0
votes
2answers
41 views

ECDSA ciphers and forward secrecy question about key exchange

I have heard that with forward secrecy that the ECDSA ciphers generate different keys for "each session" because they are not dependent on the private key of the server. My question is how is "each ...
0
votes
2answers
71 views

What would cause a server to only send over 1 SSL certificate to a client?

We have a secure server that seems to only be sending over the identity certificate. Running the hostname through Qualys says that only 1 cert was provided. The intermediate had to be downloaded on ...
1
vote
1answer
34 views

ECDSA/RSA certifcates and cipher selection

In this image can someone tell me if a standard RSA certificate can support the EC*_RSA ciphers listed? If so do you create the typical RSA keys when you are creating the CSR? Also I am fairly ...
0
votes
1answer
64 views

What is the deal with Valicert SSL root certificates?

Does anyone know what the status of the "Valicert Class 2 Validation Authority" root certificate is or what's going on with Valicert in general? I've heard that that cert has been deprecated, no ...
2
votes
4answers
129 views

SSL root certificate optional?

I may have been under the wrong impression on how servers should be setup and what certificates actually get sent over during the server hello certificate message. I came across this today from ...
-1
votes
1answer
37 views

Can a CSR be created in OpenSSL with SHA2?

Can a CSR be created in OpenSSL with SHA2? If so, what would the command be and what does this tell the CA, if anything? If you could create a CSR using SHA2 would it "tell" the signing CA to use it ...
0
votes
1answer
131 views

4096 bit RSA encryption keys vs 2048

Where do 4096 bit RSA keys for SSL certs currently stand in terms of things like CA support, browser support, etc? In the overall scheme of things is the increased security worth the risk of 4096 bit ...
0
votes
2answers
59 views

Typical mistakes when implementing digital signatures?

I am looking for a list of typical mistakes someone can make when implementing digital signatures for a software. And of course why they are mistakes and how an attacker could take advantage of them. ...
1
vote
1answer
55 views

Self-signing client certificates and distributing them, is the following a sound procedure?

I have a case at hand as follows: There is a number of clients in Internet (i.e. untrusted channel), initially in hundreds but growing in numbers. There is a server doing processing related to these ...
1
vote
1answer
73 views

CSR from IIS 8 and Keeping my Private Key a Secret

I've been trying to understand something. When you generate a CSR from IIS, how is the private key kept as a secret, or is it? Do CA's email you a certificate that includes your private key? Because ...
1
vote
1answer
51 views

How to safely renew user and CA certificates in a PKI

I am currently developing my own PKI where x.509-client-certificates are issued by a public server. At the moment, the CA-public key is distributed with the binary and there are no routines for ...
2
votes
1answer
59 views

Is there any mechanism to audit which signed certificates are unrevoked?

We are currently using EasyRSA and OpenSSL to manage our user VPN certificates for OpenVPN. The process we have in place currently is: User generates a CSR on their laptop and sends it to us to sign ...
2
votes
2answers
61 views

Client Authentication Certificate Not Expiring, but “parent” cert IS

So I have a client-authencation cert installed on client PCs, which doesn't expire for 5 more years. Unfortunately, the cert on our gateway which is used to validate the client cert, expires this ...
2
votes
1answer
64 views

What should a client verify after getting a client certificate?

I have a client that generates a csr, sends it to a server, the server then sign it and return the certificate as a String. the String is then decoded to a x509Certificate (using Bouncycastle's ...
0
votes
2answers
37 views

determine X.509 certificate class

I am very familiar with OpenPGP but don't even use X.509 / S/MIME. I know that there are several classes for certificates (from email check to personal ID check). I would like to know how you ...
0
votes
2answers
41 views

How to encode a username in PKIX certificate?

I was reading through RFC 5280, PKIX Certificate and CRL Profile, Section 4.2.1.6, Subject Alternative Name: The subject alternative name extension allows identities to be bound to the subject ...
1
vote
1answer
44 views

Are “Certificate Templates” used only as a “Template” or do they validate a certificate request?

I'm trying to learn how Microsoft Certificate Templates interact with a certificate request, and can only guess that they take on one of the two/three forms: They simply help the client create a ...
2
votes
1answer
84 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 ...
4
votes
3answers
155 views

From a trust perspective, is renewing a CA certificate the same as trusting a sub-CA?

I'm trying to understand the validation logic that would occur in the following hypothetical scenario An unpatched XP user who trusts a list of root CAs. Those CAs in particular have been renewed ...
0
votes
1answer
143 views

x509 serial number - hex or decimal

When I run the openssl command openssl x509 -noout -text -in certname on different certs, on some I get a serial number which looks like this. Serial Number: 256 (0x100) On others, I get one ...
1
vote
0answers
33 views

1.3.6.1.5.5.7.1.12 Logotype extension - how can it be generated from openssl command line

If you look at this subCA Certificate from Verisign http://www.tbs-certificats.com/FAQ/en/495.html?p=en/495.html It has the following field 1.3.6.1.5.5.7.1.12: ...
0
votes
0answers
46 views

Openssl command line: How to get “Policy: X509v3 Any Policy” in a certificate I am generating through openssl

I am trying to generate a certificate through openssl which has the following line X509v3 Certificate Policies: Policy: X509v3 Any Policy But I end up getting X509v3 Certificate Policies: ...
1
vote
2answers
62 views

Public e-mail Encryption Certificate

I'm quite new to this, so don't be too hard on me. I'm currently using the CipherMail MTA to generate e-mail encryption certificates. I created an own CA and public and private keys for our contact ...
2
votes
3answers
58 views

Are Extended Validation certificates any more secure than regular ones?

Or are they just an attempt to get you to pay more money to a CA because it tells your browser to show the address bar in green with your organization's name? Also, what are the technical details ...
0
votes
1answer
36 views

Is it possible to create a SMIME only PKI that *can't* be used for SSL?

Assume I have a Root CA that I want to share with hostile untrusted 3rd parties. Then constrain this root using specific EKUs at the root. OID=1.3.6.1.5.5.7.3.4 ; Secure Email Next, ...
1
vote
2answers
64 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 ...
1
vote
1answer
39 views

Resign root CA as SUB?

Imagine I have a Microsoft root offline ca running since half year, but suddenly I want to include it in my company hierarchy, resigning it with the company official root, But I need both continue ...
1
vote
1answer
60 views

Certificate pinning in a browser

I am trying to understand certificate pinning. Google started adding a whitelist of CA certs that they use for their certificates and if a cert for a google service is issued outside of this list ...
2
votes
3answers
80 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 ...
2
votes
2answers
98 views

Certificate authority structure - best practices

I'm working for a company that sells software products to customers some of which do not have the resources and/or know-how to build and maintain their own CA (used for the SSL communication of our ...
5
votes
1answer
625 views

What's keeping a malicious man in the middle server from forging a valid certificate

According to process of authenticating a server certificate: What's keeping a malicious server to fill up a valid server certificate since it knows all the things: Forged Server public key (man ...
0
votes
1answer
110 views

Security weaknesses in using RSA encrypted MD5 hash of certificate content

Suppose you have an Internet banking site based on a secure web server running the HTTPS protocol via port 443. The server authenticates itself to clients through an X.509 certificate signed by a ...
3
votes
2answers
88 views

What are Implicit and Explicit Certificates in Public Key Cryptography?

A Public key is certified by a Trusted Certifying authority, to ensure the integrity of the key and authenticity of the entity who claims to have the corresponding private key. In this Public Key ...
2
votes
2answers
179 views

What happens if the CA has knowledge of private keys?

In a classic PKI scenario, the certificate authority receives signing requests generated by an end-user which owns the keychain, and thus has his private key secret. Consider a scenario in which the ...
1
vote
1answer
45 views

When does S/MIME require the other party's certificate and when is their key enough?

Trying to understand S/MIME implementation, I see that sometimes you must have the other party's certificate, and sometimes its enough to just have their public key. I'm confused as to when you need ...
0
votes
1answer
63 views

list of PKCS7 certificate file extensions

RSA (the company) devises and publishes the public key cryptography standards. In those standards PKCS #7 is a standard which defines how to encrypt and sign messages using PKI. PKCS#7 defines a ...
1
vote
2answers
98 views

Where to find or purchase non-SSL certificates

I hope this is the right stackexchange - if not, please advise. As to the actual question: have a system we've developed that makes heavy use of asymmetric cryptography in various different ways ...
0
votes
1answer
143 views

Trusted Certificate Authorities - how do they work?

microsoft.com for example can use a Verisign Certificate for their domain. What are the chances that an attacker could ask verisign for a m1crosoft.com domain and get approved? It is very simillar, ...
3
votes
1answer
95 views

Public keys without the certificates

There are two clients and a server. Each client generates an RSA key pair and uploads public key to the server. The server associates the public key with the user identifier that is specified during ...
1
vote
1answer
100 views

Is there any way to restrict multiple access to my server at the same time using one client certificate?

My Server is Windows 2008. Mr. X is accessing my web server using Mr. X's certificate. In that time, an outsider is also trying to access my server using Mr. X's certificate (somehow he got it). Is ...
1
vote
1answer
40 views

In a 3 tier (or more) PKI, is it permissible that a Name Constraint only be defined on the middle tier?

I'm working with an Issuing CA that doesn't support name constraints that are defined at a higher level. Assuming that it issues certificates that are compliant with the Name Constraints that are ...
3
votes
1answer
146 views

Internal code-signing certificate on Windows

I'm looking to improve defense-in-depth on a system, primarily by closing some holes in injected DLLs. Certain applications installed on the system cause helper DLLs (e.g. shell extensions, BHOs, ...
6
votes
5answers
280 views

Why are private certificates not trusted?

When we go to websites that have generated certificates themselves you see this red screen that says do not go there!: However when it is trusted by some companies it's all good. So I have a couple ...
1
vote
3answers
146 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 ...
5
votes
3answers
552 views

Does checking the fingerprint of a self signed certificate improve security?

I am currently developing a component for an application that does TCP communication with a device inside a local area network. I use TLS to provide data encryption, integration and authorisation. ...
2
votes
1answer
222 views

How can a trusted intranet certificate be issued if they are being phased out?

I've just seen this article regarding the phasing out of intranet names on SSL certificates. However, CAs such as this one claim to still issue them and it will be "Trusted by all popular browsers" ...
1
vote
4answers
154 views

search CA for someone's public key

do CAs offer service wherein an application can request someone's public key? i am trying to do this but i am unsure if it is correct (suggestions of better ways to do it will be most appreciated): ...
4
votes
1answer
396 views

Who is this strangely named Certificate Authority?

I'm researching certificate authorities, and I just have no idea what to think of the CA named x00Ax00-x00Tx00rx00ux00sx00tx00 x00Gx00ex00sx00.x00 x00fx00xFCx00rx00 ...
2
votes
1answer
102 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?
2
votes
1answer
2k views

Why is a CA certificate required for EAP-TLS clients?

When setting up clients with WPA2 EAP-TLS, most clients (ie: my phone, my computer) require both a client public/private keypair (for obvious reasons) and a certificate authority certificate. It's ...