Questions tagged [certificates]

A piece of data used in public key cryptography (specifically public key infrastructures) 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. For questions specifically about [x509], [certificate-authority], or [public-key-infrastructure], please use those tags.

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12
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2answers
4k 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 ...
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Is there greater risk to browsing websites with invalid certificates than websites with no certificate at all?

The information security community is generally very adamant that users should not proceed to visit websites that have invalid SSL certificates. Web browsers have gotten less and less cooperative with ...
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3answers
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How will SHA1 deprecation affect internal CA's?

I am hearing that the SHA1 Deprecation notices from MS/CHROME only apply to certs that are a part of a public trusted root program. This makes one believe that IE will have new logic built in to allow ...
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Can we always remove WWW from a host name? [closed]

When I'm opening https://india.gov.in, it's opening all right. But for https://www.india.gov.in, the browser is throwing a certificate error. Why is that happening?
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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: ...
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SSL Certificate revocation check

In the SSL protocol I don't see where the certificate is checked for revocation status. https://developer.mozilla.org/en/Introduction_to_SSL Is the Certificate Revocation and Status Checking not ...
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3answers
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How does obtaining a SSL certificate work?

I have been carrying out some work on SSL certificates and found that there are some places that charge you for an SSL certificate, but, how do they obtain the rights to do so? And, how, are they ...
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4answers
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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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2answers
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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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Validating an SSL certificate chain according to RFC 5280: Am I understanding this correctly?

we're in the process of replacing certificates with SHA1 hash due to Google's move to let them appear less secure in Chrome. The replacement certificates use a different intermediate CA than the ones ...
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What part of TLS specifies how to verify a certificate chain

I have sometimes run into a situation where I see a root CA certificate which is set to expire sooner than the intermediate CA certificate. My question is - if you were interested in keeping your ...
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2answers
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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. ...
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Why do Chrome and Firefox report a different server certificate and issuer than OpenSSL?

When I visit https://somesite.org using Chrome or Firefox and inspect the server certificate, everything looks OK to me. I see SSL Server Certificate, CN, O, OU that appears to match somesite.org ...
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1answer
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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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3answers
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Creating an X.509 certificate with an invalid signature

Creating an X.509 certificate with a valid signature with OpenSSL is pretty well documented all over the Internet. There are instructions on creating certificates that are signed by themselves and ...
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5answers
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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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3answers
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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 (...
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1answer
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What is a Certification Path in SSL certificate?

I've been trying to learn more about Digital certificates for the past few days and I'm struggling in order to understand how actually this concept is applied in the real world. Anyways, as I visited ...
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1answer
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Why is one of three browsers (Chromium) reporting an invalid HTTPS certificate?

A few days ago, Chromium started to report Flickr's certificate as problematic: The server presented a certificate that was not publicly disclosed using the Certificate Transparency policy. This is ...
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1answer
616 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 ...
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1answer
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How to use OpenSSL generated keys in Java?

I have my pair of Public and Private keys and my certificate. Those where created in OpenSSL (why? because I was asked to do it in OpenSSL). Now I want to use those things to make a Java app that ...
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1answer
220 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 Anyone ...
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3answers
514 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 ...
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1answer
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How should I store and secure self-signed certificates?

I'm fairly certain I shouldn't commit certificates into source control. Even if the repository is private and only authenticated coworkers (for example) have access to it. That would allow for ...
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3answers
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Why are SSL certificates valid only from a certain date?

Each SSL certificate is valid starting from a specific date and up to the expiration date. What's the point in that "valid from" date? Why do we want a certificate to only be valid after a specific ...
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1answer
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Are X.509 nameConstraints on certificates supported on OS X?

I have the following "chain" of certificates on a test machine right now: A self-signed CA cert, in my Keychain and trusted & trusted by Firefox. A CA cert with with the following, X509v3 Name ...
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2answers
635 views

What real life scenarios require separate end user certificates for Signing and Identity?

Based on this question, I'm interested in any rational argument that would support the idea of maintaining separate signing and authentication certificates. Conventional logic & wisdom says there ...
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7answers
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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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2answers
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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 ...
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3answers
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How does an SSL server prove its identity?

This document says that a challenge response authentication proves the servers identity. But is a man in the middle attack still possible if the client does not verify domain name ? Please help me ...
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Basic self-signed certificate questions

A few basic questions around self-signed certificates Question 1 Does a self-signed certificate has to have a CA? I realize that a "real" certificate must as it otherwise can be chain validated but ...
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4answers
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HTTPS self signed certficiate for personal website

I want to make my Synology NAS accessible over the internet. When I create my own certificate and import this on all my devices (PC, Laptop, Smartphone, Tablet, etc.) is this as secure as buying a ...
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4answers
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SSL Client Certificate authentication

Is it possible to make a program which uses client certificate authentication with only public and private key (I have not generated any certificate, I have only public and private key). Simply, I ...
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2answers
1k views

Trying to understand how Digital Certificates and CA are indeed secure

I understand that Digital Certificates and Certificate Authorities (trusted 3rd parties) help prevent man in the middle attacks during HTTPS connections. However, I am confused on a few details. Let'...
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5answers
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How to validate a client certificate

My understanding is that when using a client certificate for security one issues a private and public key cert (for example X509) of some sort and sends that of to the consumer of the service that one ...
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2answers
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Benefits of a wildcard vs per-subdomain certificates

As you might know, Let's Encrypt doesn't offer wildcard certificates and it won't in a short-term because you can just order as many certificates as you want for the sub-domains. This make me wonder.....
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4answers
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Why the symmetric key is added to the message?

Yesterday in my class we learnt how to send a message from Alice to Bob with the achieved goals of confidentiality, integrity and authenticity. In order to have a better performance we use a hybrid ...
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3answers
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Any good free SSL proxy on windows? [closed]

I'm looking for SSL proxy capable of dumping requests. I want to test custom browser against SSL-MITM attacks. I'm able to re-route all traffic ongoing from browser to machine with proxy. ...
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1answer
693 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 ...
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2answers
474 views

What are the risks of installing a root certificate from Facebook on your phone?

I read a TechCrunch article today describing a program Facebook has been running since 2016 where they pay users $20 in exchange for installing a root certificate run by Facebook. This immediately ...
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4answers
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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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2answers
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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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3answers
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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
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What is the purpose/role of the “alias” attribute in Java keystore files?

I've heard conflicting information about the purpose of the alias attribute in Java keystore files. Can someone please clarify on what exactly this attribute is, and what it should be set to when ...
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2answers
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Obsolete cryptography (SHA1) warning although certificate uses SHA256

I ordered a certificate with SHA256 from Comodo and was wondering why Chrome shows this message: Your connection is encrypted with obsolete cryptography. The connection is encrypted using ...
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1answer
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Should the thumbprint be SHA2 in addition to the Signature Hash Algorithm?

I'm looking at a Windows PKI and see that the Thumbprint is SHA1, while the Signature is SHA2 (SHA256). Is this an acceptable configuration? Should I recommend that the client update to SHA2 for a ...
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2answers
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OCSP and CRLs: Specified in CA or client certificate?

Here's an example PKI setup: * Root CA (offline) * Issuing CA * Client 1 * Client 2 I'd like to specify a CRL distribution point for CRLs generated by Root CA, and an OCSP URL for Issuing ...
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2answers
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What happened with Kazakhstan's Root CA MITM policy?

In 2015 there were news that Kazakhstan was going to start intercepting all HTTPS traffic via "man-in-the-middle attack" starting Jan 1, 2016, by requiring kazakhstanis to install their root CA. ...
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1answer
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Manually walking through the signature validation of a certificate

Since I am not too familiar with the Web of Trust and Public Key-Infrastructure I decided to learn about it by following the signing chain of a X.509 certificate issued to CN=*wikipedia.org (Serial ...
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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/...). ...