Secret key for messsage not found

[knaidoo33]

Hi, I am trying to decrypt a Stream using an Azure function app in which the function is http triggered and the data to be decrypted is passed into req.body.
The passphrase and key are stored in a vault, I have verified that they work using gpg4win, and that the app can access them and they print out correctly.
Can you help me figure out why I am seeing the error "Secret Key for message cannot be found" when the key, passphrase, and data are being passed correctly?

using System.IO;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using PgpCore;
using System.Threading.Tasks;
using Microsoft.Azure.KeyVault.Models;
using System.Net.Http;
using Microsoft.Azure.Services.AppAuthentication;
using Microsoft.Azure.KeyVault;
using System;
using System.Text;
using System.Collections.Concurrent;
using Microsoft.Extensions.Logging;

namespace AzureFunctionsPGPDecrypt
{
public static class PGPDecrypt
{
private static readonly HttpClient client = new HttpClient();
private static ConcurrentDictionary<string, string> secrects = new ConcurrentDictionary<string, string>();

    [FunctionName(nameof(PGPDecrypt))]
    public static IActionResult Run(
        [HttpTrigger(AuthorizationLevel.Function, "post", Route = null)]
    HttpRequest req, ILogger log)
    {
        log.LogInformation($"C# HTTP trigger function {nameof(PGPDecrypt)} processed a request.");

    

        string privateKey =  Environment.GetEnvironmentVariable("secretkey", EnvironmentVariableTarget.Process);
        string passPhrase=  Environment.GetEnvironmentVariable("secretphrase", EnvironmentVariableTarget.Process);

        log.LogInformation($"SecretKey: {privateKey}");
        log.LogInformation($"SecretPassPhrase: {passPhrase}");

        if (privateKey == null)
        {
            return new BadRequestObjectResult("Please pass a private key secret identifier on the query string");
        }


        Stream outputStream = new MemoryStream();
        Stream privateKeyStream = GenerateStreamFromString(privateKey);

        var length = privateKeyStream.Length;
        var length2 = req.Body.Length;

        log.LogInformation($"Length private key stream: {length}");
        log.LogInformation($"Length body: {length2}");

//verifying that the streams were not empty

        using (PGP pgp = new PGP())
        {
            

            using (Stream inputStream = req.Body)
            using(outputStream)
            using (privateKeyStream)
            {
            
                pgp.DecryptStreamAsync(inputStream, outputStream, privateKeyStream, passPhrase);
                
                return new OkObjectResult(outputStream);
            }
        }

    }

    

    private static Stream GenerateStreamFromString(string s)
    {
        MemoryStream stream = new MemoryStream();
        StreamWriter writer = new StreamWriter(stream);
        writer.Write(s);
        writer.Flush();
        stream.Position = 0;
        return stream;
    }
}

}

[knaidoo33]

I figured it out - I needed to find the beginning of the string

inputStream.Seek(0, SeekOrigin.Begin);
privateKeyStream.Seek(0, SeekOrigin.Begin);