don't allow signing deposit messages (#60)

* don't allow signing deposit messages

* Update README.md

---------

Co-authored-by: JasonVranek <jvranek@ucsc.edu>

README.md

@@ -9,7 +9,7 @@ Secure-Signer is a remote signing tool for Ethereum PoS validators, with the fol
 Validator keys are safeguarded in SGX's encrypted memory and the hardware enforces that Secure-Signer can only sign non-slashable messages. This reduces validator risk from slashing either from accidents or if their system is compromised.
 
 
-> **SECURE SIGNER IS UNDER DEVELOPMENT AND SHOULD NOT BE USED FOR PRODUCTION**, unless you know what you are doing. 
+> **SECURE SIGNER IS UNDER DEVELOPMENT**, see [DockerHub](https://hub.docker.com/repository/docker/pufferfi/validator/general) for the latest enclave image.
 
 --- 
 ## API
@@ -22,24 +22,8 @@ Validator keys are safeguarded in SGX's encrypted memory and the hardware enforc
 ## Developers
 - [Developer Documentation](https://pufferfinance.github.io/secure-signer/developers/)
 
---- 
-
-## Roadmap
-- [x] Open source the alpha code
-- [ ] Convert modules into their own open source crates
-- [ ] Standardize the remote-signing specs
-- [ ] Port to other LibOs's
-- [ ] Support non-SGX TEEs
-
-### TODO
-- [ ] API endpoint to GET EIP-3076 SlashProtection database
-- [ ] Code review and audit
-- [ ] Support DCAP remote attestation
-
-### Known Limitations / Issues
-- Only one validator key can be imported per API call
-- **footgun**: if you import an existing validator key, you expose yourself to slashing risk either via stale SlashProtection database or if you run the same key across multiple clients. We recommend [generating fresh keys within Secure-Signer](https://pufferfinance.github.io/secure-signer/running/client#generating-a-validator-key-in-secure-signer) to mitigate this.
-
+## Protocols
+- [Puffer Node Operator Documentation](https://docs.puffer.fi/nodes/requirements)
 
 --- 
 

src/bin/secure-signer.rs

@@ -27,40 +27,43 @@ async fn main() {
         genesis_fork_version,
     };
 
-    let app = axum::Router::new()
-        // Endpoint to check health
-        .route(
-            "/upcheck",
-            axum::routing::get(puffersecuresigner::enclave::shared::handlers::health::handler),
-        )
+    let eth_v1 = axum::Router::new()
         // Endpoint to securely generate and save an ETH sk
         .route(
-            "/eth/v1/keygen/secp256k1",
+            "/keygen/secp256k1",
             axum::routing::post(
                 puffersecuresigner::enclave::secure_signer::handlers::eth_keygen::handler,
             ),
         )
         // Endpoint to securely generate and save a BLS sk
         .route(
-            "/eth/v1/keygen/bls",
+            "/keygen/bls",
             axum::routing::post(
                 puffersecuresigner::enclave::secure_signer::handlers::bls_keygen::handler,
             ),
         )
         // Endpoint to list the pks of all the generated ETH keys
         .route(
-            "/eth/v1/keygen/secp256k1",
+            "/keygen/secp256k1",
             axum::routing::get(
                 puffersecuresigner::enclave::shared::handlers::list_eth_keys::handler,
             ),
         )
         // Endpoint to list all pks of saved bls keys in the enclave
         .route(
-            "/eth/v1/keystores",
+            "/keystores",
             axum::routing::get(
                 puffersecuresigner::enclave::shared::handlers::list_bls_keys::handler,
             ),
+        );
+
+    let app = axum::Router::new()
+        // Endpoint to check health
+        .route(
+            "/upcheck",
+            axum::routing::get(puffersecuresigner::enclave::shared::handlers::health::handler),
         )
+        .nest("/eth/v1", eth_v1)
         // Endpoint to sign DepositData message for registering validator on beacon chain
         .route(
             "/api/v1/eth2/deposit",

src/client/tests/validator.rs

@@ -1,3 +1,8 @@
+use reqwest::StatusCode;
+
+use crate::eth2::eth_types::{
+    BLSPubkey, Bytes32, DepositMessage, DepositRequest, GENESIS_FORK_VERSION,
+};
 use crate::strip_0x_prefix;
 
 use crate::client::traits::ValidatorClientTrait;
@@ -145,3 +150,55 @@ async fn sign_voluntary_exit_message_with_success() {
         .public_key()
         .verify(&sig, root));
 }
+
+#[tokio::test]
+async fn sign_message_deposit_message() {
+    let client = crate::client::ClientBuilder::new().build();
+    let payload = crate::enclave::types::AttestFreshBlsKeyPayload {
+        guardian_pubkeys: vec![
+            hex_to_pubkey("04fad76420abd33cfd92f51f31c47fe678922e476281b21aa8a738bcd56e37a776f678c94592d6aefd17af48b508feb1f27e82da4c0c46a253830e4d8637b3fbaf"),
+            hex_to_pubkey("0x04fad76420abd33cfd92f51f31c47fe678922e476281b21aa8a738bcd56e37a776f678c94592d6aefd17af48b508feb1f27e82da4c0c46a253830e4d8637b3fbaf"),
+            hex_to_pubkey("04fad76420abd33cfd92f51f31c47fe678922e476281b21aa8a738bcd56e37a776f678c94592d6aefd17af48b508feb1f27e82da4c0c46a253830e4d8637b3fbaf"),
+            hex_to_pubkey("0x04fad76420abd33cfd92f51f31c47fe678922e476281b21aa8a738bcd56e37a776f678c94592d6aefd17af48b508feb1f27e82da4c0c46a253830e4d8637b3fbaf")
+        ],
+        withdrawal_credentials: [0; 32],
+        threshold: 3,
+        fork_version: crate::eth2::eth_types::GENESIS_FORK_VERSION,
+        do_remote_attestation: true,
+    };
+    let resp = client
+        .validator
+        .attest_fresh_bls_key(&payload)
+        .await
+        .unwrap();
+
+    let deposit_request = DepositRequest {
+        signingRoot: None,
+        deposit: DepositMessage {
+            pubkey: BLSPubkey::from(
+                hex::decode("04fad76420abd33cfd92f51f31c47fe678922e476281b21aa8a738bcd56e37a776f678c94592d6aefd17af48b508feb1f27e82da4c0c46a253830e4d8637b3fbaf")
+                .unwrap()
+            ),
+            withdrawal_credentials: Bytes32::default(),
+            amount: 0,
+        },
+        genesis_fork_version: GENESIS_FORK_VERSION,
+    };
+    let req = crate::eth2::eth_signing::BLSSignMsg::DEPOSIT(deposit_request);
+
+    let resp = client
+        .validator
+        .client
+        .post(format!(
+            "{}/api/v1/eth2/sign/{}",
+            client.validator.url, resp.bls_pub_key
+        ))
+        .json(&req)
+        .send()
+        .await
+        .unwrap();
+
+    let resp_status = resp.status();
+
+    assert_eq!(resp_status, StatusCode::BAD_REQUEST);
+}

src/enclave/shared/handlers/list_bls_keys_for_vc.rs

@@ -8,10 +8,13 @@ pub async fn handler() -> axum::response::Response {
     match key_management::list_bls_keys() {
         Ok(list_res) => {
             // safely prepend the response with "0x" to match the expected format
-            let list_res = list_res.iter().map(|x| {
-                let stripped: &str = strip_0x_prefix!(x);
-                format!("0x{}", stripped)
-            }).collect::<Vec<String>>();
+            let list_res = list_res
+                .iter()
+                .map(|x| {
+                    let stripped: &str = strip_0x_prefix!(x);
+                    format!("0x{}", stripped)
+                })
+                .collect::<Vec<String>>();
             (axum::http::status::StatusCode::OK, Json(list_res)).into_response()
         }
         Err(e) => {

src/enclave/shared/mod.rs

@@ -8,6 +8,8 @@ use axum::{
 use log::{error, info};
 use sha3::Digest;
 
+use crate::eth2::eth_signing::BLSSignMsg;
+
 /// Signs the specific type of request
 /// Maintains compatibility with https://consensys.github.io/web3signer/web3signer-eth2.html#tag/Signing
 pub fn sign_validator_message(
@@ -17,6 +19,14 @@ pub fn sign_validator_message(
 ) -> axum::response::Response {
     info!("secure_sign_bls()");
 
+    if let BLSSignMsg::DEPOSIT(_) = req {
+        return (
+            axum::http::status::StatusCode::BAD_REQUEST,
+            format!("Signing deposit message not allowed"),
+        )
+            .into_response();
+    }
+
     // Sanitize the input bls_pk_hex
     let bls_pk_hex = match crate::crypto::bls_keys::sanitize_bls_pk_hex(&bls_pk_hex) {
         Ok(pk) => pk,