openpgp: Explain binding signature lookup failures.

  - If looking up a binding signature fails, don't merely return None,
    but an Err(_) that explains the lookup failure.  For example, a
    binding signature may be present, but it may not meet the policy.

  - Fixes #460.

1 files changed, 7 insertions, 10 deletions

diff --git a/openpgp/src/policy.rs b/openpgp/src/policy.rs
index 9d1e49eb..3e31a595 100644
--- a/openpgp/src/policy.rs
+++ b/openpgp/src/policy.rs
@@ -1401,7 +1401,7 @@ mod test {
         let mut reject : StandardPolicy = StandardPolicy::new();
         reject.reject_hash(algo);
         assert!(cert.primary_key()
-                    .binding_signature(&reject, None).is_none());
+                    .binding_signature(&reject, None).is_err());
         assert_match!(RevocationStatus::NotAsFarAsWeKnow
                       = cert_revoked.revoked(&reject, None));
 
@@ -1411,8 +1411,7 @@ mod test {
             algo,
             SystemTime::now() + Duration::from_secs(SECS_IN_YEAR),
             SystemTime::now() + Duration::from_secs(SECS_IN_YEAR));
-        assert!(cert.primary_key()
-                    .binding_signature(&reject, None).is_some());
+        cert.primary_key().binding_signature(&reject, None)?;
         assert_match!(RevocationStatus::Revoked(_)
                       = cert_revoked.revoked(&reject, None));
 
@@ -1423,7 +1422,7 @@ mod test {
             SystemTime::now() - Duration::from_secs(SECS_IN_YEAR),
             SystemTime::now() - Duration::from_secs(SECS_IN_YEAR));
         assert!(cert.primary_key()
-                    .binding_signature(&reject, None).is_none());
+                    .binding_signature(&reject, None).is_err());
         assert_match!(RevocationStatus::NotAsFarAsWeKnow
                       = cert_revoked.revoked(&reject, None));
 
@@ -1435,7 +1434,7 @@ mod test {
             SystemTime::now() - Duration::from_secs(SECS_IN_YEAR),
             SystemTime::now() + Duration::from_secs(SECS_IN_YEAR));
         assert!(cert.primary_key()
-                    .binding_signature(&reject, None).is_none());
+                    .binding_signature(&reject, None).is_err());
         assert_match!(RevocationStatus::Revoked(_)
                       = cert_revoked.revoked(&reject, None));
 
@@ -1451,8 +1450,7 @@ mod test {
             (algo_u8 + 1).into(),
             SystemTime::now() - Duration::from_secs(SECS_IN_YEAR),
             SystemTime::now() - Duration::from_secs(SECS_IN_YEAR));
-        assert!(cert.primary_key()
-                    .binding_signature(&reject, None).is_some());
+        cert.primary_key().binding_signature(&reject, None)?;
         assert_match!(RevocationStatus::Revoked(_)
                       = cert_revoked.revoked(&reject, None));
 
@@ -1465,7 +1463,7 @@ mod test {
             SystemTime::UNIX_EPOCH - Duration::from_secs(SECS_IN_YEAR),
             SystemTime::UNIX_EPOCH - Duration::from_secs(SECS_IN_YEAR));
         assert!(cert.primary_key()
-                    .binding_signature(&reject, None).is_none());
+                    .binding_signature(&reject, None).is_err());
         assert_match!(RevocationStatus::NotAsFarAsWeKnow
                       = cert_revoked.revoked(&reject, None));
 
@@ -1477,8 +1475,7 @@ mod test {
             algo,
             SystemTime::UNIX_EPOCH + Duration::from_secs(500 * SECS_IN_YEAR),
             SystemTime::UNIX_EPOCH + Duration::from_secs(500 * SECS_IN_YEAR));
-        assert!(cert.primary_key()
-                    .binding_signature(&reject, None).is_some());
+        cert.primary_key().binding_signature(&reject, None)?;
         assert_match!(RevocationStatus::Revoked(_)
                       = cert_revoked.revoked(&reject, None));