Implement support for private key passphrases

docs/README.md

@@ -1489,6 +1489,21 @@ path of the key file with `--cert-key`:
 (The actually available set of protocols may vary depending on your OpenSSL installation.)
 
 ```bash
+# Specify the vulnerable SSL v3 protocol to talk to an outdated server:
+$ http --ssl=ssl3 https://vulnerable.example.org
+```
+
+### SSL ciphers
+
+You can specify the available ciphers with `--ciphers`.
+It should be a string in the [OpenSSL cipher list format](https://www.openssl.org/docs/man1.1.0/man1/ciphers.html).
+
+```bash
+$ http --ciphers=ECDHE-RSA-AES128-GCM-SHA256 https://pie.dev/get
+```
+
+Note: these cipher strings do not change the negotiated version of SSL or TLS, they only affect the list of available cipher suites.
+
 To see the default cipher string, run `http --help` and see the `--ciphers` section under SSL.
 
 ## Output options