public static SignatureDetails ValidateXMLSignature(string SignedXML)
{
if (SignedXML == null)
{
throw new ArgumentNullException("SignedXML");
}
//Make sure the SAPI Library is loaded
SAPIInit();
SignatureDetails SigDetails = new SignatureDetails();
SigFieldSettings SigFieldSettings = new SigFieldSettings();
SigFieldInfo SignatureFieldInfo = new SigFieldInfo();
SAPICrypt SAPI = new SAPICrypt();
SigFieldHandle hField = null;
int rc;
SESHandle hSession = new SESHandle();
if ((rc = SAPI.HandleAcquire(out hSession)) != 0)
{
throw new Exception(string.Format(
"Memory allocation error (#{0})", rc.ToString("X")));
}
SAPIContext ctxValidateSignature = new SAPIContext();
int num = 0;
if ((rc = SAPI.SignatureFieldEnumInit(hSession, ctxValidateSignature, SAPI_ENUM_FILE_TYPE.SAPI_ENUM_FILE_XML, SignedXML, 0, ref num)) != 0)
{
SAPI.HandleRelease(hSession);
throw new Exception(string.Format(
"An error occured while initializing the signature validation process (#{0})", rc.ToString("X")));
}
if (num < 1)
{
throw new Exception("The XML file is not signed!");
}
if (num > 1)
{
throw new Exception("SAPI only supports a single signature per XML file!");
}
if ((rc = SAPI.SignatureFieldEnumCont(hSession, ctxValidateSignature, out hField)) != 0)
{
SAPI.ContextRelease(ctxValidateSignature);
SAPI.HandleRelease(hSession);
throw new Exception(string.Format(
"Failed to retrieve signature (#{0})", rc.ToString("X")));
}
if ((rc = SAPI.SignatureFieldInfoGet(hSession, hField, SigFieldSettings, SignatureFieldInfo)) != 0)
{
SAPI.ContextRelease(ctxValidateSignature);
SAPI.HandleRelease(hSession);
throw new Exception(string.Format(
"Failed to parse signature details (#{0})", rc.ToString("X")));
}
CertStatus not_used = new CertStatus();
SigDetails.isValid = SAPI.SignatureFieldVerify(hSession, hField, not_used, 0) == 0;
SigDetails.SignerCertificate = new X509Certificate2(
(byte[])(((SAPIByteArray)SignatureFieldInfo.Certificate).ToArray()));
SigDetails.SignerName = SignatureFieldInfo.SignerName;
//Convert FILE_TIME to ticks
ulong filetime = SignatureFieldInfo.SignatureTime.HighDateTime;
filetime <<= 32;
filetime += SignatureFieldInfo.SignatureTime.LowDateTime;
SigDetails.SignatureTimeTicks = DateTime.FromFileTimeUtc((long)filetime).Ticks;
//Cleanup memory
SAPI.ContextRelease(ctxValidateSignature);
SAPI.HandleRelease(hSession);
return(SigDetails);
}