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convert binary data to gzip file and decompress to a string c#

I am trying to decode binary data that represents a gzip file, I need to decompress the gzip so I can get the nbt (minecraft notation thing) string that is in the gzip, but I keep getting the following error at GZipStream.Read:
The archive entry was compressed using an unsupported compression method.
Does anyone have any idea on how to do this?
This is my code:
public static string Decompress(string input)
{
byte[] compressed = Convert.FromBase64String(input); //This is the binary data
byte[] decompressed = Decompress(compressed);
return Encoding.UTF8.GetString(decompressed);
}
private static byte[] Decompress(byte[] input)
{
using (var source = new MemoryStream(input))
{
byte[] lengthBytes = new byte[4];
source.Read(lengthBytes, 0, 4);
var length = BitConverter.ToInt32(lengthBytes, 0);
using (var decompressionStream = new GZipStream(source,
CompressionMode.Decompress))
{
var result = new byte[length];
decompressionStream.Read(result, 0, length); //Error
return result;
}
}
}

This should do it for you:
public static string Decompress(string value)
{
byte[] buffer = Convert.FromBase64String(value);
byte[] decompressed;
using (var inputStream = new MemoryStream(buffer))
{
using var outputStream = new MemoryStream();
using (var gzip = new GZipStream(inputStream, CompressionMode.Decompress, leaveOpen: true))
{
gzip.CopyTo(outputStream);
}
decompressed = outputStream.ToArray();
}
return Encoding.UTF8.GetString(decompressed);
}

Not able to Decompress the byte array of new secure QR code of Aadhar

I am trying to decompress the byte array using GZipStream but getting error of "Found invalid data while decoding."
// getting aadhaar sample qr code data from
// https://uidai.gov.in/images/resource/User_manulal_QR_Code_15032019.pdf
static void Main(string[] args)
{
string source = "6979414848205548481619299442879901900893978332594614407044767717485407280104077714658698163325401659212830920734233047578454701810567032015270223682917915825234703754712504887921309181789607809168884583848396456653007022479356336240198130363930881632367124738541517499494458139647378808680614169273221404741476596583953169248831376224396335169577064812987140578144885819479190173537644970232125142253963784979138011318798385442436099901621998283624816070080504830712594525760596934341576755626791590403636878139861665599383319429228364434183913197958738697001410493839281298692342829951566712530309758759364649701153639921979798429707566199261950037418171329283207372048014948669160666776198414040633384677104717697507521717586776709084200364956178863636105988867260929887577092955570407803783021397897341999914616790441029837229129746669225095633201097644321593502503404440714110515167034889128258965583435965030225845348564582051521348800742574442877087774194668983516629631073341202705453382780613775427336949283388084891654484225446940941660942440637784744293259916479841407088189462964489670231866481904237338494872813098890875845640034370370387108798950180220865436012752487216677041817312930119747601017807577565413977545693375480131324240696099879479436722576566447939593195590684591261809038023122178172006150499569185218838749337238281597037288924464009997530938336798176023597292328320965086990184531426188862965408313308973495924965144113396593829090645266653313774582036138982013368561474719154447134894466611560589758251829063226370300282175823479569847261439348404558251402273730865053482214589180028302043821438357583302818374143973997002745047526405755760407045006694423501337081780299815080324840337828812644300041900356816429114261098230198976752026002079876882796597235615015594486182057781476152918170746403157005216896239428521706033466061587608065036133153074432195952131368564234168005447770190345777024917629879639171161719929852078265309160759260989590618158889891835294735614366674503961584445497685736312628248483551986529867423016255476553691922054241686230968975229511700928171281549902682365302333677412951788839806869796040512235899311734337858684531156721416280114473368826463098485252394260075790386415875290922570568686439586036262465414002334117870088922801660529414759784318799843806130096998190881240404138869293309782335305296720666220243304175086358278211355789957998014801209332293458940463859106591986434520433810583569309224929264228263841477378949329312443958215939294432669464260216534074560882723006838459792812340253078330291135526952675203790833430237852831740601433198364243363569730205351077393441691141240055900819091229931605146865520183001810239708464322588389956036291760175558843819105418234580239610174323636606095262722940143706063698846499673285377621180570537788160304936809915237889489342387891057012783726694920184573202789672963922380028271124448024265644396686341508447830351380242127542393849410283830409594988503246799544444687606954881510597515686410993828907588979699141180160893062603338104857903239845856783130275935413569275439908789983311663211937449259444259898972766208";
BigInteger.TryParse(source, out BigInteger numBig);
byte[] bytes = numBig.ToByteArray();
string isoBytes2 = Decompress(bytes);
}
static string Decompress(byte[] gzBuffer)
{
using (MemoryStream ms = new MemoryStream())
{
int msgLength = BitConverter.ToInt32(gzBuffer, 0);
ms.Write(gzBuffer, 0, gzBuffer.Length);
byte[] buffer = new byte[msgLength];
ms.Position = 0;
int length;
using (GZipStream zip = new GZipStream(ms, CompressionMode.Decompress))
{
length = zip.Read(buffer, 0, buffer.Length);
}
var data = new byte[length];
Array.Copy(buffer, data, length);
return Encoding.UTF8.GetString(data);
}
}

In C#, we need to do reverse byte array after coverting byte array from biginteger and before decompression the byte array.
In Java, it not needed.

how to compress into ASCII readable text?

I need to store write compressed text into a QR Code, then scan and decompress it.
The source text are minified JSON strings:
{"ref":"WR0001","customsType":"GIFT","insuredValue":20000,"weight":500,"shippingMethod":"EMS","sender":{"notificationEmail":"asd#asd.com","phoneNumber":"+818023459877","address":{"name":"TestName","companyName":"TestCompanyName","address1":"Testaddress1","address2":"Testaddress2","city":"Testcity","postalCode":"111222","region":"Tokyo","countryIso2":"ES"}},"recipient":{"phoneNumber":"+81231231","address":{"name":"John","companyName":"Salchichon","address1":"myhome","address2":"somewhere","city":"somecity","region":"someregion","postalCode":"111","codiceFiscale":"232323","countryIso2":"IT"}},"items":[{"quantity":1,"price":1000,"customs":"Somecustoms1"},{"quantity":2,"price":1500,"customs":"Somecustoms2"}]}
Deflate seems to generate binary text like this
óMMÉ,I,ÉÌÏSÈÈ/QHÎÈLÎNÍS(K,È/*O,JŠ”%gèf§Vò [...truncated]
Is there a compression algorithm that will render base64 text? I need something I can store in a QR Code.
If I simply apply base64 encoding to the compressed bytes, I get a string that's larger than my source text!
public partial class Main : Form
{
public Main()
{
InitializeComponent();
this.KeyPress += new System.Windows.Forms.KeyPressEventHandler(this.Main_KeyPress);
}
List<char> _barcode = new List<char>(1000);
private void Main_KeyPress(object sender, KeyPressEventArgs e)
{
_barcode.Add(e.KeyChar);
// process barcode
if (e.KeyChar == 13 && _barcode.Count > 0)
{
string msg = new String(_barcode.ToArray());
MessageBox.Show(msg );
Console.WriteLine(msg);
//serializer
MemoryStream stream = new MemoryStream(Encoding.Default.GetBytes(msg));
byte[] compressedBytes;
compressedBytes = Compress(stream);
Console.WriteLine("compressed:" + Encoding.Default.GetString(compressedBytes));
Decompress(compressedBytes);
_barcode.Clear();
}
}
private static Stream Decompress(byte[] input)
{
var output = new MemoryStream();
using (var compressStream = new MemoryStream(input))
using (var decompressor = new DeflateStream(compressStream, CompressionMode.Decompress))
decompressor.CopyTo(output);
output.Position = 0;
Console.WriteLine("decompressed:" + Encoding.Default.GetString(output.ToArray()));
output.Position = 0;
return output;
}
private static byte[] Compress(Stream input)
{
using (var compressStream = new MemoryStream())
using (var compressor = new DeflateStream(compressStream, CompressionMode.Compress))
{
input.CopyTo(compressor);
compressor.Close();
return compressStream.ToArray();
}
}
}
}

If your data compresses 4:1 as you mention in a comment, then encoding with Base64 will only expand it by 33%, leaving you with 3:1 compression.
You could instead use Base85 encoding, choosing 85 printable characters. That will convert four bytes to five characters, instead of three bytes to four characters, as Base64 does.

ZLib C# inflate socket data

I'm trying to parse messages sent from a server that's compressed using zlib, but I'm not sure how to do so with C#'s implementation of async sockets. I'm using Microsoft's example for async client socket.
https://msdn.microsoft.com/en-us/library/bew39x2a(v=vs.110).aspx
I'm guessing the correct place to do the inflation is here:
private static void ReceiveCallback( IAsyncResult ar ) {
....
string bufferedString = Encoding.ASCII.GetString(state.buffer,0,bytesRead);
....
}
I've tried passing state.buffer as the input parameter to the following function along with bytesRead as the length, but this results in a System.IO.IOException: Corrupted data ReadInternal exception.
public static string UnZip(byte[] byteArray, int length)
{
//Prepare for decompress
System.IO.MemoryStream ms = new System.IO.MemoryStream(byteArray);
System.IO.Compression.GZipStream sr = new System.IO.Compression.GZipStream(ms,
System.IO.Compression.CompressionMode.Decompress);
//Reset variable to collect uncompressed result
byteArray = new byte[length];
//Decompress
int rByte = sr.Read(byteArray, 0, byteArray.Length);
//Transform byte[] unzip data to string
System.Text.StringBuilder sB = new System.Text.StringBuilder(rByte);
//Read the number of bytes GZipStream red and do not a for each bytes in
//resultByteArray;
for (int i = 0; i < rByte; i++)
{
sB.Append((char)byteArray[i]);
}
sr.Close();
ms.Close();
sr.Dispose();
ms.Dispose();
return sB.ToString();
}
How can I inflate the contents of state.buffer?

Decompress string in java from compressed string in C#

I was searching for the correct solution to decompress the string in java coming from c# code.I tried myself with lot of techniques in java like(gzip,inflatter etc.).but didn't get the solution.i got some error while trying to decompress the string in java from compressed string from c# code.
My C# code to compress the string is,
public static string CompressString(string text)
{
byte[] byteArray = Encoding.GetEncoding(1252).GetBytes(text);// Encoding.ASCII.GetBytes(text);
using (var ms = new MemoryStream())
{
// Compress the text
using (var ds = new DeflateStream(ms, CompressionMode.Compress))
{
ds.Write(byteArray, 0, byteArray.Length);
}
return Convert.ToBase64String(ms.ToArray());
}
}
And decompress the string in java using,
private static void compressAndDecompress(){
try {
// Encode a String into bytes
String string = "xxxxxxSAMPLECOMPRESSEDSTRINGxxxxxxxxxx";
// // Compress the bytes
byte[] decoded = Base64.decodeBase64(string.getBytes());
byte[] output = new byte[4096];
// Decompress the bytes
Inflater decompresser = new Inflater();
decompresser.setInput(decoded);
int resultLength = decompresser.inflate(output);
decompresser.end();
// Decode the bytes into a String
String outputString = new String(output, 0, resultLength, "UTF-8");
System.out.println(outputString);
} catch(java.io.UnsupportedEncodingException ex) {
ex.printStackTrace();
} catch (java.util.zip.DataFormatException ex) {
ex.printStackTrace();
}
}
I get this exception when running the above code:
java.util.zip.DataFormatException: incorrect header check
Kindly give me the sample code in java to decompress the string java.Thanks

My C# code to compress is
private string Compress(string text)
{
byte[] buffer = Encoding.UTF8.GetBytes(text);
MemoryStream ms = new MemoryStream();
using (GZipStream zip = new GZipStream(ms, CompressionMode.Compress, true))
{
zip.Write(buffer, 0, buffer.Length);
}
ms.Position = 0;
MemoryStream outStream = new MemoryStream();
byte[] compressed = new byte[ms.Length];
ms.Read(compressed, 0, compressed.Length);
byte[] gzBuffer = new byte[compressed.Length + 4];
System.Buffer.BlockCopy(compressed, 0, gzBuffer, 4, compressed.Length);
System.Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gzBuffer, 0, 4);
return Convert.ToBase64String(gzBuffer);
}
Java code to decompress the text is
private String Decompress(String compressedText)
{
byte[] compressed = compressedText.getBytes("UTF8");
compressed = org.apache.commons.codec.binary.Base64.decodeBase64(compressed);
byte[] buffer=new byte[compressed.length-4];
buffer = copyForDecompression(compressed,buffer, 4, 0);
final int BUFFER_SIZE = 32;
ByteArrayInputStream is = new ByteArrayInputStream(buffer);
GZIPInputStream gis = new GZIPInputStream(is, BUFFER_SIZE);
StringBuilder string = new StringBuilder();
byte[] data = new byte[BUFFER_SIZE];
int bytesRead;
while ((bytesRead = gis.read(data)) != -1)
{
string.append(new String(data, 0, bytesRead));
}
gis.close();
is.close();
return string.toString();
}
private byte[] copyForDecompression(byte[] b1,byte[] b2,int srcoffset,int dstoffset)
{
for(int i=0;i<b2.length && i<b1.length;i++)
{
b2[i]=b1[i+4];
}
return b2;
}
This code works perfectly fine for me.

Had exactly the same issue. Could solve it via
byte[] compressed = Base64Utils.decodeFromString("mybase64encodedandwithc#zippedcrap");
Inflater decompresser = new Inflater(true);
decompresser.setInput(compressed);
byte[] result = new byte[4096];
decompresser.inflate(result);
decompresser.end();
System.out.printf(new String(result));
The magic happens with the boolen parameter on instantiating the Inflator
BW Hubert

For beloved googlers,
As #dbw mentioned,
according to post How to decompress stream deflated with java.util.zip.Deflater in .NET?,
java.util.zip.deflater equivalent in c# the default deflater used in C#
is not having any java equivalent that's why users prefer Gzip, Ziplib
or some other zip techniques.
a relatively simple method would be using GZip.
And for the accepted answer, one problem is that in this method you should append the data size to the compressed string yourself, and more importantly as per my own experience in our production app, It is buggy when the string reaches ~2000 chars!
the bug is in the System.io.Compression.GZipStream
any way using SharpZipLib in c# the problem goes away and everything would be as simple as following snippets:
JAVA:
import android.util.Base64;
import com.google.android.gms.common.util.IOUtils;
import org.jetbrains.annotations.Nullable;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
public class CompressionHelper {
#Nullable
public static String compress(#Nullable String data) {
if(data == null || data.length() == 0)
return null;
try {
// Create an output stream, and a gzip stream to wrap over.
ByteArrayOutputStream bos = new ByteArrayOutputStream(data.length());
GZIPOutputStream gzip = new GZIPOutputStream(bos);
// Compress the input string
gzip.write(data.getBytes());
gzip.close();
byte[] compressed;
// Convert to base64
compressed = Base64.encode(bos.toByteArray(),Base64.NO_WRAP);
bos.close();
// return the newly created string
return new String(compressed);
} catch(IOException e) {
return null;
}
}
#Nullable
public static String decompress(#Nullable String compressedText) {
if(compressedText == null || compressedText.length() == 0)
return null;
try {
// get the bytes for the compressed string
byte[] compressed = compressedText.getBytes("UTF-8");
// convert the bytes from base64 to normal string
compressed = Base64.decode(compressed, Base64.NO_WRAP);
ByteArrayInputStream bis = new ByteArrayInputStream(compressed);
GZIPInputStream gis = new GZIPInputStream(bis);
byte[] bytes = IOUtils.toByteArray(gis);
return new String(bytes, "UTF-8");
}catch (IOException e){
e.printStackTrace();
}
return null;
}
}
and c#:
using ICSharpCode.SharpZipLib.GZip; //PM> Install-Package SharpZipLib
using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace GeneralTools
{
public static class CompressionTools
{
public static string CompressString(string text)
{
if (string.IsNullOrEmpty(text))
return null;
byte[] buffer = Encoding.UTF8.GetBytes(text);
using (var compressedStream = new MemoryStream())
{
GZip.Compress(new MemoryStream(buffer), compressedStream, false);
byte[] compressedData = compressedStream.ToArray();
return Convert.ToBase64String(compressedData);
}
}
public static string DecompressString(string compressedText)
{
if (string.IsNullOrEmpty(compressedText))
return null;
byte[] gZipBuffer = Convert.FromBase64String(compressedText);
using (var memoryStream = new MemoryStream())
{
using (var compressedStream = new MemoryStream(gZipBuffer))
{
var decompressedStream = new MemoryStream();
GZip.Decompress(compressedStream, decompressedStream, false);
return Encoding.UTF8.GetString(decompressedStream.ToArray()).Trim();
}
}
}
}
}
you may also find the codes here

If anyone still interested, here's my full solution with outputstream to handle unknown string size. Using C# DeflateStream and Java Inflater (based on Hubert Ströbitzer answer).
C# Compression:
string CompressString(string raw)
{
byte[] uncompressedData = Encoding.UTF8.GetBytes(raw);
MemoryStream output = new MemoryStream();
using (DeflateStream dStream = new DeflateStream(output, CompressionLevel.Optimal))
{
dStream.Write(uncompressedData, 0, uncompressedData.Length);
}
string compressedString = Convert.ToBase64String(output.ToArray());
return compressedString;
}
Java decompress:
String decompressString(String compressedString) {
byte[] compressed = Base64Utils.decodeFromString(compressedString);
Inflater inflater = new Inflater(true);
inflater.setInput(compressed);
//Using output stream to handle unknown size of decompressed string
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
try {
while(!inflater.finished()){
int count = inflater.inflate(buffer);
outputStream.write(buffer, 0, count);
}
inflater.end();
outputStream.close();
} catch (DataFormatException e) {
//Handle DataFormatException
} catch (IOException e) {
//Handle IOException
}
return outputStream.toString();
}