mirror of
https://github.com/luxfi/precompile.git
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zeekay
cd3d40efda
Native EVM precompile for verifying sr25519 signatures, enabling Substrate wallet holders to prove ownership on-chain during migration to EVM-based chains. - CGO path: sr25519-donna C library (37µs/verify, zero alloc) - Pure Go path: ChainSafe/go-schnorrkel fallback (CGO_ENABLED=0) - Address: 0x0A00...0001 (Curves range) - Signing context: "substrate" (Substrate runtime default) - Solidity: ISR25519.sol + SR25519Lib + SubstrateMigration example - Tests: 8 tests with Alice's known Substrate dev key vector
80 lines
3.3 KiB
Solidity
80 lines
3.3 KiB
Solidity
// SPDX-License-Identifier: MIT
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pragma solidity ^0.8.24;
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/// @title ISR25519 — Substrate sr25519 signature verification precompile
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/// @notice Verifies sr25519 (Schnorrkel) signatures with "substrate" signing context.
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/// @dev Used for Substrate → EVM account migration attestation.
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/// Precompile address: 0x0A00000000000000000000000000000000000001
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interface ISR25519 {
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/// @notice Verify an sr25519 signature.
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/// @param publicKey 32-byte Ristretto255 compressed public key (SS58-decoded)
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/// @param signature 64-byte Schnorrkel signature (R || s)
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/// @param message Raw message bytes that were signed
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/// @return valid True if the signature is valid
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function verify(
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bytes32 publicKey,
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bytes calldata signature,
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bytes calldata message
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) external view returns (bool valid);
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}
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/// @title SR25519Lib — Helper library for calling the sr25519 precompile
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library SR25519Lib {
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address internal constant SR25519_PRECOMPILE = 0x0A00000000000000000000000000000000000001;
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/// @notice Low-level staticcall to the sr25519 precompile.
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/// @dev Input format: pubkey(32) || signature(64) || message(N)
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/// Output: 32-byte word, last byte = 1 if valid, 0 if invalid.
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function verify(
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bytes32 publicKey,
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bytes memory signature,
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bytes memory message
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) internal view returns (bool) {
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require(signature.length == 64, "SR25519: sig must be 64 bytes");
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require(message.length > 0, "SR25519: empty message");
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bytes memory input = abi.encodePacked(publicKey, signature, message);
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(bool ok, bytes memory result) = SR25519_PRECOMPILE.staticcall(input);
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if (!ok || result.length < 32) return false;
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return uint256(bytes32(result)) == 1;
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}
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/// @notice Verify or revert.
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function verifyOrRevert(
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bytes32 publicKey,
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bytes memory signature,
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bytes memory message
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) internal view {
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require(verify(publicKey, signature, message), "SR25519: invalid signature");
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}
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}
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/// @title SubstrateMigration — Example migration contract using sr25519 verification
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/// @dev Old Substrate account signs "migrate:<evmAddress>" to prove ownership,
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/// then claims the EVM address on-chain.
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contract SubstrateMigration {
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using SR25519Lib for bytes32;
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mapping(bytes32 => address) public migrations; // sr25519 pubkey → EVM address
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mapping(address => bytes32) public origins; // EVM address → sr25519 pubkey
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event Migrated(bytes32 indexed substratePubKey, address indexed evmAddress);
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/// @notice Claim an EVM address by proving ownership of a Substrate sr25519 key.
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/// @param substratePubKey The 32-byte sr25519 public key
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/// @param signature The 64-byte sr25519 signature over the migration message
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function migrate(bytes32 substratePubKey, bytes calldata signature) external {
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require(migrations[substratePubKey] == address(0), "already migrated");
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// The message that must be signed: "migrate:" + hex-encoded EVM address
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bytes memory message = abi.encodePacked("migrate:", msg.sender);
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substratePubKey.verifyOrRevert(signature, message);
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migrations[substratePubKey] = msg.sender;
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origins[msg.sender] = substratePubKey;
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emit Migrated(substratePubKey, msg.sender);
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}
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}
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