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Posted 20 Nov 2000


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Compression and decompression using the Crypto++ library

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16 Apr 2001CPOL
Using the Crypto++ library to compress and decompress data


The Crypto++ library is a freeware library of cryptographic schemes, written by Wei Dai. However the library also contains other useful classes which are not immediately apparent when you use the library. Two of these are the Gzip and Gunzip classes which can be used to compress and decompress (zip and unzip) data.


Compressing your data could not be simpler. Say you had data pData that was of size dwLen that you wished to compress.

#include <gzip.h>

Gzip zipper(1);    // 1 is fast, 9 is slow


  byte* pCompressed = new byte[zipper.MaxRetrieveable()];

pCompressed now contains the compressed data.


You may not be surprised to know that decompression is just as easy. (dwLen is now the length of our compressed data)

Gunzip unzipper;


  byte* pData = new byte[unzipper.MaxRetrieveable()];

pData now contains the uncompressed data.


Thanks to Wei Dai for his permission to write this article in what is hoped to be a series of articles on the use of his Crypto++ library.

Latest versions

The latest versions of the Crypto++ library can be found here.


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Shaun Wilde
Employed (other) Purplebricks
Australia Australia
All articles are supplied as-is, as a howto on a particular task that worked for me in the past. None of the articles are supposed to be out-of-the-box freeware controls and nor should they be treated as such. Caveat emptor.

Now living and working in Australia, trying to be involved in the local .NET and Agile communities when I can.

I spend a good chunk of my spare time building OpenCover and maintaining PartCover both of which are Code Coverage utilities for .NET.

Comments and Discussions

Questionpassword protected archive? Pin
Matthias Blum15-Jan-09 13:23
MemberMatthias Blum15-Jan-09 13:23 
AnswerRe: password protected archive? Pin
Shaun Wilde16-Jan-09 0:06
MemberShaun Wilde16-Jan-09 0:06 
GeneralCompressing and Decompressing Data using C++ Pin
jassshan24-Nov-08 21:39
Memberjassshan24-Nov-08 21:39 
GeneralGzip a set of files Pin
sheyliger7-Jul-08 3:21
Membersheyliger7-Jul-08 3:21 
GeneralRe: Gzip a set of files Pin
Shaun Wilde7-Jul-08 8:35
MemberShaun Wilde7-Jul-08 8:35 
GeneralWell I've added header but it doesn't work Pin
Noagene15-Aug-07 21:36
MemberNoagene15-Aug-07 21:36 
GeneralRe: Well I've added header but it doesn't work Pin
Shaun Wilde18-Aug-07 23:28
MemberShaun Wilde18-Aug-07 23:28 
GeneralRe: Well I've added header but it doesn't work Pin
Noagene19-Aug-07 13:38
MemberNoagene19-Aug-07 13:38 
GeneralError code has been changed.. Pin
Noagene19-Aug-07 18:55
MemberNoagene19-Aug-07 18:55 
AnswerRe: Error code has been changed.. Pin
butuzov_Ilya6-Sep-07 22:27
Memberbutuzov_Ilya6-Sep-07 22:27 
GeneralClose() is No Longer Available... Pin
Jeffrey Walton27-May-07 15:21
MemberJeffrey Walton27-May-07 15:21 
GeneralRe: Close() is No Longer Available... Pin
Shaun Wilde28-May-07 10:04
MemberShaun Wilde28-May-07 10:04 
GeneralRe: Close() is No Longer Available... Pin
Jeffrey Walton28-May-07 11:03
MemberJeffrey Walton28-May-07 11:03 
GeneralRe: Close() is No Longer Available... Pin
Shaun Wilde29-May-07 19:55
MemberShaun Wilde29-May-07 19:55 
GeneralRe: Close() is No Longer Available... Pin
Jeffrey Walton28-May-07 11:08
MemberJeffrey Walton28-May-07 11:08 
GeneralRe: Close() is No Longer Available... Pin
Shaun Wilde29-May-07 19:56
MemberShaun Wilde29-May-07 19:56 
GeneralCrypto++ Integration Article Pin
Jeffrey Walton8-Dec-06 18:28
MemberJeffrey Walton8-Dec-06 18:28 
GeneralGzip work verry greatly! Pin
dungbkhn28-Jun-05 17:50
Memberdungbkhn28-Jun-05 17:50 
GeneralGot a wrong result! Pin
JerryCheng11-Nov-03 22:44
MemberJerryCheng11-Nov-03 22:44 
GeneralRe: Got a wrong result! Pin
Shaun Wilde12-Nov-03 8:13
MemberShaun Wilde12-Nov-03 8:13 
GeneralRe: Got a wrong result! Pin
JerryCheng13-Nov-03 16:59
MemberJerryCheng13-Nov-03 16:59 
GeneralRe: Got a wrong result! Pin
Shaun Wilde14-Nov-03 4:43
MemberShaun Wilde14-Nov-03 4:43 
Questionencryption of Pin
xxhimanshu11-Nov-03 20:40
Memberxxhimanshu11-Nov-03 20:40 
AnswerRe: encryption of Pin
Shaun Wilde12-Nov-03 8:17
MemberShaun Wilde12-Nov-03 8:17 
Generalzipping Pin
Anonymous1-Jun-03 8:24
MemberAnonymous1-Jun-03 8:24 

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