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 func newChatGPTFake(t *testing.T) *ChatGPTFake {
  39         t.Helper()
  40
  41         f := &ChatGPTFake{}
  42         mux := http.NewServeMux()
  43         mux.HandleFunc("POST /api/accounts/deviceauth/usercode", f.userCode)
  44         mux.HandleFunc("POST /api/accounts/deviceauth/token", f.deviceToken)
  45         mux.HandleFunc("POST /oauth/token", f.oauthToken)
  46
  47         f.Server = httptest.NewServer(mux)
  48         t.Cleanup(f.Close)
  49
  50         return f
  51 }
  52
  53 func newTestChatGPTAuth(t *testing.T, server *ChatGPTFake) *ChatGPTAuth {
  54         t.Helper()
  55
  56         return newChatGPTAuth(filepath.Join(t.TempDir(), chatgptTokenFileName), server.URL)
  57 }
  58
  59 func (f *ChatGPTFake) userCode(w http.ResponseWriter, r *http.Request) {
  60         var body map[string]string
  61
  62         err := json.NewDecoder(r.Body).Decode(&body)
  63         if err != nil || body["client_id"] != chatgptClientID {
  64                 http.Error(w, "bad client", http.StatusBadRequest)
  65
  66                 return
  67         }
  68
  69         chatgptWriteJSON(w, map[string]any{
  70                 "device_auth_id": "device-1",
  71                 "user_code":      "CODE-1234",
  72                 "interval":       "0",
  73         })
  74 }
  75
  76 func (f *ChatGPTFake) deviceToken(w http.ResponseWriter, r *http.Request) {
  77         f.mutex.Lock()
  78         defer f.mutex.Unlock()
  79
  80         var body map[string]string
  81
  82         err := json.NewDecoder(r.Body).Decode(&body)
  83         if err != nil || body["device_auth_id"] != "device-1" || body["user_code"] != "CODE-1234" {
  84                 http.Error(w, "bad device", http.StatusBadRequest)
  85
  86                 return
  87         }
  88
  89         f.polls++
  90         if f.deny {
  91                 http.Error(w, "denied", http.StatusBadRequest)
  92
  93                 return
  94         }
  95
  96         if f.polls <= f.pending {
  97                 http.Error(w, "pending", http.StatusForbidden)
  98
  99                 return
 100         }
 101
 102         chatgptWriteJSON(w, map[string]any{
 103                 "authorization_code": "auth-code",
 104                 "code_challenge":     "challenge",
 105                 "code_verifier":      "verifier",
 106         })
 107 }
 108
 109 func (f *ChatGPTFake) oauthToken(w http.ResponseWriter, r *http.Request) {
 110         f.mutex.Lock()
 111         defer f.mutex.Unlock()
 112
 113         if r.Header.Get("Content-Type") == "application/x-www-form-urlencoded" {
 114                 err := r.ParseForm()
 115                 if err != nil {
 116                         http.Error(w, err.Error(), http.StatusBadRequest)
 117
 118                         return
 119                 }
 120
 121                 f.exchange = r.PostForm
 122                 chatgptWriteJSON(w, map[string]any{
 123                         "access_token":  f.newToken(time.Hour),
 124                         "refresh_token": "refresh-1",
 125                         "id_token":      f.newToken(time.Hour),
 126                 })
 127
 128                 return
 129         }
 130
 131         var body map[string]string
 132
 133         err := json.NewDecoder(r.Body).Decode(&body)
 134         if err != nil || body["grant_type"] != "refresh_token" || body["client_id"] != chatgptClientID {
 135                 http.Error(w, "bad refresh", http.StatusBadRequest)
 136
 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
 145                 return
 146         }
 147
 148         answer := map[string]any{
 149                 "access_token": f.newToken(time.Hour),
 150                 "id_token":     f.newToken(time.Hour),
 151         }
 152
 153         if f.newRefresh != "" {
 154                 answer["refresh_token"] = f.newRefresh
 155         }
 156
 157         chatgptWriteJSON(w, answer)
 158 }
 159
 160 // newToken returns a new fake JWT with the expiry and the account claim, and
 161 // keeps it in access. The caller holds the mutex.
 162 func (f *ChatGPTFake) newToken(ttl time.Duration) string {
 163         claims, err := json.Marshal(map[string]any{
 164                 "exp": time.Now().Add(ttl).Unix(),
 165                 chatgptAuthClaim: map[string]any{
 166                         "chatgpt_account_id": chatgptTestAccount,
 167                 },
 168                 "serial": len(f.access),
 169         })
 170         if err != nil {
 171                 panic(err)
 172         }
 173
 174         encode := base64.RawURLEncoding.EncodeToString
 175         token := encode([]byte(`{"alg":"none"}`)) + "." + encode(claims) + "." + encode([]byte("fake"))
 176         f.access = append(f.access, token)
 177
 178         return token
 179 }
 180
 181 // token returns a new access token that expires after ttl, for a token file
 182 // that a test writes.
 183 func (f *ChatGPTFake) token(ttl time.Duration) string {
 184         f.mutex.Lock()
 185         defer f.mutex.Unlock()
 186
 187         return f.newToken(ttl)
 188 }
 189
 190 func chatgptWriteJSON(w http.ResponseWriter, value any) {
 191         w.Header().Set("Content-Type", "application/json")
 192
 193         err := json.NewEncoder(w).Encode(value)
 194         if err != nil {
 195                 panic(fmt.Sprint("encode answer: ", err))
 196         }
 197 }
 198
 199 func chatgptWriteTestTokens(t *testing.T, auth *ChatGPTAuth, access, refresh string) {
 200         t.Helper()
 201
 202         err := auth.write(ChatGPTTokenFile{
 203                 AccessToken:  access,
 204                 RefreshToken: refresh,
 205                 IDToken:      access,
 206                 AccountID:    chatgptTestAccount,
 207         })
 208         require.NoError(t, err)
 209 }