103 lines
2.8 KiB
C#
103 lines
2.8 KiB
C#
using System;
|
|
using Org.BouncyCastle.Asn1;
|
|
using Org.BouncyCastle.Asn1.Cms;
|
|
using Org.BouncyCastle.Asn1.Kisa;
|
|
using Org.BouncyCastle.Asn1.Nist;
|
|
using Org.BouncyCastle.Asn1.Ntt;
|
|
using Org.BouncyCastle.Asn1.Pkcs;
|
|
using Org.BouncyCastle.Asn1.X509;
|
|
using Org.BouncyCastle.Crypto;
|
|
using Org.BouncyCastle.Crypto.Parameters;
|
|
using Org.BouncyCastle.Security;
|
|
using Org.BouncyCastle.Utilities;
|
|
|
|
namespace Org.BouncyCastle.Cms;
|
|
|
|
internal class KekRecipientInfoGenerator : RecipientInfoGenerator
|
|
{
|
|
private static readonly CmsEnvelopedHelper Helper = CmsEnvelopedHelper.Instance;
|
|
|
|
private KeyParameter keyEncryptionKey;
|
|
|
|
private string keyEncryptionKeyOID;
|
|
|
|
private KekIdentifier kekIdentifier;
|
|
|
|
private AlgorithmIdentifier keyEncryptionAlgorithm;
|
|
|
|
internal KekIdentifier KekIdentifier
|
|
{
|
|
set
|
|
{
|
|
kekIdentifier = value;
|
|
}
|
|
}
|
|
|
|
internal KeyParameter KeyEncryptionKey
|
|
{
|
|
set
|
|
{
|
|
keyEncryptionKey = value;
|
|
keyEncryptionAlgorithm = DetermineKeyEncAlg(keyEncryptionKeyOID, keyEncryptionKey);
|
|
}
|
|
}
|
|
|
|
internal string KeyEncryptionKeyOID
|
|
{
|
|
set
|
|
{
|
|
keyEncryptionKeyOID = value;
|
|
}
|
|
}
|
|
|
|
internal KekRecipientInfoGenerator()
|
|
{
|
|
}
|
|
|
|
public RecipientInfo Generate(KeyParameter contentEncryptionKey, SecureRandom random)
|
|
{
|
|
byte[] key = contentEncryptionKey.GetKey();
|
|
IWrapper wrapper = Helper.CreateWrapper(keyEncryptionAlgorithm.Algorithm.Id);
|
|
wrapper.Init(forWrapping: true, new ParametersWithRandom(keyEncryptionKey, random));
|
|
Asn1OctetString encryptedKey = new DerOctetString(wrapper.Wrap(key, 0, key.Length));
|
|
return new RecipientInfo(new KekRecipientInfo(kekIdentifier, keyEncryptionAlgorithm, encryptedKey));
|
|
}
|
|
|
|
private static AlgorithmIdentifier DetermineKeyEncAlg(string algorithm, KeyParameter key)
|
|
{
|
|
if (Platform.StartsWith(algorithm, "DES"))
|
|
{
|
|
return new AlgorithmIdentifier(PkcsObjectIdentifiers.IdAlgCms3DesWrap, DerNull.Instance);
|
|
}
|
|
if (Platform.StartsWith(algorithm, "RC2"))
|
|
{
|
|
return new AlgorithmIdentifier(PkcsObjectIdentifiers.IdAlgCmsRC2Wrap, new DerInteger(58));
|
|
}
|
|
if (Platform.StartsWith(algorithm, "AES"))
|
|
{
|
|
return new AlgorithmIdentifier((key.GetKey().Length * 8) switch
|
|
{
|
|
128 => NistObjectIdentifiers.IdAes128Wrap,
|
|
192 => NistObjectIdentifiers.IdAes192Wrap,
|
|
256 => NistObjectIdentifiers.IdAes256Wrap,
|
|
_ => throw new ArgumentException("illegal keysize in AES"),
|
|
});
|
|
}
|
|
if (Platform.StartsWith(algorithm, "SEED"))
|
|
{
|
|
return new AlgorithmIdentifier(KisaObjectIdentifiers.IdNpkiAppCmsSeedWrap);
|
|
}
|
|
if (Platform.StartsWith(algorithm, "CAMELLIA"))
|
|
{
|
|
return new AlgorithmIdentifier((key.GetKey().Length * 8) switch
|
|
{
|
|
128 => NttObjectIdentifiers.IdCamellia128Wrap,
|
|
192 => NttObjectIdentifiers.IdCamellia192Wrap,
|
|
256 => NttObjectIdentifiers.IdCamellia256Wrap,
|
|
_ => throw new ArgumentException("illegal keysize in Camellia"),
|
|
});
|
|
}
|
|
throw new ArgumentException("unknown algorithm");
|
|
}
|
|
}
|