From 5a6e90428beeac34b773ea2ef157a01e5573394f Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Mon, 30 Mar 2020 09:29:29 +1100
Subject: [PATCH] Ensure attestations are created with empty signature (#960)

* Ensure attestations are created with empty sig

* Update docs
---
 beacon_node/beacon_chain/src/beacon_chain.rs             | 2 +-
 beacon_node/beacon_chain/tests/attestation_production.rs | 2 +-
 book/src/http_validator.md                               | 2 +-
 eth2/utils/bls/src/aggregate_signature.rs                | 7 +++++--
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/beacon_node/beacon_chain/src/beacon_chain.rs b/beacon_node/beacon_chain/src/beacon_chain.rs
index 1109dd2ab..9a2a3fad5 100644
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -756,7 +756,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                     root: target_root,
                 },
             },
-            signature: AggregateSignature::new(),
+            signature: AggregateSignature::empty_signature(),
         })
     }
 
diff --git a/beacon_node/beacon_chain/tests/attestation_production.rs b/beacon_node/beacon_chain/tests/attestation_production.rs
index 15fece863..3b84a78ff 100644
--- a/beacon_node/beacon_chain/tests/attestation_production.rs
+++ b/beacon_node/beacon_chain/tests/attestation_production.rs
@@ -106,7 +106,7 @@ fn produces_attestations() {
             );
             assert_eq!(
                 attestation.signature,
-                AggregateSignature::new(),
+                AggregateSignature::empty_signature(),
                 "bad signature"
             );
             assert_eq!(data.index, index, "bad index");
diff --git a/book/src/http_validator.md b/book/src/http_validator.md
index 633bbffa2..da0d4bbbd 100644
--- a/book/src/http_validator.md
+++ b/book/src/http_validator.md
@@ -263,7 +263,7 @@ Returns a `Attestation` object with a default signature. The `signature` field s
             "root": "0xaefd23b384994dc0c1a6b77836bdb2f24f209ebfe6c4819324d9685f4a43b4e1"
         }
     },
-    "signature": "0xc00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
+    "signature": "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
 }
 ```
 
diff --git a/eth2/utils/bls/src/aggregate_signature.rs b/eth2/utils/bls/src/aggregate_signature.rs
index b3dc46025..8ea582a4c 100644
--- a/eth2/utils/bls/src/aggregate_signature.rs
+++ b/eth2/utils/bls/src/aggregate_signature.rs
@@ -32,9 +32,12 @@ impl AggregateSignature {
 
     /// Add (aggregate) a signature to the `AggregateSignature`.
     pub fn add(&mut self, signature: &Signature) {
-        if !self.is_empty {
-            self.aggregate_signature.add(signature.as_raw())
+        if self.is_empty {
+            self.aggregate_signature = RawAggregateSignature::new();
+            self.is_empty = false;
         }
+
+        self.aggregate_signature.add(signature.as_raw())
     }
 
     /// Add (aggregate) another `AggregateSignature`.