feat: CTAP/FIDO cert

src/fido.rs

@@ -59,4 +59,27 @@ pub fn start_status_updater() -> Sender<StatusUpdate> {
         }
     });
     status_tx
+}
+
+pub fn to_pem(bs: &[u8], sub: &str, w: usize) -> String {
+    let mut s = String::with_capacity(bs.len() * 2);
+    s.push_str(&format!("-----BEGIN {}-----", sub));
+    let b64 = base64::encode(bs).chars().collect::<Vec<char>>();
+    let mut b64 = b64.as_slice();
+    while b64.len() > 0 {
+        s.push('\n');
+        if b64.len() >= w {
+            for i in 0..w {
+                s.push(b64[i]);
+            }
+            b64 = &b64[w..];
+        } else {
+            for c in b64 {
+                s.push(*c);
+            }
+            b64 = &[];
+        }
+    }
+    s.push_str(&format!("\n-----END {}-----", sub));
+    s
 }