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Diffstat (limited to 'pkix/src/main/java/org/spongycastle/cms/CMSEnvelopedDataParser.java')
| -rw-r--r-- | pkix/src/main/java/org/spongycastle/cms/CMSEnvelopedDataParser.java | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/pkix/src/main/java/org/spongycastle/cms/CMSEnvelopedDataParser.java b/pkix/src/main/java/org/spongycastle/cms/CMSEnvelopedDataParser.java new file mode 100644 index 00000000..ae821a6a --- /dev/null +++ b/pkix/src/main/java/org/spongycastle/cms/CMSEnvelopedDataParser.java @@ -0,0 +1,208 @@ +package org.spongycastle.cms; + +import java.io.ByteArrayInputStream; +import java.io.IOException; +import java.io.InputStream; + +import org.spongycastle.asn1.ASN1Encodable; +import org.spongycastle.asn1.ASN1EncodableVector; +import org.spongycastle.asn1.ASN1OctetStringParser; +import org.spongycastle.asn1.ASN1SequenceParser; +import org.spongycastle.asn1.ASN1Set; +import org.spongycastle.asn1.ASN1SetParser; +import org.spongycastle.asn1.BERTags; +import org.spongycastle.asn1.DERSet; +import org.spongycastle.asn1.cms.AttributeTable; +import org.spongycastle.asn1.cms.EncryptedContentInfoParser; +import org.spongycastle.asn1.cms.EnvelopedDataParser; +import org.spongycastle.asn1.cms.OriginatorInfo; +import org.spongycastle.asn1.x509.AlgorithmIdentifier; + +/** + * Parsing class for an CMS Enveloped Data object from an input stream. + * <p> + * Note: that because we are in a streaming mode only one recipient can be tried and it is important + * that the methods on the parser are called in the appropriate order. + * </p> + * <p> + * Example of use - assuming the first recipient matches the private key we have. + * <pre> + * CMSEnvelopedDataParser ep = new CMSEnvelopedDataParser(inputStream); + * + * RecipientInformationStore recipients = ep.getRecipientInfos(); + * + * Collection c = recipients.getRecipients(); + * Iterator it = c.iterator(); + * + * if (it.hasNext()) + * { + * RecipientInformation recipient = (RecipientInformation)it.next(); + * + * CMSTypedStream recData = recipient.getContentStream(new JceKeyTransEnvelopedRecipient(privateKey).setProvider("SC")); + * + * processDataStream(recData.getContentStream()); + * } + * </pre> + * Note: this class does not introduce buffering - if you are processing large files you should create + * the parser with: + * <pre> + * CMSEnvelopedDataParser ep = new CMSEnvelopedDataParser(new BufferedInputStream(inputStream, bufSize)); + * </pre> + * where bufSize is a suitably large buffer size. + */ +public class CMSEnvelopedDataParser + extends CMSContentInfoParser +{ + RecipientInformationStore recipientInfoStore; + EnvelopedDataParser envelopedData; + + private AlgorithmIdentifier encAlg; + private AttributeTable unprotectedAttributes; + private boolean attrNotRead; + private OriginatorInformation originatorInfo; + + public CMSEnvelopedDataParser( + byte[] envelopedData) + throws CMSException, IOException + { + this(new ByteArrayInputStream(envelopedData)); + } + + public CMSEnvelopedDataParser( + InputStream envelopedData) + throws CMSException, IOException + { + super(envelopedData); + + this.attrNotRead = true; + this.envelopedData = new EnvelopedDataParser((ASN1SequenceParser)_contentInfo.getContent(BERTags.SEQUENCE)); + + // TODO Validate version? + //ASN1Integer version = this._envelopedData.getVersion(); + + OriginatorInfo info = this.envelopedData.getOriginatorInfo(); + + if (info != null) + { + this.originatorInfo = new OriginatorInformation(info); + } + + // + // read the recipients + // + ASN1Set recipientInfos = ASN1Set.getInstance(this.envelopedData.getRecipientInfos().toASN1Primitive()); + + // + // read the encrypted content info + // + EncryptedContentInfoParser encInfo = this.envelopedData.getEncryptedContentInfo(); + this.encAlg = encInfo.getContentEncryptionAlgorithm(); + CMSReadable readable = new CMSProcessableInputStream( + ((ASN1OctetStringParser)encInfo.getEncryptedContent(BERTags.OCTET_STRING)).getOctetStream()); + CMSSecureReadable secureReadable = new CMSEnvelopedHelper.CMSEnvelopedSecureReadable( + this.encAlg, readable); + + // + // build the RecipientInformationStore + // + this.recipientInfoStore = CMSEnvelopedHelper.buildRecipientInformationStore( + recipientInfos, this.encAlg, secureReadable); + } + + /** + * return the object identifier for the content encryption algorithm. + */ + public String getEncryptionAlgOID() + { + return encAlg.getAlgorithm().toString(); + } + + /** + * return the ASN.1 encoded encryption algorithm parameters, or null if + * there aren't any. + */ + public byte[] getEncryptionAlgParams() + { + try + { + return encodeObj(encAlg.getParameters()); + } + catch (Exception e) + { + throw new RuntimeException("exception getting encryption parameters " + e); + } + } + + /** + * Return the content encryption algorithm details for the data in this object. + * + * @return AlgorithmIdentifier representing the content encryption algorithm. + */ + public AlgorithmIdentifier getContentEncryptionAlgorithm() + { + return encAlg; + } + + /** + * Return the originator information associated with this message if present. + * + * @return OriginatorInformation, null if not present. + */ + public OriginatorInformation getOriginatorInfo() + { + return originatorInfo; + } + + /** + * return a store of the intended recipients for this message + */ + public RecipientInformationStore getRecipientInfos() + { + return recipientInfoStore; + } + + /** + * return a table of the unprotected attributes indexed by + * the OID of the attribute. + * @exception IOException + */ + public AttributeTable getUnprotectedAttributes() + throws IOException + { + if (unprotectedAttributes == null && attrNotRead) + { + ASN1SetParser set = envelopedData.getUnprotectedAttrs(); + + attrNotRead = false; + + if (set != null) + { + ASN1EncodableVector v = new ASN1EncodableVector(); + ASN1Encodable o; + + while ((o = set.readObject()) != null) + { + ASN1SequenceParser seq = (ASN1SequenceParser)o; + + v.add(seq.toASN1Primitive()); + } + + unprotectedAttributes = new AttributeTable(new DERSet(v)); + } + } + + return unprotectedAttributes; + } + + private byte[] encodeObj( + ASN1Encodable obj) + throws IOException + { + if (obj != null) + { + return obj.toASN1Primitive().getEncoded(); + } + + return null; + } +} |