Combine error variants into general decryption

protocol/src/lib.rs

@@ -87,10 +87,8 @@ pub enum Error {
     SecretMaterialsGeneration(secp256k1::Error),
     /// Deriving the shared secrets was unsuccessful.
     SecretExpansion,
-    /// The authentication data was not correct when decoding a packet.
-    Cipher(fschacha20poly1305::Error),
-    /// The internal counters of the ciphers are not in sync.
-    OutOfSync,
+    /// General decryption error, channel could be out of sync.
+    Decryption(fschacha20poly1305::Error),
 }
 
 impl fmt::Display for Error {
@@ -114,8 +112,7 @@ impl fmt::Display for Error {
                 write!(f, "More than 4095 bytes of garbage in the handshake.")
             }
             Error::HandshakeOutOfOrder => write!(f, "Handshake flow out of sequence."),
-            Error::Cipher(e) => write!(f, "Cipher encryption/decrytion error: {}.", e),
-            Error::OutOfSync => write!(f, "Ciphers are out of sync."),
+            Error::Decryption(e) => write!(f, "Decrytion error: {}.", e),
             Error::SecretExpansion => write!(f, "Unable to expand key."),
         }
     }
@@ -129,8 +126,7 @@ impl std::error::Error for Error {
             Error::CiphertextTooSmall => None,
             Error::MaxGarbageLength => None,
             Error::HandshakeOutOfOrder => None,
-            Error::Cipher(e) => Some(e),
-            Error::OutOfSync => None,
+            Error::Decryption(e) => Some(e),
             Error::SecretExpansion => None,
             Error::BufferTooSmall { required_bytes: _ } => None,
         }
@@ -145,7 +141,7 @@ impl From<secp256k1::Error> for Error {
 
 impl From<fschacha20poly1305::Error> for Error {
     fn from(e: fschacha20poly1305::Error) -> Self {
-        Error::Cipher(e)
+        Error::Decryption(e)
     }
 }