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30

The short answer: they know a very limited number. HTTP Strict Transport Security was introduced to provide better guarantees that a website is being served over HTTPS when specified by the operator. This works well for websites you have visited recently as your browser will remember their HSTS policy and refuse a plaintext connection. For example, if you ...


16

Security researcher Moxie Marlinspike demonstrated this type of attack in 2009, using a tool that he created called 'sslstrip'. See https://www.youtube.com/watch?v=ibF36Yyeehw (beginning at about 8:34). To prevent this type of attack, we now have HTTP Strict Transport Security (HSTS). Sites can include an HSTS header in their response, to inform browsers ...


5

The former is correct, as verified by RFC 2986: PKCS #10: Certification Request Syntax Specification: The process by which a certification request is constructed involves the following steps: 1. A CertificationRequestInfo value containing a subject distinguished name, a subject public key, and optionally a set of attributes ...


4

This sentence is technically correct, but confusing. The CSR contains the public key. The CA does “create” a public key as an intermediate step in generating the certificate, but all it does is to copy it from the CSR, and then embed it in the certificate. It's true that the knowledge of the public key doesn't compromise the private key, but the CA never had ...


3

A Content-Type header is applicable to a response with a body per RFC 2616: When an entity-body is included with a message, the data type of that body is determined via the header fields Content-Type and Content- Encoding. By extension, it's not necessary if there is no response body, as you're describing. It is a SHOULD and not a MUST, so it is RFC-...


2

Read The Java Developer's guide to SSL Certificates Your browsers keep a constantly updated list of root certificates from trusted certificate authorities. Your Java installation also has such a list (referred to as the truststore) but it isn't updated as often (your java truststore will be updated when Java is updated). If you want the new list faster ...


2

You can point a domain name to a private IP address. As a random example, the company I work for has a domain name local.example.com that points to 127.0.0.1. Not that the details matter much, but it uses this for providing MFA to command line tools - the local application will launch a browser window with our SSO/2FA provider, and the return URL for the ...


2

Client certificates are not involved in the creation of the pre-master secret in the first place. This means your threat scenario is not possible. It is also pretty common that no client certificates are used at all in the TLS handshake but only a server certificate, i.e. in many cases no CertificateVerify is even used within the TLS handshake.


2

Under most circumstances, if you connect to the site by HTTPS, and you're sure that the URL is correct (i.e., you're not connecting to a phishing site, like gm4il.com instead of gmail.com), and your browser is not showing you any certificate warnings, then most likely it's safe to login to the site using your password. If you use a password manager, all the ...


2

When the size of the data and mac is equal to a multiple of the block size, a complete block of padding is added. So in effect, there no TLS message that is not padded.


2

HTTP/3 is HTTP over QUIC, which uses UDP packets (instead of HTTP over TCP pakcets). This makes packet loss less costly: instead of stalling all streams in the connection (HTTP/2 supports multiple streams), only the stream with packet lost gets affected. https://blog.cloudflare.com/http-3-vs-http-2/ HTTP/3 uses TLS1.3 over UDP (instead of TLS over TCP). Also,...


1

It is unclear what you are trying to test exactly. But for browsers there is SSLLabs client test. One can also look at the ClientHello (contains all the supported ciphers, curves, hash algorithms ...). ... wanted to know, For anything which needs multiple handshakes (like determining supported protocol versions) one has to somehow instrument the client to ...


1

All the browsers (And the operative systems, like your iOS) includes the public certificates of the Certificate Authorities (CA). These are organisations that validate the ownership of the domains and grant certificates signed by them as a trust authority. By recognising the signature, the browsers knows it comes from a "chain of trust" and shows a ...


1

The PCI DSS concerns itself with the following pieces of data: Except insofar as it might include Customer Name, billing address is not PCI protected data, and there are no PCI requirements around storage, encryption, or lack thereof. Instead, that data is PII, and should be protected in line with whatever PII standards apply to your locality.


1

As explained in the post you've linked to with some comments added by my own: Cloudflare recommends [one] end-to-end encryption of traffic between site visitors and the Cloudflare network and [another one] between Cloudflare’s network and your origin web server. Thus, there are two end-to-end connections here. One from client to Cloudflare and another from ...


1

I don't have an LDAP server to test this with, but if you have openssl 1.1.1, then you should be able to use opensssl s_client to connect to your LDAP server and then proceed with the protocol to upgrade the connection to SSL/TLS using STARTTLS, using a command along the lines of: openssl s_client -starttls ldap -crlf -connect host.domain.tld:port See ...


1

When in doubt, encrypt everything. Now, ask yourself what are you protecting and what from. Since it is a hobby, well... If you use the app.domain.com just for downloading the app, that may render a smaller attack surface, but still there is a risk. I agree with @schroeder in the risk of having a binary replaced with malware. For some time now, Google Chrome ...


1

The easiest method would be to use testssl.sh on a Linux system that can access the site. The command below will give you plenty of information about the security of your TLS implementation, including whether or not it is vulnerable to LOGJAM: ./testssl.sh https://yourSIT-IP.com:yourPort If you just want to test LOGJAM specifically ./testssl.sh https://...


1

This site has a list of various sites that provide PEM bundles, and refers to this git hub project, which provides copies of all the main OS PEM bundles in single file format which can be used by OpenSSL on windows. One can extract the microsoft_windows.pem from provided tar file and use it like so echo | openssl.exe s_client -CAfile microsoft_windows.pem -...


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