Tagged Questions

3
votes
1answer
67 views

Design of system based on HTTPS, Client Certificates and custom CA

I have the following system: 2 application servers. At the beginning is installed the first server and later is installed the second one. A client access from a browser to both servers Application ...
5
votes
5answers
195 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 ...
10
votes
2answers
188 views

What does having an internal two-tier PKI protect against?

There are a lot of Best Practice documents that recommend having an offline Root CA and an Enterprise Subordinate CA that is signed by the root, for an internal Microsoft AD Certificate Services ...
3
votes
2answers
109 views

Why are SSL certificates valid only from a certain date?

Each SSL certificate is valid starting from a specific date and up to the expiration date. What's the point in that "valid from" date? Why do we want a certificate to only be valid after a specific ...
1
vote
1answer
68 views

How to have Thunderbird include a root certificate?

An eMail signed via S/MIME also contains the X.509 certificate chain containing the public key in order to directly verify the signature (assuming its issuing CA is deemed trustworthy). The chain does ...
3
votes
1answer
164 views

Internal CA for Digital Signature Solution - PKI Based

I'm trying to set up a digital signature solution which would work with a internal PKI. We have considered Microsoft Certificate Services, but we don't want to rule out any other option to set up a ...
41
votes
10answers
3k views

Why do we not trust an SSL certificate that expired recently?

Every SSL certificate has an expiration date. Now suppose some site's certificate expired an hour ago or a day ago. All the software by default will either just refuse to connect to the site or issue ...
3
votes
4answers
594 views

Is it possible to create a self signed certificate authority?

Would it be possible to create a legitimate certificate with the CA bit set? I dont have a usecase associated with this, I'm merely curious. To explain my question : Suppose I sign a public ...
1
vote
1answer
196 views

How does a developer interact with Microsoft Certificate *Web Services*

Microsoft Certificate Web Services is a HTTPS web service (WS-Trust) that has no Kerberos dependency and can be used on a variety of devices. This is new in Windows 2008 and is separate from the ...
2
votes
1answer
152 views

What damage could be done if a malicious certificate had an identical “Subject Key Identifier”?

I'm looking at the the Subject Key Identifier attribute of a CA certificate and am trying to understand the role it plays in validation and infer how validating client software could get it wrong. ...
2
votes
1answer
60 views

Is it a good idea to generate certificate-specific CRLs? What is this technique called?

Suppose I create 3 certificates with the following CRLs Cert1 http://crl.server.com/batch1/root1.crl Cert2 http://crl.server.com/batch2/root2.crl Cert3 ...
2
votes
1answer
224 views

What should a CRL file name look like when “new” and “delta” CRLs are generated?

I suspect my Windows 20012 Certificate Server CRL revocation configuration is incorrect every time I generate a new CRL or a new Delta, only a maximum of 3 files are generated. When I created the ...
2
votes
1answer
184 views

What Enhanced Key Usages are required for PKI infrastructure tasks? (OIDs for OSPF and CRL signing, etc)

I'm building a constrained PKI that specifies EKUs for the the entire hierarchy and want to document the OIDs required for PKI tree maintenance tasks. I understand that clients may not validate the ...
3
votes
2answers
303 views

Is an AIA or CRL useful / required at the Root CA if that Root is used to cross certify another PKI?

Suppose I have several independent PKIs that are used Two internal PKIs: One with SHA1 support the other with Suite B algorithms. A partner who I trust and have a policy map with. Since both my ...
2
votes
1answer
286 views

What OID Issuance Policies are appropriate for SmartCard and Browser Certificates?

I'm investigating issuance policies for SMIME and Browser certificates with different levels of assurance. For the purposes of S/MIME and Browser certificates, should I even use an assurance policy? ...
1
vote
2answers
232 views

Self-signed certificates usage for code signing purposes

if a self-signed certificate is trusted by the client's certificate store, then it should be fine to be used, since the client trusts the issuer of the certificate as it does any other trusted CA ...
120
votes
7answers
7k views

How do certification authorities store their private root keys?

Knowledge of a CA private key would allow MitM attackers to transparently supplant any certificates signed by that private key. It would also allow cyber criminals to start forging their own trusted ...
4
votes
1answer
546 views

AIA/CRL locations for Offline Root

I've read the answer to the following "Checklist on building an Offline Root & Intermediate Certificate Authority (CA)" and I have one questions based on the system I am trying building It's an ...
2
votes
2answers
162 views

distribution mechanisms for CRLs

From the X.509 RFC: DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer ...
11
votes
4answers
462 views

What alternatives are there to the existing Certificate Authority system for SSL?

Whilst the current CA system works very well for a lot of people, it does put a lot of power into individual CAs' hands, and makes a CA hack potentially devastating for customers and business. What ...
2
votes
1answer
85 views

Which .CER file format is more secure for purposes of an AIA record?

What file format is most appropriate or secure for the AIA record in a PKI certificate? The options I'm aware of are: DER encoded binary X.509 (.cer) Base-64 encoded X.509 (.cer) I also have the ...
4
votes
3answers
652 views

How is an X509 certificate signer verified?

Lets say I create a self-signed certificate A and use it to issue certificate B. I put certificate A in my trusted root authorities so that all certificates signed by it are accepted. My question is, ...
4
votes
5answers
492 views

Is Spoofing a CA signed certificate possible?

I had never thought about this situation before, I may be completely wrong but I am going to have to clarify it anyway. When a communication starts with a server, during the client handshake, the ...
10
votes
4answers
1k views

Are there technical disadvantages in using free ssl certificates?

Note this question is related, except this one is about free SSL certs. There are providers who are offering totally free entry-level SSL certs (like StartSSL). I was wondering if they are ...
2
votes
1answer
99 views

Curious about best start for autoresponding Certificate Authority (CA)

I am just getting started trying to implement some internal PKI ideas, where my app would need a cert to 'sign' messages. Since this is all completly internal, we have some degree of trust, and I ...
3
votes
4answers
2k views

How are Chrome and Firefox validating SSL Certificates?

How are Chrome and Firefox validating SSL Certificates? Are they requesting data from an SSL certification website, like GeoTrust, to validate the certificate received from the web server?
4
votes
4answers
815 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 ...
2
votes
2answers
82 views

Does it make sense that OCSP returns state for the signer CA itself

I have seen an implementation that in signature verification time searches for OCSP responses signed by the CA validating the status of the CA itself, so my question is if somewhere (maybe RFC2560) ...
4
votes
1answer
2k views

What is updated with “Update Root Certificates” enabled? What is the equivalent in Windows 2008R2?

What root certificates are/are not updated when the following checkbox is checked? Additional questions If I manually remove a root certificate, will this service replace that very certificate? ...
1
vote
3answers
459 views

What is the most secure way to do OCSP signing without creating validation loops?

I'd like to enable the most secure OCSP validation that Windows 2008 SP1 and newer support. Based on the following information, am I required to implement id-pkix-ocsp-nocheck on my OCSP ...
1
vote
1answer
326 views

What are attribute certificates? Why would someone partition a certificate by reason codes?

In "How Certificate Revocation Works" a brief mention of Attribute Certificate and Reason Code partition is made: If validated by a client that supports partitioned and indirect CRLs, the IDP ...
4
votes
1answer
444 views

Can a certificate have multiple chains and multiple self-signed roots?

The following MSFT document has this paragraph: All possible certificate chains are built using locally cached certificates. If none of the certificate chains ends in a self-signed ...
8
votes
2answers
4k views

Checklist on building an Offline Root & Intermediate Certificate Authority (CA)

Microsoft allows a CA to use Cryptography Next Generation (CNG) and advises of incompatibility issues for clients that do not support this suite. Here is an image of the default cryptography settings ...
2
votes
4answers
1k views

What web browsers support OCSP stapling? Are the privacy and performance features the same?

OCSP stapling decreases the load on a PKI infrastructure's OCSP server by attaching a signed OCSP response to the target in a TLS connection. In addition it creates a more secure/private session ...
12
votes
3answers
9k views

Expired SSL Certificate Implications

What are the security implications of an expired SSL certificate? For example if an SSL certificate from a trusted CA has expired will the communication channel continue to remain secure?
13
votes
4answers
4k views

how digital signature verification process works

I am not able to understand that how the digital signature is verified. I know that digital signature will be attached to the message and sent by sender to receiver. then receiver uses the public key ...
3
votes
2answers
402 views

How practical is a certificate's “basic constraint” property in protecting my HTTPS / SSL session?

Suppose a leaf node creates a certificate for a different domain, acting as a CA. Do most popular frameworks, or SSL chain validation tools verify the constraints? Are there any I should be ...
6
votes
3answers
148 views

Guarding against rogue certificates

There has been a lot of news recently about certificates being falsely issued (due to the issuing authority having poor system security!). Apparently the targeted users were mostly Iranians, but it's ...
10
votes
3answers
424 views

Multiple CAs signing a single Cert/CSR?

Just saw this suggested on Slashdot So I've seen quite a few people wanting a switch to self-signed certs (who IMO mostly don't understand what making that secure actually involves), and an idea ...
16
votes
3answers
1k views

What happens when an Intermediate CA is revoked?

Currently I'm working on a certificate manager that allows our product to securely connect to remote webservices (over TLS/SSL). For security, we use Certificate Revocation List checking (or ...
6
votes
2answers
388 views

security of PKI, Certificates, certificate authorities, forward secrecy

I want to understand how certificates add to the security of information exchange. Suppose i have a encrypted bidirectional connection between Alice and Bob, using a public key/private key pair. As ...
7
votes
1answer
551 views

Moving from a one tier to a two tier Microsoft Certificate Authority hierachy

Right now we have a single Microsoft Enterprise Root CA which issues certificates to our VPN users for two factor authentication. We're planning to extend use of the CA to issue certificates for RDP ...
8
votes
1answer
1k views

Renewing Microsoft Certificate Services Root Certificate

We currently have Microsoft Enterprise Certificate Server installed on a domain member machine which issues 1 year certificates to users for authenticating to VPN. We'd like to start issuing web ...
7
votes
3answers
1k views

Certificate authorities for a PKI

Some people think the certificate authorities for a PKI should be the government, but others think certificate authorities should be private entities, such as banks, corporations, or schools. What are ...
19
votes
11answers
2k views

How feasible is it for a CA to be hacked? Which default trusted root certificates should I remove?

This question has been revised & clarified significantly since the original version. If we look at each trusted certificate in my Trusted Root store, how much should I trust them? What factors ...
0
votes
2answers
176 views

Create a certificate signing request [closed]

can someone please tell me a few tools that can be used to create a CSR ?
2
votes
2answers
2k views

What is an intermediate certificate authority?

What is meant by an "intermediate certificate authority?"
7
votes
4answers
700 views

What kinds of SSL certificates are usable for encryption?

I know that Verizon SSL certificates cost close to $600. There are couple of cheap alternatives, but I never really understood why Verizon does not offer such certificates. Look for RapidSSL at ...