101 lines
2.5 KiB
Go
101 lines
2.5 KiB
Go
// Copyright 2019 The Gitea Authors. All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package context
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import (
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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"crypto/sha256"
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"encoding/base64"
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"errors"
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"io"
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)
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// NewSecret creates a new secret
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func NewSecret() (string, error) {
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return NewSecretWithLength(32)
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}
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// NewSecretWithLength creates a new secret for a given length
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func NewSecretWithLength(length int64) (string, error) {
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return randomString(length)
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}
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func randomBytes(len int64) ([]byte, error) {
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b := make([]byte, len)
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if _, err := rand.Read(b); err != nil {
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return nil, err
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}
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return b, nil
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}
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func randomString(len int64) (string, error) {
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b, err := randomBytes(len)
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return base64.URLEncoding.EncodeToString(b), err
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}
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// AesEncrypt encrypts text and given key with AES.
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func AesEncrypt(key, text []byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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b := base64.StdEncoding.EncodeToString(text)
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ciphertext := make([]byte, aes.BlockSize+len(b))
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iv := ciphertext[:aes.BlockSize]
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if _, err := io.ReadFull(rand.Reader, iv); err != nil {
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return nil, err
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}
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cfb := cipher.NewCFBEncrypter(block, iv)
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cfb.XORKeyStream(ciphertext[aes.BlockSize:], []byte(b))
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return ciphertext, nil
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}
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// AesDecrypt decrypts text and given key with AES.
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func AesDecrypt(key, text []byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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if len(text) < aes.BlockSize {
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return nil, errors.New("ciphertext too short")
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}
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iv := text[:aes.BlockSize]
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text = text[aes.BlockSize:]
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cfb := cipher.NewCFBDecrypter(block, iv)
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cfb.XORKeyStream(text, text)
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data, err := base64.StdEncoding.DecodeString(string(text))
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if err != nil {
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return nil, err
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}
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return data, nil
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}
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// EncryptSecret encrypts a string with given key into a hex string
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func EncryptSecret(key string, str string) (string, error) {
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keyHash := sha256.Sum256([]byte(key))
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plaintext := []byte(str)
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ciphertext, err := AesEncrypt(keyHash[:], plaintext)
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if err != nil {
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return "", err
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}
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return base64.StdEncoding.EncodeToString(ciphertext), nil
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}
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// DecryptSecret decrypts a previously encrypted hex string
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func DecryptSecret(key string, cipherhex string) (string, error) {
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keyHash := sha256.Sum256([]byte(key))
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ciphertext, err := base64.StdEncoding.DecodeString(cipherhex)
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if err != nil {
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return "", err
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}
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plaintext, err := AesDecrypt(keyHash[:], ciphertext)
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if err != nil {
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return "", err
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}
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return string(plaintext), nil
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}
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