1 files changed, 256 insertions, 0 deletions
diff --git a/pkix/src/main/java/org/spongycastle/tsp/cms/TimeStampDataUtil.java b/pkix/src/main/java/org/spongycastle/tsp/cms/TimeStampDataUtil.java
new file mode 100644
index 00000000..fd1bcc8d
--- /dev/null
+++ b/pkix/src/main/java/org/spongycastle/tsp/cms/TimeStampDataUtil.java
@@ -0,0 +1,256 @@
+package org.spongycastle.tsp.cms;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.spongycastle.asn1.ASN1Encoding;
+import org.spongycastle.asn1.ASN1ObjectIdentifier;
+import org.spongycastle.asn1.cms.AttributeTable;
+import org.spongycastle.asn1.cms.ContentInfo;
+import org.spongycastle.asn1.cms.Evidence;
+import org.spongycastle.asn1.cms.TimeStampAndCRL;
+import org.spongycastle.asn1.cms.TimeStampedData;
+import org.spongycastle.asn1.cms.TimeStampedDataParser;
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.cms.CMSException;
+import org.spongycastle.operator.DigestCalculator;
+import org.spongycastle.operator.DigestCalculatorProvider;
+import org.spongycastle.operator.OperatorCreationException;
+import org.spongycastle.tsp.TSPException;
+import org.spongycastle.tsp.TimeStampToken;
+import org.spongycastle.tsp.TimeStampTokenInfo;
+import org.spongycastle.util.Arrays;
+
+class TimeStampDataUtil
+{
+    private final TimeStampAndCRL[] timeStamps;
+
+    private final MetaDataUtil      metaDataUtil;
+
+    TimeStampDataUtil(TimeStampedData timeStampedData)
+    {
+        this.metaDataUtil = new MetaDataUtil(timeStampedData.getMetaData());
+
+        Evidence evidence = timeStampedData.getTemporalEvidence();
+        this.timeStamps = evidence.getTstEvidence().toTimeStampAndCRLArray();
+    }
+
+    TimeStampDataUtil(TimeStampedDataParser timeStampedData)
+        throws IOException
+    {       
+        this.metaDataUtil = new MetaDataUtil(timeStampedData.getMetaData());
+
+        Evidence evidence = timeStampedData.getTemporalEvidence();
+        this.timeStamps = evidence.getTstEvidence().toTimeStampAndCRLArray();
+    }
+
+    TimeStampToken getTimeStampToken(TimeStampAndCRL timeStampAndCRL)
+        throws CMSException
+    {
+        ContentInfo timeStampToken = timeStampAndCRL.getTimeStampToken();
+
+        try
+        {
+            TimeStampToken token = new TimeStampToken(timeStampToken);
+            return token;
+        }
+        catch (IOException e)
+        {
+            throw new CMSException("unable to parse token data: " + e.getMessage(), e);
+        }
+        catch (TSPException e)
+        {
+            if (e.getCause() instanceof CMSException)
+            {
+                throw (CMSException)e.getCause();
+            }
+
+            throw new CMSException("token data invalid: " + e.getMessage(), e);
+        }
+        catch (IllegalArgumentException e)
+        {
+            throw new CMSException("token data invalid: " + e.getMessage(), e);
+        }
+    }
+
+    void initialiseMessageImprintDigestCalculator(DigestCalculator calculator)
+        throws CMSException
+    {
+        metaDataUtil.initialiseMessageImprintDigestCalculator(calculator);
+    }
+
+    DigestCalculator getMessageImprintDigestCalculator(DigestCalculatorProvider calculatorProvider)
+        throws OperatorCreationException
+    {
+        TimeStampToken token;
+
+        try
+        {
+            token = this.getTimeStampToken(timeStamps[0]);
+
+            TimeStampTokenInfo info = token.getTimeStampInfo();
+            ASN1ObjectIdentifier algOID = info.getMessageImprintAlgOID();
+
+            DigestCalculator calc = calculatorProvider.get(new AlgorithmIdentifier(algOID));
+
+            initialiseMessageImprintDigestCalculator(calc);
+
+            return calc;
+        }
+        catch (CMSException e)
+        {
+            throw new OperatorCreationException("unable to extract algorithm ID: " + e.getMessage(), e);
+        }
+    }
+
+    TimeStampToken[] getTimeStampTokens()
+        throws CMSException
+    {
+        TimeStampToken[] tokens = new TimeStampToken[timeStamps.length];
+        for (int i = 0; i < timeStamps.length; i++)
+        {
+            tokens[i] = this.getTimeStampToken(timeStamps[i]);
+        }
+
+        return tokens;
+    }
+
+    TimeStampAndCRL[] getTimeStamps()
+    {
+        return timeStamps;
+    }
+
+    byte[] calculateNextHash(DigestCalculator calculator)
+        throws CMSException
+    {
+        TimeStampAndCRL tspToken = timeStamps[timeStamps.length - 1];
+
+        OutputStream out = calculator.getOutputStream();
+
+        try
+        {
+            out.write(tspToken.getEncoded(ASN1Encoding.DER));
+
+            out.close();
+
+            return calculator.getDigest();
+        }
+        catch (IOException e)
+        {
+            throw new CMSException("exception calculating hash: " + e.getMessage(), e);
+        }
+    }
+
+    /**
+     * Validate the digests present in the TimeStampTokens contained in the CMSTimeStampedData.
+     */
+    void validate(DigestCalculatorProvider calculatorProvider, byte[] dataDigest)
+        throws ImprintDigestInvalidException, CMSException
+    {
+        byte[] currentDigest = dataDigest;
+
+        for (int i = 0; i < timeStamps.length; i++)
+        {
+            try
+            {
+                TimeStampToken token = this.getTimeStampToken(timeStamps[i]);
+                if (i > 0)
+                {
+                    TimeStampTokenInfo info = token.getTimeStampInfo();
+                    DigestCalculator calculator = calculatorProvider.get(info.getHashAlgorithm());
+
+                    calculator.getOutputStream().write(timeStamps[i - 1].getEncoded(ASN1Encoding.DER));
+
+                    currentDigest = calculator.getDigest();
+                }
+
+                this.compareDigest(token, currentDigest);
+            }
+            catch (IOException e)
+            {
+                throw new CMSException("exception calculating hash: " + e.getMessage(), e);
+            }
+            catch (OperatorCreationException e)
+            {
+                throw new CMSException("cannot create digest: " + e.getMessage(), e);
+            }
+        }
+    }
+
+    void validate(DigestCalculatorProvider calculatorProvider, byte[] dataDigest, TimeStampToken timeStampToken)
+        throws ImprintDigestInvalidException, CMSException
+    {
+        byte[] currentDigest = dataDigest;
+        byte[] encToken;
+
+        try
+        {
+            encToken = timeStampToken.getEncoded();
+        }
+        catch (IOException e)
+        {
+            throw new CMSException("exception encoding timeStampToken: " + e.getMessage(), e);
+        }
+
+        for (int i = 0; i < timeStamps.length; i++)
+        {
+            try
+            {
+                TimeStampToken token = this.getTimeStampToken(timeStamps[i]);
+                if (i > 0)
+                {
+                    TimeStampTokenInfo info = token.getTimeStampInfo();
+                    DigestCalculator calculator = calculatorProvider.get(info.getHashAlgorithm());
+
+                    calculator.getOutputStream().write(timeStamps[i - 1].getEncoded(ASN1Encoding.DER));
+
+                    currentDigest = calculator.getDigest();
+                }
+
+                this.compareDigest(token, currentDigest);
+
+                if (Arrays.areEqual(token.getEncoded(), encToken))
+                {
+                    return;
+                }
+            }
+            catch (IOException e)
+            {
+                throw new CMSException("exception calculating hash: " + e.getMessage(), e);
+            }
+            catch (OperatorCreationException e)
+            {
+                throw new CMSException("cannot create digest: " + e.getMessage(), e);
+            }
+        }
+
+        throw new ImprintDigestInvalidException("passed in token not associated with timestamps present", timeStampToken);
+    }
+
+    private void compareDigest(TimeStampToken timeStampToken, byte[] digest)
+        throws ImprintDigestInvalidException
+    {
+        TimeStampTokenInfo info = timeStampToken.getTimeStampInfo();
+        byte[] tsrMessageDigest = info.getMessageImprintDigest();
+
+        if (!Arrays.areEqual(digest, tsrMessageDigest))
+        {
+            throw new ImprintDigestInvalidException("hash calculated is different from MessageImprintDigest found in TimeStampToken", timeStampToken);
+        }
+    }
+
+    String getFileName()
+    {
+        return metaDataUtil.getFileName();
+    }
+
+    String getMediaType()
+    {
+        return metaDataUtil.getMediaType();
+    }
+
+    AttributeTable getOtherMetaData()
+    {
+        return new AttributeTable(metaDataUtil.getOtherMetaData());
+    }
+}