C＃ - 使用PGP加密和解密音频文件（错误：InputStream必须寻求）

Question

上下文：在Azure存储中加密和解密音频文件（.WAV）。 问题：InputStream必须在加密时（加密时）。

我不是C＃开发人员:)

谢谢您的帮助，

以下是我正在使用的代码：

 static async Task Main()
    {
        
        string connectionString = Environment.GetEnvironmentVariable("AZURE_STORAGE_CONNECTION_STRING");
        ////Create a unique name for the container
        string containerName = "audioinput";
        string filename = "abc.wav";

        //// Create a BlobServiceClient object which will be used to create a container client
        BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);
        BlobContainerClient sourcecontainer = blobServiceClient.GetBlobContainerClient(containerName);
        BlobClient blobClient = sourcecontainer.GetBlobClient(filename);

        if (sourcecontainer.Exists())
        {

            var sourceStream = new MemoryStream();
            
                //Download blob to MemoryStream
                await blobClient.DownloadToAsync(sourceStream);
                sourceStream.Position = 0;
                
                //OutputStream
                await using var outputStream = new MemoryStream();
                
                //Get encryptionkeys
                EncryptionKeys encryptionKeys;
                using (Stream publicKeyStream = new FileStream(@"...\public.asc", FileMode.Open))
                    encryptionKeys = new EncryptionKeys(publicKeyStream);

                PGP pgp = new PGP(encryptionKeys);

            await pgp.EncryptStreamAsync(sourceStream, outputStream);
            

        }
        else
        {
            Console.WriteLine("container doesn't exist");
        }

    }