2
votes
2answers
50 views

The reason to insert Subject Alternative Names into CA certificate

I am trying to understand meaning of the Subject Alternative Name extension. The reason of usage it in SSL X.509 certificates or other end-entities certificates is mostly clear for me. However, I ...
1
vote
1answer
82 views

Self-signing client certificates and distributing them, is the following a sound procedure?

I have a case at hand as follows: There is a number of clients in Internet (i.e. untrusted channel), initially in hundreds but growing in numbers. There is a server doing processing related to these ...
1
vote
1answer
89 views

How to safely renew user and CA certificates in a PKI

I am currently developing my own PKI where x.509-client-certificates are issued by a public server. At the moment, the CA-public key is distributed with the binary and there are no routines for ...
0
votes
2answers
52 views

determine X.509 certificate class

I am very familiar with OpenPGP but don't even use X.509 / S/MIME. I know that there are several classes for certificates (from email check to personal ID check). I would like to know how you ...
0
votes
2answers
54 views

How to encode a username in PKIX certificate?

I was reading through RFC 5280, PKIX Certificate and CRL Profile, Section 4.2.1.6, Subject Alternative Name: The subject alternative name extension allows identities to be bound to the subject ...
0
votes
4answers
132 views

Can a certification authority sign another CA's certs?

Disclaimer: I have low knowledge of X.509 and PKI, so I would appreciate an answer that is not entirely technical, i.e. by using real-life example scenarios.) I was searching for information ...
5
votes
1answer
375 views

Is is typical to create both x509 and OpenPGP key pairs?

I'm looking into increasing my use of signed and encrypted "things" - LibreOffice Documents, Off-the-record chat, PDFs, emails, etc. I'm finding that some things only support x509 format-certificates, ...
4
votes
1answer
244 views

How is an Authenticode timestamp verified?

For an Authenticode signed file to be verifiable by Windows after the original signing certificate has expired (typically 1-3 years after issue), the file also needs to have a cryptographically signed ...
0
votes
1answer
222 views

SSL (TLS v1.2) - Can i offer fallback CAs when upgrading Certificates? (Java)

I am currently developing a product that involves two network situations. At the client side, multiple computers form a P2P network (multiple locations, multiple p2p networks), and a subset of nodes ...
1
vote
3answers
397 views

accepted naming convention for public keys/certificates

Is there an accepted naming convention for referring to PKI artifacts? There seems to be a lot of confusion with naming of artifacts. For example, it seems that some people refer to: public keys ...
7
votes
5answers
3k 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
3k 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?
7
votes
1answer
1k 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 ...
7
votes
1answer
2k 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
444 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 ...
9
votes
2answers
4k 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
504 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
3k 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
171 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
586 views

distribution mechanisms for CRLs

From the X.509 RFC: DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer ...
4
votes
1answer
268 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
407 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
1k 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 ...
6
votes
2answers
576 views

ASN.1: ENUMERATED vs INTEGER

From the X.509 specs: CRLReason ::= ENUMERATED { unspecified (0), keyCompromise (1), cACompromise (2), affiliationChanged (3), ...
1
vote
1answer
135 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
2k 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 ...
5
votes
4answers
2k 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
2k 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
705 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
733 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
108 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 ...
8
votes
2answers
606 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 ...
2
votes
1answer
521 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
3answers
618 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 ...