AES256 암호화 복호화시 오류 Invalid AES key length 해결방법

떠돌이개발자Apr 25, 2023

AES256 암화코드를 사용하여 Encript 중에 오류가 발생되었다.

오류내용은 AES Key 길이 문제이다.

java.security.InvalidKeyException: Invalid AES key length: 21 bytes
	at com.sun.crypto.provider.AESCrypt.init(AESCrypt.java:87)
	at com.sun.crypto.provider.GaloisCounterMode.init(GaloisCounterMode.java:298)
	at com.sun.crypto.provider.CipherCore.init(CipherCore.java:589)
	at com.sun.crypto.provider.CipherCore.init(CipherCore.java:467)
	at com.sun.crypto.provider.AESCipher.engineInit(AESCipher.java:313)
	at javax.crypto.Cipher.implInit(Cipher.java:801)
	at javax.crypto.Cipher.chooseProvider(Cipher.java:863)
	at javax.crypto.Cipher.init(Cipher.java:1248)
	at javax.crypto.Cipher.init(Cipher.java:1185)
	at com.test.util.AES256Util.aesEncode(AES256Util.java:59)
	at ubsales.biz.login.controller.LoginController.loginMain(LoginController.java:155)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:743)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:672)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:82)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:933)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:867)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:951)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:853)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:827)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:743)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:485)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:410)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:337)
	at org.springframework.security.web.firewall.RequestWrapper$FirewalledRequestAwareRequestDispatcher.forward(RequestWrapper.java:132)
	at org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler.onAuthenticationFailure(SimpleUrlAuthenticationFailureHandler.java:65)
	at ubsales.core.handler.AuthenticationFailureHandler.onAuthenticationFailure(AuthenticationFailureHandler.java:54)
	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.unsuccessfulAuthentication(AbstractAuthenticationProcessingFilter.java:355)
	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:225)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.authentication.preauth.AbstractPreAuthenticatedProcessingFilter.doFilter(AbstractPreAuthenticatedProcessingFilter.java:94)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:125)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:343)
	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:260)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:106)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:748)

AES 예제 코드

import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class AES256 {

    public static String alg = "AES/CBC/PKCS5Padding";
    private final String key = "01234567890123456789012345678901";
    private final String iv = key.substring(0, 16); // 16byte

    public String encrypt(String text) throws Exception {
        Cipher cipher = Cipher.getInstance(alg);
        SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
        IvParameterSpec ivParamSpec = new IvParameterSpec(iv.getBytes());
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParamSpec);

        byte[] encrypted = cipher.doFinal(text.getBytes("UTF-8"));
        return Base64.getEncoder().encodeToString(encrypted);
    }

    public String decrypt(String cipherText) throws Exception {
        Cipher cipher = Cipher.getInstance(alg);
        SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
        IvParameterSpec ivParamSpec = new IvParameterSpec(iv.getBytes());
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivParamSpec);

        byte[] decodedBytes = Base64.getDecoder().decode(cipherText);
        byte[] decrypted = cipher.doFinal(decodedBytes);
        return new String(decrypted, "UTF-8");
    }

}

import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;

import com.itextpdf.text.pdf.codec.Base64;
    
public class AES256Helper
{	
	public AES256Helper(String key) {
    	this.keySpec = new SecretKeySpec(key.getBytes(), "AES");
    }    
 
    public String encode(String str) throws java.io.UnsupportedEncodingException, 
                                                    NoSuchAlgorithmException, 
                                                    NoSuchPaddingException, 
                                                    InvalidKeyException, 
                                                    InvalidAlgorithmParameterException, 
                                                    IllegalBlockSizeException, 
                                                    BadPaddingException {
    	
    	Cipher c = Cipher.getInstance("AES/GCM/NoPadding");
    	c.init(Cipher.ENCRYPT_MODE, keySpec); // AES/ECB/PKCS5Padding
 
        byte[] encrypted = c.doFinal(str.getBytes(ComnConst.UTF_8_UPPER));
        String enStr = new String(Base64.encodeBytes(encrypted));
 
        return enStr;
    }
 
    public String decode(String str) throws java.io.UnsupportedEncodingException,
                                                        NoSuchAlgorithmException,
                                                        NoSuchPaddingException, 
                                                        InvalidKeyException, 
                                                        InvalidAlgorithmParameterException,
                                                        IllegalBlockSizeException, 
                                                        BadPaddingException {
        Cipher c = Cipher.getInstance("AES/GCM/NoPadding");
    	c.init(Cipher.DECRYPT_MODE, keySpec); // AES/ECB/PKCS5Padding
        
        byte[] byteStr = Base64.decode(str);
 
        return new String(c.doFinal(byteStr),ComnConst.UTF_8_UPPER);
    }
}

public class TestAES {

    public static void main(String[] args) throws Exception {

        AES256 aes256 = new AES256();
        String text = "Hello World";
        String cipherText = aes256.encrypt(text);
        System.out.println(text);
        System.out.println(cipherText);
        System.out.println(aes256.decrypt(cipherText));

    }

}

[오류해결 방법]

AES 암호화 처리시 사용하는 키값의 길이는 반드시 16, 24, 32 byte 중에 하나로 고정해야한다.

[연관 자료]

[REFERENCE]

How to fix Invalid AES key length?

I am working on a text encryption and decryption project (following Struts 2) Whenever I enter the password and the plain text I get a Invalid AES Key Length error. The Service Class package com.

stackoverflow.com

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