A piece of data used in public key cryptography 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.

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'Trusted CA Certificates' and 'Trusted remote Certificates'

What is the difference between Trusted CA Certificates and Trusted remote Certificates?
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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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Public keys without the certificates

There are two clients and a server. Each client generates an RSA key pair and uploads public key to the server. The server associates the public key with the user identifier that is specified during ...
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543 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 ...
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2answers
2k views

How to go about an ssl certificate renewal

I've got an ssl certificate from godaddy, and it's time to renew. I ended up with a single "keystore" file, which I give to my webserver (jetty). This is the process I went through to generate the ...
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4answers
256 views

Trust among the root-CAs

The system of CAs with the root-CAs and their subordinate CAs are IMHO in principle akin to the system of banks with their main sites and subsidiries. In the case of banks, a customer of a bank ...
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286 views

How can I use certificates to secure my webservices? What is available to javascript?

I have a few web services that are accessed over public wifi connections and I think it would be a good idea to issue certificates to encrypt data, prevent MITM, and invalid impersonation (beyond what ...
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2answers
215 views

self-signed certs that aren't the final certificates in the path

The X.509 spec makes frequent statements like this: (b) If certificate i is self-issued and it is not the final certificate in the path, skip this step for certificate i. How can you have ...
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551 views

What is the difference between `extendedKeyUsage` and an application policy?

In some Microsoft articles like http://technet.microsoft.com/en-us/library/cc731792%28v=ws.10%29.aspx, I find some confusing statements like Application policies are sometimes called extended key ...
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Unrecognized leaf certificate

Every 15 minutes or so I get this message in my system.log Apr 25 22:05:36 Ivans-MacBook-Pro.local apsd[194]: Unrecognized leaf certificate Apr 25 22:20:57 Ivans-MacBook-Pro.local apsd[194]: ...
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497 views

How do I constrain Windows Smartcards for AD Authentication so that “anyExtendedKeyUsage” is not implied?

This document describes how there are 3 ways to constrain a SmartCard certificate The Enhanced Key Usage field defines one or more purposes for which the public key may be used. RFC 5280 states ...
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Trying to understand why signatures in root certs “are not used”?

Taken from here: Don't worry if the root certificate uses SHA1; signatures on roots are not used (and Chrome won't warn about them. Why are the signatures not used? Are not root certificates ...
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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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4answers
2k views

Is it safe to send a CSR via email?

I'm new to commercial SSL certificates and would like to know if a CSR that I generate is safe to send via email?
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2answers
667 views

X.509 certificate policies question

I asked another question about certificate policy mappings. This is a different issue. This is about Certificate Policies. To quote from the X.509 RFC: In an end entity certificate, these ...
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4answers
1k views

Why is it a good idea that X.509 digital certificates have an expiry date?

What is the benefit of having certificates expire at some fixed date?
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Should I regenerate new SSL private key yearly? [duplicate]

Im' renewing my certificate every year. Since I have to make a CSR, should I also renew my key pair at the same time, or is it ok to get a new cert with the same key ? Please supply any security ...
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1answer
668 views

What's keeping a malicious man in the middle server from forging a valid certificate

According to process of authenticating a server certificate: What's keeping a malicious server to fill up a valid server certificate since it knows all the things: Forged Server public key (man ...
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3answers
800 views

Digital Signature and Verification?

AFAIK , When Alice wants to write a message to Bob -- she uses Bob's public key and encrypt the message - and then Bob - using his private key - use to decrypt it. So public key is used to decrypt ...
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2answers
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Adding custom data in X.509 certificate

I am using SSL with client authentication. I need to send some extra data while sending the client certificate? Can I send it in the certificate? Can I use the extension fields in certificate for that ...
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1answer
223 views

What issues might exist with TLS-OBC's emulation of Browser Certificates?

TLS-OBC is an RFC proposal that increases SSL/TLS security by using certificates on both ends of the TLS connection. What's special here is that the client is permitted to dynamically create a local, ...
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3answers
360 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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2answers
166 views

Using a verified certificate to sign others

This relates to PKI and certificates generally but websites more specifically. Could you get a verified certificate from a CA that is signed and fine for use, and then use it to sign your own ...
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2answers
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How to create an Apple Installer Package Signing Certificate

How can we create a certificate with the following Extended Key Usage extension using OpenSSL? Extended Key Usage extension, critical, with a purpose containing Developer ID Installer Package Code ...
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2answers
661 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
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What is an intermediate certificate authority?

What is meant by an "intermediate certificate authority?"
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342 views

Why is a CSR hashed?

What are the use cases for defining something other than the default SHA1 hash in a CSR? Is it to protect the digital signature, public/private keys? What is it protecting exactly?
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Isn't this the same as using a certification authority?

Taken from Wikipedia, here is the pretext to my question: A certificate authority (CA) is an organization that stores public keys and their owners and every party in a communication trusts this ...
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139 views

Is it a good idea to generate certificate-specific CRLs? What is this technique called?

Suppose I create 3 certificates with the following CRLs Cert1 http://crl.server.com/batch1/root1.crl Cert2 http://crl.server.com/batch2/root2.crl Cert3 ...
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1answer
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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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4answers
307 views

Why self-signed https is less trustworthy than unencrypted http?

It wouldn't be far-fetched to guesstimate that at least 50% of the web traffic can be intercepted in 2014. However, a guesstimate of active interception attacks is likely an order of magnitude ...
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1answer
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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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3answers
209 views

How can I know when a certificate was created?

I want to know whether my various providers changed their certificate because of Heartbleed, or they are using an old vulnerable certificate. How can I know that? Is the "valid from" date also the ...
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2answers
195 views

Can I buy a signing-valid certificate for internal use?

So now that I have to implement "secure transport" as defined by The Direct Project (not to mention reinventing a bunch of wheels, but that's another story for SO), I find myself staring down the ...
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1answer
485 views

What happens to a certificate's Basic Constraints when a policy map is used?

One feature of a Basic Constraint when applied to a certificate (CA or end certificate) is that I can specify the maximum number of CAs that are permitted in the chain. I'm planning on having a 2 ...
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2answers
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How to use 'key material' so that multiple people can access protected files?

I'm not sure if this is the right SE to ask this question, but it seems more I have a database of files that needs to be encrypted such that multiple people with different passwords/logins to this ...
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1answer
241 views

Risks associated with distributing encrypted private key with our software?

Our software contains two executables that need to serve data over SSL (and several that need to do requests over HTTPS)). I notice that it is distributed with some .PEM files created with OpenSSL. ...
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1answer
258 views

Generate CSR with 2 OU Names

I have to create an application which generates a CSR. While generating a CSR we are required to fill in several details like CN, OU, etc. The problem is that the Certifying Authority to which I have ...
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494 views

How to troubleshoot why Thunderbird rejects a PKCS#12 certificate with “Could not verify this certificate for unknown reasons”?

After playing around a bit with openssl, I created a PKCS12 certificate which imports flawlessly in Firefox while Thunderbird "Could not verify this certificate for unknown reasons". Talk about a ...
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1answer
277 views

Signature and Timestamp for Long Term Document Archival Question

I have a PDF document intended for long-term (many years, maybe decades) archival which I would like to digitally sign with my personal certificate to ensure its integrity. As far as I understand, I ...
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1answer
4k views

What are the OIDs (KU and EKU) necessary for Smart Card Authentication in Windows?

MSFT smart card authentication is listed in PKINIT RFC 4556 however I don't see any OIDs listed. Based on this and this KB article the EKU section of the certificate should contain "Client ...
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150 views

Can IE be made to imitate the behavior of Chrome's KeyGen element?

Is there any way I can repurpose existing ActiveX controls or functionality to get IE to work with the KeyGen element? Assistance getting Safari to work with this optional HTML5 spec would be ...
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4answers
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Does a renewed certificate open old messages?

I have a digital certificate that I use to exchange messages with peers, my certificate expiration date is due next year, suppose I renew this certificate before it expires, will I be able to open the ...
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1answer
212 views

Authentication methods without trusting 3rd parties unless explicitly indicated

The plan is to have a situation in which no third parties have to be trusted unless you explicitly indicate so. For example CA's are only used when the contact explicitly added the CA as a trusted ...
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2answers
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Generate openSSL certificates from within C code using commands?

This is an openSSL command for generating a private key and a certificate, openssl req -out CSR.csr -new -newkey rsa:2048 -nodes -keyout privateKey.key The question I have is whether there is some ...
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Is TLS-in-TLS supported in any software? Does it make sense? [closed]

I got fun idea how to increase the security of the SSL (TLS) for websites. However I think there is no support for it in the browsers, so I thought I could add it eventually, but have no idea if it's ...