How to encrypt xml file in Azure Logicapp? - azure

Question

I have a below requirement
1. XML file need to read from SharePoint and copy into Azure Blob.
2. Need to use Logic app to read the file from share point and copy into Azure Blob.
3. Before copy into Azure Blob need to encrypt the data in Logic app.
Please let me know if any suggestions.

Answer 1

As far as I know there is nothing out the box to help here. You will need to write an Azure Function (or a REST endpoint) to perform the encryption and call that from your Logic App.
There are many examples of such a function, you can find one for PGP here. The core function is copied below and Microsoft's guidance on calling functions from Logic Apps is here.
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.AspNetCore.Http.Internal;
using Microsoft.Extensions.Logging;
namespace AzureFunctionsPGPEncrypt
{
public static class PGPEncrypt
{
private static readonly HttpClient client = new HttpClient();
private static ConcurrentDictionary<string, string> secrets = new ConcurrentDictionary<string, string>();
[FunctionName(nameof(PGPEncrypt))]
public static async Task<IActionResult> RunAsync(
[HttpTrigger(AuthorizationLevel.Function, "post", Route = null)]
HttpRequest req, ILogger log)
{
log.LogInformation($"C# HTTP trigger function {nameof(PGPEncrypt)} processed a request.");
string publicKeyBase64 = req.Query["public-key"];
string publicKeyEnvironmentVariable = req.Query["public-key-environment-variable"];
string publicKeySecretId = req.Query["public-key-secret-id"];
if (publicKeyBase64 == null && publicKeyEnvironmentVariable == null && publicKeySecretId == null)
{
return new BadRequestObjectResult("Please pass a base64 encoded public key, an environment variable name, or a key vault secret identifier on the query string");
}
if (publicKeyBase64 == null && publicKeyEnvironmentVariable != null)
{
publicKeyBase64 = Environment.GetEnvironmentVariable(publicKeyEnvironmentVariable);
}
if (publicKeyBase64 == null && publicKeySecretId != null)
{
try
{
publicKeyBase64 = await GetPublicKeyAsync(publicKeySecretId);
}
catch (KeyVaultErrorException e) when (e.Body.Error.Code == "SecretNotFound")
{
return new NotFoundResult();
}
catch (KeyVaultErrorException e) when (e.Body.Error.Code == "Forbidden")
{
return new UnauthorizedResult();
}
}
byte[] data = Convert.FromBase64String(publicKeyBase64);
string publicKey = Encoding.UTF8.GetString(data);
req.EnableRewind(); //Make RequestBody Stream seekable
Stream encryptedData = await EncryptAsync(req.Body, publicKey);
return new OkObjectResult(encryptedData);
}
private static async Task<string> GetPublicKeyAsync(string secretIdentifier)
{
if (!secrets.ContainsKey(secretIdentifier))
{
var azureServiceTokenProvider = new AzureServiceTokenProvider();
var authenticationCallback = new KeyVaultClient.AuthenticationCallback(azureServiceTokenProvider.KeyVaultTokenCallback);
var kvClient = new KeyVaultClient(authenticationCallback, client);
SecretBundle secretBundle = await kvClient.GetSecretAsync(secretIdentifier);
secrets[secretIdentifier] = secretBundle.Value;
}
return secrets[secretIdentifier];
}
private static async Task<Stream> EncryptAsync(Stream inputStream, string publicKey)
{
using (PGP pgp = new PGP())
{
Stream outputStream = new MemoryStream();
using (inputStream)
using (Stream publicKeyStream = GenerateStreamFromString(publicKey))
{
await pgp.EncryptStreamAsync(inputStream, outputStream, publicKeyStream, true, true);
outputStream.Seek(0, SeekOrigin.Begin);
return 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;
}
}
}