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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19
votes
3answers
2k views

Should I trust a website which uses a HTTPS certificate using SHA-1

I am on a website where I need to pay for something. This website has the following warning in the top left: This site uses a weak security configuration (SHA-1 signatures) so your connection ...
4
votes
1answer
46 views

TLS/SSL Certificate - Key usage and encryption

So I'm looking at google.com's SSL certificate and do not understand a few things: I totally get that it ensures the identity of Google's webserver, but don't understand how it proves anything ...
0
votes
1answer
15 views

Use externally generated CA cert to sign CSR's in OpenSSL

I wondering if it is at all possible to use an externally generated root CA ( and by external I mean an internal root CA that was created using another tool) and use it with OpenSSL to sign a CSR? ...
4
votes
1answer
127 views

Bidirectional encrypted server to server communication using TLS

I have 2 Windows servers and would like to set up encrypted communication between them using TLS. I've been reading up on TLS and X.509 certificates and I think I have a reasonable plan, but would ...
8
votes
2answers
618 views

Did scammers take control of a subdomain to host phishing site?

This morning I received a text message (ostensibly) from my bank: We need to contact you. Please visit https://paymentassistance.nationwide.co.uk for more information My spidey sense immediately ...
-3
votes
0answers
42 views

How do I find out what CA credentials certificates are OK to disable? [on hold]

I need help with figuring what is OK to disable on my certificate's and what does Hong Kong really need to be there for?
1
vote
1answer
34 views

Password manager login with compromised certificates

This morning I booted my work laptop as usual and logged in to Windows, then my password manager (Dashlane, if it makes a difference) as usual. Opening up Chrome and browsing to a site with HTTPS ...
0
votes
1answer
68 views

Securing Internal Mobile REST API

I am planning to create an internal API for mobile devices for a company. They are planning to use this internal mobile app to get data from custom ERP, uploading contract, etc. Thus, it will be ...
2
votes
1answer
52 views

Can a DNS “route” change cause an SSL certificate error?

What I mean by "route change": As a working example, mysite.example.net is set up as: mysite.example.net. 3600 IN CNAME some-other-site.elsewhere.com. ...
1
vote
2answers
90 views

Certificate handling on a small network VPN

Background - I need to set up secure remote access for a small home office. I'm a bit of a noob and haven't needed to handle certificates before. I understand most of the setup but I want to ...
0
votes
2answers
39 views

What is the purpose/role of the “alias” attribute in Java keystore files?

I've heard conflicting information about the purpose of the alias attribute in Java keystore files. Can someone please clarify on what exactly this attribute is, and what it should be set to when ...
0
votes
0answers
18 views

Certificate not showing up for signing in Outlook

I have a new ECA certificate installed on my Windows 7 machine, but when I use Outlook it is not letting me change the signing certificate to the new certificate, but it does let me change the ...
2
votes
2answers
38 views

How do I handle HTTPS certificates for a device with dynamic IP?

I'm fairly new to HTTPS and therefore risk this being a dumb question. I have a server hosted on my Raspberry Pi that allows me to configure it remotely, over a network and I'd like to convert to ...
0
votes
0answers
17 views

How can I use unique PKI from host to client [on hold]

I have hundreds of machines i would like to have unique credentials/certs on. I also have a even more cell phones i need to run diagnostics on the machines. Is there a way i can do this? I will also ...
-1
votes
1answer
24 views

SIM card used with smart card user certificate

Is it possible to put a smart card user certificate (Windows) on a SIM card? (SIM card already has telecom info on it). I'm using Win 2012 and have tried, but I am getting this error "smart card ...
0
votes
0answers
26 views

Validate Code Signing Root Certificate Offline

I am developing a library distributed as a Windows DLL to be called by 3rd party executables. I expect the calling EXE to be digitally signed and need to verify that. I have no control over the ...
6
votes
3answers
261 views

what do you do when an ssl certificate expires and your app uses ssl pinning?

I originally posted this question on StackOverflow, but reposted here due to lack of responses. I am trying to decide if it's a good idea to do ssl pinning in my iOS game that uses a server to ...
8
votes
2answers
10k 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. ...
1
vote
1answer
84 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 ...
1
vote
2answers
96 views

Can I move my private-key to a better token?

I recently purchased a personal signing certificate from GlobalSign - it wasn't cheap either. It arrived yesterday. GlobalSign gave me a "blank" USB security token device - a SafeNet eToken 5100. ...
1
vote
1answer
101 views

Digitally signing a document with your public/private keypair without certificates?

I have generated a private/public key pair using gpg. Can I use this key pair to digitally sign a PDF without a digital certificate, but to still have the signature integrated into the PDF, instead ...
0
votes
0answers
27 views

Web service authorization to specific applications: certificates, embedded secret or both?

My needs are somehow similar to this answer, but I would to be more specific. I have a set of web applications (A and B) that access to a REST service (R). A, B and R could be on the same server or ...
21
votes
4answers
18k views

Provide subjectAltName to openssl directly on command line

Is it possible to provide a subjectAltName-Extension to the openssl req module directly on the command line? I know it's possible via a openssl.cnf file but that's not really elegant for ...
2
votes
1answer
30 views

Can the server detect when a client has disabled certificate pinning?

Many mobile applications enforce certificate pinning in order to make a man-in-the-middle attack difficult to accomplish. However, with a jailbroken/rooted device, it's possible to disable the ...
1
vote
1answer
82 views

Standard for securing web server to client connections via HTTPS on the local area network

I am trying to set up some kind of secure client to web server connection that takes place entirely on local area networks, but I'm having trouble understanding what the recommended best practice is. ...
3
votes
1answer
3k views

Is keystore file (server.jks), my private key file?

My task is to convert .p7b to .pfx. It would be great, if you could provide me some pointers. Below are the steps I used to generate the .p7b file: I generated a .jks (java keystore) file using ...
5
votes
3answers
212 views

How to check if your Android app was updated by MitM?

As I was browsing on my phone yesterday, a gray popup appeared on my screen just as I was swiping up, and I accidentally hit the accept button. In the fraction of a second it was on I was able to read ...
0
votes
0answers
4 views

How to enable IE 10 to accept sha-1 ssl certificate? [migrated]

I have a server certificate issued by a CA that uses sha-1. Chrome (latest) allowed me to access a server that imports the server cert but IE 10 didn't. Is there way that I could configure IE 10 to ...
4
votes
2answers
4k views

Windows Firewall Connection Security with Certificate

I've been fiddling with the Windows firewall configuration of some computers within a VMWare based LAN (no domain). To aid in my testing and debugging, I created a small, self-hosted console ...
1
vote
1answer
32 views

Multi-User-Server Public-Key-Based Authentication

So, lets say we have Alice, John, Peter and Bob. Alice, John and Bob all know Peter's public key and trust Peter. Alice wants to connect to Bob's server, so she presents her public key, which was ...
5
votes
1answer
132 views

Prevent and/or detect installation of root certificates on Windows?

I noticed that some applications installed root certificates on my computer. Is it possible to prevent this? Or is there a firewall or such that notifies me?
4
votes
1answer
53 views

Why is the SHA-1 hash of certificate sent in TLS “Client Certificate URL” extension?

According to RFC6066, constrained clients can send certificate URLs instead of full certificates for TLS client authentication: After negotiation of the use of client certificate URLs has been ...
6
votes
2answers
163 views

Why are certificate chains different in Firefox and Chrome?

I have a server with HTTPS, and I noticed a very strange behavior which I cannot understand. When I checked the chain in Firefox, there is this: But in Chrome I see this: So it's clear, that ...
0
votes
2answers
41 views

What if internal certificate details like CN, Serial Number, validity, CA etc. are shared to external parties from my intranet site?

If by mistake I have shared the details like Common Name, Serial number, etc.. of the certificate of my intranet site/server that is not exposed to the internet will it help attackers exploit the ...
1
vote
1answer
48 views

LetsEncrypt / Exim4 / GnuTLS / cert chaining: “The provided X.509 certificate list is not sorted” error

From what I can determine, you generate a LetsEncrypt certificate that includes the full cert chain thus: # run lets-enc the usual way # then ..: wget -O intermediate.pem ...
18
votes
2answers
891 views

How can I prevent that my users get a certificate issued for my domain on my behalf?

I have a domain, where some other users have access to upload files, use email, use XMPP, etc. How can I prevent that these users go to a certificate authority and get a certificate for my domain? ...
0
votes
1answer
125 views

Code signing certificate validation by Java

Despite several web search, I can’t find an accurate explanation on code signing certificate validation by Java. I am wondering if the code signing certificate (the “final cert”) must already be in ...
0
votes
1answer
99 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 ...
0
votes
1answer
229 views

How does a Certificate Private Key get transferred on import / export?

I am fairly new to certificates in general and have setup my own standalone CA for testing purposes. I have noticed some interesting behavior of private keys which I'm trying to find some ...
2
votes
1answer
277 views

How CERT.rsa is interrelated with PackageInfo signatures

I am a newbie in security and cryptography, but I am developing Android applications and now wanna to dive deeper into the Android security mechanisms. I am trying to understand how CERT.rsa (as I ...
0
votes
1answer
253 views

Creating root CA to issue certificates programatically

I have to generate a self signed root CA and use it to issue to certificates programatically. I am new to security and certificates and I think I am missing some pieces required to make the whole ...
0
votes
0answers
5 views

Invalid certificate problem with Outlook meeting [migrated]

I have a legacy meeting in Outlook, and every week when it occurs I get this popup: I have tried to "change the security settings" and it has no effect. How can I fix this?
7
votes
4answers
30k views

SSL Client Certificate authentication

Is it possible to make a program which uses client certificate authentication with only public and private key (I have not generated any certificate, I have only public and private key). Simply, I ...
1
vote
1answer
42 views

How can I list all self-signed certificates in my stores on a Windows client?

I'm on a mission to list the self-signed certificates ('issued by' and 'issued to' match) on my machine via an automated method. PowerShell is available for use. Preferably the results would be ...
1
vote
1answer
82 views

Is or was it possible to register a wildcard certificate to third level subdomain?

The use of a null byte in a certificate cn is very well known… and I saw this code in a popular smtp server (who obviously thought it didn’t worth to use the gnutls or openssl for doing that kind of ...
5
votes
2answers
92 views

How could mobile developers prevent bypassing certificate pinning with tools such as SSL Kill Switch?

I used SSL Kill Switch on some iOS mobile applications to try to bypass certificate pinning and I was successful. I understand that SSL Kill Switch "kills" the certificate validation process on the ...
5
votes
3answers
137 views

X509 CRL suspended certificates and openssl ca comand

In CRL X509 format we have "Hold Instruction code" for a list of suspended certificates. I know that "its use is strongly deprecated for the Internet PKI", but in my own private CA, I want to use it. ...
0
votes
1answer
357 views

Getting Certificate KeyContainerName to initialize CspParameters

How can I get the name of a Key Container that's in a smart card required for initialization of CspParameters? CspParameters^ cspa = gcnew CspParameters(ProviderType, ProviderName, keyContainerName, ...
1
vote
1answer
122 views

Is using “SHA-256 with RSA-2048 Encryption” a secure certificate hashing algorithm?

Is using "SHA-256 with RSA-2048 Encryption" a secure certificate hashing algorithm? I don't think it is. Two examples: nsa.gov [careers site] give.wfp.org
2
votes
0answers
44 views

Why more Android applications (compared to iOS) use certificate pinning? [closed]

I used mitmproxy to test the same 50 apps on iOS and Android and noticed that more than 50% of the Android applications compared to 23% of iOS, used certificate pinning. Is there any explanation as ...