Add an accessor for signature version

Signed-off-by: Daniel Alley <dalley@redhat.com>

Author: dralley

NEXT.md

@@ -6,7 +6,7 @@ New:
   - Added `Sig.issuer_fingerprint`, `Sig.issuer_key_id`, `Sig.signers_user_id`, and `Sig.expiration` [#60]
   - Added docstrings to the `Sig` API [#60]
   - Added `PacketPile` and `Packet` for low-level reading of individual packet fields [#61]
-  - Added `Sig.signature_type`, `Sig.hash_algorithm`, `Sig.key_algorithm`, and `Sig.key_validity_period` [#61]
+  - Added `Sig.signature_type`, `Sig.hash_algorithm`, `Sig.key_algorithm`, `Sig.key_validity_period`, and `Sig.version` [#61]
   - Added `SignatureType`, `PublicKeyAlgorithm`, `HashAlgorithm`, `DataFormat`, `Tag` and `KeyFlags` as returned types [#61]
   - Added Sequoia's `armor::Writer` for applying Ascii Armor to data, via the `armor()` function and `ArmorKind` type [#61]
 

src/packet.rs

@@ -210,6 +210,17 @@ impl PyPacket {
 
     // -- Signature packet accessors --
 
+    /// The version of a signature packet (e.g. 4 or 6).
+    ///
+    /// Returns `None` for non-Signature packets.
+    #[getter]
+    pub fn signature_version(&self) -> Option<u8> {
+        match &self.packet {
+            Packet::Signature(sig) => Some(sig.version()),
+            _ => None,
+        }
+    }
+
     /// The signature type (e.g. `SignatureType.SubkeyBinding`).
     ///
     /// Returns `None` for non-Signature packets.

src/signature.rs

@@ -125,6 +125,12 @@ impl Sig {
         self.sig.signature_expiration_time().map(Into::into)
     }
 
+    /// The version of this signature packet (e.g. 4 or 6).
+    #[getter]
+    pub fn version(&self) -> u8 {
+        self.sig.version()
+    }
+
     /// The signature type (e.g. `SignatureType.SubkeyBinding`).
     #[getter]
     pub fn signature_type(&self) -> PyResult<SignatureType> {