java - Using streams to decrypt and unzip to limit memory usage? -

-

I have a very large zip file, 2.5 GB, which is encrypted. I can not decrypt the whole file in memory And do not want to open them there for production. So I'm trying to use the currents to limit the amount of memory used.

I have tilted the following to do this (error handling and stream ending has been left for clarity): 

  SECRETARY SPECEC keySPEC = new secret of SPEC (mike) "AES"); Cipher cipher = cipher Get Instances ("AES / CBC / PKCS5 Padding"); FileInputStream fis = New FileInputStream (new file (pathToEncryptedFile)); Cipherinputstream cis = new cipher inputstream (fis, cipher); ZipInputStream zis = new ZIPInproststream (new BufferedInputStream (cis)); Zipantries = null; While ((ze = zis.getNextEntry ()) = null) {string filename = ze.getName (); System.out.println ("Enter the zip entry:" + file name); }

This works for approximately 50% of my files, even though they are all zipped and encrypted in the same way. Exception will be found in the loop () for the undefined portion: 

  java.util.zip.ZipException: Unknown format (EXTSIG = f23f1090) java.util.zip.ZipInputStream on .read andVerifyDataDescriptor (ZipInputStream .java: 196) ...

If I decrypt the whole file in a byte buffer and write it on disk, then use the zip input page on the file, it's all about Works for my exam files.

It seems that there is some problem in using extra padding streams at the end of the encrypted file, but I thought "PKCS 5 padding" specification will keep it in mind.

Thanks

decrypted file Use the ZIP Intestream on Without Reading it in memory If it fails, your file can not be read anyway, and it needs to be recreated (maybe That this is a little non-standard). If it succeeds, then check the results of the decryption stream (before this pinip input) and check the binary difference.


Comments

Post a Comment

Popular posts from this blog

import - Python ImportError: No module named wmi -

-
I followed the instructions for downloading WMI for Python When I try to run the code for C.Win32_Service (StartMode = "Auto", state = "Stopped") import wmi c = wmi.WMI (): if Raw_input ("restart% s?"% S.Caption) .upper () == "Y": s.StartService () I got the error traceback (most recent call end): file ". \", Line 1, edit: I am using Python 2.7.6 EDIT2: I am running 64-bit Windows 2008 R2, and I've downloaded WMI-1.4.9.zip (md5). I removed the content and put it in D: Python \ Tools \ Scripts I executed dragon setup.py.install I said D : \ Python \ tools \ scripts to% PATH% and when I execute the code for C.Win32_Service (StartMode = "Auto", state = "Stopped") import wmi c = Wmi.WMI (): If raw_input ("Restart% s?"% S. Caption). () == "Y": s.StartService () error me Gets traceback (most recent call final): File ". See \", line 1, & lt; Modu...
Read more

Editing Python Class in Shell and SQLAlchemy -

-
I am working on the terminal on a shell script after this tutorial SQLAlchemy tutorial. I need to type gt; & Gt; & Gt; Sqlalchemy import column, integer, string & gt; & Gt; & Gt; Class user (base): __tablename__ = 'users' id = column (integer, primary_key = true) name = column (string) absolute name = column (string) password = column (string) def __repr __ (self): return "& lt ; User (name = '% s', absolute name = '% s', password = '% s') & gt; "% (Self.name, self.fullname, self.password) After the problem I have typed the password = column (string) I hit twice and changed .... >> I then took everything back but then an error was thrown because the class already exists ... I am not completely sure how to fix it. How do I open that slip in the shell script and edit it (Add DF to DRR) The error thrown below: / user / giripeters / TFSQLLX / Lib / python2.7 / site-packages / sqlalchemy / ext / decla...
Read more

lua - HowTo create a fuel bar -

-
I would like to create a fuel bar (empty with full tank). When the user touches the screen, the fuel once Dairejh these is my code: lifeBar = display.newImage ( "fuel_bar1.png") lifeBar.anchorX = 0 lifeboats. ======================== Lifetime Y = 37 screens Group: The Insert function (called Laifbar) However, I fuel Kansmoshn (equivalent to "pressed" variable to reduce the fuel tank "true") Have used. When pressed == is true, it means that the user is touching the screen: processed (fuel) processed () if life & gt; 0 and pressed == true remains = life - life 1 Life = life =. Wide-1 remains Value.text = string.format ("% d", life) End of this This function is active as the entrance event: runtime: addEventListener ( "Antrfrem" fuel Snsadna) it is very well, but my question is: pressed variable each time 5 seconds (once = = True) How is it possible to reduce the vitality width? I tried to add it to my touch even...
Read more