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32

The purpose of the warning is that by using HTTPS, there is an expectation of proper security, but a self-signed or expired certificate has vulnerabilities that the user needs to be aware of. The "risk" is that one thinks they are properly secured, but they are not fully secured, as opposed to HTTP, where one knows there is no encryption at all. There ...


23

From what I understand, no, Cloudflare couldn't work any other way. Cloudflare analyses the connection before passing it to your webserver to ensure that it's correct and coming from a legitimate client. In order to do this, it needs to be able to see the contents of each packet from and to your server. With SSL/TLS, each packet is encrypted and therefore ...


21

If you look at the Heartbleed summary: The Heartbleed Bug is a serious vulnerability in the popular OpenSSL cryptographic software library. This weakness allows stealing the information protected, under normal conditions, by the SSL/TLS encryption used to secure the Internet. SSL/TLS provides communication security and privacy over the Internet ...


18

Security difference First, let's talk about SSL (now called TLS by the way), which adds the 'S' at the end of HTTPS and is in charge of "securing the communication". The clue to answer this question is indeed to fully understand what we mean by "securing the communication". SSL, no matter if it is a self-signed certificate which is being used or one signed ...


10

SSL/TLS are protocols. OpenSSL is an implementation of these protocols. It has two libraries: libcrypto which implements a set of encryption algorithms, and libssl which implements TLS protocols and its previous SSL. If there is an error in the implementation of a given protocol, it does not mean the problem is the protocol itself. HeartBleed is just a ...


8

It can't work any other way because the way cloudflare works is that they mirror your files for your users on their own servers. To request the files, clients connect to Cloudflare instead of your server. That means their browsers expect that the connection is encrypted with a valid TLS certificate from cdn.cloudflare.com, not from your website. End-to-end ...


10

If you've empirically verified that it functions as proposed* then you should notify the OpenSSL security team. The impact of this bug would potentially be on the Denial-of-Service spectrum; basically, you can force a client/server pair to perform full negotiations each time, which takes up more server resources (...which is why resumption exists in the ...


7

Tor provides anonymity which HTTPS does not provide. HTTPS only provides end-to-end encryption, but a man in the middle can still see where you are connecting to and might find out more (i.e. which sites your are looking at in detail) by doing statistical analysis of the sniffed traffic. Tor tries its best to hide the meta-information like source and ...


5

In short, they're both crypto key generation tools, but keytool has the additional feature of manipulating Java's preferred key storage file format, the KeyStore. Java strongly prefers to work with keys and certificates that are stored in a KeyStore (also called a TrustStore when it's only got certificates in it). It is possible, but not trivial, to get ...


5

What browsers do is subject to change at the whims of whoever maintains them, and they do so without any proper documentation. The treatment of wildcards in dNSName entries in certificates is formally defined in RFC 2818, which would imply that, e.g., *.*.example.com would match a subdomain name that's two levels down example.com; it also says that f*.com ...


5

As with all things in security, using HTTPS is a trade-off. You're trading some performance and potentially customer inconvenienace for improved security and other possible benefits (for example google boosting the ratings of SSL enabled sites). Only you can answer whether that's worth it, as only you know what your site does and whether the trade-off is ...


5

The other answers are right that in practice Cloudflare can't provide their full services as effectively without introducing this kind of security risk. Roughly speaking, Cloudflare does two things: They mirror your site, and can serve it from their own servers (their CDN). This way, if your site is getting hit with a DDoS, they can absorb the traffic ...


5

Potentially Cloudflare could work in a pass-thru SSL mode. However, it would not be as good at protecting against DDoS attacks. In pass-thru mode, clients would make a TCP connection on port 443 to Cloudflare, which is forwarded to your web server. The SSL setup takes place between the client and your web server, so while the connection goes through ...


4

Without warnings for things like self-signed or expired certs, inappropriate cipher suite selections, and other bad HTTPS configurations, the presentation of a website's state of security to the user becomes binary - either you have HTTPS on the site, or you don't. This would hide a number of nuances which can significantly affect exactly how much the "S" in ...


4

If I am not mistaken, importing your own SSL certificates is just for the connections which you make to the device's own web interface so that won't help you to accomplish your goal. What you would need to do is: Create your own root CA Make those devices trust your own root certificate Redirect all SSL traffic from those devices to your proxy When a ...


4

Tor provides you anonimity. HTTPS protects (encrypts) the content of your data. HTTP does not provide none of these. Tor provides anonymity but does not protect the exploitation of an insecure application to reveal the IP address of, or trace, a TCP stream. Running HTTP over Tor means your communication data could be read and thus compromising your ...


4

@atdre points to a tool that should allow detecting whether a given server supports TLS 1.2, but this is only part of the story. In SSL/TLS, the initial steps of a connection are the handshake in which a number of parameters are agreed upon between client and server, including the protocol version that will be used. The client announces the highest protocol ...


3

Is there a way for a TLS client to inform the server that it doesn't intend to resume its authenticated session(s) anymore? Yes, by sending an Alert with a Fatal severity. From RFC 5077: 5.1. Invalidating Sessions The TLS specification requires that TLS sessions be invalidated when errors occur. This is an apparent reference* to the ...


3

Will browsers recognize HPKP header on subdomain if I set it only on domain.tld and add includeSubdomains in it? If the user never visits domain.tld and the HPKP header is only send on requests to this domain then the browser will never see the HPKP header. But only after the browser has seen the header it has any effect. Once the browser has seen the ...


3

Active assessment of all known IP addresses and hostnames is the best method to audit an infrastructure to full compliance. sslyze --sslv2 --sslv3 --tlsv1 --tlsv1_1 --targets_in=target-list.txt --xml_out=sslyze.xml You can get sslyze here -- https://github.com/nabla-c0d3/sslyze You may also need a developer who understands XML parsing in order to best ...


3

You may also want to look at this question, which also touches on the subject. I understand that an SSL / TLS certificate, verified by a public CA, will enable transport security on SMTP between servers. However, I don't see how this could help with transport security between the server and a client. At best, it seems like the client's outgoing ...


3

You can have a backup certificate from a different CA but you cannot serve multiple leaf certificates (i.e. certificates matching the hostname) within the same TLS connection. You can also not have multiple signatures (i.e. by different CA's) on the same certificate which is a similar question often asked in this context. But you could use different ...


2

What's the content of your website? Is it anything anyone anywhere in the world could want to access without other people knowing about it (governments, marketers, snoops on the same wifi network)? Remember that what might be perfectly acceptable to view in your culture might not be acceptable elsewhere (like opinions about politics, sexuality or religion). ...


2

TLS only allows a single cert. You'd need to have some monitoring in place to check for this issue and automatically reconfigure your web server upon occurrence. You can get the same CSR signed by multiple CAs. Each time you will get a separate cert signed by that single CA. You are likely better off with completely independent keypairs and CSRs for each ...


2

These answers are great. But I often have to give a simplified answer without all the jargon. HTTP - It is not encrypted and the data sent over the line could be easily read. HTTPS - It is encrypted and verified by a trusted party the data is being handled by the correct source. HTTPS (Self Signed) - It is encrypted but there is no verification by a ...


2

A certificate is your public key and some information about the site and then a lifetime. All this is signed by the issuer CA. The certificate is public and thus also the public key, but the private key is not published. One of our SSL certificates has expired and along with that so has the keys. While the certificate will expire the public and ...


2

With modern Intel CPU's (and we're talking 5-7 years now...) there is no significant performance hit on the computation involved in an SSL connection. So - from a performance perspective there is no reason not to use SSL everywhere. Another caveat is the vulnerability of mixed content on your page. You should not be referencing HTTP resources on an ...


2

No, there is no restriction coming from the TLS protocol version with regards to the hash function used by a CA in its signature algorithm. In TLS 1.2 the client can advertise both the signature algorithms and the hash functions that it supports; this is done in the signature_algorithms extension, which is optional. A given client may perfectly well send ...


1

Both OpenSSL and keytool have the same purpose: generating/storing keys and certificate(s) (chaines). The thing is that Java can only work with certificates/keys contained within its keystore (JKS). Those certificates and keys are generated using the keytool library, not by using openssl. As you rightly pointed out, keytool will always need a keystore in ...


1

The Pre-Master Secret is derived from the above random numbers (except where Diffie-Hellman is used). It is then encrypted with the Server's Public Key and sent to the Server. the catch is, this encrypted message can ONLY be decrypted by the Server's private key. so if an attacker knows/has the server's private key(the golden key), then its all over already ...



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