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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6
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2answers
782 views

Can I use my old SSL certificate with websites in subfolders?

We have a single domain SSL for a website that looks like this: www.website.company.com We are going to expand and do following: www.website.company.com www.website.company.com/dk ...
3
votes
2answers
144 views

Use openssl to individually verify components of a certificate chain

This is related to another question, How to verify a signature of one entity by another using OpenSSL CLI? I used openssl s_client -showcerts -connect www.google.com:443 to collect three certificates ...
3
votes
3answers
192 views

How to check if I have a rogue SSL/TLS certificate?

It's known, that if someone manages to install their certificate as a trusted certificate on your Windows computer, they can read all you SSl/TLS traffic with man-in-the-middle attack and you won't ...
1
vote
1answer
16 views

Conditions for reusing client certs in TLSv1

In my setup I am using client certs, and the client devices are iPhones running iOS 9.0. In comparing some network traces I noticed that in some cases, the server asks for the client certificate for ...
2
votes
1answer
49 views

Will browsers trust an expired self sign certificate in the Trusted Root store

I recently discovered that if Windows AD LDS services are bound to a self signed certificate, that processes will continue to trust the cert even if it's expired. My guess is this is because the cert ...
0
votes
1answer
73 views

Are Free SSL/TLS Certificates Trustworthy ? Can Cert Providers Snoop On Traffic? [duplicate]

I know nothing about encryption, SSL, TLS, certificates and have come across several companies offering free SSL/TLS certificates. How trustworthy are these offers? Why would I want to adopt this ...
-2
votes
1answer
145 views

Are VPNs for iPhones vulnerable to hacking?

I use VPNs all the time on my iPhone to get around websites being blocked and sometimes just for privacy, but are they secure? In this video the guy installed a certificate on the lady's phone that ...
3
votes
1answer
43 views

SSL negotiating too low a protocol?

I'm trying to diagnose a potential SSL/TLS problem between a Mac client and a Windows server. I have generated my own root cert and signed a cert for the server, and installed the root cert on the ...
2
votes
3answers
110 views

Why doesn't openssl s_client correctly validate google.com:443?

I try $ openssl s_client -connect www.google.com:443 but it openssl complains that the cert chain is invalid: $ openssl s_client -connect www.google.com:443 CONNECTED(00000003) depth=2 C = US, O = ...
28
votes
3answers
2k views

Does any technology prevent a CA unilaterally revoking a certificate?

As far as I can tell, a CA is in a position to unilaterally revoke a certificate via the standard mechanisms (CRL, OCSP). In an increasingly TLS world, what current technology stops a CA shutting ...
3
votes
1answer
72 views

How to verify a signature of one entity by another using OpenSSL CLI?

I'm teaching a class about certificate chains, so I download the chain from www.google.com which has 4 certs. I want to demonstrate how the dependencies work from issuer to subject by showing that ...
5
votes
5answers
203 views

VPN with client certificate via managed PKI - where did private key come from?

$company allows Mac users to request a client certificate via Symantec PKI to connect to their SSL VPN server. This process involves going to a specific Symantec website (has some sort of ID to ...
1
vote
1answer
91 views

MITMproxy doesn't display HTTP/HTTPS traffic of Android Apps

I am using mitmproxy to analyse the https traffic of some Android Apps. A few days ago I was able to intercept all the traffic without any problem and now mitmproxy doesn't seem to work properly. ...
0
votes
1answer
54 views

Verifying that a request is internal

I've got a web app that will only output safe code. It needs to pass this to a Python backend. The logical way to pass things between JavaScript and Python is to have a Flask server running. Then, the ...
11
votes
2answers
816 views

How long can X.509 certificate chains be?

Usually, I only see certificate chains with a root CA, an intermediate one, and a third one for the particular SSL/TLS website; but can X.509 certificate chains be deeper than 3 levels? Is there a ...
4
votes
5answers
240 views

How does Blucoat Proxy allow governments to decrypt SSL?

I am asking about systems like: Bluecoat ProxySG I saw some relevant answers here: Can my company see what HTTPS sites I went to? It explains how employers can do it using root certificates, but ...
4
votes
2answers
97 views

Does SSL certification have anything to do with the website legitamacy?

Does SSL certification have anything to do with the website's legitimacy? Are those websites which has it are under some kinda monitoring? Generally speaking, can a company say they follow the law ...
1
vote
0answers
51 views

What Key Usage values are required to support Code Signing?

I have a .pfx that I want to use to sign a Clickonce app. However, on trying to do so, Visual Studio gives me "The selected certificate is not valid for code signing." When I go to certmgr.msc and ...
3
votes
2answers
117 views

Can a CN-only certificate bypass a name constraint if the CA goes rogue?

I am trying to cross-certify an internal issuer certificate, adding a name constraint for our domain. However, it seems that an attacker could bypass this protection by putting the desired host name ...
1
vote
0answers
90 views

MQTT (Mosquitto) certificate SSL23_GET_CLIENT_HELLO:unknown protocol [closed]

I'm been desperately trying to get my MQTT clients to connect to my MQTT broker which is set up with a certificate from a CA. To be able to get the CA certificate, I've used the letsencrypt python ...
1
vote
2answers
94 views

Single Domain SSL Certificate vs Wildcard Certificate

Probably a rather odd question, but something that came to mind. Wildcard certificates are about 10 times more expensive than a single certificate. However with a single certificate, you can secure ...
3
votes
1answer
74 views

How to force browser to ask user to resubmit certificate after a logout

We have a website which supports form based authentication (i.e. username and password based) and certificate authentication where a user submits his or her certificate, the username is extracted from ...
0
votes
3answers
113 views

What implications does the KeRanger infection have for Mac OSX security?

Recently some hackers replaced installers for a popular torrent client with an infected version. According to paloaltonetworks, they have no idea how the hackers managed to do this (let's just assume ...
0
votes
2answers
85 views

How In-House Certificate Authority works (e.g. EJBCA)

I have a simple (dumb?) question with respect to EJBCA. I have been exploring how In-house CAs work and issue certificates. However, I am not able to understand who will be trusted on the top level in ...
5
votes
2answers
145 views

Why is weakness of SHA-1 considered a threat to TLS security

If I understand correctly the role that a hashing algorithm (e.g. SHA-1) plays in TLS certificates is as follows: The hashing function is applied to a subject's public key. The CA then uses their ...
1
vote
1answer
60 views

ECDSA implicit certificate using OpenSSL

I am trying to generate implicit ECDSA certificate only for signing and verification using OpenSSL. I tried google but I am getting many research papers. I understood that A messages need to be signed ...
1
vote
2answers
36 views

Client verification with PKCS#7

When a client sends you a pkcs#7 file to communicate with you, Is this because the file has their public key(certificate) and their chain and to avoid the confusion on your side what needs to be there ...
0
votes
1answer
79 views

CSR with only public key with openssl

So I have been doing my research and haven't found anything specific enough to my problem. As the question title states, I want to make a CSR with only the public key. What I have been able to do is ...
0
votes
1answer
51 views

What is the difference between a certificate, a signature and a thumbprint in case of windows exe/binaries?

I am trying to understand the difference between signature , thumbprint and certificate in context of windows executable and binaries. I looked up on internet before posting this question but I did ...
1
vote
2answers
67 views

Reissuing certificates with SHA-2

I recently setup my own CA, and imported the CA cert into devices across the company. I then deployed certificates to our various servers, etc.. All using SHA-1 signatures (the default in the tool I ...
3
votes
1answer
116 views

Understanding how does certificate validation work

I'm using Wireshark for better understanding how is a SSL connection established. I captured the traffic of visiting three pages: reddit, facebook and this one. All HTTPS of course. Reddit: after the ...
1
vote
1answer
63 views

TinyCA missing CRL information in root and leaf certificates

I setup a new CA using TinyCA. When creating the CA i used an internal host name for the crl url exactly as follows: http://myserver.com/crl.pem And I have exported the CRL to that location, and I ...
2
votes
0answers
24 views

Finding the EMSA-PKCS1-v1_5 DigestAlgorithm field in the x509 certificate

From the RFC - https://www.ietf.org/rfc/rfc3447.txt A.2.4 RSASSA-PKCS1-v1_5 For each OID, the parameters field associated with this OID in a value of type AlgorithmIdentifier shall have a value ...
0
votes
2answers
54 views

Using client certs issued by a third party CA

I have a site that is protected with a user name/password login. For users that want to enter a certain area of the site, there is (legacy) code that looks for a client certificate and if the email in ...
7
votes
2answers
524 views

Will Google block HMAC-SHA1 along with SHA1 signed certificates?

So, right now, there is a push for moving from SHA1 signed certificates to SHA256 signed certificates by Google. My understanding is that you cannot use SHA1 for signing certificates but HMAC-SHA1 can ...
1
vote
2answers
44 views

Using mutual authentication, should I still worry about message integrity and replay attack?

I'm trying to secure a REST API, our situation is that every client connecting to this API will also have a certificate signed by our own CA. Because of this, I think we can use the client certificate ...
1
vote
0answers
34 views

How Do I Create a Production Client Authentication Certificate for Azure Key Vault?

I am learning about Azure Key Vault, and one of the scenarios it supports is certificate authentication, which you can read about here. The samples do a great job of explaining how to make a ...
81
votes
4answers
11k views

What prevents me from buying a SSL certificate for a domain I don't control?

Can I simply build a webserver, make its hostname "google.com", create a CSR off that server, and send that to a Certificate Authority for signing? Let's say I pick the cheapest and dodgiest outfit I ...
1
vote
1answer
123 views

What does browser do when it queries xxx.example.com and it gets a certificate for yyy.example.com(top level domain is same)?

The question is actually about what level of validations browser does when it gets certificates of some other domains like case 1: Accessing abc.google.com and got def.google.com case 2: Accessing ...
3
votes
1answer
153 views

Is It OK If a Server Does Not Verify a Certificate?

I am currently learning a LOT about Azure, Azure Active Directory, and Azure Key Vault (AKV). To start with, please see this article: In particular, I am interested in this statement: When ...
3
votes
2answers
88 views

When should I renew certification authority?

What is best practice in renewing certification authorities? I mean when should I renew certification authority? For example, suppose I have the following setup: 1. Root CA with validity of 30 years ...
0
votes
0answers
31 views

How do the eduroam WPA-Enterprise 802.1X certificates look like?

As outlined in another answer, the official eduroam WiFi profiles available from https://cat.eduroam.org/ (verified for uWaterloo and uOttawa), as well as sample official instructions of the ...
1
vote
1answer
58 views

Can Passpoint X.509 certificates be used to MITM SSL connections on Passpoint networks?

Passpoint/Hotspot 2.0 public networks like LinkNYC require users to install X.509 certificates, for EAP authentication. Can these certificates be used by the provider to execute man-in-the middle ...
0
votes
1answer
71 views

Safari not showing GREEN lettering for EV SSL

I've recently installed an EV SSL cert on my server, Chrome and Firefox show a green banner and padlock denoting the EV cert is installed, but in Safari, it just shows a gray padlock... is there ...
1
vote
2answers
110 views

Why did I get a wrong IP and certificate for www.facebook.com just now? [closed]

I just navigated to www.facebook.com and my browser alerted me that an invalid certificate has been received. I checked the cert in question, and I was surprised to see that the Common Name on it was ...
2
votes
1answer
79 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 ...
1
vote
1answer
115 views

What can a trusted certificate do?

I am doing some reading about security on mobile applications because I found an article about Man in the Middle Attacks. I saw in that article and in many other places (including ...
-1
votes
1answer
48 views

HTTPS - if this protocol protect against connecting to false server?

I know about SSL certificates. However it is ok to say: protocol HTTPS protects against connecting to false server ?
1
vote
1answer
18 views

Certificate Setup Over Many Remote Resources

Imagine that you have a web app that needs to talk to a central api server with its purchased certificate. This server provides a token to the web app to be used to authenticate and talk to another ...
2
votes
2answers
94 views

Why do we need certificates confirming certificates?

Why do we need certificates confirming certificates? Why create a hierarchy or tree? These questions makes me confused, could you explain it me?