openssl pem to crt - Shell-Bash

In cryptography, a certificate is a digital document that serves as proof of identity, ownership or authorization. A certificate is signed by a trusted third party, called a certificate authority, and contains information about the entity or person it represents, as well as the public key used to verify digital signatures.

Converting a PEM (Privacy Enhanced Mail) file to a CRT (Certificate file) using OpenSSL is a common task for programmers working with SSL/TLS (Secure Sockets Layer/Transport Layer Security) encryption. This can be done easily using the command line interface in a Shell/Bash terminal.

To convert a PEM file to a CRT file, simply use the following command:

openssl x509 -outform der -in input.pem -out output.crt

This command will convert the PEM file "input.pem" to a CRT file "output.crt".

• openssl is the command for OpenSSL.
• x509 is the command for certificate related functions.
• -outform der specifies the output format to be DER (Distinguished Encoding Rules) format.
• -in input.pem specifies the input file, which is a PEM file.
• -out output.crt specifies the output file, which is a CRT file.

It is important to note that PEM files often contain both the private key and the certificate, and converting only the certificate to a CRT file may result in errors or security issues. Therefore, it is recommended to use a PEM file only when the private key is required, and to use a separate certificate file in all other cases.

In conclusion, converting a PEM file to a CRT file using the OpenSSL command line interface is a simple and important task for anyone working with SSL/TLS encryption.