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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108 views

Should we trust online banks with our credit card information?

I'm thinking of buying a product for someone using the steam platform. Being in Germany, the best (least expensive) option would be to use a local bank. Logging in, choosing a product and checking out ...
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1answer
1k views

OpenSSL check if a SSL certificate is SHA-1 or SHA256 signed

How do I check if an OpenSSL certificate issued to a site is SHA-1 or SHA-256? I have a quite a lot of intranet sites using OpenSSL certificates and I am a bit confused as when I check the certificate ...
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2answers
61 views

How does Certificate Transparance detect fake or forked logs?

I am trying to understand Certificate Transparency. Let's say I want to snoop on somebody's email. So I go hack or bribe a CA, have them issue a certificate for google.com, and then I present it when ...
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1answer
130 views

Attribute Certificates and Access Management

I recently came across Attribute Certificates (RFC 5755), which can be used as a means for authorisation. I like the idea but I have spent a lot of time searching for information how this works in a ...
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1answer
367 views

EC private key, RSA certificate. Is this realisable?

I was wondering if is it possible to generate EC private key: openssl ecparam -name sect571r1 -out ecparam.pem openssl ecparam -in ecparam.pem -genkey -noout -out eckey.pem then generate ...
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3answers
338 views

HTTPS client certificates for server-to-server

Say you have two servers with certificates proving their domains (e.g. for use with HTTPS). Can one of these servers use their certificate as a client certificate when talking to the other, so that ...
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1answer
299 views

A certificate site name mismatch when using preinstalled Toshiba software? (Superfish?)

On my Toshiba laptop there are a variety of different Toshiba programs that came pre-installed. Many of them are some sort of utility, optimizer, checkup, and update kind of programs that I guess are ...
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2answers
301 views

Does Ephemeral Diffie-Hellman require a certificate?

In Ephemeral Diffie-Hellman, the key pair is generated every time. In practice, does this mean I never need a certificate? Or that means I need a new cert every single time?
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535 views

How to make a decent Certificate Signing Request (CSR)?

I'd like to know how to make a decent Certificate Signing Request (CSR) to secure my website and e-mail with a wildcard SSL certificate. With recent exploits as POODLE on SSLv3 and such, I'd like to ...
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1answer
162 views

What does verified file in windows mean? And does it guarantee related files?

Often when I run a .exe file in Windows, a small box pops up that shows that file is from a verified publisher (e.g Microsoft) or in other case, unknown publisher. I know public key encryption can ...
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2answers
161 views

Authentication through digital certificates plus signature

While studying X.509 certificates, I've found that authentication is safer if I associate/combine one or more certificates with each signed message (certificate + signed message). The receiver of ...
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3answers
142 views

How are public key certificates updated securely?

Let's say I get a new computer that's never been connected to the internet before. The first time I connect it to the internet, is it susceptible to a mitm attack while downloading its public key ...
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1answer
200 views

Why does facebook php sdk (and multiple others clients) include CA bundle with a lot of CAs?

This is what facebook ships with their API php client: https://github.com/facebook/facebook-php-sdk-v4/blob/master/src/Facebook/fb_ca_chain_bundle.crt It contains dozens (hundreds?) Root CAs. But ...
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1answer
117 views

How does checking CRLs make sites less safe?

With the frantic certificate upheaval resulting from the Heartbleed fiasco [drink!], there has been lots of talk regarding certificate revocation, and in particular the policy of certificate ...
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1answer
414 views

How secure is PKCS #12

I need to move user cryptographic identity between several user devices. In the operating system I have only one option: use password-protected PKCS #12 to import the identity to the OS secure store. ...
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1answer
217 views

SSL certificate to protect spoofing of API server

I have a program written in Python that checks the validity of its license key with a remote server. Am I right that an SSL certificate would make it possible to prevent spoofing (host redirects for ...
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1answer
3k views

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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1answer
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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2answers
703 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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1answer
523 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 self-...
2
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1answer
239 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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2answers
714 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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2answers
6k views

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 iPad ...
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2answers
784 views

How do I verify, parse and process the results of the HTML5 keygen tag?

I'm investigating the HTML5 attribute Keygen and discovered that it sends this data on a Form POST to the server. Here is an example POST: ...
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2answers
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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1answer
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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2answers
2k views

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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1answer
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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2answers
42 views

CA Certificate Lifecycle

I'm planning to implement a new PKI with 2 tiers of CAs. I'll have end entity certificates with a lifetime of up to 5 years. This means my Issuing CA should be valid for 10 years, in order to be able ...
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1answer
57 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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1answer
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 ...
2
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1answer
78 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] ...
2
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1answer
135 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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1answer
604 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: ...
2
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1answer
814 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 ...
2
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1answer
307 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 ...
2
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1answer
770 views

Determine private key size using public certificate [duplicate]

I have a public certificate in a PEM (.pem) file -----BEGIN CERTIFICATE----- MIICsjCCAZqgAwIBAgIJAMA1YIQ2JLXDMA0GCSqGSIb3DQEBBQUAMBExDzANBgNV ... 29V/R9RZOoSBHDzGPL84wm4qojMuwQ== -----...
2
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1answer
154 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 stapling)...
2
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1answer
68 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. ...
2
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1answer
216 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 ...
2
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1answer
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 ...
2
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1answer
588 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 ...
2
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1answer
437 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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2answers
2k views

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 ...
2
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2answers
324 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 ...
2
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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
322 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
241 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
574 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 ...
2
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1answer
256 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?