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

//! CJDNS API. Used for easy, fast and safe creation of random key pair.

use std::convert::TryFrom;

use cjdns_crypto::random::DefaultRandom;

use crate::{CJDNS_IP6, CJDNSPrivateKey, CJDNSPublicKey};

/// Type that encapsulates some crate functions making it safer for its users to work with randomly created keys.
///
/// The struct initialization ensures thread-safety in runtime. If you don't need to work with randomly created keys, you can use appropriate key types directly.
pub struct CJDNSKeysApi {
    random: DefaultRandom
}

/// Convenience type for managing all CJDNS key types in one variable.
///
/// Fields of the struct are public, so it's possible to create invalid key pair. For example: there is a contract between ip6 and public key, which requires successful initialization of ip6 from public key.
/// `CJDNSKeys` doesn't control the contract, so it's possible to have valid keys on their own, but invalid in "pair". So if you wrap your keys with `CJDNSKeys`,
/// make sure that the contract requirements are met. For safe random keys initialization use `CJDNSKeysApi` struct methods.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct CJDNSKeys {
    /// CJDNS private key.
    pub private_key: CJDNSPrivateKey,

    /// CJDNS public key
    pub public_key: CJDNSPublicKey,

    /// CJDNS ip6
    pub ip6: CJDNS_IP6,
}

impl CJDNSKeysApi {
    /// Initialization function, which guarantees on success that it will be safe to call methods
    /// which use "randomize" logic (i.e. `key_pair`, `gen_private_key`).
    ///
    /// If you want to work with randomly created cjdns keys,
    /// it's recommended to first initialize `CJDNSKeysApi`.
    /// For example:
    /// ```rust
    /// use cjdns_keys::CJDNSKeysApi;
    ///
    /// let keys_api = CJDNSKeysApi::new().expect("thread-safe initialization failed");
    /// // valid random key pair
    /// let keys = keys_api.key_pair();
    /// ```
    pub fn new() -> std::result::Result<Self, ()> {
        Ok(
            CJDNSKeysApi {
                random: DefaultRandom::new()?
            }
        )
    }

    /// Convenience method that generates safely valid key "pair". Returns `CJDNSKeys` struct with corresponding keys as its fields.
    ///
    /// `CJDNSKeys` doc states presence of a contract between ip6 and public key. The contract is met within the method.
    pub fn key_pair(&self) -> CJDNSKeys {
        loop {
            let private_key = self.gen_private_key();
            let public_key = CJDNSPublicKey::from(&private_key);
            let ip6_candidate = CJDNS_IP6::try_from(&public_key);

            if let Ok(ip6) = ip6_candidate {
                return CJDNSKeys { private_key, public_key, ip6 };
            }
        }
    }

    /// Safely generates private key.
    ///
    /// Considered safe, because the method takes immutable reference of the successfully initialized api type instance.
    pub fn gen_private_key(&self) -> CJDNSPrivateKey {
        CJDNSPrivateKey::new_random(&self.random)
    }
}

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

    fn priv_key(s: &'static str) -> CJDNSPrivateKey {
        CJDNSPrivateKey::try_from(s).expect("bad test private key")
    }

    fn pub_key(s: &'static str) -> CJDNSPublicKey {
        CJDNSPublicKey::try_from(s).expect("bad test public key")
    }

    fn ipv6(s: &'static str) -> CJDNS_IP6 {
        CJDNS_IP6::try_from(s).expect("bad test ipv6")
    }

    #[test]
    fn test_base() {
        let key_pair = CJDNSKeys {
            private_key: priv_key("378813dfecc62185ffab4d00030b55f50b54e515bfcea8b41f2bd1c2511bae03"),
            public_key: pub_key("qgkjd0stfvk9r3j28s4gh8rgslbgx2r5xgxzxkgm5vdxqwn8xsu0.k"),
            ip6: ipv6("fcf5:c1ec:be67:9ad5:1f6c:f31b:5d74:37b0"),
        };

        let pub_key_bytes = &*key_pair.public_key;
        let mut pub_key_bytes_array = [0u8; 32];
        pub_key_bytes_array.copy_from_slice(&pub_key_bytes);
        assert_eq!(CJDNSPublicKey::from(pub_key_bytes_array), key_pair.public_key);

        assert_eq!(CJDNS_IP6::try_from(&*key_pair.ip6).expect("broken bytes()"), key_pair.ip6);
    }
}