go-pulse/signer/core/signed_data.go
2021-12-05 14:31:41 +01:00

333 lines
12 KiB
Go

// Copyright 2019 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package core
import (
"context"
"errors"
"fmt"
"mime"
"github.com/ethereum/go-ethereum/accounts"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/consensus/clique"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/rlp"
"github.com/ethereum/go-ethereum/signer/core/apitypes"
)
// sign receives a request and produces a signature
//
// Note, the produced signature conforms to the secp256k1 curve R, S and V values,
// where the V value will be 27 or 28 for legacy reasons, if legacyV==true.
func (api *SignerAPI) sign(req *SignDataRequest, legacyV bool) (hexutil.Bytes, error) {
// We make the request prior to looking up if we actually have the account, to prevent
// account-enumeration via the API
res, err := api.UI.ApproveSignData(req)
if err != nil {
return nil, err
}
if !res.Approved {
return nil, ErrRequestDenied
}
// Look up the wallet containing the requested signer
account := accounts.Account{Address: req.Address.Address()}
wallet, err := api.am.Find(account)
if err != nil {
return nil, err
}
pw, err := api.lookupOrQueryPassword(account.Address,
"Password for signing",
fmt.Sprintf("Please enter password for signing data with account %s", account.Address.Hex()))
if err != nil {
return nil, err
}
// Sign the data with the wallet
signature, err := wallet.SignDataWithPassphrase(account, pw, req.ContentType, req.Rawdata)
if err != nil {
return nil, err
}
if legacyV {
signature[64] += 27 // Transform V from 0/1 to 27/28 according to the yellow paper
}
return signature, nil
}
// SignData signs the hash of the provided data, but does so differently
// depending on the content-type specified.
//
// Different types of validation occur.
func (api *SignerAPI) SignData(ctx context.Context, contentType string, addr common.MixedcaseAddress, data interface{}) (hexutil.Bytes, error) {
var req, transformV, err = api.determineSignatureFormat(ctx, contentType, addr, data)
if err != nil {
return nil, err
}
signature, err := api.sign(req, transformV)
if err != nil {
api.UI.ShowError(err.Error())
return nil, err
}
return signature, nil
}
// determineSignatureFormat determines which signature method should be used based upon the mime type
// In the cases where it matters ensure that the charset is handled. The charset
// resides in the 'params' returned as the second returnvalue from mime.ParseMediaType
// charset, ok := params["charset"]
// As it is now, we accept any charset and just treat it as 'raw'.
// This method returns the mimetype for signing along with the request
func (api *SignerAPI) determineSignatureFormat(ctx context.Context, contentType string, addr common.MixedcaseAddress, data interface{}) (*SignDataRequest, bool, error) {
var (
req *SignDataRequest
useEthereumV = true // Default to use V = 27 or 28, the legacy Ethereum format
)
mediaType, _, err := mime.ParseMediaType(contentType)
if err != nil {
return nil, useEthereumV, err
}
switch mediaType {
case apitypes.IntendedValidator.Mime:
// Data with an intended validator
validatorData, err := UnmarshalValidatorData(data)
if err != nil {
return nil, useEthereumV, err
}
sighash, msg := SignTextValidator(validatorData)
messages := []*apitypes.NameValueType{
{
Name: "This is a request to sign data intended for a particular validator (see EIP 191 version 0)",
Typ: "description",
Value: "",
},
{
Name: "Intended validator address",
Typ: "address",
Value: validatorData.Address.String(),
},
{
Name: "Application-specific data",
Typ: "hexdata",
Value: validatorData.Message,
},
{
Name: "Full message for signing",
Typ: "hexdata",
Value: fmt.Sprintf("0x%x", msg),
},
}
req = &SignDataRequest{ContentType: mediaType, Rawdata: []byte(msg), Messages: messages, Hash: sighash}
case apitypes.ApplicationClique.Mime:
// Clique is the Ethereum PoA standard
stringData, ok := data.(string)
if !ok {
return nil, useEthereumV, fmt.Errorf("input for %v must be an hex-encoded string", apitypes.ApplicationClique.Mime)
}
cliqueData, err := hexutil.Decode(stringData)
if err != nil {
return nil, useEthereumV, err
}
header := &types.Header{}
if err := rlp.DecodeBytes(cliqueData, header); err != nil {
return nil, useEthereumV, err
}
// The incoming clique header is already truncated, sent to us with a extradata already shortened
if len(header.Extra) < 65 {
// Need to add it back, to get a suitable length for hashing
newExtra := make([]byte, len(header.Extra)+65)
copy(newExtra, header.Extra)
header.Extra = newExtra
}
// Get back the rlp data, encoded by us
sighash, cliqueRlp, err := cliqueHeaderHashAndRlp(header)
if err != nil {
return nil, useEthereumV, err
}
messages := []*apitypes.NameValueType{
{
Name: "Clique header",
Typ: "clique",
Value: fmt.Sprintf("clique header %d [0x%x]", header.Number, header.Hash()),
},
}
// Clique uses V on the form 0 or 1
useEthereumV = false
req = &SignDataRequest{ContentType: mediaType, Rawdata: cliqueRlp, Messages: messages, Hash: sighash}
default: // also case TextPlain.Mime:
// Calculates an Ethereum ECDSA signature for:
// hash = keccak256("\x19${byteVersion}Ethereum Signed Message:\n${message length}${message}")
// We expect it to be a string
if stringData, ok := data.(string); !ok {
return nil, useEthereumV, fmt.Errorf("input for text/plain must be an hex-encoded string")
} else {
if textData, err := hexutil.Decode(stringData); err != nil {
return nil, useEthereumV, err
} else {
sighash, msg := accounts.TextAndHash(textData)
messages := []*apitypes.NameValueType{
{
Name: "message",
Typ: accounts.MimetypeTextPlain,
Value: msg,
},
}
req = &SignDataRequest{ContentType: mediaType, Rawdata: []byte(msg), Messages: messages, Hash: sighash}
}
}
}
req.Address = addr
req.Meta = MetadataFromContext(ctx)
return req, useEthereumV, nil
}
// SignTextWithValidator signs the given message which can be further recovered
// with the given validator.
// hash = keccak256("\x19\x00"${address}${data}).
func SignTextValidator(validatorData apitypes.ValidatorData) (hexutil.Bytes, string) {
msg := fmt.Sprintf("\x19\x00%s%s", string(validatorData.Address.Bytes()), string(validatorData.Message))
return crypto.Keccak256([]byte(msg)), msg
}
// cliqueHeaderHashAndRlp returns the hash which is used as input for the proof-of-authority
// signing. It is the hash of the entire header apart from the 65 byte signature
// contained at the end of the extra data.
//
// The method requires the extra data to be at least 65 bytes -- the original implementation
// in clique.go panics if this is the case, thus it's been reimplemented here to avoid the panic
// and simply return an error instead
func cliqueHeaderHashAndRlp(header *types.Header) (hash, rlp []byte, err error) {
if len(header.Extra) < 65 {
err = fmt.Errorf("clique header extradata too short, %d < 65", len(header.Extra))
return
}
rlp = clique.CliqueRLP(header)
hash = clique.SealHash(header).Bytes()
return hash, rlp, err
}
// SignTypedData signs EIP-712 conformant typed data
// hash = keccak256("\x19${byteVersion}${domainSeparator}${hashStruct(message)}")
// It returns
// - the signature,
// - and/or any error
func (api *SignerAPI) SignTypedData(ctx context.Context, addr common.MixedcaseAddress, typedData apitypes.TypedData) (hexutil.Bytes, error) {
signature, _, err := api.signTypedData(ctx, addr, typedData, nil)
return signature, err
}
// signTypedData is identical to the capitalized version, except that it also returns the hash (preimage)
// - the signature preimage (hash)
func (api *SignerAPI) signTypedData(ctx context.Context, addr common.MixedcaseAddress,
typedData apitypes.TypedData, validationMessages *apitypes.ValidationMessages) (hexutil.Bytes, hexutil.Bytes, error) {
domainSeparator, err := typedData.HashStruct("EIP712Domain", typedData.Domain.Map())
if err != nil {
return nil, nil, err
}
typedDataHash, err := typedData.HashStruct(typedData.PrimaryType, typedData.Message)
if err != nil {
return nil, nil, err
}
rawData := []byte(fmt.Sprintf("\x19\x01%s%s", string(domainSeparator), string(typedDataHash)))
sighash := crypto.Keccak256(rawData)
messages, err := typedData.Format()
if err != nil {
return nil, nil, err
}
req := &SignDataRequest{
ContentType: apitypes.DataTyped.Mime,
Rawdata: rawData,
Messages: messages,
Hash: sighash,
Address: addr}
if validationMessages != nil {
req.Callinfo = validationMessages.Messages
}
signature, err := api.sign(req, true)
if err != nil {
api.UI.ShowError(err.Error())
return nil, nil, err
}
return signature, sighash, nil
}
// EcRecover recovers the address associated with the given sig.
// Only compatible with `text/plain`
func (api *SignerAPI) EcRecover(ctx context.Context, data hexutil.Bytes, sig hexutil.Bytes) (common.Address, error) {
// Returns the address for the Account that was used to create the signature.
//
// Note, this function is compatible with eth_sign and personal_sign. As such it recovers
// the address of:
// hash = keccak256("\x19${byteVersion}Ethereum Signed Message:\n${message length}${message}")
// addr = ecrecover(hash, signature)
//
// Note, the signature must conform to the secp256k1 curve R, S and V values, where
// the V value must be be 27 or 28 for legacy reasons.
//
// https://github.com/ethereum/go-ethereum/wiki/Management-APIs#personal_ecRecover
if len(sig) != 65 {
return common.Address{}, fmt.Errorf("signature must be 65 bytes long")
}
if sig[64] != 27 && sig[64] != 28 {
return common.Address{}, fmt.Errorf("invalid Ethereum signature (V is not 27 or 28)")
}
sig[64] -= 27 // Transform yellow paper V from 27/28 to 0/1
hash := accounts.TextHash(data)
rpk, err := crypto.SigToPub(hash, sig)
if err != nil {
return common.Address{}, err
}
return crypto.PubkeyToAddress(*rpk), nil
}
// UnmarshalValidatorData converts the bytes input to typed data
func UnmarshalValidatorData(data interface{}) (apitypes.ValidatorData, error) {
raw, ok := data.(map[string]interface{})
if !ok {
return apitypes.ValidatorData{}, errors.New("validator input is not a map[string]interface{}")
}
addr, ok := raw["address"].(string)
if !ok {
return apitypes.ValidatorData{}, errors.New("validator address is not sent as a string")
}
addrBytes, err := hexutil.Decode(addr)
if err != nil {
return apitypes.ValidatorData{}, err
}
if !ok || len(addrBytes) == 0 {
return apitypes.ValidatorData{}, errors.New("validator address is undefined")
}
message, ok := raw["message"].(string)
if !ok {
return apitypes.ValidatorData{}, errors.New("message is not sent as a string")
}
messageBytes, err := hexutil.Decode(message)
if err != nil {
return apitypes.ValidatorData{}, err
}
if !ok || len(messageBytes) == 0 {
return apitypes.ValidatorData{}, errors.New("message is undefined")
}
return apitypes.ValidatorData{
Address: common.BytesToAddress(addrBytes),
Message: messageBytes,
}, nil
}