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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6
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2answers
274 views

Custom data in SSL certificate

I am looking for a way to add extra, custom data in a SSL server certificate issued by a standard CA. Is this possible? I want to get a SSL server certificate issued by a standard CA, so that it'll ...
1
vote
0answers
26 views

Problem using custom CryptoNG KSP on IE 11

We are currently developing a custom KSP (Key Storage Provider) for a Key Storage System. We successfully developed a CSP (CryptoAPI) and a KSP (CryptoNG) provider, and both work really fine for ...
5
votes
1answer
140 views

Is there an official standard and/or name for PEM certificate bundles?

This is a question that's not really about security proper. It's about security/crypto nomenclature. It's been bugging me a bit, so here goes: I know two approaches for bundling related ...
5
votes
1answer
42 views

Can attribute certificates be used with TLS / HTTPS?

Can attribute certificates (also known as authorization certificates) be used with HTTPS? For instance, can a HTTPS server supply an attribute certificate in addition to its ordinary SSL certificate? ...
104
votes
13answers
27k views

Is there any technical security reason not to buy the cheapest SSL certificate you can find?

While shopping for a basic SSL cert for my blog, I found that many of the more well-known Certificate Authorities have an entry-level certificate (with less stringent validation of the purchaser's ...
3
votes
1answer
56 views

Best practice to verify data against a CA

Let's say that I have signed my public key with a trusted CA and the CA provided my with a signed certificate, and I want any client applications to verify against this certificate. The general ...
1
vote
2answers
212 views

What if the Local Windows Cert Store is Compromised?

The diagram below illustrates chaining digital certificates up to a publicly trusted Root Certificate: I have been researching how trusted root authorities (such as GlobalSign or Verisign) are used ...
3
votes
0answers
262 views

Untrusted connection when logging to stack exchange sites

I was able to log into various stack exchange sites with no problem, but as of today 1/5/2016 I'm getting the following error message with firefox 43.0.2: You have asked Firefox to connect ...
5
votes
1answer
114 views

Securely build a list of trusted CAs

Some distributions of the cURL bundle include a utility mk-ca-bundle.pl which compiles a ca-bundle.crt from Mozilla's root certificate store for use as a list of trusted authorities. The script prints ...
9
votes
1answer
511 views

Why does GoDaddy have four different certificate chain, G2, G3, G4?

I see from Godaddy they have multiple certificate chains https://certs.godaddy.com/repository GoDaddy Certificate Chain GoDaddy Certificate Chain - G2 GoDaddy Certificate Chain - G3 GoDaddy ...
1
vote
1answer
231 views

Identify the attestation certificate (X.509) in Fido U2F registration response

I'm trying to identify the attestation certificate (X.509) in Fido U2F registration response as described in fido-u2f-raw-message-formats-v1.0-rd-20141008.pdf document: An attestation certificate ...
8
votes
1answer
404 views

How to use encryption on a site that only uses an IP address, no domain name?

You can use SSL/TLS certificates and etc. on sites with domain names, but I don't know if it's possible to use them for IP addresses. If this is the case, would I have to use a self-signed cert and ...
4
votes
1answer
59 views

Protect sensitive information in a password-free, shared database

I'm working on a webserver that stores resources in Redis. To make swarm-deployments as hassle-free as possible, I'm implementing an option where the server doesn't need to access the filesystem to ...
0
votes
2answers
246 views

Security of SSL certificates bought via resellers

There are many SSL certificate resellers - some are well known enterprises with good reputation (e.g. domain name registrars) while others are small and unknown companies. It is clear that resellers ...
3
votes
1answer
87 views

Why do some EV certificates show the full address of the organization, but others only show the state or city?

If I go to www.comodo.com, I can see their registered office address in the EV certificate: CN = www.comodo.com OU = COMODO EV SGC SSL OU = COMODO EV SSL O = Comodo Group Inc. STREET = 1255 Broad St. ...
1
vote
2answers
133 views

Why/when would a CA make a generated public key available to the public at large?

I'm confused about this section in my CEH security exam training material: A CA is able to perform a number of roles in addition to the validation process outlined here. Some actions that a CA is ...
5
votes
2answers
123 views

Why do so many browsers show sites with revoked certificates?

Everyone seems to agree that it is REALLY important to protect private keys so the encrypted Internet can remain just that (see for example at How do certification authorities store their private root ...
11
votes
3answers
196 views

Why is Firefox shipped with expired root certificates?

What's the purpose of shipping Firefox with expired root certs? I checked and there are two expired certs listed. In fact the company's website for the first expired cert (A-Trust) states that the ...
2
votes
1answer
93 views

How does Windows certificate manager verify a file's certificate, if the root certificate is not in the store?

I'm working on a project which requires certificate verification for executable files. I have created my own trusted root certificate store, and used openssl to perform verification. However, when I ...
2
votes
2answers
60 views

Why not to use the same subordinate issuer CA for generating certificates that will be used for different things?

Microsoft has recommended my organization to use different subordinate issuer CAs in order to issue certificates that will be used for different things. For example, they recommend to use a CA for ...
0
votes
0answers
25 views

Is there any extra validation that Firefox perform to certificates serial number

I open a secured site in my computer. for my reasons, I created new certificate every 15 minutes. I noticed that, sometimes, Firefox "doesn't like" my certificate. after little investigation, I ...
38
votes
3answers
97k views

Understanding 2048 bit SSL and 256 bit encryption

On DigiCert's page, they advertise a 2048 bit SSL with a 256 bit encryption: http://www.digicert.com/256-bit-ssl-certificates.htm What exactly is the difference here and why are two encryption bits ...
6
votes
3answers
250 views

Why should my certificate signing request be signed by my private key?

Why should my certificate signing request be signed by my private key? Even if I obtain a bogus certificate out of someone else's public key, that is going to be useless, since in SSL the ...
6
votes
4answers
5k views

Man-in-the-middle Blue Coat proxy SSL or what?

I have just discovered that my workplace has enabled some new features in the Blue Coat network proxy. It seems like all HTTPS certificates in Chrome on Windows are being issued by this internal ...
1
vote
2answers
65 views

Use DANE to authentify mail sender

I have my own virtual DNS infrastructure, from the root to the mail server mail.example.com. Everything is signed using DNSSEC. client1@example.com can send email to client2@example.com, digitally ...
2
votes
2answers
388 views

Choosing the right X.509 certificate infrastructure for securing LAN communications between a PC and a device

Edit: seems like I was quite hasty when typing in my question at first, so here is an updated version of it. I am developing an application that runs on PCs which are on the same LAN as other ...
5
votes
2answers
119 views

Understanding Digital Certification as as a whole starting from a normal http request

I am trying to understand the difference between digital signature and digital certification and how they work as a whole together on a high level perspective. I hope gurus here can point to me if my ...
4
votes
1answer
970 views

How can a trusted intranet certificate be issued if they are being phased out?

I've just seen this article regarding the phasing out of intranet names on SSL certificates. However, CAs such as this one claim to still issue them and it will be "Trusted by all popular browsers" ...
2
votes
2answers
665 views

Wildcard SSL Certificates & SAAS

From what I have read, using a wildcard SSL/TLS certificate is not advisable, how do you do certificate issuing & management in your SAAS application(linux) where each client has a user selected ...
3
votes
1answer
472 views

ECDSA/RSA certificates and cipher selection

In this image can someone tell me if a standard RSA certificate can support the EC*_RSA ciphers listed? If so do you create the typical RSA keys when you are creating the CSR? Also I am fairly ...
3
votes
1answer
226 views

Getting a certificate warning for one email but not another

When I log into outlook.com using Chrome browser, I get a certificate warning for one account but not another. One says my connection is private, the other says it "may not be private". Here are the ...
3
votes
0answers
47 views

Certificate and Path validation for S/MIME

I am working on a S/MIME client development and was wondering if there is a list of certificate and path validation checks that a client needs to perform while validating an email signature. My ...
5
votes
2answers
137 views

How do I produce a CA signed public key?

I have a need to have somebody else encrypt secret data with my public key that I can then decrypt with my private key. I have produced an RSA private/public key pair with OpenSSL gave them the public ...
2
votes
1answer
193 views

Managing/Deploying a code signature certificate - Java Applet

I wonder how to manage/deploy a code signature certificate used by the JVM in a corporate context. Suppose you signed a Java applet (executed in browser by corporate users), how do you deal with the ...
1
vote
2answers
64 views

Do secure ciphers break multi-domain certificates?

In the past days, I was halfway successful with securing my websites. So far, I have achieved the following: Get a certificate from letsencrypt.org, securing the domains example1.com, example2.com ...
1
vote
2answers
83 views

Application that uses USB token to assign user on a server

I have the following situation: One user with a USB token certificate access a site and log-in using this certificate, the logging process ask for the USB token password; When the user is logged he ...
1
vote
2answers
109 views

What server software uses .der?

So apps linked against openssl uses PEM, and Windows generally uses PKCS12, but I haven't seem much .DER in the wild - what server software uses DER?
38
votes
2answers
29k views

What is the difference between serial number and thumbprint?

I have problems to understand what is the difference between the serial number of a certificate and its SHA1 hash. The MSDN says: Serial number A number that uniquely identifies the ...
1
vote
0answers
27 views

Can there be two certificates with a same serial number in the world? [duplicate]

Recently I came across this odd question. I hope, Serial number is unique across certificates signed by a particular CA. So is there any chance that two different CAs sign two different certificates ...
0
votes
1answer
72 views

Why does not appear the public key from certificate?

I'm creating a certificate in LAMP, the public key is: Public Key: 30 81 89 02 81 81 00 CC CB 64 54 C2 FA A3 7A 81 36 5F 1B D5 10 81 75 B7 42 02 31 83 B1 D5 5A 76 72 6A 77 BE 62 69 16 AB EB 39 66 B5 ...
8
votes
2answers
592 views

How do user receive server's certificate?

Let's imagine our user's computer wants to talk to some server for the first time in history via https. The computer sends a hello message, the server sends his public key and the certificate, ...
3
votes
2answers
112 views

Using Self sign certificate in internet

Basically the purpose of SSL cert is for trusting each other. If I have an application that only a few clients I know can use, is generating self sign certs enough? Or do I really need to sign with a ...
0
votes
4answers
718 views

Do all non-CA certs have to be End Entity certs?

Still learning the differences between certs. Can someone explain? The internet has so far been surprising not lucid in describing certificates. *EDIT to clarify EE
-1
votes
2answers
136 views

Client certificate vs HMAC

My team is working on web API project for one customer which will call this API. Now we are thinking about authentication. We've stopped on two options HMAC and client certificates HMAC: pros - no ...
3
votes
1answer
98 views

TLS - How to know a CRL URL is not changed

If a hacker would manage to sign a certificate with a stolen (private) key of a CA and would remove or change the URL in the CRL Distribution Points extension, and later the certificate would be ...
1
vote
2answers
98 views

Verification of client certificates

I've read a lot of articles about client certificates. Please correct me if I'm wrong: client certificates are issued using CA CA could be created by myself (self-signed) or bought client ...
0
votes
2answers
59 views

Analyzing whether browser certificates have been compromised

How can I know that my installed certificates (in Firefox), are (still) reliable?
10
votes
2answers
7k views

How to set “Not Before” value to past when creating certificate request

We have lots of embedded TLS clients on the field. TLS Servers must be authenticated. Because long power cuts may reset clock of those devices, we have requirement to use certificates with validity ...
2
votes
2answers
158 views

Is there any mechanism to audit which signed certificates are unrevoked?

We are currently using EasyRSA and OpenSSL to manage our user VPN certificates for OpenVPN. The process we have in place currently is: User generates a CSR on their laptop and sends it to us to sign ...
0
votes
2answers
137 views

Why can you not trust a certificate directly?

If you want to set up a service that is signed using some Certificate Authority system (SSL/TLS, certain configurations of IKE, etc), if you want to use a self-signed certificate (e.g., for testing), ...