eh_downloader_flutter/lib/api/client.dart

import 'dart:convert';
import 'package:cryptography/cryptography.dart';
import 'package:dio/dio.dart';
import 'package:retrofit/retrofit.dart';
import 'api_result.dart';
import 'status.dart';
import 'token.dart';
import 'user.dart';

part 'client.g.dart';

final _pbkdf2a = Pbkdf2(
  macAlgorithm: Hmac.sha512(),
  iterations: 210000,
  bits: 512,
);

final _pbkdf2b = Pbkdf2(
  macAlgorithm: Hmac.sha512(),
  iterations: 1000,
  bits: 512,
);

const _utf8Encoder = Utf8Encoder();
final _salt = _utf8Encoder.convert("eh-downloader-salt");

@RestApi()
abstract class _EHApi {
  factory _EHApi(Dio dio, {required String baseUrl}) = __EHApi;

  @PUT('/user')
  Future<ApiResult<int>> createUser(
      @Query("name") String name, @Query("password") String password,
      {@Query("is_admin") bool? isAdmin,
      @Query("permissions") int? permissions});
  @GET('/user')
  Future<ApiResult<BUser>> getUser(
      {@Query("id") int? id, @Query("username") String? username});

  @GET('/status')
  Future<ApiResult<ServerStatus>> getStatus();

  @PUT('/token')
  Future<ApiResult<Token>> _createToken(
      {@Query("username") required String username,
      @Query("password") required String password,
      @Query("t") required int t,
      @Query("set_cookie") bool? setCookie,
      @Query("http_only") bool? httpOnly,
      @Query("secure") bool? secure});
  @DELETE('/token')
  Future<ApiResult<bool>> deleteToken({@Query("token") String? token});
  @GET('/token')
  Future<ApiResult<TokenWithUserInfo>> getToken({@Query("token") String? token});

  @GET('/file/{id}')
  Future<HttpResponse> getFile(@Path("id") int id);
  @GET('/file/random')
  Future<HttpResponse> getRandomFile({@Query("is_nsfw") bool? isNsfw, @Query("is_ad") bool? isAd, @Query("thumb") bool? thumb});
}

class EHApi extends __EHApi {
  EHApi(Dio dio, {required String baseUrl}): super(dio, baseUrl: baseUrl);
  Future<ApiResult<Token>> createToken(
      {required String username,
      required String password,
      bool? setCookie,
      bool? httpOnly,
      bool? secure}) async {
    int t = DateTime.now().millisecondsSinceEpoch;
    final p =
        await _pbkdf2a.deriveKeyFromPassword(password: password, nonce: _salt);
    final p2 = await _pbkdf2b.deriveKey(
        secretKey: p, nonce: _utf8Encoder.convert(t.toString()));
    final p3 = base64Encode(await p2.extractBytes());
    return await _createToken(
        username: username,
        password: p3,
        t: t,
        setCookie: setCookie,
        httpOnly: httpOnly,
        secure: secure);
  }
}