openssl-x509:tldr:95826

The given command is using OpenSSL, a command-line tool cryptography toolkit, to perform a specific operation on an X.509 certificate.

Let's break down the command, considering the provided variables:

1. ${certificate_file}: This is a placeholder representing the path or location of the input X.509 certificate file. You need to replace it with the actual file path.

2. ${output_file}: Similarly, it represents the path or location of the output file where the public key extracted from the X.509 certificate will be stored. You should replace it with the desired output file path.

Now let's understand the individual components of the command:

• openssl: This is the command itself, which invokes the OpenSSL toolkit.

• x509: This is a subcommand of OpenSSL that deals with X.509 certificates. In this case, we want to perform operations related to a certificate.

• -in ${certificate_file}: This option specifies the input file containing the X.509 certificate that we want to work with. The ${certificate_file} variable should be replaced with the actual file path.

• -noout: This option instructs OpenSSL not to output any additional information by suppressing the normal output of the certificate details.

• -pubkey: This option tells OpenSSL to extract the public key from the X.509 certificate.

• -out ${output_file}: This option specifies the output file where the extracted public key should be saved. The ${output_file} variable should be replaced with the desired output file path.

Overall, the command takes an X.509 certificate as input, extracts the public key from it, and saves the public key into the specified output file.