1 files changed, 92 insertions, 0 deletions
diff --git a/openpgp/src/packet/padding.rs b/openpgp/src/packet/padding.rs
new file mode 100644
index 00000000..6b7fab5f
--- /dev/null
+++ b/openpgp/src/packet/padding.rs
@@ -0,0 +1,92 @@
+use std::fmt;
+
+#[cfg(test)]
+use quickcheck::{Arbitrary, Gen};
+
+use crate::packet;
+use crate::Packet;
+
+/// Holds a Padding packet.
+///
+/// Padding packets are used to obscure the size of cryptographic
+/// artifacts.
+///
+/// See [Section 5.15 of RFC XXX] for details.
+///
+///   [Section 5.15 of RFC XXX]: https://openpgp-wg.gitlab.io/rfc4880bis/#name-padding-packet-tag-21
+// IMPORTANT: If you add fields to this struct, you need to explicitly
+// IMPORTANT: implement PartialEq, Eq, and Hash.
+#[derive(Clone, PartialEq, Eq, Hash)]
+pub struct Padding {
+    pub(crate) common: packet::Common,
+    value: Vec<u8>,
+}
+
+assert_send_and_sync!(Padding);
+
+impl From<Vec<u8>> for Padding {
+    fn from(u: Vec<u8>) -> Self {
+        Padding {
+            common: Default::default(),
+            value: u,
+        }
+    }
+}
+
+impl fmt::Display for Padding {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let padding = String::from_utf8_lossy(&self.value[..]);
+        write!(f, "{}", padding)
+    }
+}
+
+impl fmt::Debug for Padding {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Padding {{ {} bytes }}", self.value.len())
+    }
+}
+
+impl Padding {
+    /// Creates a new Padding packet of the given size.
+    ///
+    /// Note that this is the net size, packet framing (CTB and packet
+    /// length) will come on top.
+    pub fn new(size: usize) -> Padding {
+        let mut v = vec![0; size];
+        crate::crypto::random(&mut v);
+        v.into()
+    }
+
+    /// Gets the padding packet's value.
+    pub(crate) fn value(&self) -> &[u8] {
+        self.value.as_slice()
+    }
+}
+
+impl From<Padding> for Packet {
+    fn from(s: Padding) -> Self {
+        Packet::Padding(s)
+    }
+}
+
+#[cfg(test)]
+impl Arbitrary for Padding {
+    fn arbitrary(g: &mut Gen) -> Self {
+        Vec::<u8>::arbitrary(g).into()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::parse::Parse;
+    use crate::serialize::MarshalInto;
+
+    quickcheck! {
+        fn roundtrip(p: Padding) -> bool {
+            let q = Padding::from_bytes(&p.to_vec().unwrap()).unwrap();
+            assert_eq!(p, q);
+            true
+        }
+    }
+}