github.com/phillinzzz/newBsc@v1.1.6/cmd/ethkey/utils.go (about)

     1  // Copyright 2017 The go-ethereum Authors
     2  // This file is part of go-ethereum.
     3  //
     4  // go-ethereum is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // go-ethereum is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU General Public License
    15  // along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package main
    18  
    19  import (
    20  	"encoding/json"
    21  	"fmt"
    22  	"io/ioutil"
    23  	"strings"
    24  
    25  	"github.com/phillinzzz/newBsc/cmd/utils"
    26  	"github.com/phillinzzz/newBsc/crypto"
    27  	"gopkg.in/urfave/cli.v1"
    28  )
    29  
    30  // getPassphrase obtains a passphrase given by the user.  It first checks the
    31  // --passfile command line flag and ultimately prompts the user for a
    32  // passphrase.
    33  func getPassphrase(ctx *cli.Context, confirmation bool) string {
    34  	// Look for the --passwordfile flag.
    35  	passphraseFile := ctx.String(passphraseFlag.Name)
    36  	if passphraseFile != "" {
    37  		content, err := ioutil.ReadFile(passphraseFile)
    38  		if err != nil {
    39  			utils.Fatalf("Failed to read password file '%s': %v",
    40  				passphraseFile, err)
    41  		}
    42  		return strings.TrimRight(string(content), "\r\n")
    43  	}
    44  
    45  	// Otherwise prompt the user for the passphrase.
    46  	return utils.GetPassPhrase("", confirmation)
    47  }
    48  
    49  // signHash is a helper function that calculates a hash for the given message
    50  // that can be safely used to calculate a signature from.
    51  //
    52  // The hash is calulcated as
    53  //   keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
    54  //
    55  // This gives context to the signed message and prevents signing of transactions.
    56  func signHash(data []byte) []byte {
    57  	msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), data)
    58  	return crypto.Keccak256([]byte(msg))
    59  }
    60  
    61  // mustPrintJSON prints the JSON encoding of the given object and
    62  // exits the program with an error message when the marshaling fails.
    63  func mustPrintJSON(jsonObject interface{}) {
    64  	str, err := json.MarshalIndent(jsonObject, "", "  ")
    65  	if err != nil {
    66  		utils.Fatalf("Failed to marshal JSON object: %v", err)
    67  	}
    68  	fmt.Println(string(str))
    69  }