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

/*
 * Copyright 2020 Fluence Labs Limited
 *
 * 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.
 */
use crate::ed25519;
use crate::error::DecodingError;
use crate::key_pair::KeyFormat;
#[cfg(not(target_arch = "wasm32"))]
use crate::rsa;
use crate::secp256k1;
use serde::{Deserialize, Serialize};
use std::convert::TryFrom;

#[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
pub enum Signature {
    Ed25519(ed25519::Signature),
    #[cfg(not(target_arch = "wasm32"))]
    Rsa(rsa::Signature),
    Secp256k1(secp256k1::Signature),
}

pub struct RawSignature {
    pub bytes: Vec<u8>,
    pub sig_type: KeyFormat,
}

impl Signature {
    fn get_prefix(&self) -> u8 {
        use Signature::*;
        match self {
            Ed25519(_) => KeyFormat::Ed25519.into(),
            #[cfg(not(target_arch = "wasm32"))]
            Rsa(_) => KeyFormat::Rsa.into(),
            Secp256k1(_) => KeyFormat::Secp256k1.into(),
        }
    }

    /// encode keypair type in first byte and signature as byte array
    pub fn encode(&self) -> Vec<u8> {
        use Signature::*;

        let mut result: Vec<u8> = vec![self.get_prefix()];

        match self {
            Ed25519(sig) => result.extend(sig.0.clone()),
            #[cfg(not(target_arch = "wasm32"))]
            Rsa(sig) => result.extend(sig.0.clone()),
            Secp256k1(sig) => result.extend(sig.0.clone()),
        }

        result
    }

    /// decode with first byte set as keypair type
    pub fn decode(bytes: Vec<u8>) -> Result<Self, DecodingError> {
        match KeyFormat::try_from(bytes[0])? {
            KeyFormat::Ed25519 => Ok(Signature::Ed25519(ed25519::Signature(bytes[1..].to_vec()))),
            #[cfg(not(target_arch = "wasm32"))]
            KeyFormat::Rsa => Ok(Signature::Rsa(rsa::Signature(bytes[1..].to_vec()))),
            KeyFormat::Secp256k1 => Ok(Signature::Secp256k1(secp256k1::Signature(
                bytes[1..].to_vec(),
            ))),
        }
    }

    pub fn to_vec(&self) -> &[u8] {
        use Signature::*;

        match self {
            Ed25519(sig) => &sig.0,
            #[cfg(not(target_arch = "wasm32"))]
            Rsa(sig) => &sig.0,
            Secp256k1(sig) => &sig.0,
        }
    }

    pub fn get_signature_type(&self) -> KeyFormat {
        use Signature::*;

        match self {
            Ed25519(_) => KeyFormat::Ed25519,
            #[cfg(not(target_arch = "wasm32"))]
            Rsa(_) => KeyFormat::Rsa,
            Secp256k1(_) => KeyFormat::Secp256k1,
        }
    }

    pub fn get_raw_signature(&self) -> RawSignature {
        RawSignature {
            bytes: self.to_vec().to_vec(),
            sig_type: self.get_signature_type(),
        }
    }

    pub fn from_bytes(key_format: KeyFormat, bytes: Vec<u8>) -> Self {
        match key_format {
            KeyFormat::Ed25519 => Signature::Ed25519(ed25519::Signature(bytes)),
            #[cfg(not(target_arch = "wasm32"))]
            KeyFormat::Rsa => Signature::Rsa(rsa::Signature(bytes)),
            KeyFormat::Secp256k1 => Signature::Secp256k1(secp256k1::Signature(bytes)),
        }
    }
}

#[cfg(test)]
mod tests {
    use crate::*;

    #[test]
    fn signature_encode_decode() {
        let bytes: Vec<u8> = (0..10).collect();
        let ed25519_sig = Signature::Ed25519(crate::ed25519::Signature(bytes.clone()));
        let secp256k1_sig = Signature::Secp256k1(crate::secp256k1::Signature(bytes.clone()));
        #[cfg(not(target_arch = "wasm32"))]
        let rsa_sig = Signature::Rsa(crate::rsa::Signature(bytes.clone()));

        assert_eq!(
            Signature::decode(ed25519_sig.encode()).unwrap(),
            ed25519_sig
        );
        assert_eq!(
            Signature::decode(secp256k1_sig.encode()).unwrap(),
            secp256k1_sig
        );
        #[cfg(not(target_arch = "wasm32"))]
        assert_eq!(Signature::decode(rsa_sig.encode()).unwrap(), rsa_sig);
    }
}