fix special charactor handle in ai-security-guard plugin (#1394)

plugins/wasm-go/extensions/ai-security-guard/main.go

@@ -81,7 +81,7 @@ func (config *AISecurityConfig) incrementCounter(metricName string, inc uint64)
 
 func urlEncoding(rawStr string) string {
 	encodedStr := url.PathEscape(rawStr)
-	encodedStr = strings.ReplaceAll(encodedStr, "+", "%20")
+	encodedStr = strings.ReplaceAll(encodedStr, "+", "%2B")
 	encodedStr = strings.ReplaceAll(encodedStr, ":", "%3A")
 	encodedStr = strings.ReplaceAll(encodedStr, "=", "%3D")
 	encodedStr = strings.ReplaceAll(encodedStr, "&", "%26")
@@ -106,7 +106,7 @@ func getSign(params map[string]string, secret string) string {
 	})
 	canonicalStr := strings.Join(paramArray, "&")
 	signStr := "POST&%2F&" + urlEncoding(canonicalStr)
-	// proxywasm.LogInfo(signStr)
+	proxywasm.LogDebugf("String to sign is: %s", signStr)
 	return hmacSha1(signStr, secret)
 }
 
@@ -196,10 +196,11 @@ func onHttpRequestHeaders(ctx wrapper.HttpContext, config AISecurityConfig, log
 
 func onHttpRequestBody(ctx wrapper.HttpContext, config AISecurityConfig, body []byte, log wrapper.Log) types.Action {
 	log.Debugf("checking request body...")
-	content := gjson.GetBytes(body, config.requestContentJsonPath).String()
+	content := gjson.GetBytes(body, config.requestContentJsonPath).Raw
 	model := gjson.GetBytes(body, "model").Raw
 	ctx.SetContext("requestModel", model)
-	if content != "" {
+	log.Debugf("Raw response content is: %s", content)
+	if len(content) > 0 {
 		timestamp := time.Now().UTC().Format("2006-01-02T15:04:05Z")
 		randomID, _ := generateHexID(16)
 		params := map[string]string{
@@ -212,7 +213,7 @@ func onHttpRequestBody(ctx wrapper.HttpContext, config AISecurityConfig, body []
 			"AccessKeyId":       config.ak,
 			"Timestamp":         timestamp,
 			"Service":           config.requestCheckService,
-			"ServiceParameters": `{"content": "` + content + `"}`,
+			"ServiceParameters": fmt.Sprintf(`{"content": %s}`, content),
 		}
 		signature := getSign(params, config.sk+"&")
 		reqParams := url.Values{}
@@ -339,7 +340,7 @@ func onHttpResponseBody(ctx wrapper.HttpContext, config AISecurityConfig, body [
 	if isStreamingResponse {
 		content = extractMessageFromStreamingBody(body, config.responseStreamContentJsonPath)
 	} else {
-		content = gjson.GetBytes(body, config.responseContentJsonPath).String()
+		content = gjson.GetBytes(body, config.responseContentJsonPath).Raw
 	}
 	log.Debugf("Raw response content is: %s", content)
 	if len(content) > 0 {
@@ -355,7 +356,7 @@ func onHttpResponseBody(ctx wrapper.HttpContext, config AISecurityConfig, body [
 			"AccessKeyId":       config.ak,
 			"Timestamp":         timestamp,
 			"Service":           config.responseCheckService,
-			"ServiceParameters": `{"content": "` + content + `"}`,
+			"ServiceParameters": fmt.Sprintf(`{"content": %s}`, content),
 		}
 		signature := getSign(params, config.sk+"&")
 		reqParams := url.Values{}
@@ -400,10 +401,10 @@ func onHttpResponseBody(ctx wrapper.HttpContext, config AISecurityConfig, body [
 							jsonData = []byte(denyMessage)
 						} else if strings.Contains(strings.Join(hdsMap["content-type"], ";"), "event-stream") {
 							randomID := generateRandomID()
-							jsonData = []byte(fmt.Sprintf(OpenAIStreamResponseFormat, randomID, model, respAdvice.Array()[0].Get("Answer").String(), randomID, model))
+							jsonData = []byte(fmt.Sprintf(OpenAIStreamResponseFormat, randomID, model, denyMessage, randomID, model))
 						} else {
 							randomID := generateRandomID()
-							jsonData = []byte(fmt.Sprintf(OpenAIResponseFormat, randomID, model, respAdvice.Array()[0].Get("Answer").String()))
+							jsonData = []byte(fmt.Sprintf(OpenAIResponseFormat, randomID, model, denyMessage))
 						}
 						delete(hdsMap, "content-length")
 						hdsMap[":status"] = []string{fmt.Sprint(config.denyCode)}
@@ -432,10 +433,10 @@ func extractMessageFromStreamingBody(data []byte, jsonPath string) string {
 	strChunks := []string{}
 	for _, chunk := range chunks {
 		// Example: "choices":[{"index":0,"delta":{"role":"assistant","content":"%s"},"logprobs":null,"finish_reason":null}]
-		jsonObj := gjson.GetBytes(chunk, jsonPath)
-		if jsonObj.Exists() {
-			strChunks = append(strChunks, jsonObj.String())
+		jsonRaw := gjson.GetBytes(chunk, jsonPath).Raw
+		if len(jsonRaw) > 2 {
+			strChunks = append(strChunks, jsonRaw[1:len(jsonRaw)-1])
 		}
 	}
-	return strings.Join(strChunks, "")
+	return fmt.Sprintf(`"%s"`, strings.Join(strChunks, ""))
 }