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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Reset Windows trusted certificates store to its default

Over the time I have installed several additional trusted CA certificates to Windows trust store, sometimes because an app pushed me to do so, some other times for development and testing. Is there ...
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5answers
5k views

Does HTTPS Everywhere defend me against sslsniff-like attacks?

http://www.thoughtcrime.org/software/sslsniff/ If I have a domain on my HTTPS Everywhere list, so that theoretically it could be only visited via an HTTPS connection in my Firefox, then could an ...
21
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3answers
7k views

Is SHA1 weak for SSL?

I noticed that today after I scanned a site on the Qualys SSL Labs site that SSL ciphersuites which use SHA1 are now highlighted as being "Weak". It seems this has just happened; I scan sites pretty ...
14
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2answers
20k views

What's the difference between X.509 and PKCS#7 Certificate?

Am I correct calling file with .p7b file extension saved as 'Cryptographic Message Syntax Standard - PKCS#7 Certificates (.P7B)' in Windows - a 'PKCS#7 certificate'? Or is it better called 'X.509 ...
8
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1answer
3k views

How does adding a random serial number improve a certificates' security?

This article says: "Finding collisions is a tricky process, since it requires you to muck with the bits of the public key embedded in the certificate (see this paper for more details). Also, ...
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4answers
37k views

Expired SSL Certificate Implications

What are the security implications of an expired SSL certificate? For example if an SSL certificate from a trusted CA has expired will the communication channel continue to remain secure?
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4answers
15k views

What vulnerabilities could be caused by a wildcard SSL cert?

In a comment on this answer, AviD says: "There are numerous security issues with wildcard SSL certs." So, what are the problems? I understand that the same private key is being used in multiple ...
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5answers
2k views

Why are certificates limited in time?

If a certificate has a limited duration of, say 5 years, but it gets somehow compromised after 2 years, waiting the 3 remaining years for it to get invalid is not a real solution to the breach ...
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3answers
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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
2k views

SSL fingerprint inconsistency: what does it mean?

I apologize if this is not the best place to ask my question on the stackexchange network, I couldn't figure out where to get enough attention and be relevant. Facebook provides a SSL host, it can be ...
12
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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. ...
6
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3answers
5k views

What does it mean for a digital certificate to be “signed”?

When someone says that a particular digital certificate (like an SSL cert) has been "signed with a key", what does that imply? Does that mean the certificate simply includes a key that should be used ...
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2answers
16k views

OpenSSL generate different types of self signed certificate

Does anyone know how to use OpenSSL to generate certificates for the following public key types: DSA - For DHE_DSS key exchange. Diffie-Hellman - For DH_DSS and DH_RSA key exchange. ECDH - For ...
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10answers
5k views

Can an HTTPS site be malicious or unsafe?

I know it's possible for a computer to be infected just by visiting a website. I also know that HTTPS websites are secure. To my understanding, "secure" here refers to "immune to MITM attacks", but ...
15
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3answers
3k views

Can a wildcard SSL certificate be issued for a second level domain?

Something like *.com or *.net? How about *.edu.au? The RFC 2818 does not say anything about this topic.
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1answer
702 views

Kaspersky Antivirus “secure connection scan” as broken as Superfish?

I've read a lot about Superfish (and similar ad-ware) lately and I basically understand the vulnerability to MITM attacks. But I'm actually wondering if the "secure connection scan" by Kaspersky ...
10
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3answers
5k views

How does an SSL server prove its identity?

This document says that a challenge response authentication proves the servers identity. But is a man in the middle attack still possible if the client does not verify domain name ? Please help me ...
7
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1answer
2k views

How do I learn Cryptographic/Mathematical notation

I asked a question earlier where it was recommended that I describe my issue using standard cryptography notation. How do I learn this notation and how to convey my approach? How can I annotate this ...
12
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3answers
7k views

Why is my Positive SSL certificate deemed insecure by Google Chrome? [duplicate]

We run a website over HTTPS with a wildcard certificate from Positive SSL. Today, when I opened Google Chrome (v. 42.0.2311.90 m) and navigated to the site, I noticed a red cross through the https ...
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4answers
2k views

Why isn't OCSP required by default in browsers?

According to the following screenshot, taken from firefox-3.6.17-1.fc14.i686, Firefox has an option to fail closed when unable to connect to OCSP servers. Can someone please explain why this isn't ...
10
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4answers
4k views

HTTPS self signed certficiate for personal website

I want to make my Synology NAS accessible over the internet. When I create my own certificate and import this on all my devices (PC, Laptop, Smartphone, Tablet, etc.) is this as secure as buying a ...
6
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3answers
475 views

On-line cryptographically signed date/time?

I’m looking for a source of on-line cryptographically signed date/time. I do not need a full timestamp service, as I am happy with the information « date/time was that », without a link to a ...
5
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1answer
3k views

google certificates correct CA [closed]

I view certificates of https://www.google.com.ua/ So I thought, when requesting via cURL, if I point by CURLOPT_CAINFO to those certificates (GeoTrust Global CA and Google Internet Authority G2 in ...
3
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2answers
11k views

How to go about an ssl certificate renewal

I've got an ssl certificate from godaddy, and it's time to renew. I ended up with a single "keystore" file, which I give to my webserver (jetty). This is the process I went through to generate the ...
11
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1answer
168 views

How CA ensures that a certificate request is coming from me?

To establish trusted SSL connection I need to create a certificate request. For example, if I use openSSL I can do it by the following command: openssl req -new -key privkey.pem -out cert.csr ...
7
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4answers
2k views

How to prove Bob has received Alice message

I have read up on Digital signature and it is stated that it provides non-repudation. Assuming Alice signs the message using her private key and sends it to Bob, Bob can use Alice's public key to ...
6
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4answers
4k views

Man-in-the-middle Blue Coat proxy SSL or what?

I have just discovered that my workplace has enabled some new features in the Blue Coat network proxy. It seems like all HTTPS certificates in Chrome on Windows are being issued by this internal ...
6
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2answers
2k views

Adding custom data in X.509 certificate

I am using SSL with client authentication. I need to send some extra data while sending the client certificate? Can I send it in the certificate? Can I use the extension fields in certificate for that ...
5
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1answer
1k views

Use Client Certificate using Self Signed CA while using Web Certificate of a publicly trusted CA

I would like to ask if it is possible to use different CA for the client certificate and the web certificate? For example, I would use Verisign to sign my web certificate while I use my Self Sign ...
5
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1answer
4k views

Which extensions to use for a S/MIME certificate?

Analogously to the SSL server certificate question, which extensions should I use for S/MIME, and should the CA be restricted somehow as well? (I'm using openssl, which at the moment creates CA and ...
4
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1answer
93 views

Issuing and managing large numbers of certificates for client authentication

I am developing an Internet of Things product and plan to use client certificate authentication, issuing each "thing" its own certificate on the production line so that it may authenticate with a ...
4
votes
2answers
455 views

Signing my certificate by using my smart card and eID card?

In Belgium we have electronic identity cards (eID) issued by our government. They can be read by a smart card reader. On the card are two certificates, one for signing and one for authentication. I ...
3
votes
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 ...
1
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1answer
431 views

How to make a decent Certificate Signing Request (CSR)?

I'd like to know how to make a decent Certificate Signing Request (CSR) to secure my website and e-mail with a wildcard SSL certificate. With recent exploits as POODLE on SSLv3 and such, I'd like to ...
1
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1answer
5k views

Creating Client Certificates

Consider an application where client certificates are to be used for authentication. The application web server requires SSL and client certificates for all users. In this case, it's IIS 7. I've used ...
0
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1answer
496 views

How do I convert a GPG certificate to a CRT certificate that can be imported into Windows Certificate Manager?

I have a GPG certificate from someone used for email -----BEGIN PGP PUBLIC KEY BLOCK----- Version: GnuPG/MacGPG2 v2.0.14 (Darwin) I would like to import that into Windows Certificate Manager So ...
12
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4answers
2k views

Why is it a good idea that X.509 digital certificates have an expiry date?

What is the benefit of having certificates expire at some fixed date?
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3answers
15k views

What does these warnings mean on an SSL connection by firefox (only)

I am connecting to a secure site and firefox mentions about identity: Owner: This website does not supply ownership information Verified by: Not specified Technical Details: Connection ...
5
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2answers
204 views

Using a verified certificate to sign others

This relates to PKI and certificates generally but websites more specifically. Could you get a verified certificate from a CA that is signed and fine for use, and then use it to sign your own ...
5
votes
1answer
281 views

What issues might exist with TLS-OBC's emulation of Browser Certificates?

TLS-OBC is an RFC proposal that increases SSL/TLS security by using certificates on both ends of the TLS connection. What's special here is that the client is permitted to dynamically create a local, ...
4
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3answers
894 views

Steps to find out whether a SSL certificate is trustworthy

For doing business with a company I have to browse to https://www.prioenergie.de/nc/mein-prioenergie.html (German website). Firefox says the certificate is invalid, because it is not signed by a ...
4
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3answers
1k views

How are possible uses for X.509 (SSL) certificates denoted?

X.509 certificates can be used for servers, clients, email, code signing and more applications. http://twitpic.com/6gdxaq indicates that a certificate can have different of these 'capabilities' on it ...
3
votes
2answers
102 views

Using Self sign certificate in internet

Basically the purpose of SSL cert is for trusting each other. If I have an application that only a few clients I know can use, is generating self sign certs enough? Or do I really need to sign with a ...
3
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3answers
1k views

Self signed certificates for https

Where I work, currently for internal sites, self signed certificates are being used. In Firefox, the info regarding the certificate are displayed: site domain: example.com Owner: Site doesn't supply ...
2
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1answer
478 views

Security Certificates - Tools to Generate Security Certificates

I want to create a self-signed certificate that will be installed as a trusted certificate authority. I then want to create another two certificates which are signed using the private key of the ...
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2answers
413 views

Are there other roots of trust on my computer aside from these 46 root certificates?

I've heard many people imply that modern browsers and OSes trust a myriad of root certificates. The implication is that it is impossible to ensure the private keys of all of the root certificates ...
1
vote
3answers
536 views

Where can I find all SSL CA certificates

I am working on an SSL implementation project and ofcourse I need to verify the certificate presented by the server. To do that I need CA certificates or at least root CA certificates (correct me I am ...
0
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1answer
62 views

Why does not appear the public key from certificate?

I'm creating a certificate in LAMP, the public key is: Public Key: 30 81 89 02 81 81 00 CC CB 64 54 C2 FA A3 7A 81 36 5F 1B D5 10 81 75 B7 42 02 31 83 B1 D5 5A 76 72 6A 77 BE 62 69 16 AB EB 39 66 B5 ...
72
votes
4answers
60k views

What certificates are needed for multi-level subdomains?

I'm working on a web site with a several levels of subdomains. I need to secure all of them with SSL, and I'm trying to determine the correct certificate strategy. Here's what I need to secure: ...
47
votes
2answers
113k views

Difference between .pfx and .cert certificates

What is the difference between .pfx and .cert certificate files? Do we distribute .pfx or .cert for client authentication?