I'm using pyOpenSSL 17.5.0 to perform certificate chain verification, and I also want to verify if the requested domain name matches the SAN provided in X509Extension.
My current thoughts are to extract DNS list from extensions and perform a regex mapping manually. But shouldn't the pyOpenSSL library to provide this function? I can't find anything useful in its documents...
Related
I want to offer the user the option to sign a PDF by using a digital certificate.
Administration nowadays provide you with a certificate that you can use to sign in their gob related sites and also to sign PDF documents.
I know how to sign a document by using FPDI library, but I do require the certificate file first.
I guess I can always request them to upload the certificate itself as a normal file, but that wouldn't make much sense, as they would also require to share their certificate password (if any) with me.
I would like my site to pop up something like the below to get their signature / certificate - is that possible?
Can I use Let's Encrypt to generate SSL Certificate even if I don't own the domain name? The scenario is I have a site that lets user create their own sort of page inside my site which would be a subdomain under my main domain. Now, there's a feature that they can use their own domain name (using a different provider) that will point to the created page on my site so they can use any domain name that they want.
Will I still be able to provide SSL using Let's Encrypt to my user? Note: I'm new at this thing so I am not sure if I am asking the correct question, but I am asking as how I understand it right now.
Yes.
The validation occurs based on HTTP file retrieval or via DNS through TXT records.
I built Greenlock to be able to handle exactly that kind of use case. It will currently work for the scenario that you suggest and I plan to implement more DynDNS support in the future.
I currently access Google Sheets using the Node module edit-google-spreadsheet, which takes as one of the authentication options, an email address and a PEM file (converted/encrypted P12 file?), which doesn't require input from the user (typical OAuth flow).
I'd like to do the same in Ruby, but I can't find a way to do it. This is a service account accessing a configuration document, it's not applicable to have a user going through an OAuth flow.
Can anyone give me some guidance here?
Thanks!
I'm working on a .NET PDF signature application that allows signing with a SmartCard (Belgian ID). In addition, I'd like the signature to support LTV.
I've followed the instructions and examples from iText, and it seems to work well. Acrobat Reader DC indicates that the signature is valid, and offers LTV.
There is an practical issue however: the included CRL is too big. 14MB on my test ID. This means that, for every signature, 14MB needs to be downloaded which slows down operation and significantly increases the file size of each signed PDF.
I was wondering if there is an alternative to including the complete CRL while still supporting LTV? It seems a bit overkill to include the complete CRL while the only "thing" that seems needed is the inclusion of a verifyable proof that the certificates in the chain have not been revoked at time of signing. I thought that use of the OCSP might offer such functionality, however simply removing the CRL and including a OcspClientBouncyCastle instance didn't do the trick. Is the OCSP that is given to SignDetached used to check whether the certificate is revoked at time of signing instead?
A related question concerns the LTV "support" itself. As I mentioned, Acrobat Reader only indicates that the file supports LTV when the CRL is included. Checking at the online service http://dss.nowina.lu/validation (EU reference) seems to indicate something else however. There, even the file without the embedded CRL has a valid check behind the description "Is AdES-T validation conclusive?" (which is the only checkpoint under "Long Term Validation Data"). As such, I was wondering if it is even needed to include the CRL for LTV?
Suffice to say I'm confused :).
Btw, 2 more warnings from that same verification service that I can't seem to solve: "The 'issuer-serial' attribute is absent or does not match!" and "The signer's certificate is not supported by SSCD!". But maybe thats for another question.
Thanks in advance for any help.
I had a look at your sample document. It does not conform to any LTV profile, merely to T-Level, i.e. it is timestamped.
In detail
The PDF signature is implemented merely by embedding a single CMS container using subfilter ETSI.CAdES.detached which contains
the certificate chain of the signer certificate in the CMS container certificate set
C=BE,CN=Belgium Root CA2
C=BE,CN=Citizen CA,SERIALNUMBER=201103
C=BE,CN=Donny Tytgat (Signature),SURNAME=Tytgat,GIVENNAME=Donny Geert,SERIALNUMBER=81032305309);
a signed Adobe RevocationInfoArchival attribute containing a single good OCSP response for the signer certificate; the response is signed by
CN=Belgium OCSP Responder,C=BE
which has the id-pkix-ocsp-nocheck extension;
a signature time stamp signed by
C=BE,SERIALNUMBER=2014,O=Belgium Federal Government,CN=Time Stamping Authority
Thus, the signature conforms to Baseline T-Level as
A PAdES signature conformant to T-Level shall be a signature conformant to B-Level for which a Trust Service
Provider [i.4] has generated a trusted token (time-mark or time-stamp token) proving that the signature itself actually
existed at a certain date and time.
(section 7 - Requirements for T-Level Conformance - ETSI TS 103 172 V2.2.2)
where B-Level conformance is defined as
This clause defines requirements that PAdES signatures claiming conformance to the B-Level have to fulfil.
The current clause specifies compliance requirements for short-term electronic signatures.
This clause actually profiles
PAdES-BES (signatures that do not incorporate signature-policy-identifier) and PAdES-EPES (signatures
that do incorporate signature-policy-identifier) signatures.
(section 6 - Requirements for B-Level Conformance - ibidem)
(Additional requirements also are fulfilled.)
It does not conform to LT-Level which requires:
The generator shall include the full set of revocation data (CRL or OCSP responses) that have been used in the
validation of the signer, and CA certificates used in signature. This set includes all certificate status
information required for validating the signing certificate, for validating any attribute certificate present in the
signature, and for validating any time-stamp token's signing certificate (i.e. a TSA certificate) already
incorporated to the signature.
(section 8 - Requirements for LT-Level Conformance - ibidem)
as there is no revocation information concerning the CA certificate or the TSA certificate.
Thus, it can also not conform to LTA-Level as
A PAdES signature conformant to LTA-Level shall be a signature conformant to LT-Level to which one or more
document-time-stamp has been incorporated
Concerning other questions
I was wondering if there is an alternative to including the complete CRL while still supporting LTV? It seems a bit overkill to include the complete CRL while the only "thing" that seems needed is the inclusion of a verifyable proof that the certificates in the chain have not been revoked at time of signing. I thought that use of the OCSP might offer such functionality
Given an appropriate PKI infrastructure that is possible. Unfortunately, though, neither the CA not the TSA certificate contain information on a OCSP responder responsible for them. Thus, either the Belgium citizen PKI does not provide OCSP services for those certificates or it merely does not make that provision public.
BTW, this is what the Diagnostic Tree remarks
<Message Id="0">OSCP Uri not found in certificate meta-data !</Message>
are about which you get when verifying your signature using the http://dss.nowina.lu/validation service.
There, even the file without the embedded CRL has a valid check behind the description "Is AdES-T validation conclusive?" (which is the only checkpoint under "Long Term Validation Data").
This user interface layout has misled you, as mentioned above there are more requirements for LTV-related profiles.
I would like to verify a signed executable. The requirement is to validate that the executable itself is valid and where it came from (probably from the subject of the cert). The cert type is PKCS.
I found a similar posting here,
Validate Authenticode signature on EXE - C++ without CAPICOM
The Microsoft documentation, among others, appears to point to CertGetCertificateChain, but the examples tend to work with certificates that are in a store. Does anyone know how to validate a signed executable using CertGetCertificateChain and related API's?
I asked this question some time ago. I had your exact requirements. There's sample code in there that will help you. Have fun!!
Can you elaborate? the question you linked to seems to provide all of the answers you should need.
You state that "the examples tend to work with certificates that are in a store", which I take to mean that the executable needs to be signed with a certificate that chains to a root certificate in the machine's trusted store.
This is true; there's no way around that, otherwise there is no way way to trust that the signer is who he says he is, and no way for the provider to revoke the certificate if it's being fraudulently used.
So, WinVerifyTrust is the right way to validate a signed executable. It's a terrible API so be careful. CryptQueryObject and related apis will give you more information such as the name of the person or company that the certificate was issued to.