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

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6
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3answers
2k 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); ...
4
votes
1answer
228 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 ...
19
votes
4answers
777 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
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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 ...
9
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
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1answer
317 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. ...
16
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2answers
7k views

ssltest: Chain issues - Contains anchor

I've run ssltest on web application and it found "Chain issues - Contains anchor" (section "Additional Certificates (if supplied)") What does it mean? Should it be fixed? Can it be exploited?
14
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3answers
4k 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 ...
11
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4answers
935 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
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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
637 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 ...
8
votes
1answer
290 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 ...
7
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2answers
25k 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.
6
votes
2answers
432 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 ...
6
votes
3answers
254 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
200 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 ...
5
votes
1answer
658 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 ...
5
votes
1answer
2k 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 ...
5
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
3answers
682 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
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2answers
344 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
244 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 ...
1
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3answers
1k views

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 ...
14
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4answers
1k views

Is my Company Tracking Me?

Every time I try to connect to a site through HTTPS from my office computer, there is a Certificate Error thrown 2-3 times before showing the login screen. Till now I use to ignore this and click ...
12
votes
3answers
550 views

Can I expect my e-mail to be routed securely?

If I connect to my e-mail server via SSL (SMTP/SSL) and the recipient also only checks his e-mail via SSL (web/https or IMAP/SSL), does this - generally speaking - increase the security for the ...
8
votes
1answer
424 views

Is it possible to recognise and prevent MitM attacks on devices which use self-signed SSL certs?

I use both Linux and Windows at work on a large enterprise LAN. The majority of the network configuration is out of my reach. Certain SaaS applications that are hosted locally on the enterprise LAN, ...
7
votes
2answers
551 views

security of PKI, Certificates, certificate authorities, forward secrecy

I want to understand how certificates add to the security of information exchange. Suppose i have a encrypted bidirectional connection between Alice and Bob, using a public key/private key pair. As ...
6
votes
4answers
484 views

Understanding SSL certificate signing

I am trying to understand how SSL certificate and signing and the chain of trust works. I know about root CAs and that they are used to sign intermediate CAs that sign the end certificates that are ...
5
votes
4answers
2k views

Can an intermediate CA be trusted like a self-signed root CA?

Is it possible within the limits of the X.509 specification to mark an intermediate CA as trusted for a specific purpose, e.g. to verify a VPN, HTTPS etc. server key, just like it would work with a ...
5
votes
2answers
1k views

What tools exist to help me monitor OCSP certificate validation failures?

The discussion at Why isn't OCSP required by default in browsers? notes that many browsers by default simply ignore failure to check web site TLS certificate revocation status via the Online ...
5
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6answers
923 views

Should the bit-strength selection of a child certificate be influenced by the CA or the chain?

All things being equal; suppose I have a CA chain that has 1024 bits of RSA encryption. Does this mean that my selection of a child CA or WebServer certificate gains no benefit from a higher level of ...
4
votes
1answer
305 views

Is possible that a TLS server send more than one certificate to the client for the same site?

What I'm trying to archive is enable ECDSA and DSS ciphers in my site, but at the same time not depend just of self signed certificates, so I could sent to my client more than one certificate and them ...
4
votes
2answers
2k views

Certificate Chain checking

I have a very specific question. A client verifies a sever by taking the certificate and checking specific values and that the digital signature of the intermediate CA is correct (According to the ...
4
votes
4answers
1k views

Is online banking more secure on iOS than a desktop computer?

Does Apple's iOS provide a more secure environment for online commerce (banking or shopping) than Windows or Mac OS X? Since the only software that can run on iOS must be vetted by Apple, the ...
4
votes
1answer
1k 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
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
2answers
2k views

Is it possible to connect to a proxy with an ssl (or otherwise encrypted) connection?

What i want to know is whether it is possible to connect to a proxy with an ssl (or otherwise encrypted) connection? (I'm suspecting this is possible because TOR encrypts user connections to it's ...
4
votes
2answers
4k views

Is it possible to decrypt a SSL/TLS session without doing a MITM-attack?

I'm not talking about decrypting the connection while the SSL/TLS is happening (MITM) but after the connection is closed and I have a pcap file of the entire negotiation/data transfer process. How ...
3
votes
2answers
2k views

Do most browsers handle mixed encrypted and unencrypted content correctly?

In Google Chrome, when I go to an encrypted page that contains unencrypted content, I get the following pop-down, which allows me to either load or not load the insecure content, making a clear ...
3
votes
3answers
880 views

Is a company website secure against sslstrip if it doesn't use ssl on homepage but ssl everywhere else?

Most ecommerce websites use SSL/TLS when you want to log. But most have homepage using http only. Is it enough to have SSL/TLS on login page and logged page to prevent sslstrip ?
3
votes
2answers
785 views

Do you require a special type of certificate for using Diffie Hellman as the key exchange protocol in SSL?

In Diffie Hellman key exchange technique both the parties aggree on a common parameter g then they generate their private parameters a and b . Then they exchange g^a and g^b. now they can calculate ...
3
votes
2answers
167 views

self-signed certs that aren't the final certificates in the path

The X.509 spec makes frequent statements like this: (b) If certificate i is self-issued and it is not the final certificate in the path, skip this step for certificate i. How can you have ...
2
votes
1answer
298 views

Different SSL states as seen by Safari, Chrome and Firefox

Today, I visited some sites of the German DHL group. While Chrome and Safari complain about an invalid certificate of Firefox accepts it. Which one is right, which one is wrong? Which decision ...
2
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5answers
519 views

How can a non-technical user verify a message was sent “securely”? …or over TLS?

I have a situation where B2B and B2C communication needs to be sent securely and not visible to most SMTP hijackers. I don't care about conspiracy theories or NSA style attacks, but want to provide ...
2
votes
5answers
844 views

Does the padlock on my browser really indicate a reasonable assurance against eavesdropping?

I know that there have been broken or weak SSL implementations. Do browsers actually have decent standards for what they'll accept and display "the padlock"? Furthermore, are there any practical ...
2
votes
3answers
1k 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 ...
2
votes
2answers
1k views

Secure SSL Session from losing itself into unsecure http

I've seen some implementations of HTTPS SSL and, as a visitor, forced to rely to a lot of those. What would a secure implementation look like and where can one expect problems? I expect the installer ...
17
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3answers
1k views

What are the risks of using a CDN to speed up my website? How do I avoid them?

Content Delivery Networks (CDNs) are well known to speed up the performance of a website, but they create the obvious security risks if someone were to change the code that resides on the CDN. What ...