使用安全飞地iOS AES-GCM加密/解密

Question

我正在iOS上使用secureenclave加密/解密我的机密密钥，并将其保存在userpreferences中。已成功设置并加密数据。但是每当我试图解密数据时，它都会给我以下错误：

Error domain=nsosstatuserrordomain code=-50\“ecies：未能到aes-gcm解密数据\”userinfo={nsdescription=ecies：未能到aes-gcm解密数据}

此外，在10.3中，使用KseckeyAlgorithmeCiesEncryptionCofactorx963SHA256AESGCM解密大量数据时出现了一个问题。我为它提交了一份错误报告，它在iOS11中得到了修复。：）

但是我用的是iOS12.2的iPhone8，还是有个问题。

这两个问题，这里和这里提供了一些细节，但我无法破译。另外，我用的是Swift 4。

func generateKeyPair(accessControl: SecAccessControl) throws -> (`public`: SecureEnclaveKeyReference, `private`: SecureEnclaveKeyReference) {

    let publicKeyParameters: [String: AnyObject] = [
        kSecAttrIsPermanent as String: false as AnyObject,
        kSecAttrApplicationTag as String: "com.xxx.xxx" as AnyObject,
        kSecAttrLabel as String: "PublicKey" as AnyObject
    ]

    let privateKeyParameters: [String: AnyObject] = [
        (kSecAttrCanDecrypt as CFString) as String: true as CFBoolean,
        kSecAttrIsPermanent as String: true as AnyObject,
        kSecAttrAccessControl as String: accessControl,
        kSecAttrApplicationTag as String: "com.xxx.xxx" as AnyObject,
        kSecAttrLabel as String: "PrivateKey" as AnyObject
    ]

    let parameters: [String: AnyObject] = [
        kSecAttrKeyType as String: kSecAttrKeyTypeEC,
        kSecAttrKeySizeInBits as String: 256 as AnyObject,
        kSecAttrTokenID as String: kSecAttrTokenIDSecureEnclave,
        kSecPublicKeyAttrs as String: publicKeyParameters as AnyObject,
        kSecPrivateKeyAttrs as String: privateKeyParameters as AnyObject
    ]



    var publicKey, privateKey: SecKey?
    let status = SecKeyGeneratePair(parameters as CFDictionary, &publicKey, &privateKey)

    print("Result = \(status) - Public Key = \(publicKey) - Private Key = \(privateKey)")


    guard status == errSecSuccess else {

        throw SecureEnclaveHelperError(message: "Could not generate keypair", osStatus: status)
    }


    return (public: SecureEnclaveKeyReference(publicKey!), private: SecureEnclaveKeyReference(privateKey!))

}

@available(iOS 10.3, *)
func encrypt(_ digest: Data, publicKey: SecureEnclaveKeyReference) throws -> Data {

    var error : Unmanaged<CFError>?

    let result = SecKeyCreateEncryptedData(publicKey.underlying, SecKeyAlgorithm.eciesEncryptionStandardX963SHA256AESGCM, digest as CFData, &error)

    if result == nil {

        throw SecureEnclaveHelperError(message: "\(error)", osStatus: 0)
    }

    return result as! Data
}

@available(iOS 10.3, *)
func decrypt(_ digest: Data, privateKey: SecureEnclaveKeyReference) throws -> Data {

    var error : Unmanaged<CFError>?

    let result = SecKeyCreateDecryptedData(privateKey.underlying, SecKeyAlgorithm.eciesEncryptionStandardX963SHA256AESGCM, digest as CFData, &error)

    if result == nil {

        throw SecureEnclaveHelperError(message: "\(error)", osStatus: 0)
    }

    return result as! Data
}

任何帮助都是非常感谢的。谢了。

Answer 1

我得到了同样的错误，并发现我生成了两个不同的密钥对，其中我用一个公钥加密了数据，但用另一个错误的私钥进行了解密。因此，请确保解密操作使用与加密中使用的公钥相对应的正确私钥。