crl embedded inside document
Is there a way to differentiate If the crl information is embedded inside the pdf document or not ... which is an indicator if the document is LTV enabled or not?
i uploaded 2 files pdf one with ltv enable and has crl embeded in document pdf but It only works on customer environment . and the other file without crl embeded
the two files the same but with different size because one embeded crl and the other not embeded crl
Attachment: 2pdf_files_one_has_ltv_and_the_other_one_without_ltv_66602e5b.zip
Thanks for your previous reply (including LTV information in next release)
Kindly find this updated document which includes LTV and Timestamp embedded using code provided by syncfusion team in last reply in this ticket https://www.syncfusion.com/forums/172460/digital-signature-algorithm
We hope the next release allows us to get the following LTV information (Document is LTV enabled .... shown by adobe reader that OCSP/CRL is embedded & has a timestamp embedded)
Thanks to confirm.
Attachment: 2pdf_files_one_has_ltv_and_the_other_one_without_ltv_d96020ec.zip
Hi David,
We have support to validate the digital signatures in an existing PDF document. Form that, we can able to get time stamp information from the digital signatures.
Please refer to the below UG documentation below,
For example,
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If the signature embedded timestamp information
Please refer to the below code to get time stamp information from the digital signature.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
List<PdfSignatureValidationResult> results;
bool isValid = loadedDocument.Form.Fields.ValidateSignatures(out results);
if(results[0].TimeStampInformation !=null) { if(results[0].TimeStampInformation.IsDocumentTimeStamp) { //A signature is a document timestamp signature } else { //If the TimeStampInformation is not nullable, then it means digital signatures include an embedded timestamp } } else { //Digital Signature does not have timestamp information } |
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If the document is signed with timestamp alone
Please refer to the code to get document timestamp signature from the digital signature.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
List<PdfSignatureValidationResult> results;
bool isValid = loadedDocument.Form.Fields.ValidateSignatures(out results);
if(results[0].TimeStampInformation !=null) { if(results[0].TimeStampInformation.IsDocumentTimeStamp) { //A signature is a document timestamp signature } else { //If the TimeStampInformation is not nullable, then it means digital signatures include an embedded timestamp } } else { //Digital Signature does not have timestamp information } |
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If the signature does not have timestamp information,
Please refer to the code to identify the digital signature have timestamp information or not.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
List<PdfSignatureValidationResult> results;
bool isValid = loadedDocument.Form.Fields.ValidateSignatures(out results);
if(results[0].TimeStampInformation !=null) { if(results[0].TimeStampInformation.IsDocumentTimeStamp) { //A signature is a document timestamp signature } else { //If the TimeStampInformation is not nullable, then it means digital signatures include an embedded timestamp } } else { //Digital Signature does not have timestamp information } |
As we said earlier, we have considered this as a feature request with “Support to get the LTV, CRL & OCSP embed information detail from PdfSignatureValidationResult“. We will implement this support and include this feature in our upcoming 2022 Volume 2 main release, which will be expected at end of June 2022 tentatively.
Please use the below feedback link to track the status of this feature.
https://www.syncfusion.com/feedback/31805/support-to-get-the-detail-of-the-signatures-validity-from
Regards,
Irfana J.
Thank you for the new features, we have tested them.
please check our below comments.
IsCrlEmbedded is working correctly (true when crl is embedded otherwise false)
IsOcspEmbedded is not working correctly (true when crl is embedded otherwise false) not ocsp
IsLtvEnabled is not working correctly (always false).
we found another property in PdfLoadedSignatureField non-public members" isLTVEnabled" that existed in previous releases and it is working fine with us.
we can access it using System.Reflection
Dim highlightedItemProperty As Reflection.PropertyInfo = SignatureField.Signature.GetType().GetProperties(Reflection.BindingFlags.NonPublic Or Reflection.BindingFlags.Instance).Single(Function(pi) pi.Name = "IsLTVEnabled")
Dim isLtvEnabledValReflection As String = highlightedItemProperty.GetValue(SignatureField.Signature, Nothing)
Check images below and check attached pdf files we have used .
test-signed_LTV_CRL_OCSP_False.pdf (LTV/CrlEmbedded/OcspEmbedded should be all false)
test-signed_LTV_CRL_True.pdf (LTV/CrlEmbedded should be true & OCSPEmbedded false)
Attachment: PDF_Files_a9b1d0e6.zip
Hi David,
We have confirmed that the provided file “test-signed_LTV_CRL_True.pdf”
contains OCSP embedded in it. So, the value retrieved in the API
“IsOcspEmbedded” is as expected.
The internal API “IsLTVEnabled” in the Signature field only checks if the DSS entry is present and returns a Boolean. Whereas the public API “IsLtvEnabled” in LtvVerificationInfo verifies the OCSP and CRL byte data present in the DSS entry and returns the Boolean.
Currently we are analyzing the LTV returned false behavior for the file “test-signed_LTV_CRL_True.pdf”, We will provide further analysis details on July 25, 2022.
Regards,
Irfana J.
Thank you for this feedback , we are waiting for LTV fix,
regarding the file “test-signed_LTV_CRL_True.pdf” yes we found that it contains OCSP embedded in it on this Highlighted path
