Generalise ENR key type (#12)

* Allow arbitrary bytes as keys

* Clippy lints

Author: AgeManning

src/builder.rs

@@ -1,3 +1,4 @@
+use crate::Key;
 use crate::{Enr, EnrError, EnrKey, EnrPublicKey, NodeId, MAX_ENR_SIZE};
 use rlp::RlpStream;
 use std::{collections::BTreeMap, marker::PhantomData, net::IpAddr};
@@ -11,7 +12,7 @@ pub struct EnrBuilder<K: EnrKey> {
     seq: u64,
 
     /// The key-value pairs for the ENR record.
-    content: BTreeMap<String, Vec<u8>>,
+    content: BTreeMap<Key, Vec<u8>>,
 
     /// Pins the generic key types.
     phantom: PhantomData<K>,
@@ -37,21 +38,19 @@ impl<K: EnrKey> EnrBuilder<K> {
     }
 
     /// Adds an arbitrary key-value to the `ENRBuilder`.
-    pub fn add_value(&mut self, key: String, value: Vec<u8>) -> &mut Self {
-        self.content.insert(key, value);
+    pub fn add_value(&mut self, key: impl AsRef<[u8]>, value: Vec<u8>) -> &mut Self {
+        self.content.insert(key.as_ref().to_vec(), value);
         self
     }
 
     /// Adds an `ip` field to the `ENRBuilder`.
     pub fn ip(&mut self, ip: IpAddr) -> &mut Self {
         match ip {
             IpAddr::V4(addr) => {
-                self.content
-                    .insert(String::from("ip"), addr.octets().to_vec());
+                self.content.insert(b"ip".to_vec(), addr.octets().to_vec());
             }
             IpAddr::V6(addr) => {
-                self.content
-                    .insert(String::from("ip6"), addr.octets().to_vec());
+                self.content.insert(b"ip6".to_vec(), addr.octets().to_vec());
             }
         }
         self

src/keys/combined.rs

@@ -10,6 +10,8 @@ pub use secp256k1;
 use std::collections::BTreeMap;
 use zeroize::Zeroize;
 
+use crate::Key;
+
 /// A standard implementation of the `EnrKey` trait used to sign and modify ENR records. The variants here represent the currently
 /// supported in-built signing schemes.
 pub enum CombinedKey {
@@ -64,7 +66,7 @@ impl EnrKey for CombinedKey {
     }
 
     /// Decodes the raw bytes of an ENR's content into a public key if possible.
-    fn enr_to_public(content: &BTreeMap<String, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
+    fn enr_to_public(content: &BTreeMap<Key, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
         secp256k1::SecretKey::enr_to_public(content)
             .map(CombinedPublicKey::Secp256k1)
             .or_else(|_| ed25519::Keypair::enr_to_public(content).map(CombinedPublicKey::from))
@@ -178,7 +180,7 @@ impl EnrPublicKey for CombinedPublicKey {
     }
 
     /// Generates the ENR public key string associated with the key type.
-    fn enr_key(&self) -> String {
+    fn enr_key(&self) -> Key {
         match self {
             Self::Secp256k1(key) => key.enr_key(),
             Self::Ed25519(key) => key.enr_key(),

src/keys/ed25519.rs

@@ -2,6 +2,7 @@ use super::{
     ed25519_dalek::{self as ed25519, Signer as _, Verifier as _},
     EnrKey, EnrPublicKey, SigningError,
 };
+use crate::Key;
 use rlp::DecoderError;
 use std::{collections::BTreeMap, convert::TryFrom};
 
@@ -25,9 +26,9 @@ impl EnrKey for ed25519::Keypair {
     }
 
     /// Decodes the raw bytes of an ENR's content into a public key if possible.
-    fn enr_to_public(content: &BTreeMap<String, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
+    fn enr_to_public(content: &BTreeMap<Key, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
         let pubkey_bytes = content
-            .get(ENR_KEY)
+            .get(ENR_KEY.as_bytes())
             .ok_or_else(|| DecoderError::Custom("Unknown signature"))?;
         ed25519::PublicKey::from_bytes(pubkey_bytes)
             .map_err(|_| DecoderError::Custom("Invalid ed25519 Signature"))
@@ -54,7 +55,7 @@ impl EnrPublicKey for ed25519::PublicKey {
     }
 
     /// Generates the ENR public key string associated with the ed25519 key type.
-    fn enr_key(&self) -> String {
+    fn enr_key(&self) -> Key {
         ENR_KEY.into()
     }
 }

src/keys/k256.rs

@@ -1,6 +1,7 @@
 //! An implementation for `EnrKey` for `k256::SecretKey`
 
 use super::{EnrKey, EnrPublicKey, SigningError};
+use crate::Key;
 use k256_crate::{
     ecdsa::signature::{DigestVerifier, RandomizedDigestSigner, Signature},
     elliptic_curve::weierstrass::public_key::FromPublicKey,
@@ -36,9 +37,9 @@ impl EnrKey for k256_crate::SecretKey {
         self.try_into().unwrap()
     }
 
-    fn enr_to_public(content: &BTreeMap<String, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
+    fn enr_to_public(content: &BTreeMap<Key, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
         let pubkey_bytes = content
-            .get(ENR_KEY)
+            .get(ENR_KEY.as_bytes())
             .ok_or_else(|| DecoderError::Custom("Unknown signature"))?;
 
         // should be encoded in compressed form, i.e 33 byte raw secp256k1 public key
@@ -75,7 +76,7 @@ impl EnrPublicKey for k256_crate::PublicKey {
             .to_vec()
     }
 
-    fn enr_key(&self) -> String {
+    fn enr_key(&self) -> Key {
         ENR_KEY.into()
     }
 }

src/keys/libsecp256k1.rs

@@ -2,6 +2,7 @@
 
 use super::{secp256k1, EnrKey, EnrPublicKey, SigningError};
 use crate::digest;
+use crate::Key;
 use rlp::DecoderError;
 use std::collections::BTreeMap;
 
@@ -30,9 +31,9 @@ impl EnrKey for secp256k1::SecretKey {
     }
 
     /// Decodes the raw bytes of an ENR's content into a public key if possible.
-    fn enr_to_public(content: &BTreeMap<String, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
+    fn enr_to_public(content: &BTreeMap<Key, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
         let pubkey_bytes = content
-            .get(ENR_KEY)
+            .get(ENR_KEY.as_bytes())
             .ok_or_else(|| DecoderError::Custom("Unknown signature"))?;
         // should be encoded in compressed form, i.e 33 byte raw secp256k1 public key
         secp256k1::PublicKey::parse_slice(
@@ -69,7 +70,7 @@ impl EnrPublicKey for secp256k1::PublicKey {
     }
 
     /// Generates the ENR public key string associated with the secp256k1 key type.
-    fn enr_key(&self) -> String {
+    fn enr_key(&self) -> Key {
         ENR_KEY.into()
     }
 }

src/keys/mod.rs

@@ -28,6 +28,7 @@ pub use ed25519_dalek;
 #[cfg(any(feature = "libsecp256k1", doc))]
 pub use secp256k1;
 
+use crate::Key;
 use rlp::DecoderError;
 use std::{
     collections::BTreeMap,
@@ -51,7 +52,7 @@ pub trait EnrKey {
     /// `EnrPublicKey`. It takes the ENR's `BTreeMap` and returns a public key.
     ///
     /// Note: This specifies the supported key schemes for an ENR.
-    fn enr_to_public(content: &BTreeMap<String, Vec<u8>>) -> Result<Self::PublicKey, DecoderError>;
+    fn enr_to_public(content: &BTreeMap<Key, Vec<u8>>) -> Result<Self::PublicKey, DecoderError>;
 }
 
 /// The trait required for a `PublicKey` to verify an ENR record.
@@ -68,7 +69,7 @@ pub trait EnrPublicKey {
 
     /// Returns the ENR key identifier for the public key type. For `secp256k1` keys this
     /// is `secp256k1`.
-    fn enr_key(&self) -> String;
+    fn enr_key(&self) -> Key;
 }
 
 /// An error during signing of a message.

src/keys/rust_secp256k1.rs

@@ -1,5 +1,6 @@
 use super::{EnrKey, EnrPublicKey, SigningError};
 use crate::digest;
+use crate::Key;
 use rlp::DecoderError;
 use std::collections::BTreeMap;
 
@@ -25,9 +26,9 @@ impl EnrKey for c_secp256k1::SecretKey {
         Self::PublicKey::from_secret_key(&c_secp256k1::Secp256k1::new(), self)
     }
 
-    fn enr_to_public(content: &BTreeMap<String, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
+    fn enr_to_public(content: &BTreeMap<Key, Vec<u8>>) -> Result<Self::PublicKey, DecoderError> {
         let pubkey_bytes = content
-            .get(ENR_KEY)
+            .get(ENR_KEY.as_bytes())
             .ok_or_else(|| DecoderError::Custom("Unknown signature"))?;
         // should be encoded in compressed form, i.e 33 byte raw secp256k1 public key
         c_secp256k1::PublicKey::from_slice(pubkey_bytes)
@@ -54,7 +55,7 @@ impl EnrPublicKey for c_secp256k1::PublicKey {
         self.serialize_uncompressed()[1..].to_vec()
     }
 
-    fn enr_key(&self) -> String {
+    fn enr_key(&self) -> Key {
         ENR_KEY.into()
     }
 }