A piece of data used in public key cryptography that contains identifying information (i.e. email address or web address), a hash of a public key, and a digital signature that authenticates the data in the certificate.

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1answer
4k views

SSL cert not turning green anymore

I'm running a drupal site and have asked about this issue pertaining specifically to the drupal aspect of it here. I know that the "Green" https url doesn't show up because the cert itself isn't ...
8
votes
2answers
12k views

Internal SSL Certificates?

As a developer I really like the idea of using OpenSSL to get perfectly good, free, SSL certs. Unfortunately, from all the research/analysis I've done so far, it doesn't look like there is any way to ...
10
votes
1answer
563 views

Why can the validity of an SSL certificate exceed the registration period of a domain?

I can understand why one might desire to purchase a certificate for multiple years but I am left wondering why it appears to be possible to obtain a valid certificate for a domain that may have come ...
7
votes
3answers
6k views

What does it mean for a digital certificate to be “signed”?

When someone says that a particular digital certificate (like an SSL cert) has been "signed with a key", what does that imply? Does that mean the certificate simply includes a key that should be used ...
1
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1answer
583 views

Purpose and Uses of Root SSL Certificates

I'm trying to wrap my head around the technical inner-workings of SSL and one of the last things I'm choking with is the concept of "root" SSL certificates (as opposed to "non-root"?!?). When and ...
-1
votes
2answers
592 views

Request/Creating a Code Signing Certificate

I have need for a code signing certificate which is trusted by a CA in the windows domain. How do I request/create this certificate? Do I have to request a code signing certificate on the ...
8
votes
4answers
1k views

Alternative to “web of trust”

Let's say I have an SMIME platform where I want to easily establish trust across the entire world for a particular purpose, for example for sharing valid financial information. I think that a ...
4
votes
2answers
273 views

TLS server key: possible to sign another TLS server key?

If I have a valid (verifiable) certificate C_K_s that links the server key K_s to "www.example.com", is it possible to : use K_s to sign K_d, and let S_K_d be this signature use K_d as the TLS ...
4
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2answers
185 views

In practice, does crypto software accept a *.com or or even a *. certificate?

Assuming this will be done with your own PKI, and not a public trusted CA. Considering that *.sub.domain.com is valid, and so is *.domain.com is valid, is it technically possible to issue *.com and ...
3
votes
2answers
208 views

SSL Certificate Signing by a CA

Per my understanding about SSL's, a user has to send his CSR to a CA (Verisign) to get it signed, and Verisign will send the sign X.509 certificate in return. What I don't understand is what, ...
25
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2answers
10k views

What are the advantages of EV Certificate?

What are the various advantages of using extended validation (EV) certificates than normal certificates which also provide comparatively high degree of encryption like RC4, 128 Bit? I know that the ...
5
votes
4answers
1k views

Clients trust my custom CA

I'm sorry if this is a dumb question. I'm new to all this. I have a large number of users. I need to be able to generate SSL certs for various internal domain names. All of these certs need to be ...
3
votes
2answers
542 views

Mitigations for Windows clients that don't support OCSP Nonces

Windows 7 clients (and older) don't support NONCES, a key feature used in securing the revocation check. Without a NONCE a MITM could replay a previously signed response and alter the validation of ...
3
votes
1answer
582 views

Is the Netscape SMIME extension still required in a certificate?

Every Windows 7 host has a Trusted Root certificate from Entrust that has the "Netscape Cert Type" extension (see image) I'm comparing inter-operable S/MIME extensions and see a pretty diverse set ...
8
votes
1answer
3k views

How does adding a random serial number improve a certificates' security?

This article says: "Finding collisions is a tricky process, since it requires you to muck with the bits of the public key embedded in the certificate (see this paper for more details). Also, ...
5
votes
1answer
18k 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
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2answers
365 views

Using digital signatures to identify users

Consider the following requirement: Bob should be able to verify that a payment request came from Alice. The above is in simple terms the basic idea, however, in reality Alice would be user A of ...
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3answers
1k views

Is it possible to use same certificate on several machines by exporting it?

My bank proposes certificate. They say I will be able to use it only on one computer. I don't understand: can't I use same certificate on several machines by exporting and reimporting it ?
1
vote
1answer
455 views

What makes a secure smartcard secure? Is contactless/RFID better?

In short what security features exist that I should look for in a smart card? What physical features exist, which are important? It appears smart cards may exhibit different levels of wear and ...
0
votes
1answer
707 views

How do I constrain Windows Smartcards for AD Authentication so that “anyExtendedKeyUsage” is not implied?

This document describes how there are 3 ways to constrain a SmartCard certificate The Enhanced Key Usage field defines one or more purposes for which the public key may be used. RFC 5280 states ...
29
votes
3answers
192k views

How do I clear cached credentials from my Windows Profile?

Windows seems to be saving my credentials for a variety of applications (terminal servers, etc) and I'd like to purge this data. How can I backup and purge this data?
2
votes
2answers
188 views

Using External Certificates on a network that doesn't permit outbound HTTP/S access

Some highly secure networks and DMZs prevent all communication to outside hosts. This can cause issues with validating externally signed data I can guess that issues with signature validation occur ...
2
votes
1answer
5k views

Clearing IE temp files don't erase CRL history. How can this be purged?

Even after I purge all my Internet temporary files, I still see information when I type certutil -urlcache How do I purge this information?
2
votes
3answers
2k 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 ...
3
votes
1answer
2k 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 ...
6
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1answer
3k 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 ...
1
vote
1answer
7k views

What are the OIDs (KU and EKU) necessary for Smart Card Authentication in Windows?

MSFT smart card authentication is listed in PKINIT RFC 4556 however I don't see any OIDs listed. Based on this and this KB article the EKU section of the certificate should contain "Client ...
18
votes
4answers
15k 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
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3answers
248 views

Whether certificates can be used for regulating access

I am thinking of a mechanism where I need to authenticate the client and control the access. I am thinking of using SSL for this purpose. I want to know whether using SSL solves my purpose. My ...
2
votes
2answers
496 views

Trust and signing: full public key or thumbprint?

Imagine a B2B service where two parties need to set up a two-way trust relationship: Alice will only accept requests from Bob, and Bob wants to know his requests are only going to Alice. When ...
1
vote
1answer
940 views

Best Practices for Storing Digital Certificate

I'm building an application where certain sensitive files need to be digitally signed before being stored in the file system using ASN.1 encoding, so they can be verified against a digital certificate ...
2
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2answers
2k views

How to use 'key material' so that multiple people can access protected files?

I'm not sure if this is the right SE to ask this question, but it seems more I have a database of files that needs to be encrypted such that multiple people with different passwords/logins to this ...
3
votes
1answer
142 views

Spurious SSL Certificates when accessing sites through enterprise network

I've noticed recently when I log on to sites like Hotmail that IE has been telling me there is something wrong with my SSL certs. When I examine the certs, the Issuer appears as "Blue Coat" from ...
3
votes
5answers
8k views

Two-factor authentication w/certificate and username & password?

Example scenario: ActiveSync Authentication method: certificate-based authentication AND Active Directory domain username-password Encrypted on device: public & private key AD username ...
12
votes
5answers
4k views

Is it safe to send a CSR via email?

I'm new to commercial SSL certificates and would like to know if a CSR that I generate is safe to send via email?
7
votes
3answers
8k views

How do I check that I have a direct SSL connection to a website?

I always thought that if I had an SSL connection there would be no MITM attacks. Now it appears that isn't true (see comments in this question Is it okay from a security perspective to read foreign ...
7
votes
1answer
225 views

Does dnssec protect against malicious registrars?

With the recent conspiracy theories around the registrar MarkMonitor Inc., the question arises, if DNSSEC protects against a registrar going malicious (or being attacked). This is especially ...
21
votes
2answers
33k views

Advantages of client certificates for client authentication?

I'm no security expert, so please just ask in a comment if I haven't made my question clear enough for an answer. The Scenario We have a server running WCF services, and a number of clients ...
19
votes
1answer
24k views

What is the actual value of a certificate fingerprint?

In a x509 digital certificate there is a "certificate fingerprint" section. It contains md5, sha1 and sha256. How are these obtained, and during the SSL connection, how are these values checked for?
7
votes
4answers
3k views

Does a CA need to have the same type of key as the certificates it is signing? RSA / Elliptic Curve (EC/ECDH/ECDSA)

I am making a CA that I hope to be able to sign RSA and Elliptic Curve-capable (EC) keys with. I was wondering if the best approach was: CA with RSA keys capable of signing RSA and EC CSRs CA with ...
1
vote
2answers
390 views

X509 mutual authentication: is there a security flaw?

On the client side, my application accepts the server's certificate in case of the client certificate being signed by this server cert. Is this correct or may it be dangerous? Is it better to ask a ...
7
votes
3answers
16k views

What does these warnings mean on an SSL connection by firefox (only)

I am connecting to a secure site and firefox mentions about identity: Owner: This website does not supply ownership information Verified by: Not specified Technical Details: Connection ...
0
votes
1answer
251 views

Authentication methods without trusting 3rd parties unless explicitly indicated

The plan is to have a situation in which no third parties have to be trusted unless you explicitly indicate so. For example CA's are only used when the contact explicitly added the CA as a trusted ...
0
votes
1answer
1k 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. ...
1
vote
1answer
125 views

Viable way to authenticate certificate without a web of trust?

For SSL certificates we have a web-of-trust principle. If we are allowed to make alterations to the certificate format, are there viable ways to automatically or semi-automatically authenticate the ...
7
votes
7answers
9k views

What is the danger of hosting your SSL certificate yourself?

I have Active Directory Certificate Services on my server, which makes it possible for me to deliver an SSL certificate for the websites hosted on the same server. I know that normally, I need to ...
3
votes
1answer
1k views

exponent value in certificates

I have seen that in gmail, there are 3 certificates in hierarchy. I noticed that all the certificates have the same exponent(65537 with 24bits). Why is the exponent value same for all certificates and ...
71
votes
4answers
27k views

Are all SSL Certificates equal?

After running a few tests from Qualsys' SSL Labs tool, I saw that there were quite significant rating differences between a GoDaddy and VeriSign certificate that I have tested against. Are all SSL ...
2
votes
1answer
1k views

How to generate self-signed certificate for S/MIME with usage 'signing' only, like DOD uses

I'm testing a feature to support S/MIME mail signing and encryption. As far as I know US DOD has quite strict standard on these certificates. So that DoD uses separate authentication, signing, and ...
6
votes
2answers
2k views

Is DIGEST-MD5 secure if done over HTTPS?

If the DIGEST-MD5 negotiation is done over an HTTPS connection instead of HTTP, does that prevent this list of disadvantages from Wikipedia?: Digest access authentication is intended as a security ...