Initial implementation (#1)

src/errors.rs

@@ -0,0 +1,57 @@
+// Copyright (c) Facebook, Inc. and its affiliates.
+//
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+
+//! A list of error types which are produced during an execution of the protocol
+use core::fmt::Debug;
+#[cfg(feature = "std")]
+use std::error::Error;
+
+use displaydoc::Display;
+
+/// Represents an error in the manipulation of internal cryptographic data
+#[derive(Clone, Display, Eq, Hash, PartialEq)]
+pub enum InternalError {
+    /// Could not parse byte sequence for key
+    InvalidByteSequence,
+    /// Invalid length for {name}: expected {len}, but is actually {actual_len}.
+    SizeError {
+        /// name
+        name: &'static str,
+        /// length
+        len: usize,
+        /// actual
+        actual_len: usize,
+    },
+    /// Could not decompress point.
+    PointError,
+    /// Computing the hash-to-curve function failed
+    HashToCurveError,
+    /// Failure to serialize or deserialize bytes
+    SerializationError,
+}
+
+impl Debug for InternalError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            Self::InvalidByteSequence => f.debug_tuple("InvalidByteSequence").finish(),
+            Self::SizeError {
+                name,
+                len,
+                actual_len,
+            } => f
+                .debug_struct("SizeError")
+                .field("name", name)
+                .field("len", len)
+                .field("actual_len", actual_len)
+                .finish(),
+            Self::PointError => f.debug_tuple("PointError").finish(),
+            Self::HashToCurveError => f.debug_tuple("HashToCurveError").finish(),
+            Self::SerializationError => f.debug_tuple("SerializationError").finish(),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl Error for InternalError {}