diff options
Diffstat (limited to 'crypto/src/cms/CMSAuthenticatedDataStreamGenerator.cs')
| -rw-r--r-- | crypto/src/cms/CMSAuthenticatedDataStreamGenerator.cs | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/crypto/src/cms/CMSAuthenticatedDataStreamGenerator.cs b/crypto/src/cms/CMSAuthenticatedDataStreamGenerator.cs new file mode 100644 index 000000000..2603cb380 --- /dev/null +++ b/crypto/src/cms/CMSAuthenticatedDataStreamGenerator.cs @@ -0,0 +1,272 @@ +using System; +using System.IO; + +using Org.BouncyCastle.Asn1; +using Org.BouncyCastle.Asn1.Cms; +using Org.BouncyCastle.Asn1.X509; +using Org.BouncyCastle.Crypto; +using Org.BouncyCastle.Crypto.Generators; +using Org.BouncyCastle.Crypto.IO; +using Org.BouncyCastle.Crypto.Parameters; +using Org.BouncyCastle.Security; +using Org.BouncyCastle.Utilities.IO; + +namespace Org.BouncyCastle.Cms +{ + /** + * General class for generating a CMS authenticated-data message stream. + * <p> + * A simple example of usage. + * <pre> + * CMSAuthenticatedDataStreamGenerator edGen = new CMSAuthenticatedDataStreamGenerator(); + * + * edGen.addKeyTransRecipient(cert); + * + * ByteArrayOutputStream bOut = new ByteArrayOutputStream(); + * + * OutputStream out = edGen.open( + * bOut, CMSAuthenticatedDataGenerator.AES128_CBC, "BC");* + * out.write(data); + * + * out.close(); + * </pre> + * </p> + */ + public class CmsAuthenticatedDataStreamGenerator + : CmsAuthenticatedGenerator + { + // TODO Add support +// private object _originatorInfo = null; +// private object _unprotectedAttributes = null; + private int _bufferSize; + private bool _berEncodeRecipientSet; + + /** + * base constructor + */ + public CmsAuthenticatedDataStreamGenerator() + { + } + + /** + * constructor allowing specific source of randomness + * @param rand instance of SecureRandom to use + */ + public CmsAuthenticatedDataStreamGenerator( + SecureRandom rand) + : base(rand) + { + } + + /** + * Set the underlying string size for encapsulated data + * + * @param bufferSize length of octet strings to buffer the data. + */ + public void SetBufferSize( + int bufferSize) + { + _bufferSize = bufferSize; + } + + /** + * Use a BER Set to store the recipient information + */ + public void SetBerEncodeRecipients( + bool berEncodeRecipientSet) + { + _berEncodeRecipientSet = berEncodeRecipientSet; + } + + /** + * generate an enveloped object that contains an CMS Enveloped Data + * object using the given provider and the passed in key generator. + * @throws java.io.IOException + */ + private Stream Open( + Stream outStr, + string macOid, + CipherKeyGenerator keyGen) + { + // FIXME Will this work for macs? + byte[] encKeyBytes = keyGen.GenerateKey(); + KeyParameter encKey = ParameterUtilities.CreateKeyParameter(macOid, encKeyBytes); + + Asn1Encodable asn1Params = GenerateAsn1Parameters(macOid, encKeyBytes); + + ICipherParameters cipherParameters; + AlgorithmIdentifier macAlgId = GetAlgorithmIdentifier( + macOid, encKey, asn1Params, out cipherParameters); + + 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); + } + } + + // FIXME Only passing key at the moment +// return Open(outStr, macAlgId, cipherParameters, recipientInfos); + return Open(outStr, macAlgId, encKey, recipientInfos); + } + + protected Stream Open( + Stream outStr, + AlgorithmIdentifier macAlgId, + ICipherParameters cipherParameters, + Asn1EncodableVector recipientInfos) + { + try + { + // + // ContentInfo + // + BerSequenceGenerator cGen = new BerSequenceGenerator(outStr); + + cGen.AddObject(CmsObjectIdentifiers.AuthenticatedData); + + // + // Authenticated Data + // + BerSequenceGenerator authGen = new BerSequenceGenerator( + cGen.GetRawOutputStream(), 0, true); + + authGen.AddObject(new DerInteger(AuthenticatedData.CalculateVersion(null))); + + Stream authRaw = authGen.GetRawOutputStream(); + Asn1Generator recipGen = _berEncodeRecipientSet + ? (Asn1Generator) new BerSetGenerator(authRaw) + : new DerSetGenerator(authRaw); + + foreach (Asn1Encodable ae in recipientInfos) + { + recipGen.AddObject(ae); + } + + recipGen.Close(); + + authGen.AddObject(macAlgId); + + BerSequenceGenerator eiGen = new BerSequenceGenerator(authRaw); + eiGen.AddObject(CmsObjectIdentifiers.Data); + + Stream octetOutputStream = CmsUtilities.CreateBerOctetOutputStream( + eiGen.GetRawOutputStream(), 0, false, _bufferSize); + + IMac mac = MacUtilities.GetMac(macAlgId.ObjectID); + // TODO Confirm no ParametersWithRandom needed + mac.Init(cipherParameters); + Stream mOut = new TeeOutputStream(octetOutputStream, new MacOutputStream(mac)); + + return new CmsAuthenticatedDataOutputStream(mOut, mac, cGen, authGen, 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); + } + } + + /** + * generate an enveloped object that contains an CMS Enveloped Data object + */ + public Stream Open( + Stream outStr, + string encryptionOid) + { + CipherKeyGenerator keyGen = GeneratorUtilities.GetKeyGenerator(encryptionOid); + + keyGen.Init(new KeyGenerationParameters(rand, keyGen.DefaultStrength)); + + return Open(outStr, encryptionOid, keyGen); + } + + /** + * generate an enveloped object that contains an CMS Enveloped Data object + */ + public Stream Open( + Stream outStr, + string encryptionOid, + int keySize) + { + CipherKeyGenerator keyGen = GeneratorUtilities.GetKeyGenerator(encryptionOid); + + keyGen.Init(new KeyGenerationParameters(rand, keySize)); + + return Open(outStr, encryptionOid, keyGen); + } + + private class CmsAuthenticatedDataOutputStream + : BaseOutputStream + { + private readonly Stream macStream; + private readonly IMac mac; + private readonly BerSequenceGenerator cGen; + private readonly BerSequenceGenerator authGen; + private readonly BerSequenceGenerator eiGen; + + public CmsAuthenticatedDataOutputStream( + Stream macStream, + IMac mac, + BerSequenceGenerator cGen, + BerSequenceGenerator authGen, + BerSequenceGenerator eiGen) + { + this.macStream = macStream; + this.mac = mac; + this.cGen = cGen; + this.authGen = authGen; + this.eiGen = eiGen; + } + + public override void WriteByte( + byte b) + { + macStream.WriteByte(b); + } + + public override void Write( + byte[] bytes, + int off, + int len) + { + macStream.Write(bytes, off, len); + } + + public override void Close() + { + macStream.Close(); + + // TODO Parent context(s) should really be be closed explicitly + + eiGen.Close(); + + // [TODO] auth attributes go here + byte[] macOctets = MacUtilities.DoFinal(mac); + authGen.AddObject(new DerOctetString(macOctets)); + // [TODO] unauth attributes go here + + authGen.Close(); + cGen.Close(); + } + } + } +} |