92 lines
2.7 KiB
C#
92 lines
2.7 KiB
C#
using System;
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using System.IO;
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using Org.BouncyCastle.Asn1;
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using Org.BouncyCastle.Asn1.Cms;
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using Org.BouncyCastle.Asn1.Pkcs;
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using Org.BouncyCastle.Asn1.X509;
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using Org.BouncyCastle.Crypto;
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using Org.BouncyCastle.Crypto.Parameters;
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using Org.BouncyCastle.Security;
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namespace Org.BouncyCastle.Cms;
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public class KeyTransRecipientInformation : RecipientInformation
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{
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private KeyTransRecipientInfo info;
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internal KeyTransRecipientInformation(KeyTransRecipientInfo info, CmsSecureReadable secureReadable)
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: base(info.KeyEncryptionAlgorithm, secureReadable)
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{
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this.info = info;
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rid = new RecipientID();
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RecipientIdentifier recipientIdentifier = info.RecipientIdentifier;
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try
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{
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if (recipientIdentifier.IsTagged)
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{
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Asn1OctetString instance = Asn1OctetString.GetInstance(recipientIdentifier.ID);
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rid.SubjectKeyIdentifier = instance.GetOctets();
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}
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else
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{
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Org.BouncyCastle.Asn1.Cms.IssuerAndSerialNumber instance2 = Org.BouncyCastle.Asn1.Cms.IssuerAndSerialNumber.GetInstance(recipientIdentifier.ID);
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rid.Issuer = instance2.Name;
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rid.SerialNumber = instance2.SerialNumber.Value;
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}
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}
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catch (IOException)
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{
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throw new ArgumentException("invalid rid in KeyTransRecipientInformation");
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}
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}
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private string GetExchangeEncryptionAlgorithmName(AlgorithmIdentifier algo)
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{
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DerObjectIdentifier algorithm = algo.Algorithm;
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if (PkcsObjectIdentifiers.RsaEncryption.Equals(algorithm))
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{
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return "RSA//PKCS1Padding";
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}
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if (PkcsObjectIdentifiers.IdRsaesOaep.Equals(algorithm))
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{
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RsaesOaepParameters instance = RsaesOaepParameters.GetInstance(algo.Parameters);
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return "RSA//OAEPWITH" + DigestUtilities.GetAlgorithmName(instance.HashAlgorithm.Algorithm) + "ANDMGF1Padding";
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}
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return algorithm.Id;
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}
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internal KeyParameter UnwrapKey(ICipherParameters key)
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{
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byte[] octets = info.EncryptedKey.GetOctets();
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string exchangeEncryptionAlgorithmName = GetExchangeEncryptionAlgorithmName(keyEncAlg);
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try
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{
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IWrapper wrapper = WrapperUtilities.GetWrapper(exchangeEncryptionAlgorithmName);
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wrapper.Init(forWrapping: false, key);
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return ParameterUtilities.CreateKeyParameter(GetContentAlgorithmName(), wrapper.Unwrap(octets, 0, octets.Length));
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}
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catch (SecurityUtilityException e)
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{
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throw new CmsException("couldn't create cipher.", e);
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}
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catch (InvalidKeyException e2)
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{
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throw new CmsException("key invalid in message.", e2);
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}
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catch (DataLengthException e3)
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{
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throw new CmsException("illegal blocksize in message.", e3);
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}
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catch (InvalidCipherTextException e4)
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{
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throw new CmsException("bad padding in message.", e4);
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}
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}
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public override CmsTypedStream GetContentStream(ICipherParameters key)
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{
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KeyParameter sKey = UnwrapKey(key);
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return GetContentFromSessionKey(sKey);
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}
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}
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