aboutsummaryrefslogtreecommitdiffstats
path: root/modules/secret/secret.go
blob: e7edc7a95e528e3c5b96942742c73c340f084f7e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package secret

import (
	"crypto/aes"
	"crypto/cipher"
	"crypto/rand"
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	"errors"
	"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, 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, 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("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, 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 "", 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 "", err
	}
	plaintext, err := AesDecrypt(keyHash[:], ciphertext)
	if err != nil {
		return "", err
	}
	return string(plaintext), nil
}