76 lines
1.9 KiB
Go
76 lines
1.9 KiB
Go
package main
|
||
|
||
// synccrypto.go 提供 API Key 加密同步所需的密码学原语：
|
||
// 密钥由登录密码 + 每用户随机盐经 PBKDF2-SHA256 派生（服务器只存盐，无法还原密钥），
|
||
// 密文使用 AES-256-GCM，格式为 base64(nonce || ciphertext)。
|
||
|
||
import (
|
||
"crypto/aes"
|
||
"crypto/cipher"
|
||
"crypto/rand"
|
||
"crypto/sha256"
|
||
"encoding/base64"
|
||
"encoding/hex"
|
||
"errors"
|
||
|
||
"golang.org/x/crypto/pbkdf2"
|
||
)
|
||
|
||
const encKeyIterations = 120_000
|
||
|
||
// deriveEncKey 由登录密码和随机盐派生 32 字节 AES 密钥。
|
||
func deriveEncKey(password string, salt []byte) []byte {
|
||
return pbkdf2.Key([]byte(password), salt, encKeyIterations, 32, sha256.New)
|
||
}
|
||
|
||
// newSaltHex 生成 16 字节随机盐（hex 编码）。
|
||
func newSaltHex() (string, error) {
|
||
salt := make([]byte, 16)
|
||
if _, e := rand.Read(salt); e != nil {
|
||
return "", e
|
||
}
|
||
return hex.EncodeToString(salt), nil
|
||
}
|
||
|
||
// encryptWithKey 用 AES-256-GCM 加密，返回 base64(nonce || ciphertext)。
|
||
func encryptWithKey(key []byte, plaintext string) (string, error) {
|
||
block, e := aes.NewCipher(key)
|
||
if e != nil {
|
||
return "", e
|
||
}
|
||
gcm, e := cipher.NewGCM(block)
|
||
if e != nil {
|
||
return "", e
|
||
}
|
||
nonce := make([]byte, gcm.NonceSize())
|
||
if _, e := rand.Read(nonce); e != nil {
|
||
return "", e
|
||
}
|
||
sealed := gcm.Seal(nonce, nonce, []byte(plaintext), nil)
|
||
return base64.StdEncoding.EncodeToString(sealed), nil
|
||
}
|
||
|
||
// decryptWithKey 解密 encryptWithKey 的输出；密钥不符或数据被篡改时报错。
|
||
func decryptWithKey(key []byte, blob string) (string, error) {
|
||
raw, e := base64.StdEncoding.DecodeString(blob)
|
||
if e != nil {
|
||
return "", e
|
||
}
|
||
block, e := aes.NewCipher(key)
|
||
if e != nil {
|
||
return "", e
|
||
}
|
||
gcm, e := cipher.NewGCM(block)
|
||
if e != nil {
|
||
return "", e
|
||
}
|
||
if len(raw) < gcm.NonceSize() {
|
||
return "", errors.New("ciphertext too short")
|
||
}
|
||
plain, e := gcm.Open(nil, raw[:gcm.NonceSize()], raw[gcm.NonceSize():], nil)
|
||
if e != nil {
|
||
return "", e
|
||
}
|
||
return string(plain), nil
|
||
}
|