ic-web3 0.1.7

//! Signing capabilities and utilities.

use crate::types::H256;

/// Error during signing.
#[derive(Debug, derive_more::Display, PartialEq, Clone)]
pub enum SigningError {
    /// A message to sign is invalid. Has to be a non-zero 32-bytes slice.
    #[display(fmt = "Message has to be a non-zero 32-bytes slice.")]
    InvalidMessage,
}
impl std::error::Error for SigningError {}

/// Error during sender recovery.
#[derive(Debug, derive_more::Display, PartialEq, Clone)]
pub enum RecoveryError {
    /// A message to recover is invalid. Has to be a non-zero 32-bytes slice.
    #[display(fmt = "Message has to be a non-zero 32-bytes slice.")]
    InvalidMessage,
    /// A signature is invalid and the sender could not be recovered.
    #[display(fmt = "Signature is invalid (check recovery id).")]
    InvalidSignature,
}
impl std::error::Error for RecoveryError {}

// #[cfg(feature = "signing")]
// pub use feature_gated::*;

// #[cfg(feature = "signing")]
// mod feature_gated {
//     use super::*;
//     use crate::types::Address;
//     use once_cell::sync::Lazy;
//     pub(crate) use secp256k1::SecretKey;
//     use secp256k1::{
//         ecdsa::{RecoverableSignature, RecoveryId},
//         All, Message, PublicKey, Secp256k1,
//     };
//     use std::ops::Deref;

//     static CONTEXT: Lazy<Secp256k1<All>> = Lazy::new(Secp256k1::new);

//     /// A trait representing ethereum-compatible key with signing capabilities.
//     ///
//     /// The purpose of this trait is to prevent leaking `secp256k1::SecretKey` struct
//     /// in stack or memory.
//     /// To use secret keys securely, they should be wrapped in a struct that prevents
//     /// leaving copies in memory (both when it's moved or dropped). Please take a look
//     /// at:
//     /// - https://github.com/graphprotocol/solidity-bindgen/blob/master/solidity-bindgen/src/secrets.rs
//     /// - or https://crates.io/crates/zeroize
//     /// if you care enough about your secrets to be used securely.
//     ///
//     /// If it's enough to pass a reference to `SecretKey` (lifetimes) than you can use `SecretKeyRef`
//     /// wrapper.
//     pub trait Key {
//         /// Sign given message and include chain-id replay protection.
//         ///
//         /// When a chain ID is provided, the `Signature`'s V-value will have chain replay
//         /// protection added (as per EIP-155). Otherwise, the V-value will be in
//         /// 'Electrum' notation.
//         fn sign(&self, message: &[u8], chain_id: Option<u64>) -> Result<Signature, SigningError>;

//         /// Sign given message without manipulating V-value; used for typed transactions
//         /// (AccessList and EIP-1559)
//         fn sign_message(&self, message: &[u8]) -> Result<Signature, SigningError>;

//         /// Get public address that this key represents.
//         fn address(&self) -> Address;
//     }

//     /// A `SecretKey` reference wrapper.
//     ///
//     /// A wrapper around `secp256k1::SecretKey` reference, which enables it to be used in methods expecting
//     /// `Key` capabilities.
//     pub struct SecretKeyRef<'a> {
//         pub(super) key: &'a SecretKey,
//     }

//     impl<'a> SecretKeyRef<'a> {
//         /// A simple wrapper around a reference to `SecretKey` which allows it to be usable for signing.
//         pub fn new(key: &'a SecretKey) -> Self {
//             Self { key }
//         }
//     }

//     impl<'a> From<&'a SecretKey> for SecretKeyRef<'a> {
//         fn from(key: &'a SecretKey) -> Self {
//             Self::new(key)
//         }
//     }

//     impl<'a> Deref for SecretKeyRef<'a> {
//         type Target = SecretKey;

//         fn deref(&self) -> &Self::Target {
//             self.key
//         }
//     }

//     impl<T: Deref<Target = SecretKey>> Key for T {
//         fn sign(&self, message: &[u8], chain_id: Option<u64>) -> Result<Signature, SigningError> {
//             let message = Message::from_slice(message).map_err(|_| SigningError::InvalidMessage)?;
//             let (recovery_id, signature) = CONTEXT.sign_ecdsa_recoverable(&message, self).serialize_compact();

//             let standard_v = recovery_id.to_i32() as u64;
//             let v = if let Some(chain_id) = chain_id {
//                 // When signing with a chain ID, add chain replay protection.
//                 standard_v + 35 + chain_id * 2
//             } else {
//                 // Otherwise, convert to 'Electrum' notation.
//                 standard_v + 27
//             };
//             let r = H256::from_slice(&signature[..32]);
//             let s = H256::from_slice(&signature[32..]);

//             Ok(Signature { v, r, s })
//         }

//         fn sign_message(&self, message: &[u8]) -> Result<Signature, SigningError> {
//             let message = Message::from_slice(message).map_err(|_| SigningError::InvalidMessage)?;
//             let (recovery_id, signature) = CONTEXT.sign_ecdsa_recoverable(&message, self).serialize_compact();

//             let v = recovery_id.to_i32() as u64;
//             let r = H256::from_slice(&signature[..32]);
//             let s = H256::from_slice(&signature[32..]);

//             Ok(Signature { v, r, s })
//         }

//         fn address(&self) -> Address {
//             secret_key_address(self)
//         }
//     }

//     /// Recover a sender, given message and the signature.
//     ///
//     /// Signature and `recovery_id` can be obtained from `types::Recovery` type.
//     pub fn recover(message: &[u8], signature: &[u8], recovery_id: i32) -> Result<Address, RecoveryError> {
//         let message = Message::from_slice(message).map_err(|_| RecoveryError::InvalidMessage)?;
//         let recovery_id = RecoveryId::from_i32(recovery_id).map_err(|_| RecoveryError::InvalidSignature)?;
//         let signature =
//             RecoverableSignature::from_compact(signature, recovery_id).map_err(|_| RecoveryError::InvalidSignature)?;
//         let public_key = CONTEXT
//             .recover_ecdsa(&message, &signature)
//             .map_err(|_| RecoveryError::InvalidSignature)?;

//         Ok(public_key_address(&public_key))
//     }

//     /// Gets the address of a public key.
//     ///
//     /// The public address is defined as the low 20 bytes of the keccak hash of
//     /// the public key. Note that the public key returned from the `secp256k1`
//     /// crate is 65 bytes long, that is because it is prefixed by `0x04` to
//     /// indicate an uncompressed public key; this first byte is ignored when
//     /// computing the hash.
//     pub(crate) fn public_key_address(public_key: &PublicKey) -> Address {
//         let public_key = public_key.serialize_uncompressed();

//         debug_assert_eq!(public_key[0], 0x04);
//         let hash = keccak256(&public_key[1..]);

//         Address::from_slice(&hash[12..])
//     }

//     /// Gets the public address of a private key.
//     pub(crate) fn secret_key_address(key: &SecretKey) -> Address {
//         let secp = &*CONTEXT;
//         let public_key = PublicKey::from_secret_key(secp, key);
//         public_key_address(&public_key)
//     }
// }

/// A struct that represents the components of a secp256k1 signature.
pub struct Signature {
    /// V component in electrum format with chain-id replay protection.
    pub v: u64,
    /// R component of the signature.
    pub r: H256,
    /// S component of the signature.
    pub s: H256,
}

/// Compute the Keccak-256 hash of input bytes.
pub fn keccak256(bytes: &[u8]) -> [u8; 32] {
    use tiny_keccak::{Hasher, Keccak};
    let mut output = [0u8; 32];
    let mut hasher = Keccak::v256();
    hasher.update(bytes);
    hasher.finalize(&mut output);
    output
}

// /// Result of the name hash algotithm.
// pub type NameHash = [u8; 32];

// /// Compute the hash of a domain name using the namehash algorithm.
// ///
// /// [Specification](https://docs.ens.domains/contract-api-reference/name-processing#hashing-names)
// pub fn namehash(name: &str) -> NameHash {
//     let mut node = [0u8; 32];

//     if name.is_empty() {
//         return node;
//     }

//     let mut labels: Vec<&str> = name.split('.').collect();

//     labels.reverse();

//     for label in labels.iter() {
//         let label_hash = keccak256(label.as_bytes());

//         node = keccak256(&[node, label_hash].concat());
//     }

//     node
// }

/// Hash a message according to EIP-191.
///
/// The data is a UTF-8 encoded string and will enveloped as follows:
/// `"\x19Ethereum Signed Message:\n" + message.length + message` and hashed
/// using keccak256.
pub fn hash_message<S>(message: S) -> H256
where
    S: AsRef<[u8]>,
{
    let message = message.as_ref();

    let mut eth_message = format!("\x19Ethereum Signed Message:\n{}", message.len()).into_bytes();
    eth_message.extend_from_slice(message);

    keccak256(&eth_message).into()
}

// #[cfg(test)]
// mod tests {
//     use super::*;

//     //See -> https://eips.ethereum.org/EIPS/eip-137 for test cases

//     #[test]
//     fn name_hash_empty() {
//         let input = "";

//         let result = namehash(input);

//         let expected = [0u8; 32];

//         assert_eq!(expected, result);
//     }

//     #[test]
//     fn name_hash_eth() {
//         let input = "eth";

//         let result = namehash(input);

//         let expected = [
//             0x93, 0xcd, 0xeb, 0x70, 0x8b, 0x75, 0x45, 0xdc, 0x66, 0x8e, 0xb9, 0x28, 0x01, 0x76, 0x16, 0x9d, 0x1c, 0x33,
//             0xcf, 0xd8, 0xed, 0x6f, 0x04, 0x69, 0x0a, 0x0b, 0xcc, 0x88, 0xa9, 0x3f, 0xc4, 0xae,
//         ];

//         assert_eq!(expected, result);
//     }

//     #[test]
//     fn name_hash_foo_eth() {
//         let input = "foo.eth";

//         let result = namehash(input);

//         let expected = [
//             0xde, 0x9b, 0x09, 0xfd, 0x7c, 0x5f, 0x90, 0x1e, 0x23, 0xa3, 0xf1, 0x9f, 0xec, 0xc5, 0x48, 0x28, 0xe9, 0xc8,
//             0x48, 0x53, 0x98, 0x01, 0xe8, 0x65, 0x91, 0xbd, 0x98, 0x01, 0xb0, 0x19, 0xf8, 0x4f,
//         ];

//         assert_eq!(expected, result);
//     }
// }