feat: 增加商户消息加密密钥管理

server/internal/library/immessagecrypto/key.go

@@ -0,0 +1,76 @@
+package immessagecrypto
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/binary"
+	"hotgo/internal/consts"
+	"hotgo/internal/dao"
+	"hotgo/utility/encrypt"
+
+	"github.com/gogf/gf/v2/errors/gerror"
+)
+
+func GenerateDEK() ([]byte, error) {
+	key := make([]byte, encrypt.AESGCMKeySize)
+	if _, err := rand.Read(key); err != nil {
+		return nil, gerror.Wrap(err, "生成商户消息密钥失败")
+	}
+	return key, nil
+}
+
+func WrapDEK(ctx context.Context, tenantID int64, version uint, dek []byte) (ciphertext, nonce []byte, err error) {
+	kek, err := loadRootKEK(ctx)
+	if err != nil {
+		return nil, nil, err
+	}
+	return encrypt.AESGCMEncrypt(dek, kek, keyAAD(tenantID, version))
+}
+
+func UnwrapDEK(ctx context.Context, tenantID int64, version uint, ciphertext, nonce []byte) ([]byte, error) {
+	kek, err := loadRootKEK(ctx)
+	if err != nil {
+		return nil, err
+	}
+	dek, err := encrypt.AESGCMDecrypt(ciphertext, nonce, kek, keyAAD(tenantID, version))
+	if err != nil {
+		return nil, gerror.Wrap(err, "解包商户消息密钥失败")
+	}
+	if len(dek) != encrypt.AESGCMKeySize {
+		return nil, gerror.New("商户消息密钥长度不正确")
+	}
+	return dek, nil
+}
+
+func EncodeDEK(dek []byte) string {
+	return base64.StdEncoding.EncodeToString(dek)
+}
+
+func loadRootKEK(ctx context.Context) ([]byte, error) {
+	columns := dao.SysDictData.Columns()
+	value, err := dao.SysDictData.Ctx(ctx).
+		Fields(columns.Value).
+		Where(columns.Type, consts.ImInternalSecretDictType).
+		Where(columns.Label, consts.ImMessageRootKEKLabel).
+		Where(columns.Status, consts.StatusEnabled).
+		Value()
+	if err != nil {
+		return nil, gerror.Wrap(err, "读取消息根密钥失败")
+	}
+	if value.IsEmpty() {
+		return nil, gerror.New("消息根密钥未初始化")
+	}
+	kek, err := base64.StdEncoding.DecodeString(value.String())
+	if err != nil || len(kek) != encrypt.AESGCMKeySize {
+		return nil, gerror.New("消息根密钥格式不正确")
+	}
+	return kek, nil
+}
+
+func keyAAD(tenantID int64, version uint) []byte {
+	aad := make([]byte, 16)
+	binary.BigEndian.PutUint64(aad[:8], uint64(tenantID))
+	binary.BigEndian.PutUint64(aad[8:], uint64(version))
+	return aad
+}