pollo/lib/crypto.go

85 lines
1.8 KiB
Go

package lib
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"crypto/sha256"
"encoding/base64"
"errors"
"fmt"
"os"
)
// Returns the first 32 bytes of the SHA-256 hash of the ENCRYPTION_KEY environment variable
func GetEncryptionKey() []byte {
key := []byte(os.Getenv("ENCRYPTION_KEY"))
hash := sha256.Sum256(key)
return hash[:32] // Use the first 32 bytes for AES-256
}
// Encrypt data using AES
func Encrypt(data []byte) (string, error) {
encryptionKey := GetEncryptionKey()
fmt.Printf("Encryption Key Length: %d\n", len(encryptionKey))
block, err := aes.NewCipher(encryptionKey)
if err != nil {
return "", err
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return "", err
}
nonce := make([]byte, gcm.NonceSize())
_, err = rand.Read(nonce)
if err != nil {
return "", err
}
cipherText := gcm.Seal(nonce, nonce, data, nil)
return base64.StdEncoding.EncodeToString(cipherText), nil
}
// decrypt decrypts the data using AES-GCM.
func Decrypt(encryptedString string) (string, error) {
encryptionKey := GetEncryptionKey()
data, err := base64.StdEncoding.DecodeString(encryptedString)
if err != nil {
return "", err
}
block, err := aes.NewCipher(encryptionKey)
if err != nil {
return "", err
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return "", err
}
nonceSize := gcm.NonceSize()
if len(data) < nonceSize {
return "", errors.New("ciphertext too short")
}
nonce, ciphertext := data[:nonceSize], data[nonceSize:]
plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
if err != nil {
return "", err
}
return string(plaintext), nil
}
// GenerateRandomBytes returns securely generated random bytes.
func GenerateRandomBytes(n int) ([]byte, error) {
b := make([]byte, n)
_, err := rand.Read(b)
if err != nil {
return nil, err
}
return b, nil
}