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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Is it possible to use same certificate on several machines by exporting it?

My bank proposes certificate. They say I will be able to use it only on one computer. I don't understand: can't I use same certificate on several machines by exporting and reimporting it ?
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valid intermediate certs not in browser

Say an X.509 cert is signed by an intermediate cert that's not in your browser. Maybe the root certificate is but not the intermediate cert. At that point it seems like a valid certification path ...
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64 views

Subject Alt Name certs

Is it ok to specify subdomains in certificates that support SAN. For example base domain is example.com and I want a.example.com, b.example.com, and c.example.com to be included? What is the primary ...
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324 views

Are there any security disadvantages of using production SSL certificate in non-prod environments?

My client has a wildcard certificate *.thierdomain.com that they are using for half a dozen of production web sites. For each of theses sites there are duplicates in several environments, dev, qa, ...
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886 views

Can public certificates be password-protected?

I've only seen private key files (.pfx, .pkcs12) being password protected. Someone told me public cert files (.cer) can also be password-protected. Is that true? Is it also true to say any certificate ...
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239 views

What is stopping me from replaying an SSL certificate?

Say I have the SSL certificate for google.com. I intercept it, edit the certificate with my own domain name and public key and use it to intercept all traffic to google.com. What mechanisms exist in ...
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Server + Client certificate vs Server certificate + Client password

There are three different ways how TLS (1.2) can be used: server and client authenticate, only the server authenticates or neither authenticates. If neither server nor client authenticates using a ...
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“A third party is capable of monitoring your network activity” with [imported] certificates?

I installed the CAcert root certificates on my Android device (which is not rooted), so that I could visit websites with server CAcert certificates without getting the "certificate not trusted" ...
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How to prove the integrity of a digital file if certificates are not an option

Certificates are a fantastic way to prove the integrity of a file - provided that they have been signed from the beginning. This methodology can prove the files authenticity, in addition proving it's ...
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253 views

SSL-certificates for overlapping domain regions?

Suppose, a server hosts https://www.master.com/ and thus is equipped with a (single domain) SSL certificate. Furthermore, suppose there are some web apps below master.com: http://wiki....
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Should each service running on a domain have a separate certificate?

I have a domain name with dynamic DNS (DDNS) for my home server on which I expose multiple services (web server, wikis, issue trackers, etc.) online. Some services are hosted by the same software (e.g....
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45 views

Do not trust all intermediate certificates

I have a trust store containing SSL certificate chain up to Root CA certificate: Root CA -> Intermediate CA - SSL certificate According what I saw as a best practice, only Root CA certificate should ...
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182 views

What does browser do when it queries xxx.example.com and it gets a certificate for yyy.example.com(top level domain is same)?

The question is actually about what level of validations browser does when it gets certificates of some other domains like case 1: Accessing abc.google.com and got def.google.com case 2: Accessing *....
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138 views

Why/when would a CA make a generated public key available to the public at large?

I'm confused about this section in my CEH security exam training material: A CA is able to perform a number of roles in addition to the validation process outlined here. Some actions that a CA is ...
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99 views

How to determine which Browser Certs to reenable on a per-case basis?

Considering that there is no way to actually see which certs that I use in my regularly-visited websites, I've decided to disable all certs and re-enable them on a case by case basis. This is for the ...
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69 views

Use DANE to authentify mail sender

I have my own virtual DNS infrastructure, from the root to the mail server mail.example.com. Everything is signed using DNSSEC. client1@example.com can send email to client2@example.com, digitally ...
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Do all non-CA certs have to be End Entity certs?

Still learning the differences between certs. Can someone explain? The internet has so far been surprising not lucid in describing certificates. *EDIT to clarify EE
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In detail, how does SSL offloading/acceleration/termination work?

What is the in-depth working mechanism of SSL offloading/termination? I could not find literature that would dive deep enough into the subject. Assume the following example, where a intends to ...
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SSL interception with Burp Suite using Firefox - Strange behavior when intercepting twitter

I am learning Burp Suite(Free Edition v1.6). I have set it up with the default settings. The proxy listener is listening to 127.0.0.1 on port 8080 and Certificate option is set to 'Generate CA-signed ...
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352 views

SSL Certificate Trust Model

I have been looking at the SSL Certificate Trust Model, and there is something that does not make sense. If I am correct, the trust model makes it that if there is a chain of certificates with a ...
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Error code: sec_error_untrusted_issuer

I need help with a security issue concerning this code that has just been popping up recently as I visit my favorite websites. Based on some past history I KNOW something is not right, and I am not ...
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openssl, create RC4-SHA certificate

gmail.com Google, fb,... use RC4-SHA. How does one create RC4-SHA self signed cert ? Or even with aes128 key ? I tried using using "genrsa -aes128", resulting cert was DHE-RSA-AES256-SHA openssl ...
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Best Practices for Storing Digital Certificate

I'm building an application where certain sensitive files need to be digitally signed before being stored in the file system using ASN.1 encoding, so they can be verified against a digital certificate ...
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How do websites prevent certificate forgery?

I have recently developed interest about Wireless hacking, and I have seen in many instances in videos and stuff that people are (or more correctly, were) able to perform some kind of MitM attack ...
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141 views

What SSL certificate do I need?

I have 2 domains, one where the website is hosted (lets call it www.a.com), and another (lets call it www.b.com) which has a CNAME record pointing to the first one (www.a.com). Which one should have a ...
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Why does Windows windows suggest/have completely different (and seemingly valid) intermediate CA certs for a given leaf cert?

Is it normal for multiple intermediate CA certs to have the same Subject Key Identifier? Why does this happen? I always thought that this was a unique attribute. I have come across some odd cases ...
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Verification of client certificates

I've read a lot of articles about client certificates. Please correct me if I'm wrong: client certificates are issued using CA CA could be created by myself (self-signed) or bought client ...
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Find private key from private certificate

I have a private certificate from my email server in order to sign emails. At Section "Your S/MIME Personal Certificate" I can view my: private certificate public certificate My public certificate ...
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SSL/TLS certificates that only certain users can use to talk to my server

are there something like SSL/TLS certificates or other equivalents which could allow only certain trusted users (from the internet) who have my server credentials in their browser to access my web ...
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415 views

Cannot connect using ECDH-RSA-AES256-SHA

I try to establish an SSL connection using the ECDH-RSA-AES256-SHA cipher using OpenSSL, but it fails saying "no shared cipher": On the server, I run: $ openssl s_server -cert selfsigned_cert.pem -...
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107 views

Certificate expiry validation - in what stage?

I'm implementing certificate expiry validation for a client. I'm not sure about the following. Is there a standard/popular implementation regarding the order of validation- Check if the ...
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131 views

sftp first connection before exchange cert

If a client connects for the first time to a server via SFTP, the first connection before receiving the server certificate is transmitted in the clear?Let me explain: it is assumed that the client ...
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214 views

Can revoked certificates be “lost” if the base CRL is updated before expiration?

Assumption Suppose I have a CA that issues a base and a Freshest CRL. I also understand the Freshest CRL to be a Delta of revoked certs in the base. I also understand that clients should pull the ...
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180 views

Will CA's still validate internal IP's in SSL certs?

Just wondering what Certificate Authority (CA) policy is nowadays on validating someone's internal IP address in a certificate? I have heard that some CA's used to do this but won't anymore.
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How does a browser choose which certificate to use if my web server has multiple certificates?

I'm using Apache 2.4, with two certificates, one RSA signed by CACert, and one ECC self-signed. Neither of these certificates provide a path to a broswer-trusted root certificate. My question is ...
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When visiting an HTTPS page for the first time, why isn't there a prompt for the certificate?

I installed a fresh Windows 7. I wonder why when I visit website using HTTPS, I do not get asked to accept their certificate like shown on this picture:
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My certificate seems fine but my TLS fails (Cert not validated)

I set up my certificate for my mail server at https://mail.xxxx.com/ I exported my certificate as described in my mail servers documentation and pointed to it in the server settings. The certificate ...
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SSL Server Certificate optional

In RFC 6101 (Of SSLv3), In page 22 ServerHello Certificate is marked with * which means optional or situation-dependent messages that are not always sent. It means that Certificate is optional in ...
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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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Howto pass overly protective corporate firewall

My Corporate Network was always being monitored, but a few days ago they started to block and censor all HTTPS traffic. Recently IT guys forged certificates for all major HTTPS web sites and acts as a ...
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Does critical SubjectAltName IP:x.x.x.x on an SSL client certificate limit where the certificate can be used from?

I have a requirement to limit SSL certificates by source IP. Would setting a critical SubjectAltName limit this (server side validation is by OpenSSL via nginx)? If not, how could this be implemented?...
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3k views

Sending Client Certificate to Server

I have a simple question. Is a web browser sends client certificate to the web server on demand(means web server is configured for client authentication and demand the client certificate) or just ...
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751 views

Additional security for WebRTC/DTLS-SRTP with PGP?

I am having a thought experiment. Can you help me? Two clients who both use PGP. They initiate a WebRTC call using DTLS-SRTP via a 3rd party server. Is there any benefit of encrypting, via their ...
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149 views

Challenge Response across several hops

This is a follow-up question to "When should I use Message layer encryption vs transport layer encryption". I need to send a certificate from the mobile phone to the server. Regardless of all the ...
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40 views

Can we provide our external certificates to a customer's SQL Server for SSL?

In designing hosted software that interfaces with a client's SQL Server over TCP/IP and we may wish to offer the option of using SSL/TLS. One architecture that seems attractive is where we generate a ...
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Do secure ciphers break multi-domain certificates?

In the past days, I was halfway successful with securing my websites. So far, I have achieved the following: Get a certificate from letsencrypt.org, securing the domains example1.com, example2.com ...
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118 views

What server software uses .der?

So apps linked against openssl uses PEM, and Windows generally uses PKCS12, but I haven't seem much .DER in the wild - what server software uses DER?
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TLS 1.2 mutual authentication certificate based standard

I'm running an analysis on a TLS1.2 mutual authentication certificate-based client-server implementation and I'm wondering if there's a RFC or a reference document covering the handshake process when ...
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SHA-1 deprecation and self-signed certificates

I am confusing regarding SHA-1 deprecation. We use self-signed certificates signed with SHA1 and the expiration is after 1 January 2017. According to this blog: http://blogs.technet.com/b/pki/...
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Relationship between SSL cert database and that at the CA site

Say I am using a trusted third party CA site to manage my cert. I created a new cert called CertA at the CA web interface, downloaded the signed cert and use it on my web server. Some time later I ...