bcprov/src/main/java/org/bouncycastle/crypto/engines/DESedeWrapEngine.java - platform/external/bouncycastle - Git at Google

 package org.bouncycastle.crypto.engines;

 import java.security.SecureRandom;

 import org.bouncycastle.crypto.CipherParameters;
 import org.bouncycastle.crypto.Digest;
 import org.bouncycastle.crypto.InvalidCipherTextException;
 import org.bouncycastle.crypto.Wrapper;
 // BEGIN android-changed
 import org.bouncycastle.crypto.digests.AndroidDigestFactory;
 // END android-changed
 import org.bouncycastle.crypto.modes.CBCBlockCipher;
 import org.bouncycastle.crypto.params.KeyParameter;
 import org.bouncycastle.crypto.params.ParametersWithIV;
 import org.bouncycastle.crypto.params.ParametersWithRandom;
 import org.bouncycastle.util.Arrays;

 /**
  * Wrap keys according to
  * <A HREF="http://www.ietf.org/internet-drafts/draft-ietf-smime-key-wrap-01.txt">
  * draft-ietf-smime-key-wrap-01.txt</A>.
  * <p>
  * Note:
  * <ul>
  * <li>this is based on a draft, and as such is subject to change - don't use this class for anything requiring long term storage.
  * <li>if you are using this to wrap triple-des keys you need to set the
  * parity bits on the key and, if it's a two-key triple-des key, pad it
  * yourself.
  * </ul>
  */
 public class DESedeWrapEngine
     implements Wrapper
 {
    /** Field engine */
    private CBCBlockCipher engine;

    /** Field param */
    private KeyParameter param;

    /** Field paramPlusIV */
    private ParametersWithIV paramPlusIV;

    /** Field iv */
    private byte[] iv;

    /** Field forWrapping */
    private boolean forWrapping;

    /** Field IV2           */
    private static final byte[] IV2 = { (byte) 0x4a, (byte) 0xdd, (byte) 0xa2,
                                        (byte) 0x2c, (byte) 0x79, (byte) 0xe8,
                                        (byte) 0x21, (byte) 0x05 };

     //
     // checksum digest
     //
     // BEGIN android-changed
     Digest  sha1 = AndroidDigestFactory.getSHA1();
     // END android-changed
     byte[]  digest = new byte[20];

    /**
     * Method init
     *
     * @param forWrapping true if for wrapping, false otherwise.
     * @param param necessary parameters, may include KeyParameter, ParametersWithRandom, and ParametersWithIV
     */
     public void init(boolean forWrapping, CipherParameters param)
     {

         this.forWrapping = forWrapping;
         this.engine = new CBCBlockCipher(new DESedeEngine());

         SecureRandom sr;
         if (param instanceof ParametersWithRandom)
         {
             ParametersWithRandom pr = (ParametersWithRandom) param;
             param = pr.getParameters();
             sr = pr.getRandom();
         }
         else
         {
             sr = new SecureRandom();
         }

         if (param instanceof KeyParameter)
         {
             this.param = (KeyParameter)param;

             if (this.forWrapping)
             {

                 // Hm, we have no IV but we want to wrap ?!?
                 // well, then we have to create our own IV.
                 this.iv = new byte[8];
                 sr.nextBytes(iv);

                 this.paramPlusIV = new ParametersWithIV(this.param, this.iv);
             }
         }
         else if (param instanceof ParametersWithIV)
         {
             this.paramPlusIV = (ParametersWithIV)param;
             this.iv = this.paramPlusIV.getIV();
             this.param = (KeyParameter)this.paramPlusIV.getParameters();

             if (this.forWrapping)
             {
                 if ((this.iv == null) || (this.iv.length != 8))
                 {
                     throw new IllegalArgumentException("IV is not 8 octets");
                 }
             }
             else
             {
                 throw new IllegalArgumentException(
                         "You should not supply an IV for unwrapping");
             }
         }
     }

    /**
     * Method getAlgorithmName
     *
     * @return the algorithm name "DESede".
     */
    public String getAlgorithmName()
    {
       return "DESede";
    }

    /**
     * Method wrap
     *
     * @param in byte array containing the encoded key.
     * @param inOff off set into in that the data starts at.
     * @param inLen  length of the data.
     * @return the wrapped bytes.
     */
    public byte[] wrap(byte[] in, int inOff, int inLen)
    {
       if (!forWrapping)
       {
          throw new IllegalStateException("Not initialized for wrapping");
       }

       byte keyToBeWrapped[] = new byte[inLen];

       System.arraycopy(in, inOff, keyToBeWrapped, 0, inLen);

       // Compute the CMS Key Checksum, (section 5.6.1), call this CKS.
       byte[] CKS = calculateCMSKeyChecksum(keyToBeWrapped);

       // Let WKCKS = WK || CKS where || is concatenation.
       byte[] WKCKS = new byte[keyToBeWrapped.length + CKS.length];

       System.arraycopy(keyToBeWrapped, 0, WKCKS, 0, keyToBeWrapped.length);
       System.arraycopy(CKS, 0, WKCKS, keyToBeWrapped.length, CKS.length);

       // Encrypt WKCKS in CBC mode using KEK as the key and IV as the
       // initialization vector. Call the results TEMP1.

       int blockSize = engine.getBlockSize();

       if (WKCKS.length % blockSize != 0)
       {
          throw new IllegalStateException("Not multiple of block length");
       }

       engine.init(true, paramPlusIV);

       byte TEMP1[] = new byte[WKCKS.length];

       for (int currentBytePos = 0; currentBytePos != WKCKS.length; currentBytePos += blockSize)
       {
          engine.processBlock(WKCKS, currentBytePos, TEMP1, currentBytePos);
       }

       // Let TEMP2 = IV || TEMP1.
       byte[] TEMP2 = new byte[this.iv.length + TEMP1.length];

       System.arraycopy(this.iv, 0, TEMP2, 0, this.iv.length);
       System.arraycopy(TEMP1, 0, TEMP2, this.iv.length, TEMP1.length);

       // Reverse the order of the octets in TEMP2 and call the result TEMP3.
       byte[] TEMP3 = reverse(TEMP2);

       // Encrypt TEMP3 in CBC mode using the KEK and an initialization vector
       // of 0x 4a dd a2 2c 79 e8 21 05. The resulting cipher text is the desired
       // result. It is 40 octets long if a 168 bit key is being wrapped.
       ParametersWithIV param2 = new ParametersWithIV(this.param, IV2);

       this.engine.init(true, param2);

       for (int currentBytePos = 0; currentBytePos != TEMP3.length; currentBytePos += blockSize)
       {
          engine.processBlock(TEMP3, currentBytePos, TEMP3, currentBytePos);
       }

       return TEMP3;
    }

    /**
     * Method unwrap
     *
     * @param in byte array containing the wrapped key.
     * @param inOff off set into in that the data starts at.
     * @param inLen  length of the data.
     * @return the unwrapped bytes.
     * @throws InvalidCipherTextException
     */
     public byte[] unwrap(byte[] in, int inOff, int inLen)
            throws InvalidCipherTextException
     {
         if (forWrapping)
         {
             throw new IllegalStateException("Not set for unwrapping");
         }

         if (in == null)
         {
             throw new InvalidCipherTextException("Null pointer as ciphertext");
         }

         final int blockSize = engine.getBlockSize();
         if (inLen % blockSize != 0)
         {
             throw new InvalidCipherTextException("Ciphertext not multiple of " + blockSize);
         }

       /*
       // Check if the length of the cipher text is reasonable given the key
       // type. It must be 40 bytes for a 168 bit key and either 32, 40, or
       // 48 bytes for a 128, 192, or 256 bit key. If the length is not supported
       // or inconsistent with the algorithm for which the key is intended,
       // return error.
       //
       // we do not accept 168 bit keys. it has to be 192 bit.
       int lengthA = (estimatedKeyLengthInBit / 8) + 16;
       int lengthB = estimatedKeyLengthInBit % 8;

       if ((lengthA != keyToBeUnwrapped.length) || (lengthB != 0)) {
          throw new XMLSecurityException("empty");
       }
       */

       // Decrypt the cipher text with TRIPLedeS in CBC mode using the KEK
       // and an initialization vector (IV) of 0x4adda22c79e82105. Call the output TEMP3.
       ParametersWithIV param2 = new ParametersWithIV(this.param, IV2);

       this.engine.init(false, param2);

       byte TEMP3[] = new byte[inLen];

       for (int currentBytePos = 0; currentBytePos != inLen; currentBytePos += blockSize)
       {
          engine.processBlock(in, inOff + currentBytePos, TEMP3, currentBytePos);
       }

       // Reverse the order of the octets in TEMP3 and call the result TEMP2.
       byte[] TEMP2 = reverse(TEMP3);

       // Decompose TEMP2 into IV, the first 8 octets, and TEMP1, the remaining octets.
       this.iv = new byte[8];

       byte[] TEMP1 = new byte[TEMP2.length - 8];

       System.arraycopy(TEMP2, 0, this.iv, 0, 8);
       System.arraycopy(TEMP2, 8, TEMP1, 0, TEMP2.length - 8);

       // Decrypt TEMP1 using TRIPLedeS in CBC mode using the KEK and the IV
       // found in the previous step. Call the result WKCKS.
       this.paramPlusIV = new ParametersWithIV(this.param, this.iv);

       this.engine.init(false, this.paramPlusIV);

       byte[] WKCKS = new byte[TEMP1.length];

       for (int currentBytePos = 0; currentBytePos != WKCKS.length; currentBytePos += blockSize)
       {
          engine.processBlock(TEMP1, currentBytePos, WKCKS, currentBytePos);
       }

       // Decompose WKCKS. CKS is the last 8 octets and WK, the wrapped key, are
       // those octets before the CKS.
       byte[] result = new byte[WKCKS.length - 8];
       byte[] CKStoBeVerified = new byte[8];

       System.arraycopy(WKCKS, 0, result, 0, WKCKS.length - 8);
       System.arraycopy(WKCKS, WKCKS.length - 8, CKStoBeVerified, 0, 8);

       // Calculate a CMS Key Checksum, (section 5.6.1), over the WK and compare
       // with the CKS extracted in the above step. If they are not equal, return error.
       if (!checkCMSKeyChecksum(result, CKStoBeVerified))
       {
          throw new InvalidCipherTextException(
             "Checksum inside ciphertext is corrupted");
       }

       // WK is the wrapped key, now extracted for use in data decryption.
       return result;
    }

     /**
      * Some key wrap algorithms make use of the Key Checksum defined
      * in CMS [CMS-Algorithms]. This is used to provide an integrity
      * check value for the key being wrapped. The algorithm is
      *
      * - Compute the 20 octet SHA-1 hash on the key being wrapped.
      * - Use the first 8 octets of this hash as the checksum value.
      *
      * For details see http://www.w3.org/TR/xmlenc-core/#sec-CMSKeyChecksum.
      *
      * @param key the key to check,
      * @return the CMS checksum.
      * @throws RuntimeException
      */
     private byte[] calculateCMSKeyChecksum(
         byte[] key)
     {
         byte[]  result = new byte[8];

         sha1.update(key, 0, key.length);
         sha1.doFinal(digest, 0);

         System.arraycopy(digest, 0, result, 0, 8);

         return result;
     }

     /**
      * For details see http://www.w3.org/TR/xmlenc-core/#sec-CMSKeyChecksum
      *
      * @param key key to be validated.
      * @param checksum the checksum.
      * @return true if okay, false otherwise.
      */
     private boolean checkCMSKeyChecksum(
         byte[] key,
         byte[] checksum)
     {
         return Arrays.constantTimeAreEqual(calculateCMSKeyChecksum(key), checksum);
     }

     private static byte[] reverse(byte[] bs)
     {
         byte[] result = new byte[bs.length];
         for (int i = 0; i < bs.length; i++)
         {
            result[i] = bs[bs.length - (i + 1)];
         }
         return result;
     }
 }
	package org.bouncycastle.crypto.engines;

	import java.security.SecureRandom;

	import org.bouncycastle.crypto.CipherParameters;
	import org.bouncycastle.crypto.Digest;
	import org.bouncycastle.crypto.InvalidCipherTextException;
	import org.bouncycastle.crypto.Wrapper;
	// BEGIN android-changed
	import org.bouncycastle.crypto.digests.AndroidDigestFactory;
	// END android-changed
	import org.bouncycastle.crypto.modes.CBCBlockCipher;
	import org.bouncycastle.crypto.params.KeyParameter;
	import org.bouncycastle.crypto.params.ParametersWithIV;
	import org.bouncycastle.crypto.params.ParametersWithRandom;
	import org.bouncycastle.util.Arrays;

	/**
	* Wrap keys according to
	* <A HREF="http://www.ietf.org/internet-drafts/draft-ietf-smime-key-wrap-01.txt">
	* draft-ietf-smime-key-wrap-01.txt</A>.
	* <p>
	* Note:
	* <ul>
	* <li>this is based on a draft, and as such is subject to change - don't use this class for anything requiring long term storage.
	* <li>if you are using this to wrap triple-des keys you need to set the
	* parity bits on the key and, if it's a two-key triple-des key, pad it
	* yourself.
	* </ul>
	*/
	public class DESedeWrapEngine
	implements Wrapper
	{
	/** Field engine */
	private CBCBlockCipher engine;

	/** Field param */
	private KeyParameter param;

	/** Field paramPlusIV */
	private ParametersWithIV paramPlusIV;

	/** Field iv */
	private byte[] iv;

	/** Field forWrapping */
	private boolean forWrapping;

	/** Field IV2 */
	private static final byte[] IV2 = { (byte) 0x4a, (byte) 0xdd, (byte) 0xa2,
	(byte) 0x2c, (byte) 0x79, (byte) 0xe8,
	(byte) 0x21, (byte) 0x05 };

	//
	// checksum digest
	//
	// BEGIN android-changed
	Digest sha1 = AndroidDigestFactory.getSHA1();
	// END android-changed
	byte[] digest = new byte[20];

	/**
	* Method init
	*
	* @param forWrapping true if for wrapping, false otherwise.
	* @param param necessary parameters, may include KeyParameter, ParametersWithRandom, and ParametersWithIV
	*/
	public void init(boolean forWrapping, CipherParameters param)
	{

	this.forWrapping = forWrapping;
	this.engine = new CBCBlockCipher(new DESedeEngine());

	SecureRandom sr;
	if (param instanceof ParametersWithRandom)
	{
	ParametersWithRandom pr = (ParametersWithRandom) param;
	param = pr.getParameters();
	sr = pr.getRandom();
	}
	else
	{
	sr = new SecureRandom();
	}

	if (param instanceof KeyParameter)
	{
	this.param = (KeyParameter)param;

	if (this.forWrapping)
	{

	// Hm, we have no IV but we want to wrap ?!?
	// well, then we have to create our own IV.
	this.iv = new byte[8];
	sr.nextBytes(iv);

	this.paramPlusIV = new ParametersWithIV(this.param, this.iv);
	}
	}
	else if (param instanceof ParametersWithIV)
	{
	this.paramPlusIV = (ParametersWithIV)param;
	this.iv = this.paramPlusIV.getIV();
	this.param = (KeyParameter)this.paramPlusIV.getParameters();

	if (this.forWrapping)
	{
	if ((this.iv == null) \|\| (this.iv.length != 8))
	{
	throw new IllegalArgumentException("IV is not 8 octets");
	}
	}
	else
	{
	throw new IllegalArgumentException(
	"You should not supply an IV for unwrapping");
	}
	}
	}

	/**
	* Method getAlgorithmName
	*
	* @return the algorithm name "DESede".
	*/
	public String getAlgorithmName()
	{
	return "DESede";
	}

	/**
	* Method wrap
	*
	* @param in byte array containing the encoded key.
	* @param inOff off set into in that the data starts at.
	* @param inLen length of the data.
	* @return the wrapped bytes.
	*/
	public byte[] wrap(byte[] in, int inOff, int inLen)
	{
	if (!forWrapping)
	{
	throw new IllegalStateException("Not initialized for wrapping");
	}

	byte keyToBeWrapped[] = new byte[inLen];

	System.arraycopy(in, inOff, keyToBeWrapped, 0, inLen);

	// Compute the CMS Key Checksum, (section 5.6.1), call this CKS.
	byte[] CKS = calculateCMSKeyChecksum(keyToBeWrapped);

	// Let WKCKS = WK \|\| CKS where \|\| is concatenation.
	byte[] WKCKS = new byte[keyToBeWrapped.length + CKS.length];

	System.arraycopy(keyToBeWrapped, 0, WKCKS, 0, keyToBeWrapped.length);
	System.arraycopy(CKS, 0, WKCKS, keyToBeWrapped.length, CKS.length);

	// Encrypt WKCKS in CBC mode using KEK as the key and IV as the
	// initialization vector. Call the results TEMP1.

	int blockSize = engine.getBlockSize();

	if (WKCKS.length % blockSize != 0)
	{
	throw new IllegalStateException("Not multiple of block length");
	}

	engine.init(true, paramPlusIV);

	byte TEMP1[] = new byte[WKCKS.length];

	for (int currentBytePos = 0; currentBytePos != WKCKS.length; currentBytePos += blockSize)
	{
	engine.processBlock(WKCKS, currentBytePos, TEMP1, currentBytePos);
	}

	// Let TEMP2 = IV \|\| TEMP1.
	byte[] TEMP2 = new byte[this.iv.length + TEMP1.length];

	System.arraycopy(this.iv, 0, TEMP2, 0, this.iv.length);
	System.arraycopy(TEMP1, 0, TEMP2, this.iv.length, TEMP1.length);

	// Reverse the order of the octets in TEMP2 and call the result TEMP3.
	byte[] TEMP3 = reverse(TEMP2);

	// Encrypt TEMP3 in CBC mode using the KEK and an initialization vector
	// of 0x 4a dd a2 2c 79 e8 21 05. The resulting cipher text is the desired
	// result. It is 40 octets long if a 168 bit key is being wrapped.
	ParametersWithIV param2 = new ParametersWithIV(this.param, IV2);

	this.engine.init(true, param2);

	for (int currentBytePos = 0; currentBytePos != TEMP3.length; currentBytePos += blockSize)
	{
	engine.processBlock(TEMP3, currentBytePos, TEMP3, currentBytePos);
	}

	return TEMP3;
	}

	/**
	* Method unwrap
	*
	* @param in byte array containing the wrapped key.
	* @param inOff off set into in that the data starts at.
	* @param inLen length of the data.
	* @return the unwrapped bytes.
	* @throws InvalidCipherTextException
	*/
	public byte[] unwrap(byte[] in, int inOff, int inLen)
	throws InvalidCipherTextException
	{
	if (forWrapping)
	{
	throw new IllegalStateException("Not set for unwrapping");
	}

	if (in == null)
	{
	throw new InvalidCipherTextException("Null pointer as ciphertext");
	}

	final int blockSize = engine.getBlockSize();
	if (inLen % blockSize != 0)
	{
	throw new InvalidCipherTextException("Ciphertext not multiple of " + blockSize);
	}

	/*
	// Check if the length of the cipher text is reasonable given the key
	// type. It must be 40 bytes for a 168 bit key and either 32, 40, or
	// 48 bytes for a 128, 192, or 256 bit key. If the length is not supported
	// or inconsistent with the algorithm for which the key is intended,
	// return error.
	//
	// we do not accept 168 bit keys. it has to be 192 bit.
	int lengthA = (estimatedKeyLengthInBit / 8) + 16;
	int lengthB = estimatedKeyLengthInBit % 8;

	if ((lengthA != keyToBeUnwrapped.length) \|\| (lengthB != 0)) {
	throw new XMLSecurityException("empty");
	}
	*/

	// Decrypt the cipher text with TRIPLedeS in CBC mode using the KEK
	// and an initialization vector (IV) of 0x4adda22c79e82105. Call the output TEMP3.
	ParametersWithIV param2 = new ParametersWithIV(this.param, IV2);

	this.engine.init(false, param2);

	byte TEMP3[] = new byte[inLen];

	for (int currentBytePos = 0; currentBytePos != inLen; currentBytePos += blockSize)
	{
	engine.processBlock(in, inOff + currentBytePos, TEMP3, currentBytePos);
	}

	// Reverse the order of the octets in TEMP3 and call the result TEMP2.
	byte[] TEMP2 = reverse(TEMP3);

	// Decompose TEMP2 into IV, the first 8 octets, and TEMP1, the remaining octets.
	this.iv = new byte[8];

	byte[] TEMP1 = new byte[TEMP2.length - 8];

	System.arraycopy(TEMP2, 0, this.iv, 0, 8);
	System.arraycopy(TEMP2, 8, TEMP1, 0, TEMP2.length - 8);

	// Decrypt TEMP1 using TRIPLedeS in CBC mode using the KEK and the IV
	// found in the previous step. Call the result WKCKS.
	this.paramPlusIV = new ParametersWithIV(this.param, this.iv);

	this.engine.init(false, this.paramPlusIV);

	byte[] WKCKS = new byte[TEMP1.length];

	for (int currentBytePos = 0; currentBytePos != WKCKS.length; currentBytePos += blockSize)
	{
	engine.processBlock(TEMP1, currentBytePos, WKCKS, currentBytePos);
	}

	// Decompose WKCKS. CKS is the last 8 octets and WK, the wrapped key, are
	// those octets before the CKS.
	byte[] result = new byte[WKCKS.length - 8];
	byte[] CKStoBeVerified = new byte[8];

	System.arraycopy(WKCKS, 0, result, 0, WKCKS.length - 8);
	System.arraycopy(WKCKS, WKCKS.length - 8, CKStoBeVerified, 0, 8);

	// Calculate a CMS Key Checksum, (section 5.6.1), over the WK and compare
	// with the CKS extracted in the above step. If they are not equal, return error.
	if (!checkCMSKeyChecksum(result, CKStoBeVerified))
	{
	throw new InvalidCipherTextException(
	"Checksum inside ciphertext is corrupted");
	}

	// WK is the wrapped key, now extracted for use in data decryption.
	return result;
	}

	/**
	* Some key wrap algorithms make use of the Key Checksum defined
	* in CMS [CMS-Algorithms]. This is used to provide an integrity
	* check value for the key being wrapped. The algorithm is
	*
	* - Compute the 20 octet SHA-1 hash on the key being wrapped.
	* - Use the first 8 octets of this hash as the checksum value.
	*
	* For details see http://www.w3.org/TR/xmlenc-core/#sec-CMSKeyChecksum.
	*
	* @param key the key to check,
	* @return the CMS checksum.
	* @throws RuntimeException
	*/
	private byte[] calculateCMSKeyChecksum(
	byte[] key)
	{
	byte[] result = new byte[8];

	sha1.update(key, 0, key.length);
	sha1.doFinal(digest, 0);

	System.arraycopy(digest, 0, result, 0, 8);

	return result;
	}

	/**
	* For details see http://www.w3.org/TR/xmlenc-core/#sec-CMSKeyChecksum
	*
	* @param key key to be validated.
	* @param checksum the checksum.
	* @return true if okay, false otherwise.
	*/
	private boolean checkCMSKeyChecksum(
	byte[] key,
	byte[] checksum)
	{
	return Arrays.constantTimeAreEqual(calculateCMSKeyChecksum(key), checksum);
	}

	private static byte[] reverse(byte[] bs)
	{
	byte[] result = new byte[bs.length];
	for (int i = 0; i < bs.length; i++)
	{
	result[i] = bs[bs.length - (i + 1)];
	}
	return result;
	}
	}