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Viewing changes to src/org/bouncycastle/cms/KEKRecipientInformation.java

  • Committer: Brian Thomason
  • Date: 2011-12-20 17:20:32 UTC
  • Revision ID: brian.thomason@canonical.com-20111220172032-rdtm13jgdxtksacr
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src/org/bouncycastle/cms/KEKRecipientInformation.java
 
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package org.bouncycastle.cms;
 
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import java.io.IOException;
 
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import java.security.InvalidKeyException;
 
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import java.security.Key;
 
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import java.security.NoSuchAlgorithmException;
 
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import java.security.NoSuchProviderException;
 
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import java.security.Provider;
 
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import javax.crypto.Cipher;
 
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import javax.crypto.NoSuchPaddingException;
 
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import org.bouncycastle.asn1.cms.KEKIdentifier;
 
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import org.bouncycastle.asn1.cms.KEKRecipientInfo;
 
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import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
 
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/**
 
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 * the RecipientInfo class for a recipient who has been sent a message
 
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 * encrypted using a secret key known to the other side.
 
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 */
 
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public class KEKRecipientInformation
 
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    extends RecipientInformation
 
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{
 
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    private KEKRecipientInfo      info;
 
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    KEKRecipientInformation(
 
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        KEKRecipientInfo        info,
 
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        AlgorithmIdentifier     messageAlgorithm,
 
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        CMSSecureReadable       secureReadable,
 
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        AuthAttributesProvider  additionalData)
 
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    {
 
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        super(info.getKeyEncryptionAlgorithm(), messageAlgorithm, secureReadable, additionalData);
 
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        this.info = info;
 
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        KEKIdentifier kekId = info.getKekid();
 
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        this.rid = new KEKRecipientId(kekId.getKeyIdentifier().getOctets());
 
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    }
 
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    /**
 
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     * decrypt the content and return an input stream.
 
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     */
 
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    public CMSTypedStream getContentStream(
 
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        Key      key,
 
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        String   prov)
 
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        throws CMSException, NoSuchProviderException
 
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    {
 
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        return getContentStream(key, CMSUtils.getProvider(prov));
 
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    }
 
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    /**
 
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     * decrypt the content and return an input stream.
 
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     */
 
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    public CMSTypedStream getContentStream(
 
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        Key      key,
 
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        Provider prov)
 
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        throws CMSException
 
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    {
 
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        try
 
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        {
 
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            Cipher keyCipher = CMSEnvelopedHelper.INSTANCE.createSymmetricCipher(
 
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                keyEncAlg.getObjectId().getId(), prov);
 
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            keyCipher.init(Cipher.UNWRAP_MODE, key);
 
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            Key sKey = keyCipher.unwrap(info.getEncryptedKey().getOctets(), getContentAlgorithmName(),
 
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                Cipher.SECRET_KEY);
 
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            return getContentFromSessionKey(sKey, prov);
 
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        }
 
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        catch (NoSuchAlgorithmException e)
 
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        {
 
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            throw new CMSException("can't find algorithm.", e);
 
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        }
 
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        catch (InvalidKeyException e)
 
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        {
 
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            throw new CMSException("key invalid in message.", e);
 
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        }
 
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        catch (NoSuchPaddingException e)
 
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        {
 
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            throw new CMSException("required padding not supported.", e);
 
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        }
 
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    }
 
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    protected RecipientOperator getRecipientOperator(Recipient recipient)
 
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        throws CMSException, IOException
 
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    {
 
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        return ((KEKRecipient)recipient).getRecipientOperator(keyEncAlg, messageAlgorithm, info.getEncryptedKey().getOctets());
 
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    }
 
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}