[near] Add receiver contract (#407)

near: add initial near receiver

Author: Reisen

near/receiver/Cargo.toml

@@ -0,0 +1,40 @@
+[package]
+name            = "pyth-near"
+version         = "0.1.0"
+authors         = ["Pyth Data Association"]
+edition         = "2021"
+description     = "A Pyth Receiver for Near"
+
+[lib]
+name            = "pyth"
+crate-type      = ["cdylib", "lib"]
+
+[dependencies]
+byteorder       = { version = "1.4.3" }
+hex             = { version = "0.4.3" }
+near-sdk        = { version = "4.1.1" }
+p2w-sdk         = { path = "../../third_party/pyth/p2w-sdk/rust" }
+pyth-sdk        = { version = "0.7.0" }
+serde_wormhole  = { git = "https://github.com/wormhole-foundation/wormhole" }
+thiserror       = { version = "1.0.38" }
+wormhole-core   = { git = "https://github.com/wormhole-foundation/wormhole" }
+
+[patch.crates-io]
+serde_wormhole  = { git = "https://github.com/wormhole-foundation/wormhole" }
+
+[dev-dependencies]
+lazy_static     = { version = "1.4.0" }
+serde_json      = { version = "1.0.91" }
+serde           = { version = "1.0.152", features = ["derive"] }
+tokio           = { version = "1.23.0", features = ["full"] }
+serde_wormhole  = { git = "https://github.com/wormhole-foundation/wormhole" }
+workspaces      = { version = "0.7.0" }
+wormhole-core   = { git = "https://github.com/wormhole-foundation/wormhole" }
+
+[profile.release]
+codegen-units   = 1
+opt-level       = 3
+lto             = "fat"
+debug           = false
+panic           = "abort"
+overflow-checks = true

near/receiver/src/error.rs

@@ -0,0 +1,43 @@
+use {
+    near_sdk::{
+        serde::Serialize,
+        FunctionError,
+    },
+    thiserror::Error,
+};
+
+#[derive(Error, Debug, Serialize, FunctionError)]
+#[serde(crate = "near_sdk::serde")]
+pub enum Error {
+    #[error("A hex argument could not be decoded.")]
+    InvalidHex,
+
+    #[error("A VAA could not be deserialized.")]
+    InvalidVaa,
+
+    #[error("A VAA payload could not be deserialized.")]
+    InvalidPayload,
+
+    #[error("Source for attestation is not allowed.")]
+    UnknownSource,
+
+    #[error("Unauthorized Upgrade")]
+    UnauthorizedUpgrade,
+
+    #[error("Insufficient tokens deposited to cover storage.")]
+    InsufficientDeposit,
+
+    #[error("VAA verification failed.")]
+    VaaVerificationFailed,
+
+    #[error("Fee is too large.")]
+    FeeTooLarge,
+}
+
+/// Convert IO errors into Payload errors, the only I/O we do is parsing with `Cursor` so this is a
+/// reasonable conversion.
+impl From<std::io::Error> for Error {
+    fn from(_: std::io::Error) -> Self {
+        Error::InvalidPayload
+    }
+}

near/receiver/src/ext.rs

@@ -0,0 +1,13 @@
+//! This module defines external contract API's that are used by the contract. This includes
+//! Wormhole and perhaps any ancillary Pyth contracts.
+
+use near_sdk::ext_contract;
+
+/// Defines the external contract API we care about for interacting with Wormhole. Note that
+/// Wormhole on NEAR passes VAA's as hex encoded strings so that the explorer can display them in a
+/// clean way. This may require juggling between Vec<u8> and HexString.
+#[ext_contract(ext_wormhole)]
+pub trait Wormhole {
+    /// Returns the Governance Index of the current GuardianSet only if the VAA verifies.
+    fn verify_vaa(&self, vaa: String) -> u32;
+}