（1）傳統Web應用：瀏覽器 HTTP 服務器
（2）新興移動應用：APP HTTP 服務器
從安全角度看，傳統Web應用與新興移動應用沒有本質區別
用戶提交的數據不可信是Web應用程序核心安全問題
用戶可以提交任意輸入
例如：
√ 請求參數->多次提交或者不提交
√ 修改Cookie
√ 修改HTTP信息頭
√ 請求順序->跳過或者打亂
（1）完善的異常處理
（2）監控
（3）日志：記錄重要業務、異常的詳細請求信息
建議采用：白名單
盡量避免：凈化或黑名單
（1）合法輸入：
#!sql
id=1
SELECT * FROM users WHRER id='1';
（2）惡意注入：
#!sql
id=1' or '1'='1
SELECT * FROM users WHRER id='1' or 'a'='a';
（1）不合規代碼(SQL參數拼接)
#!java
public class SQLInject {
public static void main(String[] args)throws Exception{
//正常輸入
select("1");
// 惡意輸入
select("' or 'a'='a");
}
public static void select(String id){
//聲明Connection對象
Connection con;
//驅動程序名
String driver = "com.mysql.jdbc.Driver";
//URL指向要訪問的數據庫名mydata
String url = "jdbc:mysql://localhost:3306/mybatis";
//MySQL配置時的用戶名
String user = "root";
//MySQL配置時的密碼
String password = "budi";
//遍歷查詢結果集
try {
//加載驅動程序
Class.forName(driver);
//1.getConnection()方法，連接MySQL數據庫！！
con = DriverManager.getConnection(url,user,password);
if(!con.isClosed())
System.out.println("Succeeded connecting to the Database!");
//2.創建statement類對象，用來執行SQL語句！！
Statement statement = con.createStatement();
//要執行的SQL語句
String sql = "select * from users where id='"+id+"'";
//3.ResultSet類，用來存放獲取的結果集！！
ResultSet rs = statement.executeQuery(sql);
System.out.println("-----------------");
System.out.println("執行結果如下所示:");
System.out.println("-----------------");
String age,name;
while(rs.next()){
//獲取stuname這列數據
name = rs.getString("name");
//獲取stuid這列數據
age = rs.getString("age");
//輸出結果
System.out.println(name + "\t" + age);
}
rs.close();
con.close();
} catch(ClassNotFoundException e) {
//數據庫驅動類異常處理
System.out.println("Sorry,can`t find the Driver!");
e.printStackTrace();
} catch(SQLException e) {
//數據庫連接失敗異常處理
e.printStackTrace();
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}finally{
System.out.println("數據庫數據成功獲取！！");
}
}
}
執行結果：
#!shell
SQL Paramter:1
-----------------
budi 27
-----------------
SQL Paramter:' or 'a'='a
-----------------
budi 27
budisploit 28
-----------------
（2）合規代碼（參數化查詢）
#!java
public class SQLFormat {
public static void main(String[] args)throws Exception{
select("1");
select("' or 'a'='a");
}
public static void select(String id){
//聲明Connection對象
Connection con;
//驅動程序名
String driver = "com.mysql.jdbc.Driver";
//URL指向要訪問的數據庫名mydata
String url = "jdbc:mysql://localhost:3306/mybatis";
//MySQL配置時的用戶名
String user = "root";
//MySQL配置時的密碼
String password = "budi";
//遍歷查詢結果集
try {
//加載驅動程序
Class.forName(driver);
//1.getConnection()方法，連接MySQL數據庫！！
con = DriverManager.getConnection(url,user,password);
if(!con.isClosed())
System.out.println("Succeeded connecting to the Database!");
//2.//要執行的SQL語句
String sql = "select * from users where id=?";
//3.創建statement類對象，ResultSet類，用來存放獲取的結果集！！
PreparedStatement stmt = con.prepareStatement(sql);
stmt.setString(1, id);
ResultSet rs = stmt.executeQuery();
System.out.println("-----------------");
System.out.println("執行結果如下所示:");
System.out.println("-----------------");
String age,name;
while(rs.next()){
//獲取stuname這列數據
name = rs.getString("name");
//獲取stuid這列數據
age = rs.getString("age");
//輸出結果
System.out.println(name + "\t" + age);
}
rs.close();
con.close();
} catch(ClassNotFoundException e) {
//數據庫驅動類異常處理
System.out.println("Sorry,can`t find the Driver!");
e.printStackTrace();
} catch(SQLException e) {
//數據庫連接失敗異常處理
e.printStackTrace();
}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}finally{
System.out.println("數據庫數據成功獲取！！");
}
}
}
執行結果：
#!shell
SQL Paramter:1
-----------------
budi 27
-----------------
SQL Paramter:' or 'a'='a
-----------------
-----------------
√ 采用參數查詢即預編譯方式（首選）
√ 字符串過濾
（1）合法輸入：
#!xml
quantity=1
<item>
<name>apple</name>
<price>500.0</price>
<quantity>1</quantity>
<item>
（2）惡意輸入：
#!xml
quantity=1</quantity><price>5.0</price><quantity>1
<item>
<name>apple</name>
<price>500.0</price>
<quantity>1</quantity><price>5.0</price><quantity>1</quantity>
<item>
（1）不合規代碼（未進行安全檢查）
#!java
public class XMLInject2 {
public static void main(String[] args) {
// 正常輸入
ArrayList<Map<String, String>> normalList=(ArrayList<Map<String, String>>)
ReadXML("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\inject\\normal.xml","price");
System.out.println(normalList.toString());
// 異常輸入
ArrayList<Map<String, String>> evilList=(ArrayList<Map<String, String>>)
ReadXML("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\inject\\evil.xml","price");
System.out.println(evilList.toString());
}
private static List<Map<String,String>> ReadXML(String uri,String NodeName){
try {
//創建一個解析XML的工廠對象
SAXParserFactory parserFactory=SAXParserFactory.newInstance();
//創建一個解析XML的對象
SAXParser parser=parserFactory.newSAXParser();
//創建一個解析助手類
MyHandler myhandler=new MyHandler(NodeName);
parser.parse(uri, myhandler);
return myhandler.getList();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
運行結果：
#!shell
正常輸入結果：[{price=500.0}]
惡意輸入結果：[{price=500.0}, {price=5.0}]
（2）合規代碼（利用schema安全檢查）
#!xml
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="item">
<xs:complexType>
<xs:sequence>
<xs:element name="name" type="xs:string"/>
<xs:element name="price" type="xs:decimal"/>
<xs:element name="quantity" type="xs:integer"/>
</xs:sequence>
</xs:complexType>
</xs:element>
測試代碼
#!java
public class XMLFormat{
public static void main(String[] args) {
//測試正常輸入
test("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\inject\\normal.xml");
//測試異常輸入
test("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\inject\\evil.xml");
}
private static void test(String file) {
SchemaFactory schemaFactory = SchemaFactory
.newInstance("XMLConstants.W3C_XML_SCHEMA_NS_URI");
Schema schema;
try {
schema = schemaFactory.newSchema(new File("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\inject\\schema.xsd"));
Validator validator = schema.newValidator();
validator.setErrorHandler(new ErrorHandler() {
public void warning(SAXParseException exception)
throws SAXException {
System.out.println("警告：" + exception);
}
public void fatalError(SAXParseException exception)
throws SAXException {
System.out.println("致命：" + exception);
}
public void error(SAXParseException exception) throws SAXException {
System.out.println("錯誤：" + exception);
}
});
validator.validate(new StreamSource(new File(file)));
System.out.println("解析正常");;
} catch (SAXException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
System.out.println("解析異常");
} catch (IOException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
System.out.println("解析異常");
}
}
}
運行結果：
#!shell
正常輸入........
解析正常
惡意輸入........
錯誤：org.xml.sax.SAXParseException; systemId: file:/D:/JavaWorkspace/TestInput/src/cn/com/budi/xml/inject/evil.xml; lineNumber: 7; columnNumber: 10; cvc-complex-type.2.4.d: 發現了以元素 'price' 開頭的無效內容。此處不應含有子元素。
√ 文檔類型定義（Document Type Definition，DTD）
√ XML結構化定義文件（XML Schemas Definition）
√ 白名單
（1）合法輸入：
#!xml
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE updateProfile [<!ENTITY lastname "Hello, Budi!">
<!ENTITY file SYSTEM "file:///D:/test.txt">]>
<users >
<firstname>&file</firstname>
<lastname>&lastname;</lastname>
</users>
（2）惡意輸入：
#!xml
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE updateProfile [<!ENTITY file SYSTEM "file:///D:/password.txt"> ]>
<users >
<firstname>&file;</firstname>
<lastname>&lastname;</lastname>
</users>
（1）不合規代碼（未安全檢查外部實體）
#!java
public class XXEInject {
private static void receiveXMLStream(InputStream inStream, MyDefaultHandler defaultHandler) {
// 1.獲取基于SAX的解析器的實例
SAXParserFactory factory = SAXParserFactory.newInstance();
// 2.創建一個SAXParser實例
SAXParser saxParser = factory.newSAXParser();
// 3.解析
saxParser.parse(inStream, defaultHandler);
}
public static void main(String[] args) throws FileNotFoundException, ParserConfigurationException, SAXException, IOException{
//正常輸入
receiveXMLStream(new FileInputStream("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\xxe\\inject\\normal.xml"),
new MyDefaultHandler());
//惡意輸入
receiveXMLStream(new FileInputStream("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\xxe\\inject\\evil.xml"),
new MyDefaultHandler());
}
}
運行結果：
#!shell
正常輸入，等待解析......
<firstname>XEE TEST !!</firstname>
==========================
惡意輸入，等待解析......
<firstname>OWASP BWA root/owaspbwa
Metasploitable msfadmin/msfadmin
Kali Liunx root/wangpeng
</firstname>
（2）合規代碼（安全檢查外部實體）
#!java
public class CustomResolver implements EntityResolver{
public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException{
//System.out.println("PUBLIC:"+publicId);
//System.out.println("SYSTEM:"+systemId);
System.out.println("引用實體檢測....");
String entityPath = "file:///D:/test.txt";
if (systemId.equals(entityPath)){
System.out.println("合法解析："+systemId);
return new InputSource(entityPath);
}else{
System.out.println("非法實體："+systemId);
return new InputSource();
}
}
}
測試代碼
#!java
public class XXEFormat {
private static void receiveXMLStream(InputStream inStream, MyDefaultHandler defaultHandler) {
// 獲取基于SAX的解析器的實例
SAXParserFactory factory = SAXParserFactory.newInstance();
// 創建一個SAXParser實例
SAXParser saxParser;
try {
saxParser = factory.newSAXParser();
//創建讀取工具
XMLReader reader = saxParser.getXMLReader();
reader.setEntityResolver(new CustomResolver());
reader.setErrorHandler(defaultHandler);
InputSource is = new InputSource(inStream);
reader.parse(is);
System.out.println("\t成功解析完成!");
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
System.out.println("\t非法解析!");
} catch (SAXException e) {
// TODO Auto-generated catch block
System.out.println("\t非法解析!");
} catch (IOException e) {
// TODO Auto-generated catch block
System.out.println("\t非法解析!");
}
}
public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException{
//正常輸入
System.out.println("正常輸入，等待解析......");
receiveXMLStream(new FileInputStream("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\xxe\\inject\\normal.xml"),
new MyDefaultHandler());
System.out.println("==========================");
//惡意輸入
System.out.println("惡意輸入，等待解析......");
receiveXMLStream(new FileInputStream("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\xml\\xxe\\inject\\evil.xml"),
new MyDefaultHandler());
}
}
運行結果：
#!shell
正常輸入，等待解析......
引用實體檢測....
合法解析：file:///D:/test.txt
成功解析完成!
==========================
惡意輸入，等待解析......
引用實體檢測....
非法實體：file:///D:/password.txt
非法解析!
√ 白名單
（1）正常輸入：
#!shell
dir
（2）惡意輸入：
#!shell
dir & ipconfig & net user budi budi /add & net localgroup Administrators admin /add
（1）非合規Window命令注入
#!java
public class OrderWinFault {
public static void main(String[] args) throws Exception{
//正常命令
runOrder("dir");
//惡意命令
runOrder("dir & ipconfig & net user budi budi /add & net localgroup Administrators admin /add");
}
private static void runOrder(String order) throws IOException, InterruptedException{
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec("cmd.exe /C "+order);
int result = proc.waitFor();
if(result !=0){
System.out.println("process error: "+ result);
}
InputStream in = (result == 0)? proc.getInputStream() : proc.getErrorStream();
BufferedReader reader=new BufferedReader(new InputStreamReader(in));
StringBuffer buffer=new StringBuffer();
String line;
while((line = reader.readLine())!=null){
buffer.append(line+"\n");
}
System.out.print(buffer.toString());
}
}
（2）非合規的Linux注入命令
#!java
public class OrderLinuxFault {
public static void main(String[] args) throws Exception{
// 正常命令
runOrder("ls");
// 惡意命令
runOrder(" ls & ifconfig");
}
private static void runOrder(String order) throws IOException, InterruptedException{
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(new String [] {"sh", "-c", "ls "+order});
int result = proc.waitFor();
if(result !=0){
System.out.println("process error: "+ result);
}
InputStream in = (result == 0)? proc.getInputStream() : proc.getErrorStream();
BufferedReader reader=new BufferedReader(new InputStreamReader(in));
StringBuffer buffer=new StringBuffer();
String line;
while((line = reader.readLine())!=null){
buffer.append(line+"\n");
}
System.out.print(buffer.toString());
}
}
（3）合規編碼（對命令安全檢查）
#!java
public class OrderFormat {
public static void main(String[] args) throws Exception{
runOrder("dir");
runOrder("dir & ipconfig & net user budi budi /add & net localgroup Administrators admin /add");
}
private static void runOrder(String order) throws IOException, InterruptedException{
if (!Pattern.matches("[0-9A-Za-z@.]+", order)){
System.out.println("存在非法命令");
return;
}
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec("cmd.exe /C "+order);
int result = proc.waitFor();
if(result !=0){
System.out.println("process error: "+ result);
}
InputStream in = (result == 0)? proc.getInputStream() : proc.getErrorStream();
BufferedReader reader=new BufferedReader(new InputStreamReader(in));
StringBuffer buffer=new StringBuffer();
String line;
while((line = reader.readLine())!=null){
buffer.append(line+"\n");
}
System.out.print(buffer.toString());
}
}
√ 白名單
√ 嚴格權限限制
√ 采用命令標號
（1）合法輸入：
#!shell
普通壓縮比文件normal.zip
（2）惡意輸入：
#!shell
高壓縮比文件evil.zip
#!java
public class ZipFault {
static final int BUFFER = 512;
public static void main(String[] args) throws IOException{
System.out.println("正常壓縮文件.......");
checkzip("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\zip\\normal.zip");
System.out.println("惡意壓縮文件.......");
checkzip("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\zip\\evil.zip");
}
private static void checkzip(String filename) throws IOException{
BufferedOutputStream dest = null;
FileInputStream fls = new FileInputStream(filename);
ZipInputStream zis = new ZipInputStream(new BufferedInputStream(fls));
ZipEntry entry;
long begin = System.currentTimeMillis();
while ((entry = zis.getNextEntry()) != null){
System.out.println("Extracting:" + entry+"\t解壓后大小："+entry.getSize());
int count;
byte data[] = new byte[BUFFER];
FileOutputStream fos = new FileOutputStream("D:/"+entry.getName());
dest = new BufferedOutputStream(fos, BUFFER);
while ((count = zis.read(data, 0, BUFFER))!=-1){
dest.write(data,0, count);
}
dest.flush();
dest.close();
}
zis.close();
long end = System.currentTimeMillis();
System.out.println("解壓縮執行耗時:" + (end - begin) + " 豪秒");
}
}
運行結果：
#!shell
正常壓縮文件.......
Extracting:normal.txt 解壓后大小：17496386
解壓縮執行耗時:382 豪秒
惡意壓縮文件.......
Extracting:evil.txt 解壓后大小：2000000000
解壓縮執行耗時:25911 豪秒
（2）合規代碼
#!java
public class ZipFormat {
static final int BUFFER = 512;
static final int TOOBIG = 0x640000;
public static void main(String[] args) throws IOException{
checkzip("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\zip\\normal.zip");
checkzip("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\zip\\evil.zip");
}
private static void checkzip(String filename) throws IOException{
BufferedOutputStream dest = null;
FileInputStream fls = new FileInputStream(filename);
ZipInputStream zis = new ZipInputStream(new BufferedInputStream(fls));
ZipEntry entry;
long begin = System.currentTimeMillis();
while ((entry = zis.getNextEntry()) != null){
System.out.println("Extracting:" + entry+"\t解壓后大小："+entry.getSize());
if (entry.getSize() > TOOBIG){
System.out.println("壓縮文件過大");
break;
}
if (entry.getSize() == -1){
System.out.println("文件大小異常");
}
int count;
byte data[] = new byte[BUFFER];
FileOutputStream fos = new FileOutputStream("D:/"+entry.getName());
dest = new BufferedOutputStream(fos, BUFFER);
while ((count = zis.read(data, 0, BUFFER))!=-1){
dest.write(data,0, count);
}
dest.flush();
dest.close();
}
zis.close();
long end = System.currentTimeMillis();
System.out.println("解壓縮執行耗時:" + (end - begin) + " 豪秒");
}
}
運行結果：
#!shell
正常文件.........
Extracting:normal.txt 解壓后大小：17496386
解壓縮執行耗時:378 豪秒
===================
惡意文件.........
Extracting:evil.txt 解壓后大小：2000000000
壓縮文件過大
解壓縮執行耗時:0 豪秒
√ 解壓前檢查解壓后文件大小
（1）合法輸入
#!shell
search=error
拼接后
#!shell
(.*? +public\\[\\d+\\]+.*error.*)
（2）惡意輸入
#!shell
search=.*)|(.*
拼接后
#!shell
(.*? +public\\[\\d+\\]+.*.*)|(.*.*)
（1）非合規代碼（未進行安全檢查）
#!java
public class RegexFault {
/**
* 以行為單位讀取文件，常用于讀面向行的格式化文件
*/
public static void readFileByLines(String filename,String search) {
File file = new File(filename);
BufferedReader reader = null;
String regex ="(.*? +public\\[\\d+\\] +.*"+search+".*)";
System.out.println("正則表達式："+regex);
try {
reader = new BufferedReader(new FileReader(file));
String tempString = null;
int line = 1;
System.out.println("查找開始......");
// 一次讀入一行，直到讀入null為文件結束
while ((tempString = reader.readLine()) != null) {
//System.out.println("line " + line + ": " + tempString);
if(Pattern.matches(regex, tempString)){
// 顯示行號
System.out.println("line " + line + ": " + tempString);
}
line++;
}
reader.close();
System.out.println("查找結束....");
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e1) {
}
}
}
}
public static void main(String[] args){
//正常輸入
readFileByLines("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\regex\\regex.log","error");
//惡意輸入
readFileByLines("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\regex\\regex.log",".*)|(.*");
}
}
運行結果：
#!shell
正常輸入......
正則表達式：(.*? +public\[\d+\] +.*error.*)
line 5: 10:48:08 public[48964] Backup failed with error: 19
============================
惡意輸入......
正則表達式：(.*? +public\[\d+\] +.*.*)|(.*.*)
line 1: 10:47:03 private[423] Successful logout name: budi ssn: 111223333
line 2: 10:47:04 public[48964] Failed to resolve network service
line 3: 10:47:04 public[1] (public.message[49367]) Exited with exit code: 255
line 4: 10:47:43 private[423] Successful login name: budisploit ssn: 444556666
line 5: 10:48:08 public[48964] Backup failed with error: 19
（2）合規代碼（進行安全檢查）
#!java
public class RegexFormat {
/**
* 檢測是否存在非法字符
* @param search
*/
private static boolean validate(String search){
for (int i = 0; i< search.length(); i++){
char ch = search.charAt(i);
if(!(Character.isLetterOrDigit(ch) || ch ==' ' || ch =='\'')){
System.out.println("存在非法字符，查找失敗....");
return false;
}
}
return true;
}
/**
* 以行為單位讀取文件，常用于讀面向行的格式化文件
*/
public static void readFileByLines(String filename,String search) {
if(!validate(search)){
return;
}
File file = new File(filename);
BufferedReader reader = null;
String regex ="(.*? +public\\[\\d+\\] +.*"+search+".*)";
System.out.println("正則表達式："+regex);
try {
reader = new BufferedReader(new FileReader(file));
String tempString = null;
int line = 1;
System.out.println("查找開始......");
// 一次讀入一行，直到讀入null為文件結束
while ((tempString = reader.readLine()) != null) {
//System.out.println("line " + line + ": " + tempString);
if(Pattern.matches(regex, tempString)){
// 顯示行號
System.out.println("line " + line + ": " + tempString);
}
line++;
}
reader.close();
System.out.println("查找結束....");
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e1) {
}
}
}
}
public static void main(String[] args){
//正常輸入
System.out.println("正常輸入......");
readFileByLines("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\regex\\regex.log","error");
System.out.println("============================");
//惡意輸入
System.out.println("惡意輸入......");
readFileByLines("D:\\JavaWorkspace\\TestInput\\src\\cn\\com\\budi\\regex\\regex.log",".*)|(.*");
}
}
運行結果：
#!shell
============================
正常輸入......
正則表達式：(.*? +public\[\d+\] +.*error.*)
line 5: 10:48:08 public[48964] Backup failed with error: 19
============================
惡意輸入......
存在非法字符，查找失敗....
√ 白名單
（1）日志記錄
正常輸入：
#!shell
budi
日志記錄：
#!shell
User Login Successed for: budi
惡意輸入：
#!shell
budi \nUser Login Successed for: administrator
日志記錄：
#!shell
User Login Failed for: budi
User Login Successed for: administrator
（2）更新用戶名
正常輸入：
#!sql
username=budi
SQL查詢：
#!sql
SELECT * FROM users WHRER id='budi';
惡意輸入：
#!sql
username=budi' or 'a'='a
SQL查詢：
#!sql
SELECT * FROM users WHRER id='budi' or 'a'='a';
（1）非合規代碼（未安全檢查）
#!java
public class LogFault {
private static void writeLog( boolean isLogin,String username){
if(isLogin){
System.out.println("User Login Successed for: "+username);
}else{
System.out.println("User Login Failed for: "+username);
}
}
public static void main(String[] args){
String test1= "budi";
System.out.println("正常用戶登錄成功后，記錄日志.....");
//正常用戶登錄成功后，記錄日志
writeLog(true, test1);
//惡意用戶登錄失敗，記錄日志
String test2 = "budi \nUser Login Successed for: administrator";
System.out.println("惡意用戶登錄失敗，記錄日志.....");
writeLog(false, test2);
}
}
運行結果：
#!shell
正常用戶登錄成功后，記錄日志.....
User Login Successed for: budi
惡意用戶登錄失敗，記錄日志.....
User Login Failed for: budi
User Login Successed for: administrator
（2）合規代碼（安全檢查）
#!java
public class LoginFormat {
private static void writeLog( boolean isLogin,String username){
if(!Pattern.matches("[A-Za-z0-9_]+", username)){
System.out.println("User Login Failed for Unknow User");
}else if(isLogin){
System.out.println("User Login Successed for: "+username);
}else{
System.out.println("User Login Failed for: "+username);
}
}
public static void main(String[] args){
String test1= "budi";
System.out.println("正常用戶登錄成功后，記錄日志.....");
writeLog(true, test1);
String test2 = "budi \nUser Login Successed for: administrator";
System.out.println("惡意用戶登錄失敗，記錄日志.....");
writeLog(false, test2);
}
}
運行結果：
#!shell
正常用戶登錄成功后，記錄日志.....
User Login Successed for: budi
惡意用戶登錄失敗，記錄日志.....
User Login Failed for Unknow User
√ 先檢測用戶輸入，強烈建議直接拒絕帶非法字符的數據
（1）正常輸入：
#!shell
john.txt
（2）惡意輸入：
#!shell
../../a.txt"
（1）非合規代碼（未安全檢查）
#!java
public class PathFault {
public static void main(String[] args) throws IOException{
System.out.println("合法輸入.......");
readFile("john.txt");
System.out.println("\n惡意輸入.......");
readFile("../../a.txt");
}
private static void readFile(String path) throws IOException{
File f = new File("F://passwords//"+path);
String absPath = f.getAbsolutePath();
FileOutputStream fls = new FileOutputStream(f);
System.out.print("絕對路徑："+absPath);
if(!isInSecureDir(Paths.get(absPath))){
System.out.println("->非安全路徑");
return;
}
System.out.print("->安全路徑");
}
private static boolean isInSecureDir(Path path){
if(!path.startsWith("F://passwords//")){
return false;
};
return true;
}
}
運行結果：
#!shell
合法輸入.......
絕對路徑：F:\passwords\john.txt->安全路徑
惡意輸入.......
絕對路徑：F:\passwords\..\..\a.txt->安全路徑
（2）合規代碼（先統一路徑表示）
#!java
public class PathFormat {
public static void main(String[] args) throws IOException{
System.out.println("合法輸入.......");
readFile("john.txt");
System.out.println("/n惡意輸入.......");
readFile("../../a.txt");
}
private static void readFile(String path) throws IOException{
File f = new File("F://passwords//"+path);
String canonicalPath = f.getCanonicalPath();
System.out.println("絕對路徑"+canonicalPath);
FileInputStream fls = new FileInputStream(f);
if(!isInSecureDir(Paths.get(canonicalPath))){
System.out.print("非安全路徑");
return;
}
System.out.print("安全路徑");
}
private static boolean isInSecureDir(Path path){
if(!path.startsWith("F://passwords//")){
return false;
};
return true;
}
}
運行結果：
#!shell
合法輸入.......
絕對路徑F:\passwords\john.txt->安全路徑
惡意輸入.......
絕對路徑F:\a.txt->非安全路徑
√ 嚴格的權限限制->安全管理器
√ getCanonicalPath()在所有平臺上對所有別名、快捷方式、符號鏈接采用統一的解析。
（1）正常輸入：
11
正常拼接：
#!shell
System.out.printf("11 did not match! HINT: It was issued on %1$te rd of some month\n", c);
（2）惡意輸入：
#!shell
%1$tm或%1$te或%1$tY
惡意拼接：
#!shell
System.out.printf("%1$tm did not match! HINT: It was issued on %1$te rd of some month\n", c);
（1）非合規代碼：
#!java
public class DateFault {
static Calendar c = new GregorianCalendar(2016, GregorianCalendar.MAY, 23);
public static void main(String[] args){
//正常用戶輸入
System.out.println("正常用戶輸入.....");
format("11");
System.out.println("非正常輸入獲取月份.....");
format("%1$tm");
System.out.println("非正常輸入獲取日.....");
format("%1$te");
System.out.println("非正常輸入獲取年份.....");
format("%1$tY");
}
private static void format(String month){
System.out.printf(month+" did not match! HINT: It was issued on %1$te rd of some month\n", c);
}
}
運行結果：
#!shell
11 did not match! HINT: It was issued on 23rd of some month
非正常輸入獲取月份.....
05 did not match! HINT: It was issued on 23rd of some month
非正常輸入獲取日.....
23 did not match! HINT: It was issued on 23rd of some month
非正常輸入獲取年份.....
2016 did not match! HINT: It was issued on 23rd of some month
（2）合規代碼：
#!java
public class DateFormat {
static Calendar c = new GregorianCalendar(2016, GregorianCalendar.MAY, 23);
public static void main(String[] args){
//正常用戶輸入
System.out.println("正常用戶輸入.....");
format("11");
System.out.println("非正常輸入獲取月份.....");
format("%1$tm");
System.out.println("非正常輸入獲取日.....");
format("%1$te");
System.out.println("非正常輸入獲取年份.....");
format("%1$tY");
}
private static void format(String month){
System.out.printf("%s did not match! HINT: It was issued on %1$te rd of some month\n", month, c);
}
}
運行結果：
#!shell
正常用戶輸入.....
11 did not match! HINT: It was issued on
Exception in thread "main" java.util.IllegalFormatConversionException: e != java.lang.String
√ 對用戶輸入進行安全檢查
√ 在格式字符串中，杜絕使用用戶輸入參數
（1）合法輸入：
#!shell
username=budi
（2）惡意輸入一：
#!shell
username=/><script>alert(1)</script>
username=/\uFE65\uFE64script\uFE65alert(1) \uFE64/script\uFE65
（3）惡意輸入二：
#!shell
username=A\uD8AB
username=A?
（1）非合規代碼（先檢查再統一編碼）
#!java
public class EncodeFault {
public static void main(String[] args){
System.out.println("未編碼的非法字符");
check("/><script>alert(2)</script>");
System.out.println("Unicode編碼的非法字符");
check("/\uFE65\uFE64script\uFE65alert(1) \uFE64/script\uFE65");
}
public static void check(String s){
Pattern pattern = Pattern.compile("[<>]");
Matcher matcher = pattern.matcher(s);
if (matcher.find()){
System.out.println(s+"->存在非法字符");
}else{
System.out.println(s+"->合法字符");
}
s = Normalizer.normalize(s, Form.NFC);
}
}
運行結果：
#!shell
未編碼的非法字符
/><script>alert(2)</script>->存在非法字符
Unicode編碼的非法字符
/﹥﹤script﹥alert(1) ﹤/script﹥->合法字符
（3）合規代碼（先統一編碼再檢查）
#!java
public class EncodeFormat {
public static void main(String[] args){
System.out.println("未編碼的非法字符");
check("/><script>alert(2)</script>");
System.out.println("Unicode編碼的非法字符");
check("/\uFE65\uFE64script\uFE65alert(1)\uFE64/script\uFE65");
}
public static void check(String s){
s = Normalizer.normalize(s, Form.NFC);
// 用\uFFFD替代非Unicode編碼字符
s = s.replaceAll("^\\p{ASCII}]", "\uFFFD");
Pattern pattern = Pattern.compile("[<>]");
Matcher matcher = pattern.matcher(s);
if (matcher.find()){
System.out.println(s+"->存在非法字符");
}else{
System.out.println(s+"->合法字符");
}
}
}
運行結果：
#!shell
未編碼的非法字符
/><script>alert(2)</script>->存在非法字符
Unicode編碼的非法字符
/><script>alert(1)</script>->存在非法字符
√ 先按指定編碼方式標準化字符串，再檢查非法輸入
√ 檢測非法字符
參考文獻: 《Java安全編碼標準》