diff --git a/crypto/src/cms/EnvelopedDataHelper.cs b/crypto/src/cms/EnvelopedDataHelper.cs
new file mode 100644
index 000000000..89ec79691
--- /dev/null
+++ b/crypto/src/cms/EnvelopedDataHelper.cs
@@ -0,0 +1,123 @@
+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;
+
+namespace Org.BouncyCastle.Cms
+{
+ public 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();
+ }
+ }
+}
\ No newline at end of file
|
