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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Evaluate the signature of an X509 certificate in .NET

This is my scenario: A CA signs a certificate with its private key and sends it to a client via https response. From this response the client creates a X509Certificate2 class, that represents the ...
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139 views

What are the benefits (if any) of changing TLS certificates frequently?

As I understand it, a certificate is used only for verifying the identity of the server. Are there any security benefits for changing them frequently (once a week for example)? If this is done so ...
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688 views

Wildcard SSL Certificates & SAAS

From what I have read, using a wildcard SSL/TLS certificate is not advisable, how do you do certificate issuing & management in your SAAS application(linux) where each client has a user selected ...
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513 views

Security Certificates - Tools to Generate Security Certificates

I want to create a self-signed certificate that will be installed as a trusted certificate authority. I then want to create another two certificates which are signed using the private key of the ...
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236 views

How does a function certificate work?

Say that we have a client / server solution (written in .NET). If we want to use a certificate for the TCP communication, is it enough to use one function/service certificate to encrypt communication ...
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707 views

SSL: How to send generated client certificate from server to avoid MITM?

The question I have is simply how do I prevent a MiTM attack on a certificate once the server side creates a new one and tries to send it to a client? Does the certificate get encrypted by rsa and ...
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HTTPS verification failed - get certificate information iPad/iPhone

I went to log onto my bank's internet banking website this morning using Google Chrome browser on my iPad. I get the red error message of death. I can't figure out why. It's happening on both my ...
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1k views

Revoked certificate validation using past times

I'm working on XAdES implementation for Java, as such I require cryptographic implementation to be able to verify certificates in the past. Unfortunately I have problems verifying revoked ...
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374 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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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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134 views

CSR generation origin?

Platform: Windows 7 x64 Development: .NET 4 Web Server: HttpListener (IIS not installed, will not be installed :) ) Can Machine A generate a Certificate Signing Request for Machine B and have the ...
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51 views

Can I revoke a client certificate using only it's serial number (not it's crt/pem)?

I've signed and issued some client certificates with my CA. I can now revoke them like so: openssl ca -name ${CA_NAME} -revoke ${USERS_DIR}/${USERNAME}.crt -keyfile $SSL_PRIVATE_DIR/ca.key -cert ...
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81 views

How do “certificates” hold “keys”? [duplicate]

I am new to the realm of security and keep hearing about "certificates" containing "keys". But no one has been able to actually explain to me what is actually meant by this. I assume that the ...
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74 views

DNSCrypt-proxy: This certificate looks valid

I have just installed dnscrypt-proxy and dnsmasq with DNSSEC but I get a strange message in the logfile from dnscrypt-proxy. [INFO] + DNS Security Extensions are supported [INFO] - [dnscrypt.eu-dk] ...
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130 views

Can an Android malware install a SSL/TLS certificate into non-root devices?

Does there exist some standard API that allow an Android malware to download and install a SSL/TLS certificate as RCA, in the default keystore, in non-root devices? I think that this is a very ...
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513 views

Difference between certificates with “extension fields” and “Non Repudiation” usage

For example we have two certificate pairs: First pair: Server cert with "Non Repudiation" (sometimes called Content Commitment) usage, Client cert without any "extension fields". Second pair: ...
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754 views

Squid SSL Bump - getting “unknown issuer” despite having certificate, do I need CA?

I am using pfSense on the gateway of my network. I configured Squid and enabled the HTTPS filtering. I created the internal CA and configured Squid to use this internal CA for SSL Bump. Now the ...
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295 views

Client side certificates in IIS for accessing a web app only from an specific PC

We have an ASP.NET web app running in IIS, with about 200 users, some are inside our LAN and other ones are outside our LAN. Every user has a userid account and a password to login. Besides those ...
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696 views

Determine private key size using public certificate [duplicate]

I have a public certificate in a PEM (.pem) file -----BEGIN CERTIFICATE----- MIICsjCCAZqgAwIBAgIJAMA1YIQ2JLXDMA0GCSqGSIb3DQEBBQUAMBExDzANBgNV ... 29V/R9RZOoSBHDzGPL84wm4qojMuwQ== ...
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1answer
149 views

Can I modify my certificate chain?

I've had SSL/TLS running on my site now for a while. In order to learn a bit more about general PKI, I studied Qualys' SSL test, and optimised my configuration (including the adoption of OCSP ...
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1answer
64 views

Possibility of using CA as an attack point by governmental organizations under their pressure

I was always concerned about the model of trust behind CA stuff we use . Well, for most of us, it is OK to trust them, since they are reliable organizations with a bunch of solid experience. ...
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205 views

Would it be possible to use cookie to store SSL Client Certificate?

Lately, I was reading that article about SSL client certificate. Why is nobody using SSL Client Certificate? The answer was to that question was : In the current state, this excellent idea is ...
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2k views

Bitdefender Antivirus SSL Cert substitution

I am using Bitdefender AV 2013 ed and I have noticed that when the Scan SSL is enabled in the configuration BD will use a local certificate, as mentioned here. This modifies the cert chain with BD as ...
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1answer
551 views

How do I get a third-party-signed ssl client certificate?

I've been given a requirement of providing a client certificate to authenticate between two application's web services. The other application (that I don't host) is requiring an SSL client certificate ...
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416 views

Diffie-Hellman certificate verify message

On the RFC 6101, about "Certificate Verify", I read that: "This message is used to provide explicit verification of a client certificate. This message is only sent following any client ...
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How does the SSL connection protocol work with self-signed certificate?

I'm using the self-signed certificate, but I don't know how this protocol works. I connect two apps with a socket SSL and it works fine. The server is a Python app and the client is an Android app. I ...
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315 views

PKI certificate validation graphs, trees and cross signing

I am just trying to get the basics of PKI and TLS and understand how it works. I came across Mozillas post about pkix where they mention that the new library allows graph processing and hence it ...
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1answer
1k views

How do I securely deal with SSL certificate validation failure when the client date is incorrect?

I have an application that runs in mobile devices and connects to my server via HTTPS. At times the connection fail because the device has a date set in the past (before the 'valid from' date on my ...
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1answer
2k views

Is Google Chrome Extension access to SSL certificate validation output possible?

I want to develop an extension which will stop an user from proceeding to any banking site (configurable by user) if a proxy like paros is seating in between sending fake certificate to user. My ...
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3answers
314 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
231 views

Should every SAML identity provider provide a unique public certificate to the service provider?

When accepting public keys from someone setting up an identity provider for access to resources protected by a service provider using SAML 2.0, do you absolutely need to have a unique certificate? Is ...
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2answers
565 views

Certificate authorities: history and registration

CA's are a key part of the internet's infrastructure few people are aware of. SSL was mostly hacked together at Netscape in 1995. I'd like to understand more about the organizational structure of CA's ...
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254 views

What do people mean by “top-down manner” in X.509 certificates?

What do people mean by saying that X.509 certificates work in "top-down manner"? Do they say that because CAs can do cross certifications?
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224 views

Does Internet Explorer handle Extended Validation properly

I'm reading about Extended Validation (EV) certificates and have a few questions. From what I understand, EV allows domain owners to pay extra for a especially trusted certificate (that the browser ...
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391 views

Choosing the right X.509 certificate infrastructure for securing LAN communications between a PC and a device

Edit: seems like I was quite hasty when typing in my question at first, so here is an updated version of it. I am developing an application that runs on PCs which are on the same LAN as other ...
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1answer
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Windows' default certificate store for intermediate vs trusted root certificates - my self signed root CA cert goes to 'intermediate' by default?

Is it possible to create self-signed root CA certificate that Windows will import to Trusted Root by default instead of Intemediate certificate store ? Obviously, it won't do it without the big giant ...
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3answers
587 views

Are intermediate signing certs the only secure+practical way to manage OpenVPN client certs?

My organization needs to issue (and revoke) OpenVPN client certificates for people working remotely. Our system is based on a standard OpenSSL CA setup and the easy-rsa tools, and the whole directory ...
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3answers
2k views

Key Exchange using PKI

I'm new to the field of cryptography and trying out a sample program to understand PKI key exchange mechanism. I tried creating a self signed certificate using openssl openssl req -x509 -nodes ...
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1answer
139 views

Which .CER file format is more secure for purposes of an AIA record?

What file format is most appropriate or secure for the AIA record in a PKI certificate? The options I'm aware of are: DER encoded binary X.509 (.cer) Base-64 encoded X.509 (.cer) I also have the ...
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207 views

IKEv2 in remote access scenarios

Can someone explain why, in remote access scenarios, IKEv2 EAP password-based user auth combined with IKEv2 PUBKEY gateway auth is preferable over mixed IKEv2 PSK/PUBKEY auth using the same password ...
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104 views

Does it make sense that OCSP returns state for the signer CA itself

I have seen an implementation that in signature verification time searches for OCSP responses signed by the CA validating the status of the CA itself, so my question is if somewhere (maybe RFC2560) ...
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5k views

Clearing IE temp files don't erase CRL history. How can this be purged?

Even after I purge all my Internet temporary files, I still see information when I type certutil -urlcache How do I purge this information?
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How to generate self-signed certificate for S/MIME with usage 'signing' only, like DOD uses

I'm testing a feature to support S/MIME mail signing and encryption. As far as I know US DOD has quite strict standard on these certificates. So that DoD uses separate authentication, signing, and ...
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1answer
892 views

question about implicitly tags in ASN.1

From the X.509 RFC, in the "Implicitly Tagged Module" section: CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint DistributionPoint ::= SEQUENCE { distributionPoint [0] ...
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2answers
178 views

How can I force certain the webclient to honor or remember certain parameters from the webserver?

HTTPS is subject to several MITM attacks, that is clear. However I think it would be helpful to the ITSec crowd if there was a way to force a certain browser behaviour when accessing known-trusted ...
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2answers
123 views

Self-signed cert - how it works

I am new to SSL / digital certificates / signatures. What I know is that a digital signature must be verified/decrypted using the public key. So a cert that is signed by a CA must be ...
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113 views

When can I commit an OpenSSL Certificate (.pem) to source control?

That is to say, in what cases does it make sense to commit .cer files, or a stack of .cer files in a .pem, to internal source control like SVN or Git? If it's just a list of signed public keys, I ...
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SSL Client Authentication Failure

I have a setup where the client wants to make https call to the server. The client has a certificate installed on the machine The trust chain of the cert: Root CA      ...
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Managing/Deploying a code signature certificate - Java Applet

I wonder how to manage/deploy a code signature certificate used by the JVM in a corporate context. Suppose you signed a Java applet (executed in browser by corporate users), how do you deal with the ...
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161 views

Why not use same certificate for webserver TLS and Signing in SAML?

I have read a bit about configuring shibboleth, and recommendations for SAML at internet2 I get the point that a certificate does not have to be signed when used for SAML, because actually only the ...