twofactor/vendor/github.com/sec51/cryptoengine/file_utils.go
2016-11-15 19:43:36 -07:00

120 lines
2.7 KiB
Go

package cryptoengine
import (
"encoding/hex"
"fmt"
"io/ioutil"
"log"
"os"
"path/filepath"
)
const (
testKeyPath = "test_keys"
)
var (
keyPath string
keysFolderPrefixFormat string
testKeysFolderPrefixFormat string
)
// create the keys folder if it does not exist, with the proper permission
func init() {
if os.Getenv("SEC51_KEYPATH") != "" {
keyPath = os.Getenv("SEC51_KEYPATH")
} else {
keyPath = "keys"
}
keysFolderPrefixFormat = filepath.Join(keyPath, "%s")
testKeysFolderPrefixFormat = filepath.Join(testKeyPath, "%s")
if err := createBaseKeyFolder(keyPath); err != nil {
log.Println(err)
}
}
// Check if a file exists
func fileExists(filename string) bool {
_, err := os.Stat(filename)
return err == nil
}
// Check if a key file exists
func keyFileExists(filename string) bool {
_, err := os.Stat(fmt.Sprintf(keysFolderPrefixFormat, filename))
return err == nil
}
// Read the full file into a byte slice
func readFile(filename string) ([]byte, error) {
return ioutil.ReadFile(filename)
}
// Writes a file with read only permissions
// If the file already exists then it returns the specific error: os.ErrExist
// This is thanks to the flag O_CREATE
func writeFile(filename string, data []byte) error {
if fileExists(filename) {
return os.ErrExist
}
file, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE, 0400)
if err != nil {
log.Println(err)
return err
}
_, err = file.Write(data)
return err
}
// Read the key file into a 32 byte array
func readKey(filename, pathFormat string) ([keySize]byte, error) {
var data32 [keySize]byte
// read the data back
data, err := readFile(fmt.Sprintf(pathFormat, filename))
if err != nil {
return data32, err
}
// decode from hex
dst := make([]byte, len(data))
_, err = hex.Decode(dst, data) //.StdEncoding.Decode(dst, data)
if err != nil {
return data32, err
}
// fill in the 32 byte array witht he data and return it
copy(data32[:], dst[:keySize])
return data32, err
}
// Write the key file hex encoded
func writeKey(filename, pathFormat string, data []byte) error {
dst := make([]byte, hex.EncodedLen(len(data))) //StdEncoding.EncodedLen(len(data)))
hex.Encode(dst, data) // StdEncoding.Encode(dst, data)
filePath := fmt.Sprintf(pathFormat, filename)
return writeFile(filePath, dst)
}
// Check if the file or directory exists and then deletes it
func deleteFile(filename string) error {
if fileExists(filename) {
return os.Remove(filename)
}
return nil
}
func createBaseKeyFolder(path string) error {
if fileExists(path) {
return nil
}
return os.MkdirAll(path, 0700)
}
func removeFolder(path string) error {
return os.RemoveAll(path)
}