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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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 ...
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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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742 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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126 views

Is using “SHA-256 with RSA-2048 Encryption” a secure certificate hashing algorithm?

Is using "SHA-256 with RSA-2048 Encryption" a secure certificate hashing algorithm? I don't think it is. Two examples: nsa.gov [careers site] give.wfp.org
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64 views

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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110 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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99 views

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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4answers
1k views

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: ...
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1answer
62 views

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 ...
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2answers
133 views

What exactly is IE / Chrome checking when I view the “certification path” tab on cert connection details?

When I bring up certificate details for a web page in IE or Chrome, I have the option to view the certificate hierarchy (under a tab called "Certification Path"). Here's an example for ...
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107 views

Should self signed wildcard certs be used?

I think this is more urban legend around where I work than anything. I do not see anything in RFC 2459 that specifically says whether or not they should be used or if there are any known problems with ...
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229 views

How to extend x509 certificate validity

I have two x509certificate, and now they are expired. What I would do is to extend the validity date of these certificates (I don't want t creat new one). Can I do this with openssl or other tools ?
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56 views

Using a minimal set of certificate authoraties

It been known for quite a while now that SSL is more of a security-illusion than a real one. As it's not completely useless, and there's no real alternative at moment (though convergence looks ...
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1answer
1k views

How to generate self-signed EV SSL Certificate?

I configured XAMPP / Windows on my laptop so that this URL: https://www.supersite.com/ points to XAMPP / localhost rather look elsewhere. I basically generated a self-signing certificate, imported ...
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243 views

Is a self-signed SHA-1 certificate sufficient security for a company transmitting sensitive data?

We recently decided to pay an ISP (a substantial sum, mind) for a managed internet service up to and including the router in our head office. Part of the initial discussions made it clear that ...
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65 views

Possible to change the CA that a keypair is using?

Pretend I take the same CSR and send it to two different CAs as described in the following scenario: I create a CSR on Windows I submit the CSR and edit my SAN names. Request is pending at the CA ...
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2k views

Does Renewing SSL certificate change its thumbprint / Fingerprint

I would like to know, if renewing a SSL certificate will change my thumbprint? The certificate has expired. If it can be same then under what conditions can it remain same. Many thanks in advance.
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477 views

Uploading pfx certificate to Azure

In order to use SSL with a custom domain in Azure Websites you must upload a pfx file with your certificate and private key to Azure. What are the ramifications of trusting Azure with the private ...
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2answers
303 views

Does a self-signed certificate offer more protection than a public key?

I'm having a hard time finding the practical benefits of transmitting a self-signed certificate over simply a public key. I understand that a self-signed certificate proves the integrity of the public ...
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2answers
178 views

SSL for only parts of a website… How does it work?

I understand that CAs issue certificates based on common names (CNs) like www.amazon.com and that certs are not based on URLs like www.amazon.com/stuff. How is it that when I go to www.amazon.com, it ...
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2answers
373 views

How do proxy servers protect their SSL certificates?

Suppose that there is a http proxy server outside the firewall of an organization hosting a web server. All client connections to the web server happen through this proxy. The client negotiates SSL ...
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4k views

client SSL authentication .pem file and .crt files

So I have minimal knowledge of security really but I'm a primary developer on an application which handles some sensitive data that we want to be secure. The application communicates with one other ...
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102 views

Mechanisms to offer inexpensive https to all second level .wiki domains

I'm working with the registry for .wiki, a new generic top level domain set for public availability in June 2014. We're going to be giving away hosted wikis to registrants of .wiki domains and I'd ...
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3answers
377 views

Using public/private key without signed certificate

I am working on a java program and I am now working on its network security. I want to use a secure connection since it transfers a lot of sensitive information. On all security guides it is mentioned ...
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1answer
739 views

Server not requesting for certificate in SSL handshake

I have one windows service and web service trying to make a web service call over TLS. I have setup the certificates in MMC and I am able to successfully connect using the web service. However, when ...
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2answers
138 views

non-MiTM Reverse SSL

Do non-MiTM Reverse SSL Proxies exist? Or do all proxies that do SSL-SSL mappings decode and then re-encode HTTPS traffic? If this is the case and I want to map https://mypublicdomain.com -> ...
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592 views

x509: must the signature algorithm and public key algorithm match?

I'm having trouble getting Firefox to send an encrypted message using a certificate, and I've found that the only difference between this one and others that work fine are that this one has a DSA ...
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2k views

How to test for OCSP?

I have to test OCSP feature on a SSL server. Since it is a pretty standard feature now, I was looking around for tips on test plans/setting up OCSP responder etc?
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376 views

certificate based network authentication

In certificate based network authentication, is the user tied to just the system the certificate has been installed on such that if he tries to authenticate using another system access is denied?
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897 views

Behavior when validating an expired certificate chain

I have the following situation: A server certificate (CServ) is signed by self-signed certificate (C0) A client certificate (CCli) is signed by CServ Client's trust-store contains C0, so the client ...
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1answer
455 views

What makes a secure smartcard secure? Is contactless/RFID better?

In short what security features exist that I should look for in a smart card? What physical features exist, which are important? It appears smart cards may exhibit different levels of wear and ...
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5answers
92 views

Best Option for SSL Certificate for 2 Domains + All Subdomains

I am hosting multiple websites on my Mac Mini server (latest version). For some reason OS X server does not support multiple SSL certificates well for websites, and after hours on the phone with ...
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2answers
26 views

Mandadory checks a client should make to verify a ssl/tls certificate [duplicate]

Let's say I have a client, not a browser, that wants to connect with https to a server. It could be a python program, an android app or a library etc. Suppose the client has a list of trusted CAs and ...
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1answer
30 views

SSL certificates for a mixture of subdomains and top level domains [closed]

In order to provide https-enabled access to several (e.g. around 5) subdomains and several top level domains on different IPs. Which of the following approaches is technically feasible? a one-use ...
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60 views

What are the steps to take after adding an invalid certificat authority?

in order to pay my bills online internet , I have to go through the website for my internet provider , type the login and password then I redirect to a page your connection is not private i proceed to ...
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1answer
18 views

Conditions for reusing client certs in TLSv1

In my setup I am using client certs, and the client devices are iPhones running iOS 9.0. In comparing some network traces I noticed that in some cases, the server asks for the client certificate for ...
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1answer
71 views

ECDSA implicit certificate using OpenSSL

I am trying to generate implicit ECDSA certificate only for signing and verification using OpenSSL. I tried google but I am getting many research papers. I understood that A messages need to be signed ...
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1answer
119 views

What can a trusted certificate do?

I am doing some reading about security on mobile applications because I found an article about Man in the Middle Attacks. I saw in that article and in many other places (including ...
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1answer
223 views

SHA2 certificate and TLS cipher suites compatablity

I have a server which is configured to use TLS 1.0, 1.1 and 1.2. The server is configured with a certificate siged by SHA-512. The server supports only these cipher suites: • ...
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97 views

Application that uses USB token to assign user on a server

I have the following situation: One user with a USB token certificate access a site and log-in using this certificate, the logging process ask for the USB token password; When the user is logged he ...
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1answer
85 views

Are fields of a root CA certificate checked?

During SSL server validation, it seems that the only fields of X509 certificates found in trust stores that are actually used are the "Common Name" and the "Public Key". I'm not talking about any ...
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41 views

Prevent credential roaming for certain accounts/certificates?

I want to use credential roaming in Windows 7, 8 and 10 for EFS certificates, so users can access their encrypted files from any computer they login to. However, some of these users will also have ...
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1answer
81 views

How to read certificate chains in OpenSSL

I'm trying to understand how to read the output of OpenSSL commands. Currently, I am trying to understand how Certificate Chains work. When I give the command (using a standard ca bundle) openssl ...
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2answers
162 views

Generate CSR and private key with password with OpenSSL

I am using the following command in order to generate a CSR together with a private key by using OpenSSL: openssl req -new -subj "/CN=sample.myhost.com" -out newcsr.csr -nodes -sha512 -newkey ...
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1answer
44 views

Find the Encryption Key (used for network encryption) assuming a Trust Chain is being used on Windows?

If I double click on a .crt file, in Windows, I'm presented with three tabs General, Details, and Certification Path. I'm aware that the Certification Path tells you the details of which root and ...
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1answer
40 views

If You Use Secure Sites with Extended Validation Certificates How Much Do You Still Have To Worry About Phishing Sites Impersonating Them?

Was mulling over the issue of protecting users from password-stealing phishing sites when an interesting question that hadn't occurred to me before popped into my head: Let's say that I decide to ...
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2answers
165 views

Will a wildcard SSL work properly for an A record subdomain pointing to another domain/website?

Client has wildcard SSL for his domain/subdomains. The application we are building is on one of our linux servers using one of our IP addresses and is contained within an account named ...
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217 views

What if the Local Windows Cert Store is Compromised?

The diagram below illustrates chaining digital certificates up to a publicly trusted Root Certificate: I have been researching how trusted root authorities (such as GlobalSign or Verisign) are used ...
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2k views

How to know if certificate is self-signed

How do I find out if a certificate is self-signed or authorized by CA? Somewhere I read that self-signed subject and issuer will be same, is it correct?