internal static Boolean VerifySignature(PublicKey pubKey, Wincrypt.CERT_SIGNED_CONTENT_INFO signedInfo)
{
Byte[] data = getSignedBytes(signedInfo);
Byte[] signature = pubKey.Oid.Value == "1.2.840.10045.2.1"
? getSignatureBytes(signedInfo, true)
: getSignatureBytes(signedInfo, false);
Oid hashAlgorithm = new Oid(signedInfo.SignatureAlgorithm.pszObjId);
hashAlgorithm = new Oid(hashAlgorithm.FriendlyName.ToLower().Replace("rsa", null).Replace("ecdsa", null));
return(verifySignature(pubKey, data, signature, hashAlgorithm));
}
void getSignature()
{
UInt32 pcbStructInfo = 0;
if (!Crypt32.CryptDecodeObject(65537, Wincrypt.X509_CERT, RawData, (UInt32)RawData.Length, 8, IntPtr.Zero, ref pcbStructInfo))
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
IntPtr pvStructInfo = Marshal.AllocHGlobal((Int32)pcbStructInfo);
Crypt32.CryptDecodeObject(65537, Wincrypt.X509_CERT, RawData, (UInt32)RawData.Length, 8, pvStructInfo, ref pcbStructInfo);
signedData = (Wincrypt.CERT_SIGNED_CONTENT_INFO)Marshal.PtrToStructure(pvStructInfo, typeof(Wincrypt.CERT_SIGNED_CONTENT_INFO));
signature = new Byte[signedData.Signature.cbData];
Marshal.Copy(signedData.Signature.pbData, signature, 0, (Int32)signedData.Signature.cbData);
sigUnused = signedData.Signature.cUnusedBits;
SignatureAlgorithm = new Oid(signedData.SignatureAlgorithm.pszObjId);
Array.Reverse(signature);
Marshal.FreeHGlobal(pvStructInfo);
}
static Byte[] getSignatureBytes(Wincrypt.CERT_SIGNED_CONTENT_INFO signedData, Boolean cng)
{
Byte[] signature = new Byte[signedData.Signature.cbData];
Marshal.Copy(signedData.Signature.pbData, signature, 0, (Int32)signedData.Signature.cbData);
if (cng)
{
Asn1Reader asn = new Asn1Reader(signature);
asn.MoveNext();
List <byte> sigBuilder = asn.PayloadLength % 2 == 1
? new List <Byte>(asn.GetPayload().Skip(1))
: new List <Byte>(asn.GetPayload());
asn.MoveNext();
sigBuilder.AddRange(
asn.PayloadLength % 2 == 1
? asn.GetPayload().Skip(1)
: asn.GetPayload()
);
return(sigBuilder.ToArray());
}
return(signature);
}
static Byte[] getSignedBytes(Wincrypt.CERT_SIGNED_CONTENT_INFO signedData)
{
Byte[] tbs = new Byte[signedData.ToBeSigned.cbData];
Marshal.Copy(signedData.ToBeSigned.pbData, tbs, 0, tbs.Length);
return(tbs);
}
