当前位置： 首页 > article >正文

利用 JSqlParser 防止 SQL 注入

article 2024/9/20 14:38:00

高手文章《jsqlparser:实现基于SQL语法分析的SQL注入攻击检查》介绍了利用 JSqlParser 防止 SQL 注入，写得很好，只不过有两个问题，代码比较复杂，我于是作了简化，只有两个类；其次检测比较严格，连子查询都禁止，我把它开放了。

最简单的 SQL 注入检测

其实，利用 JSqlParser 解析一个语句，是否成功，就能说明这个 SQL 语句有没有被注入了。

try {
    CCJSqlParserUtil.parse(sql).accept(injectionChecker);
    return true;
} catch (Exception e) {
    e.printStackTrace();
    return false;
}

如果有异常说明被注入了。这是测试例子。

SqlInjectionAnalyzer.check("SELECT * FROM mytable WHERE id = ;DROP TABLE mytable;");

高阶的 JSqlParser 检测

就是文章所介绍的方法，主要是判断表达是否为常量来分析是否注入。主要两个类ConstAnalyzer和SqlInjectionAnalyzer。

package com.ajaxjs.data.util;

import net.sf.jsqlparser.expression.BinaryExpression;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.Function;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.expression.operators.conditional.OrExpression;
import net.sf.jsqlparser.expression.operators.relational.ComparisonOperator;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.statement.select.*;
import net.sf.jsqlparser.util.TablesNamesFinder;

import java.util.regex.Pattern;

/**
 * 基于 SQL 语法对象的 SQL 注入攻击分析实现
 *
 * @author guyadong
 */
public class SqlInjectionAnalyzer extends TablesNamesFinder {
    /**
     * 危险函数名
     */
    private static final String DANGEROUS_FUNCTIONS = "(sleep|benchmark|extractvalue|updatexml|ST_LatFromGeoHash|ST_LongFromGeoHash|GTID_SUBSET|GTID_SUBTRACT|floor|ST_Pointfromgeohash"
            + "|geometrycollection|multipoint|polygon|multipolygon|linestring|multilinestring)";

//    private static final ThreadLocal<Boolean> disableSubSelect = new ThreadLocal<Boolean>() {
//        @Override
//        protected Boolean initialValue() {
//            return true;
//        }
//    };

    private final ConstAnalyzer constAnalyzer = new ConstAnalyzer();

    public SqlInjectionAnalyzer() {
        super();
        init(true);
    }

    @Override
    public void visitBinaryExpression(BinaryExpression binaryExpression) {
        if (binaryExpression instanceof ComparisonOperator) {
            if (isConst(binaryExpression.getLeftExpression()) && isConst(binaryExpression.getRightExpression()))
                /* 禁用恒等式 */
                throw new SecurityException("DISABLE IDENTICAL EQUATION " + binaryExpression);
        }

        super.visitBinaryExpression(binaryExpression);
    }

    @Override
    public void visit(AndExpression andExpression) {
        super.visit(andExpression);
        checkConstExpress(andExpression.getLeftExpression());
        checkConstExpress(andExpression.getRightExpression());
    }

    @Override
    public void visit(OrExpression orExpression) {
        super.visit(orExpression);
        checkConstExpress(orExpression.getLeftExpression());
        checkConstExpress(orExpression.getRightExpression());
    }

    @Override
    public void visit(Function function) {
        if (function.getName().matches(DANGEROUS_FUNCTIONS))
            /* 禁用危险函数 */
            throw new SecurityException("DANGEROUS FUNCTION: " + function.getName());

        super.visit(function);
    }

    @Override
    public void visit(WithItem withItem) {
//        try {
//            /* 允许 WITH 语句中的子查询 */
//            disableSubSelect.set(false);
//            super.visit(withItem);
//        } finally {
//            disableSubSelect.set(true);
//        }
    }

    @Override
    public void visit(SubSelect subSelect) {
//        if (disableSubSelect.get()) // 禁用子查询
//            throw new SecurityException("DISABLE subSelect " + subSelect);
    }

    @Override
    public void visit(Column tableColumn) {
        if (isBoolean(tableColumn))
            throw new SecurityException("DISABLE CONST BOOL " + tableColumn);

        super.visit(tableColumn);
    }

    @Override
    public void visit(PlainSelect plainSelect) {
        if (plainSelect.getSelectItems() != null) {
            for (SelectItem item : plainSelect.getSelectItems())
                item.accept(this);
        }

        if (plainSelect.getFromItem() != null)
            plainSelect.getFromItem().accept(this);

        if (plainSelect.getJoins() != null) {
            for (Join join : plainSelect.getJoins()) {
                join.getRightItem().accept(this);

                for (Expression e : join.getOnExpressions())
                    e.accept(this);
            }
        }

        if (plainSelect.getWhere() != null) {
            plainSelect.getWhere().accept(this);
            checkConstExpress(plainSelect.getWhere());
        }

        if (plainSelect.getHaving() != null)
            plainSelect.getHaving().accept(this);

        if (plainSelect.getOracleHierarchical() != null)
            plainSelect.getOracleHierarchical().accept(this);

        if (plainSelect.getOrderByElements() != null) {
            for (OrderByElement orderByElement : plainSelect.getOrderByElements())
                orderByElement.getExpression().accept(this);
        }

        if (plainSelect.getGroupBy() != null) {
            for (Expression expression : plainSelect.getGroupBy().getGroupByExpressionList().getExpressions())
                expression.accept(this);
        }
    }

    private boolean isConst(Expression expression) {
        return constAnalyzer.isConstExpression(expression);
    }

    private void checkConstExpress(Expression expression) {
        if (constAnalyzer.isConstExpression(expression))
            /* 禁用常量表达式 */
            throw new SecurityException("DISABLE CONST EXPRESSION " + expression);
    }

    private static final Pattern BOL = Pattern.compile("(true|false)", Pattern.CASE_INSENSITIVE);

    /**
     * 如果{@link Column}没有定义table,且字段名为true/false(不区分大小写)则视为布尔常量
     */
    public static boolean isBoolean(Column column) {
        return null != column && null == column.getTable() && BOL.matcher(column.getColumnName()).matches();
    }

    private static final SqlInjectionAnalyzer injectionChecker = new SqlInjectionAnalyzer();

    /**
     * SQL 注入攻击分析器
     * 对解析后的SQL对象执行注入攻击分析，有注入攻击的危险则抛出异常，
     * 并通过{@code visitor}参数提供基于AST(抽象语法树)的遍历所有节点的能力。
     *
     * @param sql SQL语句
     * @throws SecurityException 输入的SQL语句有语法错误
     */
    public static boolean check(String sql) {
        boolean allowComplexParsing = CCJSqlParserUtil.getNestingDepth(sql) <= CCJSqlParserUtil.ALLOWED_NESTING_DEPTH;

        try {
            CCJSqlParserUtil.newParser(sql).withAllowComplexParsing(allowComplexParsing).Statement().accept(injectionChecker);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
}

package com.ajaxjs.data.util;

import net.sf.jsqlparser.expression.BinaryExpression;
import net.sf.jsqlparser.expression.Expression;
import net.sf.jsqlparser.expression.Function;
import net.sf.jsqlparser.expression.operators.conditional.AndExpression;
import net.sf.jsqlparser.expression.operators.conditional.OrExpression;
import net.sf.jsqlparser.expression.operators.relational.ComparisonOperator;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.schema.Column;
import net.sf.jsqlparser.statement.select.*;
import net.sf.jsqlparser.util.TablesNamesFinder;

import java.util.regex.Pattern;

/**
 * 基于 SQL 语法对象的 SQL 注入攻击分析实现
 *
 * @author guyadong
 */
public class SqlInjectionAnalyzer extends TablesNamesFinder {
    /**
     * 危险函数名
     */
    private static final String DANGEROUS_FUNCTIONS = "(sleep|benchmark|extractvalue|updatexml|ST_LatFromGeoHash|ST_LongFromGeoHash|GTID_SUBSET|GTID_SUBTRACT|floor|ST_Pointfromgeohash"
            + "|geometrycollection|multipoint|polygon|multipolygon|linestring|multilinestring)";

//    private static final ThreadLocal<Boolean> disableSubSelect = new ThreadLocal<Boolean>() {
//        @Override
//        protected Boolean initialValue() {
//            return true;
//        }
//    };

    private final ConstAnalyzer constAnalyzer = new ConstAnalyzer();

    public SqlInjectionAnalyzer() {
        super();
        init(true);
    }

    @Override
    public void visitBinaryExpression(BinaryExpression binaryExpression) {
        if (binaryExpression instanceof ComparisonOperator) {
            if (isConst(binaryExpression.getLeftExpression()) && isConst(binaryExpression.getRightExpression()))
                /* 禁用恒等式 */
                throw new SecurityException("DISABLE IDENTICAL EQUATION " + binaryExpression);
        }

        super.visitBinaryExpression(binaryExpression);
    }

    @Override
    public void visit(AndExpression andExpression) {
        super.visit(andExpression);
        checkConstExpress(andExpression.getLeftExpression());
        checkConstExpress(andExpression.getRightExpression());
    }

    @Override
    public void visit(OrExpression orExpression) {
        super.visit(orExpression);
        checkConstExpress(orExpression.getLeftExpression());
        checkConstExpress(orExpression.getRightExpression());
    }

    @Override
    public void visit(Function function) {
        if (function.getName().matches(DANGEROUS_FUNCTIONS))
            /* 禁用危险函数 */
            throw new SecurityException("DANGEROUS FUNCTION: " + function.getName());

        super.visit(function);
    }

    @Override
    public void visit(WithItem withItem) {
//        try {
//            /* 允许 WITH 语句中的子查询 */
//            disableSubSelect.set(false);
//            super.visit(withItem);
//        } finally {
//            disableSubSelect.set(true);
//        }
    }

    @Override
    public void visit(SubSelect subSelect) {
//        if (disableSubSelect.get()) // 禁用子查询
//            throw new SecurityException("DISABLE subSelect " + subSelect);
    }

    @Override
    public void visit(Column tableColumn) {
        if (isBoolean(tableColumn))
            throw new SecurityException("DISABLE CONST BOOL " + tableColumn);

        super.visit(tableColumn);
    }

    @Override
    public void visit(PlainSelect plainSelect) {
        if (plainSelect.getSelectItems() != null) {
            for (SelectItem item : plainSelect.getSelectItems())
                item.accept(this);
        }

        if (plainSelect.getFromItem() != null)
            plainSelect.getFromItem().accept(this);

        if (plainSelect.getJoins() != null) {
            for (Join join : plainSelect.getJoins()) {
                join.getRightItem().accept(this);

                for (Expression e : join.getOnExpressions())
                    e.accept(this);
            }
        }

        if (plainSelect.getWhere() != null) {
            plainSelect.getWhere().accept(this);
            checkConstExpress(plainSelect.getWhere());
        }

        if (plainSelect.getHaving() != null)
            plainSelect.getHaving().accept(this);

        if (plainSelect.getOracleHierarchical() != null)
            plainSelect.getOracleHierarchical().accept(this);

        if (plainSelect.getOrderByElements() != null) {
            for (OrderByElement orderByElement : plainSelect.getOrderByElements())
                orderByElement.getExpression().accept(this);
        }

        if (plainSelect.getGroupBy() != null) {
            for (Expression expression : plainSelect.getGroupBy().getGroupByExpressionList().getExpressions())
                expression.accept(this);
        }
    }

    private boolean isConst(Expression expression) {
        return constAnalyzer.isConstExpression(expression);
    }

    private void checkConstExpress(Expression expression) {
        if (constAnalyzer.isConstExpression(expression))
            /* 禁用常量表达式 */
            throw new SecurityException("DISABLE CONST EXPRESSION " + expression);
    }

    private static final Pattern BOL = Pattern.compile("(true|false)", Pattern.CASE_INSENSITIVE);

    /**
     * 如果{@link Column}没有定义table,且字段名为true/false(不区分大小写)则视为布尔常量
     */
    public static boolean isBoolean(Column column) {
        return null != column && null == column.getTable() && BOL.matcher(column.getColumnName()).matches();
    }

    private static final SqlInjectionAnalyzer injectionChecker = new SqlInjectionAnalyzer();

    /**
     * SQL 注入攻击分析器
     * 对解析后的SQL对象执行注入攻击分析，有注入攻击的危险则抛出异常，
     * 并通过{@code visitor}参数提供基于AST(抽象语法树)的遍历所有节点的能力。
     *
     * @param sql SQL语句
     * @throws SecurityException 输入的SQL语句有语法错误
     */
    public static boolean check(String sql) {
        boolean allowComplexParsing = CCJSqlParserUtil.getNestingDepth(sql) <= CCJSqlParserUtil.ALLOWED_NESTING_DEPTH;

        try {
            CCJSqlParserUtil.newParser(sql).withAllowComplexParsing(allowComplexParsing).Statement().accept(injectionChecker);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
}

测试：

package com.ajaxjs.data;

import com.ajaxjs.data.util.SqlInjectionAnalyzer;
import org.junit.Test;

import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

public class TestSqlInject {
    @Test
    public void test() {
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where id in (select id from other)"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where 2=2.0 or 2 != 4"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where 1!=2.0"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where id=floor(2.0)"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where not true"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where 1 or id > 0"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where 'tom' or id > 0"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where '-2.3' "));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where 2 "));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where (3+2) "));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where  -1 IS TRUE"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where 'hello' is null "));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where '2022-10-31' and id > 0"));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where id > 0 or 1!=2.0 "));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device where id > 0 or 1 in (1,3,4) "));
        assertFalse(SqlInjectionAnalyzer.check("select * from dc_device UNION select name from other"));
        assertTrue(SqlInjectionAnalyzer.check("WITH SUB1 AS (SELECT user FROM t1) SELECT * FROM T2 WHERE id > 123 "));

        boolean check = SqlInjectionAnalyzer.check("SELECT * FROM mytable WHERE id = ;DROP TABLE mytable;");
        System.out.println(check);
    }

}

http://www.kler.cn/news/109020.html

相关文章：

  • String、StringBuffer、StringBuilder和StringJoiner
  • prometheus服务发现
  • 松下A6B伺服 马达不动问题解决
  • Photoshop（PS）2021版 安装教程（图文教程超详细）
  • git建仓库小记
  • C#__简单了解XML文档
  • 谈谈我对 Reacitive 方法的理解
  • Java开发中方法命名规范
  • NCCL后端
  • 面试测试工程师一般问什么问题？
  • 【Java】选择语句、循环语句
  • Mybatisplus 常用注解
  • Elasticsearch跨集群检索配置
  • Linux C/C++ 实现网络流量分析（性能工具）
  • 海外问卷调查是怎么做的？全方位介绍！
  • 【Git】HEAD detached from xxx 问题及解决方案
  • Hive创建分区表并插入数据
  • bat文件学习
  • 基于STM32的示波器信号发生器设计
  • LeetCode 917 仅仅反转字母 简单
  • GnuTLS recv error (-110): The TLS connection was non-properly terminated
  • C#学习相关系列之多线程（七）---Task的相关属性用法
  • 算法训练|数据流中的中位数
  • Visual Studio Code的下载与安装
  • 电脑提示由于找不到vcruntime140.dll文件,教你四个解决方案
  • 中颖单片机SH367309全套量产PCM，专用动力电池保护板开发资料
  • Postgresqlddl在事务中可以回滚，truncate时relfilenode在当前会话会改变
  • Linux命令解压多个tar.gz包
  • rust学习
  • 关于错误javax.net.ssl.SSLException: Received close_notify during handshake