dc4bc/airgapped/encryption.go

65 lines
1.2 KiB
Go

package airgapped
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"fmt"
"golang.org/x/crypto/scrypt"
"io"
)
func encrypt(key, salt, data []byte) ([]byte, error) {
derivedKey, err := scrypt.Key(key, salt, 32768, 8, 1, 32)
if err != nil {
return nil, err
}
c, err := aes.NewCipher(derivedKey)
if err != nil {
return nil, err
}
gcm, err := cipher.NewGCM(c)
if err != nil {
return nil, err
}
nonce := make([]byte, gcm.NonceSize())
if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
return nil, err
}
return gcm.Seal(nonce, nonce, data, nil), nil
}
func decrypt(key, salt, data []byte) ([]byte, error) {
derivedKey, err := scrypt.Key(key, salt, 32768, 8, 1, 32)
if err != nil {
return nil, err
}
c, err := aes.NewCipher(derivedKey)
if err != nil {
return nil, err
}
gcm, err := cipher.NewGCM(c)
if err != nil {
return nil, err
}
nonceSize := gcm.NonceSize()
if len(data) < nonceSize {
return nil, fmt.Errorf("invalid data length")
}
nonce, ciphertext := data[:nonceSize], data[nonceSize:]
decryptedData, err := gcm.Open(nil, nonce, ciphertext, nil)
if err != nil {
return nil, err
}
return decryptedData, nil
}