从 Mac KeyChain 中检索私钥或公钥

Question

我已经使用必需的属性创建了私钥和公钥对。密钥对生成并保存在 Mac keychain 中。我使用 KeyChain 访问检查了私钥和公钥。但是当我尝试检索它时，它会通过说找不到密钥来抛出错误。

我在下面分享了检索密钥的代码片段

func retrievePrivateKey(_ algorithm: KeyAlgorithm, keySize: Int, tagPrivate: String) throws -> SecKey {
        let getQuery: [String: Any] = [kSecClass as String: kSecClassKey,
                                       kSecAttrApplicationTag as String: tagPrivate,
                                       kSecAttrKeyType as String: algorithm.secKeyAttrType,
                                       kSecReturnRef as String: true]
        var item: CFTypeRef?
        let status = SecItemCopyMatching(getQuery as CFDictionary,&item)
        var error: Unmanaged<CFError>?
        guard status == errSecSuccess else {throw error!.takeRetainedValue() as Error}
        let privateKey = item as! SecKey
        
        return privateKey;
    }

func generateKeyPair(_ algorithm: KeyAlgorithm, keySize: Int, tagPrivate: String, tagPublic: String) {
        let publicKeyParameters: [String : AnyObject] = [
            String(kSecAttrIsPermanent): kCFBooleanTrue,
            String(kSecAttrApplicationTag): tagPublic as AnyObject,
            String(kSecAttrAccessible): kSecAttrAccessibleAfterFirstUnlock,
        ]
        
        let privateKeyParameters: [String: AnyObject] = [
            String(kSecAttrIsPermanent) : kCFBooleanTrue,
            String(kSecAttrApplicationTag) : tagPrivate as AnyObject,
            String(kSecAttrAccessible): kSecAttrAccessibleAfterFirstUnlock,
        ]
        
        let parameters : [String: AnyObject] = [
            String(kSecAttrKeyType): algorithm.secKeyAttrType,
            String(kSecAttrKeySizeInBits): keySize as AnyObject,
            String(kSecReturnRef): kCFBooleanTrue,
            kSecPublicKeyAttrs as String: publicKeyParameters as AnyObject,
            kSecPrivateKeyAttrs as String: privateKeyParameters as AnyObject,
        ]
        
        var error: Unmanaged<CFError>?
        let privateKey = SecKeyCreateRandomKey(parameters as CFDictionary, &error)
        if privateKey == nil {
            print("Error creating keys occured: \(error!.takeRetainedValue() as Error), keys were not created")
            //return(nil,nil)
        }

    }

在 Main 中，我使用以下代码片段调用它们

var handler = Handler()
                let tagPrivate = "com.csr.private.rsa2048sha256"
                let tagPublic  = "com.csr.public.rsa2048sha256"
                let keyAlgorithm = KeyAlgorithm.rsa(signatureType: .sha256)
                let sizeOfKey = keyAlgorithm.availableKeySizes[2]
                handler.generateKeyPair(keyAlgorithm, keySize: sizeOfKey, tagPrivate: tagPrivate, tagPublic: tagPublic)
                handler.retrievePrivateKey(keyAlgorithm, keySize:sizeOfKey, tagPrivate:tagPrivate)