1 files changed, 181 insertions, 0 deletions
diff --git a/pkix/src/main/java/org/spongycastle/cms/RecipientInformation.java b/pkix/src/main/java/org/spongycastle/cms/RecipientInformation.java
new file mode 100644
index 00000000..c083baa9
--- /dev/null
+++ b/pkix/src/main/java/org/spongycastle/cms/RecipientInformation.java
@@ -0,0 +1,181 @@
+package org.spongycastle.cms;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+
+import org.spongycastle.asn1.ASN1Encodable;
+import org.spongycastle.asn1.ASN1Encoding;
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.util.io.Streams;
+
+public abstract class RecipientInformation
+{
+    protected RecipientId rid;
+    protected AlgorithmIdentifier   keyEncAlg;
+    protected AlgorithmIdentifier messageAlgorithm;
+    protected CMSSecureReadable     secureReadable;
+
+    private AuthAttributesProvider additionalData;
+
+    private byte[] resultMac;
+    private RecipientOperator     operator;
+
+    RecipientInformation(
+        AlgorithmIdentifier     keyEncAlg,
+        AlgorithmIdentifier     messageAlgorithm,
+        CMSSecureReadable       secureReadable,
+        AuthAttributesProvider  additionalData)
+    {
+        this.keyEncAlg = keyEncAlg;
+        this.messageAlgorithm = messageAlgorithm;
+        this.secureReadable = secureReadable;
+        this.additionalData = additionalData;
+    }
+
+    public RecipientId getRID()
+    {
+        return rid;
+    }
+
+    private byte[] encodeObj(
+        ASN1Encodable obj)
+        throws IOException
+    {
+        if (obj != null)
+        {
+            return obj.toASN1Primitive().getEncoded();
+        }
+
+        return null;
+    }
+
+    /**
+     * Return the key encryption algorithm details for the key in this recipient.
+     *
+     * @return AlgorithmIdentifier representing the key encryption algorithm.
+     */
+    public AlgorithmIdentifier getKeyEncryptionAlgorithm()
+    {
+        return keyEncAlg;
+    }
+
+    /**
+     * return the object identifier for the key encryption algorithm.
+     *
+     * @return OID for key encryption algorithm.
+     */
+    public String getKeyEncryptionAlgOID()
+    {
+        return keyEncAlg.getAlgorithm().getId();
+    }
+
+    /**
+     * return the ASN.1 encoded key encryption algorithm parameters, or null if
+     * there aren't any.
+     *
+     * @return ASN.1 encoding of key encryption algorithm parameters.
+     */
+    public byte[] getKeyEncryptionAlgParams()
+    {
+        try
+        {
+            return encodeObj(keyEncAlg.getParameters());
+        }
+        catch (Exception e)
+        {
+            throw new RuntimeException("exception getting encryption parameters " + e);
+        }
+    }
+
+    /**
+     * Return the content digest calculated during the read of the content if one has been generated. This will
+     * only happen if we are dealing with authenticated data and authenticated attributes are present.
+     *
+     * @return byte array containing the digest.
+     */
+    public byte[] getContentDigest()
+    {
+        if (secureReadable instanceof CMSEnvelopedHelper.CMSDigestAuthenticatedSecureReadable)
+        {
+            return ((CMSEnvelopedHelper.CMSDigestAuthenticatedSecureReadable)secureReadable).getDigest();
+        }
+
+        return null;
+    }
+
+    /**
+     * Return the MAC calculated for the recipient. Note: this call is only meaningful once all
+     * the content has been read.
+     *
+     * @return  byte array containing the mac.
+     */
+    public byte[] getMac()
+    {
+        if (resultMac == null)
+        {
+            if (operator.isMacBased())
+            {
+                if (additionalData != null)
+                {
+                    try
+                    {
+                        Streams.drain(operator.getInputStream(new ByteArrayInputStream(additionalData.getAuthAttributes().getEncoded(ASN1Encoding.DER))));
+                    }
+                    catch (IOException e)
+                    {
+                        throw new IllegalStateException("unable to drain input: " + e.getMessage());
+                    }
+                }
+                resultMac = operator.getMac();
+            }
+        }
+
+        return resultMac;
+    }
+
+    /**
+     * Return the decrypted/encapsulated content in the EnvelopedData after recovering the content
+     * encryption/MAC key using the passed in Recipient.
+     *
+     * @param recipient recipient object to use to recover content encryption key
+     * @return  the content inside the EnvelopedData this RecipientInformation is associated with.
+     * @throws CMSException if the content-encryption/MAC key cannot be recovered.
+     */
+    public byte[] getContent(
+        Recipient recipient)
+        throws CMSException
+    {
+        try
+        {
+            return CMSUtils.streamToByteArray(getContentStream(recipient).getContentStream());
+        }
+        catch (IOException e)
+        {
+            throw new CMSException("unable to parse internal stream: " + e.getMessage(), e);
+        }
+    }
+
+    /**
+     * Return a CMSTypedStream representing the content in the EnvelopedData after recovering the content
+     * encryption/MAC key using the passed in Recipient.
+     *
+     * @param recipient recipient object to use to recover content encryption key
+     * @return  the content inside the EnvelopedData this RecipientInformation is associated with.
+     * @throws CMSException if the content-encryption/MAC key cannot be recovered.
+     */
+    public CMSTypedStream getContentStream(Recipient recipient)
+        throws CMSException, IOException
+    {
+        operator = getRecipientOperator(recipient);
+
+        if (additionalData != null)
+        {
+            return new CMSTypedStream(secureReadable.getInputStream());
+        }
+
+        return new CMSTypedStream(operator.getInputStream(secureReadable.getInputStream()));
+    }
+
+    protected abstract RecipientOperator getRecipientOperator(Recipient recipient)
+        throws CMSException, IOException;
+}