1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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.

use anyhow::{bail, ensure, Context, Result};
use serde::{Deserialize, Serialize};
use std::convert::TryInto;

use teaclave_crypto::*;

pub const FILE_AUTH_TAG_LENGTH: usize = 16;

#[derive(Copy, Clone, Default, Debug, Serialize, Deserialize, PartialEq)]
pub struct FileAuthTag {
    tag: [u8; FILE_AUTH_TAG_LENGTH],
}

impl FileAuthTag {
    pub fn from_bytes(input: &[u8]) -> Result<Self> {
        ensure!(input.len() == FILE_AUTH_TAG_LENGTH, "Invalid length");
        let mut file_auth_tag = FileAuthTag::default();
        file_auth_tag.tag.clone_from_slice(input);
        Ok(file_auth_tag)
    }

    pub fn from_hex(input: impl AsRef<str>) -> Result<Self> {
        let hex = hex::decode(input.as_ref()).context("Illegal AuthTag provided")?;
        let tag = hex
            .as_slice()
            .try_into()
            .context("Illegal AuthTag provided")?;
        Ok(FileAuthTag { tag })
    }

    pub fn to_hex(&self) -> String {
        hex::encode(self.tag)
    }

    pub fn to_bytes(&self) -> Vec<u8> {
        self.tag.to_vec()
    }

    #[cfg(test_mode)]
    pub fn mock() -> Self {
        Self {
            tag: [0; FILE_AUTH_TAG_LENGTH],
        }
    }
}

impl std::convert::From<[u8; FILE_AUTH_TAG_LENGTH]> for FileAuthTag {
    fn from(tag: [u8; FILE_AUTH_TAG_LENGTH]) -> Self {
        Self { tag }
    }
}

impl std::cmp::PartialEq<[u8]> for FileAuthTag {
    fn eq(&self, other: &[u8]) -> bool {
        self.tag == other
    }
}

impl std::cmp::PartialEq<[u8; FILE_AUTH_TAG_LENGTH]> for FileAuthTag {
    fn eq(&self, other: &[u8; FILE_AUTH_TAG_LENGTH]) -> bool {
        &self.tag[..] == other
    }
}

#[derive(Copy, Clone, Debug, Serialize, Deserialize, PartialEq)]
pub enum FileCrypto {
    AesGcm128(AesGcm128Key),
    AesGcm256(AesGcm256Key),
    TeaclaveFile128(TeaclaveFile128Key),
    Raw,
}

impl FileCrypto {
    pub fn new(schema: &str, key: &[u8], iv: &[u8]) -> Result<Self> {
        let info = match schema {
            AesGcm128Key::SCHEMA => {
                let crypto = AesGcm128Key::new(key, iv)?;
                FileCrypto::AesGcm128(crypto)
            }
            AesGcm256Key::SCHEMA => {
                let crypto = AesGcm256Key::new(key, iv)?;
                FileCrypto::AesGcm256(crypto)
            }
            TeaclaveFile128Key::SCHEMA => {
                ensure!(iv.is_empty(), "IV is not empty for teaclave_file_128");
                let crypto = TeaclaveFile128Key::new(key)?;
                FileCrypto::TeaclaveFile128(crypto)
            }
            "raw" => FileCrypto::Raw,
            _ => bail!("Invalid crypto schema: {}", schema),
        };

        Ok(info)
    }

    pub fn schema(&self) -> &str {
        match self {
            FileCrypto::AesGcm128(_) => AesGcm128Key::SCHEMA,
            FileCrypto::AesGcm256(_) => AesGcm256Key::SCHEMA,
            FileCrypto::TeaclaveFile128(_) => TeaclaveFile128Key::SCHEMA,
            FileCrypto::Raw => "raw",
        }
    }

    pub fn key_iv(&self) -> (Vec<u8>, Vec<u8>) {
        match self {
            FileCrypto::AesGcm128(crypto) => (crypto.key.to_vec(), crypto.iv.to_vec()),
            FileCrypto::AesGcm256(crypto) => (crypto.key.to_vec(), crypto.iv.to_vec()),
            FileCrypto::TeaclaveFile128(crypto) => (crypto.key.to_vec(), Vec::new()),
            FileCrypto::Raw => (vec![], vec![]),
        }
    }
}

impl std::convert::From<AesGcm128Key> for FileCrypto {
    fn from(crypto: AesGcm128Key) -> Self {
        FileCrypto::AesGcm128(crypto)
    }
}

impl std::convert::From<AesGcm256Key> for FileCrypto {
    fn from(crypto: AesGcm256Key) -> Self {
        FileCrypto::AesGcm256(crypto)
    }
}

impl std::convert::From<TeaclaveFile128Key> for FileCrypto {
    fn from(crypto: TeaclaveFile128Key) -> Self {
        FileCrypto::TeaclaveFile128(crypto)
    }
}

impl Default for FileCrypto {
    fn default() -> Self {
        FileCrypto::TeaclaveFile128(TeaclaveFile128Key::random())
    }
}