/// <summary>
/// Generate an enveloped object that contains a CMS Enveloped Data
/// object using the passed in key generator.
/// </summary>
private CmsEnvelopedData Generate(
CmsProcessable content,
string encryptionOid,
CipherKeyGenerator keyGen)
{
AlgorithmIdentifier encAlgId = null;
KeyParameter encKey;
Asn1OctetString encContent;
try
{
byte[] encKeyBytes = keyGen.GenerateKey();
encKey = ParameterUtilities.CreateKeyParameter(encryptionOid, encKeyBytes);
Asn1Encodable asn1Params = GenerateAsn1Parameters(encryptionOid, encKeyBytes);
ICipherParameters cipherParameters;
encAlgId = GetAlgorithmIdentifier(
encryptionOid, encKey, asn1Params, out cipherParameters);
IBufferedCipher cipher = CipherUtilities.GetCipher(encryptionOid);
cipher.Init(true, new ParametersWithRandom(cipherParameters, rand));
MemoryStream bOut = new MemoryStream();
CipherStream cOut = new CipherStream(bOut, null, cipher);
content.Write(cOut);
cOut.Dispose();
encContent = new BerOctetString(bOut.ToArray());
}
catch (SecurityUtilityException e)
{
throw new CmsException("couldn't create cipher.", e);
}
catch (InvalidKeyException e)
{
throw new CmsException("key invalid in message.", e);
}
catch (IOException e)
{
throw new CmsException("exception decoding algorithm parameters.", e);
}
Asn1EncodableVector recipientInfos = new Asn1EncodableVector();
foreach (RecipientInfoGenerator rig in recipientInfoGenerators)
{
try
{
recipientInfos.Add(rig.Generate(encKey, rand));
}
catch (InvalidKeyException e)
{
throw new CmsException("key inappropriate for algorithm.", e);
}
catch (GeneralSecurityException e)
{
throw new CmsException("error making encrypted content.", e);
}
}
EncryptedContentInfo eci = new EncryptedContentInfo(
CmsObjectIdentifiers.Data,
encAlgId,
encContent);
Asn1Set unprotectedAttrSet = null;
if (unprotectedAttributeGenerator != null)
{
Asn1.Cms.AttributeTable attrTable = unprotectedAttributeGenerator.GetAttributes(Platform.CreateHashtable());
unprotectedAttrSet = new BerSet(attrTable.ToAsn1EncodableVector());
}
ContentInfo contentInfo = new ContentInfo(
CmsObjectIdentifiers.EnvelopedData,
new EnvelopedData(null, new DerSet(recipientInfos), eci, unprotectedAttrSet));
return new CmsEnvelopedData(contentInfo);
}
/// <summary>
/// Generate an enveloped object that contains an CMS Enveloped Data
/// object using the passed in key generator.
/// </summary>
private Stream Open(
Stream outStream,
string encryptionOid,
CipherKeyGenerator keyGen)
{
byte[] encKeyBytes = keyGen.GenerateKey();
KeyParameter encKey = ParameterUtilities.CreateKeyParameter(encryptionOid, encKeyBytes);
Asn1Encodable asn1Params = GenerateAsn1Parameters(encryptionOid, encKeyBytes);
ICipherParameters cipherParameters;
AlgorithmIdentifier encAlgID = GetAlgorithmIdentifier(
encryptionOid, encKey, asn1Params, out cipherParameters);
Asn1EncodableVector recipientInfos = new Asn1EncodableVector();
foreach (RecipientInfoGenerator rig in recipientInfoGenerators)
{
try
{
recipientInfos.Add(rig.Generate(encKey, rand));
}
catch (InvalidKeyException e)
{
throw new CmsException("key inappropriate for algorithm.", e);
}
catch (GeneralSecurityException e)
{
throw new CmsException("error making encrypted content.", e);
}
}
return Open(outStream, encAlgID, cipherParameters, recipientInfos);
}
/**
* generate an enveloped object that contains an CMS Enveloped Data
* object using the given provider and the passed in key generator.
*/
private CmsAuthenticatedData Generate(
CmsProcessable content,
string macOid,
CipherKeyGenerator keyGen)
{
AlgorithmIdentifier macAlgId;
KeyParameter encKey;
Asn1OctetString encContent;
Asn1OctetString macResult;
try
{
// FIXME Will this work for macs?
byte[] encKeyBytes = keyGen.GenerateKey();
encKey = ParameterUtilities.CreateKeyParameter(macOid, encKeyBytes);
Asn1Encodable asn1Params = GenerateAsn1Parameters(macOid, encKeyBytes);
ICipherParameters cipherParameters;
macAlgId = GetAlgorithmIdentifier(
macOid, encKey, asn1Params, out cipherParameters);
IMac mac = MacUtilities.GetMac(macOid);
// TODO Confirm no ParametersWithRandom needed
// FIXME Only passing key at the moment
// mac.Init(cipherParameters);
mac.Init(encKey);
MemoryStream bOut = new MemoryStream();
Stream mOut = new TeeOutputStream(bOut, new MacOutputStream(mac));
content.Write(mOut);
mOut.Dispose();
bOut.Dispose();
encContent = new BerOctetString(bOut.ToArray());
byte[] macOctets = MacUtilities.DoFinal(mac);
macResult = new DerOctetString(macOctets);
}
catch (SecurityUtilityException e)
{
throw new CmsException("couldn't create cipher.", e);
}
catch (InvalidKeyException e)
{
throw new CmsException("key invalid in message.", e);
}
catch (IOException e)
{
throw new CmsException("exception decoding algorithm parameters.", e);
}
Asn1EncodableVector recipientInfos = new Asn1EncodableVector();
foreach (RecipientInfoGenerator rig in recipientInfoGenerators)
{
try
{
recipientInfos.Add(rig.Generate(encKey, rand));
}
catch (InvalidKeyException e)
{
throw new CmsException("key inappropriate for algorithm.", e);
}
catch (GeneralSecurityException e)
{
throw new CmsException("error making encrypted content.", e);
}
}
ContentInfo eci = new ContentInfo(CmsObjectIdentifiers.Data, encContent);
ContentInfo contentInfo = new ContentInfo(
CmsObjectIdentifiers.AuthenticatedData,
new AuthenticatedData(null, new DerSet(recipientInfos), macAlgId, null, eci, null, macResult, null));
return new CmsAuthenticatedData(contentInfo);
}
