if (certificate.PrivateKey is RSACryptoServiceProvider)
{
RSACryptoServiceProvider rsa = (RSACryptoServiceProvider)certificate.PrivateKey;
// Modified by J. Arturo
// Workaround for SHA-256 and SHA-512
if (rsa.CspKeyContainerInfo.ProviderName == "Microsoft Strong Cryptographic Provider" ||
rsa.CspKeyContainerInfo.ProviderName == "Microsoft Enhanced Cryptographic Provider v1.0" ||
rsa.CspKeyContainerInfo.ProviderName == "Microsoft Base Cryptographic Provider v1.0")
{
string providerName = "Microsoft Enhanced RSA and AES Cryptographic Provider";
int providerType = 24;
Type CspKeyContainerInfo_Type = typeof(CspKeyContainerInfo);
FieldInfo CspKeyContainerInfo_m_parameters = CspKeyContainerInfo_Type.GetField("m_parameters", BindingFlags.NonPublic | BindingFlags.Instance);
CspParameters parameters = (CspParameters)CspKeyContainerInfo_m_parameters.GetValue(rsa.CspKeyContainerInfo);
var cspparams = new CspParameters(providerType, providerName, rsa.CspKeyContainerInfo.KeyContainerName);
cspparams.Flags = parameters.Flags;
using (var rsaKey = new RSACryptoServiceProvider(cspparams))
{
// use rsaKey now
}
}
else
{
// Use rsa directly
}
}
Calendar cal = Calendar.getInstance();
PdfPKCS7 pk7 = new PdfPKCS7(key, chain, null, "SHA1", null, false);
MessageDigest messageDigest = MessageDigest.getInstance("SHA1");
byte[] buf = new byte[8192];
int n;
InputStream inp = sap.getRangeStream();
while ((n = inp.read(buf)) > 0) {
messageDigest.update(buf, 0, n);
}
byte[] hash = messageDigest.digest();
byte[] sh = pk7.getAuthenticatedAttributeBytes(hash, cal);
pk7.update(sh, 0, sh.length);
byte[] sg = pk7.getEncodedPKCS7(hash, cal);