。我没有这方面的知识。请帮助我如何创建64 bytes public和32 byte private键入。下面是我正在尝试的代码

var publicKeySec, privateKeySec: SecKey?
let keyattribute = [
    kSecAttrKeyType as String: kSecAttrKeyTypeEC,
    kSecAttrKeySizeInBits as String : 256
    ] as CFDictionary

SecKeyGeneratePair(keyattribute, &publicKeySec, &privateKeySec)


var error:Unmanaged<CFError>?
if let publicCfdata = SecKeyCopyExternalRepresentation(publicKeySec!, &error) {
    let data:Data = publicCfdata as Data
    print(data)
    let b64Key = data.base64EncodedString()
    print(b64Key)
}

if let privateCfdata = SecKeyCopyExternalRepresentation(privateKeySec!, &error) {
    let data:Data = privateCfdata as Data
    print(data)
    let b64Key = data.base64EncodedString()
    print(b64Key)
}

请帮我。提前致谢。