password hash cheching

database/mysql/mysql.cpp

@@ -10,21 +10,17 @@
 
 #include "statement.h"
 #include "transaction.h"
+#include "database/exceptions.h"
 
 constexpr const char* versionQuery = "SELECT value FROM system WHERE `key` = 'version'";
 constexpr const char* updateQuery = "UPDATE system SET `value` = ? WHERE `key` = 'version'";
 constexpr const char* registerQuery = "INSERT INTO accounts (`login`, `type`, `password`) VALUES (?, 1, ?)";
 constexpr const char* lastIdQuery = "SELECT LAST_INSERT_ID() AS id";
 constexpr const char* assignRoleQuery = "INSERT INTO roleBindings (`account`, `role`) SELECT ?, roles.id FROM roles WHERE roles.name = ?";
+constexpr const char* selectHash = "SELECT password FROM accounts where login = ?";
 
 static const std::filesystem::path buildSQLPath = "database";
 
-struct ResDeleter {
-    void operator () (MYSQL_RES* res) {
-        mysql_free_result(res);
-    }
-};
-
 MySQL::MySQL():
     DBInterface(Type::mysql),
     connection(),
@@ -231,7 +227,11 @@ unsigned int MySQL::registerAccount(const std::string& login, const std::string&
     std::string h = hash;
     addAcc.bind(l.data(), MYSQL_TYPE_STRING);
     addAcc.bind(h.data(), MYSQL_TYPE_STRING);
-    addAcc.execute();
+    try {
+        addAcc.execute();
+    } catch (const Duplicate& dup) {
+        throw DuplicateLogin(dup.what());
+    }
 
     unsigned int id = lastInsertedId();
     static std::string defaultRole("default");
@@ -245,6 +245,24 @@ unsigned int MySQL::registerAccount(const std::string& login, const std::string&
     return id;
 }
 
+std::string MySQL::getAccountHash(const std::string& login) {
+    std::string l = login;
+    MYSQL* con = &connection;
+
+    Statement getHash(con, selectHash);
+    getHash.bind(l.data(), MYSQL_TYPE_STRING);
+    getHash.execute();
+
+    std::vector<std::vector<std::string>> result = getHash.fetchResult();
+    if (result.empty())
+        throw NoLogin("Couldn't find login " + l);
+
+    if (result[0].empty())
+        throw std::runtime_error("Error with the query \"selectHash\"");
+
+    return result[0][0];
+}
+
 unsigned int MySQL::lastInsertedId() {
     MYSQL* con = &connection;
     int result = mysql_query(con, lastIdQuery);

database/mysql/mysql.h

@@ -15,6 +15,8 @@
 class MySQL : public DBInterface {
     class Statement;
     class Transaction;
+
+
 public:
     MySQL();
     ~MySQL() override;
@@ -29,6 +31,7 @@ public:
     void setVersion(uint8_t version) override;
 
     unsigned int registerAccount(const std::string& login, const std::string& hash) override;
+    std::string getAccountHash(const std::string& login) override;
 
 private:
     void executeFile(const std::filesystem::path& relativePath);
@@ -40,4 +43,10 @@ protected:
     std::string login;
     std::string password;
     std::string database;
+
+struct ResDeleter {
+    void operator () (MYSQL_RES* res) {
+        mysql_free_result(res);
+    }
+};
 };

database/mysql/statement.cpp

@@ -5,6 +5,10 @@
 
 #include <cstring>
 
+#include "mysqld_error.h"
+
+#include "database/exceptions.h"
+
 static uint64_t TIME_LENGTH = sizeof(MYSQL_TIME);
 
 MySQL::Statement::Statement(MYSQL* connection, const char* statement):
@@ -44,11 +48,68 @@ void MySQL::Statement::bind(void* value, enum_field_types type, bool usigned) {
 }
 
 void MySQL::Statement::execute() {
-    int result = mysql_stmt_bind_param(stmt.get(), param.data());
+    MYSQL_STMT* raw = stmt.get();
+    int result = mysql_stmt_bind_param(raw, param.data());
     if (result != 0)
-        throw std::runtime_error(std::string("Error binding statement: ") + mysql_stmt_error(stmt.get()));
+        throw std::runtime_error(std::string("Error binding statement: ") + mysql_stmt_error(raw));
 
-    result = mysql_stmt_execute(stmt.get());
-    if (result != 0)
-        throw std::runtime_error(std::string("Error executing statement: ") + mysql_stmt_error(stmt.get()));
+    result = mysql_stmt_execute(raw);
+    if (result != 0) {
+        int errcode = mysql_stmt_errno(raw);
+        std::string text = mysql_stmt_error(raw);
+        switch (errcode) {
+            case ER_DUP_ENTRY:
+                throw Duplicate("Error executing statement: " + text);
+            default:
+                throw std::runtime_error("Error executing statement: " + text);
+        }
+    }
 }
+
+std::vector<std::vector<std::string>> MySQL::Statement::fetchResult() {
+    MYSQL_STMT* raw = stmt.get();
+    if (mysql_stmt_store_result(raw) != 0)
+        throw std::runtime_error(std::string("Error fetching statement result: ") + mysql_stmt_error(raw));   //TODO not sure if it's valid here
+
+    MYSQL_RES* meta = mysql_stmt_result_metadata(raw);
+    if (meta == nullptr)
+        throw std::runtime_error(std::string("Error fetching statement result: ") + mysql_stmt_error(raw));   //TODO not sure if it's valid here
+
+    std::unique_ptr<MYSQL_RES, ResDeleter> mt(meta);
+    unsigned int numColumns = mysql_num_fields(meta);
+    MYSQL_BIND bind[numColumns];
+    memset(bind, 0, sizeof(bind));
+
+    std::vector<std::string> line(numColumns);
+    std::vector<long unsigned int> lengths(numColumns);
+    for (unsigned int i = 0; i < numColumns; ++i) {
+        MYSQL_FIELD *field = mysql_fetch_field_direct(meta, i);
+
+        switch (field->type) {
+            case MYSQL_TYPE_STRING:
+            case MYSQL_TYPE_VAR_STRING:
+            case MYSQL_TYPE_VARCHAR:
+                break;
+            default:
+                throw std::runtime_error("Unsupported data fetching statement result " + std::to_string(field->type));
+        }
+        line[i].resize(field->length);
+        bind[i].buffer_type = field->type;
+        bind[i].buffer = line[i].data();
+        bind[i].buffer_length = field->length;
+        bind[i].length = &lengths[i];
+    }
+
+    if (mysql_stmt_bind_result(raw, bind) != 0)
+        throw std::runtime_error(std::string("Error binding on fetching statement result: ") + mysql_stmt_error(raw));
+
+    std::vector<std::vector<std::string>> result;
+    while (mysql_stmt_fetch(raw) == 0) {
+        std::vector<std::string>& row = result.emplace_back(numColumns);
+        for (unsigned int i = 0; i < numColumns; ++i)
+            row[i] = std::string(line[i].data(), lengths[i]);
+    }
+
+    return result;
+}
+

database/mysql/statement.h

@@ -18,6 +18,7 @@ public:
 
     void bind(void* value, enum_field_types type, bool usigned = false);
     void execute();
+    std::vector<std::vector<std::string>> fetchResult();
 
 private:
     std::unique_ptr<MYSQL_STMT, STMTDeleter> stmt;

database/mysql/transaction.cpp

@@ -1,3 +1,6 @@
+//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
+//  SPDX-License-Identifier: GPL-3.0-or-later
+
 #include "transaction.h"
 
 MySQL::Transaction::Transaction(MYSQL* connection):

database/mysql/transaction.h

@@ -1,3 +1,6 @@
+//  SPDX-FileCopyrightText: 2023 Yury Gubich <blue@macaw.me>
+//  SPDX-License-Identifier: GPL-3.0-or-later
+
 #pragma once
 
 #include "mysql.h"