2010-10-15 5 views
31

Ich muss einen Stream mit PGP mit dem Bouncycastle-Provider verschlüsseln. Bei all den Beispielen, die ich finden kann, geht es darum, eine einfache Textdatei zu nehmen und zu verschlüsseln, aber ich werde keine Datei haben und es ist wichtig, dass der Klartext niemals auf die Festplatte geschrieben wird.Wie man einen String/Stream mit bouncycastle pgp verschlüsselt, ohne mit einer Datei zu beginnen

Die meisten der Methoden, die ich gesehen habe, sind

PGPUtil.writeFileToLiteralData verwendet, die den Klartext übergeben will. Ich würde lieber ein Byte Passin [] oder einen Inputstream.

Kann mir jemand ein Beispiel zeigen, dass

  • beginnt von String/byte []/Input
  • verschlüsselt die Zeichenfolge/byte [] zu einem outputStrem, die ich in eine Datei schreiben kann
  • ein input dechiffriert von

Falls jemand stolpert auf diese und will die volle Lösung

package com.common.security.pgp; 

import java.io.ByteArrayInputStream; 
import java.io.ByteArrayOutputStream; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
import java.security.NoSuchProviderException; 
import java.security.SecureRandom; 
import java.security.Security; 
import java.util.Date; 
import java.util.Iterator; 

import org.bouncycastle.bcpg.ArmoredOutputStream; 
import org.bouncycastle.jce.provider.BouncyCastleProvider; 
import org.bouncycastle.openpgp.PGPCompressedData; 
import org.bouncycastle.openpgp.PGPCompressedDataGenerator; 
import org.bouncycastle.openpgp.PGPEncryptedData; 
import org.bouncycastle.openpgp.PGPEncryptedDataGenerator; 
import org.bouncycastle.openpgp.PGPEncryptedDataList; 
import org.bouncycastle.openpgp.PGPException; 
import org.bouncycastle.openpgp.PGPLiteralData; 
import org.bouncycastle.openpgp.PGPLiteralDataGenerator; 
import org.bouncycastle.openpgp.PGPObjectFactory; 
import org.bouncycastle.openpgp.PGPPrivateKey; 
import org.bouncycastle.openpgp.PGPPublicKey; 
import org.bouncycastle.openpgp.PGPPublicKeyEncryptedData; 
import org.bouncycastle.openpgp.PGPPublicKeyRing; 
import org.bouncycastle.openpgp.PGPPublicKeyRingCollection; 
import org.bouncycastle.openpgp.PGPSecretKey; 
import org.bouncycastle.openpgp.PGPSecretKeyRingCollection; 
import org.bouncycastle.openpgp.PGPUtil; 

/** 
* Simple routine to encrypt and decrypt using a Public and Private key with passphrase. This service 
* routine provides the basic PGP services between byte arrays. 
* 
*/ 
public class PgpEncryption { 


    private static PGPPrivateKey findSecretKey(
      PGPSecretKeyRingCollection pgpSec, long keyID, char[] pass) 
      throws PGPException, NoSuchProviderException { 
     PGPSecretKey pgpSecKey = pgpSec.getSecretKey(keyID); 

     if (pgpSecKey == null) { 
      return null; 
     } 

     return pgpSecKey.extractPrivateKey(pass, "BC"); 
    } 

    /** 
    * decrypt the passed in message stream 
    * 
    * @param encrypted 
    *   The message to be decrypted. 
    * @param passPhrase 
    *   Pass phrase (key) 
    * 
    * @return Clear text as a byte array. I18N considerations are not handled 
    *   by this routine 
    * @exception IOException 
    * @exception PGPException 
    * @exception NoSuchProviderException 
    */ 
    public static byte[] decrypt(byte[] encrypted, InputStream keyIn, char[] password) 
      throws IOException, PGPException, NoSuchProviderException { 
     InputStream in = new ByteArrayInputStream(encrypted); 

     in = PGPUtil.getDecoderStream(in); 

     PGPObjectFactory pgpF = new PGPObjectFactory(in); 
     PGPEncryptedDataList enc = null; 
     Object o = pgpF.nextObject(); 

     // 
     // the first object might be a PGP marker packet. 
     // 
     if (o instanceof PGPEncryptedDataList) { 
      enc = (PGPEncryptedDataList) o; 
     } else { 
      enc = (PGPEncryptedDataList) pgpF.nextObject(); 
     } 



     // 
     // find the secret key 
     // 
     Iterator it = enc.getEncryptedDataObjects(); 
     PGPPrivateKey sKey = null; 
     PGPPublicKeyEncryptedData pbe = null; 
     PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(
       PGPUtil.getDecoderStream(keyIn)); 

     while (sKey == null && it.hasNext()) { 
      pbe = (PGPPublicKeyEncryptedData) it.next(); 

      sKey = findSecretKey(pgpSec, pbe.getKeyID(), password); 
     } 

     if (sKey == null) { 
      throw new IllegalArgumentException(
        "secret key for message not found."); 
     } 

     InputStream clear = pbe.getDataStream(sKey, "BC"); 



     PGPObjectFactory pgpFact = new PGPObjectFactory(clear); 

     PGPCompressedData cData = (PGPCompressedData) pgpFact.nextObject(); 

     pgpFact = new PGPObjectFactory(cData.getDataStream()); 

     PGPLiteralData ld = (PGPLiteralData) pgpFact.nextObject(); 

     InputStream unc = ld.getInputStream(); 

     ByteArrayOutputStream out = new ByteArrayOutputStream(); 
     int ch; 

     while ((ch = unc.read()) >= 0) { 
      out.write(ch); 

     } 

     byte[] returnBytes = out.toByteArray(); 
     out.close(); 
     return returnBytes; 
    } 

    /** 
    * Simple PGP encryptor between byte[]. 
    * 
    * @param clearData 
    *   The test to be encrypted 
    * @param passPhrase 
    *   The pass phrase (key). This method assumes that the key is a 
    *   simple pass phrase, and does not yet support RSA or more 
    *   sophisiticated keying. 
    * @param fileName 
    *   File name. This is used in the Literal Data Packet (tag 11) 
    *   which is really inly important if the data is to be related to 
    *   a file to be recovered later. Because this routine does not 
    *   know the source of the information, the caller can set 
    *   something here for file name use that will be carried. If this 
    *   routine is being used to encrypt SOAP MIME bodies, for 
    *   example, use the file name from the MIME type, if applicable. 
    *   Or anything else appropriate. 
    * 
    * @param armor 
    * 
    * @return encrypted data. 
    * @exception IOException 
    * @exception PGPException 
    * @exception NoSuchProviderException 
    */ 
    public static byte[] encrypt(byte[] clearData, PGPPublicKey encKey, 
      String fileName,boolean withIntegrityCheck, boolean armor) 
      throws IOException, PGPException, NoSuchProviderException { 
     if (fileName == null) { 
      fileName = PGPLiteralData.CONSOLE; 
     } 

     ByteArrayOutputStream encOut = new ByteArrayOutputStream(); 

     OutputStream out = encOut; 
     if (armor) { 
      out = new ArmoredOutputStream(out); 
     } 

     ByteArrayOutputStream bOut = new ByteArrayOutputStream(); 

     PGPCompressedDataGenerator comData = new PGPCompressedDataGenerator(
       PGPCompressedDataGenerator.ZIP); 
     OutputStream cos = comData.open(bOut); // open it with the final 
     // destination 
     PGPLiteralDataGenerator lData = new PGPLiteralDataGenerator(); 

     // we want to generate compressed data. This might be a user option 
     // later, 
     // in which case we would pass in bOut. 
     OutputStream pOut = lData.open(cos, // the compressed output stream 
       PGPLiteralData.BINARY, fileName, // "filename" to store 
       clearData.length, // length of clear data 
       new Date() // current time 
       ); 
     pOut.write(clearData); 

     lData.close(); 
     comData.close(); 

     PGPEncryptedDataGenerator cPk = new PGPEncryptedDataGenerator(
       PGPEncryptedData.CAST5, withIntegrityCheck, new SecureRandom(), 
       "BC"); 

     cPk.addMethod(encKey); 

     byte[] bytes = bOut.toByteArray(); 

     OutputStream cOut = cPk.open(out, bytes.length); 

     cOut.write(bytes); // obtain the actual bytes from the compressed stream 

     cOut.close(); 

     out.close(); 

     return encOut.toByteArray(); 
    } 

    private static PGPPublicKey readPublicKey(InputStream in) 
      throws IOException, PGPException { 
     in = PGPUtil.getDecoderStream(in); 

     PGPPublicKeyRingCollection pgpPub = new PGPPublicKeyRingCollection(in); 

     // 
     // we just loop through the collection till we find a key suitable for 
     // encryption, in the real 
     // world you would probably want to be a bit smarter about this. 
     // 

     // 
     // iterate through the key rings. 
     // 
     Iterator rIt = pgpPub.getKeyRings(); 

     while (rIt.hasNext()) { 
      PGPPublicKeyRing kRing = (PGPPublicKeyRing) rIt.next(); 
      Iterator kIt = kRing.getPublicKeys(); 

      while (kIt.hasNext()) { 
       PGPPublicKey k = (PGPPublicKey) kIt.next(); 

       if (k.isEncryptionKey()) { 
        return k; 
       } 
      } 
     } 

     throw new IllegalArgumentException(
       "Can't find encryption key in key ring."); 
    } 

    public static byte[] getBytesFromFile(File file) throws IOException { 
     InputStream is = new FileInputStream(file); 

     // Get the size of the file 
     long length = file.length(); 

     if (length > Integer.MAX_VALUE) { 
      // File is too large 
     } 

     // Create the byte array to hold the data 
     byte[] bytes = new byte[(int)length]; 

     // Read in the bytes 
     int offset = 0; 
     int numRead = 0; 
     while (offset < bytes.length 
       && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) { 
      offset += numRead; 
     } 

     // Ensure all the bytes have been read in 
     if (offset < bytes.length) { 
      throw new IOException("Could not completely read file "+file.getName()); 
     } 

     // Close the input stream and return bytes 
     is.close(); 
     return bytes; 
    } 

    public static void main(String[] args) throws Exception { 
     Security.addProvider(new BouncyCastleProvider()); 


     byte[] original = "Hello world".getBytes(); 
     System.out.println("Starting PGP test"); 

     FileInputStream pubKey = new FileInputStream("/Users/me/pub.key"); 
     byte[] encrypted = encrypt(original, readPublicKey(pubKey), null, 
       true, true); 

     FileOutputStream dfis = new FileOutputStream("/Users/me/enc.asc"); 
     dfis.write(encrypted); 
     dfis.close(); 

     byte[] encFromFile = getBytesFromFile(new File("/Users/me/enc.asc")); 
     FileInputStream secKey = new FileInputStream("/Users/me/sec.key"); 

     System.out.println("\nencrypted data = '" + new String(encrypted) + "'"); 

     byte[] decrypted = decrypt(encFromFile, secKey, "passphrase".toCharArray()); 

     System.out.println("\ndecrypted data = '" + new String(decrypted) + "'"); 


    } 
} 

Antwort

12

Mit Blick auf die source of PGPUtil können Sie sehen, was API aufrufen, wenn sie mit Strömen oder Arrays arbeiten direkt:

public static void writeFileToLiteralData(OutputStream out, 
       char fileType, File file, byte[] buffer) throws IOException { 
    PGPLiteralDataGenerator lData = new PGPLiteralDataGenerator(); 
    OutputStream pOut = lData.open(out, fileType, file.getName(), 
        new Date(file.lastModified()), buffer); 
    FileInputStream in = new FileInputStream(file); 
    byte[] buf = new byte[buffer.length]; 
    int len; 

    while ((len = in.read(buf)) > 0) { 
     pOut.write(buf, 0, len); 
    } 

    lData.close(); 
    in.close(); 
} 
+0

Yep ich dies nach aber Posting gerade gesehen würde ich lieber nicht etwas umschreiben, dass jemand jetzt schon geschrieben hat und geteilt :). Ich werde es schreiben, wenn ich muss, aber ich bin nicht in das ganze Rad Neuerfindung Szene – dstarh

+1

Stellt sich heraus, gab es eine Byte-Array-Beispiel, die Passphrasen anstelle von Pub/private verwendet, aber ich war abele das öffentlich private Beispiel mit dem Byte zu kombinieren Array Beispiel und habe es funktioniert. Eine Sache zu beachten, dass, wenn es überhaupt keine Datei gibt, Sie einfach den Dateinamen PGPLiteralData.CONSOLE statt – dstarh

+0

Broken Link verwenden können. Bitte prüfe. –

0

Ihr Code für mich sehr nützlich war. Ich arbeite in ColdFusion (mit Java) und musste Kennwörter in einer kurzen Importdatei für LDIFDE kodieren (um in Active Directory auf einem anderen Server verwendet zu werden), und ich wollte nie, dass die Kennwörter die Festplatte im Klartext berührten. Ich änderte es nur geringfügig, um zwei Funktionen hinzuzufügen, die den üblichen Anwendungsfall des Verschlüsselns einer Zeichenkette zu Datenträger und Entschlüsseln von Datenträger abstrahieren. Danke @dstarh.

import java.io.ByteArrayInputStream; 
import java.io.ByteArrayOutputStream; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
import java.security.NoSuchProviderException; 
import java.security.SecureRandom; 
import java.security.Security; 
import java.util.Date; 
import java.util.Iterator; 

import org.bouncycastle.bcpg.ArmoredOutputStream; 
import org.bouncycastle.jce.provider.BouncyCastleProvider; 
import org.bouncycastle.openpgp.PGPCompressedData; 
import org.bouncycastle.openpgp.PGPCompressedDataGenerator; 
import org.bouncycastle.openpgp.PGPEncryptedData; 
import org.bouncycastle.openpgp.PGPEncryptedDataGenerator; 
import org.bouncycastle.openpgp.PGPEncryptedDataList; 
import org.bouncycastle.openpgp.PGPException; 
import org.bouncycastle.openpgp.PGPLiteralData; 
import org.bouncycastle.openpgp.PGPLiteralDataGenerator; 
import org.bouncycastle.openpgp.PGPObjectFactory; 
import org.bouncycastle.openpgp.PGPPrivateKey; 
import org.bouncycastle.openpgp.PGPPublicKey; 
import org.bouncycastle.openpgp.PGPPublicKeyEncryptedData; 
import org.bouncycastle.openpgp.PGPPublicKeyRing; 
import org.bouncycastle.openpgp.PGPPublicKeyRingCollection; 
import org.bouncycastle.openpgp.PGPSecretKey; 
import org.bouncycastle.openpgp.PGPSecretKeyRingCollection; 
import org.bouncycastle.openpgp.PGPUtil; 

/** 
* Simple routine to encrypt and decrypt using a Public and Private key with passphrase. This service 
* routine provides the basic PGP services between byte arrays. 
* 
*/ 
public class PgpEncryption { 

    public PgpEncryption() { 
     // Empty constructor 
    } 

    private static PGPPrivateKey findSecretKey(
      PGPSecretKeyRingCollection pgpSec, long keyID, char[] pass) 
      throws PGPException, NoSuchProviderException { 
     PGPSecretKey pgpSecKey = pgpSec.getSecretKey(keyID); 

     if (pgpSecKey == null) { 
      return null; 
     } 

     return pgpSecKey.extractPrivateKey(pass, "BC"); 
    } 

    /** 
    * decrypt the passed in message stream 
    * 
    * @param encrypted 
    *   The message to be decrypted. 
    * @param passPhrase 
    *   Pass phrase (key) 
    * 
    * @return Clear text as a byte array. I18N considerations are not handled 
    *   by this routine 
    * @exception IOException 
    * @exception PGPException 
    * @exception NoSuchProviderException 
    */ 
    public static byte[] decrypt(byte[] encrypted, InputStream keyIn, char[] password) 
      throws IOException, PGPException, NoSuchProviderException { 
     InputStream in = new ByteArrayInputStream(encrypted); 

     in = PGPUtil.getDecoderStream(in); 

     PGPObjectFactory pgpF = new PGPObjectFactory(in); 
     PGPEncryptedDataList enc = null; 
     Object o = pgpF.nextObject(); 

     // 
     // the first object might be a PGP marker packet. 
     // 
     if (o instanceof PGPEncryptedDataList) { 
      enc = (PGPEncryptedDataList) o; 
     } else { 
      enc = (PGPEncryptedDataList) pgpF.nextObject(); 
     } 



     // 
     // find the secret key 
     // 
     Iterator it = enc.getEncryptedDataObjects(); 
     PGPPrivateKey sKey = null; 
     PGPPublicKeyEncryptedData pbe = null; 
     PGPSecretKeyRingCollection pgpSec = new PGPSecretKeyRingCollection(
       PGPUtil.getDecoderStream(keyIn)); 

     while (sKey == null && it.hasNext()) { 
      pbe = (PGPPublicKeyEncryptedData) it.next(); 

      sKey = findSecretKey(pgpSec, pbe.getKeyID(), password); 
     } 

     if (sKey == null) { 
      throw new IllegalArgumentException(
        "secret key for message not found."); 
     } 

     InputStream clear = pbe.getDataStream(sKey, "BC"); 



     PGPObjectFactory pgpFact = new PGPObjectFactory(clear); 

     PGPCompressedData cData = (PGPCompressedData) pgpFact.nextObject(); 

     pgpFact = new PGPObjectFactory(cData.getDataStream()); 

     PGPLiteralData ld = (PGPLiteralData) pgpFact.nextObject(); 

     InputStream unc = ld.getInputStream(); 

     ByteArrayOutputStream out = new ByteArrayOutputStream(); 
     int ch; 

     while ((ch = unc.read()) >= 0) { 
      out.write(ch); 

     } 

     byte[] returnBytes = out.toByteArray(); 
     out.close(); 
     return returnBytes; 
    } 

    /** 
    * Simple PGP encryptor between byte[]. 
    * 
    * @param clearData 
    *   The test to be encrypted 
    * @param passPhrase 
    *   The pass phrase (key). This method assumes that the key is a 
    *   simple pass phrase, and does not yet support RSA or more 
    *   sophisiticated keying. 
    * @param fileName 
    *   File name. This is used in the Literal Data Packet (tag 11) 
    *   which is really inly important if the data is to be related to 
    *   a file to be recovered later. Because this routine does not 
    *   know the source of the information, the caller can set 
    *   something here for file name use that will be carried. If this 
    *   routine is being used to encrypt SOAP MIME bodies, for 
    *   example, use the file name from the MIME type, if applicable. 
    *   Or anything else appropriate. 
    * 
    * @param armor 
    * 
    * @return encrypted data. 
    * @exception IOException 
    * @exception PGPException 
    * @exception NoSuchProviderException 
    */ 
    public static byte[] encrypt(byte[] clearData, PGPPublicKey encKey, 
      String fileName,boolean withIntegrityCheck, boolean armor) 
      throws IOException, PGPException, NoSuchProviderException { 
     if (fileName == null) { 
      fileName = PGPLiteralData.CONSOLE; 
     } 

     ByteArrayOutputStream encOut = new ByteArrayOutputStream(); 

     OutputStream out = encOut; 
     if (armor) { 
      out = new ArmoredOutputStream(out); 
     } 

     ByteArrayOutputStream bOut = new ByteArrayOutputStream(); 

     PGPCompressedDataGenerator comData = new PGPCompressedDataGenerator(
       PGPCompressedDataGenerator.ZIP); 
     OutputStream cos = comData.open(bOut); // open it with the final 
     // destination 
     PGPLiteralDataGenerator lData = new PGPLiteralDataGenerator(); 

     // we want to generate compressed data. This might be a user option 
     // later, 
     // in which case we would pass in bOut. 
     OutputStream pOut = lData.open(cos, // the compressed output stream 
       PGPLiteralData.BINARY, fileName, // "filename" to store 
       clearData.length, // length of clear data 
       new Date() // current time 
       ); 
     pOut.write(clearData); 

     lData.close(); 
     comData.close(); 

     PGPEncryptedDataGenerator cPk = new PGPEncryptedDataGenerator(
       PGPEncryptedData.CAST5, withIntegrityCheck, new SecureRandom(), 
       "BC"); 

     cPk.addMethod(encKey); 

     byte[] bytes = bOut.toByteArray(); 

     OutputStream cOut = cPk.open(out, bytes.length); 

     cOut.write(bytes); // obtain the actual bytes from the compressed stream 

     cOut.close(); 

     out.close(); 

     return encOut.toByteArray(); 
    } 

    private static PGPPublicKey readPublicKey(InputStream in) 
      throws IOException, PGPException { 
     in = PGPUtil.getDecoderStream(in); 

     PGPPublicKeyRingCollection pgpPub = new PGPPublicKeyRingCollection(in); 

     // 
     // we just loop through the collection till we find a key suitable for 
     // encryption, in the real 
     // world you would probably want to be a bit smarter about this. 
     // 

     // 
     // iterate through the key rings. 
     // 
     Iterator rIt = pgpPub.getKeyRings(); 

     while (rIt.hasNext()) { 
      PGPPublicKeyRing kRing = (PGPPublicKeyRing) rIt.next(); 
      Iterator kIt = kRing.getPublicKeys(); 

      while (kIt.hasNext()) { 
       PGPPublicKey k = (PGPPublicKey) kIt.next(); 

       if (k.isEncryptionKey()) { 
        return k; 
       } 
      } 
     } 

     throw new IllegalArgumentException(
       "Can't find encryption key in key ring."); 
    } 

    public static byte[] getBytesFromFile(File file) throws IOException { 
     InputStream is = new FileInputStream(file); 

     // Get the size of the file 
     long length = file.length(); 

     if (length > Integer.MAX_VALUE) { 
      // File is too large 
     } 

     // Create the byte array to hold the data 
     byte[] bytes = new byte[(int)length]; 

     // Read in the bytes 
     int offset = 0; 
     int numRead = 0; 
     while (offset < bytes.length 
       && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) { 
      offset += numRead; 
     } 

     // Ensure all the bytes have been read in 
     if (offset < bytes.length) { 
      throw new IOException("Could not completely read file "+file.getName()); 
     } 

     // Close the input stream and return bytes 
     is.close(); 
     return bytes; 
    } 

    public static String encryptToFile(String inputStr, String keyFile, String outFile) throws Exception { 
     Security.addProvider(new BouncyCastleProvider()); 

     byte[] original = inputStr.getBytes(); 

     FileInputStream pubKey = new FileInputStream(keyFile); 
     byte[] encrypted = encrypt(original, readPublicKey(pubKey), null, 
       true, true); 

     FileOutputStream dfis = new FileOutputStream(outFile); 
     dfis.write(encrypted); 
     dfis.close(); 

     return new String(encrypted); 
    } 

    public static String decryptFromFile(String passphrase, String keyFile, String inputFile) throws Exception { 
     Security.addProvider(new BouncyCastleProvider()); 

     byte[] encFromFile = getBytesFromFile(new File(inputFile)); 
     FileInputStream secKey = new FileInputStream(keyFile); 

     byte[] decrypted = decrypt(encFromFile, secKey, passphrase.toCharArray()); 

     return new String(decrypted); 
    } 

    public static void main(String[] args) throws Exception { 
     String encrypted = encryptToFile("Hello world","pub.asc","enc.asc"); 
     System.out.println("\nencrypted data = '" + new String(encrypted) + "'"); 

     String decrypted = decryptFromFile("open sesame", "secret.asc", "enc.asc"); 
     System.out.println("\ndecrypted data = '" + decrypted + "'"); 

    } 
} 
+2

Dies ist nicht wirklich eine Antwort auf meine Frage, noch ist es in den SO-Richtlinien wirklich angemessen. Die Frage bezog sich speziell darauf, NICHT in eine Datei zu schreiben, und Ihr Beispiel fügt die Fähigkeit hinzu, in und aus einer Datei zu schreiben, von der es an anderer Stelle viele Beispiele gibt. Es scheint kein kanonisches Beispiel dafür zu geben, wie man das nur in der Erinnerung macht. – dstarh

2

bei grepcode repository - payneteasy superfly sources Gefunden

private static void writeBytesToLiteralData(OutputStream out, 
    char fileType, String name, byte[] bytes) throws IOException { 
     PGPLiteralDataGenerator lData = new PGPLiteralDataGenerator(); 
     OutputStream pOut = lData.open(out, fileType, name,bytes.length, new Date()); 
     pOut.write(bytes); 
} 
Verwandte Themen