status-go/api/utils.go

60 lines
1.3 KiB
Go

package api
import (
"bytes"
"encoding/hex"
"strconv"
"strings"
"github.com/ethereum/go-ethereum/crypto"
)
// RunAsync runs the specified function asynchronously.
func RunAsync(f func() error) <-chan error {
resp := make(chan error, 1)
go func() {
err := f()
resp <- err
close(resp)
}()
return resp
}
// HashMessage calculates the hash of a message to be safely signed by the keycard
// The hash is calulcated as
// keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
// This gives context to the signed message and prevents signing of transactions.
func HashMessage(message string) ([]byte, error) {
buf := bytes.NewBufferString("\x19Ethereum Signed Message:\n")
if value, ok := decodeHexStrict(message); ok {
if _, err := buf.WriteString(strconv.Itoa(len(value))); err != nil {
return nil, err
}
if _, err := buf.Write(value); err != nil {
return nil, err
}
} else {
if _, err := buf.WriteString(strconv.Itoa(len(message))); err != nil {
return nil, err
}
if _, err := buf.WriteString(message); err != nil {
return nil, err
}
}
return crypto.Keccak256(buf.Bytes()), nil
}
func decodeHexStrict(s string) ([]byte, bool) {
if !strings.HasPrefix(s, "0x") {
return nil, false
}
value, err := hex.DecodeString(s[2:])
if err != nil {
return nil, false
}
return value, true
}