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

//! Tendermint node IDs

use core::{
    fmt::{self, Debug, Display},
    str::FromStr,
};

use serde::{de, Deserialize, Deserializer, Serialize, Serializer};
use subtle::{self, ConstantTimeEq};
use subtle_encoding::hex;

use crate::{error::Error, prelude::*};

/// Length of a Node ID in bytes
pub const LENGTH: usize = 20;

/// Node IDs
#[allow(clippy::derived_hash_with_manual_eq)]
#[derive(Copy, Clone, Eq, Hash, PartialOrd, Ord)]
pub struct Id([u8; LENGTH]);

impl Id {
    /// Create a new Node ID from raw bytes
    pub fn new(bytes: [u8; LENGTH]) -> Id {
        Id(bytes)
    }

    /// Borrow the node ID as a byte slice
    pub fn as_bytes(&self) -> &[u8] {
        &self.0[..]
    }
}

impl AsRef<[u8]> for Id {
    fn as_ref(&self) -> &[u8] {
        self.as_bytes()
    }
}

impl ConstantTimeEq for Id {
    fn ct_eq(&self, other: &Id) -> subtle::Choice {
        self.as_bytes().ct_eq(other.as_bytes())
    }
}

impl Display for Id {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        for byte in &self.0 {
            write!(f, "{byte:02x}")?;
        }
        Ok(())
    }
}

impl Debug for Id {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "node::Id({self})")
    }
}

#[cfg(feature = "rust-crypto")]
mod key_conversions {
    use super::{Id, LENGTH};
    use crate::crypto::default::Sha256;
    use crate::public_key::{Ed25519, PublicKey};
    use crate::Error;
    use digest::Digest;

    impl From<Ed25519> for Id {
        fn from(pk: Ed25519) -> Id {
            let digest = Sha256::digest(pk.as_bytes());
            let mut bytes = [0u8; LENGTH];
            bytes.copy_from_slice(&digest[..LENGTH]);
            Id(bytes)
        }
    }

    impl TryFrom<PublicKey> for Id {
        type Error = Error;

        fn try_from(pk: PublicKey) -> Result<Self, Self::Error> {
            match pk {
                PublicKey::Ed25519(ed25519) => Ok(Id::from(ed25519)),
                #[cfg(feature = "secp256k1")]
                _ => Err(Error::unsupported_key_type()),
            }
        }
    }
}

/// Decode Node ID from hex
impl FromStr for Id {
    type Err = Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        // Accept either upper or lower case hex
        let bytes = hex::decode_upper(s)
            .or_else(|_| hex::decode(s))
            .map_err(Error::subtle_encoding)?;

        if bytes.len() != LENGTH {
            return Err(Error::parse("invalid length".to_string()));
        }

        let mut result_bytes = [0u8; LENGTH];
        result_bytes.copy_from_slice(&bytes);
        Ok(Id(result_bytes))
    }
}

impl PartialEq for Id {
    fn eq(&self, other: &Id) -> bool {
        self.ct_eq(other).into()
    }
}

impl<'de> Deserialize<'de> for Id {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        let s = String::deserialize(deserializer)?;
        Self::from_str(&s).map_err(|_| {
            de::Error::custom(format!(
                "expected {}-character hex string, got {:?}",
                LENGTH * 2,
                s
            ))
        })
    }
}

impl Serialize for Id {
    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
        self.to_string().serialize(serializer)
    }
}