mirror of
https://github.com/rclone/rclone.git
synced 2024-11-23 00:43:49 +01:00
95 lines
2.4 KiB
Go
95 lines
2.4 KiB
Go
// Package obscure contains the Obscure and Reveal commands
|
|
package obscure
|
|
|
|
import (
|
|
"crypto/aes"
|
|
"crypto/cipher"
|
|
"crypto/rand"
|
|
"encoding/base64"
|
|
"io"
|
|
"log"
|
|
|
|
"github.com/pkg/errors"
|
|
)
|
|
|
|
// crypt internals
|
|
var (
|
|
cryptKey = []byte{
|
|
0x9c, 0x93, 0x5b, 0x48, 0x73, 0x0a, 0x55, 0x4d,
|
|
0x6b, 0xfd, 0x7c, 0x63, 0xc8, 0x86, 0xa9, 0x2b,
|
|
0xd3, 0x90, 0x19, 0x8e, 0xb8, 0x12, 0x8a, 0xfb,
|
|
0xf4, 0xde, 0x16, 0x2b, 0x8b, 0x95, 0xf6, 0x38,
|
|
}
|
|
cryptBlock cipher.Block
|
|
cryptRand = rand.Reader
|
|
)
|
|
|
|
// crypt transforms in to out using iv under AES-CTR.
|
|
//
|
|
// in and out may be the same buffer.
|
|
//
|
|
// Note encryption and decryption are the same operation
|
|
func crypt(out, in, iv []byte) error {
|
|
if cryptBlock == nil {
|
|
var err error
|
|
cryptBlock, err = aes.NewCipher(cryptKey)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
stream := cipher.NewCTR(cryptBlock, iv)
|
|
stream.XORKeyStream(out, in)
|
|
return nil
|
|
}
|
|
|
|
// Obscure a value
|
|
//
|
|
// This is done by encrypting with AES-CTR
|
|
func Obscure(x string) (string, error) {
|
|
plaintext := []byte(x)
|
|
ciphertext := make([]byte, aes.BlockSize+len(plaintext))
|
|
iv := ciphertext[:aes.BlockSize]
|
|
if _, err := io.ReadFull(cryptRand, iv); err != nil {
|
|
return "", errors.Wrap(err, "failed to read iv")
|
|
}
|
|
if err := crypt(ciphertext[aes.BlockSize:], plaintext, iv); err != nil {
|
|
return "", errors.Wrap(err, "encrypt failed")
|
|
}
|
|
return base64.RawURLEncoding.EncodeToString(ciphertext), nil
|
|
}
|
|
|
|
// MustObscure obscures a value, exiting with a fatal error if it failed
|
|
func MustObscure(x string) string {
|
|
out, err := Obscure(x)
|
|
if err != nil {
|
|
log.Fatalf("Obscure failed: %v", err)
|
|
}
|
|
return out
|
|
}
|
|
|
|
// Reveal an obscured value
|
|
func Reveal(x string) (string, error) {
|
|
ciphertext, err := base64.RawURLEncoding.DecodeString(x)
|
|
if err != nil {
|
|
return "", errors.Wrap(err, "base64 decode failed when revealing password - is it obscured?")
|
|
}
|
|
if len(ciphertext) < aes.BlockSize {
|
|
return "", errors.New("input too short when revealing password - is it obscured?")
|
|
}
|
|
buf := ciphertext[aes.BlockSize:]
|
|
iv := ciphertext[:aes.BlockSize]
|
|
if err := crypt(buf, buf, iv); err != nil {
|
|
return "", errors.Wrap(err, "decrypt failed when revealing password - is it obscured?")
|
|
}
|
|
return string(buf), nil
|
|
}
|
|
|
|
// MustReveal reveals an obscured value, exiting with a fatal error if it failed
|
|
func MustReveal(x string) string {
|
|
out, err := Reveal(x)
|
|
if err != nil {
|
|
log.Fatalf("Reveal failed: %v", err)
|
|
}
|
|
return out
|
|
}
|