Questions tagged [tls]

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

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74
votes
9answers
10k views

Why is HTTPS not the default protocol?

Why is HTTP still commonly used, instead what I would believe much more secure HTTPS?
74
votes
4answers
83k views

“Optimal” Web Server SSL Cipher Suite Configuration

Over the last couple of years there have been a number of changes in what would be considered an optimal SSL cipher suite configuration (e.g. the BEAST and CRIME attacks, the weaknesses in RC4) My ...
73
votes
4answers
34k 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 ...
73
votes
1answer
16k views

How can Kazakhstan perform MITM attacks on all HTTPS traffic?

There is now MITM on HTTPS traffic in Kazakhstan. But for MITM to work, other than installing the certificate, there has to be someone proxying the request, right? Will that role be played by the ...
72
votes
8answers
56k views

Need to access old forgotten router that only supports SSLv3

I need to access the web interface of a router standing here in the office. The problem is that it only supports SSLv3 and I cannot find a browser that allows me to connect to it. In order to update ...
72
votes
5answers
15k views

What makes Let's Encrypt secure?

Let's Encrypt is an initiative from the Electronic Frontier Foundation (EFF), Mozilla, Cisco, Akamai, IdenTrust, and researchers at the University of Michigan that aims to automatically provide every ...
71
votes
6answers
56k views

Does SSL/TLS (https) hide the urls being accessed [duplicate]

Suppose I type this in my browser https://www.mysite.com/getsecret?username=alice&password=mysecret and an attacker is watching all traffic from me to my ISP. What information is protected by ...
71
votes
5answers
69k views

How do I run proper HTTPS on an Internal Network?

This question has been asked several times, I'll link a few: https://superuser.com/questions/791015/https-over-private-network https://stackoverflow.com/questions/616055/https-certificate-for-...
69
votes
3answers
11k views

Why is Google still using a sha1 certificate on its own site when they are phasing them out in Chrome?

Firefox dev tools shows that https://www.google.com is using a certificate signed with SHA1. Why is Google doing this when they are phasing out the certificate themselves? Shouldn't this only hurt ...
69
votes
1answer
10k views

Why is there no certificate error while visiting google.net although it presents a certificate issued to google.com?

The following output shows that google.net is presenting a certificate that has been issued to www.google.com. $ openssl s_client -connect google.net:443 < /dev/null > out.txt 2>&1; cat ...
68
votes
3answers
8k 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 ...
67
votes
3answers
12k views

Why is Firefox (and only Firefox) reporting that my connection is insecure on multiple sites?

After installing Firefox 54.0.1 on my work laptop, the first page I see warns me that "Your connection is not secure" when opening https://www.mozilla.org/. "The owner of Firefox has configured their ...
67
votes
3answers
8k views

Heartbleed: Why does the client supply the length of the message at all?

"The fix for this bug is simple: check that the length of the message actually matches the length of the incoming request." Why do we even have the client report the length at all? If we can know ...
66
votes
8answers
17k views

Why use HTTPS Everywhere when we have HSTS supported browsers?

I know that the browser's default protocol to access any site is http:// when https:// is explicitly not mentioned, but even then if we browse to a website say www.facebook.com, the response header ...
66
votes
3answers
26k 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 public-...
65
votes
4answers
372k 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.
65
votes
8answers
122k 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 ...
65
votes
1answer
17k views

Why does Gmail (add accounts) using SMTP server recommend SSL instead of TLS?

I stumbled something interesting today when I was adding an account to my gmail one. Why is SSL boldly stated as recommended when TLS supersedes SSL? The links for SSL and TLS is the same: https://...
64
votes
4answers
19k 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 ...
63
votes
3answers
175k 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 ...
63
votes
1answer
37k views

Are SSL encrypted requests vulnerable to Replay Attacks?

Are SSL encrypted requests vulnerable to Replay Attacks? If so, what are good options to prevent this?
62
votes
4answers
8k views

Why was the private key of the Superfish certificate so easily extractable?

Robert Graham detailed on the Errata Security blog how he was able to get the private key of the Superfish certificate. I understand that attackers can now use this key to generate certificates of ...
62
votes
7answers
62k views

Trying to make a Django-based site use HTTPS-only, not sure if it's secure?

The EFF recommends using HTTPS everywhere on your site, and I'm sure this site would agree. When I asked a question about using Django to implement HTTPS on my login page, that was certainly the ...
61
votes
4answers
10k views

Is there a way to make sure my government does not swap out SSL certificates?

I was recently wondering whether there exists a way to make sure my government is not swapping out SSL certificates in order to intercept the traffic. I know almost all browsers are complaining in ...
60
votes
5answers
50k views

What layer is TLS?

TLS stands for "transport layer security". And the list of IP protocol numbers includes "TLSP" as "Transport Layer Security Protocol". These two things would leave me to believe that TLS is a ...
60
votes
12answers
8k views

Is there ever a good reason _not_ to use TLS/SSL?

While writing an answer to this question on Server Fault, a thought that has been bouncing around my head for quite some time resurfaced again as a question: Is there ever a good reason to not use ...
59
votes
8answers
17k views

How can I securely develop a local webapp at a coffee shop?

When I'm developing a webapp, let's say a Django site, I run it locally and typically access it at http://localhost. I thought this was inherently secure because I assumed that localhost can only be ...
59
votes
6answers
17k views

What's the difference between using HSTS and doing a 301 redirection?

If I already have done a 301 redirection from all the HTTP inner pages to HTTPS, why should I use HSTS as well?
59
votes
8answers
49k views

Why do browsers default to http: and not https: for typed in URLs? [duplicate]

When I type example.com without any scheme into the browser bar and press Enter it is interpreted as HTTP://example.com, not HTTPS://example.com. Why? And where are the plans to fix this? (To be ...
59
votes
4answers
28k 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 ...
58
votes
3answers
26k views

What kind of attack is prevented by Apache2's error code AH02032 (“Hostname provided via SNI and hostname provided via HTTP are different”)?

I saw in my Apache2 server logs messages like [ssl:error] [pid 28482] AH02032: Hostname xxx.yyy.zzz.www:443 provided via SNI and hostname xxx.yyy.zzz.www provided via HTTP are different One of ...
58
votes
4answers
5k views

What security risks are posed by software vendors deploying SSL Intercepting proxies on user desktops (e.g. Superfish)

There has been quite a bit of concern noted relating to the recent discovery that Lenovo are pre-installing a piece of Adware (Superfish) which has the capability of intercepting SSL traffic from ...
58
votes
4answers
16k 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. ...
57
votes
6answers
86k views

SSL with GET and POST

I'm pretty new to security, so forgive my basic question, but does SSL encrypt POST requests but not GET requests? For instance, if I have two requests GET: www.mycoolsite.com/index?id=1&type=...
57
votes
3answers
7k views

Is it common practice for companies to MITM HTTPS traffic?

My company has just introduced a new VPN policy whereby once connected all traffic is routed the company network. This is to allow for improved monitoring of data theft. It would appear that this ...
57
votes
1answer
4k views

Does a client certificate identify the owner to unrelated websites?

If I install a client certificate in my browser, which websites can see any information about this client certificate or the CA that issued it? I once visited an ssl diagnostic site that immediately ...
56
votes
2answers
96k 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 ...
56
votes
2answers
49k 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?
55
votes
2answers
10k views

Why does SSL Labs now consider CBC suites weak?

Why does SSL labs now mark CBC 256 suites as weak, although equivalent GCM and ChaCha20 are considered strong? Until a few months ago, it was unmarked in reports (neither explicitly as weak or strong),...
54
votes
4answers
31k views

Why do HTTPS requests include the host name in clear text?

I'm having a little bit of trouble understanding why the HTTPS protocol includes the host name in plain text. I have read that the host name and IP addresses of an HTTPS packet are not encrypted. Why ...
53
votes
5answers
7k views

Is there any way for my ISP or LAN admin to learn my Gmail address as a result of me logging into Gmail's web interface through via their network?

The title says it all, really. I'm Alice, and I want to login to Gmail's web interface through my browser. Ike, the internet service provider, and Adam, the local network administrator, would like to ...
52
votes
9answers
58k views

What does this Https - “not fully secure” warning mean?

I went to sign into a website today using Google Chrome and was presented with the following error: Your connection to this site is not fully secure Attackers might be able to see the images ...
52
votes
2answers
31k 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 ...
50
votes
7answers
15k views

VPN + HTTPS = 100% anonymous?

Let's say I visit Twitter using HTTPS and a VPN First, I know that HTTPS is end-to-end encrypted, so no one except Twitter can know what data is sent, not even the VPN provider. Second, I know that ...
50
votes
11answers
8k views

SSL's (security) benefit to the website owner

I know the many benefits of SSL for the users of a website. It creates a contract whereby the user can be certain that the entity they're transacting with is who it claims to be and that the ...
49
votes
4answers
15k views

Is SSL dying? Should I buy SSL certificates for my sites any more?

I'm planning to purchase a SSL certificate for one of my sites when I'm concerned about points made in these articles: WiredTree: The Most Significant Issue With SSL – And How To Solve It ...
49
votes
5answers
10k views

How does a country block its citizens from accessing a site?

Following Turkey's recent social site blocks, I am wondering how can you efficiently accomplish that as a country. Similar for a big company. Blocking IPs → easy to circumvent, (proxys, tunnels, etc)...
48
votes
6answers
13k 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 ...
48
votes
2answers
62k views

Decrypting TLS in Wireshark when using DHE_RSA ciphersuites

How can I decrypt TLS messages when an ephemeral Diffie-Hellman ciphersuite is used? I am able to expose the premaster secret and master secret from the SSL Client. Using that, how to decrypt the ...
48
votes
2answers
65k views

Why is it possible to sniff an HTTPS / SSL request?

I'm new to the realm of HTTP requests and security and all that good stuff, but from what I've read, if you want your requests and responses encrypted, use HTTPS and SSL, and you'll be good. Someone ...

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