Files
sub2api/backend/internal/payment/crypto.go
erio 61a008f7e4 chore(payment): mark legacy AES ciphertext fallback as deprecated
明文 JSON 已经是新写入的默认格式;保留 AES 密文读取仅为兼容迁移期间的旧
记录,一旦所有部署通过管理后台重存过一次即可删除。标记为 deprecated 并加
TODO,几个版本后统一清理掉:payment.Encrypt / payment.Decrypt、两处
decryptConfig 的 AES 分支、PaymentConfigService.encryptionKey 和
DefaultLoadBalancer.encryptionKey 字段。
2026-04-17 23:24:27 +08:00

112 lines
3.4 KiB
Go

package payment
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"fmt"
"io"
"strings"
)
// AES256KeySize is the required key length (in bytes) for AES-256-GCM.
const AES256KeySize = 32
// Encrypt encrypts plaintext using AES-256-GCM with the given 32-byte key.
// The output format is "iv:authTag:ciphertext" where each component is base64-encoded,
// matching the Node.js crypto.ts format for cross-compatibility.
//
// Deprecated: payment provider configs are now stored as plaintext JSON.
// This function is kept only for seeding legacy ciphertext in tests and for
// the transitional Decrypt fallback. Scheduled for removal after all live
// deployments complete migration by re-saving their configs.
func Encrypt(plaintext string, key []byte) (string, error) {
if len(key) != AES256KeySize {
return "", fmt.Errorf("encryption key must be %d bytes, got %d", AES256KeySize, len(key))
}
block, err := aes.NewCipher(key)
if err != nil {
return "", fmt.Errorf("create AES cipher: %w", err)
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return "", fmt.Errorf("create GCM: %w", err)
}
nonce := make([]byte, gcm.NonceSize()) // 12 bytes for GCM
if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
return "", fmt.Errorf("generate nonce: %w", err)
}
// Seal appends the ciphertext + auth tag
sealed := gcm.Seal(nil, nonce, []byte(plaintext), nil)
// Split sealed into ciphertext and auth tag (last 16 bytes)
tagSize := gcm.Overhead()
ciphertext := sealed[:len(sealed)-tagSize]
authTag := sealed[len(sealed)-tagSize:]
// Format: iv:authTag:ciphertext (all base64)
return fmt.Sprintf("%s:%s:%s",
base64.StdEncoding.EncodeToString(nonce),
base64.StdEncoding.EncodeToString(authTag),
base64.StdEncoding.EncodeToString(ciphertext),
), nil
}
// Decrypt decrypts a ciphertext string produced by Encrypt.
// The input format is "iv:authTag:ciphertext" where each component is base64-encoded.
//
// Deprecated: payment provider configs are now stored as plaintext JSON.
// This function remains only as a read-path fallback for pre-migration
// ciphertext records. Scheduled for removal once all deployments re-save
// their provider configs through the admin UI.
func Decrypt(ciphertext string, key []byte) (string, error) {
if len(key) != AES256KeySize {
return "", fmt.Errorf("encryption key must be %d bytes, got %d", AES256KeySize, len(key))
}
parts := strings.SplitN(ciphertext, ":", 3)
if len(parts) != 3 {
return "", fmt.Errorf("invalid ciphertext format: expected iv:authTag:ciphertext")
}
nonce, err := base64.StdEncoding.DecodeString(parts[0])
if err != nil {
return "", fmt.Errorf("decode IV: %w", err)
}
authTag, err := base64.StdEncoding.DecodeString(parts[1])
if err != nil {
return "", fmt.Errorf("decode auth tag: %w", err)
}
encrypted, err := base64.StdEncoding.DecodeString(parts[2])
if err != nil {
return "", fmt.Errorf("decode ciphertext: %w", err)
}
block, err := aes.NewCipher(key)
if err != nil {
return "", fmt.Errorf("create AES cipher: %w", err)
}
gcm, err := cipher.NewGCM(block)
if err != nil {
return "", fmt.Errorf("create GCM: %w", err)
}
// Reconstruct the sealed data: ciphertext + authTag
sealed := append(encrypted, authTag...)
plaintext, err := gcm.Open(nil, nonce, sealed, nil)
if err != nil {
return "", fmt.Errorf("decrypt: %w", err)
}
return string(plaintext), nil
}