openpgp: Introduce trait Amalgamation.

  - First, we implement it for ValidComponentAmalgamation.

8 files changed, 68 insertions, 26 deletions

diff --git a/openpgp/src/autocrypt.rs b/openpgp/src/autocrypt.rs
index b66d9770..b308e29d 100644
--- a/openpgp/src/autocrypt.rs
+++ b/openpgp/src/autocrypt.rs
@@ -26,6 +26,7 @@ use crate::Result;
 use crate::Packet;
 use crate::packet::SKESK;
 use crate::Cert;
+use crate::cert::components::Amalgamation;
 use crate::parse::{
     Parse,
     PacketParserResult, PacketParser,
diff --git a/openpgp/src/cert/amalgamation.rs b/openpgp/src/cert/amalgamation.rs
index 037f4cb1..ea07031f 100644
--- a/openpgp/src/cert/amalgamation.rs
+++ b/openpgp/src/cert/amalgamation.rs
@@ -189,7 +189,11 @@ impl<'a, C> ValidComponentAmalgamation<'a, C>
     }
 }
 
-impl<'a, C> ValidComponentAmalgamation<'a, C> {
+/// Represents a component under a given policy.
+pub trait Amalgamation<'a> {
+    /// Returns the certificate that the component came from.
+    fn cert(&self) -> &'a Cert;
+
     /// Returns the amalgamation's reference time.
     ///
     /// For queries that are with respect to a point in time, this
@@ -197,48 +201,75 @@ impl<'a, C> ValidComponentAmalgamation<'a, C> {
     /// created at `t_c` and expires at `t_e`, then
     /// `ValidComponentAmalgamation::alive` will return true if the reference
     /// time is greater than or equal to `t_c` and less than `t_e`.
-    pub fn time(&self) -> SystemTime {
-        self.time
-    }
+    fn time(&self) -> SystemTime;
 
     /// Changes the amalgamation's policy.
     ///
     /// If `time` is `None`, the current time is used.
-    pub fn policy<T>(self, time: T) -> Result<Self>
-        where T: Into<Option<time::SystemTime>>
-    {
-        let time = time.into().unwrap_or_else(SystemTime::now);
-        self.a.policy(time)
-    }
+    fn policy<T>(self, time: T) -> Result<Self>
+        where Self: Sized, T: Into<Option<time::SystemTime>>;
 
-    /// Returns the component's binding signature as of the reference time,
-    /// if any.
-    pub fn binding_signature(&self) -> &'a Signature {
-        self.binding_signature
-    }
+    /// Returns the component's binding signature as of the reference time.
+    fn binding_signature(&self) -> &'a Signature;
 
     /// Returns the component's revocation status as of the amalgamation's
     /// reference time.
     ///
     /// Note: this does not return whether the certificate is valid.
-    pub fn revoked(&self) -> RevocationStatus<'a> {
-        self.binding._revoked(false, Some(self.binding_signature), self.time)
-    }
+    fn revoked(&self) -> RevocationStatus<'a>;
 
     /// Returns the certificate's revocation status as of the
     /// amalgamtion's reference time.
-    pub fn cert_revoked(&self) -> RevocationStatus<'a> {
+    fn cert_revoked(&self) -> RevocationStatus<'a> {
         self.cert().revoked(self.time())
     }
 
     /// Returns whether the certificateis alive as of the
     /// amalgamtion's reference time.
-    pub fn cert_alive(&self) -> Result<()> {
+    fn cert_alive(&self) -> Result<()> {
         self.cert().alive(self.time())
     }
+}
 
-    /// Returns this component's component binding.
-    pub fn binding(&self) -> &'a ComponentBinding<C> {
-        &self.binding
+impl<'a, C> Amalgamation<'a> for ValidComponentAmalgamation<'a, C> {
+    // NOTE: No docstring, because ComponentAmalgamation has the same method.
+    // Returns the certificate that the component came from.
+    fn cert(&self) -> &'a Cert {
+        self.cert
+    }
+
+    /// Returns the amalgamation's reference time.
+    ///
+    /// For queries that are with respect to a point in time, this
+    /// determines that point in time.  For instance, if a component is
+    /// created at `t_c` and expires at `t_e`, then
+    /// `ValidComponentAmalgamation::alive` will return true if the reference
+    /// time is greater than or equal to `t_c` and less than `t_e`.
+    fn time(&self) -> SystemTime {
+        self.time
+    }
+
+    /// Changes the amalgamation's policy.
+    ///
+    /// If `time` is `None`, the current time is used.
+    fn policy<T>(self, time: T) -> Result<Self>
+        where T: Into<Option<time::SystemTime>>
+    {
+        let time = time.into().unwrap_or_else(SystemTime::now);
+        self.a.policy(time)
+    }
+
+    /// Returns the component's binding signature as of the reference time.
+    fn binding_signature(&self) -> &'a Signature {
+        self.binding_signature
+    }
+
+    /// Returns the component's revocation status as of the amalgamation's
+    /// reference time.
+    ///
+    /// Note: this does not return whether the certificate is valid.
+    fn revoked(&self) -> RevocationStatus<'a> {
+        self.binding._revoked(false, Some(self.binding_signature), self.time)
     }
 }
+
diff --git a/openpgp/src/cert/builder.rs b/openpgp/src/cert/builder.rs
index b1152517..2df4606d 100644
--- a/openpgp/src/cert/builder.rs
+++ b/openpgp/src/cert/builder.rs
@@ -463,6 +463,7 @@ impl CertBuilder {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::cert::components::Amalgamation;
     use crate::packet::signature::subpacket::{SubpacketTag, SubpacketValue};
     use crate::types::PublicKeyAlgorithm;
 
diff --git a/openpgp/src/cert/component_iter.rs b/openpgp/src/cert/component_iter.rs
index 05d4293f..9f7b015e 100644
--- a/openpgp/src/cert/component_iter.rs
+++ b/openpgp/src/cert/component_iter.rs
@@ -8,8 +8,7 @@ use crate::{
         components::{
             ComponentBinding,
             ComponentBindingIter,
-        },
-        amalgamation::{
+            Amalgamation,
             ComponentAmalgamation,
             ValidComponentAmalgamation,
         },
@@ -177,6 +176,7 @@ impl<'a, C> ValidComponentIter<'a, C> {
     /// # use openpgp::Result;
     /// # use openpgp::cert::CertBuilder;
     /// use openpgp::RevocationStatus;
+    /// use openpgp::cert::components::Amalgamation;
     ///
     /// # fn main() { f().unwrap(); }
     /// # fn f() -> Result<()> {
diff --git a/openpgp/src/cert/components.rs b/openpgp/src/cert/components.rs
index 7b602cfd..0b9b2da6 100644
--- a/openpgp/src/cert/components.rs
+++ b/openpgp/src/cert/components.rs
@@ -23,6 +23,7 @@ use super::{
     canonical_signature_order,
 };
 pub use super::amalgamation::{
+    Amalgamation,
     ComponentAmalgamation,
     ValidComponentAmalgamation,
 };
diff --git a/openpgp/src/cert/key_amalgamation.rs b/openpgp/src/cert/key_amalgamation.rs
index 799873aa..31183b24 100644
--- a/openpgp/src/cert/key_amalgamation.rs
+++ b/openpgp/src/cert/key_amalgamation.rs
@@ -7,7 +7,10 @@ use std::ops::Deref;
 
 use crate::{
     Cert,
-    cert::components::KeyBinding,
+    cert::components::{
+        Amalgamation,
+        KeyBinding,
+    },
     Error,
     packet::key,
     packet::key::SecretKeyMaterial,
diff --git a/openpgp/src/cert/mod.rs b/openpgp/src/cert/mod.rs
index 06d97a0e..3b77be37 100644
--- a/openpgp/src/cert/mod.rs
+++ b/openpgp/src/cert/mod.rs
@@ -1286,6 +1286,7 @@ impl Cert {
 #[cfg(test)]
 mod test {
     use crate::serialize::Serialize;
+    use super::components::Amalgamation;
     use super::*;
 
     use crate::{
diff --git a/openpgp/src/cert/revoke.rs b/openpgp/src/cert/revoke.rs
index cc0748d7..986af9e4 100644
--- a/openpgp/src/cert/revoke.rs
+++ b/openpgp/src/cert/revoke.rs
@@ -268,6 +268,8 @@ impl Deref for SubkeyRevocationBuilder {
 ///
 /// ```
 /// # use sequoia_openpgp::{*, packet::*, types::*, cert::*};
+/// use sequoia_openpgp::cert::components::Amalgamation;
+///
 /// # f().unwrap();
 /// # fn f() -> Result<()> {
 /// // Generate a Cert, and create a keypair from the primary key.
@@ -380,6 +382,8 @@ impl Deref for UserIDRevocationBuilder {
 ///
 /// ```
 /// # use sequoia_openpgp::{*, packet::*, types::*, cert::*};
+/// use sequoia_openpgp::cert::components::Amalgamation;
+///
 /// # f().unwrap();
 /// # fn f() -> Result<()> {
 /// # let subpacket