SSL (Secure Sockets Layer) and/or TLS (Transport Layer Security)

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11
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2answers
17k views

Advantages of client certificates for client authentication?

I'm no security expert, so please just ask in a comment if I haven't made my question clear enough for an answer. The Scenario We have a server running WCF services, and a number of clients ...
39
votes
6answers
6k views

How does a country block/censor an encrypted website (HTTPS)?

Given that Site X uses HTTPS, how can it be blocked by a country? My browser reads: 128-bit encryption | ECDHE_RSA as key exchange. I say it's blocked since when I use Tor, it works fine. One ...
28
votes
5answers
14k views

Are there security issues with embedding an HTTPS iframe on an HTTP page?

I've seen websites placing HTTPS iframes on HTTP pages. Are there any security concerns with this? Is it secure to transmit private information like credit card details in such a scheme (where the ...
21
votes
3answers
8k views

Which SSL/TLS ciphers can be considered secure?

The OpenSSL website provides a long list of different ciphers available for SSL and TLS. My question is, which of those ciphers can be considered secure nowadays. I am especially interested in HTTPS, ...
16
votes
4answers
5k views

Are there technical disadvantages in using free ssl certificates?

Note this question is related, except this one is about free SSL certs. There are providers who are offering totally free entry-level SSL certs (like StartSSL). I was wondering if they are ...
15
votes
2answers
13k 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. ...
4
votes
3answers
1k views

How to roll my own security mechanism - avoid SSL

i'm looking at implementing my own security mechanism rather than using ssl due to ssl being 'hopelessly broken' http://www.theregister.co.uk/2011/04/11/state_of_ssl_analysis/ and also because it is ...
25
votes
4answers
5k views

Why aren't application downloads routinely done over HTTPS?

We all know we should be using SSL whenever we collect passwords or other sensitive information. SSL provides two main benefits: Encryption: The data can't be read by a middle-man while in transit. ...
16
votes
4answers
2k views

Why does Facebook serve several SSL certificates?

Facebook seems to be alternately serving two SSL certificates, one from DigiCert and one from VeriSign. There are only two reasons for this that I can think of: They're in the middle of a ...
11
votes
2answers
1k views

Is Apple's push notification service implementation vulnerable to a MitM attack

Recently(more info) I've spotted a strange message in the logs on my quite recent, fresh installation of OS X Mavericks 10.9.2 Apr 27 15:26:47 Ivans-MacBook-Pro.local apsd[194]: Unrecognized leaf ...
11
votes
1answer
9k views

Tools to test for BEAST/CRIME that AREN'T Internet-based?

We have increasing pressure to identify and remediate any HTTPS server configurations that are vulnerable to BEAST (CBC) and CRIME (compression). We need to fix servers that are accessible to the ...
7
votes
3answers
3k views

Can someone explain a little better what exactly is accomplished by generation of DH parameters?

I'm setting up a node.js server: https.createServer({ ... ciphers: 'ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH', honorCipherOrder: true }, app).listen(443); ...
7
votes
2answers
2k views

How does DNSSec work? Are there known limitations or issues?

Based on information from this site, DNSSec is needed to protect us from a number of DNS and SSL / TLS hacks, including: DNS spoofing, especially on wifi or shared medium Registrars that abuse their ...
4
votes
1answer
875 views

Whats the best custom compression method to use when I have SSL?

Suppose I have an application which does encryption using SSL and provided you cannot control what cipher suite is being negotiated, and assuming that I have some custom compression over the data ...
13
votes
3answers
221 views

Domain name expiration and TLS

If I purchase a domain name that has expired, do I have any assurance that the previous owner does not have a valid HTTPS certificate for the site? In other words, do CAs check domain name expiration ...
11
votes
7answers
2k views

Should we force user to HTTPS on website?

Should we force website from HTTP to HTTPS , one of the method is using .htaccess: RewriteCond %{SERVER_PORT} 80 RewriteRule ^(.*)$ https://www.example.com/$1 [R,L] But what I notice is that some ...
10
votes
2answers
1k views

Are there really functioning quantum computers?

I saw this video on youtube on quantum computing. It says that a company called dwavesys has already made commercially available quantum computer. I checked on the website and it exists. I thought ...
8
votes
6answers
861 views

when is it safe to click through an SSL warning message?

How does a user know if it's safe to click through scary browser warnings about SSL certificates? Ideally, a user should never need to click through these warning messages, but sometimes honest ...
7
votes
2answers
11k views

How to mitigate SSL/TLS Protocol Initialization Vector Implementation Information Disclosure Vulnerability?

Disclaimer: I'm not a sysadmin, please try to give your answers in developer friendly language ;) I'm test scanning a fresh VPS image with Nessus and I'm getting plugin 58751. I tried figuring out ...
4
votes
1answer
271 views

Apart from the lack of native Oultook support, why should one prefer S/MIME over PGP/MIME for email?

From my (still quite subjective) point of view, GnuPG/PGP is superior to SSL (or more specifically, PGP/MIME over S/MIME; maybe in other areas SSL is the better choice), e.g. due to the support of ...
4
votes
3answers
3k 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 ...
19
votes
4answers
857 views

How can a web application protect IE users when this browser doesn't support HSTS?

HTTP Strict Transport Security (HSTS) is a very useful feature at preventing OWASP a9 violations and attacks like SSLStrip which try and prevent the client from making a secure connection. My ...
14
votes
2answers
1k 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 ...
8
votes
1answer
409 views

Build a secure channel without SSL/TLS

I'm looking at possible options to build a secure channel between multiple embedded devices with limited cryptography capabilities and an HTTP server (It could be some sort of web service). 1. ...
8
votes
1answer
2k views

How should I store SSL keys on the server?

I have a Node.JS HTTPS webserver instantiated as follows: var privateKey = fs.readFileSync('./../ssl/localhost.key').toString(); var certificate = ...
7
votes
2answers
857 views

Is “Fingerprint Check” enough to verify HTTPS certificates?

So I'm at place A, see this sign: and I'm writing the fingerprints to a piece of paper (this website is just an example): Ok. Then, I go to place B (other country, etc.) then I check this ...
7
votes
2answers
31k views

How to determine if a browser is using an SSL or TLS connection?

I want to know whether my browser is using SSL or TLS connection if I see HTTPS. I want to know for IE, Firefox, Chrome and Safari. I want to know the protocol version.
3
votes
2answers
507 views

Test STARTTLS configuration of SMTP server

Is there an easy way to test an SMTP server to check for configuration issues associated with STARTTLS encryption, and report on whether it has been configured properly so that email will be encrypted ...
16
votes
3answers
6k 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 ...
12
votes
3answers
1k views

Multi-tenancy, SSL Certificates, and Subject Alternative Name

The X509 specification allows a CA to issue a single certificate for multiple hostnames, by using the "Subject Alternative Name" extension. From the spec: The subject alternative name ...
11
votes
4answers
1k views

What kinds of SSL certificates are usable for encryption?

I know that Verizon SSL certificates cost close to $600. There are couple of cheap alternatives, but I never really understood why Verizon does not offer such certificates. Look for RapidSSL at ...
9
votes
2answers
11k views

Specific risks of embedding an HTTPS iframe in an HTTP page

I need help listing the specific risks of embedding an HTTPS iframe that enables credit card checkout inside of an HTTP page. Are there security issues with embedding an HTTPS iframe on an HTTP page? ...
9
votes
1answer
335 views

Why can the validity of an SSL certificate exceed the registration period of a domain?

I can understand why one might desire to purchase a certificate for multiple years but I am left wondering why it appears to be possible to obtain a valid certificate for a domain that may have come ...
9
votes
2answers
3k views

What can an attacker do with a stolen SSL private key? What should the web admin do?

What can an attacker do with a stolen website certificate and key? What should the website admin do upon learning this?
9
votes
2answers
4k views

SSL Certificate revocation check

In the SSL protocol I don't see where the certificate is checked for revocation status. https://developer.mozilla.org/en/Introduction_to_SSL Is the Certificate Revocation and Status Checking not ...
8
votes
3answers
3k views

Preventing a spoofing man in the middle attack?

I was humming along with my usual routine of listening to old Defcon videos trying to understand some of the basics of what's going on in the IT Security world, when I came across one explaining man ...
8
votes
3answers
688 views

How practical/important is the Lucky Thirteen TLS attack?

I was reading this article which talks about a new attack against TLS being called Lucky Thirteen. It claims to allow repeatable MitM attacks against HTTPS connections. It's described as being fairly ...
6
votes
3answers
1k views

Why do websites use HTTPS when they don't need to? [duplicate]

This has been bothering me for a while, but I have noticed that some websites (the first one that comes to mind is XKCD) use HTTPS for no apparent reason. I mean, XKCD is free and accessible to ...
6
votes
1answer
803 views

Choosing an SSL certificate provider

Does it make any difference which provider I get my SSL/TLS certificate from? In particular, what are the pros and cons getting an SSL certificate from Verisign vs getting one from Thawte? Which one ...
6
votes
1answer
3k 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 ...
6
votes
3answers
278 views

How safe are copies of Firefox that are on various Mozilla mirror sites?

If I end up downloading a .dmg or .exe (depending on OS) installer from some mirror site, how can I be sure that a virus or trojan or spyware has not been added? I don't see any mechanism for ...
5
votes
2answers
218 views

Configuring election website to prevent MITM attacks

Consider an election web site that will be used for voting over the Internet. What steps should the administrator of such a web site take to provide adequate security against man-in-the-middle attacks ...
4
votes
4answers
2k views

Is it possible to create a self signed certificate authority?

Would it be possible to create a legitimate certificate with the CA bit set? I dont have a usecase associated with this, I'm merely curious. To explain my question : Suppose I sign a public ...
4
votes
3answers
2k views

Self sign SSL certificate for my mobile app?

My mobile (iOS and Android) connects to my server via a REST API over HTTP. I would like that HTTP to be secure, so HTTPS seems to be the obvious choice. All of the questions about self signing SSL ...
4
votes
3answers
1k views

Is a forced rewrite from http to https secure? What does SSLRequireSSL add?

I've read contradicting advice about forcing https connections in the following way: RewriteEngine On RewriteCond %{HTTPS} off RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} To me it seems ...
4
votes
2answers
4k views

Confusing about Ephemeral Diffie-Hellman

1 Does Ephemeral Diffie-Hellman support authentication? Quote from www.rsa.com/products/bsafe/documentation/mesuite21html/dev_guide/group_EPH_DH.html Ephemeral Diffie-Hellman does NOT provide ...
4
votes
2answers
2k views

Next Microsoft Patch Tuesday include BEAST SSL fix

http://thehackernews.com/2012/01/next-microsoft-patch-tuesday-include.html I thought the vulnerability that BEAST uses is already fixed on "Microsoft" side, no? Can someone please clarify this?: ...
3
votes
2answers
483 views

SSL/TLS: Version Change during Renegotiation or Resumption?

Can the version proposed by Client be changed during SSL Resumption or Renegotiation? Resumption Case: In case of Resumption, as I understand, Client will send a Client Hello with the Session ID of ...
2
votes
3answers
2k views

Where does StartSSL generate the cerificate, server or client-side?

I.e. do really only I have the private key or do I have to trust that StartSSL (or any other provider) don't store it themselves?
2
votes
3answers
257 views

Help with SSL teaching material

I am taking a course on security next month. As the concepts of SSL/TSL are bit hard. I am looking for a nice way of presenting it to my students. They are Compsci undergrads. It would be nice to ...