public CmsEnvelopedDataOutputStream( CmsEnvelopedGenerator outer, CipherStream outStream, BerSequenceGenerator cGen, BerSequenceGenerator envGen, BerSequenceGenerator eiGen) { _outer = outer; _out = outStream; _cGen = cGen; _envGen = envGen; _eiGen = eiGen; }
private Stream Open( Stream outStream, AlgorithmIdentifier encAlgID, ICipherParameters cipherParameters, Asn1EncodableVector recipientInfos) { try { // // ContentInfo // BerSequenceGenerator cGen = new BerSequenceGenerator(outStream); cGen.AddObject(CmsObjectIdentifiers.EnvelopedData); // // Encrypted Data // BerSequenceGenerator envGen = new BerSequenceGenerator( cGen.GetRawOutputStream(), 0, true); envGen.AddObject(this.Version); Stream envRaw = envGen.GetRawOutputStream(); Asn1Generator recipGen = _berEncodeRecipientSet ? (Asn1Generator) new BerSetGenerator(envRaw) : new DerSetGenerator(envRaw); foreach (Asn1Encodable ae in recipientInfos) { recipGen.AddObject(ae); } recipGen.Close(); BerSequenceGenerator eiGen = new BerSequenceGenerator(envRaw); eiGen.AddObject(CmsObjectIdentifiers.Data); eiGen.AddObject(encAlgID); Stream octetOutputStream = CmsUtilities.CreateBerOctetOutputStream( eiGen.GetRawOutputStream(), 0, false, _bufferSize); IBufferedCipher cipher = CipherUtilities.GetCipher(encAlgID.ObjectID); cipher.Init(true, new ParametersWithRandom(cipherParameters, rand)); CipherStream cOut = new CipherStream(octetOutputStream, null, cipher); return new CmsEnvelopedDataOutputStream(this, cOut, cGen, envGen, eiGen); } catch (SecurityUtilityException e) { throw new CmsException("couldn't create cipher.", e); } catch (InvalidKeyException e) { throw new CmsException("key invalid in message.", e); } catch (IOException e) { throw new CmsException("exception decoding algorithm parameters.", e); } }
/// <summary> /// <p> /// Close off the encrypted object - this is equivalent to calling Close() on the stream /// returned by the Open() method. /// </p> /// <p> /// <b>Note</b>: This does not close the underlying output stream, only the stream on top of /// it created by the Open() method. /// </p> /// </summary> public void Close() { if (cOut != null) { // TODO Should this all be under the try/catch block? if (digestOut != null) { // // hand code a mod detection packet // BcpgOutputStream bOut = new BcpgOutputStream( digestOut, PacketTag.ModificationDetectionCode, 20); bOut.Flush(); digestOut.Flush(); // TODO byte[] dig = DigestUtilities.DoFinal(digestOut.WriteDigest()); cOut.Write(dig, 0, dig.Length); } cOut.Flush(); try { pOut.Write(c.DoFinal()); pOut.Finish(); } catch (Exception e) { throw new IOException(e.Message, e); } cOut = null; pOut = null; } }
/// <summary> /// Generate an enveloped object that contains a CMS Enveloped Data /// object using the passed in key generator. /// </summary> private CmsEnvelopedData Generate( CmsProcessable content, string encryptionOid, CipherKeyGenerator keyGen) { AlgorithmIdentifier encAlgId = null; KeyParameter encKey; Asn1OctetString encContent; try { byte[] encKeyBytes = keyGen.GenerateKey(); encKey = ParameterUtilities.CreateKeyParameter(encryptionOid, encKeyBytes); Asn1Encodable asn1Params = GenerateAsn1Parameters(encryptionOid, encKeyBytes); ICipherParameters cipherParameters; encAlgId = GetAlgorithmIdentifier( encryptionOid, encKey, asn1Params, out cipherParameters); IBufferedCipher cipher = CipherUtilities.GetCipher(encryptionOid); cipher.Init(true, new ParametersWithRandom(cipherParameters, rand)); MemoryStream bOut = new MemoryStream(); CipherStream cOut = new CipherStream(bOut, null, cipher); content.Write(cOut); cOut.Dispose(); encContent = new BerOctetString(bOut.ToArray()); } catch (SecurityUtilityException e) { throw new CmsException("couldn't create cipher.", e); } catch (InvalidKeyException e) { throw new CmsException("key invalid in message.", e); } catch (IOException e) { throw new CmsException("exception decoding algorithm parameters.", e); } Asn1EncodableVector recipientInfos = new Asn1EncodableVector(); foreach (RecipientInfoGenerator rig in recipientInfoGenerators) { try { recipientInfos.Add(rig.Generate(encKey, rand)); } catch (InvalidKeyException e) { throw new CmsException("key inappropriate for algorithm.", e); } catch (GeneralSecurityException e) { throw new CmsException("error making encrypted content.", e); } } EncryptedContentInfo eci = new EncryptedContentInfo( CmsObjectIdentifiers.Data, encAlgId, encContent); Asn1Set unprotectedAttrSet = null; if (unprotectedAttributeGenerator != null) { Asn1.Cms.AttributeTable attrTable = unprotectedAttributeGenerator.GetAttributes(Platform.CreateHashtable()); unprotectedAttrSet = new BerSet(attrTable.ToAsn1EncodableVector()); } ContentInfo contentInfo = new ContentInfo( CmsObjectIdentifiers.EnvelopedData, new EnvelopedData(null, new DerSet(recipientInfos), eci, unprotectedAttrSet)); return new CmsEnvelopedData(contentInfo); }
/// <summary> /// <p> /// If buffer is non null stream assumed to be partial, otherwise the length will be used /// to output a fixed length packet. /// </p> /// <p> /// The stream created can be closed off by either calling Close() /// on the stream or Close() on the generator. Closing the returned /// stream does not close off the Stream parameter <c>outStr</c>. /// </p> /// </summary> private Stream Open( Stream outStr, long length, byte[] buffer) { if (cOut != null) throw new InvalidOperationException("generator already in open state"); if (methods.Count == 0) throw new InvalidOperationException("No encryption methods specified"); if (outStr == null) throw new ArgumentNullException("outStr"); pOut = new BcpgOutputStream(outStr); KeyParameter key; if (methods.Count == 1) { if (methods[0] is PbeMethod) { PbeMethod m = (PbeMethod)methods[0]; key = m.GetKey(); } else { key = PgpUtilities.MakeRandomKey(defAlgorithm, rand); byte[] sessionInfo = CreateSessionInfo(defAlgorithm, key); PubMethod m = (PubMethod)methods[0]; try { m.AddSessionInfo(sessionInfo, rand); } catch (Exception e) { throw new PgpException("exception encrypting session key", e); } } pOut.WritePacket((ContainedPacket)methods[0]); } else // multiple methods { key = PgpUtilities.MakeRandomKey(defAlgorithm, rand); byte[] sessionInfo = CreateSessionInfo(defAlgorithm, key); for (int i = 0; i != methods.Count; i++) { EncMethod m = (EncMethod)methods[i]; try { m.AddSessionInfo(sessionInfo, rand); } catch (Exception e) { throw new PgpException("exception encrypting session key", e); } pOut.WritePacket(m); } } string cName = PgpUtilities.GetSymmetricCipherName(defAlgorithm); if (cName == null) { throw new PgpException("null cipher specified"); } try { if (withIntegrityPacket) { cName += "/CFB/NoPadding"; } else { cName += "/OpenPGPCFB/NoPadding"; } c = CipherUtilities.GetCipher(cName); // TODO Confirm the IV should be all zero bytes (not inLineIv - see below) byte[] iv = new byte[c.GetBlockSize()]; c.Init(true, new ParametersWithRandom(new ParametersWithIV(key, iv), rand)); if (buffer == null) { // // we have to Add block size + 2 for the Generated IV and + 1 + 22 if integrity protected // if (withIntegrityPacket) { pOut = new BcpgOutputStream(outStr, PacketTag.SymmetricEncryptedIntegrityProtected, length + c.GetBlockSize() + 2 + 1 + 22); pOut.WriteByte(1); // version number } else { pOut = new BcpgOutputStream(outStr, PacketTag.SymmetricKeyEncrypted, length + c.GetBlockSize() + 2, oldFormat); } } else { if (withIntegrityPacket) { pOut = new BcpgOutputStream(outStr, PacketTag.SymmetricEncryptedIntegrityProtected, buffer); pOut.WriteByte(1); // version number } else { pOut = new BcpgOutputStream(outStr, PacketTag.SymmetricKeyEncrypted, buffer); } } int blockSize = c.GetBlockSize(); byte[] inLineIv = new byte[blockSize + 2]; rand.NextBytes(inLineIv, 0, blockSize); Array.Copy(inLineIv, inLineIv.Length - 4, inLineIv, inLineIv.Length - 2, 2); Stream myOut = cOut = new CipherStream(pOut, null, c); if (withIntegrityPacket) { string digestName = PgpUtilities.GetDigestName(HashAlgorithmTag.Sha1); IDigest digest = DigestUtilities.GetDigest(digestName); myOut = digestOut = new DigestStream(myOut, null, digest); } myOut.Write(inLineIv, 0, inLineIv.Length); return new WrappedGeneratorStream(this, myOut); } catch (Exception e) { throw new PgpException("Exception creating cipher", e); } }