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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15
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7answers
8k views

How do I check if a gmail/gtalk SSL certificate is valid?

Pidgin started prompting me to accept/reject new gtalk SSL certificate a few days ago and I am not able at the moment to tunnel the traffic to check if it would continue to happen or if it wouldn't ...
8
votes
2answers
334 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 ...
21
votes
2answers
2k views

Digital Certificate deployment: using two certs for each user?

At a large enterprise environment I have come across a deployment approach for Digital Certificates where each user is issued two (2) key pairs: One for signing documents, emails, etc. that is ...
16
votes
3answers
25k 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?
4
votes
3answers
283 views

Are SSL certificates from a CA necessary for secure communication?

Am I right in thinking that SSL certificates from a CA are purely for identification purposes and serve no purpose in the actual encryption of data? In other words if I were to create a self signed ...
18
votes
3answers
8k views

What vulnerabilities could be caused by a wildcard SSL cert?

In a comment on this answer, AviD says: "There are numerous security issues with wildcard SSL certs." So, what are the problems? I understand that the same private key is being used in multiple ...
6
votes
3answers
1k views

How and when should I use OpenSSL for IT Security? How do I understand the output?

I'm discovering OpenSSL, and already used it to diagnose a faulty SMTP TLS connection, but I'd like to get a better / full understanding of the tool and how to use it. What resources should I use ...
40
votes
5answers
25k views

Does https prevent man in the middle attacks by proxy server?

There is a desktop client A connecting to website W in a https connection A --> W Somehow between A and W, there is a proxy G. A --> G --> W In this case, will G be able to get the ...
22
votes
3answers
10k views

What are the risks of self signing a certificate for SSL

Let's say I sign a SSL certificate for myself, and I'm not using a certified CA. What are the risks and/or threats of doing it?
14
votes
4answers
15k 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 ...
7
votes
3answers
226 views

Limiting the root certificate chain

I'm playing around with the idea of running a mini-CA with my (hobby) website, likely only used internally with a few select developers for internal emails, client authentication, staging/development ...
4
votes
2answers
663 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 ...
2
votes
2answers
132 views

How can I force certain the webclient to honor or remember certain parameters from the webserver?

HTTPS is subject to several MITM attacks, that is clear. However I think it would be helpful to the ITSec crowd if there was a way to force a certain browser behaviour when accessing known-trusted ...
4
votes
1answer
673 views

What is the impact of certificate validation level (or class) on deployed web applications?

Certificates can have a class level (or validation level). What is the impact of these levels on deployed web applications? More specifically: Is the certificate level included in the certificate ...
3
votes
2answers
542 views

Inspecting a TLS Certificate to determine RSA Key Usage restrictions

With regard to this answer, I have a question about Key Usage in an SSL certificate. Most SSL server certificates have a RSA key which is not restricted through a Key Usage extension, so you can ...
4
votes
1answer
285 views

How secure is a https website? [duplicate]

Possible Duplicate: Does an established ssl connection mean a line is really secure When I visit a website -- say, https://ebanking.pick-your-bank.com -- my browser (fully patched version ...
1
vote
3answers
781 views

Benefits to using EV certificates with a privately hosted Certificate Authority

For companies that have implemented their own internal CA, is there any benefit to configuring that CA to issue an EV certificate? Do any SSL Proxies (like Bluecoat) mimic the EV certificate of the ...
24
votes
5answers
18k views

What ciphers should I use in my web server after I configure my SSL certificate?

There are many great questions that ask what is the best certificate to use for a website; but once the certificate is purchased, there is also the possibility to choose or edit the Cipher list. ...
14
votes
4answers
1k views

Is my Company Tracking Me?

Every time I try to connect to a site through HTTPS from my office computer, there is a Certificate Error thrown 2-3 times before showing the login screen. Till now I use to ignore this and click ...
9
votes
4answers
15k 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 ...
3
votes
2answers
146 views

Need an overview of web service / web site security world, where do I start? [duplicate]

Possible Duplicate: Resources to learn about security I'd like to get a good understanding of modern issues in web security and get insight into what it takes to keep your sites and ...
6
votes
3answers
399 views

Why are CA's signing keys available on the internet

I am not very knowledgeable about CA certificates, but I thought these things mainly said "The public key for bank X is Y, and this is verified by CA Z". Once you've bought this certificate, there is ...
11
votes
4answers
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 ...
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 ...
10
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.
4
votes
3answers
654 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 ...
15
votes
3answers
1k views

What are the risks of a Certificate Authority hack for 'the average user'?

Recently the DigiNotar CA was hacked, and rogue certificates were issued. Since they also issue certificates on behalf of the Dutch government, the government made a statement about it as well, ...
3
votes
4answers
3k views

I had SSL certificate on my site but still it has been hacked…how to prevent this from happening?

I used SSL certificate on my site but still it has been hacked. How do I prevent this from happening? Do SSL certificate come with a waranty which would compensate me because my site was hacked?
26
votes
3answers
2k views

What is an SSL certificate intended to prove, and how does it do it?

If I get an SSL certificate from a well-known provider, what does that prove about my site and how? Here's what I know: Assume Alice and Bob both have public and private keys If Alice encrypts ...
6
votes
2answers
283 views

How protective should we be of an SSL client certificate?

We've got an application where the database connection requires an SSL client certificate. How protective do we need to be of this certificate? What are the implications if someone else gets it? I ...
4
votes
3answers
740 views

Web Certificate invalidation - You might be connecting to a website that is pretending to be [Site name]

Recently while trying to log-in to Facebook this notification starts to appear: At first I ignored it (by pressing Continue), but it started to popup every time I navigate through the website! I ...
8
votes
3answers
714 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 ...
3
votes
1answer
661 views

What kind of certificate do I need to be able to make and sign my own digital signing certicates?

At build time for a program, I would like to generate a new key pair, and create a certificate that will be embedded (securely) into the program. The purpose of the key pair is to digitally sign an ...
2
votes
3answers
3k views

SSL verification of host name of https server

I recently found that a library I am using (specifically Apache HTTPClient) when is configured to verify the hostname of the remote server against the certificate's CN it just seems to be doing a ...
2
votes
1answer
2k views

Securing WCF service with X.509 cert [duplicate]

Possible Duplicate: What is the difference between an x.509 “client certificate” and a normal SSL certificate? I'm getting really confused with WCF and certs. I have a WCF ...
16
votes
3answers
2k 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 ...
1
vote
1answer
117 views

Challenge Response across several hops

This is a follow-up question to "When should I use Message layer encryption vs transport layer encryption". I need to send a certificate from the mobile phone to the server. Regardless of all the ...
3
votes
3answers
149 views

Warn about specific CA in Firefox

Consider a setup where all HTTP/HTTPS traffic goes through a proxy. The certificate of this proxy must be trusted by all browsers (in this case, Firefox). This certificate replaces the original ...
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 ...
11
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 ...
21
votes
4answers
82k views

How can I export my private key from a Java Keytool keystore?

I would like to export my private key from a Java Keytool keystore, so I can use it with openssl. How can I do that?
6
votes
2answers
3k views

Getting self-signed SSL certificates for all https connections made from some premises

Context: I'm currently working as an expat for my company in a country where the Internet is notably untrustworthy. It made the headlines a few months ago for stealing facebook, twitter and gmail ...
6
votes
1answer
922 views

How do I learn Cryptographic/Mathematical notation

I asked a question earlier where it was recommended that I describe my issue using standard cryptography notation. How do I learn this notation and how to convey my approach? How can I annotate this ...
8
votes
1answer
242 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 ...
12
votes
3answers
561 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? ...
7
votes
2answers
677 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 ...
56
votes
7answers
40k views

Certificate based authentication vs Username and Password authentication

What are the advantages and drawbacks of the certificate based authentication over username and password authentication? I know some, but I would appreciate a structured and detailed answer. UPDATE ...
15
votes
1answer
3k views

REST specific security weaknesses

I need to start working with RESTfull Web Services. SOAP based web services have already so many standards to secure communication, establish trust etc. I am not aware of any for REST. What I would ...
8
votes
1answer
1k 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 ...
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 ...