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

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321
votes
3answers
114k views

How does SSL work?

How does SSL work? I just realised we don't actually have a definitive answer here, and it's something worth covering. I'd like to see details in terms of: A high level description of the protocol. ...
66
votes
15answers
6k views

Does an established ssl connection mean a line is really secure

From the view of somebody offering a webapplication. When somebody connects with SSL (https) to our service and submits the correct authentication data, is it safe to transmit all sensitive data over ...
46
votes
13answers
7k views

What are the pros and cons of site wide SSL (https)?

What are the pros and cons of encrypting all HTTP traffic for the whole site through SSL, as opposed to SSL on just the login page?
175
votes
8answers
15k views

How is it possible that people observing an HTTPS connection being established wouldn't know how to decrypt it?

I've often heard it said that if you're logging in to a website - a bank, GMail, whatever - via HTTPS, that the information you transmit is safe from snooping by 3rd parties. I've always been a little ...
185
votes
3answers
41k views

CRIME - How to beat the BEAST successor?

With the advent of CRIME, BEAST's successor, what possible protection is available for an individual and/or system owner in order to protect themselves and their users against this new attack on TLS?
27
votes
11answers
3k views

How feasible is it for a CA to be hacked? Which default trusted root certificates should I remove?

This question has been revised & clarified significantly since the original version. If we look at each trusted certificate in my Trusted Root store, how much should I trust them? What factors ...
24
votes
10answers
823 views

Does hashing a file from an unsigned website give a false sense of security?

Consider this. Many websites with software downloads also make available MD5 or SHA1 hashes, for users to verify the integrity of the downloaded files. However, few of these sites actually use HTTPS ...
38
votes
3answers
9k views

Are all SSL Certificates equal?

After running a few tests from Qualsys' SSL Labs tool, I saw that there were quite significant rating differences between a GoDaddy and VeriSign certificate that I have tested against. Are all SSL ...
56
votes
3answers
29k views

What clients are proven to be vulnerable to Heartbleed?

On several pages, it is re-iterated that attackers can obtain up to 64K memory from the server or client that use an OpenSSL implementation vulnerable to Heartbleed (CVE-2014-0160). There are dozens ...
25
votes
8answers
12k views

Can my company see what HTTPS sites I went to?

At work my company uses internet monitoring software (websense). I know if I visit a https ssl-encrypted site (such as https://secure.logmein.com) they can't see what I'm doing on the site since all ...
14
votes
4answers
4k views

Options when defending against SSLstrip?

I'm wondering, does anyone have any suggestions to defend against SSLstrip particularly?
21
votes
5answers
13k views

What ciphers should I use in my web server after I configure my SSL certificate?

There are many great questions that ask what is the best certificate to use for a website; but once the certificate is purchased, there is also the possibility to choose or edit the Cipher list. ...
20
votes
2answers
15k views

Does https prevent man in the middle attacks by proxy server?

There is a desktop client A connecting to website W in a https connection A --> W Somehow between A and W, there is a proxy G. A --> G --> W In this case, will G be able to get the ...
15
votes
1answer
2k views

Guidance for implementors of HTTPS-only sites (Server side)

The recent trend in HTTPS attacks is to attack the HTTP protocol. What should I do to increase my site's security if the only protocol I want is HTTPS? Some easy to implement ideas are Implement ...
37
votes
4answers
21k views

What is certificate pinning?

I'm superficially familiar with SSL and what certs do. Recently I saw some discussion on cert pinning but there wasn't a definition. A DDG search didn't turn up anything useful. What is certificate ...
7
votes
2answers
2k views

What are the advantages of EV Certificate?

What are the various advantages of using extended validation (EV) certificates than normal certificates which also provide comparatively high degree of encryption like RC4, 128 Bit? I know that the ...
73
votes
3answers
43k views

What's the difference between SSL, TLS, and HTTPS?

I get confused with the terms in this area. What is SSL, TLS, and HTTPS? What are the differences between them?
34
votes
6answers
2k views

Why is HTTPS not the default protocol?

Why is HTTP still commonly used, instead what I would believe much more secure HTTPS?
17
votes
3answers
8k views

Is there a way to mitigate BEAST without disabling AES completely?

It seems that the easiest way to protect users against the BEAST attack on TLS <= 1.0 is to prefer RC4 or even disable all other (CBC) cipher suites altogether, e.g. by specifying something like ...
22
votes
3answers
12k views

What steps do Gmail, Yahoo! Mail, and Hotmail take to prevent eavesdropping on email?

I would like to ask what happens when an email is sent from gmail, yahoo or hotmail public web email services? I don't understand email protocols in details, but as far as I know email traffic is ...
15
votes
5answers
1k views

What can I do about TLS 1.0 javascript injection vulnerability on my server?

The recent article featured on slashdot http://www.theregister.co.uk/2011/09/19/beast_exploits_paypal_ssl/ says that connections secured with TLS 1.0 are susceptible to man-in-the-middle decryption ...
54
votes
7answers
21k views

Is BASIC-Auth secure if done over HTTPS?

I'm making a REST-API and it's straight forward to do BASIC auth login. Then let HTTPS secure the connection so the password is protected when the api is used. Can this be considered secure?
55
votes
4answers
20k views

Does Heartbleed mean new certificates for every SSL server?

If you haven't heard of the Heartbleed Bug, it's something to take a look at immediately. It essentially means that an attacker can exploit a vulnerability in many versions of OpenSSL to be able to ...
23
votes
4answers
5k views

BREACH - a new attack against HTTP. What can be done?

Following on from CRIME, now we have BREACH to be presented at Black Hat in Las Vegas Thursday (today). From the linked article, it suggests that this attack against compression will not be as simple ...
41
votes
8answers
8k views

Is there any technical security reason not to buy the cheapest SSL certificate you can find?

While shopping for a basic SSL cert for my blog, I found that many of the more well known Certificat Authorities have an entry-level certificate (with less stringent validation of the purchaser's ...
17
votes
2answers
798 views

Are URLs viewed during HTTPS transactions to one or more websites from a single IP distinguishable?

For example, say the following are HTTPS URLs to two websites by one IP over 5 mins: "A.com/1", "A.com/2", "A.com/3", "B.com/1", "B.com/2". Would monitoring of packets reveal: nothing, reveal only ...
17
votes
3answers
31k views

Understanding 2048 bit SSL and 256 bit encryption

On DigiCert's page, they advertise a 2048 bit SSL with a 256 bit encryption: http://www.digicert.com/256-bit-ssl-certificates.htm What exactly is the difference here and why are two encryption bits ...
14
votes
7answers
1k views

Can a HTTPS connection be compromised because of a rogue DNS server

If I'm visiting (just a desktop pc, client side) a site that has a valid HTTPS cert/connection, that can it be compromised if I'm using [not with free will, so e.g.: I'm "attacked"] a rouge DNS ...
2
votes
3answers
6k views

How commonly are SSL/TLS or S/MIME used by e-mail providers?

I was reading through different posts here about email security. After reading these I still have some questions. I understand that S/MIME can be used to transfer email securely between servers. ...
41
votes
4answers
9k views

Is posting from HTTP to HTTPS a bad practice?

Working on the assumption that SSL serves both to encrypt data and to provide assurance as to the identity and legitimacy of the website, should the practice of providing a logon form on a page ...
39
votes
4answers
24k views

What is the difference between an x.509 “client certificate” and a normal SSL certificate?

I am setting up a web service through which my company will talk to a number of business customers' services. We will be exchanging information using SOAP. I would like to handle authentication with ...
17
votes
1answer
6k views

My understanding of how HTTPS works (gmail for example)

I want to ask if my below understanding is correct or not regarding the HTTPS used for the webpage we are visiting. I will use Gmail as an example: My laptop tries to connect to the Gmail server ...
24
votes
2answers
5k views

I just send username and password over https. Is this ok?

When a user's logging in to my site, they send their username and password to me over https. Besides the ssl, there's no special obfuscation of the password - it lives in memory in the browser in the ...
18
votes
2answers
4k views

symmetric encryption session keys in SSL/TLS

This question concerns the session send and receive keys used in SSL/TLS protocol. my understanding is that this key uses symmetric encryption (DES, AES, BlowFish, etc.) I'm wondering, if ...
15
votes
5answers
1k views

Security of an initial redirection from http://example.com to https://example.com

Suppose that http://example.com/<foo> systematically redirects to https://example.com/<foo>. I enter http://example.com in my browser's URL bar, and I see a page load and the URL bar now ...
33
votes
9answers
10k views

Is visiting HTTPS websites on a public hotspot secure?

It's often said that HTTPS SSL/TLS connections are encrypted and said to be secure because the communication between the server and me is encrypted (also provides server authentication) so if someone ...
24
votes
3answers
1k views

What is an SSL certificate intended to prove, and how does it do it?

If I get an SSL certificate from a well-known provider, what does that prove about my site and how? Here's what I know: Assume Alice and Bob both have public and private keys If Alice encrypts ...
23
votes
3answers
2k views

How does Convergence (CA replacement) prevent its notaries from being MITM'd as well?

I have been looking into Convergence and how it works, but I cant figure out how it is effective against a MITM attack that happens near the target system. My understanding is that Convergence works ...
19
votes
1answer
3k views

TLS: RC4 or not RC4?

I was reading another interesting article by Matthew Green today, saying that if you're using RC4 as your primary ciphersuite in SSL/TLS, now would be a great time to stop As far as I'm aware ...
15
votes
4answers
2k views

What is the potential impact of these SSL certificate validation vulnerabilities?

I just finished reading through this paper by Georgiev et al, which demonstrates a wide range of serious security flaws in SSL certificate validation in various non-browser software, libraries and ...
14
votes
3answers
6k views

What are the risks of self signing a certificate for SSL

Let's say I sign a SSL certificate for myself, and I'm not using a certified CA. What are the risks and/or threats of doing it?
25
votes
7answers
3k views

Does it matter which Certificate Authority I source my SSL Certificate from?

To secure my web site with HTTPS, does it matter which company I source my SSL certificate from, or just that the browser recognizes it? From the Area51 proposal.
19
votes
7answers
23k views

What is the difference in security between a VPN- and a SSL-connection?

I would like to design a client-server application where the server is placed on Internet. I assume that I could set up the client-server connection using VPN (is it using IPSec?) or using a SSL ...
16
votes
8answers
2k views

Should a site have SSL if it doesn't have a login form?

We have a site at work that is used for the following: Our homepage, which is just some info and contact info. Job applications are also handled on our site. There is no place where you can login ...
11
votes
2answers
2k views

What should I know before configuring Perfect Forward Secrecy?

PFS has gained attention in our audit department because of its' innate ability to limit our exposure if someone steals our private key. What pitfalls or common mistakes should I be aware of before ...
10
votes
5answers
2k views

Can Javascript/Flash verify the SSL connection to prevent “SSL Inspection”?

I'd like to determine if an SSL webpage is being debugged through Fiddler, or if it's going through an SSL Proxy. So some people may ask What is the point of re-validating SSL using javascript? ...
13
votes
6answers
1k views

How secure is redirecting user from http://normal.bank.com to https://secure.bank.com?

I have an application. Which works on http, http://normal.bank.com. But for log-in, performing any action, etc. I am rediecting user to https://secure.bank.com, where user can login and perform ...
7
votes
3answers
562 views

Is a mobile app more secure for mobile use than the “normal” website?

An untrained end user who uses a mobile web browser is vulnerable to phishing and can't easily verify the the authenticity (or security) of a website among other issues. Also, it is very easy to ...
95
votes
8answers
4k views

Attacking an office printer?

I did an nmap scan on an advanced office printer that has a domain name and is accessible from outside the corporate network. Surprisingly I found many open ports like http:80, https:443, and ...
73
votes
2answers
37k views

What is the difference between https://google.com and https://encrypted.google.com?

Is it there any difference between the encrypted Google search (at https://encrypted.google.com) and the ordinary HTTPS Google search (at https://google.com)? In terms of security what were the ...