obfuscate auth header (#254)

crates/common/src/pii.rs

@@ -0,0 +1,44 @@
+pub fn obfuscate_auth_header(headers: &mut [(String, String)]) -> &[(String, String)] {
+    headers.iter_mut().for_each(|(key, value)| {
+        if key.to_lowercase() == "authorization" {
+            if value.starts_with("Bearer ") {
+                *value = "Bearer ***".to_string();
+            } else {
+                *value = "***".to_string();
+            }
+        }
+    });
+
+    headers
+}
+
+#[cfg(test)]
+mod test {
+    use crate::pii::obfuscate_auth_header;
+
+    #[test]
+    pub fn test_obfuscate_auth_header() {
+        let mut headers = vec![("Authorization".to_string(), "Bearer 1234".to_string())];
+        obfuscate_auth_header(&mut headers);
+        assert_eq!(
+            headers,
+            vec![("Authorization".to_string(), "Bearer ***".to_string())]
+        );
+    }
+
+    #[test]
+    pub fn test_obfuscate_no_auth_header_found() {
+        let mut headers = vec![
+            (":path".to_string(), "/healthz".to_string()),
+            (":method".to_string(), "POST".to_string()),
+        ];
+        obfuscate_auth_header(&mut headers);
+        assert_eq!(
+            headers,
+            vec![
+                (":path".to_string(), "/healthz".to_string()),
+                (":method".to_string(), "POST".to_string()),
+            ]
+        );
+    }
+}