functions1.cs

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using Azure.Storage.Blobs;
using Azure.Identity;
using Azure.Storage.Blobs.Models;
using Azure.Storage.Sas;

namespace sastest
{
    public static class Function1
    {
        [FunctionName("Function1")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            var accountName = "xxxx";
            var containerName = "test";
            var blobName = "test.txt";

            string blobEndpoint = string.Format("https://{0}.blob.core.windows.net", accountName);

            var blobClient = new BlobServiceClient(new Uri(blobEndpoint), new DefaultAzureCredential());
            UserDelegationKey key = await blobClient.GetUserDelegationKeyAsync(DateTimeOffset.UtcNow.AddMinutes(-1),
                                                                   DateTimeOffset.UtcNow.AddDays(7));

            log.LogInformation("User delegation key properties:");
            log.LogInformation("Key signed start: {0}", key.SignedStart);
            log.LogInformation("Key signed expiry: {0}", key.SignedExpiry);
            log.LogInformation("Key signed object ID: {0}", key.SignedOid);
            log.LogInformation("Key signed tenant ID: {0}", key.SignedTid);
            log.LogInformation("Key signed service: {0}", key.SignedService);
            log.LogInformation("Key signed version: {0}", key.SignedVersion);

            BlobSasBuilder builder = new BlobSasBuilder()
            {
                ContainerName = containerName,
                BlobName = blobName,
                Permissions = "r",          // read
                Resource = "b",             // blob
                StartTime = DateTimeOffset.UtcNow.AddMinutes(-1),
                ExpiryTime = DateTimeOffset.UtcNow.AddMinutes(10),
                Version = key.SignedVersion
            };

            string sasToken = builder.ToSasQueryParameters(key, accountName).ToString();

            UriBuilder fullUri = new UriBuilder()
            {
                Scheme = "https",
                Host = string.Format("{0}.blob.core.windows.net", accountName),
                Path = string.Format("{0}/{1}", containerName, blobName),
                Query = sasToken
            };

            log.LogInformation("URL: {0}", fullUri);
            return (ActionResult)new OkObjectResult($"url: {fullUri}");
        }
    }
}