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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6
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2answers
563 views

Could a stolen certificate show as trusted?

I have recently started learning about PKI and have the following question/s. As far as I know a signed certificate contains the domain name of the server that the certificate will be placed upon. ...
6
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4answers
4k 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 ...
6
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1answer
3k 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 ...
5
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1answer
5k 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 ...
5
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2answers
3k views

Dealing with expired or revoked signing certificates with Infopath documents

Suppose I have an Infopath form that is digitally signed today by a valid, and active user. When that user leaves the company, we disable the account and revoke the certificate. This causes a problem ...
4
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3answers
2k views

Intercepting SSL traffic on Android app

I am trying to intercept SSL traffic from my Android app to test the security. I am using certificate pinning in the hopes I can prevent people from snooping. I have tested by configuring ProxyDroid ...
4
votes
1answer
1k views

Would introducing client certificates for a mobile app improve security?

I have developed a REST API which has been configured to only operate over HTTPS. The sole purpose of this API (at least for the moment) is to operate as the backend entry point for a mobile ...
3
votes
1answer
2k views

Purpose of certificates signed and trusted by CA

Another newbie question but I just don't get the purpose of certificates signed and trusted by CA. We already have public/private keys, hash functions to sign/encrypt messages so why do we need ...
18
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3answers
4k views

Anything to do about old gpg keys?

Quite A few years ago (in middle school) I created some gpg keys, published them to a keyserver, etc. because I was l33test kid on the block. Now I have gone through a few new computers and OS's, ...
16
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3answers
2k views

Multi-tenancy, SSL Certificates, and Subject Alternative Name

The X509 specification allows a CA to issue a single certificate for multiple hostnames, by using the "Subject Alternative Name" extension. From the spec: The subject alternative name ...
14
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4answers
8k views

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 ...
13
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1answer
3k views

Renewing Microsoft Certificate Services Root Certificate

We currently have Microsoft Enterprise Certificate Server installed on a domain member machine which issues 1 year certificates to users for authenticating to VPN. We'd like to start issuing web ...
10
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1answer
566 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 ...
10
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2answers
3k views

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 ...
9
votes
2answers
3k 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 ...
7
votes
4answers
2k views

P12 - Extract public part (certificate) without knowing the p12 password

I would like to extract the public part of a revoked P12 which doesn't belong to me. I can't open it with KeyStore Explorer because I am prompted for the password, is it possible with OpenSSL ? The ...
7
votes
2answers
802 views

How do systems protect against a stolen code-signing certificate after the certificate expires?

Imagine this scenario: 1st December 2014 - a certificate is stolen and used to sign malware with 2014-12-01 timestamp. 15th December 2014 - the certificate is revoked. Malware will be prevented from ...
7
votes
1answer
8k views

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 ...
7
votes
1answer
1k views

Choosing an SSL certificate provider

Does it make any difference which provider I get my SSL/TLS certificate from? In particular, what are the pros and cons getting an SSL certificate from Verisign vs getting one from Thawte? Which one ...
7
votes
1answer
3k 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? ...
7
votes
4answers
5k 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 ...
7
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2answers
5k views

What is an intermediate certificate authority?

What is meant by an "intermediate certificate authority?"
6
votes
2answers
1k views

What are the real-time applications of long term digital signature with timestamp

I want to know the real time applications that uses digital signatures with timestamps. Specially I am interested to know the applications where we can trust an old signed document which is now ...
5
votes
2answers
837 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 ...
4
votes
5answers
11k views

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 ...
4
votes
2answers
9k views

OpenSSL, x509: what's the significance of CN (Common Name)?

With regard to these three items Certificate Authorities (CA) Gateway certificates End-point Certificates (client-cert) What is the significance of the Common Name CN with regard to the a VPN? ...
3
votes
1answer
8k views

Why is a CA certificate required for EAP-TLS clients?

When setting up clients with WPA2 EAP-TLS, most clients (ie: my phone, my computer) require both a client public/private keypair (for obvious reasons) and a certificate authority certificate. It's ...
2
votes
1answer
1k 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 ...
1
vote
2answers
203 views

Is it Possible to use one commercial SSL Certificate to issue end user certs?

My organization is preparing to purchase some 50 "units" from Symantec, with which we can purchase Verisign SSL certificates of varying authentication levels. Our organization does not have--but ...
1
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2answers
6k views

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]: ...
13
votes
3answers
1k views

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 ...
12
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5answers
4k 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?
8
votes
1answer
148 views

Browser blacklists & the Symantec-Google Certification Debacle

Background: As explained e.g. on this Google company blog, Google writes that: On September 14, around 19:20 GMT, Symantec’s Thawte-branded CA issued an Extended Validation (EV) pre-certificate ...
7
votes
2answers
441 views

Are any major websites offering ECDSA authentication?

At the time the Cloudflare blog post “ECDSA: The digital signature algorithm of a better internet” was authored, Cloudflare was apparently one of "fewer than fifty" users of ECDSA certificates on the ...
6
votes
1answer
857 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 ...
5
votes
2answers
93 views

How could mobile developers prevent bypassing certificate pinning with tools such as SSL Kill Switch?

I used SSL Kill Switch on some iOS mobile applications to try to bypass certificate pinning and I was successful. I understand that SSL Kill Switch "kills" the certificate validation process on the ...
5
votes
2answers
124 views

Understanding Digital Certification as as a whole starting from a normal http request

I am trying to understand the difference between digital signature and digital certification and how they work as a whole together on a high level perspective. I hope gurus here can point to me if my ...
5
votes
5answers
538 views

How can I explain self-signed certificates to users?

I don't trust certificate authorities, so I'm using a self-signed certificate on my server. The server provides both a website as well as other services. Most modern SSL-capable software, upon ...
5
votes
1answer
1k 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 ...
5
votes
1answer
566 views

'Trusted CA Certificates' and 'Trusted remote Certificates'

What is the difference between Trusted CA Certificates and Trusted remote Certificates?
5
votes
6answers
2k 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 ...
4
votes
1answer
1k views

How would you know a certificate/private key if you extracted it from RAM? Or would you?

Related to, of course, the heartbleed vulnerability, I've been reading the news about the worst case scenario for this attack being the extraction of the SSL private key, because, of course, this ...
4
votes
1answer
416 views

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 ...
4
votes
1answer
453 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 ...
4
votes
2answers
316 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 ...
3
votes
1answer
242 views

Check root certificates and certificate authorities on new PC

First Lenovo was caught shipping Superfish with new PCs, which included a universal self-signed certificate authority, and now Dell has been caught shipping PCs with a similar root certificate. What ...
3
votes
2answers
393 views

Can an eavesdropper detect the use of a TLS client-side certificate?

Basically what the above says, assuming the eavesdropper must be completely passive, and cannot connect to the server to check if the server requires a client certificate.
3
votes
1answer
190 views

How to trust a CA to sign a CRL but not a cert?

In my application, there are many parties that are trusted to revoke a cert (ie by signing a CRL), but are not trusted to sign (new) certs. How do I mark a CA to be trusted only for CRLs, and not for ...
3
votes
4answers
474 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 ...
3
votes
1answer
236 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 ...