Swift 加载本地证书并提取公钥

// 使用证书文件路径加载证书
        let certificateFilePath = Bundle.main.path(forResource: "cert", ofType: "cer")!
        let certificateData = try! Data(contentsOf: URL(fileURLWithPath: certificateFilePath))
        let certificate = SecCertificateCreateWithData(nil, certificateData as CFData)

        // 提取证书公钥
        if let publicKey = extractPublicKey(from: certificate!) {
            // 公钥提取成功，可以使用
            print("提取公钥成功")
            print(publicKey)
            
        } else {
            // 公钥提取失败，处理错误
            print("提取公钥失败")
        }

=====================
// 导出公钥
    func extractPublicKey(from certificate: SecCertificate) -> SecKey? {
        var key: SecKey?
        let policy = SecPolicyCreateBasicX509()
        var trust: SecTrust?
        let status = SecTrustCreateWithCertificates(certificate, policy, &trust)
        guard status == errSecSuccess, let serverTrust = trust else {
            return nil
        }
        let serverPublicKey = SecTrustCopyPublicKey(serverTrust)
        if let publicKey = serverPublicKey {
            key = publicKey
        }
        return key
    }