KnowCardLinux · Apache: TLS & Let's Encrypt
When juggling TLS files, what do the extensions .key, .csr, .pem, and .crt each hold?
Answer locked. Get the free KnowCard app to reveal it — plus spaced-repetition review so it actually sticks.
More in Apache: TLS & Let's Encrypt
A site serves data over plain HTTP and browsers flag it as insecure. What does switching to HTTPS actually add, and why is a CA-issued certificate still needed on top of that?
In TLS, which key encrypts and which decrypts, and how do client and server end up sharing one session key without ever transmitting a private key?
Online banking data is transmitted perfectly tap-proof but arrives at a fraudster's server instead of the bank. Which security property did the encryption fail to provide?
What single command generates a private RSA server key with openssl, and what one permission mistake makes the whole certificate worthless?
Encrypting the server key with a passphrase sounds strictly safer. Why does Apache in practice get an unencrypted copy of the key instead?
You generate a cert with Common Name a-company.com but the site is served at www.a-company.com. What breaks, and what does that tell you about the Common Name field in a CSR?
Start learning today
Free to start — download the app or use it in your browser.