openpgp: Add the SEIPDv2 feature.

3 files changed, 80 insertions, 3 deletions

diff --git a/openpgp/NEWS b/openpgp/NEWS
index 4b24313f..4bb624e3 100644
--- a/openpgp/NEWS
+++ b/openpgp/NEWS
@@ -7,6 +7,7 @@
 ** New functionality
    - types::AEADAlgorithm::GCM
    - types::Features::{clear,set,supports}_seipdv1
+   - types::Features::{clear,set,supports}_seipdv2
 ** Deprecated functionality
    - types::Features::{clear,set,supports}_mdc
 * Changes in 1.16.0
diff --git a/openpgp/src/packet/signature/subpacket.rs b/openpgp/src/packet/signature/subpacket.rs
index 3d324fb0..0c37145f 100644
--- a/openpgp/src/packet/signature/subpacket.rs
+++ b/openpgp/src/packet/signature/subpacket.rs
@@ -7284,7 +7284,7 @@ fn accessors() {
         sig.clone().sign_hash(&mut keypair, hash.clone()).unwrap();
     assert_eq!(sig_.features().unwrap(), feats);
 
-    let feats = Features::empty().set_aead();
+    let feats = Features::empty().set_seipdv2();
     sig = sig.set_features(feats.clone()).unwrap();
     let sig_ =
         sig.clone().sign_hash(&mut keypair, hash.clone()).unwrap();
diff --git a/openpgp/src/types/features.rs b/openpgp/src/types/features.rs
index ebda6821..24f18842 100644
--- a/openpgp/src/types/features.rs
+++ b/openpgp/src/types/features.rs
@@ -8,10 +8,10 @@ use crate::types::Bitfield;
 /// Describes the features supported by an OpenPGP implementation.
 ///
 /// The feature flags are defined in [Section 5.2.3.24 of RFC 4880],
-/// and [Section 5.2.3.25 of RFC 4880bis].
+/// and [Section 5.2.3.32 of draft-ietf-openpgp-crypto-refresh].
 ///
 /// [Section 5.2.3.24 of RFC 4880]: https://tools.ietf.org/html/rfc4880#section-5.2.3.24
-/// [Section 5.2.3.25 of RFC 4880bis]: https://tools.ietf.org/html/draft-ietf-openpgp-rfc4880bis-09#section-5.2.3.25
+/// [Section 5.2.3.32 of draft-ietf-openpgp-crypto-refresh]: https://www.ietf.org/archive/id/draft-ietf-openpgp-crypto-refresh-10.html#features-subpacket
 ///
 /// The feature flags are set by the user's OpenPGP implementation to
 /// signal to any senders what features the implementation supports.
@@ -65,6 +65,11 @@ impl fmt::Debug for Features {
             f.write_str("SEIPDv1")?;
             need_comma = true;
         }
+        if self.supports_seipdv2() {
+            if need_comma { f.write_str(", ")?; }
+            f.write_str("SEIPDv2")?;
+            need_comma = true;
+        }
         if self.supports_aead() {
             if need_comma { f.write_str(", ")?; }
             f.write_str("AEAD")?;
@@ -75,6 +80,7 @@ impl fmt::Debug for Features {
         for i in self.0.iter() {
             match i {
                 FEATURE_FLAG_SEIPDV1 => (),
+                FEATURE_FLAG_SEIPDV2 => (),
                 FEATURE_FLAG_AEAD => (),
                 i => {
                     if need_comma { f.write_str(", ")?; }
@@ -116,6 +122,7 @@ impl Features {
 
         Self::new(&v[..])
             .set_seipdv1()
+            .set_seipdv2()
     }
 
     /// Compares two feature sets for semantic equality.
@@ -307,6 +314,66 @@ impl Features {
         self.clear_seipdv1()
     }
 
+    /// Returns whether the SEIPDv2 feature flag is set.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use sequoia_openpgp as openpgp;
+    /// # use openpgp::Result;
+    /// use openpgp::types::Features;
+    ///
+    /// # fn main() -> Result<()> {
+    /// let f = Features::empty();
+    ///
+    /// assert!(! f.supports_seipdv2());
+    /// # Ok(()) }
+    /// ```
+    pub fn supports_seipdv2(&self) -> bool {
+        self.get(FEATURE_FLAG_SEIPDV2)
+    }
+
+    /// Sets the SEIPDv2 feature flag.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use sequoia_openpgp as openpgp;
+    /// # use openpgp::Result;
+    /// use openpgp::types::Features;
+    ///
+    /// # fn main() -> Result<()> {
+    /// let f = Features::empty().set_seipdv2();
+    ///
+    /// assert!(f.supports_seipdv2());
+    /// # assert!(f.get(3));
+    /// # Ok(()) }
+    /// ```
+    pub fn set_seipdv2(self) -> Self {
+        self.set(FEATURE_FLAG_SEIPDV2)
+    }
+
+    /// Clears the SEIPDv2 feature flag.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use sequoia_openpgp as openpgp;
+    /// # use openpgp::Result;
+    /// use openpgp::types::Features;
+    ///
+    /// # fn main() -> Result<()> {
+    /// let f = Features::new(&[0x8]);
+    /// assert!(f.supports_seipdv2());
+    ///
+    /// let f = f.clear_seipdv2();
+    /// assert!(! f.supports_seipdv2());
+    /// # Ok(()) }
+    /// ```
+    pub fn clear_seipdv2(self) -> Self {
+        self.clear(FEATURE_FLAG_SEIPDV2)
+    }
+
     /// Returns whether the AEAD feature flag is set.
     ///
     /// # Examples
@@ -376,6 +443,10 @@ const FEATURE_FLAG_SEIPDV1: usize = 0;
 /// Encrypted Session Key Packets (packet 3).
 const FEATURE_FLAG_AEAD: usize = 1;
 
+/// Symmetrically Encrypted and Integrity Protected Data packet
+/// version 2.
+const FEATURE_FLAG_SEIPDV2: usize = 3;
+
 #[cfg(test)]
 impl Arbitrary for Features {
     fn arbitrary(g: &mut Gen) -> Self {
@@ -467,6 +538,11 @@ mod tests {
         assert_eq!(a, b);
         assert!(a.normalized_eq(&b));
 
+        let a = Features::empty().set_seipdv2();
+        let b = Features::new(&[ 0x8 ]);
+        assert_eq!(a, b);
+        assert!(a.normalized_eq(&b));
+
         let a = Features::empty().set_aead();
         let b = Features::new(&[ 0x2 ]);
         assert_eq!(a, b);