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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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 ...
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1answer
518 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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4answers
563 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 ...
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7k 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 ...
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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 ...
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622 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 ...
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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 ...
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1k 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 ...
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2answers
909 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 ...
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4answers
540 views

What Country, State and City should I choose when requesting an SSL certificate?

I am really confused about the country, state and city I should select when submitting an SSL certificate. Should I provide the location of my servers or my current home address?I can always reissue a ...
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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 ...
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260 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 ...
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615 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 ...
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2answers
624 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/...). ...
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1answer
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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 ...
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1answer
288 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 ...
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2answers
912 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 ...
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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 ...
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751 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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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 ...
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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 ...
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1answer
8k 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 ...
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708 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 ...
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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 ...
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SSL root certificate optional?

I may have been under the wrong impression on how servers should be setup and what certificates actually get sent over during the server hello certificate message. I came across this today from ...
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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 ...
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473 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 ...
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218 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 ...
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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 ...
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3answers
264 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 ...
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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 ...
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2answers
3k 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 ...
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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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1answer
268 views

How does the OpenSSL Alternative chains certificate forgery (CVE-2015-1793) attack work?

The security advisory for the issue can be found here: https://www.openssl.org/news/secadv_20150709.txt OpenSSL Security Advisory [9 Jul 2015] Alternative chains certificate forgery ...
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3answers
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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? ...
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4answers
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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 ...
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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 ...
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5answers
355 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 ...
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2answers
5k views

What is an intermediate certificate authority?

What is meant by an "intermediate certificate authority?"
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3answers
520 views

Risk in buying an SSL cert from a not well-known party

Let's say I know a guy is selling an SSL cert at a very low price, assume they will generate a real and valid cert for me, since I need to submit my CSR to them and they pass to the CA, are there any ...
6
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1answer
18k 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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1answer
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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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2answers
249 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. ...
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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 ...
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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 ...
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3answers
407 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 ...
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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 ...
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2answers
977 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 ...
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1answer
799 views

Certification authority only for certain domains

Is it possible to make a certification authority certificate (even unsigned), which only allow to sign certificates for specific domain(s)?