Added config-helper tool to encrypt/decrypt config file.

tools/config/config-helper.go

@@ -0,0 +1,185 @@
+package main
+
+import (
+	"bytes"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+)
+
+const (
+	ENCRYPTION_CONFIRMATION_STRING = "THORS-HAMMER"
+)
+
+func EncryptOrDecrypt(encrypt bool) string {
+	if encrypt {
+		return "encrypted"
+	}
+	return "decrypted"
+}
+
+func main() {
+	var inFile, outFile, key string
+	var encrypt bool
+	var err error
+	flag.StringVar(&inFile, "infile", "config.dat", "The config input file to process.")
+	flag.StringVar(&outFile, "outfile", "config.dat.out", "The config output file.")
+	flag.BoolVar(&encrypt, "encrypt", true, "Wether to encrypt or decrypt.")
+	flag.StringVar(&key, "key", "", "The key to use for AES encryption.")
+	flag.Parse()
+
+	log.Println("GoCryptoTrader: config-helper tool.")
+
+	if key == "" {
+		result, err := PromptForConfigKey()
+		if err != nil {
+			log.Fatal("Unable to obtain encryption/decryption key.")
+		}
+		key = string(result)
+	}
+
+	file, err := ReadFile(inFile)
+	if err != nil {
+		log.Fatalf("Unable to read input file %s. Error: %s.", inFile, err)
+	}
+
+	if ConfirmECS(file) && encrypt {
+		log.Println("File is already encrypted. Decrypting..")
+		encrypt = false
+	}
+
+	if !ConfirmECS(file) && !encrypt {
+		var result interface{}
+		err := ConfirmConfigJSON(file, result)
+		if err != nil {
+			log.Fatal("File isn't in JSON format")
+		}
+		log.Println("File is already decrypted. Encrypting..")
+		encrypt = true
+	}
+
+	var data []byte
+	if encrypt {
+		data, err = EncryptConfigFile(file, []byte(key))
+		if err != nil {
+			log.Fatalf("Unable to encrypt config data. Error: %s.", err)
+		}
+	} else {
+		data, err = DecryptConfigFile(file, []byte(key))
+		if err != nil {
+			log.Fatalf("Unable to decrypt config data. Error: %s.", err)
+		}
+	}
+
+	err = WriteFile(outFile, data)
+	if err != nil {
+		log.Fatalf("Unable to write output file %s. Error: %s", outFile, err)
+	}
+	log.Printf("Successfully %s input file %s and wrote output to %s.\n", EncryptOrDecrypt(encrypt), inFile, outFile)
+}
+
+func ReadFile(path string) ([]byte, error) {
+	file, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	return file, nil
+}
+
+func WriteFile(file string, data []byte) error {
+	err := ioutil.WriteFile(file, data, 0644)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func PromptForConfigKey() ([]byte, error) {
+	var cryptoKey []byte
+
+	for len(cryptoKey) != 32 {
+		log.Println("Enter password (32 characters):")
+
+		_, err := fmt.Scanln(&cryptoKey)
+		if err != nil {
+			return nil, err
+		}
+
+		if len(cryptoKey) > 32 || len(cryptoKey) < 32 {
+			continue
+		}
+	}
+
+	nonce := make([]byte, 12)
+	if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
+		return nil, err
+	}
+
+	return cryptoKey, nil
+}
+
+func EncryptConfigFile(configData, key []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	ciphertext := make([]byte, aes.BlockSize+len(configData))
+	iv := ciphertext[:aes.BlockSize]
+	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
+		return nil, err
+	}
+
+	stream := cipher.NewCFBEncrypter(block, iv)
+	stream.XORKeyStream(ciphertext[aes.BlockSize:], configData)
+
+	appendedFile := []byte(ENCRYPTION_CONFIRMATION_STRING)
+	appendedFile = append(appendedFile, ciphertext...)
+	return appendedFile, nil
+}
+
+func DecryptConfigFile(configData, key []byte) ([]byte, error) {
+	configData = RemoveECS(configData)
+	blockDecrypt, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(configData) < aes.BlockSize {
+		return nil, errors.New("The config file data is too small for the AES required block size.")
+	}
+
+	iv := configData[:aes.BlockSize]
+	configData = configData[aes.BlockSize:]
+
+	stream := cipher.NewCFBDecrypter(blockDecrypt, iv)
+	stream.XORKeyStream(configData, configData)
+	result := configData
+	return result, nil
+}
+
+func ConfirmConfigJSON(file []byte, result interface{}) error {
+	err := json.Unmarshal(file, &result)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func ConfirmECS(file []byte) bool {
+	subslice := []byte(ENCRYPTION_CONFIRMATION_STRING)
+	return bytes.Contains(file, subslice)
+}
+
+func RemoveECS(file []byte) []byte {
+	return bytes.Trim(file, ENCRYPTION_CONFIRMATION_STRING)
+}