rclone/fs/config/obscure/obscure.go
albertony bcdfad3c83 build: update logging statements to make json log work - fixes #6038
This changes log statements from log to fs package, which is required for --use-json-log
to properly make log output in JSON format. The recently added custom linting rule,
handled by ruleguard via gocritic via golangci-lint, warns about these and suggests
the alternative. Fixing was therefore basically running "golangci-lint run --fix",
although some manual fixup of mainly imports are necessary following that.
2024-09-06 17:04:18 +01:00

100 lines
2.5 KiB
Go

// Package obscure contains the Obscure and Reveal commands
package obscure
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"errors"
"fmt"
"io"
"math"
"github.com/rclone/rclone/fs"
)
// 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)
if math.MaxInt32-aes.BlockSize < len(plaintext) {
return "", fmt.Errorf("value too large")
}
ciphertext := make([]byte, aes.BlockSize+len(plaintext))
iv := ciphertext[:aes.BlockSize]
if _, err := io.ReadFull(cryptRand, iv); err != nil {
return "", fmt.Errorf("failed to read iv: %w", err)
}
if err := crypt(ciphertext[aes.BlockSize:], plaintext, iv); err != nil {
return "", fmt.Errorf("encrypt failed: %w", err)
}
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 {
fs.Fatalf(nil, "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 "", fmt.Errorf("base64 decode failed when revealing password - is it obscured?: %w", err)
}
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 "", fmt.Errorf("decrypt failed when revealing password - is it obscured?: %w", err)
}
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 {
fs.Fatalf(nil, "Reveal failed: %v", err)
}
return out
}