1 /*
2  * Copyright (C) 2024 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 //! Helper functions that includes data transformation for AIDL types.
18 
19 /// Macro to create enums that can easily be used as cose labels for serialization
20 /// It expects the macro definition to have the following form:
21 ///
22 /// cose_enum_gen! {
23 ///     enum CoseEnumName {
24 ///         CoseEnumField1 = value1,
25 ///         CoseEnumField2 = value2,
26 ///     }
27 /// }
28 #[macro_export]
29 macro_rules! cose_enum_gen {
30     (enum $name:ident {$($field:ident = $field_val:literal),+ $(,)*}) => {
31         enum $name {
32             $($field = $field_val),+
33         }
34 
35         impl TryFrom<i64> for $name {
36             type Error = hwcryptohal_common::err::HwCryptoError;
37 
38             fn try_from(value: i64) -> Result<Self, Self::Error> {
39                 match value {
40                     $(x if x == $name::$field as i64 => Ok($name::$field)),+,
41                     _ => Err(hwcrypto_err!(SERIALIZATION_ERROR, "unsupported COSE enum label val {}", value)),
42                 }
43             }
44         }
45 
46         impl TryFrom<ciborium::value::Integer> for $name {
47             type Error = coset::CoseError;
48 
49             fn try_from(value: ciborium::value::Integer) -> Result<Self, Self::Error> {
50                 let value: i64 = value.try_into()?;
51                 Ok(value.try_into().map_err(|_| coset::CoseError::EncodeFailed)?)
52             }
53         }
54     }
55 }
56