git.giacomolli.uk - onechat/blob - chatgpt_fake_helper_test.go

   1 package main
   2
   3 import (
   4         "encoding/base64"
   5         "encoding/json"
   6         "fmt"
   7         "net/http"
   8         "net/http/httptest"
   9         "net/url"
  10         "path/filepath"
  11         "sync"
  12         "testing"
  13         "time"
  14
  15         "github.com/stretchr/testify/require"
  16 )
  17
  18 // chatgptTestAccount is the fake ChatGPT account ID in the fake tokens.
  19 const chatgptTestAccount = "account-test"
  20
  21 // ChatGPTFake is an httptest login service. The device token endpoint answers
  22 // 403 pending times before it grants the code. Each token answer has a new
  23 // access token, kept in access.
  24 type ChatGPTFake struct {
  25         *httptest.Server
  26         mutex       sync.Mutex
  27         pending     int
  28         deny        bool
  29         polls       int
  30         exchange    url.Values
  31         refreshes   int
  32         refreshed   string
  33         newRefresh  string
  34         failRefresh bool
  35         access      []string
  36 }
  37
  38 // token returns a new access token that expires after ttl, for a token file
  39 // that a test writes.
  40 func (f *ChatGPTFake) token(ttl time.Duration) string {
  41         f.mutex.Lock()
  42         defer f.mutex.Unlock()
  43
  44         return f.newToken(ttl)
  45 }
  46
  47 // newToken returns a new fake JWT with the expiry and the account claim, and
  48 // keeps it in access. The caller holds the mutex.
  49 func (f *ChatGPTFake) newToken(ttl time.Duration) string {
  50         claims, err := json.Marshal(map[string]any{
  51                 "exp": time.Now().Add(ttl).Unix(),
  52                 chatgptAuthClaim: map[string]any{
  53                         "chatgpt_account_id": chatgptTestAccount,
  54                 },
  55                 "serial": len(f.access),
  56         })
  57         if err != nil {
  58                 panic(err)
  59         }
  60
  61         encode := base64.RawURLEncoding.EncodeToString
  62         token := encode([]byte(`{"alg":"none"}`)) + "." + encode(claims) + "." + encode([]byte("fake"))
  63         f.access = append(f.access, token)
  64
  65         return token
  66 }
  67
  68 func (f *ChatGPTFake) userCode(w http.ResponseWriter, r *http.Request) {
  69         var body map[string]string
  70         err := json.NewDecoder(r.Body).Decode(&body)
  71         if err != nil || body["client_id"] != chatgptClientID {
  72                 http.Error(w, "bad client", http.StatusBadRequest)
  73                 return
  74         }
  75
  76         chatgptWriteJSON(w, map[string]any{
  77                 "device_auth_id": "device-1",
  78                 "user_code":      "CODE-1234",
  79                 "interval":       "0",
  80         })
  81 }
  82
  83 func (f *ChatGPTFake) deviceToken(w http.ResponseWriter, r *http.Request) {
  84         f.mutex.Lock()
  85         defer f.mutex.Unlock()
  86
  87         var body map[string]string
  88         err := json.NewDecoder(r.Body).Decode(&body)
  89         if err != nil || body["device_auth_id"] != "device-1" || body["user_code"] != "CODE-1234" {
  90                 http.Error(w, "bad device", http.StatusBadRequest)
  91                 return
  92         }
  93
  94         f.polls++
  95         if f.deny {
  96                 http.Error(w, "denied", http.StatusBadRequest)
  97                 return
  98         }
  99
 100         if f.polls <= f.pending {
 101                 http.Error(w, "pending", http.StatusForbidden)
 102                 return
 103         }
 104
 105         chatgptWriteJSON(w, map[string]any{
 106                 "authorization_code": "auth-code",
 107                 "code_challenge":     "challenge",
 108                 "code_verifier":      "verifier",
 109         })
 110 }
 111
 112 func (f *ChatGPTFake) oauthToken(w http.ResponseWriter, r *http.Request) {
 113         f.mutex.Lock()
 114         defer f.mutex.Unlock()
 115
 116         if r.Header.Get("Content-Type") == "application/x-www-form-urlencoded" {
 117                 err := r.ParseForm()
 118                 if err != nil {
 119                         http.Error(w, err.Error(), http.StatusBadRequest)
 120                         return
 121                 }
 122
 123                 f.exchange = r.PostForm
 124                 chatgptWriteJSON(w, map[string]any{
 125                         "access_token":  f.newToken(time.Hour),
 126                         "refresh_token": "refresh-1",
 127                         "id_token":      f.newToken(time.Hour),
 128                 })
 129
 130                 return
 131         }
 132
 133         var body map[string]string
 134         err := json.NewDecoder(r.Body).Decode(&body)
 135         if err != nil || body["grant_type"] != "refresh_token" || body["client_id"] != chatgptClientID {
 136                 http.Error(w, "bad refresh", http.StatusBadRequest)
 137                 return
 138         }
 139
 140         f.refreshes++
 141         f.refreshed = body["refresh_token"]
 142         if f.failRefresh {
 143                 http.Error(w, `{"error": "invalid_grant", "token": "`+body["refresh_token"]+`"}`, http.StatusUnauthorized)
 144                 return
 145         }
 146
 147         answer := map[string]any{
 148                 "access_token": f.newToken(time.Hour),
 149                 "id_token":     f.newToken(time.Hour),
 150         }
 151
 152         if f.newRefresh != "" {
 153                 answer["refresh_token"] = f.newRefresh
 154         }
 155
 156         chatgptWriteJSON(w, answer)
 157 }
 158
 159 func newChatGPTFake(t *testing.T) *ChatGPTFake {
 160         t.Helper()
 161
 162         f := &ChatGPTFake{}
 163         mux := http.NewServeMux()
 164         mux.HandleFunc("POST /api/accounts/deviceauth/usercode", f.userCode)
 165         mux.HandleFunc("POST /api/accounts/deviceauth/token", f.deviceToken)
 166         mux.HandleFunc("POST /oauth/token", f.oauthToken)
 167         f.Server = httptest.NewServer(mux)
 168         t.Cleanup(f.Close)
 169
 170         return f
 171 }
 172
 173 func newTestChatGPTAuth(t *testing.T, server *ChatGPTFake) *ChatGPTAuth {
 174         t.Helper()
 175
 176         return newChatGPTAuth(filepath.Join(t.TempDir(), chatgptTokenFileName), server.URL)
 177 }
 178
 179 func chatgptWriteTestTokens(t *testing.T, auth *ChatGPTAuth, access, refresh string) {
 180         t.Helper()
 181
 182         err := auth.write(ChatGPTTokenFile{
 183                 AccessToken:  access,
 184                 RefreshToken: refresh,
 185                 IDToken:      access,
 186                 AccountID:    chatgptTestAccount,
 187         })
 188         require.NoError(t, err)
 189 }
 190
 191 func chatgptWriteJSON(w http.ResponseWriter, value any) {
 192         w.Header().Set("Content-Type", "application/json")
 193         err := json.NewEncoder(w).Encode(value)
 194         if err != nil {
 195                 panic(fmt.Sprint("encode answer: ", err))
 196         }
 197 }