一个简单的身份验证机制drogon

Question

加密是暂时的。
我的所有实例 execSqlAsync 函数都有一个非常不可读的错误。

错误是：

In template: invalid operands to binary expression ('std::stringstream' (aka 'basic_stringstream<char>') and 'std::exception') error occurred here in instantiation of function template specialization 'drogon::orm::Field::as<std::exception>' requested here in instantiation of function template specialization 'drogon::orm::internal::CallbackHolder<(lambda at /Users/<br>
41:13)>::makeValue<std::exception>' requested here in instantiation of function template specialization 'drogon::orm::internal::CallbackHolder<(lambda at /Users/
<br>
41:13)>::run<1UL>' requested here in instantiation of function template specialization 'drogon::orm::internal::CallbackHolder<(lambda at <br>
41:13)>::run<true>' requested here in instantiation of member function 'drogon::orm::internal::CallbackHolder<(lambda at /Users/<br>
41:13)>::execCallback' requested here in instantiation of function template specialization 'drogon::orm::internal::CallbackHolder<(lambda at /Users/<br>
41:13)>::CallbackHolder<(lambda at patr... in instantiation of function template specialization 'drogon::orm::internal::SqlBinder::operator>><(lambda at 
<br>
 server/AuthController.cpp:41:13), drogon::orm::internal::FunctionTraits<(lambda at /U... in instantiation of function template specialization 'drogon::orm::DbClient::execSqlAsync<(lambda at <br> server/AuthController.cpp:35:13), (lambda at /<br> server/A... candidate template ignored: deduced conflicting types for parameter '_CharT' ('char' vs. 'std::exception') candidate template ignored: could not match 'uniform_int_distribution<_IT>' against 'std::exception' candidate template ignored: could not match '_CharT[_Np]' against 'std::exception' candidate template ignored: could not match 'unsigned char[_Np]' against 'std::exception' candidate template ignored: could not match 'signed char[_Np]' against 'std::exception' candidate template ignored: could not match 'basic_string<_CharT, _Traits, _Allocator>' against 'std::exception' candidate template ignored: could not match 'bitset<_Size>' against 'std::exception' candidate template ignored: requirement 'integral_constant<bool, false>::value' was not satisfied [with _Stream = std::stringstream &, _Tp = std::exception &] candidate template ignored: could not match '__iom_t7<_MoneyT>' against 'std::exception' candidate template ignored: could not match '__iom_t9<_CharT>' against 'std::exception'

这是代码：

#include "AuthController.h"
#include <drogon/drogon.h>
#include <drogon/orm/DbClient.h>
#include <algorithm>

using namespace drogon;
using namespace drogon::orm;

// Simple Caesar Cipher function
std::string caesarCipher(const std::string& text, int shift) {
    std::string result = text;
    std::transform(result.begin(), result.end(), result.begin(),
                   [shift](char c) -> char {
                       if (c >= 'a' && c <= 'z')
                           return 'a' + (c - 'a' + shift) % 26;
                       else if (c >= 'A' && c <= 'Z')
                           return 'A' + (c - 'A' + shift) % 26;
                       else
                           return c;
                   });
    return result;
}

void AuthController::signup(const HttpRequestPtr &req, std::function<void(const HttpResponsePtr &)> &&callback) {
    auto json = req->getJsonObject();
    std::string username = json->get("username", "").asString();
    std::string password = json->get("password", "").asString();

    // Encrypt the password using Caesar cipher
    std::string encryptedPassword = caesarCipher(password, 3);

    auto client = drogon::app().getDbClient().get();
    client->execSqlAsync(
            "INSERT INTO users (username, password_hash) VALUES ($1, $2)",
            [callback](const Result &result) {
                auto response = HttpResponse::newHttpResponse();
                response->setStatusCode(HttpStatusCode::k200OK);
                response->setBody("Signup successful");
                callback(response);
            },
            [callback](const std::exception &e) {  // Correct exception handling
                auto response = HttpResponse::newHttpResponse();
                response->setStatusCode(HttpStatusCode::k500InternalServerError);
                response->setBody(e.what());
                callback(response);
            },
            username, encryptedPassword);
}

void AuthController::login(const HttpRequestPtr &req, std::function<void(const HttpResponsePtr &)> &&callback) {
    auto json = req->getJsonObject();
    std::string username = json->get("username", "").asString();
    std::string password = json->get("password", "").asString();

    auto client = drogon::app().getDbClient();
    client.get()->execSqlAsync(
            "SELECT password_hash FROM users WHERE username = $1",
            [password, callback](const Result &result) {
                std::shared_ptr<HttpResponse> response;
                if (!result.empty()) {
                    std::string storedHash = result[0]["password_hash"].as<std::string>();
                    std::string decryptedPassword = caesarCipher(storedHash, -3);
                    if (decryptedPassword == password) {
                        response = HttpResponse::newHttpResponse();
                        response->setStatusCode(k200OK);
                        response->setBody("Login successful");
                    } else {
                        response = HttpResponse::newHttpResponse();
                        response->setStatusCode(k401Unauthorized);
                        response->setBody("Login failed");
                    }
                } else {
                    response = HttpResponse::newHttpResponse();
                    response->setStatusCode(k401Unauthorized);
                    response->setBody("User not found");
                }
                callback(response);
            },
            [callback](const std::exception &e) {
                auto resp = HttpResponse::newHttpResponse();
                resp->setStatusCode(k500InternalServerError);
                resp->setBody(e.what());
                callback(resp);
            },
            username);
}

Answer 1

请记住发布您正在使用的库的链接。 检查文档后解决方案很清楚：

ENG 08 1 数据库 DbClient · drogonframework/drogon Wiki · GitHub

sql执行成功后，执行结果被Result类包装，通过结果回调函数传递给用户；如果sql执行过程中出现异常，则执行异常回调函数，用户可以从DrogonDbException对象中获取异常信息。

我们举个例子：

clientPtr->execSqlAsync("select * from users where org_name=$1",
                            [](const drogon::orm::Result &result) {
                                std::cout << result.size() << " rows selected!" << std::endl;
                                int i = 0;
                                for (auto row : result)
                                {
                                    std::cout << i++ << ": user name is " << row["user_name"].as<std::string>() << std::endl;
                                }
                            },
                            [](const DrogonDbException &e) {
                                std::cerr << "error:" << e.base().what() << std::endl;
                            },
                            "default"); ```

所以你应该这样编写代码：

            [callback](const DrogonDbException &e) {  // Correct exception handling
                auto response = HttpResponse::newHttpResponse();
                response->setStatusCode(HttpStatusCode::k500InternalServerError);
                response->setBody(e.base().what());
                callback(response);
            },