feat: signed voucher handling

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
-members = ["common", "config", "service", "tap-agent"]
+members = ["common", "config", "dips", "service", "tap-agent"]
 resolver = "2"
 
 [profile.dev.package."*"]
@@ -19,6 +19,7 @@ anyhow = { version = "1.0.72" }
 thiserror = "1.0.49"
 async-trait = "0.1.72"
 eventuals = "0.6.7"
+base64 = "0.22.1"
 reqwest = { version = "0.12", features = [
     "charset",
     "h2",

common/src/indexer_service/http/config.rs

@@ -42,6 +42,13 @@ pub struct IndexerServiceConfig {
     pub escrow_subgraph: SubgraphConfig,
     pub graph_network: GraphNetworkConfig,
     pub tap: TapConfig,
+    pub dips: IndexerDipsConfig,
+}
+
+#[derive(Debug, Deserialize, Serialize, Clone)]
+pub struct IndexerDipsConfig {
+    pub expected_payee: String,
+    pub allowed_payers: Vec<String>,
 }
 
 #[derive(Clone, Debug, Deserialize, Serialize)]

common/src/indexer_service/http/mod.rs

@@ -8,8 +8,8 @@ mod static_subgraph;
 mod tap_receipt_header;
 
 pub use config::{
-    DatabaseConfig, GraphNetworkConfig, GraphNodeConfig, IndexerConfig, IndexerServiceConfig,
-    ServerConfig, SubgraphConfig, TapConfig,
+    DatabaseConfig, GraphNetworkConfig, GraphNodeConfig, IndexerConfig, IndexerDipsConfig,
+    IndexerServiceConfig, ServerConfig, SubgraphConfig, TapConfig,
 };
 pub use indexer_service::{
     AttestationOutput, IndexerService, IndexerServiceImpl, IndexerServiceOptions,

config/src/config.rs

@@ -31,6 +31,7 @@ pub struct Config {
     pub blockchain: BlockchainConfig,
     pub service: ServiceConfig,
     pub tap: TapConfig,
+    pub dips: DipsConfig,
 }
 
 // Newtype wrapping Config to be able use serde_ignored with Figment
@@ -307,6 +308,13 @@ pub struct TapConfig {
     pub sender_aggregator_endpoints: HashMap<Address, Url>,
 }
 
+#[derive(Debug, Deserialize)]
+#[cfg_attr(test, derive(PartialEq))]
+pub struct DipsConfig {
+    pub expected_payee: String,
+    pub allowed_payers: Vec<String>,
+}
+
 impl TapConfig {
     pub fn get_trigger_value(&self) -> u128 {
         let grt_wei = self.max_amount_willing_to_lose_grt.get_value();

dips/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "indexer-dips"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+alloy-core = "0.8.5"
+alloy-primitives = { version = "0.8.5", default-features = true, features = ["rlp"]}
+alloy-sol-types = "0.8.5"
+alloy-signer = "0.4.2"
+alloy-rlp = "0.3.8"
+
+[dev-dependencies]
+alloy-signer-local = "0.4.2"

dips/src/lib.rs

@@ -0,0 +1,173 @@
+// Copyright 2023-, Edge & Node, GraphOps, and Semiotic Labs.
+// SPDX-License-Identifier: Apache-2.0
+
+use std::str::FromStr;
+
+pub use alloy_core;
+pub use alloy_rlp;
+pub use alloy_signer;
+pub use alloy_sol_types;
+
+use alloy_core::primitives::Address;
+use alloy_rlp::{RlpDecodable, RlpEncodable};
+use alloy_signer::Signature;
+use alloy_sol_types::{sol, SolStruct};
+
+sol! {
+    // EIP712 encoded bytes, ABI - ethers
+    #[derive(Debug, RlpEncodable, RlpDecodable, PartialEq)]
+    struct SignedIndexingAgreementVoucher {
+        IndexingAgreementVoucher voucher;
+        bytes signature;
+    }
+
+    #[derive(Debug, RlpEncodable, RlpDecodable, PartialEq)]
+    struct IndexingAgreementVoucher {
+      // should coincide with signer
+        address payer;
+        // should coincide with indexer
+        address payee;
+         // data service that will initiate payment collection
+        address service;
+        // initial indexing amount max
+        uint256 maxInitialAmount;
+        uint256 maxOngoingAmountPerEpoch;
+        // time to accept the agreement, intended to be on the order
+        // of hours or mins
+        uint64 deadline;
+        uint32 maxEpochsPerCollection;
+        uint32 minEpochsPerCollection;
+        // after which the agreement is complete
+        uint32 durationEpochs;
+        bytes metadata;
+    }
+
+    // the vouchers are generic to each data service, in the case of subgraphs this is an ABI-encoded SubgraphIndexingVoucherMetadata
+    #[derive(Debug, RlpEncodable, RlpDecodable, PartialEq)]
+    struct SubgraphIndexingVoucherMetadata {
+        uint256 pricePerBlock; // wei GRT
+        bytes32 protocolNetwork; // eip199:1 format
+        // differentiate based on indexed chain
+        bytes32 chainId; // eip199:1 format
+    }
+}
+
+impl SignedIndexingAgreementVoucher {
+    // TODO: Validate all values, maybe return a useful error on failure.
+    pub fn is_valid(
+        &self,
+        expected_payee: &Address,
+        allowed_payers: impl AsRef<[Address]>,
+    ) -> bool {
+        let sig = match Signature::from_str(&self.signature.to_string()) {
+            Ok(s) => s,
+            Err(_) => return false,
+        };
+
+        let payer = sig
+            .recover_address_from_msg(self.voucher.eip712_hash_struct())
+            .unwrap();
+
+        if allowed_payers.as_ref().is_empty()
+            || !allowed_payers.as_ref().iter().any(|addr| addr.eq(&payer))
+        {
+            return false;
+        }
+
+        if !self.voucher.payee.eq(expected_payee) {
+            return false;
+        }
+
+        true
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use alloy_core::primitives::{Address, FixedBytes, U256};
+    use alloy_signer::SignerSync;
+    use alloy_signer_local::PrivateKeySigner;
+    use alloy_sol_types::SolStruct;
+
+    use crate::{
+        IndexingAgreementVoucher, SignedIndexingAgreementVoucher, SubgraphIndexingVoucherMetadata,
+    };
+
+    #[test]
+    fn voucher_signature_verification() {
+        let payee = PrivateKeySigner::random();
+        let payee_addr = payee.address();
+        let payer = PrivateKeySigner::random();
+        let payer_addr = payer.address();
+
+        let metadata = SubgraphIndexingVoucherMetadata {
+            pricePerBlock: U256::from(10000_u64),
+            protocolNetwork: FixedBytes::left_padding_from("arbitrum-one".as_bytes()),
+            chainId: FixedBytes::left_padding_from("mainnet".as_bytes()),
+        };
+
+        let voucher = IndexingAgreementVoucher {
+            payer: payer_addr,
+            payee: payee.address(),
+            service: Address(FixedBytes::ZERO),
+            maxInitialAmount: U256::from(10000_u64),
+            maxOngoingAmountPerEpoch: U256::from(10000_u64),
+            deadline: 1000,
+            maxEpochsPerCollection: 1000,
+            minEpochsPerCollection: 1000,
+            durationEpochs: 1000,
+            metadata: metadata.eip712_hash_struct().to_owned().into(),
+        };
+
+        let signed = SignedIndexingAgreementVoucher {
+            voucher: voucher.clone(),
+            signature: payer
+                .sign_message_sync(voucher.eip712_hash_struct().as_slice())
+                .unwrap()
+                .as_bytes()
+                .into(),
+        };
+
+        assert!(signed.is_valid(&payee_addr, vec![]));
+        assert!(signed.is_valid(&payee_addr, vec![payer_addr]));
+    }
+
+    #[test]
+    fn check_voucher_modified() {
+        let payee = PrivateKeySigner::random();
+        let payee_addr = payee.address();
+        let payer = PrivateKeySigner::random();
+        let payer_addr = payer.address();
+
+        let metadata = SubgraphIndexingVoucherMetadata {
+            pricePerBlock: U256::from(10000_u64),
+            protocolNetwork: FixedBytes::left_padding_from("arbitrum-one".as_bytes()),
+            chainId: FixedBytes::left_padding_from("mainnet".as_bytes()),
+        };
+
+        let voucher = IndexingAgreementVoucher {
+            payer: payer_addr,
+            payee: payee_addr,
+            service: Address(FixedBytes::ZERO),
+            maxInitialAmount: U256::from(10000_u64),
+            maxOngoingAmountPerEpoch: U256::from(10000_u64),
+            deadline: 1000,
+            maxEpochsPerCollection: 1000,
+            minEpochsPerCollection: 1000,
+            durationEpochs: 1000,
+            metadata: metadata.eip712_hash_struct().to_owned().into(),
+        };
+
+        let mut signed = SignedIndexingAgreementVoucher {
+            voucher: voucher.clone(),
+            signature: payer
+                .sign_message_sync(voucher.eip712_hash_struct().as_slice())
+                .unwrap()
+                .as_bytes()
+                .into(),
+        };
+        signed.voucher.service = Address::repeat_byte(9);
+
+        assert!(signed.is_valid(&payee_addr, vec![payer_addr]));
+    }
+}

service/Cargo.toml

@@ -9,6 +9,7 @@ license = "Apache-2.0"
 [dependencies]
 indexer-common = { path = "../common" }
 indexer-config = { path = "../config" }
+indexer-dips = { path = "../dips" }
 anyhow = { workspace = true }
 prometheus = { workspace = true }
 reqwest = { workspace = true }
@@ -27,10 +28,12 @@ build-info.workspace = true
 lazy_static.workspace = true
 async-graphql = { version = "7.0.11", default-features = false }
 async-graphql-axum = "7.0.11"
+base64.workspace = true
 graphql = { git = "https://github.com/edgeandnode/toolshed", tag = "graphql-v0.3.0" }
 
 [dev-dependencies]
 hex-literal = "0.4.1"
+alloy-signer-local = "0.4.2"
 
 [build-dependencies]
 build-info-build = { version = "0.0.38", default-features = false }

service/src/config.rs

@@ -4,8 +4,8 @@
 use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};
 
 use indexer_common::indexer_service::http::{
-    DatabaseConfig, GraphNetworkConfig, GraphNodeConfig, IndexerConfig, IndexerServiceConfig,
-    ServerConfig, SubgraphConfig, TapConfig,
+    DatabaseConfig, GraphNetworkConfig, GraphNodeConfig, IndexerConfig, IndexerDipsConfig,
+    IndexerServiceConfig, ServerConfig, SubgraphConfig, TapConfig,
 };
 use indexer_config::Config as MainConfig;
 use serde::{Deserialize, Serialize};
@@ -77,6 +77,10 @@ impl From<MainConfig> for Config {
                 timestamp_error_tolerance: value.tap.rav_request.timestamp_buffer_secs.as_secs(),
                 receipt_max_value: value.service.tap.max_receipt_value_grt.get_value(),
             },
+            dips: IndexerDipsConfig {
+                expected_payee: value.dips.expected_payee,
+                allowed_payers: value.dips.allowed_payers,
+            },
         })
     }
 }

service/src/database/dips.rs

@@ -18,6 +18,7 @@ pub trait AgreementStore: Sync + Send {
     async fn cancel_agreement(&self, signature: String) -> anyhow::Result<String>;
 }
 
+#[derive(Default)]
 pub struct InMemoryAgreementStore {
     pub data: tokio::sync::RwLock<HashMap<String, Agreement>>,
 }