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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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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1answer
563 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 ...
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2answers
80 views

Issuing certificates to two departments from same ROOT CA so one does not trust the other

Scenario: We have two departments within IT; Say Department-OLD and Department-NEW. A single internal PKI environment exists and a root CA (singular) is trusted by All endpoints. Problem: ...
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2answers
680 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 ...
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730 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 ...
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289 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 ...
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3answers
322 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 ...
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6answers
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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 ...
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4answers
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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 ...
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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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3answers
190 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 ...
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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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2answers
472 views

Are there any downsides to using Let's Encrypt for a website's SSL certificates?

On the advantages side, I see several benefits to using the Let's Encrypt service (e.g., the service is free, easy to setup, and easy to maintain). I'm wondering what, if any, are the disadvantages to ...
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3answers
1k views

Why do we allow SSL certificates to be replaced before their expiry date, without revokation of others?

Imagine a situation where a rogue CA creates a certificate for your site. Since the user's browser trusts the CA, it will accept the certificate without any fuss. However, the site's real certificate ...
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1answer
1k views

Use Client Certificate using Self Signed CA while using Web Certificate of a publicly trusted CA

I would like to ask if it is possible to use different CA for the client certificate and the web certificate? For example, I would use Verisign to sign my web certificate while I use my Self Sign ...
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3answers
702 views

Issuing SSL certificates for device automation software package without domain names

We are developing the automation software for Windows which communicates with the certain devices via our own private connection protocol. That software package consists of several server (including ...
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2answers
338 views

Why firefox shows some connections are not secure?

I am using internet by connecting mobile phone to my laptop using usb. From yesterday,my browser (firefox) shows for all most all website. Why this happen? How can i solve this?
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1answer
2k views

Can a certificate have multiple chains and multiple self-signed roots?

The following MSFT document has this paragraph: All possible certificate chains are built using locally cached certificates. If none of the certificate chains ends in a self-signed ...
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Android Kitkat reports: “Network May Be Monitored by an Unknown Third Party” when using non-default root CA

My company uses a private PKI to handle such scenarios such as Mutual auth (TLS) to a website using client certificates SSL web server certificates on an Intranet (once a VPN session is ...
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1answer
203 views

Design of system based on HTTPS, Client Certificates and custom CA

I have the following system: 2 application servers. At the beginning is installed the first server and later is installed the second one. A client access from a browser to both servers Application ...
5
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1answer
417 views

'Trusted CA Certificates' and 'Trusted remote Certificates'

What is the difference between Trusted CA Certificates and Trusted remote Certificates?
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3answers
1k views

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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3answers
353 views

What is a reasonable expiry for user authentication certificates?

This question is about a nearly decentralized P2P system with a centralized certificate authority where users can authenticate and receive a certificate on their public key and then can authenticate ...
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2answers
4k views

Is an AIA or CRL useful / required at the Root CA if that Root is used to cross certify another PKI?

Suppose I have several independent PKIs that are used Two internal PKIs: One with SHA1 support the other with Suite B algorithms. A partner who I trust and have a policy map with. Since both my ...
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2answers
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What tools exist to help me monitor OCSP certificate validation failures?

The discussion at Why isn't OCSP required by default in browsers? notes that many browsers by default simply ignore failure to check web site TLS certificate revocation status via the Online ...
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2answers
360 views

Is cacert.org more harmful than self-signing?

I don't understand the https security model attempted upon me by The OpenBSD Journal (undeadly.org). Instead of using self-signed certificates for https like they did in the past, they for a while ...
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google certificates correct CA [closed]

I view certificates of https://www.google.com.ua/ So I thought, when requesting via cURL, if I point by CURLOPT_CAINFO to those certificates (GeoTrust Global CA and Google Internet Authority G2 in ...
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1answer
267 views

Security and authentication problem

We have a sample scenario and we would like to receive some feedback and some solutions regarding possible security schemes. First of all, lets imagine a real world scenario: Imagine that a user ...
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2answers
791 views

Is there any research on which SSL certificate authority has the best browser compatibility

We're about to release a service that requires website owners to embed our javascript code on their site which will then serve the script from our server similar to Google Analytics. (yes I'm aware of ...
5
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1answer
249 views

Is my ISP trying to impersonate google?

Everything has been well for years and today I wake up with this: A warning on EM Client (also got the same on my iPhone) that the certificate for googleapis.com isn't valid. And the certificate ...
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1answer
2k views

What OID Issuance Policies are appropriate for SmartCard and Browser Certificates?

I'm investigating issuance policies for SMIME and Browser certificates with different levels of assurance. For the purposes of S/MIME and Browser certificates, should I even use an assurance policy? ...
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1answer
4k views

AIA/CRL locations for Offline Root

I've read the answer to the following "Checklist on building an Offline Root & Intermediate Certificate Authority (CA)" and I have one questions based on the system I am trying building It's an ...
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2answers
91 views

How do I prepare for Certificate Authority end of business?

We are deploying a security solution which uses certificates to validate documents. These certificates are issued by our government-authorized CA. What if in a distant future, the CA who provided us ...
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1answer
14k views

What is updated with “Update Root Certificates” enabled? What is the equivalent in Windows 2008R2?

What root certificates are/are not updated when the following checkbox is checked? Additional questions If I manually remove a root certificate, will this service replace that very certificate? ...
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1answer
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Who is this strangely named Certificate Authority?

I'm researching certificate authorities, and I just have no idea what to think of the CA named x00Ax00-x00Tx00rx00ux00sx00tx00 x00Gx00ex00sx00.x00 x00fx00xFCx00rx00 ...
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3answers
571 views

Certificate Transparency

From what I read here, if the intermediate CA has been compromised, a fake cert can be issued and the privacy of the end-users could be compromised as well. In order to remediate this situation, ...
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3answers
653 views

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 ...
4
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1answer
833 views

OCSP: What is “hackedirl.files.wordpress.com”?

After I ticked that my browser (Firefox) must require OCSP: http://i.stack.imgur.com/UeDXh.png I got a window popped up (several times! And it still pops up.. ~randomly ~about a few 10 minutes): ...
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4answers
527 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 ...
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2answers
1k views

What to do with expired certificates as a CA?

This and this answer says that "once a certificate has expired, the CA ceases to keep track of its revocation status". I'm trying to learn how OpenSSL works as a CA. If I have a revoked expired ...
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3answers
1k views

From a trust perspective, is renewing a CA certificate the same as trusting a sub-CA?

I'm trying to understand the validation logic that would occur in the following hypothetical scenario An unpatched XP user who trusts a list of root CAs. Those CAs in particular have been renewed ...
4
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2answers
304 views

Is authorisation with token secure?

I have a general security question: Let's say there is a client-server application with authorisation by login and password using a secure connection between server and client (https). User can have ...
4
votes
1answer
924 views

Is possible that a TLS server send more than one certificate to the client for the same site?

What I'm trying to archive is enable ECDSA and DSS ciphers in my site, but at the same time not depend just of self signed certificates, so I could sent to my client more than one certificate and them ...
4
votes
2answers
502 views

What is the severity of a fake certificate?

I'm not a security specialist, thus reading this Google Blog post about a fake *.google.com certificate, raises a lot of concerns, if anyone can impersonate a website, especially a google website, my ...
4
votes
2answers
191 views

What is the state of the Windows Update certificate after Flame?

May 28, The Flame malware is discovered in Iran and by Kaspersky Labs. June 5, Dan Goodin (Ars Technica) points out that Flame had hijacked WindowsUpdate, spreading signed malware through that ...
4
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1answer
4k views

Certificate verified using two different paths

StartSSL has an intermediate certificate that they use to sign their EV certificates: sub.class4.server.ca.pem. This certificate's issuer is shown by openssl x509 to be /C=IL/O=StartCom ...
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2answers
755 views

How practical is a certificate's “basic constraint” property in protecting my HTTPS / SSL session?

Suppose a leaf node creates a certificate for a different domain, acting as a CA. Do most popular frameworks, or SSL chain validation tools verify the constraints? Are there any I should be ...
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2answers
50 views

Can a website have multiple valid TLS certs looping back to multiple root CAs in case one of them is compromised?

Sometimes, CAs get compromised, like Diginotar or Comodo. In such an incident, anything can happen from individual certs being revoked to the entire tree being scrubbed from the cert store. A company ...
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2answers
267 views

Explicitly prohibit an intermediate CA certificate on OpenSSL

How do you explicitly not trust a particular certificate (especially, CA certificate) for OpenSSL? On NSS-based applications, one can install the cert with trustarg p: prohibited (explicitly ...
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1answer
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How can I demonstrate that 3 independent root CAs validated my domain?

I am concerned about the hacking of a root CA and want to buy 3 SSL certs from completely different providers who will independently validate my identity. Then at presentation time, I will send all 3 ...