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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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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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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3answers
251 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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1answer
304 views

How can I verify if a website revoked its old SSL certificate keys? [duplicate]

Through reading from multiple sources and watching Security Now's How the Heartbleeds, I have come to the understanding that the following procedure is recommended to be safe from the Heartbleed ...
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1answer
255 views

Which signing key should I use for certifying other peoples public keys: master or subkey?

I have a Master Identity key (which is detached from my daily-use keyring) and both encryption and signing subkeys (all are RSA). I sign documents with the signing subkey: GnuPG selects this key ...
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Is there an SSL / TLS Certificate state-cache on Windows, IE, and Outlook and how it it managed?

Today I changed the SSL certificate that 3,000+ Outlook clients are using. In doing this I changed the certificate to an "older" one that had the same subject name, expiration and everything else. ...
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How to set “Not Before” value to past when creating certificate request

We have lots of embedded TLS clients on the field. TLS Servers must be authenticated. Because long power cuts may reset clock of those devices, we have requirement to use certificates with validity ...
7
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1answer
117 views

What considerations should apply for self service Renewing, Revoking, or Unrevoking a certificate?

I need to design a self service portal for renewing, revoking, and unrevoking a certificate and have come up with the following rules*: Renewal Certificates have a short term validity and need to ...
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1answer
974 views

How does an end user differentiate between OV and DV certificates?

This is a very good link that explains the different types of SSL certificates and level of trust provided by them. An Extended Validation (EV) certificate it is easily identified by the green color ...
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1answer
4k views

Reset Windows trusted certificates store to its default

Over the time I have installed several additional trusted CA certificates to Windows trust store, sometimes because an app pushed me to do so, some other times for development and testing. Is there ...
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1answer
714 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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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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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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3answers
252 views

Renew digital certificate

If I have deployed a digital certificate on a webserver and if it needs to be renewed then what steps do I need to follow? Will I need to generate a new longer public key private key pair? Why do ...
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3answers
5k views

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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5answers
334 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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3answers
3k views

System time and certificates

Recently I accidentally changed the system time to a different month, and then I surfed to a secure site. I got a warning from Google Chrome that mentioned my system time and said the certificate ...
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585 views

Personal digital certificate how to verify

A server certificate would have its domain name at its subject field. A personal certificate would have your name as the subject field. How can you be sure that there are no two certificates with the ...
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2answers
527 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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4answers
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Adding self signed certificate to trusted store

I have been reading about certificates and often is said that self signed certificate should not be added to the trusted authority store and even if you did, remove it after usage immediately. MSDN ...
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3answers
407 views

Why are CA's signing keys available on the internet

I am not very knowledgeable about CA certificates, but I thought these things mainly said "The public key for bank X is Y, and this is verified by CA Z". Once you've bought this certificate, there is ...
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3answers
1k views

Certificate chain

For my computer to verify the identity of a certain certificate should it have all the certificates up to the root certificate?
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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 ...
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1answer
4k views

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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VPNs vulnerable to MiTM because ANY certificate goes

I spoke to a sysadmin in a business center today who intended to basically perform a MiTM (as he called it) on every connection in his network because people in his office building are using VPNs and ...
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4answers
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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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388 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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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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1answer
4k 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 ...
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2answers
795 views

ASN.1: ENUMERATED vs INTEGER

From the X.509 specs: CRLReason ::= ENUMERATED { unspecified (0), keyCompromise (1), cACompromise (2), affiliationChanged (3), ...
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3answers
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How and when should I use OpenSSL for IT Security? How do I understand the output?

I'm discovering OpenSSL, and already used it to diagnose a faulty SMTP TLS connection, but I'd like to get a better / full understanding of the tool and how to use it. What resources should I use ...
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2answers
921 views

Why do embedded systems store server's public certificate in ROM?

In the home automation scenario, smart gateway can bridge the many smart devices with Internet. In many cases, a server's public certificate is stored in the embedded system's ROM during ...
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3answers
660 views

What risks would exist in transmitting an encrypted PKCS12 via Https

I have a scenario in which I would like to automate the deployment of client certificates generated by an issuer I control. The approach I am considering is given below, and I would appreciate ...
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2answers
297 views

How protective should we be of an SSL client certificate?

We've got an application where the database connection requires an SSL client certificate. How protective do we need to be of this certificate? What are the implications if someone else gets it? I ...
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2answers
905 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
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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
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SSL Cert Types and Key Usage

I want to use OpenSSL to create a CSR and submit it to my CA (which uses Microsoft PKI) and receive certificates that can be used for both Server Auth and Client Auth. I'm not clear on a couple of ...
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2answers
914 views

Two certificates on smart card

I have a question regarding Swedish gov eID (but I guess it is a pki/smart card general question); Why is there two certificates/keys on the card? Background: In Sweden you can have a "citizen ...
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2answers
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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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2answers
521 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 ...
6
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1answer
321 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 ...
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1answer
1k views

How do I learn Cryptographic/Mathematical notation

I asked a question earlier where it was recommended that I describe my issue using standard cryptography notation. How do I learn this notation and how to convey my approach? How can I annotate this ...
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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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3answers
7k views

What data should I validate when validating X.509 certificates using Java?

Well I began with PKI a year ago with RFID system at school. Now I'm asked to implement this in my job. I understand most part of the idea. The doubt is about the certificate validation. I know it ...
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2answers
1k views

Website Certificate Revocation check - Big deal? [duplicate]

As I was about to make payment for my flight ticket, I noticed something strange with the British Airways website's SSL cert. My browser (Google Chrome) was unable to check whether the certificate has ...
5
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4answers
3k 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 ...
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3answers
5k views

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
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Does checking the fingerprint of a self signed certificate improve security?

I am currently developing a component for an application that does TCP communication with a device inside a local area network. I use TLS to provide data encryption, integration and authorisation. ...
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4k views

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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3answers
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How to distribute client certificates without exposing private key?

I'm desgining a B2B web service based on WCF. As the number of clients is relatively small and security is a priority, i have chosen to go with X509 client certificates for client authentication. I'm ...