laconicd-deprecated/crypto/ethsecp256k1/ethsecp256k1.go
Federico Kunze 65453e4aa0
rpc, evm: secure tx signing (#20)
* rpc, evm: secure signing

* evm, ante: test signer

* tests
2021-05-12 09:08:31 -04:00

207 lines
6.0 KiB
Go

package ethsecp256k1
import (
"bytes"
"crypto/ecdsa"
"crypto/subtle"
"fmt"
ethcrypto "github.com/ethereum/go-ethereum/crypto"
"github.com/cosmos/cosmos-sdk/codec"
cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
tmcrypto "github.com/tendermint/tendermint/crypto"
)
const (
// PrivKeySize defines the size of the PrivKey bytes
PrivKeySize = 32
// PubKeySize defines the size of the PubKey bytes
PubKeySize = 33
// KeyType is the string constant for the Secp256k1 algorithm
KeyType = "eth_secp256k1"
)
// Amino encoding names
const (
// PrivKeyName defines the amino encoding name for the EthSecp256k1 private key
PrivKeyName = "ethermint/PrivKeyEthSecp256k1"
// PubKeyName defines the amino encoding name for the EthSecp256k1 public key
PubKeyName = "ethermint/PubKeyEthSecp256k1"
)
// ----------------------------------------------------------------------------
// secp256k1 Private Key
var (
_ cryptotypes.PrivKey = &PrivKey{}
_ codec.AminoMarshaler = &PrivKey{}
)
// GenerateKey generates a new random private key. It returns an error upon
// failure.
func GenerateKey() (*PrivKey, error) {
priv, err := ethcrypto.GenerateKey()
if err != nil {
return nil, err
}
return &PrivKey{
Key: ethcrypto.FromECDSA(priv),
}, nil
}
// Bytes returns the byte representation of the ECDSA Private Key.
func (privKey PrivKey) Bytes() []byte {
return privKey.Key
}
// PubKey returns the ECDSA private key's public key.
func (privKey PrivKey) PubKey() cryptotypes.PubKey {
ecdsaPrivKey := privKey.ToECDSA()
return &PubKey{
Key: ethcrypto.CompressPubkey(&ecdsaPrivKey.PublicKey),
}
}
// Equals returns true if two ECDSA private keys are equal and false otherwise.
func (privKey PrivKey) Equals(other cryptotypes.LedgerPrivKey) bool {
return privKey.Type() == other.Type() && subtle.ConstantTimeCompare(privKey.Bytes(), other.Bytes()) == 1
}
// Type returns eth_secp256k1
func (privKey PrivKey) Type() string {
return KeyType
}
// MarshalAmino overrides Amino binary marshalling.
func (privKey PrivKey) MarshalAmino() ([]byte, error) {
return privKey.Key, nil
}
// UnmarshalAmino overrides Amino binary marshalling.
func (privKey *PrivKey) UnmarshalAmino(bz []byte) error {
if len(bz) != PrivKeySize {
return fmt.Errorf("invalid privkey size, expected %d got %d", PrivKeySize, len(bz))
}
privKey.Key = bz
return nil
}
// MarshalAminoJSON overrides Amino JSON marshalling.
func (privKey PrivKey) MarshalAminoJSON() ([]byte, error) {
// When we marshal to Amino JSON, we don't marshal the "key" field itself,
// just its contents (i.e. the key bytes).
return privKey.MarshalAmino()
}
// UnmarshalAminoJSON overrides Amino JSON marshalling.
func (privKey *PrivKey) UnmarshalAminoJSON(bz []byte) error {
return privKey.UnmarshalAmino(bz)
}
// Sign creates a recoverable ECDSA signature on the secp256k1 curve over the
// provided hash of the message. The produced signature is 65 bytes
// where the last byte contains the recovery ID.
func (privKey PrivKey) Sign(digestBz []byte) ([]byte, error) {
if len(digestBz) != ethcrypto.DigestLength {
digestBz = ethcrypto.Keccak256Hash(digestBz).Bytes()
}
return ethcrypto.Sign(digestBz, privKey.ToECDSA())
}
// ToECDSA returns the ECDSA private key as a reference to ecdsa.PrivateKey type.
// The function will panic if the private key is invalid.
func (privKey PrivKey) ToECDSA() *ecdsa.PrivateKey {
key, err := ethcrypto.ToECDSA(privKey.Bytes())
if err != nil {
panic(err)
}
return key
}
// ----------------------------------------------------------------------------
// secp256k1 Public Key
var (
_ cryptotypes.PubKey = &PubKey{}
_ codec.AminoMarshaler = &PubKey{}
)
// Address returns the address of the ECDSA public key.
// The function will panic if the public key is invalid.
func (pubKey PubKey) Address() tmcrypto.Address {
pubk, err := ethcrypto.DecompressPubkey(pubKey.Key)
if err != nil {
panic(err)
}
return tmcrypto.Address(ethcrypto.PubkeyToAddress(*pubk).Bytes())
}
// Bytes returns the raw bytes of the ECDSA public key.
func (pubKey PubKey) Bytes() []byte {
return pubKey.Key
}
// String implements the fmt.Stringer interface.
func (pubKey PubKey) String() string {
return fmt.Sprintf("EthPubKeySecp256k1{%X}", pubKey.Key)
}
// Type returns eth_secp256k1
func (pubKey PubKey) Type() string {
return KeyType
}
// Equals returns true if the pubkey type is the same and their bytes are deeply equal.
func (pubKey PubKey) Equals(other cryptotypes.PubKey) bool {
return pubKey.Type() == other.Type() && bytes.Equal(pubKey.Bytes(), other.Bytes())
}
// MarshalAmino overrides Amino binary marshalling.
func (pubKey PubKey) MarshalAmino() ([]byte, error) {
return pubKey.Key, nil
}
// UnmarshalAmino overrides Amino binary marshalling.
func (pubKey *PubKey) UnmarshalAmino(bz []byte) error {
if len(bz) != PubKeySize {
return sdkerrors.Wrapf(sdkerrors.ErrInvalidPubKey, "invalid pubkey size, expected %d, got %d", PubKeySize, len(bz))
}
pubKey.Key = bz
return nil
}
// MarshalAminoJSON overrides Amino JSON marshalling.
func (pubKey PubKey) MarshalAminoJSON() ([]byte, error) {
// When we marshal to Amino JSON, we don't marshal the "key" field itself,
// just its contents (i.e. the key bytes).
return pubKey.MarshalAmino()
}
// UnmarshalAminoJSON overrides Amino JSON marshalling.
func (pubKey *PubKey) UnmarshalAminoJSON(bz []byte) error {
return pubKey.UnmarshalAmino(bz)
}
// VerifySignature verifies that the ECDSA public key created a given signature over
// the provided message. It will calculate the Keccak256 hash of the message
// prior to verification.
//
// CONTRACT: The signature should be in [R || S] format.
func (pubKey PubKey) VerifySignature(msg []byte, sig []byte) bool {
if len(sig) == ethcrypto.SignatureLength {
// remove recovery ID (V) if contained in the signature
sig = sig[:len(sig)-1]
}
// the signature needs to be in [R || S] format when provided to VerifySignature
return ethcrypto.VerifySignature(pubKey.Key, ethcrypto.Keccak256Hash(msg).Bytes(), sig)
}