server/rest.rs: verify auth cookie

src/tools.rs

@@ -416,3 +416,27 @@ pub fn assert_if_modified(digest1: &str, digest2: &str) -> Result<(), Error> {
     }
     Ok(())
 }
+
+/// Extract authentication cookie from cookie header.
+/// We assume cookie_name is already url encoded.
+pub fn extract_auth_cookie(cookie: &str, cookie_name: &str) -> Option<String> {
+
+    for pair in cookie.split(';') {
+
+        let (name, value) = match pair.find('=') {
+            Some(i) => (pair[..i].trim(), pair[(i + 1)..].trim()),
+            None => return None, // Cookie format error
+        };
+
+        if name == cookie_name {
+            use url::percent_encoding::percent_decode;
+            if let Ok(value) = percent_decode(value.as_bytes()).decode_utf8() {
+                return Some(value.into());
+            } else {
+                return None; // Cookie format error
+            }
+        }
+    }
+
+    None
+}