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refactor encryption/decryption to Render class

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This commit is contained in:
Harald Hoyer 2014-07-31 13:28:57 +02:00
parent 34056b9ab8
commit cdbb309f4d
2 changed files with 109 additions and 40 deletions
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61
app/src/main/java/org/surfsite/android/secretshare/GenerateFragment.java
View file

@ -1,15 +1,11 @@
package org.surfsite.android.secretshare;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Fragment;
import android.content.DialogInterface;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.print.PrintHelper;
import android.util.Base64;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
@ -19,9 +15,8 @@ import android.widget.TextView;
import com.tiemens.secretshare.engine.SecretShare;
import com.tiemens.secretshare.engine.SecretShare.ShareInfo;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.List;
@ -66,17 +61,6 @@ public class GenerateFragment extends Fragment implements FragmentSupport {
return fragment;
}
static BigInteger stringToBigInteger(String in) {
BigInteger bigint;
try {
bigint = new BigInteger(in.getBytes("UTF-8"));
} catch (UnsupportedEncodingException ex) {
ex.printStackTrace();
bigint = BigInteger.ZERO;
}
return bigint;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
@ -163,6 +147,8 @@ public class GenerateFragment extends Fragment implements FragmentSupport {
private class GenerateSharesTask extends AsyncTask<Void, Void, Void> {
private final Activity activity;
SecretShare.PublicInfo pi = null;
ShareInfo si[];
private TextView tv;
private List<SecretShare.ShareInfo> pieces;
private int n;
@ -179,6 +165,7 @@ public class GenerateFragment extends Fragment implements FragmentSupport {
this.n = n;
this.k = k;
this.cleartext = cleartext;
si = new ShareInfo[n];
this.tv.setText("Generating shared secrets for " + cleartext.length()
+ " chars. Please Wait. This can take a long time.");
}
@ -189,7 +176,7 @@ public class GenerateFragment extends Fragment implements FragmentSupport {
@Override
protected Void doInBackground(Void... params) {
final BigInteger secretInteger = stringToBigInteger(cleartext);
final BigInteger secretInteger = Renderer.stringToBigInteger(cleartext);
final BigInteger modulus;
modulus = SecretShare.createAppropriateModulusForSecret(secretInteger);
@ -211,32 +198,20 @@ public class GenerateFragment extends Fragment implements FragmentSupport {
for (int i = 0; i < out.length; i++) {
final ShareInfo piece = pieces.get(i);
byte[] bmodulus = publicInfo.getPrimeModulus().toByteArray();
byte[] bshare = piece.getShare().toByteArray();
int blen = 4 + 4 + 4 + 4 + 4 + bmodulus.length + bshare.length;
final ByteBuffer bencoded = ByteBuffer.allocate(blen);
bencoded.putInt(n).putInt(k).putInt(piece.getX());
bencoded.putInt(bmodulus.length).put(bmodulus);
bencoded.putInt(bshare.length).put(bshare);
final String data = Renderer.encodeShareInfo(piece);
tv.append("Length: " + blen + "\n");
out[i] = n + ":" + k + ":" + piece.getX() + ":"
out[i] = "ssss-android:" + piece.getX() + "/" + k + ":" + n + "-"
+ publicInfo.getDescription()
+ publicInfo.getPrimeModulus() + ":" + piece.getShare();
tv.append("OutLen: " + out[i].length() + "\n");
tv.append(out[i] + "\n");
tv.append(bencoded + "\n0x");
for (byte b : bencoded.array()) {
tv.append(String.format("%x", b));
}
tv.append("\n");
String bencoded64 = Base64.encodeToString(bencoded.array(), Base64.DEFAULT);
tv.append("B64Len: " + bencoded64.length() + "\n");
tv.append(bencoded64 + "\n");
tv.append(bencoded + "\n\n");
tv.append("B64Len: " + data.length() + "\n");
tv.append(data + "\n");
if (pi == null)
pi = Renderer.decodePublicInfo(data);
final String data = "ssss-android:" + bencoded64;
si[n] = Renderer.decodeShareInfo(data, pi);
/*
if (i == 0) {
View view = activity.getLayoutInflater().inflate(R.layout.address_qr, null);
final TextView tv = (TextView) view.findViewById(R.id.secret_text);
@ -259,8 +234,14 @@ public class GenerateFragment extends Fragment implements FragmentSupport {
builder.show();
}
*/
}
List<ShareInfo> li = new ArrayList<ShareInfo>();
li.add(si[0]);
li.add(si[1]);
li.add(si[2]);
final SecretShare.CombineOutput combineOutput = new SecretShare(pi)
.combine(li);
this.finished = true;
}
}

88
app/src/main/java/org/surfsite/android/secretshare/Renderer.java
View file

@ -9,12 +9,17 @@ import android.graphics.Rect;
import android.os.AsyncTask;
import android.support.v4.print.PrintHelper;
import android.text.TextPaint;
import android.util.Base64;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.aztec.AztecWriter;
import com.google.zxing.common.BitMatrix;
import com.tiemens.secretshare.engine.SecretShare;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.security.InvalidParameterException;
import java.util.ArrayList;
import java.util.Hashtable;
@ -180,4 +185,87 @@ public class Renderer {
return lines;
}
static BigInteger stringToBigInteger(String in) {
return new BigInteger(in.getBytes());
}
public static String encodeShareInfo(final SecretShare.ShareInfo piece) {
final SecretShare.PublicInfo publicInfo = piece.getPublicInfo();
final byte[] bytePrimeModulus = publicInfo.getPrimeModulus().toByteArray();
final byte[] byteShare = piece.getShare().toByteArray();
final byte[] byteDescription = publicInfo.getDescription().getBytes();
final int byteLen = 4 + 4 + 4
+ (4 + byteDescription.length)
+ (4 + bytePrimeModulus.length)
+ (4 + byteShare.length);
final ByteBuffer byteBuffer = ByteBuffer.allocate(byteLen);
byteBuffer.putInt(piece.getX());
byteBuffer.putInt(publicInfo.getK());
byteBuffer.putInt(publicInfo.getN());
byteBuffer.putInt(byteDescription.length).put(byteDescription);
byteBuffer.putInt(bytePrimeModulus.length).put(bytePrimeModulus);
byteBuffer.putInt(byteShare.length).put(byteShare);
final String byteEncoded64 = Base64.encodeToString(byteBuffer.array(), Base64.DEFAULT);
return "ssss-android:" + piece.getX() + "/" + publicInfo.getK()
+ ":" + publicInfo.getN() + "=" + byteEncoded64;
}
public static SecretShare.PublicInfo decodePublicInfo(final String buf) {
int index64 = buf.indexOf("=") + 1;
String substr = buf.substring(index64);
final byte[] decodeBytes = Base64.decode(substr, Base64.DEFAULT);
final ByteBuffer byteBuffer = ByteBuffer.wrap(decodeBytes);
int x = byteBuffer.getInt();
int k = byteBuffer.getInt();
int n = byteBuffer.getInt();
int byteDescriptionLength = byteBuffer.getInt();
final byte[] byteDescription = new byte[byteDescriptionLength];
byteBuffer.get(byteDescription);
int bytePrimeModulusLength = byteBuffer.getInt();
final byte[] bytePrimeModulus = new byte[bytePrimeModulusLength];
byteBuffer.get(bytePrimeModulus);
BigInteger inPrimeModulus = new BigInteger(bytePrimeModulus);
return new SecretShare.PublicInfo(n, k, inPrimeModulus, new String(byteDescription));
}
public static SecretShare.ShareInfo decodeShareInfo(final String buf, final SecretShare.PublicInfo publicInfo) throws InvalidParameterException {
int index64 = buf.indexOf("=") + 1;
final ByteBuffer byteBuffer = ByteBuffer.wrap(Base64.decode(buf.substring(index64), Base64.DEFAULT));
int x = byteBuffer.getInt();
int k = byteBuffer.getInt();
int n = byteBuffer.getInt();
if (n != publicInfo.getN()) {
throw new InvalidParameterException("SecretShare.PublicInfo.N does not match.");
}
if (k != publicInfo.getK()) {
throw new InvalidParameterException("SecretShare.PublicInfo.K does not match.");
}
if (x > n) {
throw new InvalidParameterException("SecretShare x > n.");
}
int byteDescriptionLength = byteBuffer.getInt();
final byte[] byteDescription = new byte[byteDescriptionLength];
byteBuffer.get(byteDescription);
if (publicInfo.getDescription().compareTo(new String(byteDescription)) != 0) {
throw new InvalidParameterException("SecretShare.PublicInfo.Description does not match.");
}
int bytePrimeModulusLength = byteBuffer.getInt();
final byte[] bytePrimeModulus = new byte[bytePrimeModulusLength];
byteBuffer.get(bytePrimeModulus);
BigInteger inPrimeModulus = new BigInteger(bytePrimeModulus);
if (inPrimeModulus.compareTo(publicInfo.getPrimeModulus()) != 0) {
throw new InvalidParameterException("SecretShare.PublicInfo.PrimeModulus does not match.");
}
int byteShareLength = byteBuffer.getInt();
final byte[] byteShare = new byte[byteShareLength];
byteBuffer.get(byteShare);
BigInteger inShare = new BigInteger(byteShare);
return new SecretShare.ShareInfo(x, inShare, publicInfo);
}
}