grafana/pkg/util/encryption.go

67 lines
1.5 KiB
Go

package util
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"io"
"github.com/grafana/grafana/pkg/log"
)
func Decrypt(payload []byte, secret string) []byte {
key := encryptionKeyToBytes(secret)
block, err := aes.NewCipher(key)
if err != nil {
log.Fatal(4, err.Error())
}
// The IV needs to be unique, but not secure. Therefore it's common to
// include it at the beginning of the ciphertext.
if len(payload) < aes.BlockSize {
log.Fatal(4, "payload too short")
}
iv := payload[:aes.BlockSize]
payload = payload[aes.BlockSize:]
stream := cipher.NewCFBDecrypter(block, iv)
// XORKeyStream can work in-place if the two arguments are the same.
stream.XORKeyStream(payload, payload)
return payload
}
func Encrypt(payload []byte, secret string) []byte {
key := encryptionKeyToBytes(secret)
block, err := aes.NewCipher(key)
if err != nil {
log.Fatal(4, err.Error())
}
// The IV needs to be unique, but not secure. Therefore it's common to
// include it at the beginning of the ciphertext.
ciphertext := make([]byte, aes.BlockSize+len(payload))
iv := ciphertext[:aes.BlockSize]
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
log.Fatal(4, err.Error())
}
stream := cipher.NewCFBEncrypter(block, iv)
stream.XORKeyStream(ciphertext[aes.BlockSize:], payload)
return ciphertext
}
// Key needs to be 32bytes
func encryptionKeyToBytes(secret string) []byte {
key := make([]byte, 32, 32)
keyBytes := []byte(secret)
secretLength := len(keyBytes)
for i := 0; i < 32; i++ {
key[i] = keyBytes[i%secretLength]
}
return key
}