public PdfPKCS7(byte[] contentsKey) {
Asn1InputStream din = new Asn1InputStream(new MemoryStream(contentsKey));
//
// Basic checks to make sure it's a PKCS#7 SignedData Object
//
Asn1Object pkcs;
try {
pkcs = din.ReadObject();
}
catch {
throw new ArgumentException("can't decode PKCS7SignedData object");
}
if (!(pkcs is Asn1Sequence)) {
throw new ArgumentException("Not a valid PKCS#7 object - not a sequence");
}
Asn1Sequence signedData = (Asn1Sequence)pkcs;
DerObjectIdentifier objId = (DerObjectIdentifier)signedData[0];
if (!objId.Id.Equals(ID_PKCS7_SIGNED_DATA))
throw new ArgumentException("Not a valid PKCS#7 object - not signed data");
Asn1Sequence content = (Asn1Sequence)((DerTaggedObject)signedData[1]).GetObject();
// the positions that we care are:
// 0 - version
// 1 - digestAlgorithms
// 2 - possible ID_PKCS7_DATA
// (the certificates and crls are taken out by other means)
// last - signerInfos
// the version
version = ((DerInteger)content[0]).Value.IntValue;
// the digestAlgorithms
digestalgos = new Hashtable();
IEnumerator e = ((Asn1Set)content[1]).GetEnumerator();
while (e.MoveNext())
{
Asn1Sequence s = (Asn1Sequence)e.Current;
DerObjectIdentifier o = (DerObjectIdentifier)s[0];
digestalgos[o.Id] = null;
}
// the certificates and crls
X509CertificateParser cf = new X509CertificateParser();
certs = new ArrayList();
foreach (X509Certificate cc in cf.ReadCertificates(contentsKey)) {
certs.Add(cc);
}
crls = new ArrayList();
// the possible ID_PKCS7_DATA
Asn1Sequence rsaData = (Asn1Sequence)content[2];
if (rsaData.Count > 1) {
DerOctetString rsaDataContent = (DerOctetString)((DerTaggedObject)rsaData[1]).GetObject();
RSAdata = rsaDataContent.GetOctets();
}
// the signerInfos
int next = 3;
while (content[next] is DerTaggedObject)
++next;
Asn1Set signerInfos = (Asn1Set)content[next];
if (signerInfos.Count != 1)
throw new ArgumentException("This PKCS#7 object has multiple SignerInfos - only one is supported at this time");
Asn1Sequence signerInfo = (Asn1Sequence)signerInfos[0];
// the positions that we care are
// 0 - version
// 1 - the signing certificate serial number
// 2 - the digest algorithm
// 3 or 4 - digestEncryptionAlgorithm
// 4 or 5 - encryptedDigest
signerversion = ((DerInteger)signerInfo[0]).Value.IntValue;
// Get the signing certificate
Asn1Sequence issuerAndSerialNumber = (Asn1Sequence)signerInfo[1];
BigInteger serialNumber = ((DerInteger)issuerAndSerialNumber[1]).Value;
foreach (X509Certificate cert in certs) {
if (serialNumber.Equals(cert.SerialNumber)) {
signCert = cert;
break;
}
}
if (signCert == null) {
throw new ArgumentException("Can't find signing certificate with serial " + serialNumber.ToString(16));
}
CalcSignCertificateChain();
digestAlgorithm = ((DerObjectIdentifier)((Asn1Sequence)signerInfo[2])[0]).Id;
next = 3;
if (signerInfo[next] is Asn1TaggedObject) {
Asn1TaggedObject tagsig = (Asn1TaggedObject)signerInfo[next];
Asn1Set sseq = Asn1Set.GetInstance(tagsig, false);
sigAttr = sseq.GetEncoded(Asn1Encodable.Der);
for (int k = 0; k < sseq.Count; ++k) {
Asn1Sequence seq2 = (Asn1Sequence)sseq[k];
if (((DerObjectIdentifier)seq2[0]).Id.Equals(ID_MESSAGE_DIGEST)) {
Asn1Set sset = (Asn1Set)seq2[1];
digestAttr = ((DerOctetString)sset[0]).GetOctets();
}
else if (((DerObjectIdentifier)seq2[0]).Id.Equals(ID_ADBE_REVOCATION)) {
Asn1Set setout = (Asn1Set)seq2[1];
Asn1Sequence seqout = (Asn1Sequence)setout[0];
for (int j = 0; j < seqout.Count; ++j) {
Asn1TaggedObject tg = (Asn1TaggedObject)seqout[j];
if (tg.TagNo != 1)
continue;
Asn1Sequence seqin = (Asn1Sequence)tg.GetObject();
FindOcsp(seqin);
}
}
}
if (digestAttr == null)
throw new ArgumentException("Authenticated attribute is missing the digest.");
++next;
}
digestEncryptionAlgorithm = ((DerObjectIdentifier)((Asn1Sequence)signerInfo[next++])[0]).Id;
digest = ((DerOctetString)signerInfo[next++]).GetOctets();
if (next < signerInfo.Count && (signerInfo[next] is DerTaggedObject)) {
DerTaggedObject taggedObject = (DerTaggedObject) signerInfo[next];
Asn1Set unat = Asn1Set.GetInstance(taggedObject, false);
Org.BouncyCastle.Asn1.Cms.AttributeTable attble = new Org.BouncyCastle.Asn1.Cms.AttributeTable(unat);
Org.BouncyCastle.Asn1.Cms.Attribute ts = attble[PkcsObjectIdentifiers.IdAASignatureTimeStampToken];
if (ts != null) {
Asn1Set attributeValues = ts.AttrValues;
Asn1Sequence tokenSequence = Asn1Sequence.GetInstance(attributeValues[0]);
Org.BouncyCastle.Asn1.Cms.ContentInfo contentInfo = Org.BouncyCastle.Asn1.Cms.ContentInfo.GetInstance(tokenSequence);
this.timeStampToken = new TimeStampToken(contentInfo);
}
}
if (RSAdata != null || digestAttr != null) {
messageDigest = GetHashClass();
}
sig = SignerUtilities.GetSigner(GetDigestAlgorithm());
sig.Init(false, signCert.GetPublicKey());
}
