A Certificate Authority is the collection of hardware, software, and people responsible for issuing certificates in a hierarchical PKI. CAs may be public, as in SSL / TLS and government IDs, or private, as in corporate infrastructures. The primary responsibility of a public CA is to verify the ...

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How secure is “Let's Encrypt”? [duplicate]

I just configured and installed a free SSL certificate from Let's Encrypt. It's great, and very easy to set up. However in this post-Snowden era, I was wondering how secure this really is. For ...
14
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1answer
461 views

Yubikey / GPG with OpenSSH signed key

I am currently looking into the possibility of using Yubikey (NEO)'s to store the private SSH keys of my users. By searching the internet I've found several places that explain how you can generate a ...
13
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3answers
1k views

Should I be concerned that Google no longer trusts specific Symantec root CA cert that is also on my Windows system?

This is related to this other question which refers to Google moving to distrust the "Class 3 Public Primary CA" root certificate operated by Symantec Corporation, across Chrome, Android, and Google ...
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3answers
9k views

Why is my Positive SSL certificate deemed insecure by Google Chrome? [duplicate]

We run a website over HTTPS with a wildcard certificate from Positive SSL. Today, when I opened Google Chrome (v. 42.0.2311.90 m) and navigated to the site, I noticed a red cross through the https ...
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4answers
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How do certificate issuers become trusted?

From what I understand, the certificate scheme that TLS/SSL relies on works because your computer has trust for major CA issuers built into it. That is, your OS is installed with certificates for ...
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2answers
4k views

How does DNSSec work? Are there known limitations or issues?

Based on information from this site, DNSSec is needed to protect us from a number of DNS and SSL / TLS hacks, including: DNS spoofing, especially on wifi or shared medium Registrars that abuse their ...
13
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1answer
3k 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 ...
12
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6answers
3k views

Is it possible for corporation to intercept and decrypt SSL/TLS traffic? [duplicate]

I found there are some companies claim that they offer service that can eliminate SSL/TLS blind spot, such as Blue Coat and Gigamon. Are they talking about some way of decipher the https content (...
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4answers
3k 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 ...
12
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1answer
752 views

Why isn't there a certificate revocation request standard?

Say I am building a Certificate Authority software and I want to automate certificate revocation as much as possible. I know it will not be possible in some cases, like if the building where the ...
12
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4answers
5k views

What are the risks of a localhost signed cerificate?

In our company we have an internal CA certificate for signing various things including the proxied (MITM'd) HTTPS connections. Suppose we use this CA to sign a key for "localhost" for use in ...
12
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4answers
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Do I really need all these Certificate Authorities in my browser or in my keychain?

There are lots of strange looking Certificate Authorities in my keychain as well as Firefox. I am sure they are legitimate CAs (as they are the same on my Mac and PC and other computers I checked). ...
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4answers
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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 ...
11
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2answers
863 views

How long can X.509 certificate chains be?

Usually, I only see certificate chains with a root CA, an intermediate one, and a third one for the particular SSL/TLS website; but can X.509 certificate chains be deeper than 3 levels? Is there a ...
11
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2answers
805 views

Is using HTTP for OCSP a potential vulnerability? [duplicate]

While inspecting my CA-approved cert, I noticed the following oddities: Extensions/CRL Distribution Points: Not Critical URI: http://crl2.alphassl.com/gs/gsalphasha2g2.crl Extensions/Authority ...
11
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3answers
35k views

How can you check the installed Certificate Authority in windows 7/8?

And know which are not default ones installed by Microsoft?
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5answers
9k 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 ...
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2answers
2k views

Is StartSSL.com a trustworthy site? [closed]

I just got the following email: Dear StartCom customers, This electronic mail message was created by StartCom's Administration Personnel: StartCom, a leading global Certificate ...
11
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1answer
530 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
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1answer
175 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
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2answers
2k 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 ...
11
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3answers
203 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 ...
10
votes
4answers
783 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 ...
10
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1answer
575 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 ...
10
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1answer
7k views

Getting a Root CA accepted in systems and browsers

I would like to ask about the procedures for a given CA to get one of its root CAs (SSL issuance CA) to get accepted and installed as a trusted root CA in operating systems and browsers.
10
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1answer
919 views

Should I use a Certificate Revocation List?

I've been trying to provide security to my API. I will issue certificates to my clients to access my API through a TLS channel. So it'll be a SSL-Client Authentication. I'm wondering, should I use ...
10
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2answers
1k views

Certification authority limited only to certain domains

Is it possible to create a CA certificate (even unsigned), which is only allowed to sign certificates for specific limited domain(s), so that it can't be misused for other domains?
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2answers
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How is an X509 certificate signer verified?

Lets say I create a self-signed X509 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 ...
10
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2answers
5k views

Are certificate authorities required to obey to the signature algorithm (hashing) specified in the CSR?

I was playing a little bit with signature algorithms, trying to determine which CAs among the ones I use are currently issuing SHA2 certificates. I generated a CSR specifying the SHA256 hash (either ...
10
votes
1answer
487 views

Where does a Hyper-V guest get its entropy when generating a certificate authority key pair?

According to findings by the EFF's SSL observatory, there are "tens of thousands of keys that offer effectively no security due to weak random number generation algorithm." My understanding of that ...
9
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8answers
6k 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 ...
9
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2answers
1k views

How are digital certificates compared?

I have read about SSL and TLS; I know how RSA works and why digital certificates are necessary (more or less), but I am curious about how we prevent a fake digital certificate. The operating system ...
9
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1answer
15k views

SSL certificate chain verification

After reading many articles and watching many tutorials I decided to be specific because there are some things about SSL certificate chain verification and SSL cetificate verification in general that ...
9
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3answers
8k views

How trustable are third party root certificates?

I recently tried to use Fiddler2 from a third-party vendor Telerik. While decrypting the HTTPS traffic of my network, it asked me to install its own root certificate in my Windows operating system: ...
9
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4answers
696 views

How does “Let's Encrypt” provide authenticity?

https://en.wikipedia.org/wiki/Let's_Encrypt https://en.wikipedia.org/wiki/Information_security#Authenticity AFAIK with "Let's Encrypt", we could create HTTPS websites with only one command. ...
9
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 ...
9
votes
2answers
1k 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 ...
9
votes
1answer
705 views

What are the problems with creating an own CA for intranet?

In the comments to Creating my own CA for an intranet several people strongly advise against creating your own CA for an intranet. Especially: don't do it. Nope. Bad idea. Buy $10 CA signed ...
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2answers
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When you buy a certificate, does the certificate authority have (a copy of) the private key?

I always assumed that the process for getting a (trusted, not self-signed) certificate was more or less like this: You generate a public and private key pair From this key pair you generate a ...
9
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5answers
3k views

Understanding SSL certificate signing

I am trying to understand how SSL certificate and signing and the chain of trust works. I know about root CAs and that they are used to sign intermediate CAs that sign the end certificates that are ...
9
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2answers
3k 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 ...
9
votes
2answers
828 views

What kind of certificate do I need to be able to sign my own subdomain certificates?

We are making a web-based application that will be installed in intranets as a virtual machine image (we send the user a CD with the virtual machine image, user runs it in a VMWare/VirtualBox/...). ...
9
votes
2answers
2k views

What happens when certificates further up the chain expires before mine? (Equifax/GeoTrust)

I just bought a certificate from RapidSSL. Looking up the chain, I found GeoTrust who is signed by Equifax. Then I realized that the ”Equifax Secure Certificate Authority” is due to expire on 2018-08-...
9
votes
2answers
428 views

I want trusted SMIME certificates for 3rd parties. Is this a reasonable configuration?

I want to send out SMIME certificates with my emails, and want to deploy the following PKI Root01 (All EKU, All Constrants, No Restrictions) PolicyInt01 (Internal applications, not trusted by 3rd ...
8
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3answers
2k 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 ...
8
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4answers
5k 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 ...
8
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4answers
2k views

Why are there very expensive and cheap SSL same type certificates? [duplicate]

I am about to launch an online shopping site (currently running http) and I was thinking heavily of moving to SSL which includes a green bar, because this is very important. However, when I first ...
8
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4answers
4k 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 ...
8
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2answers
600 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, ...
8
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3answers
4k 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 ...