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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Can IE be made to imitate the behavior of Chrome's KeyGen element?

Is there any way I can repurpose existing ActiveX controls or functionality to get IE to work with the KeyGen element? Assistance getting Safari to work with this optional HTML5 spec would be ...
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3answers
3k views

Do client certificates provide protection against MITM?

I'm looking for a way to protect clients from a MITM attack without using a VPN, and ToR. My thought is that client certificates might do the job, but I'm not entirely sure since not too much server ...
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2answers
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Self-signed certificates usage for code signing purposes

if a self-signed certificate is trusted by the client's certificate store, then it should be fine to be used, since the client trusts the issuer of the certificate as it does any other trusted CA ...
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2answers
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Chrome SSL Warning: “You cannot proceed because the website operator has requested heightened security for this domain. ”

I'm trying to go to the URL below, and Chrome warns me that the wildcard certificate is not valid for this domain. ...
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4answers
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how to import a private key in windows

Say I have an X.509 cert and a private key that corresponds to it. I can import X.509 certs easily enough into Windows but what about private keys? Is the only way I can do that by converting both ...
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3answers
427 views

Forged SSL without installation of root CA, possible?

Consider visiting a secure website like Gmail. Is it possible to forge the website certificate only by having full control over the internet provider? I mean is it practically possible for a provider ...
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1answer
1k views

X.509 certificate attack (small sha1 private key)

I've got a X.509 certificate, created by an unknown CA. The only thing I know is that the private key is very short, so I can retrive the private key. Is there any program I can use? The used ...
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1answer
385 views

How can I use certificates to secure my webservices? What is available to javascript?

I have a few web services that are accessed over public wifi connections and I think it would be a good idea to issue certificates to encrypt data, prevent MITM, and invalid impersonation (beyond what ...
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4answers
2k views

Does a renewed certificate open old messages?

I have a digital certificate that I use to exchange messages with peers, my certificate expiration date is due next year, suppose I renew this certificate before it expires, will I be able to open the ...
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1answer
225 views

how does OpenSSL create X.509 certs from SPKACs?

The SPKAC ASN.1 description: PublicKeyAndChallenge ::= SEQUENCE { spki SubjectPublicKeyInfo, challenge IA5STRING } SignedPublicKeyAndChallenge ::= SEQUENCE { publicKeyAndChallenge ...
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2answers
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What did the certificate authority do with my CSR?

I needed to reach a web service which is not mine. The IT department of that web service has asked me to send them a CSR (certificate signing request). Then, he will send me back a signed certificate ...
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3answers
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What issues arise from sharing a SSL certificate's private key?

Scenario: I am hosting a website for a my client, who we'll call S. S owns the domain s.com and I own the servers that actually host the website. S now wants to enable SSL on their website. I have ...
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2answers
3k views

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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3answers
556 views

Server Certificates, certificate authority, and servers

I currently have a valid wildcard certificate installed on OS X 10.8.2 server. To make sure we know what I'm talking about the cert is *.domain.com (example only) I'd love to use this to secure as ...
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7answers
17k views

How do certification authorities store their private root keys?

Knowledge of a CA private key would allow MitM attackers to transparently supplant any certificates signed by that private key. It would also allow cyber criminals to start forging their own trusted ...
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1answer
480 views

signatureAlgorithm vs. tbsCertificate -> signature

From the X.509 RFC: Certificate ::= SEQUENCE { tbsCertificate TBSCertificate, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } TBSCertificate ::= ...
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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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4answers
2k views

Client Certificate in SSL HandShake insecure?

Imagine we have an application which is trying to establish a secure connection to a server by using SSL. Now we want the user to authenticate himself with a client certificate which he stores in an ...
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2answers
24k views

ssltest: Chain issues - Contains anchor

I've run ssltest on web application and it found "Chain issues - Contains anchor" (section "Additional Certificates (if supplied)") What does it mean? Should it be fixed? Can it be exploited?
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1answer
135 views

XER encoded X.509 certs [closed]

Would anyone happen to have an example of an XER encoded X.509 certificate so I can play around with it? Thanks!
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2answers
1k views

How is certificate forgery with cheap CA's prevented?

In order to perform a successful man in the middle attack on HTTPS, one needs to either strip SSL layer and convert it to HTTP completely or needs to have a valid certificate from a CA for the same ...
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3answers
1k views

Public key Infrastructure

Here the MD5 hash is being encrypted with the private key of the sender. But I read in a paper that private key is only used for signing and not encrypting. Is the image wrong or can private key ...
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3answers
667 views

Issuing SSL certificates for device automation software package without domain names

We are developing the automation software for Windows which communicates with the certain devices via our own private connection protocol. That software package consists of several server (including ...
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2answers
186 views

How can a certificate be valid in the Hybrid Model but not in the Chain Model?

All dates in European format! I am learning about validity models, but the solution for this assignment confuses me. Translation: The relevant data for the applicable certificates are shown ...
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3answers
919 views

How do you verify a certificate belongs to a domain?

I'm using PHP and trying to verify a SSL certificate belongs to the SMTP domain/IP I'm connecting to. Currently I can verify the certificate is valid using the following code $resource = fsockopen( ...
9
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1answer
8k views

Which key usages are required by each key exchange method?

I'm only really concerned with RSA keys, so the exchange methods are RSA (generate a key, encrypt it, and send it over) and [EC]DHE_RSA (generate an ephemeral [EC]DH key, sign it, and use it for key ...
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1answer
474 views

When distributing a CRL over HTTP, what is the optimal refresh time? What logic affects this decision?

When distributing a CRL over HTTP, what is the optimal cache and max age settings (etc) for this distribution mechanism? Related information on a different answer Consider using HTTP instead ...
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1answer
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AIA/CRL locations for Offline Root

I've read the answer to the following "Checklist on building an Offline Root & Intermediate Certificate Authority (CA)" and I have one questions based on the system I am trying building It's an ...
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2answers
254 views

Secure cookies and Path Length Constraint

Using apache 2.2.3 on oracle enterprise linux. When setting following setting in httpd.conf: Header edit Set-Cookie ^(.*)$ $1;Secure , cookie generation (which happens on our registration page) ...
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3answers
7k views

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 ...
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2answers
930 views

distribution mechanisms for CRLs

From the X.509 RFC: DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer ...
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2answers
8k views

How to get private key from certificate and base 64 encoded key?

Sorry for the poor question. Suppose I have a certificate of the following lines: -----BEGIN CERTIFICATE----- //22 Lines of encoded junk -----END CERTIFICATE----- And then this base64 encoded ...
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2answers
1k 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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4answers
5k views

What alternatives are there to the existing Certificate Authority system for SSL?

Whilst the current CA system works very well for a lot of people, it does put a lot of power into individual CAs' hands, and makes a CA hack potentially devastating for customers and business. What ...
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2answers
204 views

Certificate security in intranet environment?

We have this topology in our company: A new rule says that each document being sent by Outlook should be encrypted. We decided using PGP. We already have a certificate (self-signed). The problem ...
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0answers
142 views

Why not buy cheap SSL certificates? [duplicate]

Possible Duplicate: Is there any technical security reason not to buy the cheapest SSL certificate you can find? The comparison in Godaddy's website, makes it clear: they're just cheaper ...
5
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1answer
535 views

Which attributes of a X509v3 certificate are never really used?

Are there any extensions/extended key usage attributes of a X.509Certificate that are rarely or never used in practice? Either due to never being part of an issued certificate or because they are ...
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2answers
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Are there really functioning quantum computers?

I saw this video on youtube on quantum computing. It says that a company called dwavesys has already made commercially available quantum computer. I checked on the website and it exists. I thought ...
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5answers
2k views

Why is this certificate valid for so many domains?

If you look at the (invalid) certificate for https://i.imgur.com/ it says only valid for the following names: The certificate is only valid for the following names and then a list of about 100 names. ...
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1answer
2k views

What are the Netscape Cert Type attributes? Why/when are they needed?

What are the Netscape Cert Type attributes in a X.509 Certificate and how are they different with the X509v3 extensions? Example: There is the Client/Server Extended Key Usage (X.509) but there is ...
2
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1answer
822 views

Can Diffie-Hellman Anonymous be used as a cipher for SSL for one-way certifiate-based authentication

I want to use Diffie-Hellman anonymous cipher for SSL. I also want to use a one-way certificate for server authentication. Is this possible?
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4answers
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What is the potential impact of these SSL certificate validation vulnerabilities?

I just finished reading through this paper by Georgiev et al, which demonstrates a wide range of serious security flaws in SSL certificate validation in various non-browser software, libraries and ...
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2answers
190 views

What is the state of the Windows Update certificate after Flame?

May 28, The Flame malware is discovered in Iran and by Kaspersky Labs. June 5, Dan Goodin (Ars Technica) points out that Flame had hijacked WindowsUpdate, spreading signed malware through that ...
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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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2answers
902 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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2answers
2k views

What are the implications of adding a self signed certificate to the Windows Trusted Root Certification Authorities store?

I'm a budding website developer, so please bear with my ignorance. Say I had to encrypt my website with HTTPS and I got sick of having to click "Continue" every time a warning came up about an ...
2
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1answer
131 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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1answer
168 views

What keys are involved in an X.509 certificate?

I'm trying to examine some instances where an X.509 certificate uses public and private keys for a paper I'm going to write. However, the only thing I have explicitly seen so far is in one of the ...
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2answers
2k views

x.509 CRLs: next update?

An X.509 certificate revocation list contains a field specifying when the next such list is expected to be issued. I'm trying to figure out the importance of this field...I know that sometimes ...
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3answers
1k views

Digital Signature and Verification?

AFAIK , When Alice wants to write a message to Bob -- she uses Bob's public key and encrypt the message - and then Bob - using his private key - use to decrypt it. So public key is used to decrypt ...