Certificate authorities verify the owner information of certificates by signing them.

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571 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 ...
9
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3answers
3k 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 ...
9
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1answer
262 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
975 views

How bad it is to install another company's root certificate to your server?

Our company uses a web server with a couple of web sites on it (private and public, over HTTP and HTTPS, some low risk and some high risk including online payments or other sensitive data for ...
8
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2answers
820 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 ...
8
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2answers
2k 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
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1answer
258 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
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1answer
559 views

How can a domain be impersonated with a fraudulent SSL certificate?

I was reading this article about the fraudulent certificates from Comodo back in 2011. It talks about domain impersonation. I understand that a fake website could be secured with the fraudulent ...
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5answers
2k 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 ...
8
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2answers
567 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/...). ...
8
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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 ...
8
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2answers
800 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 ...
8
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1answer
1k views

TLS 39 month certificate limit and Chrome's NET::ERR_CERT_VALIDITY_TOO_LONG error

Late last year the CA/Browser Forum decided to limit the maximum valid term of TLS/SSL certificates issued after 1 April 2015. After this time, as the official guidelines put it.. CAs SHALL NOT ...
8
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1answer
719 views

Force a subordinate CA cert to be signed to include a the CRL distribution point extension?

How can I attach a crlDistributionPoints parameter when signing a CSR I've generated as follows: openssl req -new -key /root/ca/private/private.key -out /root/public.csr I usually sign with: ...
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7answers
6k 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 ...
7
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7answers
4k 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 ...
7
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4answers
3k 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 ...
7
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2answers
590 views

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 ...
7
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2answers
3k views

How to detect the NSA MITM attack on SSL?

As Bruce Schneider reported here... https://www.schneier.com/blog/archives/2013/09/new_nsa_leak_sh.html ...the NSA reportedly performed a MITM attack on a company in brazil and decrypted their SSL ...
7
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2answers
467 views

How can we revoke all ssl certificates issued for our domain?

After having the hostmaster@domain.com email compromised, we found that someone issued a Domain Validated SSL certificate for our domain. Now we want to have all such certificates revoked. Is there ...
7
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1answer
216 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 ...
7
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2answers
6k views

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 ...
7
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3answers
256 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 ...
7
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3answers
1k views

Getting started with SmartCards; what equipment do I need, what do I need to know?

I have an unused SmartCard slot on my laptop and I want to learn how companies take advantage of it. Are all SmartCard slots capable of reading and writing a blank card? Are there compatibility ...
7
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1answer
4k views

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). ...
6
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3answers
780 views

What if someone steals a Certificate authority's private key? [duplicate]

What if someone could steal a Certificate authority's private key? I know this will (probably) never happen, but what would happen to the certificates that were already signed with this private key? ...
6
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4answers
3k 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 ...
6
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2answers
9k 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 ...
6
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5answers
343 views

Why are private certificates not trusted?

When we go to websites that have generated certificates themselves you see this red screen that says do not go there!: However when it is trusted by some companies it's all good. So I have a couple ...
6
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1answer
15k views

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

And know which are not default ones installed by Microsoft?
6
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1answer
4k 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.
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3answers
3k views

Why are Certificate Revocation List periodically renewed?

While studying a security course I have been asked this very question: Why are CRL periodically renewed, even if there are no new revoked certificates to add to the list? Honestly I can't find the ...
6
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4answers
2k 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 ...
6
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3answers
395 views

On-line cryptographically signed date/time?

I’m looking for a source of on-line cryptographically signed date/time. I do not need a full timestamp service, as I am happy with the information « date/time was that », without a link to a ...
6
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1answer
6k views

SSL Certificate framework 101: How does the browser actually verify the validity of a given server certificate? [duplicate]

Sorry I know this is a complete noob question and at the risk of posting a somewhat duplicate topic. I have a basic understanding of public/private key, hashing, digital signature... I have been ...
6
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2answers
4k views

How to use a Yubikey NEO (or any OpenPGP card or GnuPG in general) to sign X.509 CSRs?

Since the Yubikey NEO can be used as an OpenPGP card (see here) with three 2048 bit RSA keys, I thought about creating a CA from one of its public keys. Since the private key cannot be extracted ...
6
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2answers
934 views

Root SSL certificates and browser support

I have given three certs to be install on nginx AddTrustExternalCARoot.crt PositiveSSLCA2.crt www_example_com.crt So I concat them into a chained cert cat www_example_com.crt PositiveSSLCA2.crt ...
6
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1answer
6k views

What damage could be done if a malicious certificate had an identical “Subject Key Identifier”?

I'm looking at the the Subject Key Identifier attribute of a CA certificate and am trying to understand the role it plays in validation and infer how validating client software could get it wrong. ...
6
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2answers
2k 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 ...
6
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1answer
504 views

For a desktop application, why use an SSL certificate from a trusted authority?

When a web browser connects to a server and downloads an SSL certificate, a third-party trusted authority ensures that the client is talking to the host that it's looking for. If the host uses a ...
6
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2answers
575 views

Where are the anonymous/private domain validation SSL certs?

I have yet to find a CA that doesn't require personal information for DV certificates. Is this because all of the major browsers and operating systems have a policy to reject CAs that don't require ...
6
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1answer
682 views

Browsers silently adding trusted root certificates in Windows

When accessing https://internetbanking.caixa.gov.br (site of a well known bank in Brazil), the server returns a certificate signed by "Autoridade Certificadora Raiz Brasileira" (Brazilian Root ...
6
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1answer
239 views

Should I install my subordinate Certificate Authority on the domain controller? Why?

I must install a PKI in my organization. I work in a windows environment. I already set an offline CA. I must now install a subordinate CA. I have the choice between installing the subordinate CA on a ...
5
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3answers
307 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 ...
5
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6answers
1k views

Should the bit-strength selection of a child certificate be influenced by the CA or the chain?

All things being equal; suppose I have a CA chain that has 1024 bits of RSA encryption. Does this mean that my selection of a child CA or WebServer certificate gains no benefit from a higher level of ...
5
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4answers
3k views

Is it possible to create a self signed certificate authority?

Would it be possible to create a legitimate certificate with the CA bit set? I dont have a usecase associated with this, I'm merely curious. To explain my question : Suppose I sign a public ...
5
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3answers
5k 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 ...
5
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3answers
161 views

Guarding against rogue certificates

There has been a lot of news recently about certificates being falsely issued (due to the issuing authority having poor system security!). Apparently the targeted users were mostly Iranians, but it's ...
5
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3answers
4k 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: ...