openssl-genrsa: Generate RSA Private Key

Overview

openssl-genrsa is used to generate an RSA private key. The generated key is output in PEM format and can be encrypted for storage if needed. The bit length of the key can be specified to adjust its security strength.

Key Features

Generates RSA private keys
Outputs in PEM format
Key bit length can be specified (adjusts security strength)
Supports encryption of generated keys

Key Options

These are the main options used with the openssl-genrsa command.

Output and Encryption

Key Attributes

Generated command:

Try combining the commands.

Description:

`openssl-genrsa` Executes the command.

Combine the above options to virtually execute commands with AI.

Usage Examples

Various examples of generating RSA private keys using the openssl-genrsa command.

Generate Basic RSA Private Key (2048-bit)

openssl genrsa -out private.key 2048

Generates a 2048-bit RSA private key and saves it to the file 'private.key'.

Generate Encrypted RSA Private Key (AES256)

openssl genrsa -aes256 -out encrypted_private.key 4096

Generates a 4096-bit RSA private key with AES256 encryption, which will prompt for a password.

Generate Key Using Public Exponent 3

openssl genrsa -3 -out private_exp3.key 2048

Generates a 2048-bit RSA private key with the public exponent set to 3.

Installation

openssl-genrsa is part of the OpenSSL package. While OpenSSL is pre-installed on most Linux distributions, you can install it using the following commands if it's not present.

Debian/Ubuntu

sudo apt update && sudo apt install openssl

Installs OpenSSL using the APT package manager.

CentOS/RHEL/Fedora

sudo yum install openssl

Installs OpenSSL using the YUM or DNF package manager.

Arch Linux

sudo pacman -S openssl

Installs OpenSSL using the Pacman package manager.

Tips & Precautions

Points to consider and security tips when generating RSA private keys.

Recommended Key Length

According to current security standards, it is recommended to use a key length of at least 2048 bits. 4096 bits offer higher security but may result in longer computation times.

Minimum 2048 bits recommended
4096 bits provide higher security (consider performance)

Private Key Security

Generated private keys are highly sensitive information and must be protected rigorously. To prevent unauthorized access, set appropriate file permissions and, if possible, encrypt them for storage.

Set file permissions to 600 (rw-------) (e.g., `chmod 600 private.key`)
Encrypt and save the key using options like `-aes256` during generation
Back up in a secure location

Public Exponent Selection

The default public exponent `-f4` (65537) is suitable for most cases and does not pose security issues. Unless there's a specific reason, it's best to use the default value.

Default `-f4` (65537) is recommended
No change needed unless for specific compatibility issues