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package de.thedevstack.conversationsplus.utils;
import android.os.Bundle;
import android.util.Pair;
import org.bouncycastle.asn1.x500.X500Name;
import org.bouncycastle.asn1.x500.style.BCStyle;
import org.bouncycastle.asn1.x500.style.IETFUtils;
import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
import java.security.MessageDigest;
import java.security.cert.CertificateEncodingException;
import java.security.cert.CertificateParsingException;
import java.security.cert.X509Certificate;
import java.text.Normalizer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import de.thedevstack.conversationsplus.Config;
import de.thedevstack.conversationsplus.R;
import de.thedevstack.conversationsplus.entities.Message;
import de.thedevstack.conversationsplus.xmpp.jid.InvalidJidException;
import de.thedevstack.conversationsplus.xmpp.jid.Jid;
public final class CryptoHelper {
public static final String FILETRANSFER = "?FILETRANSFERv1:";
private final static char[] hexArray = "0123456789abcdef".toCharArray();
final public static byte[] ONE = new byte[] { 0, 0, 0, 1 };
public static String bytesToHex(byte[] bytes) {
char[] hexChars = new char[bytes.length * 2];
for (int j = 0; j < bytes.length; j++) {
int v = bytes[j] & 0xFF;
hexChars[j * 2] = hexArray[v >>> 4];
hexChars[j * 2 + 1] = hexArray[v & 0x0F];
}
return new String(hexChars);
}
public static byte[] hexToBytes(String hexString) {
int len = hexString.length();
byte[] array = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
array[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4) + Character
.digit(hexString.charAt(i + 1), 16));
}
return array;
}
public static String hexToString(final String hexString) {
return new String(hexToBytes(hexString));
}
public static byte[] concatenateByteArrays(byte[] a, byte[] b) {
byte[] result = new byte[a.length + b.length];
System.arraycopy(a, 0, result, 0, a.length);
System.arraycopy(b, 0, result, a.length, b.length);
return result;
}
/**
* Escapes usernames or passwords for SASL.
*/
public static String saslEscape(final String s) {
final StringBuilder sb = new StringBuilder((int) (s.length() * 1.1));
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
switch (c) {
case ',':
sb.append("=2C");
break;
case '=':
sb.append("=3D");
break;
default:
sb.append(c);
break;
}
}
return sb.toString();
}
public static String saslPrep(final String s) {
return Normalizer.normalize(s, Normalizer.Form.NFKC);
}
public static String prettifyFingerprint(String fingerprint) {
if (fingerprint==null) {
return "";
} else if (fingerprint.length() < 40) {
return fingerprint;
}
StringBuilder builder = new StringBuilder(fingerprint.toLowerCase(Locale.US).replaceAll("\\s", ""));
for(int i=8;i<builder.length();i+=9) {
builder.insert(i, ' ');
}
return builder.toString();
}
public static String prettifyFingerprintCert(String fingerprint) {
StringBuilder builder = new StringBuilder(fingerprint);
for(int i=2;i < builder.length(); i+=3) {
builder.insert(i,':');
}
return builder.toString();
}
public static String[] getOrderedCipherSuites(final String[] platformSupportedCipherSuites) {
final Collection<String> cipherSuites = new LinkedHashSet<>(Arrays.asList(Config.ENABLED_CIPHERS));
final List<String> platformCiphers = Arrays.asList(platformSupportedCipherSuites);
cipherSuites.retainAll(platformCiphers);
cipherSuites.addAll(platformCiphers);
filterWeakCipherSuites(cipherSuites);
return cipherSuites.toArray(new String[cipherSuites.size()]);
}
private static void filterWeakCipherSuites(final Collection<String> cipherSuites) {
final Iterator<String> it = cipherSuites.iterator();
while (it.hasNext()) {
String cipherName = it.next();
// remove all ciphers with no or very weak encryption or no authentication
for (String weakCipherPattern : Config.WEAK_CIPHER_PATTERNS) {
if (cipherName.contains(weakCipherPattern)) {
it.remove();
break;
}
}
}
}
public static Pair<Jid,String> extractJidAndName(X509Certificate certificate) throws CertificateEncodingException, InvalidJidException, CertificateParsingException {
Collection<List<?>> alternativeNames = certificate.getSubjectAlternativeNames();
List<String> emails = new ArrayList<>();
if (alternativeNames != null) {
for(List<?> san : alternativeNames) {
Integer type = (Integer) san.get(0);
if (type == 1) {
emails.add((String) san.get(1));
}
}
}
X500Name x500name = new JcaX509CertificateHolder(certificate).getSubject();
if (emails.size() == 0) {
emails.add(IETFUtils.valueToString(x500name.getRDNs(BCStyle.EmailAddress)[0].getFirst().getValue()));
}
String name = IETFUtils.valueToString(x500name.getRDNs(BCStyle.CN)[0].getFirst().getValue());
if (emails.size() >= 1) {
return new Pair<>(Jid.fromString(emails.get(0)), name);
} else {
return null;
}
}
public static Bundle extractCertificateInformation(X509Certificate certificate) {
Bundle information = new Bundle();
try {
JcaX509CertificateHolder holder = new JcaX509CertificateHolder(certificate);
X500Name subject = holder.getSubject();
try {
information.putString("subject_cn", subject.getRDNs(BCStyle.CN)[0].getFirst().getValue().toString());
} catch (Exception e) {
//ignored
}
try {
information.putString("subject_o",subject.getRDNs(BCStyle.O)[0].getFirst().getValue().toString());
} catch (Exception e) {
//ignored
}
X500Name issuer = holder.getIssuer();
try {
information.putString("issuer_cn", issuer.getRDNs(BCStyle.CN)[0].getFirst().getValue().toString());
} catch (Exception e) {
//ignored
}
try {
information.putString("issuer_o", issuer.getRDNs(BCStyle.O)[0].getFirst().getValue().toString());
} catch (Exception e) {
//ignored
}
try {
MessageDigest md = MessageDigest.getInstance("SHA-1");
byte[] fingerprint = md.digest(certificate.getEncoded());
information.putString("sha1", prettifyFingerprintCert(bytesToHex(fingerprint)));
} catch (Exception e) {
}
return information;
} catch (CertificateEncodingException e) {
return information;
}
}
public static int encryptionTypeToText(int encryption) {
switch (encryption) {
case Message.ENCRYPTION_OTR:
return R.string.encryption_choice_otr;
case Message.ENCRYPTION_AXOLOTL:
return R.string.encryption_choice_omemo;
case Message.ENCRYPTION_NONE:
return R.string.encryption_choice_unencrypted;
default:
return R.string.encryption_choice_pgp;
}
}
}
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