1 files changed, 59 insertions, 0 deletions
diff --git a/diced/open_dice/src/error.rs b/diced/open_dice/src/error.rs
new file mode 100644
index 00000000..4c673354
--- /dev/null
+++ b/diced/open_dice/src/error.rs
@@ -0,0 +1,59 @@
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Errors and relating functions thrown in this library.
+
+use open_dice_cbor_bindgen::DiceResult;
+use std::{fmt, result};
+
+#[cfg(feature = "std")]
+use std::error::Error;
+
+/// Error type used by DICE.
+#[derive(Debug)]
+pub enum DiceError {
+    /// Provided input was invalid.
+    InvalidInput,
+    /// Provided buffer was too small.
+    BufferTooSmall,
+    /// Platform error.
+    PlatformError,
+}
+
+/// This makes `DiceError` accepted by anyhow.
+#[cfg(feature = "std")]
+impl Error for DiceError {}
+
+impl fmt::Display for DiceError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::InvalidInput => write!(f, "invalid input"),
+            Self::BufferTooSmall => write!(f, "buffer too small"),
+            Self::PlatformError => write!(f, "platform error"),
+        }
+    }
+}
+
+/// DICE result type.
+pub type Result<T> = result::Result<T, DiceError>;
+
+/// Checks the given `DiceResult`. Returns an error if it's not OK.
+pub fn check_result(result: DiceResult) -> Result<()> {
+    match result {
+        DiceResult::kDiceResultOk => Ok(()),
+        DiceResult::kDiceResultInvalidInput => Err(DiceError::InvalidInput),
+        DiceResult::kDiceResultBufferTooSmall => Err(DiceError::BufferTooSmall),
+        DiceResult::kDiceResultPlatformError => Err(DiceError::PlatformError),
+    }
+}