0904

internal/security/censor/aliyun.go

@@ -0,0 +1,194 @@
+// Copyright 2022 E99p1ant. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package censor
+
+import (
+	"context"
+	"encoding/json"
+	"sync"
+	"time"
+
+	"github.com/aliyun/alibaba-cloud-sdk-go/services/green"
+	"github.com/pkg/errors"
+)
+
+type AliyunTextCensor struct {
+	accessKey, accessKeySecret string
+}
+
+func NewAliyunTextCensor(accessKey, accessKeySecret string) *AliyunTextCensor {
+	return &AliyunTextCensor{
+		accessKey:       accessKey,
+		accessKeySecret: accessKeySecret,
+	}
+}
+
+// 包级复用的 green.Client：审核请求高频且密钥在启动后不变，
+// 用 sync.Once 懒加载一次并设置超时，避免每次审核都重建连接与对象。
+var (
+	aliyunGreenOnce   sync.Once
+	aliyunGreenClient *green.Client
+	aliyunGreenErr    error
+)
+
+func (c *AliyunTextCensor) getClient() (*green.Client, error) {
+	aliyunGreenOnce.Do(func() {
+		aliyunGreenClient, aliyunGreenErr = green.NewClientWithAccessKey("cn-shanghai", c.accessKey, c.accessKeySecret)
+		if aliyunGreenErr == nil {
+			aliyunGreenClient.SetConnectTimeout(5 * time.Second)
+			aliyunGreenClient.SetReadTimeout(10 * time.Second)
+		}
+	})
+	return aliyunGreenClient, aliyunGreenErr
+}
+
+type AliyunTextCensorResponse struct {
+	Code int `json:"code"`
+	Data []struct {
+		Code            int    `json:"code"`
+		Content         string `json:"content"`
+		FilteredContent string `json:"filteredContent"`
+		Msg             string `json:"msg"`
+		Results         []struct {
+			Details []struct {
+				Contexts []struct {
+					Context   string `json:"context"`
+					Positions []struct {
+						EndPos   int `json:"endPos"`
+						StartPos int `json:"startPos"`
+					} `json:"positions"`
+				} `json:"contexts"`
+				Label string `json:"label"`
+			} `json:"details"`
+			Label      string  `json:"label"`
+			Rate       float64 `json:"rate"`
+			Scene      string  `json:"scene"`
+			Suggestion string  `json:"suggestion"`
+		} `json:"results"`
+		TaskId string `json:"taskId"`
+	} `json:"data"`
+	Msg       string `json:"msg"`
+	RequestId string `json:"requestId"`
+}
+
+func (r *AliyunTextCensorResponse) IsPass() bool {
+	if len(r.Data) == 0 || len(r.Data[0].Results) == 0 {
+		return false
+	}
+
+	// ⚠️ Right now, we allow `review` and `pass` to pass the censor.
+	// 任一 scene 判定为 block 即不通过（此前只检查首个 result，存在漏审）。
+	for _, result := range r.Data[0].Results {
+		if result.Suggestion == "block" {
+			return false
+		}
+	}
+	return true
+}
+
+// Censor censors text with Aliyun API.
+// https://developer.qiniu.com/censor/7260/api-text-censor
+func (c *AliyunTextCensor) Censor(_ context.Context, text string) (*TextCensorResponse, error) {
+	client, err := c.getClient()
+	if err != nil {
+		return nil, errors.Wrap(err, "new client with access key")
+	}
+
+	content, err := json.Marshal(
+		map[string]interface{}{
+			"scenes": []string{"antispam"},
+			"tasks": []map[string]interface{}{
+				{"content": text},
+			},
+		},
+	)
+	if err != nil {
+		return nil, errors.Wrap(err, "marshal content")
+	}
+
+	req := green.CreateTextScanRequest()
+	req.SetContent(content)
+	resp, err := client.TextScan(req)
+	if err != nil {
+		return nil, errors.Wrap(err, "text scan")
+	}
+
+	if !resp.IsSuccess() {
+		return nil, errors.New("response is not success")
+	}
+
+	return AliyunTextCensorParser(resp.GetHttpContentBytes())
+}
+
+func (*AliyunTextCensor) String() string {
+	return "aliyun"
+}
+
+func AliyunTextCensorParser(raw []byte) (*TextCensorResponse, error) {
+	var responseJSON AliyunTextCensorResponse
+	if err := json.Unmarshal(raw, &responseJSON); err != nil {
+		return nil, errors.Wrap(err, "unmarshal response")
+	}
+
+	if len(responseJSON.Data) == 0 {
+		return nil, errors.New("response data is empty")
+	}
+
+	var hint string
+	var label string
+	var confidence float64
+	for _, result := range responseJSON.Data[0].Results {
+		if result.Label == "normal" {
+			continue
+		}
+
+		// Get the first context as the hint, forbidden type, confidence.
+		for _, detail := range result.Details {
+			for _, context := range detail.Contexts {
+				hint = context.Context
+			}
+		}
+
+		label = result.Label
+		confidence = result.Rate
+		break
+	}
+
+	return &TextCensorResponse{
+		SourceName:    "aliyun",
+		Pass:          responseJSON.IsPass(),
+		ForbiddenType: formatAliyunForbiddenType(label),
+		Hint:          hint,
+		Confidence:    confidence,
+		RawResponse:   raw,
+	}, nil
+}
+
+func formatAliyunForbiddenType(typ string) ForbiddenType {
+	switch typ {
+	case "spam":
+		return ForbiddenTypeSpam
+	case "ad":
+		return ForbiddenTypeAd
+	case "politics":
+		return ForbiddenTypePolitics
+	case "terrorism":
+		return ForbiddenTypeTerrorism
+	case "abuse":
+		return ForbiddenTypeAbuse
+	case "porn":
+		return ForbiddenTypePorn
+	case "flood":
+		return ForbiddenTypeFlood
+	case "contraband":
+		return ForbiddenTypeContraband
+	case "meaningless":
+		return ForbiddenTypeMeaningless
+	case "harmful":
+		return ForbiddenTypeHarmful
+	default:
+		return ""
+	}
+}