feat: add blockchain API provider

relay_rpc/src/auth/cacao.rs

@@ -2,7 +2,7 @@ use {
     self::{
         header::Header,
         payload::Payload,
-        signature::{GetRpcUrl, Signature},
+        signature::{eip1271::get_rpc_url::GetRpcUrl, Signature},
     },
     core::fmt::Debug,
     serde::{Deserialize, Serialize},

relay_rpc/src/auth/cacao/signature/eip1271/blockchain_api.rs

@@ -0,0 +1,58 @@
+use {super::get_rpc_url::GetRpcUrl, crate::domain::ProjectId, url::Url};
+
+// https://github.com/WalletConnect/blockchain-api/blob/master/SUPPORTED_CHAINS.md
+const SUPPORTED_CHAINS: [&str; 26] = [
+    "eip155:1",
+    "eip155:5",
+    "eip155:11155111",
+    "eip155:10",
+    "eip155:420",
+    "eip155:42161",
+    "eip155:421613",
+    "eip155:137",
+    "eip155:80001",
+    "eip155:1101",
+    "eip155:42220",
+    "eip155:1313161554",
+    "eip155:1313161555",
+    "eip155:56",
+    "eip155:56",
+    "eip155:43114",
+    "eip155:43113",
+    "eip155:324",
+    "eip155:280",
+    "near",
+    "eip155:100",
+    "solana:4sgjmw1sunhzsxgspuhpqldx6wiyjntz",
+    "eip155:8453",
+    "eip155:84531",
+    "eip155:7777777",
+    "eip155:999",
+];
+
+pub struct BlockchainApiProvider {
+    project_id: ProjectId,
+}
+
+impl BlockchainApiProvider {
+    pub fn new(project_id: ProjectId) -> Self {
+        Self { project_id }
+    }
+}
+
+impl GetRpcUrl for BlockchainApiProvider {
+    fn get_rpc_url(&self, chain_id: String) -> Option<Url> {
+        if SUPPORTED_CHAINS.contains(&chain_id.as_str()) {
+            Some(
+                format!(
+                    "https://rpc.walletconnect.com/v1?chainId={chain_id}&projectId={}",
+                    self.project_id
+                )
+                .parse()
+                .expect("Provider URL should be valid"),
+            )
+        } else {
+            None
+        }
+    }
+}

relay_rpc/src/auth/cacao/signature/eip1271/get_rpc_url.rs

@@ -0,0 +1,5 @@
+use url::Url;
+
+pub trait GetRpcUrl {
+    fn get_rpc_url(&self, chain_id: String) -> Option<Url>;
+}

relay_rpc/src/auth/cacao/signature/eip1271/mod.rs

@@ -0,0 +1,98 @@
+use {
+    super::CacaoError,
+    alloy_primitives::{Address, FixedBytes},
+    alloy_providers::provider::{Provider, TempProvider},
+    alloy_rpc_types::{CallInput, CallRequest},
+    alloy_sol_types::{sol, SolCall},
+    alloy_transport_http::Http,
+    url::Url,
+};
+
+pub mod blockchain_api;
+pub mod get_rpc_url;
+
+pub const EIP1271: &str = "eip1271";
+
+// https://eips.ethereum.org/EIPS/eip-1271
+const MAGIC_VALUE: u32 = 0x1626ba7e;
+sol! {
+    function isValidSignature(
+        bytes32 _hash,
+        bytes memory _signature)
+        public
+        view
+        returns (bytes4 magicValue);
+}
+
+pub async fn verify_eip1271(
+    signature: Vec<u8>,
+    address: Address,
+    hash: &[u8; 32],
+    provider: Url,
+) -> Result<bool, CacaoError> {
+    let provider = Provider::new(Http::new(provider));
+
+    let call_request = CallRequest {
+        to: Some(address),
+        input: CallInput::new(
+            isValidSignatureCall {
+                _hash: FixedBytes::from(hash),
+                _signature: signature,
+            }
+            .abi_encode()
+            .into(),
+        ),
+        ..Default::default()
+    };
+
+    let result = provider.call(call_request, None).await.map_err(|e| {
+        if let Some(error_response) = e.as_error_resp() {
+            if error_response.message.starts_with("execution reverted:") {
+                CacaoError::Verification
+            } else {
+                CacaoError::Eip1271Internal(e)
+            }
+        } else {
+            CacaoError::Eip1271Internal(e)
+        }
+    })?;
+
+    if result[..4] == MAGIC_VALUE.to_be_bytes().to_vec() {
+        Ok(true)
+    } else {
+        Err(CacaoError::Verification)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use {
+        super::*,
+        crate::auth::cacao::signature::{eip191::eip191_bytes, strip_hex_prefix},
+        alloy_primitives::address,
+        sha3::{Digest, Keccak256},
+    };
+
+    // Manual test. Paste address, signature, message, and project ID to verify
+    // function
+    #[tokio::test]
+    #[ignore]
+    async fn test_eip1271() {
+        let address = address!("AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA");
+        let signature = "xxx";
+        let signature = data_encoding::HEXLOWER_PERMISSIVE
+            .decode(strip_hex_prefix(signature).as_bytes())
+            .map_err(|_| CacaoError::Verification)
+            .unwrap();
+        let message = "xxx";
+        let hash = &Keccak256::new_with_prefix(eip191_bytes(message)).finalize()[..]
+            .try_into()
+            .unwrap();
+        let provider = "https://rpc.walletconnect.com/v1?chainId=eip155:1&projectId=xxx"
+            .parse()
+            .unwrap();
+        assert!(verify_eip1271(signature, address, hash, provider)
+            .await
+            .unwrap());
+    }
+}