internal protected virtual Asn1Set GetAttributeSet(
AttributeTable attr)
{
return(attr == null
? null
: new DerSet(attr.ToAsn1EncodableVector()));
}
/**
* return a table of the unauthenticated attributes indexed by
* the OID of the attribute.
* @exception java.io.IOException
*/
public AttributeTable GetUnauthAttrs()
{
if (unauthAttrs == null && unauthAttrNotRead)
{
Asn1SetParser s = authData.GetUnauthAttrs();
unauthAttrNotRead = false;
if (s != null)
{
Asn1EncodableVector v = new Asn1EncodableVector();
IAsn1Convertible o;
while ((o = s.ReadObject()) != null)
{
Asn1SequenceParser seq = (Asn1SequenceParser)o;
v.Add(seq.ToAsn1Object());
}
unauthAttrs = new AttributeTable(new DerSet(v));
}
}
return(unauthAttrs);
}
/**
* return a table of the unprotected attributes indexed by
* the OID of the attribute.
* @throws IOException
*/
public AttributeTable GetUnprotectedAttributes()
{
if (_unprotectedAttributes == null && _attrNotRead)
{
Asn1SetParser asn1Set = this.envelopedData.GetUnprotectedAttrs();
_attrNotRead = false;
if (asn1Set != null)
{
Asn1EncodableVector v = new Asn1EncodableVector();
IAsn1Convertible o;
while ((o = asn1Set.ReadObject()) != null)
{
Asn1SequenceParser seq = (Asn1SequenceParser)o;
v.Add(seq.ToAsn1Object());
}
_unprotectedAttributes = new AttributeTable(new DerSet(v));
}
}
return(_unprotectedAttributes);
}
/**
* Return a new table with the passed in attribute added.
*
* @param attrType
* @param attrValue
* @return
*/
public AttributeTable Add(DerObjectIdentifier attrType, Asn1Encodable attrValue)
{
AttributeTable newTable = new AttributeTable(attributes);
newTable.AddAttribute(new Attribute(attrType, new DerSet(attrValue)));
return(newTable);
}
public AttributeTable Remove(DerObjectIdentifier attrType)
{
AttributeTable newTable = new AttributeTable(attributes);
newTable.attributes.Remove(attrType);
return(newTable);
}
/**
* add a signer with extra signed/unsigned attributes.
*
* @param key signing key to use
* @param cert certificate containing corresponding public key
* @param digestOID digest algorithm OID
* @param signedAttr table of attributes to be included in signature
* @param unsignedAttr table of attributes to be included as unsigned
*/
public void AddSigner(
AsymmetricKeyParameter privateKey,
X509Certificate cert,
string digestOID,
AttributeTable signedAttr,
AttributeTable unsignedAttr)
{
AddSigner(privateKey, cert, Helper.GetEncOid(privateKey, digestOID), digestOID,
signedAttr, unsignedAttr);
}
/**
* add a signer with extra signed/unsigned attributes.
*
* @param key signing key to use
* @param subjectKeyID subjectKeyID of corresponding public key
* @param digestOID digest algorithm OID
* @param signedAttr table of attributes to be included in signature
* @param unsignedAttr table of attributes to be included as unsigned
*/
public void AddSigner(
AsymmetricKeyParameter privateKey,
byte[] subjectKeyID,
string digestOID,
AttributeTable signedAttr,
AttributeTable unsignedAttr)
{
AddSigner(privateKey, subjectKeyID, Helper.GetEncOid(privateKey, digestOID), digestOID,
signedAttr, unsignedAttr);
}
/**
* add a signer with extra signed/unsigned attributes.
* @throws NoSuchAlgorithmException
* @throws InvalidKeyException
*/
public void AddSigner(
AsymmetricKeyParameter privateKey,
byte[] subjectKeyID,
string digestOid,
AttributeTable signedAttr,
AttributeTable unsignedAttr)
{
AddSigner(privateKey, subjectKeyID, digestOid,
new DefaultSignedAttributeTableGenerator(signedAttr),
new SimpleAttributeTableGenerator(unsignedAttr));
}
/**
* add a signer with extra signed/unsigned attributes.
* @throws NoSuchAlgorithmException
* @throws InvalidKeyException
*/
public void AddSigner(
AsymmetricKeyParameter privateKey,
X509Certificate cert,
string digestOid,
AttributeTable signedAttr,
AttributeTable unsignedAttr)
{
AddSigner(privateKey, cert, digestOid,
new DefaultSignedAttributeTableGenerator(signedAttr),
new SimpleAttributeTableGenerator(unsignedAttr));
}
private void doAddSigner(
AsymmetricKeyParameter privateKey,
SignerIdentifier signerIdentifier,
string encryptionOID,
string digestOID,
CmsAttributeTableGenerator signedAttrGen,
CmsAttributeTableGenerator unsignedAttrGen,
AttributeTable baseSignedTable)
{
signerInfs.Add(new SignerInf(this, privateKey, signerIdentifier, digestOID, encryptionOID,
signedAttrGen, unsignedAttrGen, baseSignedTable));
}
/**
* add a signer, specifying the digest encryption algorithm, with extra signed/unsigned attributes.
*
* @param key signing key to use
* @param subjectKeyID subjectKeyID of corresponding public key
* @param encryptionOID digest encryption algorithm OID
* @param digestOID digest algorithm OID
* @param signedAttr table of attributes to be included in signature
* @param unsignedAttr table of attributes to be included as unsigned
*/
public void AddSigner(
AsymmetricKeyParameter privateKey,
byte[] subjectKeyID,
string encryptionOID,
string digestOID,
AttributeTable signedAttr,
AttributeTable unsignedAttr)
{
doAddSigner(privateKey, GetSignerIdentifier(subjectKeyID), encryptionOID, digestOID,
new DefaultSignedAttributeTableGenerator(signedAttr),
new SimpleAttributeTableGenerator(unsignedAttr),
signedAttr);
}
internal SignerInf(
CmsSignedGenerator outer,
ISignatureFactory sigCalc,
SignerIdentifier signerIdentifier,
CmsAttributeTableGenerator sAttr,
CmsAttributeTableGenerator unsAttr,
AttributeTable baseSignedTable)
{
this.outer = outer;
this.sigCalc = sigCalc;
this.signerIdentifier = signerIdentifier;
this.digestOID = new DefaultDigestAlgorithmIdentifierFinder().find((AlgorithmIdentifier)sigCalc.AlgorithmDetails).Algorithm.Id;
this.encOID = ((AlgorithmIdentifier)sigCalc.AlgorithmDetails).Algorithm.Id;
this.sAttr = sAttr;
this.unsAttr = unsAttr;
this.baseSignedTable = baseSignedTable;
}
private Asn1Object GetSingleValuedSignedAttribute(
DerObjectIdentifier attrOID, string printableName)
{
AttributeTable unsignedAttrTable = this.UnsignedAttributes;
if (unsignedAttrTable != null &&
unsignedAttrTable.GetAll(attrOID).Count > 0)
{
throw new CmsException("The " + printableName
+ " attribute MUST NOT be an unsigned attribute");
}
AttributeTable signedAttrTable = this.SignedAttributes;
if (signedAttrTable == null)
{
return(null);
}
Asn1EncodableVector v = signedAttrTable.GetAll(attrOID);
switch (v.Count)
{
case 0:
return(null);
case 1:
Attribute t = (Attribute)v[0];
Asn1Set attrValues = t.AttrValues;
if (attrValues.Count != 1)
{
throw new CmsException("A " + printableName
+ " attribute MUST have a single attribute value");
}
return(attrValues[0].ToAsn1Object());
default:
throw new CmsException("The SignedAttributes in a signerInfo MUST NOT include multiple instances of the "
+ printableName + " attribute");
}
}
public override void Close()
{
Platform.Dispose(_out);
// TODO Parent context(s) should really be closed explicitly
_eiGen.Close();
if (_outer.unprotectedAttributeGenerator != null)
{
AttributeTable attrTable = _outer.unprotectedAttributeGenerator.GetAttributes(Platform.CreateHashtable());
Asn1Set unprotectedAttrs = new BerSet(attrTable.ToAsn1EncodableVector());
_envGen.AddObject(new DerTaggedObject(false, 1, unprotectedAttrs));
}
_envGen.Close();
_cGen.Close();
base.Close();
}
/**
* Return a signer information object with passed in SignerInformationStore representing counter
* signatures attached as an unsigned attribute.
*
* @param signerInformation the signerInfo to be used as the basis.
* @param counterSigners signer info objects carrying counter signature.
* @return a copy of the original SignerInformationObject with the changed attributes.
*/
public static SignerInformation AddCounterSigners(
SignerInformation signerInformation,
SignerInformationStore counterSigners)
{
// TODO Perform checks from RFC 3852 11.4
SignerInfo sInfo = signerInformation.info;
AttributeTable unsignedAttr = signerInformation.UnsignedAttributes;
Asn1EncodableVector v;
if (unsignedAttr != null)
{
v = unsignedAttr.ToAsn1EncodableVector();
}
else
{
v = new Asn1EncodableVector();
}
Asn1EncodableVector sigs = new Asn1EncodableVector();
foreach (SignerInformation sigInf in counterSigners.GetSigners())
{
sigs.Add(sigInf.ToSignerInfo());
}
v.Add(new Attribute(CmsAttributes.CounterSignature, new DerSet(sigs)));
return(new SignerInformation(
new SignerInfo(
sInfo.SignerID,
sInfo.DigestAlgorithm,
sInfo.AuthenticatedAttributes,
sInfo.DigestEncryptionAlgorithm,
sInfo.EncryptedDigest,
new DerSet(v)),
signerInformation.contentType,
signerInformation.content,
null));
}
internal SignerInf(
CmsSignedGenerator outer,
AsymmetricKeyParameter key,
SignerIdentifier signerIdentifier,
string digestOID,
string encOID,
CmsAttributeTableGenerator sAttr,
CmsAttributeTableGenerator unsAttr,
AttributeTable baseSignedTable)
{
string digestName = Helper.GetDigestAlgName(digestOID);
string signatureName = digestName + "with" + Helper.GetEncryptionAlgName(encOID);
this.outer = outer;
this.sigCalc = new Asn1SignatureFactory(signatureName, key);
this.signerIdentifier = signerIdentifier;
this.digestOID = digestOID;
this.encOID = encOID;
this.sAttr = sAttr;
this.unsAttr = unsAttr;
this.baseSignedTable = baseSignedTable;
}
/**
* Return a signer information object with the passed in unsigned
* attributes replacing the ones that are current associated with
* the object passed in.
*
* @param signerInformation the signerInfo to be used as the basis.
* @param unsignedAttributes the unsigned attributes to add.
* @return a copy of the original SignerInformationObject with the changed attributes.
*/
public static SignerInformation ReplaceUnsignedAttributes(
SignerInformation signerInformation,
AttributeTable unsignedAttributes)
{
SignerInfo sInfo = signerInformation.info;
Asn1Set unsignedAttr = null;
if (unsignedAttributes != null)
{
unsignedAttr = new DerSet(unsignedAttributes.ToAsn1EncodableVector());
}
return(new SignerInformation(
new SignerInfo(
sInfo.SignerID,
sInfo.DigestAlgorithm,
sInfo.AuthenticatedAttributes,
sInfo.DigestEncryptionAlgorithm,
sInfo.EncryptedDigest,
unsignedAttr),
signerInformation.contentType,
signerInformation.content,
null));
}
/**
* Return a SignerInformationStore containing the counter signatures attached to this
* signer. If no counter signatures are present an empty store is returned.
*/
public SignerInformationStore GetCounterSignatures()
{
// TODO There are several checks implied by the RFC3852 comments that are missing
/*
* The countersignature attribute MUST be an unsigned attribute; it MUST
* NOT be a signed attribute, an authenticated attribute, an
* unauthenticated attribute, or an unprotected attribute.
*/
AttributeTable unsignedAttributeTable = UnsignedAttributes;
if (unsignedAttributeTable == null)
{
return(new SignerInformationStore(Platform.CreateArrayList(0)));
}
IList counterSignatures = Platform.CreateArrayList();
/*
* The UnsignedAttributes syntax is defined as a SET OF Attributes. The
* UnsignedAttributes in a signerInfo may include multiple instances of
* the countersignature attribute.
*/
Asn1EncodableVector allCSAttrs = unsignedAttributeTable.GetAll(CmsAttributes.CounterSignature);
foreach (Attribute counterSignatureAttribute in allCSAttrs)
{
/*
* A countersignature attribute can have multiple attribute values. The
* syntax is defined as a SET OF AttributeValue, and there MUST be one
* or more instances of AttributeValue present.
*/
Asn1Set values = counterSignatureAttribute.AttrValues;
if (values.Count < 1)
{
// TODO Throw an appropriate exception?
}
foreach (Asn1Encodable asn1Obj in values)
{
/*
* Countersignature values have the same meaning as SignerInfo values
* for ordinary signatures, except that:
*
* 1. The signedAttributes field MUST NOT contain a content-type
* attribute; there is no content type for countersignatures.
*
* 2. The signedAttributes field MUST contain a message-digest
* attribute if it contains any other attributes.
*
* 3. The input to the message-digesting process is the contents
* octets of the DER encoding of the signatureValue field of the
* SignerInfo value with which the attribute is associated.
*/
SignerInfo si = SignerInfo.GetInstance(asn1Obj.ToAsn1Object());
string digestName = CmsSignedHelper.Instance.GetDigestAlgName(si.DigestAlgorithm.Algorithm.Id);
counterSignatures.Add(new SignerInformation(si, null, null, new CounterSignatureDigestCalculator(digestName, GetSignature())));
}
}
return(new SignerInformationStore(counterSignatures));
}
/// <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);
Platform.Dispose(cOut);
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)
{
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));
}
internal SignerInfo ToSignerInfo(
DerObjectIdentifier contentType,
CmsProcessable content,
SecureRandom random)
{
AlgorithmIdentifier digAlgId = DigestAlgorithmID;
string digestName = Helper.GetDigestAlgName(digestOID);
string signatureName = digestName + "with" + Helper.GetEncryptionAlgName(encOID);
byte[] hash;
if (outer._digests.Contains(digestOID))
{
hash = (byte[])outer._digests[digestOID];
}
else
{
IDigest dig = Helper.GetDigestInstance(digestName);
if (content != null)
{
content.Write(new DigOutputStream(dig));
}
hash = DigestUtilities.DoFinal(dig);
outer._digests.Add(digestOID, hash.Clone());
}
IStreamCalculator calculator = sigCalc.CreateCalculator();
#if NETCF_1_0 || NETCF_2_0 || SILVERLIGHT || PORTABLE
Stream sigStr = calculator.Stream;
#else
Stream sigStr = new BufferedStream(calculator.Stream);
#endif
Asn1Set signedAttr = null;
if (sAttr != null)
{
IDictionary parameters = outer.GetBaseParameters(contentType, digAlgId, hash);
// Asn1.Cms.AttributeTable signed = sAttr.GetAttributes(Collections.unmodifiableMap(parameters));
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 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);
}
Platform.Dispose(sigStr);
byte[] sigBytes = ((IBlockResult)calculator.GetResult()).Collect();
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));
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 = Helper.GetEncAlgorithmIdentifier(
new DerObjectIdentifier(encOID), sigX509Parameters);
return(new SignerInfo(signerIdentifier, digAlgId,
signedAttr, encAlgId, new DerOctetString(sigBytes), unsignedAttr));
}
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));
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 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));
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 = Helper.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);
}
}
private bool DoVerify(
AsymmetricKeyParameter key)
{
string digestName = Helper.GetDigestAlgName(this.DigestAlgOid);
IDigest digest = Helper.GetDigestInstance(digestName);
DerObjectIdentifier sigAlgOid = this.encryptionAlgorithm.Algorithm;
Asn1Encodable sigParams = this.encryptionAlgorithm.Parameters;
ISigner sig;
if (sigAlgOid.Equals(PkcsObjectIdentifiers.IdRsassaPss))
{
// RFC 4056 2.2
// When the id-RSASSA-PSS algorithm identifier is used for a signature,
// the AlgorithmIdentifier parameters field MUST contain RSASSA-PSS-params.
if (sigParams == null)
{
throw new CmsException("RSASSA-PSS signature must specify algorithm parameters");
}
try
{
// TODO Provide abstract configuration mechanism
// (via alternate SignerUtilities.GetSigner method taking ASN.1 params)
RsassaPssParameters pss = RsassaPssParameters.GetInstance(
sigParams.ToAsn1Object());
if (!pss.HashAlgorithm.Algorithm.Equals(this.digestAlgorithm.Algorithm))
{
throw new CmsException("RSASSA-PSS signature parameters specified incorrect hash algorithm");
}
if (!pss.MaskGenAlgorithm.Algorithm.Equals(PkcsObjectIdentifiers.IdMgf1))
{
throw new CmsException("RSASSA-PSS signature parameters specified unknown MGF");
}
IDigest pssDigest = DigestUtilities.GetDigest(pss.HashAlgorithm.Algorithm);
int saltLength = pss.SaltLength.Value.IntValue;
byte trailerField = (byte)pss.TrailerField.Value.IntValue;
// RFC 4055 3.1
// The value MUST be 1, which represents the trailer field with hexadecimal value 0xBC
if (trailerField != 1)
{
throw new CmsException("RSASSA-PSS signature parameters must have trailerField of 1");
}
sig = new PssSigner(new RsaBlindedEngine(), pssDigest, saltLength);
}
catch (Exception e)
{
throw new CmsException("failed to set RSASSA-PSS signature parameters", e);
}
}
else
{
// TODO Probably too strong a check at the moment
// if (sigParams != null)
// throw new CmsException("unrecognised signature parameters provided");
string signatureName = digestName + "with" + Helper.GetEncryptionAlgName(this.EncryptionAlgOid);
sig = Helper.GetSignatureInstance(signatureName);
//sig = Helper.GetSignatureInstance(this.EncryptionAlgOid);
//sig = SignerUtilities.GetSigner(sigAlgOid);
}
try
{
if (digestCalculator != null)
{
resultDigest = digestCalculator.GetDigest();
}
else
{
if (content != null)
{
content.Write(new DigOutputStream(digest));
}
else if (signedAttributeSet == null)
{
// TODO Get rid of this exception and just treat content==null as empty not missing?
throw new CmsException("data not encapsulated in signature - use detached constructor.");
}
resultDigest = DigestUtilities.DoFinal(digest);
}
}
catch (IOException e)
{
throw new CmsException("can't process mime object to create signature.", e);
}
// RFC 3852 11.1 Check the content-type attribute is correct
{
Asn1Object validContentType = GetSingleValuedSignedAttribute(
CmsAttributes.ContentType, "content-type");
if (validContentType == null)
{
if (!isCounterSignature && signedAttributeSet != null)
{
throw new CmsException("The content-type attribute type MUST be present whenever signed attributes are present in signed-data");
}
}
else
{
if (isCounterSignature)
{
throw new CmsException("[For counter signatures,] the signedAttributes field MUST NOT contain a content-type attribute");
}
if (!(validContentType is DerObjectIdentifier))
{
throw new CmsException("content-type attribute value not of ASN.1 type 'OBJECT IDENTIFIER'");
}
DerObjectIdentifier signedContentType = (DerObjectIdentifier)validContentType;
if (!signedContentType.Equals(contentType))
{
throw new CmsException("content-type attribute value does not match eContentType");
}
}
}
// RFC 3852 11.2 Check the message-digest attribute is correct
{
Asn1Object validMessageDigest = GetSingleValuedSignedAttribute(
CmsAttributes.MessageDigest, "message-digest");
if (validMessageDigest == null)
{
if (signedAttributeSet != null)
{
throw new CmsException("the message-digest signed attribute type MUST be present when there are any signed attributes present");
}
}
else
{
if (!(validMessageDigest is Asn1OctetString))
{
throw new CmsException("message-digest attribute value not of ASN.1 type 'OCTET STRING'");
}
Asn1OctetString signedMessageDigest = (Asn1OctetString)validMessageDigest;
if (!Arrays.AreEqual(resultDigest, signedMessageDigest.GetOctets()))
{
throw new CmsException("message-digest attribute value does not match calculated value");
}
}
}
// RFC 3852 11.4 Validate countersignature attribute(s)
{
AttributeTable signedAttrTable = this.SignedAttributes;
if (signedAttrTable != null &&
signedAttrTable.GetAll(CmsAttributes.CounterSignature).Count > 0)
{
throw new CmsException("A countersignature attribute MUST NOT be a signed attribute");
}
AttributeTable unsignedAttrTable = this.UnsignedAttributes;
if (unsignedAttrTable != null)
{
foreach (Attribute csAttr in unsignedAttrTable.GetAll(CmsAttributes.CounterSignature))
{
if (csAttr.AttrValues.Count < 1)
{
throw new CmsException("A countersignature attribute MUST contain at least one AttributeValue");
}
// Note: We don't recursively validate the countersignature value
}
}
}
try
{
sig.Init(false, key);
if (signedAttributeSet == null)
{
if (digestCalculator != null)
{
// need to decrypt signature and check message bytes
return(VerifyDigest(resultDigest, key, this.GetSignature()));
}
else if (content != null)
{
// TODO Use raw signature of the hash value instead
content.Write(new SigOutputStream(sig));
}
}
else
{
byte[] tmp = this.GetEncodedSignedAttributes();
sig.BlockUpdate(tmp, 0, tmp.Length);
}
return(sig.VerifySignature(this.GetSignature()));
}
catch (InvalidKeyException e)
{
throw new CmsException("key not appropriate to signature in message.", e);
}
catch (IOException e)
{
throw new CmsException("can't process mime object to create signature.", e);
}
catch (SignatureException e)
{
throw new CmsException("invalid signature format in message: " + e.Message, e);
}
}
