Add ability to set permissions when retrieving SAS-based URL

pofider · Sep 14, 2015 · ce50208 · ce50208
1 parent 3c1e1b2
commit ce50208
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Showing 5 changed files with 35 additions and 6 deletions.
diff --git a/AzureBlobFileSystem/AzureBlobFileSystem.csproj b/AzureBlobFileSystem/AzureBlobFileSystem.csproj
@@ -79,6 +79,7 @@
     <Compile Include="IStorageProvider.cs" />
     <Compile Include="PathValidation.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="SasPermissionFlags.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />

diff --git a/AzureBlobFileSystem/AzureBlobStorageProvider.cs b/AzureBlobFileSystem/AzureBlobStorageProvider.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Xml.Linq;
@@ -420,12 +421,15 @@ public string GetFileType()
                 return Path.GetExtension(GetPath());
             }
 
-            public string GetSharedAccessPath(DateTimeOffset? expiration = null)
+            public string GetSharedAccessPath(DateTimeOffset? expiration = null, SasPermissionFlags permissions = SasPermissionFlags.Read)
             {
-                return _blob.Uri.AbsoluteUri + _blob.GetSharedAccessSignature(new SharedAccessBlobPolicy()
+                var sasToken = _blob.GetSharedAccessSignature(new SharedAccessBlobPolicy()
                 {
-                    SharedAccessExpiryTime = expiration ?? _azureFileSystem.DefaultSharedAccessExpiration
-                }, "default");
+                    SharedAccessExpiryTime = expiration ?? _azureFileSystem.DefaultSharedAccessExpiration,
+                    Permissions = GetSharedAccessBlobPermissions(permissions)
+                });
+
+                return string.Format(CultureInfo.InvariantCulture, "{0}{1}", _blob.Uri, sasToken);
             }
 
             public Stream OpenRead()
@@ -448,6 +452,11 @@ public Stream CreateFile()
 
                 return OpenWrite();
             }
+
+            private static SharedAccessBlobPermissions GetSharedAccessBlobPermissions(SasPermissionFlags flags)
+            {
+                return (SharedAccessBlobPermissions)flags;
+            }
         }
 
         private class AzureBlobFolderStorage : IStorageFolder

diff --git a/AzureBlobFileSystem/FileSystemStorageProvider.cs b/AzureBlobFileSystem/FileSystemStorageProvider.cs
@@ -361,7 +361,7 @@ public string GetFileType()
                 return _fileInfo.Extension;
             }
 
-            public string GetSharedAccessPath(DateTimeOffset? expiration = null)
+            public string GetSharedAccessPath(DateTimeOffset? expiration = null, SasPermissionFlags permissions = SasPermissionFlags.Read)
             {
                 return _path;
             }

diff --git a/AzureBlobFileSystem/IStorageFile.cs b/AzureBlobFileSystem/IStorageFile.cs
@@ -10,7 +10,7 @@ public interface IStorageFile
         long GetSize();
         DateTime GetLastUpdated();
         string GetFileType();
-        string GetSharedAccessPath(DateTimeOffset? expiration = null);
+        string GetSharedAccessPath(DateTimeOffset? expiration = null, SasPermissionFlags permissions = SasPermissionFlags.Read);
 
         /// <summary>
         /// Creates a stream for reading from the file.

diff --git a/AzureBlobFileSystem/SasPermissionFlags.cs b/AzureBlobFileSystem/SasPermissionFlags.cs
@@ -0,0 +1,19 @@
+using System;
+using Microsoft.WindowsAzure.Storage.Blob;
+
+namespace AzureBlobFileSystem
+{
+    /// <summary>
+    /// Specifies the set of possible permissions for a shared access policy.
+    /// This mirrors the flags available in the Azure Storage Client Library
+    /// </summary>
+    [Flags]
+    public enum SasPermissionFlags
+    {
+        None = 0,
+        Read = 1,
+        Write = 2,
+        Delete = 4,
+        List = 8,
+    }
+}