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author | Peter Dettman <peter.dettman@bouncycastle.org> | 2013-06-28 15:26:06 +0700 |
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committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2013-06-28 15:26:06 +0700 |
commit | 44288db4414158ac9b98a507b15e81d0d3c66ca6 (patch) | |
tree | aa5ef88948ebb68ed6c8df81eb5da889641a9b50 /crypto/src/cms/CMSEnvelopedDataParser.cs | |
parent | Set up text/binary handling for existing file types (diff) | |
download | BouncyCastle.NET-ed25519-44288db4414158ac9b98a507b15e81d0d3c66ca6.tar.xz |
Initial import of old CVS repository
Diffstat (limited to 'crypto/src/cms/CMSEnvelopedDataParser.cs')
-rw-r--r-- | crypto/src/cms/CMSEnvelopedDataParser.cs | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/crypto/src/cms/CMSEnvelopedDataParser.cs b/crypto/src/cms/CMSEnvelopedDataParser.cs new file mode 100644 index 000000000..01a949d47 --- /dev/null +++ b/crypto/src/cms/CMSEnvelopedDataParser.cs @@ -0,0 +1,161 @@ +using System; +using System.Collections; +using System.IO; + +using Org.BouncyCastle.Asn1; +using Org.BouncyCastle.Asn1.Cms; +using Org.BouncyCastle.Asn1.X509; +using Org.BouncyCastle.Crypto; + +namespace Org.BouncyCastle.Cms +{ + /** + * 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(privateKey); + * + * 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. + * </p> + */ + public class CmsEnvelopedDataParser + : CmsContentInfoParser + { + internal RecipientInformationStore recipientInfoStore; + internal EnvelopedDataParser envelopedData; + + private AlgorithmIdentifier _encAlg; + private Asn1.Cms.AttributeTable _unprotectedAttributes; + private bool _attrNotRead; + + public CmsEnvelopedDataParser( + byte[] envelopedData) + : this(new MemoryStream(envelopedData, false)) + { + } + + public CmsEnvelopedDataParser( + Stream envelopedData) + : base(envelopedData) + { + this._attrNotRead = true; + this.envelopedData = new EnvelopedDataParser( + (Asn1SequenceParser)this.contentInfo.GetContent(Asn1Tags.Sequence)); + + // TODO Validate version? + //DerInteger version = this.envelopedData.Version; + + // + // read the recipients + // + Asn1Set recipientInfos = Asn1Set.GetInstance(this.envelopedData.GetRecipientInfos().ToAsn1Object()); + + // + // read the encrypted content info + // + EncryptedContentInfoParser encInfo = this.envelopedData.GetEncryptedContentInfo(); + this._encAlg = encInfo.ContentEncryptionAlgorithm; + CmsReadable readable = new CmsProcessableInputStream( + ((Asn1OctetStringParser)encInfo.GetEncryptedContent(Asn1Tags.OctetString)).GetOctetStream()); + CmsSecureReadable secureReadable = new CmsEnvelopedHelper.CmsEnvelopedSecureReadable( + this._encAlg, readable); + + // + // build the RecipientInformationStore + // + this.recipientInfoStore = CmsEnvelopedHelper.BuildRecipientInformationStore( + recipientInfos, secureReadable); + } + + public AlgorithmIdentifier EncryptionAlgorithmID + { + get { return _encAlg; } + } + + /** + * return the object identifier for the content encryption algorithm. + */ + public string EncryptionAlgOid + { + get { return _encAlg.ObjectID.Id; } + } + + /** + * return the ASN.1 encoded encryption algorithm parameters, or null if + * there aren't any. + */ + public Asn1Object EncryptionAlgParams + { + get + { + Asn1Encodable ae = _encAlg.Parameters; + + return ae == null ? null : ae.ToAsn1Object(); + } + } + + /** + * return a store of the intended recipients for this message + */ + public RecipientInformationStore GetRecipientInfos() + { + return this.recipientInfoStore; + } + + /** + * return a table of the unprotected attributes indexed by + * the OID of the attribute. + * @throws IOException + */ + public Asn1.Cms.AttributeTable GetUnprotectedAttributes() + { + if (_unprotectedAttributes == null && _attrNotRead) + { + Asn1SetParser asn1Set = this.envelopedData.GetUnprotectedAttrs(); + + _attrNotRead = false; + + if (asn1Set != null) + { + Asn1EncodableVector v = new Asn1EncodableVector(); + IAsn1Convertible o; + + while ((o = asn1Set.ReadObject()) != null) + { + Asn1SequenceParser seq = (Asn1SequenceParser)o; + + v.Add(seq.ToAsn1Object()); + } + + _unprotectedAttributes = new Asn1.Cms.AttributeTable(new DerSet(v)); + } + } + + return _unprotectedAttributes; + } + } +} |