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.

learn more… | top users | synonyms

13
votes
3answers
1k views

Multi-tenancy, SSL Certificates, and Subject Alternative Name

The X509 specification allows a CA to issue a single certificate for multiple hostnames, by using the "Subject Alternative Name" extension. From the spec: The subject alternative name ...
13
votes
3answers
223 views

Domain name expiration and TLS

If I purchase a domain name that has expired, do I have any assurance that the previous owner does not have a valid HTTPS certificate for the site? In other words, do CAs check domain name expiration ...
13
votes
2answers
18k 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 ...
13
votes
4answers
9k 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?
12
votes
3answers
555 views

Incorrect use of HTTPS?

When I open https://java.com my browser says “untrusted connection” but when I open https://www.java.com my browser says it’s ok. But it's the same site. So my question is: Is this a security bug? ...
12
votes
5answers
1k views

Why are certificates limited in time?

If a certificate has a limited duration of, say 5 years, but it gets somehow compromised after 2 years, waiting the 3 remaining years for it to get invalid is not a real solution to the breach ...
12
votes
2answers
3k views

Secure communication between applications using SSL Certificates

I am looking for a way how to secure communication between our applications. There is a "server" application listening on some TCP port and "client" application which is communicating with the ...
12
votes
5answers
2k views

Are self-signed certificates actually more secure than CA signed certificates now?

Are self-signed certificates actually more secure than CA signed certificates now? I ask this because recent leaks about the NSA spy programs and the secret FISA courts mean that the US government ...
11
votes
5answers
4k views

Does HTTPS Everywhere defend me against sslsniff-like attacks?

http://www.thoughtcrime.org/software/sslsniff/ If I have a domain on my HTTPS Everywhere list, so that theoretically it could be only visited via an HTTPS connection in my Firefox, then could an ...
11
votes
3answers
9k 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 ...
11
votes
3answers
2k views

Difference between Certificate Authorities

I've been wondering for a long time about is. There are many certificate authorities having different types of certificates. But even certificates of the same security level cost a lot more with one ...
11
votes
1answer
8k 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?
11
votes
1answer
354 views

Is using a CA more secure if I'm self-signing anyway?

We have a web application that we run for clients at their booth on fairs. The communication between clients and the server was done over HTTP until recently. We're currently working on improving ...
11
votes
1answer
2k 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 ...
11
votes
1answer
132 views

How CA ensures that a certificate request is coming from me?

To establish trusted SSL connection I need to create a certificate request. For example, if I use openSSL I can do it by the following command: openssl req -new -key privkey.pem -out cert.csr ...
11
votes
2answers
2k views

Is Apple's push notification service implementation vulnerable to a MitM attack

Recently(more info) I've spotted a strange message in the logs on my quite recent, fresh installation of OS X Mavericks 10.9.2 Apr 27 15:26:47 Ivans-MacBook-Pro.local apsd[194]: Unrecognized leaf ...
10
votes
5answers
1k views

Why is this certificate valid for so many domains?

If you look at the (invalid) certificate for https://i.imgur.com/ it says only valid for the following names: The certificate is only valid for the following names and then a list of about 100 names. ...
10
votes
3answers
2k views

How does an SSL server prove its identity?

This document says that a challenge response authentication proves the servers identity. But is a man in the middle attack still possible if the client does not verify domain name ? Please help me ...
10
votes
3answers
723 views

Can we make sure that the new Lavabit certificate is not under control of the FBI?

After the Lavabit shutdown, Ladar Levison (founder of Lavabit) announced that he’s "looking into setting up a site where users can download their data". Such a site is now online: ...
10
votes
4answers
1k views

Why isn't OCSP required by default in browsers?

According to the following screenshot, taken from firefox-3.6.17-1.fc14.i686, Firefox has an option to fail closed when unable to connect to OCSP servers. Can someone please explain why this isn't ...
10
votes
2answers
1k views

Are there really functioning quantum computers?

I saw this video on youtube on quantum computing. It says that a company called dwavesys has already made commercially available quantum computer. I checked on the website and it exists. I thought ...
10
votes
4answers
1k views

Can real end-to-end SSL encryption be made?

I've read the various questions tagged [ssl] and [mitm] and [proxy] and I couldn't find a duplicate. I've got a very precise question but first I need to give some background. Basically I'm very ...
10
votes
3answers
1k 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 ...
10
votes
5answers
2k views

Can Javascript/Flash verify the SSL connection to prevent “SSL Inspection”?

I'd like to determine if an SSL webpage is being debugged through Fiddler, or if it's going through an SSL Proxy. So some people may ask What is the point of re-validating SSL using javascript? ...
9
votes
2answers
236 views

Why do some certificates specifically identify a corporation and most don't?

Looking at a handful of websites that allow for/require HTTPS, I realized that the certificate for a few of them specifically identifies the owning corporation, but some (most) don't. What's the ...
9
votes
3answers
2k views

Can a wildcard SSL certificate be issued for a second level domain?

Something like *.com or *.net? How about *.edu.au? The RFC 2818 does not say anything about this topic.
9
votes
2answers
4k views

SSL Certificate revocation check

In the SSL protocol I don't see where the certificate is checked for revocation status. https://developer.mozilla.org/en/Introduction_to_SSL Is the Certificate Revocation and Status Checking not ...
9
votes
4answers
388 views

How to stop/detect someone else registering a certificate for my domain

With the proliferation of low-cost automated CAs what can be done to mitigate the attack of someone doing a spear phishing attack to get a login to our webmail system, then using an automated service ...
9
votes
1answer
339 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 ...
9
votes
7answers
267 views

Proving running code on a website is unchanged

Can it be proved to the user that the running code behind a website with security related code is the same as published? I'm currently looking at a few new project ideas and one involves secure ...
9
votes
2answers
4k 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 ...
9
votes
3answers
463 views

Are there any smartcard/hardware-tokens for certificate-based authentication which are easily destroyed?

It's all very well to use multi-factor authentication, but supposing you want to 'destroy a factor' so that in an situation where you are likely to be coerced to provide your passphrase, you can ...
9
votes
1answer
180 views

How should I store and secure self-signed certificates?

I'm fairly certain I shouldn't commit certificates into source control. Even if the repository is private and only authenticated coworkers (for example) have access to it. That would allow for ...
9
votes
2answers
399 views

PKI solution vendor selection

What would you look for in a (X.509-) PKI solution, and why would you look for that, given the following constraints: Available programming/sw-engineering know how is limited (ie, "OpenSSL with a ...
8
votes
2answers
8k views

Is there any way to get Chrome 27 to trust a self-signed cert? [closed]

I'm running latest gen Chrome (27) and preparing a demo that requires using a self-signed cert to support HTTPS on a local IIS website. The cert has been created with the correct common name for the ...
8
votes
5answers
1k views

I see two different sets of certificates for Google websites when I am at work and when I am at home

I see two different sets of certificates for Google websites when I am at work and when I am at home. I mean if I save the certificates (in firefox, click on the "Google.com" block on the left of ...
8
votes
4answers
1k 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?
8
votes
3answers
5k views

What SSL key should I make for IIS: RSA or DH? What bit length is appropriate?

I'm creating an SSL cert for my IIS server and need to know when I should choose the Microsoft RSA SChannel Cryptographic Provider or the Microsoft DH SChannel Cryptographic Provider. Question 1 Why ...
8
votes
2answers
533 views

How are browsers able to find and construct an alternate trusted chain path?

We had a web server that had the wrong SSL certs installed yet the browser was able to find another trusted path to a root and supply the page properly over HTTPS. We also have proprietary software ...
8
votes
3answers
676 views

Creating an X.509 certificate with an invalid signature

Creating an X.509 certificate with a valid signature with OpenSSL is pretty well documented all over the Internet. There are instructions on creating certificates that are signed by themselves and ...
8
votes
4answers
13k views

Recommendations for a Certificate Management tool for Linux [closed]

A client is looking to roll out OpenVPN to all its mobile employees and will use certificates on both the server and all clients. This creates a new challenge to manage all these certificates and ...
8
votes
2answers
1k views

Obtaining an S/MIME certificate without disclosing my private key to the TTP

I would like to obtain a trusted S/MIME certificate, but all the certificate authorities I have asked so far generate the keypair on their server, sign the certificate and send me both the private key ...
8
votes
1answer
2k 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, ...
8
votes
1answer
252 views

Why are website certificates secure?

I understand how HTTPS connections work, and I also understand they they require a certificate to know that the secure connection you have is with the right server (and not someone pretending to be ...
8
votes
4answers
1k views

Why is it a good idea that X.509 digital certificates have an expiry date?

What is the benefit of having certificates expire at some fixed date?
8
votes
2answers
326 views

Why is there no Domain CA?

I was asked to deliver a signed SSL certificate for an IIS server for a client. I have previously done this for the same client/domain before, so it start to seem like an unnecessary expense to hold ...
8
votes
2answers
447 views

How is an HTTPS login secure when pages use HTTP?

When someone go to eBay's website, they use an unencrypted connection between their PC and eBay's server. If they sign in, they are redirected to a secure site identified by its certificate and may ...
8
votes
3answers
687 views

Does the SSL encryption strength of a website really matter?

When looking to get an SSL certificate one is presented with a lot of options. For example lets take Network Solutions since they have a nice comparison chart. Immediately there seems to be 4 major ...
8
votes
2answers
576 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 ...
8
votes
1answer
230 views

distributing files to VPN partners

suppose i've created VPN certificates for a certain VPN-RoadWarrior-Client, expressed in the files VPN-RoadWarrior-Client.key and VPN-RoadWarrior-Client.crt*, however VPN-RoadWarrior-Client is ...