Overview SignatureUtil provides helper functions for working with ECDSA signatures in the deBridge Protocol.
Library Location : contracts/libraries/SignatureUtil.solFunctions recoverSigner function recoverSigner ( bytes32 _hash , bytes memory _signature , uint256 _index ) internal pure returns ( address )
Recovers the signer address from a signature at a specific index.
Message hash that was signed
Concatenated signatures (65 bytes each)
Index of the signature to extract (0-based)
Usage Example Verifying Multiple Signatures
using SignatureUtil for bytes ; bytes32 messageHash = keccak256 ( abi . encodePacked ( submissionId, amount, receiver )); // Signatures are concatenated: [sig0][sig1][sig2]... // Each signature is 65 bytes (r:32, s:32, v:1) bytes memory signatures = /* oracle signatures */ ; uint256 validCount = 0 ; for ( uint256 i = 0 ; i < signatures.length / 65 ; i ++ ) { address signer = signatures. recoverSigner (messageHash, i); if ( isValidOracle (signer)) { validCount ++ ; } } require (validCount >= minConfirmations, "Not enough signatures" );
ECDSA signatures consist of three components:
r : 32 bytes (first part of signature)s : 32 bytes (second part of signature)v : 1 byte (recovery id, 27 or 28)
Total: 65 bytes per signature
// Single signature bytes memory sig = abi . encodePacked (r, s, v); // 65 bytes // Multiple signatures concatenated bytes memory sigs = abi . encodePacked ( r1, s1, v1, // Oracle 1: bytes 0-64 r2, s2, v2, // Oracle 2: bytes 65-129 r3, s3, v3 // Oracle 3: bytes 130-194 );
Security Considerations Always hash messages using keccak256 before signing to prevent signature replay attacks across different message types.
// Include all relevant parameters bytes32 messageHash = keccak256 ( abi . encodePacked ( submissionId, amount, chainIdFrom, chainIdTo, nonce )); // Recover signer address signer = signatures. recoverSigner (messageHash, 0 );
Helper Functions countSignatures function countSignatures ( bytes memory _signatures ) internal pure returns ( uint256 )
Returns the number of signatures in concatenated bytes.
uint256 count = signatures. countSignatures (); // count = signatures.length / 65
SignatureVerifier Contract that uses this library
Oracle Network Learn about oracle signatures
