public RecipientInfo Generate(KeyParameter contentEncryptionKey, SecureRandom random)
{
byte[] keyBytes = contentEncryptionKey.GetKey();
string rfc3211WrapperName = Helper.GetRfc3211WrapperName(keyEncryptionKeyOID);
IWrapper keyWrapper = Helper.CreateWrapper(rfc3211WrapperName);
// Note: In Java build, the IV is automatically generated in JCE layer
int ivLength = rfc3211WrapperName.StartsWith("DESEDE") ? 8 : 16;
byte[] iv = new byte[ivLength];
random.NextBytes(iv);
ICipherParameters parameters = new ParametersWithIV(keyEncryptionKey, iv);
keyWrapper.Init(true, new ParametersWithRandom(parameters, random));
Asn1OctetString encryptedKey = new DerOctetString(
keyWrapper.Wrap(keyBytes, 0, keyBytes.Length));
DerSequence seq = new DerSequence(
new DerObjectIdentifier(keyEncryptionKeyOID),
new DerOctetString(iv));
AlgorithmIdentifier keyEncryptionAlgorithm = new AlgorithmIdentifier(
PkcsObjectIdentifiers.IdAlgPwriKek, seq);
return new RecipientInfo(new PasswordRecipientInfo(
keyDerivationAlgorithm, keyEncryptionAlgorithm, encryptedKey));
}
public RecipientInfo Generate(KeyParameter contentEncryptionKey, SecureRandom random)
{
byte[] keyBytes = contentEncryptionKey.GetKey();
IWrapper keyWrapper = Helper.CreateWrapper(keyEncryptionAlgorithm.ObjectID.Id);
keyWrapper.Init(true, new ParametersWithRandom(keyEncryptionKey, random));
Asn1OctetString encryptedKey = new DerOctetString(
keyWrapper.Wrap(keyBytes, 0, keyBytes.Length));
return new RecipientInfo(new KekRecipientInfo(kekIdentifier, keyEncryptionAlgorithm, encryptedKey));
}
public RecipientInfo Generate(KeyParameter contentEncryptionKey, SecureRandom random)
{
byte[] keyBytes = contentEncryptionKey.GetKey();
AlgorithmIdentifier keyEncryptionAlgorithm = info.AlgorithmID;
IWrapper keyWrapper = Helper.CreateWrapper(keyEncryptionAlgorithm.ObjectID.Id);
keyWrapper.Init(true, new ParametersWithRandom(recipientPublicKey, random));
byte[] encryptedKeyBytes = keyWrapper.Wrap(keyBytes, 0, keyBytes.Length);
RecipientIdentifier recipId;
if (recipientTbsCert != null)
{
IssuerAndSerialNumber issuerAndSerial = new IssuerAndSerialNumber(
recipientTbsCert.Issuer, recipientTbsCert.SerialNumber.Value);
recipId = new RecipientIdentifier(issuerAndSerial);
}
else
{
recipId = new RecipientIdentifier(subjectKeyIdentifier);
}
return new RecipientInfo(new KeyTransRecipientInfo(recipId, keyEncryptionAlgorithm,
new DerOctetString(encryptedKeyBytes)));
}
public RecipientInfo Generate(KeyParameter contentEncryptionKey, SecureRandom random)
{
byte[] keyBytes = contentEncryptionKey.GetKey();
AsymmetricKeyParameter senderPublicKey = senderKeyPair.Public;
ICipherParameters senderPrivateParams = senderKeyPair.Private;
OriginatorIdentifierOrKey originator;
try
{
originator = new OriginatorIdentifierOrKey(
CreateOriginatorPublicKey(senderPublicKey));
}
catch (IOException e)
{
throw new InvalidKeyException("cannot extract originator public key: " + e);
}
Asn1OctetString ukm = null;
if (keyAgreementOID.Id.Equals(CmsEnvelopedGenerator.ECMqvSha1Kdf))
{
try
{
IAsymmetricCipherKeyPairGenerator ephemKPG =
GeneratorUtilities.GetKeyPairGenerator(keyAgreementOID);
ephemKPG.Init(
((ECPublicKeyParameters)senderPublicKey).CreateKeyGenerationParameters(random));
AsymmetricCipherKeyPair ephemKP = ephemKPG.GenerateKeyPair();
ukm = new DerOctetString(
new MQVuserKeyingMaterial(
CreateOriginatorPublicKey(ephemKP.Public), null));
senderPrivateParams = new MqvPrivateParameters(
(ECPrivateKeyParameters)senderPrivateParams,
(ECPrivateKeyParameters)ephemKP.Private,
(ECPublicKeyParameters)ephemKP.Public);
}
catch (IOException e)
{
throw new InvalidKeyException("cannot extract MQV ephemeral public key: " + e);
}
catch (SecurityUtilityException e)
{
throw new InvalidKeyException("cannot determine MQV ephemeral key pair parameters from public key: " + e);
}
}
DerSequence paramSeq = new DerSequence(
keyEncryptionOID,
DerNull.Instance);
AlgorithmIdentifier keyEncAlg = new AlgorithmIdentifier(keyAgreementOID, paramSeq);
Asn1EncodableVector recipientEncryptedKeys = new Asn1EncodableVector();
foreach (X509Certificate recipientCert in recipientCerts)
{
TbsCertificateStructure tbsCert;
try
{
tbsCert = TbsCertificateStructure.GetInstance(
Asn1Object.FromByteArray(recipientCert.GetTbsCertificate()));
}
catch (Exception)
{
throw new ArgumentException("can't extract TBS structure from certificate");
}
// TODO Should there be a SubjectKeyIdentifier-based alternative?
IssuerAndSerialNumber issuerSerial = new IssuerAndSerialNumber(
tbsCert.Issuer, tbsCert.SerialNumber.Value);
KeyAgreeRecipientIdentifier karid = new KeyAgreeRecipientIdentifier(issuerSerial);
ICipherParameters recipientPublicParams = recipientCert.GetPublicKey();
if (keyAgreementOID.Id.Equals(CmsEnvelopedGenerator.ECMqvSha1Kdf))
{
recipientPublicParams = new MqvPublicParameters(
(ECPublicKeyParameters)recipientPublicParams,
(ECPublicKeyParameters)recipientPublicParams);
}
// Use key agreement to choose a wrap key for this recipient
IBasicAgreement keyAgreement = AgreementUtilities.GetBasicAgreementWithKdf(
keyAgreementOID, keyEncryptionOID.Id);
keyAgreement.Init(new ParametersWithRandom(senderPrivateParams, random));
BigInteger agreedValue = keyAgreement.CalculateAgreement(recipientPublicParams);
int keyEncryptionKeySize = GeneratorUtilities.GetDefaultKeySize(keyEncryptionOID) / 8;
byte[] keyEncryptionKeyBytes = X9IntegerConverter.IntegerToBytes(agreedValue, keyEncryptionKeySize);
KeyParameter keyEncryptionKey = ParameterUtilities.CreateKeyParameter(
keyEncryptionOID, keyEncryptionKeyBytes);
// Wrap the content encryption key with the agreement key
IWrapper keyWrapper = Helper.CreateWrapper(keyEncryptionOID.Id);
keyWrapper.Init(true, new ParametersWithRandom(keyEncryptionKey, random));
byte[] encryptedKeyBytes = keyWrapper.Wrap(keyBytes, 0, keyBytes.Length);
Asn1OctetString encryptedKey = new DerOctetString(encryptedKeyBytes);
recipientEncryptedKeys.Add(new RecipientEncryptedKey(karid, encryptedKey));
}
return new RecipientInfo(new KeyAgreeRecipientInfo(originator, ukm, keyEncAlg,
new DerSequence(recipientEncryptedKeys)));
}
private static AlgorithmIdentifier DetermineKeyEncAlg(
string algorithm, KeyParameter key)
{
if (algorithm.StartsWith("DES"))
{
return new AlgorithmIdentifier(
PkcsObjectIdentifiers.IdAlgCms3DesWrap,
DerNull.Instance);
}
else if (algorithm.StartsWith("RC2"))
{
return new AlgorithmIdentifier(
PkcsObjectIdentifiers.IdAlgCmsRC2Wrap,
new DerInteger(58));
}
else if (algorithm.StartsWith("AES"))
{
int length = key.GetKey().Length * 8;
DerObjectIdentifier wrapOid;
if (length == 128)
{
wrapOid = NistObjectIdentifiers.IdAes128Wrap;
}
else if (length == 192)
{
wrapOid = NistObjectIdentifiers.IdAes192Wrap;
}
else if (length == 256)
{
wrapOid = NistObjectIdentifiers.IdAes256Wrap;
}
else
{
throw new ArgumentException("illegal keysize in AES");
}
return new AlgorithmIdentifier(wrapOid); // parameters absent
}
else if (algorithm.StartsWith("SEED"))
{
// parameters absent
return new AlgorithmIdentifier(KisaObjectIdentifiers.IdNpkiAppCmsSeedWrap);
}
else if (algorithm.StartsWith("CAMELLIA"))
{
int length = key.GetKey().Length * 8;
DerObjectIdentifier wrapOid;
if (length == 128)
{
wrapOid = NttObjectIdentifiers.IdCamellia128Wrap;
}
else if (length == 192)
{
wrapOid = NttObjectIdentifiers.IdCamellia192Wrap;
}
else if (length == 256)
{
wrapOid = NttObjectIdentifiers.IdCamellia256Wrap;
}
else
{
throw new ArgumentException("illegal keysize in Camellia");
}
return new AlgorithmIdentifier(wrapOid); // parameters must be absent
}
else
{
throw new ArgumentException("unknown algorithm");
}
}
private byte[] CreateSessionInfo(
SymmetricKeyAlgorithmTag algorithm,
KeyParameter key)
{
byte[] keyBytes = key.GetKey();
byte[] sessionInfo = new byte[keyBytes.Length + 3];
sessionInfo[0] = (byte) algorithm;
keyBytes.CopyTo(sessionInfo, 1);
AddCheckSum(sessionInfo);
return sessionInfo;
}