diff options
Diffstat (limited to 'crypto/src/cms/CMSEnvelopedDataStreamGenerator.cs')
| -rw-r--r-- | crypto/src/cms/CMSEnvelopedDataStreamGenerator.cs | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/crypto/src/cms/CMSEnvelopedDataStreamGenerator.cs b/crypto/src/cms/CMSEnvelopedDataStreamGenerator.cs new file mode 100644 index 000000000..a63ea7b7f --- /dev/null +++ b/crypto/src/cms/CMSEnvelopedDataStreamGenerator.cs @@ -0,0 +1,281 @@ +using System; +using System.Collections; +using System.IO; + +using Org.BouncyCastle.Asn1; +using Org.BouncyCastle.Asn1.Cms; +using Org.BouncyCastle.Asn1.Nist; +using Org.BouncyCastle.Asn1.X509; +using Org.BouncyCastle.Crypto; +using Org.BouncyCastle.Crypto.Engines; +using Org.BouncyCastle.Crypto.Generators; +using Org.BouncyCastle.Crypto.IO; +using Org.BouncyCastle.Crypto.Parameters; +using Org.BouncyCastle.Security; +using Org.BouncyCastle.Security.Certificates; +using Org.BouncyCastle.Utilities; +using Org.BouncyCastle.Utilities.IO; +using Org.BouncyCastle.X509; + +namespace Org.BouncyCastle.Cms +{ + /** + * General class for generating a CMS enveloped-data message stream. + * <p> + * A simple example of usage. + * <pre> + * CmsEnvelopedDataStreamGenerator edGen = new CmsEnvelopedDataStreamGenerator(); + * + * edGen.AddKeyTransRecipient(cert); + * + * MemoryStream bOut = new MemoryStream(); + * + * Stream out = edGen.Open( + * bOut, CMSEnvelopedDataGenerator.AES128_CBC);* + * out.Write(data); + * + * out.Close(); + * </pre> + * </p> + */ + public class CmsEnvelopedDataStreamGenerator + : CmsEnvelopedGenerator + { + private object _originatorInfo = null; + private object _unprotectedAttributes = null; + private int _bufferSize; + private bool _berEncodeRecipientSet; + + public CmsEnvelopedDataStreamGenerator() + { + } + + /// <summary>Constructor allowing specific source of randomness</summary> + /// <param name="rand">Instance of <c>SecureRandom</c> to use.</param> + public CmsEnvelopedDataStreamGenerator( + SecureRandom rand) + : base(rand) + { + } + + /// <summary>Set the underlying string size for encapsulated data.</summary> + /// <param name="bufferSize">Length of octet strings to buffer the data.</param> + public void SetBufferSize( + int bufferSize) + { + _bufferSize = bufferSize; + } + + /// <summary>Use a BER Set to store the recipient information.</summary> + public void SetBerEncodeRecipients( + bool berEncodeRecipientSet) + { + _berEncodeRecipientSet = berEncodeRecipientSet; + } + + private DerInteger Version + { + get + { + int version = (_originatorInfo != null || _unprotectedAttributes != null) + ? 2 + : 0; + + return new DerInteger(version); + } + } + + /// <summary> + /// Generate an enveloped object that contains an CMS Enveloped Data + /// object using the passed in key generator. + /// </summary> + private Stream Open( + Stream outStream, + string encryptionOid, + CipherKeyGenerator keyGen) + { + byte[] encKeyBytes = keyGen.GenerateKey(); + KeyParameter encKey = ParameterUtilities.CreateKeyParameter(encryptionOid, encKeyBytes); + + Asn1Encodable asn1Params = GenerateAsn1Parameters(encryptionOid, encKeyBytes); + + ICipherParameters cipherParameters; + AlgorithmIdentifier encAlgID = GetAlgorithmIdentifier( + encryptionOid, 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); + } + } + + return Open(outStream, encAlgID, cipherParameters, recipientInfos); + } + + 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); + } + } + + /** + * generate an enveloped object that contains an CMS Enveloped Data object + * @throws IOException + */ + public Stream Open( + Stream outStream, + string encryptionOid) + { + CipherKeyGenerator keyGen = GeneratorUtilities.GetKeyGenerator(encryptionOid); + + keyGen.Init(new KeyGenerationParameters(rand, keyGen.DefaultStrength)); + + return Open(outStream, encryptionOid, keyGen); + } + + /** + * generate an enveloped object that contains an CMS Enveloped Data object + * @throws IOException + */ + public Stream Open( + Stream outStream, + string encryptionOid, + int keySize) + { + CipherKeyGenerator keyGen = GeneratorUtilities.GetKeyGenerator(encryptionOid); + + keyGen.Init(new KeyGenerationParameters(rand, keySize)); + + return Open(outStream, encryptionOid, keyGen); + } + + private class CmsEnvelopedDataOutputStream + : BaseOutputStream + { + private readonly CmsEnvelopedGenerator _outer; + + private readonly CipherStream _out; + private readonly BerSequenceGenerator _cGen; + private readonly BerSequenceGenerator _envGen; + private readonly BerSequenceGenerator _eiGen; + + public CmsEnvelopedDataOutputStream( + CmsEnvelopedGenerator outer, + CipherStream outStream, + BerSequenceGenerator cGen, + BerSequenceGenerator envGen, + BerSequenceGenerator eiGen) + { + _outer = outer; + _out = outStream; + _cGen = cGen; + _envGen = envGen; + _eiGen = eiGen; + } + + public override void WriteByte( + byte b) + { + _out.WriteByte(b); + } + + public override void Write( + byte[] bytes, + int off, + int len) + { + _out.Write(bytes, off, len); + } + + public override void Close() + { + _out.Close(); + + // TODO Parent context(s) should really be be closed explicitly + + _eiGen.Close(); + + if (_outer.unprotectedAttributeGenerator != null) + { + Asn1.Cms.AttributeTable attrTable = _outer.unprotectedAttributeGenerator.GetAttributes(Platform.CreateHashtable()); + + Asn1Set unprotectedAttrs = new BerSet(attrTable.ToAsn1EncodableVector()); + + _envGen.AddObject(new DerTaggedObject(false, 1, unprotectedAttrs)); + } + + _envGen.Close(); + _cGen.Close(); + base.Close(); + } + } + } +} |