auth.go

package gocalibur

import (
	"crypto/ecdsa"
	"math/big"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/holiman/uint256"
)

// CreateAuthorization creates an unsigned EIP-7702 authorization for delegating to Calibur.
func CreateAuthorization(chainID *big.Int, caliburAddr common.Address, nonce uint64) types.SetCodeAuthorization {
	chainID256, _ := uint256.FromBig(chainID)
	return types.SetCodeAuthorization{
		ChainID: *chainID256,
		Address: caliburAddr,
		Nonce:   nonce,
	}
}

// SignAuthorization signs an EIP-7702 authorization.
func SignAuthorization(auth types.SetCodeAuthorization, key *ecdsa.PrivateKey) (types.SetCodeAuthorization, error) {
	return types.SignSetCode(key, auth)
}

// CreateAndSignAuthorization creates and signs an EIP-7702 authorization in one step.
func CreateAndSignAuthorization(key *ecdsa.PrivateKey, chainID *big.Int, caliburAddr common.Address, nonce uint64) (types.SetCodeAuthorization, error) {
	auth := CreateAuthorization(chainID, caliburAddr, nonce)
	return SignAuthorization(auth, key)
}

// SignSecp256k1 signs a SignedBatchedCall with secp256k1 and returns a wrapped signature
// ready for Calibur's execute function. This is the most common signing flow.
//
// Usage:
//
//	domain := gocalibur.CaliburDomain(chainID, userAddr, caliburAddr)
//	sig, err := gocalibur.SignSecp256k1(privateKey, domain, signedCall, nil)
func SignSecp256k1(
	privateKey *ecdsa.PrivateKey,
	domain EIP712Domain,
	signedCall SignedBatchedCall,
	hookData []byte,
) ([]byte, error) {
	digest := ComputeDigest(domain, signedCall)
	sig, err := crypto.Sign(digest[:], privateKey)
	if err != nil {
		return nil, err
	}
	// crypto.Sign returns V as 0 or 1, but Solidity's ecrecover requires 27 or 28
	sig[64] += 27
	return WrapSignature(sig, hookData), nil
}

// GetKeyHashForAddress returns the key hash for a secp256k1 address (root key).
// For root keys, this is keccak256(KeyTypeSecp256k1 || left-padded address).
func GetKeyHashForAddress(addr common.Address) [32]byte {
	return NewSecp256k1Key(addr).KeyHash()
}