public SignerInfo Generate(DerObjectIdentifier contentType, AlgorithmIdentifier digestAlgorithm,
byte[] calculatedDigest)
{
try
{
string digestName = Helper.GetDigestAlgName(_digestOID);
string signatureName = digestName + "with" + _encName;
// AlgorithmIdentifier digAlgId = DigestAlgorithmID;
//
// byte[] hash = (byte[])outer._messageHashes[Helper.GetDigestAlgName(this._digestOID)];
// outer._digests[_digestOID] = hash.Clone();
byte[] bytesToSign = calculatedDigest;
/* RFC 3852 5.4
* The result of the message digest calculation process depends on
* whether the signedAttrs field is present. When the field is absent,
* the result is just the message digest of the content as described
*
* above. When the field is present, however, the result is the message
* digest of the complete DER encoding of the SignedAttrs value
* contained in the signedAttrs field.
*/
Asn1Set signedAttr = null;
if (_sAttr != null)
{
IDictionary parameters = outer.GetBaseParameters(contentType, digestAlgorithm, calculatedDigest);
// Asn1.Cms.AttributeTable signed = _sAttr.GetAttributes(Collections.unmodifiableMap(parameters));
Asn1.Cms.AttributeTable signed = _sAttr.GetAttributes(parameters);
if (contentType == null) //counter signature
{
if (signed != null && signed[CmsAttributes.ContentType] != null)
{
IDictionary tmpSigned = signed.ToDictionary();
tmpSigned.Remove(CmsAttributes.ContentType);
signed = new Asn1.Cms.AttributeTable(tmpSigned);
}
}
signedAttr = outer.GetAttributeSet(signed);
// sig must be composed from the DER encoding.
bytesToSign = signedAttr.GetEncoded(Asn1Encodable.Der);
}
else
{
// Note: Need to use raw signatures here since we have already calculated the digest
if (_encName.Equals("RSA"))
{
DigestInfo dInfo = new DigestInfo(digestAlgorithm, calculatedDigest);
bytesToSign = dInfo.GetEncoded(Asn1Encodable.Der);
}
}
_sig.BlockUpdate(bytesToSign, 0, bytesToSign.Length);
byte[] sigBytes = _sig.GenerateSignature();
Asn1Set unsignedAttr = null;
if (_unsAttr != null)
{
IDictionary parameters = outer.GetBaseParameters(
contentType, digestAlgorithm, calculatedDigest);
parameters[CmsAttributeTableParameter.Signature] = sigBytes.Clone();
// Asn1.Cms.AttributeTable unsigned = _unsAttr.getAttributes(Collections.unmodifiableMap(parameters));
Asn1.Cms.AttributeTable unsigned = _unsAttr.GetAttributes(parameters);
unsignedAttr = outer.GetAttributeSet(unsigned);
}
// TODO[RSAPSS] Need the ability to specify non-default parameters
Asn1Encodable sigX509Parameters = SignerUtilities.GetDefaultX509Parameters(signatureName);
AlgorithmIdentifier digestEncryptionAlgorithm = CmsSignedGenerator.GetEncAlgorithmIdentifier(
new DerObjectIdentifier(_encOID), sigX509Parameters);
return(new SignerInfo(_signerIdentifier, digestAlgorithm,
signedAttr, digestEncryptionAlgorithm, new DerOctetString(sigBytes), unsignedAttr));
}
catch (IOException e)
{
throw new CmsStreamException("encoding error.", e);
}
catch (SignatureException e)
{
throw new CmsStreamException("error creating signature.", e);
}
}
internal SignerInfo ToSignerInfo(
DerObjectIdentifier contentType,
CmsProcessable content,
SecureRandom random)
{
AlgorithmIdentifier digAlgId = DigestAlgorithmID;
string digestName = Helper.GetDigestAlgName(digestOID);
IDigest dig = Helper.GetDigestInstance(digestName);
string signatureName = digestName + "with" + Helper.GetEncryptionAlgName(encOID);
ISigner sig = Helper.GetSignatureInstance(signatureName);
// TODO Optimise the case where more than one signer with same digest
if (content != null)
{
content.Write(new DigOutputStream(dig));
}
byte[] hash = DigestUtilities.DoFinal(dig);
outer._digests.Add(digestOID, hash.Clone());
sig.Init(true, new ParametersWithRandom(key, random));
#if NETCF_1_0 || NETCF_2_0 || SILVERLIGHT
Stream sigStr = new SigOutputStream(sig);
#else
Stream sigStr = new BufferedStream(new SigOutputStream(sig));
#endif
Asn1Set signedAttr = null;
if (sAttr != null)
{
IDictionary parameters = outer.GetBaseParameters(contentType, digAlgId, hash);
// Asn1.Cms.AttributeTable signed = sAttr.GetAttributes(Collections.unmodifiableMap(parameters));
Asn1.Cms.AttributeTable signed = sAttr.GetAttributes(parameters);
if (contentType == null) //counter signature
{
if (signed != null && signed[CmsAttributes.ContentType] != null)
{
IDictionary tmpSigned = signed.ToDictionary();
tmpSigned.Remove(CmsAttributes.ContentType);
signed = new Asn1.Cms.AttributeTable(tmpSigned);
}
}
// TODO Validate proposed signed attributes
signedAttr = outer.GetAttributeSet(signed);
// sig must be composed from the DER encoding.
new DerOutputStream(sigStr).WriteObject(signedAttr);
}
else if (content != null)
{
// TODO Use raw signature of the hash value instead
content.Write(sigStr);
}
sigStr.Close();
byte[] sigBytes = sig.GenerateSignature();
Asn1Set unsignedAttr = null;
if (unsAttr != null)
{
IDictionary baseParameters = outer.GetBaseParameters(contentType, digAlgId, hash);
baseParameters[CmsAttributeTableParameter.Signature] = sigBytes.Clone();
// Asn1.Cms.AttributeTable unsigned = unsAttr.GetAttributes(Collections.unmodifiableMap(baseParameters));
Asn1.Cms.AttributeTable unsigned = unsAttr.GetAttributes(baseParameters);
// TODO Validate proposed unsigned attributes
unsignedAttr = outer.GetAttributeSet(unsigned);
}
// TODO[RSAPSS] Need the ability to specify non-default parameters
Asn1Encodable sigX509Parameters = SignerUtilities.GetDefaultX509Parameters(signatureName);
AlgorithmIdentifier encAlgId = CmsSignedGenerator.GetEncAlgorithmIdentifier(
new DerObjectIdentifier(encOID), sigX509Parameters);
return(new SignerInfo(signerIdentifier, digAlgId,
signedAttr, encAlgId, new DerOctetString(sigBytes), unsignedAttr));
}