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using System.Collections;
using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.Nist;
using Org.BouncyCastle.Asn1.Oiw;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Digests;
using Org.BouncyCastle.Crypto.Engines;
using Org.BouncyCastle.Crypto.Operators;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto.Utilities;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Crypto.Utilites;
namespace Org.BouncyCastle.Cms
{
internal class EnvelopedDataHelper
{
private static readonly IDictionary BaseCipherNames = Platform.CreateHashtable();
private static readonly IDictionary MacAlgNames = Platform.CreateHashtable();
private static readonly IDictionary prfs = Platform.CreateHashtable();
public delegate IDigest DigestCreator();
static EnvelopedDataHelper()
{
prfs.Add(PkcsObjectIdentifiers.IdHmacWithSha1, new DigestProvider(delegate () { return new Sha1Digest(); }));
prfs.Add(PkcsObjectIdentifiers.IdHmacWithSha224, new DigestProvider(delegate () { return new Sha224Digest(); }));
prfs.Add(PkcsObjectIdentifiers.IdHmacWithSha256, new DigestProvider(delegate () { return new Sha256Digest(); }));
prfs.Add(PkcsObjectIdentifiers.IdHmacWithSha384, new DigestProvider(delegate () { return new Sha384Digest(); }));
prfs.Add(PkcsObjectIdentifiers.IdHmacWithSha512, new DigestProvider(delegate () { return new Sha512Digest(); }));
BaseCipherNames.Add(PkcsObjectIdentifiers.DesEde3Cbc, "DESEDE");
BaseCipherNames.Add(NistObjectIdentifiers.IdAes128Cbc, "AES");
BaseCipherNames.Add(NistObjectIdentifiers.IdAes192Cbc, "AES");
BaseCipherNames.Add(NistObjectIdentifiers.IdAes256Cbc, "AES");
MacAlgNames.Add(PkcsObjectIdentifiers.DesEde3Cbc, "DESEDEMac");
MacAlgNames.Add(NistObjectIdentifiers.IdAes128Cbc, "AESMac");
MacAlgNames.Add(NistObjectIdentifiers.IdAes192Cbc, "AESMac");
MacAlgNames.Add(NistObjectIdentifiers.IdAes256Cbc, "AESMac");
MacAlgNames.Add(PkcsObjectIdentifiers.RC2Cbc, "RC2Mac");
}
static IDigest GetPrf(AlgorithmIdentifier algID)
{
return ((DigestCreator)prfs[algID]).Invoke();
}
static IWrapper CreateRFC3211Wrapper(DerObjectIdentifier algorithm)
{
if (NistObjectIdentifiers.IdAes128Cbc.Equals(algorithm)
|| NistObjectIdentifiers.IdAes192Cbc.Equals(algorithm)
|| NistObjectIdentifiers.IdAes256Cbc.Equals(algorithm))
{
return new Rfc3211WrapEngine(new AesEngine());
}
else if (PkcsObjectIdentifiers.DesEde3Cbc.Equals(algorithm))
{
return new Rfc3211WrapEngine(new DesEdeEngine());
}
else if (OiwObjectIdentifiers.DesCbc.Equals(algorithm))
{
return new Rfc3211WrapEngine(new DesEngine());
}
else if (PkcsObjectIdentifiers.RC2Cbc.Equals(algorithm))
{
return new Rfc3211WrapEngine(new RC2Engine());
}
else
{
throw new CmsException("cannot recognise wrapper: " + algorithm);
}
}
public static object CreateContentCipher(bool forEncryption, ICipherParameters encKey,
AlgorithmIdentifier encryptionAlgID)
{
return CipherFactory.CreateContentCipher(forEncryption, encKey, encryptionAlgID);
}
public AlgorithmIdentifier GenerateEncryptionAlgID(DerObjectIdentifier encryptionOID, KeyParameter encKey, SecureRandom random)
{
return AlgorithmIdentifierFactory.GenerateEncryptionAlgID(encryptionOID, encKey.GetKey().Length * 8, random);
}
public CipherKeyGenerator CreateKeyGenerator(DerObjectIdentifier algorithm, SecureRandom random)
{
return CipherKeyGeneratorFactory.CreateKeyGenerator(algorithm, random);
}
}
// This exists because we can't directly put a delegate in a map as it is
// not an object.
internal class DigestProvider
{
private readonly EnvelopedDataHelper.DigestCreator creator;
public DigestProvider(EnvelopedDataHelper.DigestCreator creator)
{
this.creator = creator;
}
public IDigest Create()
{
return creator.Invoke();
}
}
}
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