# SSL Cert Generation * One of the easiest ways to generate SSL certs is with `certbot` which leverages `letsencrypt` ### Generate your Certs * `certbot certonly --manual -d mydomain.com` ### SSL Overview * This command will generate four files in: ``` /etc/letsencrypt/live/mydomain.com ``` #### privkey,pem * This is the key file, a.k.a. your private key * Sometimes also named as `cert.key` or `mydomain.com.key` #### fullchain.pem * This is your `crt` file * Also sometimes named `mydomain.crt` #### bundle.pem * Contains all the certificates * Would be created with `cat fullchain.pem privkey.pem > bundle.pem` #### cert.pem * This file contains only your certificate * Can only be used by itself if the browser already has the certificate which signed it * May work in testing, don't use in production #### chain.pem * Intermediary signed authority, signed by the root authority * All browsers are guaranteed to have in their pre-built cache. ### Openssl Generate Certs Use `openssl` to generate your own self signed cert ``` openssl req -x509 -sha256 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key -out certificate.crt ``` Generate a new private key and Certificate Signing Request ``` openssl req -out CSR.csr -new -newkey rsa:2048 -nodes -keyout privateKey.key ``` Generate a certificate signing request (CSR) for an existing private key ``` openssl req -out CSR.csr -key privateKey.key -new ``` Generate a certificate signing request based on an existing certificate ``` openssl x509 -x509toreq -in certificate.crt -out CSR.csr -signkey privateKey.key ``` Remove a passphrase from a private key ``` openssl rsa -in privateKey.pem -out newPrivateKey.pem ``` ### Checking Certs You can inspect the cert like this: ``` openssl x509 -in cert.pem -text -noout ``` Check a Certificate Signing Request (CSR) ``` openssl req -text -noout -verify -in CSR.csr ``` Check a private key ``` openssl rsa -in privateKey.key -check ``` Check a certificate ``` openssl x509 -in certificate.crt -text -noout ``` Check a PKCS#12 file (.pfx or .p12) ``` openssl pkcs12 -info -in keyStore.p12 ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://book.ice-wzl.xyz/infrastructure-development/ssl-cert-generation.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.