1 files changed, 131 insertions, 0 deletions
diff --git a/pkix/src/main/java/org/spongycastle/cms/KeyAgreeRecipientInformation.java b/pkix/src/main/java/org/spongycastle/cms/KeyAgreeRecipientInformation.java
new file mode 100644
index 00000000..c00dcdf3
--- /dev/null
+++ b/pkix/src/main/java/org/spongycastle/cms/KeyAgreeRecipientInformation.java
@@ -0,0 +1,131 @@
+package org.spongycastle.cms;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.spongycastle.asn1.ASN1OctetString;
+import org.spongycastle.asn1.ASN1Sequence;
+import org.spongycastle.asn1.cms.IssuerAndSerialNumber;
+import org.spongycastle.asn1.cms.KeyAgreeRecipientIdentifier;
+import org.spongycastle.asn1.cms.KeyAgreeRecipientInfo;
+import org.spongycastle.asn1.cms.OriginatorIdentifierOrKey;
+import org.spongycastle.asn1.cms.OriginatorPublicKey;
+import org.spongycastle.asn1.cms.RecipientEncryptedKey;
+import org.spongycastle.asn1.cms.RecipientKeyIdentifier;
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.asn1.x509.SubjectKeyIdentifier;
+import org.spongycastle.asn1.x509.SubjectPublicKeyInfo;
+
+/**
+ * the RecipientInfo class for a recipient who has been sent a message
+ * encrypted using key agreement.
+ */
+public class KeyAgreeRecipientInformation
+    extends RecipientInformation
+{
+    private KeyAgreeRecipientInfo info;
+    private ASN1OctetString       encryptedKey;
+
+    static void readRecipientInfo(List infos, KeyAgreeRecipientInfo info,
+        AlgorithmIdentifier messageAlgorithm, CMSSecureReadable secureReadable, AuthAttributesProvider additionalData)
+    {
+        ASN1Sequence s = info.getRecipientEncryptedKeys();
+
+        for (int i = 0; i < s.size(); ++i)
+        {
+            RecipientEncryptedKey id = RecipientEncryptedKey.getInstance(
+                s.getObjectAt(i));
+
+            RecipientId rid;
+
+            KeyAgreeRecipientIdentifier karid = id.getIdentifier();
+            IssuerAndSerialNumber iAndSN = karid.getIssuerAndSerialNumber();
+
+            if (iAndSN != null)
+            {
+                rid = new KeyAgreeRecipientId(iAndSN.getName(), iAndSN.getSerialNumber().getValue());
+            }
+            else
+            {
+                RecipientKeyIdentifier rKeyID = karid.getRKeyID();
+
+                // Note: 'date' and 'other' fields of RecipientKeyIdentifier appear to be only informational
+
+                rid = new KeyAgreeRecipientId(rKeyID.getSubjectKeyIdentifier().getOctets());
+            }
+
+            infos.add(new KeyAgreeRecipientInformation(info, rid, id.getEncryptedKey(), messageAlgorithm,
+                secureReadable, additionalData));
+        }
+    }
+
+    KeyAgreeRecipientInformation(
+        KeyAgreeRecipientInfo   info,
+        RecipientId             rid,
+        ASN1OctetString         encryptedKey,
+        AlgorithmIdentifier     messageAlgorithm,
+        CMSSecureReadable       secureReadable,
+        AuthAttributesProvider  additionalData)
+    {
+        super(info.getKeyEncryptionAlgorithm(), messageAlgorithm, secureReadable, additionalData);
+
+        this.info = info;
+        this.rid = rid;
+        this.encryptedKey = encryptedKey;
+    }
+
+    private SubjectPublicKeyInfo getSenderPublicKeyInfo(AlgorithmIdentifier recKeyAlgId,
+        OriginatorIdentifierOrKey originator)
+        throws CMSException, IOException
+    {
+        OriginatorPublicKey opk = originator.getOriginatorKey();
+        if (opk != null)
+        {
+            return getPublicKeyInfoFromOriginatorPublicKey(recKeyAlgId, opk);
+        }
+
+        OriginatorId origID;
+
+        IssuerAndSerialNumber iAndSN = originator.getIssuerAndSerialNumber();
+        if (iAndSN != null)
+        {
+            origID = new OriginatorId(iAndSN.getName(), iAndSN.getSerialNumber().getValue());
+        }
+        else
+        {
+            SubjectKeyIdentifier ski = originator.getSubjectKeyIdentifier();
+
+            origID = new OriginatorId(ski.getKeyIdentifier());
+        }
+
+        return getPublicKeyInfoFromOriginatorId(origID);
+    }
+
+    private SubjectPublicKeyInfo getPublicKeyInfoFromOriginatorPublicKey(AlgorithmIdentifier recKeyAlgId,
+            OriginatorPublicKey originatorPublicKey)
+    {
+        SubjectPublicKeyInfo pubInfo = new SubjectPublicKeyInfo(
+            recKeyAlgId,
+            originatorPublicKey.getPublicKey().getBytes());
+
+        return pubInfo;
+    }
+
+    private SubjectPublicKeyInfo getPublicKeyInfoFromOriginatorId(OriginatorId origID)
+            throws CMSException
+    {
+        // TODO Support all alternatives for OriginatorIdentifierOrKey
+        // see RFC 3852 6.2.2
+        throw new CMSException("No support for 'originator' as IssuerAndSerialNumber or SubjectKeyIdentifier");
+    }
+
+    protected RecipientOperator getRecipientOperator(Recipient recipient)
+        throws CMSException, IOException
+    {
+        KeyAgreeRecipient agreeRecipient = (KeyAgreeRecipient)recipient;
+                AlgorithmIdentifier    recKeyAlgId = agreeRecipient.getPrivateKeyAlgorithmIdentifier();
+
+        return ((KeyAgreeRecipient)recipient).getRecipientOperator(keyEncAlg, messageAlgorithm, getSenderPublicKeyInfo(recKeyAlgId,
+                        info.getOriginator()), info.getUserKeyingMaterial(), encryptedKey.getOctets());
+    }
+}