From 324ff204802d7d38e13d4c6d4c77869654980bfb Mon Sep 17 00:00:00 2001
From: silverpill <silverpill@firemail.cc>
Date: Thu, 21 Oct 2021 11:55:27 +0000
Subject: [PATCH] Call manager contract to verify that user is allowed to sign
 up

---
 README.md                       |  1 +
 src/ethereum/gate.rs            | 31 +++++++++++++++++++++++++++++++
 src/ethereum/mod.rs             |  1 +
 src/ethereum/nft.rs             |  2 +-
 src/mastodon_api/users/views.rs |  8 ++++++++
 5 files changed, 42 insertions(+), 1 deletion(-)
 create mode 100644 src/ethereum/gate.rs

diff --git a/README.md b/README.md
index bce7aa3..6f9617d 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,7 @@ Federated social network with smart contracts.
 - Built on [ActivityPub](https://activitypub.rocks/) protocol.
 - Lightweight.
 - Sign-in with Ethereum.
+- Proving membership with a token.
 - Converting posts into NFTs.
 - More crypto features in the future.
 
diff --git a/src/ethereum/gate.rs b/src/ethereum/gate.rs
new file mode 100644
index 0000000..6ac16f3
--- /dev/null
+++ b/src/ethereum/gate.rs
@@ -0,0 +1,31 @@
+use web3::contract::{Contract, Options};
+
+use crate::config::Config;
+use super::api::connect;
+use super::nft::{MANAGER, load_abi, EthereumError};
+use super::utils::parse_address;
+
+pub async fn is_allowed_user(
+    config: &Config,
+    user_address: &str,
+) -> Result<bool, EthereumError> {
+    let json_rpc_url = config.ethereum_json_rpc_url.as_ref()
+        .ok_or(EthereumError::ImproperlyConfigured)?;
+    let web3 = connect(json_rpc_url)?;
+    let ethereum_config = config.ethereum_contract.as_ref()
+        .ok_or(EthereumError::ImproperlyConfigured)?;
+
+    let manager_abi = load_abi(&config.contract_dir, MANAGER)?;
+    let manager_address = parse_address(&ethereum_config.address)?;
+    let manager = Contract::from_json(
+        web3.eth(),
+        manager_address,
+        &manager_abi,
+    )?;
+    let user_address = parse_address(user_address)?;
+    let result: bool = manager.query(
+        "isAllowedUser", (user_address,),
+        None, Options::default(), None,
+    ).await?;
+    Ok(result)
+}
diff --git a/src/ethereum/mod.rs b/src/ethereum/mod.rs
index 90ba97a..e0ff91f 100644
--- a/src/ethereum/mod.rs
+++ b/src/ethereum/mod.rs
@@ -1,3 +1,4 @@
 mod api;
+pub mod gate;
 pub mod nft;
 pub mod utils;
diff --git a/src/ethereum/nft.rs b/src/ethereum/nft.rs
index 920a642..4ba4612 100644
--- a/src/ethereum/nft.rs
+++ b/src/ethereum/nft.rs
@@ -71,7 +71,7 @@ pub enum EthereumError {
     SigError(#[from] SignatureError),
 }
 
-fn load_abi(
+pub fn load_abi(
     contract_dir: &PathBuf,
     contract_name: &str,
 ) -> Result<Vec<u8>, EthereumError> {
diff --git a/src/mastodon_api/users/views.rs b/src/mastodon_api/users/views.rs
index 9e3f181..427d92a 100644
--- a/src/mastodon_api/users/views.rs
+++ b/src/mastodon_api/users/views.rs
@@ -6,6 +6,7 @@ use actix_web::{
 use crate::config::Config;
 use crate::database::{Pool, get_database_client};
 use crate::errors::{HttpError, ValidationError};
+use crate::ethereum::gate::is_allowed_user;
 use crate::mastodon_api::accounts::types::{Account, AccountCreateData};
 use crate::models::users::queries::{
     is_valid_invite_code,
@@ -35,6 +36,13 @@ pub async fn create_user_view(
             Err(ValidationError("invalid invite code"))?;
         }
     }
+    if config.ethereum_contract.is_some() {
+        let is_allowed = is_allowed_user(&config, &user_data.wallet_address).await
+            .map_err(|_| HttpError::InternalError)?;
+        if !is_allowed {
+            Err(ValidationError("not allowed to sign up"))?;
+        }
+    }
     // Hash password and generate private key
     let password_hash = hash_password(&user_data.password)
         .map_err(|_| HttpError::InternalError)?;