Input length must be multiple of 8 when decrypting with padded cipher

java.lang.RuntimeException: javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
        at us.pinguo.flume.hdfs.ext.source.BlobExtHandler.checkGeo(BlobExtHandler.java:399)
        at us.pinguo.flume.hdfs.ext.source.BlobExtHandler.processEvent(BlobExtHandler.java:232)
        at us.pinguo.flume.hdfs.ext.source.BlobExtHandler.getEvents(BlobExtHandler.java:140)
        at us.pinguo.flume.hdfs.ext.source.HTTPSource$FlumeHTTPServlet.doPost(HTTPSource.java:252)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
        at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:401)
        at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
        at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
        at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:767)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
        at org.mortbay.jetty.Server.handle(Server.java:326)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
        at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:945)
        at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:756)
        at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
        at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
        at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
        at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
Caused by: javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
        at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:750)
        at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:676)
        at com.sun.crypto.provider.DESCipher.engineDoFinal(DESCipher.java:314)
        at javax.crypto.Cipher.doFinal(Cipher.java:2087)
        at us.pinguo.flume.hdfs.ext.utils.DES.decryptDES(DES.java:49)
        at us.pinguo.flume.hdfs.ext.utils.DESHelperV2.decryptDESBase64(DESHelperV2.java:96)
        at us.pinguo.flume.hdfs.ext.source.BlobExtHandler.checkGeo(BlobExtHandler.java:386)
        ... 19 more



解决方案
you are calling doFinal multiple times. or at least trying to.

when you read data, not all data arrives or is read into the buffer at once. so you decrypt some and then read again. that is all ok.

but when you do that, you are calling doFinal each time, instead of update. this is wrong and is the cause of the error. instead, replace doFinal with update and then add an extra doFinal once you have finished reading all data (there is a doFinal() that takes no arguments for exactly this reason).

see http://docs.oracle.com/javase/7/docs/api/javax/crypto/Cipher.html

also see http://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Electronic_codebook_.28ECB.29 for why ecb mode is often not a good idea (look at the penguin pictures).