From b2fb2afb2813c4288a462c4a84bf6bf9ea7f7528 Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Wed, 13 Mar 2019 16:51:37 +1100
Subject: [PATCH] Revert "Move `PublicKey` to store uncomp. bytes."

This reverts commit bfa2e71b468e34eedcf847076aa29f3a53038bfd.
---
 eth2/utils/bls/src/aggregate_public_key.rs |  2 +-
 eth2/utils/bls/src/public_key.rs           | 56 ++++++----------------
 eth2/utils/bls/src/signature.rs            |  4 +-
 3 files changed, 18 insertions(+), 44 deletions(-)

diff --git a/eth2/utils/bls/src/aggregate_public_key.rs b/eth2/utils/bls/src/aggregate_public_key.rs
index 47c95d6c9..2174a43cb 100644
--- a/eth2/utils/bls/src/aggregate_public_key.rs
+++ b/eth2/utils/bls/src/aggregate_public_key.rs
@@ -14,7 +14,7 @@ impl AggregatePublicKey {
     }
 
     pub fn add(&mut self, public_key: &PublicKey) {
-        self.0.add(&public_key.as_raw())
+        self.0.add(public_key.as_raw())
     }
 
     /// Returns the underlying signature.
diff --git a/eth2/utils/bls/src/public_key.rs b/eth2/utils/bls/src/public_key.rs
index 3e2bff19e..c85760bbf 100644
--- a/eth2/utils/bls/src/public_key.rs
+++ b/eth2/utils/bls/src/public_key.rs
@@ -10,58 +10,39 @@ use ssz::{
 use std::default;
 use std::hash::{Hash, Hasher};
 
-/// A single BLS public key.
-///
-/// This struct stores an uncompressed public key as a byte vec. The reason we store bytes instead
-/// of the `RawPublicKey` struct is because it allows for building a hashmap of `PublicKey` much
-/// faster.
-///
-/// Storing as uncompressed bytes costs ~0.02% more time when adding a `PublicKey` to an
-/// `AggregateKey`, however it saves ~0.5ms each time you need to add a pubkey to a hashmap.
+/// A single BLS signature.
 ///
 /// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
 /// serialization).
 #[derive(Debug, Clone, Eq)]
-pub struct PublicKey {
-    bytes: Vec<u8>,
-}
+pub struct PublicKey(RawPublicKey);
 
 impl PublicKey {
     pub fn from_secret_key(secret_key: &SecretKey) -> Self {
-        let mut raw_key = RawPublicKey::from_secret_key(secret_key.as_raw());
-        let uncompressed_bytes = raw_key.as_uncompressed_bytes();
-        Self {
-            bytes: uncompressed_bytes,
-        }
+        PublicKey(RawPublicKey::from_secret_key(secret_key.as_raw()))
     }
 
     /// Returns the underlying signature.
-    pub fn as_raw(&self) -> RawPublicKey {
-        RawPublicKey::from_uncompressed_bytes(&self.bytes).expect("PublicKey in invalid state")
+    pub fn as_raw(&self) -> &RawPublicKey {
+        &self.0
     }
 
     /// Converts compressed bytes to PublicKey
     pub fn from_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
-        let mut pubkey = RawPublicKey::from_bytes(&bytes).map_err(|_| DecodeError::Invalid)?;
-        Ok(Self {
-            bytes: pubkey.as_uncompressed_bytes(),
-        })
+        let pubkey = RawPublicKey::from_bytes(&bytes).map_err(|_| DecodeError::Invalid)?;
+        Ok(PublicKey(pubkey))
     }
 
     /// Returns the PublicKey as (x, y) bytes
     pub fn as_uncompressed_bytes(&self) -> Vec<u8> {
-        self.bytes.clone()
+        RawPublicKey::as_uncompressed_bytes(&mut self.0.clone())
     }
 
     /// Converts (x, y) bytes to PublicKey
     pub fn from_uncompressed_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
-        // Do a conversion to check the bytes are valid.
-        let _pubkey =
+        let pubkey =
             RawPublicKey::from_uncompressed_bytes(&bytes).map_err(|_| DecodeError::Invalid)?;
-
-        Ok(Self {
-            bytes: bytes.to_vec(),
-        })
+        Ok(PublicKey(pubkey))
     }
 
     /// Returns the last 6 bytes of the SSZ encoding of the public key, as a hex string.
@@ -83,22 +64,15 @@ impl default::Default for PublicKey {
 
 impl Encodable for PublicKey {
     fn ssz_append(&self, s: &mut SszStream) {
-        s.append_vec(&self.as_raw().as_bytes());
+        s.append_vec(&self.0.as_bytes());
     }
 }
 
 impl Decodable for PublicKey {
     fn ssz_decode(bytes: &[u8], i: usize) -> Result<(Self, usize), DecodeError> {
         let (sig_bytes, i) = decode_ssz_list(bytes, i)?;
-        let mut raw_sig =
-            RawPublicKey::from_bytes(&sig_bytes).map_err(|_| DecodeError::TooShort)?;
-
-        Ok((
-            Self {
-                bytes: raw_sig.as_uncompressed_bytes(),
-            },
-            i,
-        ))
+        let raw_sig = RawPublicKey::from_bytes(&sig_bytes).map_err(|_| DecodeError::TooShort)?;
+        Ok((PublicKey(raw_sig), i))
     }
 }
 
@@ -125,7 +99,7 @@ impl<'de> Deserialize<'de> for PublicKey {
 
 impl TreeHash for PublicKey {
     fn hash_tree_root(&self) -> Vec<u8> {
-        hash(&self.as_raw().as_bytes())
+        hash(&self.0.as_bytes())
     }
 }
 
@@ -143,7 +117,7 @@ impl Hash for PublicKey {
     ///
     /// Use `ssz::Encode` to obtain the bytes required for consensus hashing.
     fn hash<H: Hasher>(&self, state: &mut H) {
-        self.bytes.hash(state)
+        self.as_uncompressed_bytes().hash(state)
     }
 }
 
diff --git a/eth2/utils/bls/src/signature.rs b/eth2/utils/bls/src/signature.rs
index 47e1dad2e..47598bc66 100644
--- a/eth2/utils/bls/src/signature.rs
+++ b/eth2/utils/bls/src/signature.rs
@@ -33,7 +33,7 @@ impl Signature {
 
     /// Verify the Signature against a PublicKey.
     pub fn verify(&self, msg: &[u8], domain: u64, pk: &PublicKey) -> bool {
-        self.0.verify(msg, domain, &pk.as_raw())
+        self.0.verify(msg, domain, pk.as_raw())
     }
 
     /// Verify the Signature against a PublicKey, where the message has already been hashed.
@@ -44,7 +44,7 @@ impl Signature {
         pk: &PublicKey,
     ) -> bool {
         self.0
-            .verify_hashed(x_real_hashed, x_imaginary_hashed, &pk.as_raw())
+            .verify_hashed(x_real_hashed, x_imaginary_hashed, pk.as_raw())
     }
 
     /// Returns the underlying signature.