Tagged Questions
5
votes
5answers
153 views
A standard way to manually add a digital signature to a pdf file?
I've created a few certificates to use myself, but I find myself stumped when it comes to creating a certificate which contains a digital signature. First, how would I go about creating a standard ...
3
votes
1answer
258 views
Enhanced Key Usage vs. Extended Key Usage
I've seen both the terms Enhanced Key Usage and Extended Key Usage, and both were abbreviated as EKU. Do both refer to the same extension or property?
4
votes
1answer
146 views
Why do X.509 certificates have “Key Usage” attribute?
I can find their values and all details in the RFC, but I cannot find why it was decided to have this attribute in certificates, instead of leaving them to be multipurposes.
Is there a reasoning ...
4
votes
1answer
114 views
Which properties of a X.509 certificate should be critical and which not?
RFC5280's section 4.2 states
Each extension in a
certificate is designated as either critical or non-critical. A
certificate-using system MUST reject the certificate if it encounters
...
1
vote
1answer
111 views
How to troubleshoot why Thunderbird rejects a PKCS#12 certificate with “Could not verify this certificate for unknown reasons”?
After playing around a bit with openssl, I created a PKCS12 certificate which imports flawlessly in Firefox while Thunderbird "Could not verify this certificate for unknown reasons". Talk about a ...
4
votes
1answer
295 views
How to set up OpenSSH to use x509 PKI for authentication?
I do not mean simply putting the public RSA key of a x.509 certificate into ~/.ssh/authorized_keys - I'm looking for a way to set up a ssh such that x.509 certificates signed by a pre-defined CA will ...
0
votes
1answer
109 views
Behavior when validating an expired certificate chain
I have the following situation:
A server certificate (CServ) is signed by self-signed certificate (C0)
A client certificate (CCli) is signed by CServ
Client's trust-store contains C0, so the client ...
4
votes
2answers
203 views
Extensions for SSL server certificate
I have some question about the X.509 v3 extensions. What extensions should appear in a proper certificate for a SSL server ?
2
votes
1answer
76 views
how does OpenSSL create X.509 certs from SPKACs?
The SPKAC ASN.1 description:
PublicKeyAndChallenge ::= SEQUENCE {
spki SubjectPublicKeyInfo,
challenge IA5STRING
}
SignedPublicKeyAndChallenge ::= SEQUENCE {
publicKeyAndChallenge ...
2
votes
2answers
141 views
distribution mechanisms for CRLs
From the X.509 RFC:
DistributionPoint ::= SEQUENCE {
distributionPoint [0] DistributionPointName OPTIONAL,
reasons [1] ReasonFlags OPTIONAL,
cRLIssuer ...
4
votes
1answer
156 views
where to download revoked certificates from
I don't want the certificate revocation lists - I want actual full on revoked certificates for test purposes.
For example, Flame used a signed rogue cert and in 2001 someone posed as Microsoft and ...
5
votes
1answer
179 views
Which attributes of a X509v3 certificate are never really used?
Are there any extensions/extended key usage attributes of a X.509Certificate that are rarely or never used in practice?
Either due to never being part of an issued certificate or because they are ...
3
votes
1answer
148 views
What are the Netscape Cert Type attributes? Why/when are they needed?
What are the Netscape Cert Type attributes in a X.509 Certificate and how are they different with the X509v3 extensions?
Example:
There is the Client/Server Extended Key Usage (X.509) but there is ...
5
votes
2answers
141 views
ASN.1: ENUMERATED vs INTEGER
From the X.509 specs:
CRLReason ::= ENUMERATED {
unspecified (0),
keyCompromise (1),
cACompromise (2),
affiliationChanged (3),
...
1
vote
1answer
74 views
What keys are involved in an X.509 certificate?
I'm trying to examine some instances where an X.509 certificate uses public and private keys for a paper I'm going to write. However, the only thing I have explicitly seen so far is in one of the ...
3
votes
2answers
412 views
x.509 CRLs: next update?
An X.509 certificate revocation list contains a field specifying when the next such list is expected to be issued. I'm trying to figure out the importance of this field...I know that sometimes ...
4
votes
4answers
735 views
Can an intermediate CA be trusted like a self-signed root CA?
Is it possible within the limits of the X.509 specification to mark an intermediate CA as trusted for a specific purpose, e.g. to verify a VPN, HTTPS etc. server key, just like it would work with a ...
3
votes
1answer
534 views
how do extended validation X.509 certs work?
https://www.forumatic.com/ uses an extended validation cert. wikipedia.org's entry on extended validation certs says that a cert is known to be an extended validation cert if the OID in the ...
0
votes
1answer
297 views
URIs in the subjAltName X.509 extension
The subjAltTag extension for X.509 certificates can take in domain names, email addresses, URIs, etc. I was playing around with an X.509 whose subjAltTag had just a URI in it doesn't seem to work. ...
2
votes
3answers
299 views
why does the first certificate have a RSA public key in x.509?
Example from http://en.wikipedia.org/wiki/X.509#Extensions_informing_a_specific_usage_of_a_certificate
1st certficate - freesoft
2nd - CA thawte
Don't we use the RSA public key from the 2nd ...
1
vote
1answer
84 views
valid intermediate certs not in browser
Say an X.509 cert is signed by an intermediate cert that's not in your browser. Maybe the root certificate is but not the intermediate cert. At that point it seems like a valid certification path ...
7
votes
2answers
281 views
X.509 certificate policies question
I asked another question about certificate policy mappings. This is a different issue. This is about Certificate Policies.
To quote from the X.509 RFC:
In an end entity certificate, these ...
1
vote
1answer
205 views
X.509 certificate policy mapping question
So I'm a little confused how X.509 certificate policy mappings work. So let's say the following depicts my cert chain:
root CA ---> intermediary CA ---> client cert
Would the root CA have a ...
4
votes
2answers
235 views
How are possible uses for X.509 (SSL) certificates denoted?
X.509 certificates can be used for servers, clients, email, code signing and more applications. http://twitpic.com/6gdxaq indicates that a certificate can have different of these 'capabilities' on it ...
