From 71a2030a05f74088f5feb9463d5156c179602a92 Mon Sep 17 00:00:00 2001
From: Yaakov <git@yaakov.dev>
Date: Sun, 26 Sep 2021 14:00:51 +1000
Subject: [PATCH] Add command to generate SAS token for private containers

---
 src/console/Commands/Cdn/StorageSasCommand.cs | 68 +++++++++++++++++++
 src/console/Program.cs                        |  3 +-
 src/console/shamir.csproj                     |  1 +
 3 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 src/console/Commands/Cdn/StorageSasCommand.cs

diff --git a/src/console/Commands/Cdn/StorageSasCommand.cs b/src/console/Commands/Cdn/StorageSasCommand.cs
new file mode 100644
index 0000000..30558c9
--- /dev/null
+++ b/src/console/Commands/Cdn/StorageSasCommand.cs
@@ -0,0 +1,68 @@
+using System;
+using System.Diagnostics;
+using System.Threading.Tasks;
+using Azure.Storage;
+using Azure.Storage.Blobs;
+using Azure.Storage.Sas;
+using CommandLine;
+using Microsoft.Azure.Storage;
+
+namespace Shamir.Console
+{
+    public class StorageSasOptions
+    {
+        [Option("connection-string", Required = false, HelpText = "Azure Storage connection string for the Storage Account backing the CDN.")]
+        public string? ConnectionString { get; set; }
+
+        [Option('h', "host", Required = false, HelpText = "Hostname to generate the SAS token for.")]
+        public string? HostName { get; set; }
+
+        [Option('d', "days", Default = 7, HelpText = "Number of days that the SAS token should remain valid for.")]
+        public int ValidityPeriodDays { get; set; }
+
+        [Value(0, MetaName = "path", Required = true, HelpText = "Path to enumerate, starting with the Azure Storage container name.")]
+        public string? Path { get; set; }
+    }
+
+    public sealed class StorageSasCommand : ParsedArgumentsCommand<StorageSasOptions>
+    {
+        public override string Name => "sas";
+
+        public override string Description => "Generate a SAS token for a file in Storage.";
+
+        public override ValueTask<int> ExecuteAsync(IServiceProvider serviceProvider, StorageSasOptions options)
+        {
+            var connectionString = options.ConnectionString ?? Environment.GetEnvironmentVariable("AZURE_CONNECTION_STRING");
+            var account = CloudStorageAccount.Parse(connectionString);
+            
+            Debug.Assert(options.Path != null, "Path should be set.");
+
+            var delimiterIndex = options.Path.IndexOf('/');
+            var (containerName, path) = delimiterIndex > 0
+                ? (options.Path[..delimiterIndex], options.Path[(delimiterIndex + 1)..])
+                : (options.Path, string.Empty);
+
+            var client = new BlobServiceClient(connectionString);
+
+            var builder = new BlobSasBuilder(BlobSasPermissions.Read, DateTimeOffset.UtcNow.AddDays(options.ValidityPeriodDays));
+            builder.BlobContainerName = containerName;
+            builder.BlobName = path;
+            builder.Protocol = SasProtocol.Https;
+            builder.Resource = "b";
+
+            var key = new StorageSharedKeyCredential(account.Credentials.AccountName, account.Credentials.ExportBase64EncodedKey());
+            var parameters = builder.ToSasQueryParameters(key);
+            var uri = new UriBuilder
+            {
+                Scheme = "https",
+                Host = options.HostName ?? account.BlobStorageUri.PrimaryUri.Host,
+                Path = options.Path,
+                Query = parameters.ToString(),
+            };
+
+            System.Console.WriteLine(uri.Uri.AbsoluteUri);
+
+            return ValueTask.FromResult(0);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/console/Program.cs b/src/console/Program.cs
index 2f5ea58..871caaf 100644
--- a/src/console/Program.cs
+++ b/src/console/Program.cs
@@ -29,7 +29,8 @@ namespace Shamir.Console
                         ImmutableArray<ICommandTree>.Empty,
                         ImmutableArray.Create<ICommand>(
                             new StorageLsCommand(),
-                            new StorageCopyCommand()
+                            new StorageCopyCommand(),
+                            new StorageSasCommand()
                         ))
                 ),
                 ImmutableArray<ICommand>.Empty
diff --git a/src/console/shamir.csproj b/src/console/shamir.csproj
index 4a2c32c..08af8e0 100644
--- a/src/console/shamir.csproj
+++ b/src/console/shamir.csproj
@@ -11,6 +11,7 @@
   <ItemGroup>
     <PackageReference Include="Azure.Storage.Blobs" Version="12.10.0" />
     <PackageReference Include="CommandLineParser" Version="2.8.0" />
+    <PackageReference Include="Microsoft.Azure.Storage.Common" Version="11.2.3" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="5.0.2" />
   </ItemGroup>