gitea/modules/secret/secret.go

79 lines
2.3 KiB
Go

// Copyright 2019 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package secret
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"crypto/sha256"
"encoding/base64"
"encoding/hex"
"errors"
"fmt"
"io"
)
// AesEncrypt encrypts text and given key with AES.
func AesEncrypt(key, text []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, fmt.Errorf("AesEncrypt invalid key: %v", err)
}
b := base64.StdEncoding.EncodeToString(text)
ciphertext := make([]byte, aes.BlockSize+len(b))
iv := ciphertext[:aes.BlockSize]
if _, err = io.ReadFull(rand.Reader, iv); err != nil {
return nil, fmt.Errorf("AesEncrypt unable to read IV: %w", err)
}
cfb := cipher.NewCFBEncrypter(block, iv)
cfb.XORKeyStream(ciphertext[aes.BlockSize:], []byte(b))
return ciphertext, nil
}
// AesDecrypt decrypts text and given key with AES.
func AesDecrypt(key, text []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
if len(text) < aes.BlockSize {
return nil, errors.New("AesDecrypt ciphertext too short")
}
iv := text[:aes.BlockSize]
text = text[aes.BlockSize:]
cfb := cipher.NewCFBDecrypter(block, iv)
cfb.XORKeyStream(text, text)
data, err := base64.StdEncoding.DecodeString(string(text))
if err != nil {
return nil, fmt.Errorf("AesDecrypt invalid decrypted base64 string: %w", err)
}
return data, nil
}
// EncryptSecret encrypts a string with given key into a hex string
func EncryptSecret(key, str string) (string, error) {
keyHash := sha256.Sum256([]byte(key))
plaintext := []byte(str)
ciphertext, err := AesEncrypt(keyHash[:], plaintext)
if err != nil {
return "", fmt.Errorf("failed to encrypt by secret: %w", err)
}
return hex.EncodeToString(ciphertext), nil
}
// DecryptSecret decrypts a previously encrypted hex string
func DecryptSecret(key, cipherHex string) (string, error) {
keyHash := sha256.Sum256([]byte(key))
ciphertext, err := hex.DecodeString(cipherHex)
if err != nil {
return "", fmt.Errorf("failed to decrypt by secret, invalid hex string: %w", err)
}
plaintext, err := AesDecrypt(keyHash[:], ciphertext)
if err != nil {
return "", fmt.Errorf("failed to decrypt by secret, the key (maybe SECRET_KEY?) might be incorrect: %w", err)
}
return string(plaintext), nil
}