Merge pull request #6 from interchainio/validator_set

Validator Set Hash

src/lib.rs

@@ -58,6 +58,7 @@ mod serializers;
 pub mod signature;
 pub mod time;
 mod timeout;
+#[cfg(feature = "amino-types")]
 pub mod validator;
 mod version;
 pub mod vote;

src/merkle.rs

@@ -5,8 +5,11 @@ use sha2::{Digest, Sha256};
 /// Size of Merkle root hash
 pub const HASH_SIZE: usize = 32;
 
+/// Hash is the output of the cryptographic digest function
+pub type Hash = [u8; HASH_SIZE];
+
 /// Compute a simple Merkle root from the arbitrary sized byte slices
-pub fn simple_hash_from_byte_slices(byte_slices: &[&[u8]]) -> [u8; HASH_SIZE] {
+pub fn simple_hash_from_byte_slices(byte_slices: &[&[u8]]) -> Hash {
     let length = byte_slices.len();
     match length {
         0 => [0; HASH_SIZE],
@@ -31,7 +34,7 @@ fn get_split_point(length: usize) -> usize {
 }
 
 // tmhash(0x00 || leaf)
-fn leaf_hash(bytes: &[u8]) -> [u8; HASH_SIZE] {
+fn leaf_hash(bytes: &[u8]) -> Hash {
     // make a new array starting with 0 and copy in the bytes
     let mut leaf_bytes = Vec::with_capacity(bytes.len() + 1);
     leaf_bytes.push(0x00);
@@ -47,7 +50,7 @@ fn leaf_hash(bytes: &[u8]) -> [u8; HASH_SIZE] {
 }
 
 // tmhash(0x01 || left || right)
-fn inner_hash(left: &[u8], right: &[u8]) -> [u8; HASH_SIZE] {
+fn inner_hash(left: &[u8], right: &[u8]) -> Hash {
     // make a new array starting with 0x1 and copy in the bytes
     let mut inner_bytes = Vec::with_capacity(left.len() + right.len() + 1);
     inner_bytes.push(0x01);

src/public_key.rs

@@ -62,6 +62,14 @@ impl PublicKey {
         }
     }
 
+    /// Serialize this key as raw bytes
+    pub fn as_bytes(self) -> Vec<u8> {
+        match self {
+            PublicKey::Ed25519(ref pk) => pk.as_bytes(),
+            PublicKey::Secp256k1(ref pk) => pk.as_bytes(),
+        }.to_vec()
+    }
+
     /// Serialize this key as amino bytes
     pub fn to_amino_bytes(self) -> Vec<u8> {
         match self {

src/validator.rs

@@ -1,14 +1,47 @@
 //! Tendermint validators
 
-use crate::{account, vote, PublicKey};
+use crate::{account, merkle, vote, PublicKey};
+use prost::Message;
 #[cfg(feature = "serde")]
 use serde::{de::Error as _, Deserialize, Deserializer, Serialize, Serializer};
 #[cfg(feature = "rpc")]
 use subtle_encoding::base64;
 
+/// Validator set contains a vector of validators
+#[derive(Debug)]
+pub struct Set {
+    validators: Vec<Info>,
+}
+
+impl Set {
+    /// Create a new validator set.
+    /// vals is mutable so it can be sorted by address.
+    pub fn new(mut vals: Vec<Info>) -> Set {
+        vals.sort_by(|v1, v2| v1.address.partial_cmp(&v2.address).unwrap());
+        Set { validators: vals }
+    }
+
+    /// Compute the Merkle root of the validator set
+    pub fn hash(self) -> merkle::Hash {
+        // We need to get from Vec<Info> to &[&[u8]] so we can call simple_hash_from_byte_slices.
+        // This looks like: Vec<Info> -> Vec<Vec<u8>> -> Vec<&[u8]> -> &[&[u8]]
+        // Can we simplify this?
+        // Perhaps simple_hash_from_byteslices should take Vec<Vec<u8>> directly ?
+        let validator_bytes: Vec<Vec<u8>> = self
+            .validators
+            .into_iter()
+            .map(|x| x.hash_bytes())
+            .collect();
+        let validator_byteslices: Vec<&[u8]> = (&validator_bytes)
+            .into_iter()
+            .map(|x| x.as_slice())
+            .collect();
+        merkle::simple_hash_from_byte_slices(validator_byteslices.as_slice())
+    }
+}
+
 /// Validator information
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug)]
 pub struct Info {
     /// Validator account address
     pub address: account::Id,
@@ -23,6 +56,61 @@ pub struct Info {
     pub proposer_priority: Option<ProposerPriority>,
 }
 
+impl From<PublicKey> for account::Id {
+    fn from(pub_key: PublicKey) -> account::Id {
+        match pub_key {
+            PublicKey::Ed25519(pk) => account::Id::from(pk),
+            PublicKey::Secp256k1(pk) => account::Id::from(pk),
+        }
+    }
+}
+
+impl Info {
+    /// Create a new validator.
+    pub fn new(pk: PublicKey, vp: vote::Power) -> Info {
+        Info {
+            address: account::Id::from(pk),
+            pub_key: pk,
+            voting_power: vp,
+            proposer_priority: None,
+        }
+    }
+}
+
+/// InfoHashable is the form of the validator used for computing the Merkle tree.
+/// It does not include the address, as that is redundant with the pubkey,
+/// nor the proposer priority, as that changes with every block even if the validator set didn't.
+/// It contains only the pubkey and the voting power, and is amino encoded.
+/// TODO: currently only works for Ed25519 pubkeys
+#[derive(Clone, PartialEq, Message)]
+struct InfoHashable {
+    #[prost(bytes, tag = "1", amino_name = "tendermint/PubKeyEd25519")]
+    pub pub_key: Vec<u8>,
+    #[prost(uint64, tag = "2")]
+    voting_power: u64,
+}
+
+/// Info -> InfoHashable
+impl From<&Info> for InfoHashable {
+    fn from(info: &Info) -> InfoHashable {
+        InfoHashable {
+            pub_key: info.pub_key.as_bytes(),
+            voting_power: info.voting_power.value(),
+        }
+    }
+}
+
+// returns the bytes to be hashed into the Merkle tree -
+// the leaves of the tree. this is an amino encoding of the 
+// pubkey and voting power, so it includes the pubkey's amino prefix.
+impl Info {
+    fn hash_bytes(&self) -> Vec<u8> {
+        let mut bytes: Vec<u8> = Vec::new();
+        InfoHashable::from(self).encode(&mut bytes).unwrap();
+        bytes
+    }
+}
+
 /// Proposer priority
 #[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
 pub struct ProposerPriority(i64);
@@ -60,7 +148,7 @@ impl Serialize for ProposerPriority {
 
 /// Updates to the validator set
 #[cfg(feature = "rpc")]
-#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Update {
     /// Validator public key
     #[serde(deserialize_with = "deserialize_public_key")]
@@ -99,3 +187,29 @@ where
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use subtle_encoding::hex;
+
+    // make a validator from a hex ed25519 pubkey and a voting power
+    fn make_validator(pk_string: &str, vp: u64) -> Info {
+        let pk = PublicKey::from_raw_ed25519(&hex::decode_upper(pk_string).unwrap()).unwrap();
+        Info::new(pk, vote::Power::new(vp))
+    }
+
+    #[test]
+    fn test_validator_set() {
+        // test vector generated by Go code
+        let v1 = make_validator("F349539C7E5EF7C49549B09C4BFC2335318AB0FE51FBFAA2433B4F13E816F4A7", 148151478422287875);
+        let v2 = make_validator("5646AA4C706B7AF73768903E77D117487D2584B76D83EB8FF287934EE7758AFC", 158095448483785107);
+        let v3 = make_validator("EB6B732C4BD86B5FA3F3BC3DB688DA0ED182A7411F81C2D405506B298FC19E52", 770561664770006272);
+        let hash_string = "B92B4474567A1B57969375C13CF8129AA70230642BD7FB9FB2CC316E87CE01D7";
+        let hash_expect = &hex::decode_upper(hash_string).unwrap();
+
+        let val_set = Set::new(vec![v1, v2, v3]);
+        let hash = val_set.hash();
+        assert_eq!(hash_expect, &hash);
+    }
+}

src/vote/power.rs

@@ -8,6 +8,11 @@ use serde::{de::Error as _, Deserialize, Deserializer, Serialize, Serializer};
 pub struct Power(u64);
 
 impl Power {
+    /// Create a new Power
+    pub fn new(p: u64) -> Power {
+        Power(p)
+    }
+
     /// Get the current voting power
     pub fn value(self) -> u64 {
         self.0