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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1answer
7k views

What damage could be done if a malicious certificate had an identical “Subject Key Identifier”?

I'm looking at the the Subject Key Identifier attribute of a CA certificate and am trying to understand the role it plays in validation and infer how validating client software could get it wrong. ...
3
votes
1answer
182 views

Is it a good idea to generate certificate-specific CRLs? What is this technique called?

Suppose I create 3 certificates with the following CRLs Cert1 http://crl.server.com/batch1/root1.crl Cert2 http://crl.server.com/batch2/root2.crl Cert3 ...
3
votes
1answer
2k views

What should a CRL file name look like when “new” and “delta” CRLs are generated?

I suspect my Windows 20012 Certificate Server CRL revocation configuration is incorrect every time I generate a new CRL or a new Delta, only a maximum of 3 files are generated. When I created the ...
2
votes
1answer
3k views

What Enhanced Key Usages are required for PKI infrastructure tasks? (OIDs for OSPF and CRL signing, etc)

I'm building a constrained PKI that specifies EKUs for the the entire hierarchy and want to document the OIDs required for PKI tree maintenance tasks. I understand that clients may not validate the ...
4
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2answers
5k views

Extensions for SSL server certificate

I have some question about the X.509 v3 extensions. What extensions should appear in a proper certificate for a SSL server ?
5
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2answers
4k views

Is an AIA or CRL useful / required at the Root CA if that Root is used to cross certify another PKI?

Suppose I have several independent PKIs that are used Two internal PKIs: One with SHA1 support the other with Suite B algorithms. A partner who I trust and have a policy map with. Since both my ...
3
votes
1answer
745 views

What happens to a certificate's Basic Constraints when a policy map is used?

One feature of a Basic Constraint when applied to a certificate (CA or end certificate) is that I can specify the maximum number of CAs that are permitted in the chain. I'm planning on having a 2 ...
5
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1answer
2k views

What OID Issuance Policies are appropriate for SmartCard and Browser Certificates?

I'm investigating issuance policies for SMIME and Browser certificates with different levels of assurance. For the purposes of S/MIME and Browser certificates, should I even use an assurance policy? ...
25
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3answers
1k views

A Different Approach to PKI

After yet another failure of the public key infrastructure, I was thinking about how broken the whole thing is. This business of undeniably associating an identity with a public key, and all the work ...
4
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2answers
833 views

Does Authenticode still work offline and with a “fake” certificate

Here's our story: We're developing some software (written in C#/.NET) and we're already signing the assemblies with strong names, I do this in Visual Studio with a pfx file that is protected by a ...
4
votes
2answers
502 views

What is the severity of a fake certificate?

I'm not a security specialist, thus reading this Google Blog post about a fake *.google.com certificate, raises a lot of concerns, if anyone can impersonate a website, especially a google website, my ...
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2answers
430 views

How do I import a PKSC#12 private key into Java 5 (which may require PKCS#7)

I have a newer private key I have to import into an older server. How do I take a newer PKCS12 cert and import it into an older version of java that uses a different format?
2
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2answers
1k views

Difference between Encryption and Verification certificate

What is the difference between the Encryption certificate and Verification certificate in Outlook? When exchanging certs, it just requires a digitally-signed message to be sent. It seems as though ...
1
vote
2answers
577 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: ...
9
votes
7answers
294 views

Proving running code on a website is unchanged

Can it be proved to the user that the running code behind a website with security related code is the same as published? I'm currently looking at a few new project ideas and one involves secure ...
0
votes
1answer
185 views

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 ...
2
votes
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 ...
1
vote
2answers
1k views

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 ...
18
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2answers
17k views

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. ...
8
votes
4answers
21k views

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 ...
2
votes
3answers
430 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 ...
0
votes
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 ...
3
votes
1answer
395 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 ...
1
vote
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 ...
2
votes
1answer
231 views

how does OpenSSL create X.509 certs from SPKACs?

The SPKAC ASN.1 description: PublicKeyAndChallenge ::= SEQUENCE { spki SubjectPublicKeyInfo, challenge IA5STRING } SignedPublicKeyAndChallenge ::= SEQUENCE { publicKeyAndChallenge ...
4
votes
2answers
2k views

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 ...
9
votes
3answers
5k views

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 ...
1
vote
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 ...
2
votes
3answers
563 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 ...
165
votes
7answers
18k 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 ...
1
vote
1answer
494 views

signatureAlgorithm vs. tbsCertificate -> signature

From the X.509 RFC: Certificate ::= SEQUENCE { tbsCertificate TBSCertificate, signatureAlgorithm AlgorithmIdentifier, signature BIT STRING } TBSCertificate ::= ...
6
votes
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 ...
3
votes
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 ...
55
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2answers
25k 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?
-1
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1answer
139 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!
8
votes
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 ...
2
votes
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 ...
5
votes
3answers
704 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 ...
5
votes
2answers
187 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 ...
4
votes
3answers
960 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( ...
11
votes
1answer
9k 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 ...
1
vote
1answer
483 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 ...
5
votes
1answer
4k views

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 ...
1
vote
2answers
257 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) ...
5
votes
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 ...
2
votes
2answers
968 views

distribution mechanisms for CRLs

From the X.509 RFC: DistributionPoint ::= SEQUENCE { distributionPoint [0] DistributionPointName OPTIONAL, reasons [1] ReasonFlags OPTIONAL, cRLIssuer ...
1
vote
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 ...
2
votes
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 ...
34
votes
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 ...
1
vote
2answers
208 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 ...