Merge remote-tracking branch 'ssadler/fix/13' into fix/13

Adds a small test that uses an explicit tag.

src/lib.rs

@@ -401,7 +401,7 @@ pub enum ASN1EncodeErr {
 
 impl fmt::Display for ASN1EncodeErr {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.write_str(self.description())
+        f.write_str(&self.to_string())
     }
 }
 
@@ -1642,4 +1642,63 @@ mod tests {
             assert_eq!(raw_oid, &expected[6..(expected.len() - 4)]);
         }
     }
+
+    #[test]
+    fn openssl_ec_key_test() {
+        use ASN1Block::{Sequence, Explicit, Integer, ObjectIdentifier,
+          OctetString};
+
+        // Create openssl ec key
+        let private_key = vec![0, 1, 2, 3, 4, 5, 6, 7];
+        let der = to_der(
+            &ASN1Block::Sequence(0, vec![
+                // Version
+                ASN1Block::Integer(0, 1.into()),
+                // Private key
+                ASN1Block::OctetString(0, private_key.clone()),
+                // Parameters
+                // Explicitely tagged oid
+                // Oid: 1, 2, 840, 10045, 3, 1, 7,
+                ASN1Block::Explicit(ASN1Class::ContextSpecific, 0, 0u8.into(),
+                    Box::new(ASN1Block::ObjectIdentifier(0,
+                        OID::new(vec![
+                            1u8.into(), 2u8.into(), 840u16.into(),
+                            10045u16.into(), 3u8.into(), 1u8.into(), 7u8.into(),
+                        ])
+                )))
+            ])
+        ).unwrap();
+        let der_data = vec![48, 25, 2, 1, 1, 4, 8, 0, 1, 2, 3, 4, 5, 6, 7, 160,
+            10, 6, 8, 42, 134, 72, 206, 61, 3, 1, 7];
+
+        assert_eq!(der, der_data);
+
+        assert_eq!(
+            from_der(&der_data),
+            Ok(vec![Sequence(0, vec![Integer(2, 1u8.into()),
+                OctetString(5, private_key),
+                Explicit(ASN1Class::ContextSpecific, 15, 0u8.into(),
+                    Box::new(ObjectIdentifier(17, OID(vec![1u8.into(),
+                        2u8.into(), 840u16.into(), 10045u16.into(), 3u8.into(),
+                        1u8.into(), 7u8.into(),
+                    ]))))])]),
+        );
+    }
+
+    #[test]
+    fn encode_unknowns() {
+        fn encode_structure(bufs: &[Vec<u8>]) -> Vec<u8> {
+            let mut body = Vec::new();
+            for (i, buf) in bufs.iter().enumerate() {
+                let mut der = to_der(&ASN1Block::Unknown(ASN1Class::ContextSpecific, false, 0, BigUint::from_usize(i).unwrap(), buf.to_vec())).unwrap();
+                body.append(&mut der);
+            }
+            let block = ASN1Block::Unknown(ASN1Class::ContextSpecific, true, 0, BigUint::from_u8(0).unwrap(), body);
+            to_der(&block).unwrap()
+        }
+
+        let decoded = from_der(&encode_structure(&vec![vec![0]])).unwrap();
+        let expected = [ASN1Block::Unknown(ASN1Class::ContextSpecific, true, 0, BigUint::from_u8(0).unwrap(), vec![128, 1, 0])];
+        assert_eq!(decoded, expected);
+    }
 }