package hd import ( "fmt" "github.com/pkg/errors" "github.com/btcsuite/btcd/chaincfg" "github.com/btcsuite/btcutil/hdkeychain" "github.com/tyler-smith/go-bip39" ethaccounts "github.com/ethereum/go-ethereum/accounts" ethcrypto "github.com/ethereum/go-ethereum/crypto" tmcrypto "github.com/tendermint/tendermint/crypto" "github.com/cosmos/cosmos-sdk/crypto/keys" "github.com/cosmos/ethermint/crypto/ethsecp256k1" ) const ( // EthSecp256k1 defines the ECDSA secp256k1 used on Ethereum EthSecp256k1 = keys.SigningAlgo(ethsecp256k1.KeyType) ) // SupportedAlgorithms defines the list of signing algorithms used on Ethermint: // - eth_secp256k1 (Ethereum) // - secp256k1 (Tendermint) var SupportedAlgorithms = []keys.SigningAlgo{EthSecp256k1, keys.Secp256k1} // EthSecp256k1Options defines a keys options for the ethereum Secp256k1 curve. func EthSecp256k1Options() []keys.KeybaseOption { return []keys.KeybaseOption{ keys.WithKeygenFunc(EthermintKeygenFunc), keys.WithDeriveFunc(DeriveKey), keys.WithSupportedAlgos(SupportedAlgorithms), keys.WithSupportedAlgosLedger(SupportedAlgorithms), } } func DeriveKey(mnemonic, bip39Passphrase, hdPath string, algo keys.SigningAlgo) ([]byte, error) { switch algo { case keys.Secp256k1: return keys.StdDeriveKey(mnemonic, bip39Passphrase, hdPath, algo) case EthSecp256k1: return DeriveSecp256k1(mnemonic, bip39Passphrase, hdPath) default: return nil, errors.Wrap(keys.ErrUnsupportedSigningAlgo, string(algo)) } } // EthermintKeygenFunc is the key generation function to generate secp256k1 ToECDSA // from ethereum. func EthermintKeygenFunc(bz []byte, algo keys.SigningAlgo) (tmcrypto.PrivKey, error) { if algo != EthSecp256k1 { return nil, fmt.Errorf("signing algorithm must be %s, got %s", EthSecp256k1, algo) } return ethsecp256k1.PrivKey(bz), nil } // DeriveSecp256k1 derives and returns the eth_secp256k1 private key for the given mnemonic and HD path. func DeriveSecp256k1(mnemonic, bip39Passphrase, path string) ([]byte, error) { hdpath, err := ethaccounts.ParseDerivationPath(path) if err != nil { return nil, err } seed, err := bip39.NewSeedWithErrorChecking(mnemonic, bip39Passphrase) if err != nil { return nil, err } masterKey, err := hdkeychain.NewMaster(seed, &chaincfg.MainNetParams) if err != nil { return nil, err } key := masterKey for _, n := range hdpath { key, err = key.Child(n) if err != nil { return nil, err } } privateKey, err := key.ECPrivKey() if err != nil { return nil, err } privateKeyECDSA := privateKey.ToECDSA() derivedKey := ethsecp256k1.PrivKey(ethcrypto.FromECDSA(privateKeyECDSA)) return derivedKey, nil }