Calculation of hash value of a matrix - cryptography

As part of my final year project, I am testing the Bouncycastle library on SHA-3.
I have found the source code to calculate the hash value of a string:
String input = "hello" ;
SHA3.DigestSHA3 digestSHA3 = new SHA3.Digest256();
byte[] digest = digestSHA3.digest(input.getBytes());
System.out.println("SHA3-256 = " + Hex.toHexString(digest));
but i want to calculate the hash value of a matrix, Anyone who can help me with this?

You need to uniquely convert matrix to byte array. One of the possible solutions:
private static byte[] intToBytes(int value) {
return new byte[] {
(byte)(value >>> 24),
(byte)(value >>> 16),
(byte)(value >>> 8),
(byte)value
};
}
public static void main(String[] args) throws Exception {
int[][] matrix = new int[3][5];
SHA3.DigestSHA3 sha3 = new SHA3.Digest256();
int height = matrix.length;
int width = matrix[0].length;
sha3.update(intToBytes(height)); // add height of the matrix
sha3.update(intToBytes(width)); // add width
for (int i = 0; i < height; i++) {
for (int j = 0; j < width; j++) {
sha3.update(intToBytes(matrix[i][j])); // add all values
}
}
byte[] digest = digest.digest();
}

Related

Why doesn't my number sequence print from the 2d arraylist correctly?

I cannot get the loop to work in the buildDimArray method to store the number combinations "11+11", "11+12", "11+21", "11+22", "12+11", "12+12", "12+21", "12+22", "21+11", "21+12", "21+21", "21+22", "22+11", "22+12", "22+21", and "22+22" into the 2d arraylist with each expression going into one column of the index dimBase-1 row. The loop may work for other people, but for some reason mine isn't functioning correctly. The JVM sees the if dimBase==1 condition, but refuses to check the other conditions. The "WTF" not being printed as a result from the buildDimArray method. If dimBase=1, it prints successfully, but doesn't for the other integers. The dimBase==3 condition needs a loop eventually. The "WTF" is for illustrative purposes. I could get away with a 1d arraylist, but in the future I will likely need the 2d arraylist once the program is completed.
package jordanNumberApp;
import java.util.Scanner;
import java.util.ArrayList;
/*
* Dev Wills
* Purpose: This code contains some methods that aren't developed. This program is supposed to
* store all possible number combinations from numbers 1-dimBase for the math expression
* "##+##" into a 2d arraylist at index row dimBase-1 and the columns storing the
* individual combinations. After storing the values in the arraylist, the print method
* pours the contents in order from the arraylist as string values.
*/
public class JordanNumberSystem {
// a-d are digits, assembled as a math expression, stored in outcomeOutput, outcomeAnswer
public static int dimBase, outcomeAnswer, a, b, c, d;
public static String inputOutcome, outcomeOutput;
public static final int NUM_OF_DIMENSIONS = 9; //Eventually # combinations go up to 9
public static ArrayList<ArrayList<String>> dimBaseArray;
public static Scanner keyboard;
/*
* Constructor for JordanNumber System
* accepts no parameters
*/
public JordanNumberSystem() // Defunct constructor
{
// Declare and Initialize public variables
this.dimBase = dimBase;
this.outcomeOutput = outcomeOutput;
this.outcomeAnswer = outcomeAnswer;
}
// Set all values of variable values
public static void setAllValues()
{
// Initialize
dimBase = 1;
outcomeAnswer = 22; // variables not used for now
outcomeOutput = "1"; // variables not used for now
//a = 1;
//b = 1;
//c = 1;
//d = 1;
dimBaseArray = new ArrayList<ArrayList<String>>();
keyboard = new Scanner(System.in);
}
public static void buildDimArray(int dim)
{
dimBase = dim;
try
{
//create first row
dimBaseArray.add(dimBase-1, new ArrayList<String>());
if( dimBase == 1)
{
a = b = c = d = dimBase ;
dimBaseArray.get(0).add(a+""+b+"+"+c+""+d);
System.out.println("WTF"); // SHOWS
}
else if (dimBase == 2)
{ // dim = 2
a = b = c = d = 1 ;
System.out.println("WTF"); // doesn't show
// dimBaseArray.get(dimBase-1).add(a+""+b+"+"+c+""+d);
for( int i = 1 ; i <= dim ; i++)
a=i;
for( int j = 1 ; j <= dim ; j++)
b=j;
for( int k = 1 ; k <= dim ; k++)
c=k;
for( int l = 1 ; l <= dim ; l++)
{
d=l;
dimBaseArray.get(dim-1).add(a+""+b+"+"+c+""+d);
}
}
else if (dimBase == 3)
{
a = b = c = d = dimBase;
dimBaseArray.get(2).add(a+""+b+"+"+c+""+d);
System.out.println("WTF");
}
}catch (IndexOutOfBoundsException e)
{
System.out.println(e.getMessage());
}
}
public static void printArray(int num) // Prints the contents of the array
{ // Fixing the printing method
try
{
int i = num-1;
for( String string : dimBaseArray.get(i))
{
System.out.println(string);
System.out.println("");
}
} catch (IndexOutOfBoundsException e)
{
System.out.println(e.getMessage());
}
}
public static void main(String[] args) throws java.lang.IndexOutOfBoundsException
{
setAllValues(); // sets the initial a,b,c,d values and dimBase, initializes 2d arraylist
// Get the Dimension Base number
System.out.println("Enter Dimension Base Number. Input an integer: ");
int dimBaseInput = keyboard.nextInt(); // Receives integer
dimBase = dimBaseInput;
if( dimBase != 1 && dimBase != 2 && dimBase != 3)
{// Error checking
System.out.println("invalid Dimension Base Number should be 1 or 2 ");
System.exit(1);
}
// Build the arraylist, print, clear, exit
buildDimArray(dimBase);
printArray(dimBase);
dimBaseArray.clear();
System.exit(1);
}
}// End of class

Store cell values to Object

I'm currently new to TestNG using java. I'm trying to read the values from an excel using poi apache 4.0
public static void read2dRowExcelFile2(String filePath) throws IOException {
try {
FileInputStream fis = new FileInputStream(new File(filePath));
HSSFWorkbook wb = new HSSFWorkbook(fis);
HSSFSheet sheet = wb.getSheet("PerLocation");
Object[][] tableArr = new String[sheet.getLastRowNum() + 1][];
int arrNo1 = 0;
for (int i = 1; i <= sheet.getLastRowNum(); i++) {
Row row = sheet.getRow(i);
int arrNo2 = 0;
for (int j = 0; j < row.getLastCellNum(); j++) {
String cellValue = row.getCell(j).getStringCellValue();
System.out.println(acellValue);
//tableArr[arrNo1][arrNo2] = cellValue;
System.out.println("test");
arrNo2++;
}
arrNo1++;
}
wb.close();
} catch (Exception e) {
e.printStackTrace();
}
}
Code above displays the values on the console. My goal is to store those values to an Object. Something like [{London, Blue},{Tokyo,Yellow},{Manila,Red}] so I can pass them to a dataProvider
If I run the code above, it displays :
London
BLue
Tokyo
Yellow
Manila
Red
But If i uncomment this line :
//tableArr[arrNo1][arrNo2] = cellValue;
The output is only :
London
03-08-19 : After I enabled stacktrace, it says : java.lang.NullPointerException
which pertains to this code :
tableArr[arrNo1][arrNo2] = cellValue;
From your code,
Object[][] tableArr = new String[sheet.getLastRowNum() + 1][];
At the time of initialization of array, your are setting size of first dimension but not the second . You need to initialize array for second dimension before you access it.
Refer below example:
public static void main(String[] args) {
//read rows size
int numOfRows = 3;
String[][] tableArr = new String[numOfRows][];
for (int row = 0; row <3; row++) {
//read columns size
int numOfColsInRow = 3;
tableArr[row]=new String[numOfColsInRow];
for (int col = 0; col < 3; col++) {
String cellValue = "cell-" + row+""+col;//read cell value
tableArr[row][col] = cellValue;
}
}
for(String[] row: tableArr) {
System.out.println(Arrays.toString(row));
}
}
Running above code with generate expected output:
[cell-00, cell-01, cell-02]
[cell-10, cell-11, cell-12]
[cell-20, cell-21, cell-22]
To reproduce your problem you can try commenting line which initialize array for second dimension in the code and you will see Exception in thread "main" java.lang.NullPointerException
.
//tableArr[row]=new String[numOfColsInRow];
To avoid all such issues you also can check if any exiting TestNG data-provider extension satisfies your need.

Slow image processing of images from filesystem as compared to the webcam

I was able to follow the csharp-sample-apps from the github repo for Affectiva. I ran the demo using my webcam and the processing and performance was great.I am not getting the same processing speed from the PhotoDetector when I try to run it over images in filesystem. Any help or improvement would be appreciated.
namespace Logical.EmocaoFace
{
public class AnaliseEmocao : Affdex.ImageListener, Affdex.ProcessStatusListener
{
private Bitmap img { get; set; }
private Dictionary<int, Affdex.Face> faces { get; set; }
private Affdex.Detector detector { get; set; }
private ReaderWriterLock rwLock { get; set; }
public void processaEmocaoImagem()
{
for (int i = 0; i < resultado.count; i++){
RetornaEmocaoFace();
if (faceAffdex != null)
{
}
}
}
public void RetornaEmocaoFace(string caminhoImagem)
{
Affdex.Detector detector = new Affdex.PhotoDetector(1, Affdex.FaceDetectorMode.LARGE_FACES);
detector.setImageListener(this);
detector.setProcessStatusListener(this);
if (detector != null)
{
//ProcessVideo videoForm = new ProcessVideo(detector);
detector.setClassifierPath(#"D:\Desenvolvimento\Componentes\Afectiva\data");
detector.setDetectAllEmotions(true);
detector.setDetectAllExpressions(false);
detector.setDetectAllEmojis(false);
detector.setDetectAllAppearances(false);
detector.start();
((Affdex.PhotoDetector)detector).process(LoadFrameFromFile(caminhoImagem));
detector.stop();
}
}
static Affdex.Frame LoadFrameFromFile(string fileName)
{
Bitmap bitmap = new Bitmap(fileName);
// Lock the bitmap's bits.
Rectangle rect = new Rectangle(0, 0, bitmap.Width, bitmap.Height);
BitmapData bmpData = bitmap.LockBits(rect, ImageLockMode.ReadWrite, bitmap.PixelFormat);
// Get the address of the first line.
IntPtr ptr = bmpData.Scan0;
// Declare an array to hold the bytes of the bitmap.
int numBytes = bitmap.Width * bitmap.Height * 3;
byte[] rgbValues = new byte[numBytes];
int data_x = 0;
int ptr_x = 0;
int row_bytes = bitmap.Width * 3;
// The bitmap requires bitmap data to be byte aligned.
// http://stackoverflow.com/questions/20743134/converting-opencv-image-to-gdi-bitmap-doesnt-work-depends-on-image-size
for (int y = 0; y < bitmap.Height; y++)
{
Marshal.Copy(ptr + ptr_x, rgbValues, data_x, row_bytes);//(pixels, data_x, ptr + ptr_x, row_bytes);
data_x += row_bytes;
ptr_x += bmpData.Stride;
}
bitmap.UnlockBits(bmpData);
//Affdex.Frame retorno = new Affdex.Frame(bitmap.Width, bitmap.Height, rgbValues, Affdex.Frame.COLOR_FORMAT.BGR);
//bitmap.Dispose();
//return retorno;
return new Affdex.Frame(bitmap.Width, bitmap.Height, rgbValues, Affdex.Frame.COLOR_FORMAT.BGR);
}
public void onImageCapture(Affdex.Frame frame)
{
frame.Dispose();
}
public void onImageResults(Dictionary<int, Affdex.Face> faces, Affdex.Frame frame)
{
byte[] pixels = frame.getBGRByteArray();
this.img = new Bitmap(frame.getWidth(), frame.getHeight(), PixelFormat.Format24bppRgb);
var bounds = new Rectangle(0, 0, frame.getWidth(), frame.getHeight());
BitmapData bmpData = img.LockBits(bounds, ImageLockMode.WriteOnly, img.PixelFormat);
IntPtr ptr = bmpData.Scan0;
int data_x = 0;
int ptr_x = 0;
int row_bytes = frame.getWidth() * 3;
// The bitmap requires bitmap data to be byte aligned.
// http://stackoverflow.com/questions/20743134/converting-opencv-image-to-gdi-bitmap-doesnt-work-depends-on-image-size
for (int y = 0; y < frame.getHeight(); y++)
{
Marshal.Copy(pixels, data_x, ptr + ptr_x, row_bytes);
data_x += row_bytes;
ptr_x += bmpData.Stride;
}
img.UnlockBits(bmpData);
this.faces = faces;
frame.Dispose();
}
public void onProcessingException(Affdex.AffdexException A_0)
{
throw new NotImplementedException("Encountered an exception while processing " + A_0.ToString());
}
public void onProcessingFinished()
{
string idArquivo = CodEspaco + "," + System.Guid.NewGuid().ToString();
for(int i = 0; i < faces.Count; i++)
{
}
}
}
public static class GraphicsExtensions
{
public static void DrawCircle(this Graphics g, Pen pen,
float centerX, float centerY, float radius)
{
g.DrawEllipse(pen, centerX - radius, centerY - radius,
radius + radius, radius + radius);
}
}
}
Found the answer to my own question:
Using PhotoDetector is not ideal in this case since it is expensive to use the Face Detector configuration on subsequent frame calls.
The best option to improve the performance would be to use an instance of the FrameDetector Class.
Here is a getting started guide to analyze-frames.

Zedgraph - Change X-Axis from points to frequency

i have a working program where i can add an array to a Zedgraph and show this in a form.
Now i only want to change the display of the x-axis from points (0..400) to frequency (9e3..6e9 Hz).
Here are my currently working functions:
public void AddGraph(double[] Values, string LegendName)
{
int i = 0;
PointPairList list = new PointPairList();
for (i = 0; i < Values.Length; i++)
{
list.Add(i, Values[i]);
}
if (i > MaxXAxis)
MaxXAxis = i;
SList.Add(list);
SListColor.Add(Color.Black);
}
SListName.Add(LegendName);
}
public void ShowDiagram(string Title, string XAxisName, string YAxisName,
int Timeout_ms)
{
ZedGraph.ZedGraphControl zgc = new ZedGraphControl();
GraphPane myPane = zgc.GraphPane;
LineItem myCurve = null;
// Set the titles and axis labels
myPane.Title.Text = Title;
myPane.XAxis.Title.Text = XAxisName;
myPane.YAxis.Title.Text = YAxisName;
for (int i = 0; i < SList.Count(); i++)
{
myCurve = myPane.AddCurve(SListName[i], SList[i], SListColor[i],
SymbolType.None);
myCurve.Line.Width = 2;
}
// Add gridlines to the plot, and make them gray
myPane.XAxis.MinorGrid.IsVisible = true;
myPane.YAxis.MinorGrid.IsVisible = true;
myPane.XAxis.MinorGrid.Color = Color.LightGray;
myPane.YAxis.MinorGrid.Color = Color.LightGray;
myPane.XAxis.MinorGrid.DashOff = 0;
myPane.YAxis.MinorGrid.DashOff = 0;
myPane.XAxis.MajorGrid.IsVisible = true;
myPane.YAxis.MajorGrid.IsVisible = true;
myPane.XAxis.MajorGrid.Color = Color.Gray;
myPane.YAxis.MajorGrid.Color = Color.Gray;
myPane.XAxis.MajorGrid.DashOff = 0;
myPane.YAxis.MajorGrid.DashOff = 0;
// Move Legend to bottom
myPane.Legend.Position = LegendPos.Bottom;
zgc.AxisChange();
myPane.XAxis.Scale.Max = MaxXAxis;
zgc.Location = new Point(0, 0);
zgc.Size = new Size(panel_diagramm.ClientRectangle.Width, panel_diagramm.ClientRectangle.Height);
panel_diagramm.Controls.Add(zgc);
}
How can i change the above two functions that they display the frequency in the x-axis?
I already tried to change the AddGraph-function to pass the needed parameters and to calculate the list to have the correct values. But what then...?
public void AddGraph_Frequency(int **Points**, double **StartFrequency**,
double **StopFrequency**, double[] Values, string GraphColor, string LegendName)
{
...
double frequency = StartFrequency; //der erste Punkt
double Intervall = (StopFrequency - StartFrequency) / Points;
for (i = 0; i < Points; i++)
{
list.Add(frequency, Values[i]);
frequency = frequency + Intervall;
}
....
}
Thanks for any help
best regards
Solved.
Missing was:
myPane.XAxis.Scale.Max = Stopfrequency;
myPane.XAxis.Scale.Min = Startfrequency;

iTextSharp Twisting CCITTFaxDecode extracted data with GetDrawingImage()

On certain images, when I call:
PdfImageObject pimg = new PdfImageObject(stream);
Image bmp = pimg.GetDrawingImage();
The Image that is returned is twisted. I've seen this before and it usually has to do with byte alignment but I'm not sure how to get around this.
The /DecodeParms for this object are /EndOfLine true /K 0 /Columns 3300.
I have tried using the GetStreamBytesRaw() with BitMiracle.LibTiff and with it I can get the data formatted properly although the image is rotated. I'd prefer for GetDrawingImage() to decode the data properly if possible, assuming that is the problem.
I could provide the PDF via email if requested.
Thanks,
Darren
For anyone else that runs across this scenario here is my solution. The key to this puzzle was understanding that /K 0 is G3, /K -1 (or anything less than 0) is G4 /K 1 (or anything greater than 0) is G3-2D.
The twisting happens when you try to make G3 compressed data fit into a G4 image which it appears that is what iTextSharp may be doing. I know it definitely does not work with how I have iTextSharp implemented in my project. I confess that I cannot decipher all the decoding stuff that iTextSharp is doing so it could be something I'm missing too.
EndOfLine didn't have any part in this puzzle but I still think putting line feeds in binary data is a strange practice.
99% of this code came from BitMiracle.LibTiff.Net - Thank you.
int nK = 0;// Default to 0 like the PDF Spec
PdfObject oDecodeParms = stream.Get(PdfName.DECODEPARMS);
if (oDecodeParms is PdfDictionary)
{
PdfObject oK0 = ((PdfDictionary)oDecodeParms).Get(PdfName.K);
if (oK0 != null)
nK = ((PdfNumber)oK0).IntValue;
}
using (MemoryStream ms = new MemoryStream())
{
using (Tiff tiff = Tiff.ClientOpen("custom", "w", ms, new TiffStream()))
{
tiff.SetField(TiffTag.IMAGEWIDTH, width);
tiff.SetField(TiffTag.IMAGELENGTH, height);
if (nK == 0 || nK > 0) // 0 = Group 3, > 0 = Group 3 2D
tiff.SetField(TiffTag.COMPRESSION, Compression.CCITTFAX3);
else if (nK < 0) // < 0 = Group 4
tiff.SetField(TiffTag.COMPRESSION, Compression.CCITTFAX4);
tiff.SetField(TiffTag.BITSPERSAMPLE, bpc);
tiff.SetField(TiffTag.SAMPLESPERPIXEL, 1);
tiff.WriteRawStrip(0, rawBytes, rawBytes.Length); //saving the tiff file using the raw bytes retrieved from the PDF.
tiff.Close();
}
TiffStreamForBytes byteStream = new TiffStreamForBytes(ms.ToArray());
using (Tiff input = Tiff.ClientOpen("bytes", "r", null, byteStream))
{
int stride = input.ScanlineSize();
Bitmap result = new Bitmap(width, height, pixelFormat);
ColorPalette palette = result.Palette;
palette.Entries[0] = System.Drawing.Color.White;
palette.Entries[1] = System.Drawing.Color.Black;
result.Palette = palette;
for (int i = 0; i < height; i++)
{
Rectangle imgRect = new Rectangle(0, i, width, 1);
BitmapData imgData = result.LockBits(imgRect, ImageLockMode.WriteOnly, pixelFormat);
byte[] buffer = new byte[stride];
input.ReadScanline(buffer, i);
System.Runtime.InteropServices.Marshal.Copy(buffer, 0, imgData.Scan0, buffer.Length);
result.UnlockBits(imgData);
}
}
}
/// <summary>
/// Custom read-only stream for byte buffer that can be used
/// with Tiff.ClientOpen method.
/// </summary>
public class TiffStreamForBytes : TiffStream
{
private byte[] m_bytes;
private int m_position;
public TiffStreamForBytes(byte[] bytes)
{
m_bytes = bytes;
m_position = 0;
}
public override int Read(object clientData, byte[] buffer, int offset, int count)
{
if ((m_position + count) > m_bytes.Length)
return -1;
Buffer.BlockCopy(m_bytes, m_position, buffer, offset, count);
m_position += count;
return count;
}
public override void Write(object clientData, byte[] buffer, int offset, int count)
{
throw new InvalidOperationException("This stream is read-only");
}
public override long Seek(object clientData, long offset, SeekOrigin origin)
{
switch (origin)
{
case SeekOrigin.Begin:
if (offset > m_bytes.Length)
return -1;
m_position = (int)offset;
return m_position;
case SeekOrigin.Current:
if ((offset + m_position) > m_bytes.Length)
return -1;
m_position += (int)offset;
return m_position;
case SeekOrigin.End:
if ((m_bytes.Length - offset) < 0)
return -1;
m_position = (int)(m_bytes.Length - offset);
return m_position;
}
return -1;
}
public override void Close(object clientData)
{
// nothing to do
return;
}
public override long Size(object clientData)
{
return m_bytes.Length;
}
}