1 files changed, 52 insertions, 0 deletions
diff --git a/danmaku/dmpkg/auth.go b/danmaku/dmpkg/auth.go
new file mode 100644
index 0000000..5a205ad
--- /dev/null
+++ b/danmaku/dmpkg/auth.go
@@ -0,0 +1,52 @@
+/*
+This file implements the auth exchange.
+When Bilibili live client established the WebSocket connection successfully,
+it sends this message at first. The server then responses a OpConnectOk exchange with body `{"code":0}` which indicates success.
+*/
+package dmpkg
+
+import (
+	"bilibili-livestream-archiver/common"
+	"encoding/json"
+	"fmt"
+)
+
+type authInfo struct {
+	UID      uint64 `json:"uid"`
+	RoomId   uint64 `json:"roomid"`
+	ProtoVer int    `json:"protover"`
+	Platform string `json:"platform"`
+	Type     int    `json:"type"`
+	Key      string `json:"key"`
+}
+
+// NewAuth creates a new authentication exchange.
+func NewAuth(protocol ProtocolVer, roomId common.RoomId, authKey string) (exc DanmakuExchange) {
+	exc, _ = NewPlainExchange(OpConnect, authInfo{
+		UID:      kUidGuest,
+		RoomId:   uint64(roomId),
+		ProtoVer: int(protocol),
+		Platform: kPlatformWeb,
+		Type:     kAuthTypeDefault,
+		Key:      authKey,
+	})
+	return
+}
+
+func IsAuthOk(serverResponse DanmakuExchange) (bool, error) {
+	if op := serverResponse.Operation; op != OpConnectOk {
+		return false, fmt.Errorf("server operation is not OpConnectOk: %w", op)
+	}
+	var body struct {
+		Code int `json:"code"`
+	}
+	body.Code = 1
+	err := json.Unmarshal(serverResponse.Body, &body)
+	if err != nil {
+		return false, fmt.Errorf("JSON decode error: %w", err)
+	}
+	if c := body.Code; c != 0 {
+		return false, fmt.Errorf("server response code is non-zero: %w", c)
+	}
+	return true, nil
+}