I’m having problem with decoding an encrypted text.
When the encrypted message is received, Java would sometimes throw an exception below.
javax.crypto.BadPaddingException: Given final block not properly padded
at com.sun.crypto.provider.SunJCE_h.b(DashoA12275)
at com.sun.crypto.provider.SunJCE_h.b(DashoA12275)
at com.sun.crypto.provider.SunJCE_af.b(DashoA12275)
at com.sun.crypto.provider.PBEWithMD5AndDESCipher.engineDoFinal(DashoA12275)
at javax.crypto.Cipher.doFinal(DashoA12275)
at com.inv.my.encrypt.StringEncrypter.decrypt(StringEncrypter.java:206)
at com.inv.my.encrypt.EncryptDecryptMachine.decrypt(EncryptDecryptMachine.java:56)
at com.inv.my.servlet.transfer.hq.RequestStockQty.doPost(RequestStockQty.java:47)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:592)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:244)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAsPrivileged(Subject.java:517)
at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:276)
at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:162)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:262)
at org.apache.catalina.core.ApplicationFilterChain.access$0(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:171)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:167)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:172)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Thread.java:595)
My server setup is…
- Ubuntu 8.04 LTS
- Java 5
- Tomcat5.5
Weirdly enough the problem is intermittent. After restarting the server, it would go away but would come back later again which I would restart my tomcat again just to temporarily fix it.
Thanks!
Edit-Add Code:
The code I use is from…
and modified it a bit, below is my actual code. I removed the comments to make it shorter.
Thanks!
public class StringEncrypter {
Cipher ecipher;
Cipher dcipher;
public StringEncrypter(SecretKey key, String algorithm) {
try {
ecipher = Cipher.getInstance(algorithm);
dcipher = Cipher.getInstance(algorithm);
ecipher.init(Cipher.ENCRYPT_MODE, key);
dcipher.init(Cipher.DECRYPT_MODE, key);
} catch (NoSuchPaddingException e) {
System.out.println("EXCEPTION: NoSuchPaddingException");
} catch (NoSuchAlgorithmException e) {
System.out.println("EXCEPTION: NoSuchAlgorithmException");
} catch (InvalidKeyException e) {
System.out.println("EXCEPTION: InvalidKeyException");
}
}
public StringEncrypter(String passPhrase) {
setPassPhrase( passPhrase );
}
public void setPassPhrase( String passPhrase ) {
// 8-bytes Salt
byte[] salt = {
(byte)0xA9, (byte)0x9B, (byte)0xC8, (byte)0x32,
(byte)0x56, (byte)0x34, (byte)0xE3, (byte)0x03
};
// Iteration count
int iterationCount = 19;
try {
KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount);
SecretKey key = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(keySpec);
ecipher = Cipher.getInstance(key.getAlgorithm());
dcipher = Cipher.getInstance(key.getAlgorithm());
// Prepare the parameters to the cipthers
AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, iterationCount);
ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
} catch (InvalidAlgorithmParameterException e) {
System.out.println("EXCEPTION: InvalidAlgorithmParameterException");
} catch (InvalidKeySpecException e) {
System.out.println("EXCEPTION: InvalidKeySpecException");
} catch (NoSuchPaddingException e) {
System.out.println("EXCEPTION: NoSuchPaddingException");
} catch (NoSuchAlgorithmException e) {
System.out.println("EXCEPTION: NoSuchAlgorithmException");
} catch (InvalidKeyException e) {
System.out.println("EXCEPTION: InvalidKeyException");
}
}
public String encrypt(String str) {
try {
// Encode the string into bytes using utf-8
byte[] utf8 = str.getBytes("UTF8");
// Encrypt
byte[] enc = ecipher.doFinal(utf8);
// Encode bytes to base64 to get a string
return new sun.misc.BASE64Encoder().encode(enc);
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
public String decrypt(String str) {
try {
// Decode base64 to get bytes
byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);
System.out.println( "[decrypt]BASE64Decoded????? " + dec );
System.out.println( "[decrypt]Algo: " + dcipher.getAlgorithm() );
System.out.println( "[decrypt]Block Size: " + dcipher.getBlockSize() );
System.out.println( "[decrypt]Parameters: " + dcipher.getParameters().getEncoded() );
// Decrypt
byte[] utf8 = dcipher.doFinal(dec);
// Decode using utf-8
return new String(utf8, "UTF8");
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
Edit-Added Debugging Log
Encrypted: HS/uG4F/TZEN/lzX4xGvEQ==
[decrypt]BASE64Decoded????? [B@18df65f
[decrypt]Algo: PBEWithMD5AndDES
[decrypt]Block Size: 8
[decrypt]Parameters: [B@1139ac8
Better Logging Data
Encrypted: HS/uG4F/TZEN/lzX4xGvEQ==
[decrypt]BASE64Decoded????? [B@11b7a20
[decrypt]BASE64Decoded String??? 1D 2F EE 1B 81 7F 4D 91 0D FE 5C D7 E3 11 AF 11
[decrypt]BASE64Decoded Length: 16
[decrypt]Algo: PBEWithMD5AndDES
[decrypt]Block Size: 8
[decrypt]Parameters: 30 0D 04 08 A9 9B C8 32 56 34 E3 03 02 01 13
[decrypt]After decryption:68 71 53 69 64 5F 37 36 39
Decrypted: hqSid_769
Added more logging after synchronizing function
Request data: hqSid_3443
[encrypt] String??? 68 71 53 69 64 5F 33 34 34 33
[encrypt] Encrypted??? C7 02 03 2D BD F9 A6 6A 93 C0 40 48 2E 5F 2B E5
[encrypt]Encrypted �-��j��@H._+�
[encrypt]Encrypted Length 16
[encrypt]Algo: PBEWithMD5AndDES
[encrypt]Block Size: 8
[encrypt]Parameters: [B@f5cbda
received
Encrypted: xwIDLb35pmqTwEBILl8r5Q==
[decrypt]BASE64Decoded????? [B@13cd5ba
[decrypt]BASE64Decoded String??? C7 02 03 2D BD F9 A6 6A 93 C0 40 48 2E 5F 2B E5
[decrypt]BASE64Decoded Length: 16
[decrypt]Algo: PBEWithMD5AndDES
[decrypt]Block Size: 8
[decrypt]dcipher.Parameters().getEncoded(): 30 0D 04 08 A9 9B C8 32 56 34 E3 03 02 01 13
javax.crypto.BadPaddingException: Given final block not properly padded...
This code is definitely not threadsafe, and it appears to be the problem. You will need to use a different Cipher object for each thread.