Files
higress/plugins/wasm-go/extensions/ai-security-guard/main.go
2024-06-17 10:41:46 +08:00

273 lines
8.6 KiB
Go

package main
import (
"crypto/hmac"
"crypto/rand"
"crypto/sha1"
"encoding/base64"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"net/http"
"net/url"
"sort"
"strings"
"time"
"github.com/alibaba/higress/plugins/wasm-go/pkg/wrapper"
"github.com/higress-group/proxy-wasm-go-sdk/proxywasm"
"github.com/higress-group/proxy-wasm-go-sdk/proxywasm/types"
"github.com/tidwall/gjson"
)
func main() {
wrapper.SetCtx(
"ai-security-guard",
wrapper.ParseConfigBy(parseConfig),
wrapper.ProcessRequestHeadersBy(onHttpRequestHeaders),
wrapper.ProcessRequestBodyBy(onHttpRequestBody),
wrapper.ProcessResponseHeadersBy(onHttpResponseHeaders),
wrapper.ProcessResponseBodyBy(onHttpResponseBody),
)
}
type AISecurityConfig struct {
client wrapper.HttpClient
ak string
sk string
}
type StandardResponse struct {
Code int `json:"Code"`
Phase string `json:"BlockPhase"`
Message string `json:"Message"`
}
func urlEncoding(rawStr string) string {
encodedStr := url.PathEscape(rawStr)
encodedStr = strings.ReplaceAll(encodedStr, "+", "%20")
encodedStr = strings.ReplaceAll(encodedStr, ":", "%3A")
encodedStr = strings.ReplaceAll(encodedStr, "=", "%3D")
encodedStr = strings.ReplaceAll(encodedStr, "&", "%26")
return encodedStr
}
func hmacSha1(message, secret string) string {
key := []byte(secret)
h := hmac.New(sha1.New, key)
h.Write([]byte(message))
hash := h.Sum(nil)
return base64.StdEncoding.EncodeToString(hash)
}
func getSign(params map[string]string, secret string) string {
paramArray := []string{}
for k, v := range params {
paramArray = append(paramArray, urlEncoding(k)+"="+urlEncoding(v))
}
sort.Slice(paramArray, func(i, j int) bool {
return paramArray[i] <= paramArray[j]
})
canonicalStr := strings.Join(paramArray, "&")
signStr := "POST&%2F&" + urlEncoding(canonicalStr)
fmt.Println(signStr)
return hmacSha1(signStr, secret)
}
func generateHexID(length int) (string, error) {
bytes := make([]byte, length/2)
if _, err := rand.Read(bytes); err != nil {
return "", err
}
return hex.EncodeToString(bytes), nil
}
func parseConfig(json gjson.Result, config *AISecurityConfig, log wrapper.Log) error {
serviceName := json.Get("serviceName").String()
servicePort := json.Get("servicePort").Int()
domain := json.Get("domain").String()
config.ak = json.Get("ak").String()
config.sk = json.Get("sk").String()
if serviceName == "" || servicePort == 0 || domain == "" {
return errors.New("invalid service config")
}
config.client = wrapper.NewClusterClient(wrapper.DnsCluster{
ServiceName: serviceName,
Port: servicePort,
Domain: domain,
})
return nil
}
func onHttpRequestHeaders(ctx wrapper.HttpContext, config AISecurityConfig, log wrapper.Log) types.Action {
return types.ActionContinue
}
func onHttpRequestBody(ctx wrapper.HttpContext, config AISecurityConfig, body []byte, log wrapper.Log) types.Action {
messages := gjson.GetBytes(body, "messages").Array()
if len(messages) > 0 {
role := messages[len(messages)-1].Get("role").String()
content := messages[len(messages)-1].Get("content").String()
if role != "user" {
return types.ActionContinue
}
timestamp := time.Now().UTC().Format("2006-01-02T15:04:05Z")
randomID, _ := generateHexID(16)
params := map[string]string{
"Format": "JSON",
"Version": "2022-03-02",
"SignatureMethod": "Hmac-SHA1",
"SignatureNonce": randomID,
"SignatureVersion": "1.0",
"Action": "TextModerationPlus",
"AccessKeyId": config.ak,
"Timestamp": timestamp,
"Service": "llm_query_moderation",
"ServiceParameters": `{"content": "` + content + `"}`,
}
signature := getSign(params, config.sk+"&")
reqParams := url.Values{}
for k, v := range params {
reqParams.Add(k, v)
}
reqParams.Add("Signature", signature)
config.client.Post(fmt.Sprintf("/?%s", reqParams.Encode()), nil, nil,
func(statusCode int, responseHeaders http.Header, responseBody []byte) {
respData := gjson.GetBytes(responseBody, "Data")
if respData.Exists() {
respAdvice := respData.Get("Advice")
respResult := respData.Get("Result")
if respAdvice.Exists() {
sr := StandardResponse{
Code: 403,
Phase: "Request",
Message: respAdvice.Array()[0].Get("Answer").String(),
}
jsonData, _ := json.MarshalIndent(sr, "", " ")
proxywasm.SetProperty([]string{"risklabel"}, []byte(respResult.Array()[0].Get("Label").String()))
proxywasm.SendHttpResponse(403, [][2]string{{"content-type", "application/json"}}, jsonData, -1)
} else if respResult.Array()[0].Get("Label").String() != "nonLabel" {
sr := StandardResponse{
Code: 403,
Phase: "Request",
Message: "risk detected",
}
jsonData, _ := json.MarshalIndent(sr, "", " ")
proxywasm.SetProperty([]string{"risklabel"}, []byte(respResult.Array()[0].Get("Label").String()))
proxywasm.SendHttpResponse(403, [][2]string{{"content-type", "application/json"}}, jsonData, -1)
} else {
proxywasm.ResumeHttpRequest()
}
} else {
proxywasm.ResumeHttpRequest()
}
},
)
return types.ActionPause
} else {
return types.ActionContinue
}
}
func convertHeaders(hs [][2]string) map[string][]string {
ret := make(map[string][]string)
for _, h := range hs {
k, v := strings.ToLower(h[0]), h[1]
ret[k] = append(ret[k], v)
}
return ret
}
// headers: map[string][]string -> [][2]string
func reconvertHeaders(hs map[string][]string) [][2]string {
var ret [][2]string
for k, vs := range hs {
for _, v := range vs {
ret = append(ret, [2]string{k, v})
}
}
sort.SliceStable(ret, func(i, j int) bool {
return ret[i][0] < ret[j][0]
})
return ret
}
func onHttpResponseHeaders(ctx wrapper.HttpContext, config AISecurityConfig, log wrapper.Log) types.Action {
headers, err := proxywasm.GetHttpResponseHeaders()
if err != nil {
log.Warnf("failed to get response headers: %v", err)
return types.ActionContinue
}
hdsMap := convertHeaders(headers)
ctx.SetContext("headers", hdsMap)
return types.HeaderStopIteration
}
func onHttpResponseBody(ctx wrapper.HttpContext, config AISecurityConfig, body []byte, log wrapper.Log) types.Action {
messages := gjson.GetBytes(body, "choices").Array()
if len(messages) > 0 {
content := messages[0].Get("message").Get("content").String()
timestamp := time.Now().UTC().Format("2006-01-02T15:04:05Z")
randomID, _ := generateHexID(16)
params := map[string]string{
"Format": "JSON",
"Version": "2022-03-02",
"SignatureMethod": "Hmac-SHA1",
"SignatureNonce": randomID,
"SignatureVersion": "1.0",
"Action": "TextModerationPlus",
"AccessKeyId": config.ak,
"Timestamp": timestamp,
"Service": "llm_response_moderation",
"ServiceParameters": `{"content": "` + content + `"}`,
}
signature := getSign(params, config.sk+"&")
reqParams := url.Values{}
for k, v := range params {
reqParams.Add(k, v)
}
reqParams.Add("Signature", signature)
config.client.Post(fmt.Sprintf("/?%s", reqParams.Encode()), nil, nil,
func(statusCode int, responseHeaders http.Header, responseBody []byte) {
defer proxywasm.ResumeHttpResponse()
respData := gjson.GetBytes(responseBody, "Data")
if respData.Exists() {
respAdvice := respData.Get("Advice")
respResult := respData.Get("Result")
if respAdvice.Exists() {
sr := StandardResponse{
Code: 403,
Phase: "Response",
Message: respAdvice.Array()[0].Get("Answer").String(),
}
jsonData, _ := json.MarshalIndent(sr, "", " ")
hdsMap := ctx.GetContext("headers").(map[string][]string)
delete(hdsMap, "content-length")
hdsMap[":status"] = []string{"403"}
proxywasm.ReplaceHttpResponseHeaders(reconvertHeaders(hdsMap))
proxywasm.ReplaceHttpResponseBody(jsonData)
proxywasm.SetProperty([]string{"risklabel"}, []byte(respResult.Array()[0].Get("Label").String()))
} else if respResult.Array()[0].Get("Label").String() != "nonLabel" {
sr := StandardResponse{
Code: 403,
Phase: "Response",
Message: "risk detected",
}
jsonData, _ := json.MarshalIndent(sr, "", " ")
hdsMap := ctx.GetContext("headers").(map[string][]string)
delete(hdsMap, "content-length")
hdsMap[":status"] = []string{"403"}
proxywasm.ReplaceHttpResponseHeaders(reconvertHeaders(hdsMap))
proxywasm.ReplaceHttpResponseBody(jsonData)
proxywasm.SetProperty([]string{"risklabel"}, []byte(respResult.Array()[0].Get("Label").String()))
}
}
},
)
return types.ActionPause
} else {
return types.ActionContinue
}
}