enable setting multiple SAS permissions at once (#432)

Author: bmc-msft

sdk/storage/examples/copy_blob.rs

@@ -61,7 +61,10 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
             .with_resource_type(SasResourceType::Object)
             .with_start(now)
             .with_expiry(later)
-            .with_permissions(SasPermissions::Read)
+            .with_permissions(SasPermissions {
+                read: true,
+                ..Default::default()
+            })
             .with_protocol(SasProtocol::HttpHttps)
             .finalize();
         println!("token: '{}'", sas.token());

sdk/storage/examples/shared_access_signature.rs

@@ -40,7 +40,10 @@ fn code() -> Result<(), Box<dyn Error + Sync + Send>> {
         .with_resource_type(SasResourceType::Object)
         .with_start(now)
         .with_expiry(later)
-        .with_permissions(SasPermissions::Read)
+        .with_permissions(SasPermissions {
+            read: true,
+            ..Default::default()
+        })
         .with_protocol(SasProtocol::HttpHttps)
         .finalize();
     println!("token: '{}'", sas.token());

sdk/storage/src/core/shared_access_signature.rs

@@ -99,30 +99,49 @@ impl fmt::Display for SasResourceType {
 }
 
 /// Indicate which operations a key_client may perform on the resource ([Azure documentation](https://docs.microsoft.com/rest/api/storageservices/create-service-sas#specifying-permissions)).
-#[derive(Copy, Clone)]
-pub enum SasPermissions {
-    Read,
-    Write,
-    Delete,
-    List,
-    Add,
-    Create,
-    Update,
-    Process,
+#[derive(Copy, Clone, Default)]
+pub struct SasPermissions {
+    pub read: bool,
+    pub write: bool,
+    pub delete: bool,
+    pub list: bool,
+    pub add: bool,
+    pub create: bool,
+    pub update: bool,
+    pub process: bool,
 }
 
 impl fmt::Display for SasPermissions {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match *self {
-            SasPermissions::Read => write!(f, "r"),
-            SasPermissions::Write => write!(f, "w"),
-            SasPermissions::Delete => write!(f, "d"),
-            SasPermissions::List => write!(f, "l"),
-            SasPermissions::Add => write!(f, "a"),
-            SasPermissions::Create => write!(f, "c"),
-            SasPermissions::Update => write!(f, "u"),
-            SasPermissions::Process => write!(f, "p"),
+        // NOTE: order *must* be `racwdxltmeop` per documentation:
+        // https://docs.microsoft.com/en-us/rest/api/storageservices/create-service-sas#specifying-permissions
+
+        if self.read {
+            write!(f, "r")?;
+        }
+        if self.add {
+            write!(f, "a")?;
+        }
+        if self.create {
+            write!(f, "c")?;
+        }
+        if self.write {
+            write!(f, "w")?;
         }
+        if self.delete {
+            write!(f, "d")?;
+        }
+        if self.list {
+            write!(f, "l")?;
+        }
+        if self.update {
+            write!(f, "u")?;
+        }
+        if self.process {
+            write!(f, "p")?;
+        }
+
+        Ok(())
     }
 }