Sep 11, 2018 Use a text editor to open the file, and you will see the private key at the top of the list in the standard format:-BEGIN RSA PRIVATE KEY- (Encrypted Text Block) -END RSA PRIVATE KEY-Copy the private key, including the “BEGIN” and “END” tags, and paste it into a new text file. Save the text file as YourDomainName.key. I am responsible for maintaining two Debian servers. Every time I have to do anything with security certificates, I Google for tutorials and beat away. How can I find the private key for my SSL certificate. If you just got an issued SSL certificate and are having a hard time finding the corresponding private key, this article can help you to find that one and only key for your certificate.
Common OpenSSL Commands with Keys and Certificates
Generate RSA private key with certificate in a single command
Type the following command in an open terminal window on your computer to generate your private key using SSL: $ openssl genrsa -out /path/to/wwwservercom.key 2048. This will invoke OpenSSL, instruct it to generate an RSA private key using the DES3 cipher, and send it as an output to a file in the same directory where you ran the command. The private key however is stored on the machine that generated the CSR (presumably the server requiring the cert, but not necessarily) and is NOT included in the contents of the CSR, and may not be derived from the CSR. It is kept private. In general terms, the server generating the CSR generates a key pair (public and private).
Generate Certificate Signing Request (CSR) from private key with passphrase
Generate RSA private key (2048 bit)
Generate a Certificate Signing Request (CSR)
Generate RSA private key (2048 bit) and a Certificate Signing Request (CSR) with a single command
Convert private key to PEM format
Generate a self-signed certificate that is valid for a year with sha256 hash
View details of a RSA private key
View details of a CSR
View details of a Certificate
View details of a Certificate in DER format
Openssl Generate Private Key From Pem File
Convert a DER file (.crt .cer .der) to PEM
Convert a PEM file to DER
Introduction
A Certificate Signing Request (CSR) is the first step in setting up an SSL Certificate on your website. SSL certificates are provided by Certificate Authorities (CA), which require a Certificate Signing Request (CSR).
This guide will instruct you on how to generate a Certificate Signing Request using OpenSSL.
Access to a user account with root or sudo privileges
A command line/terminal window
If you’re working on a remote server, an established SSH connection to the server
OpenSSL needs to be installed on your system to generate the key
A text editor, such as nano, to view your key
Open a terminal window. Use your SSH connection to log into your remote server.
Note: If you are working locally, you don’t need an SSH connection. Also, most Linux systems will launch a terminal window by pressing Ctrl-Alt-T or Ctrl-Alt-F1.
Step 2: Create an RSA Private Key and CSR
It is advised to issue a new private key each time you generate a CSR. Hence, the steps below instruct on how to generate both the private key and the CSR.
Make sure to replace your_domain with the actual domain you’re generating a CSR for.
The commands are broken out as follows:
openssl – activates the OpenSSL software
req – indicates that we want a CSR
–new –newkey – generate a new key
rsa:2048 – generate a 2048-bit RSA mathematical key
–nodes – no DES, meaning do not encrypt the private key in a PKCS#12 file
–keyout – indicates the domain you’re generating a key for
–out – specifies the name of the file your CSR will be saved as
Note: Use 2048-bit key pairs. The 4096-bit key pairs are more secure, however, they require a lot more server resources.
Your system should launch a text-based questionnaire for you to fill out.
Enter your information in the fields as follows:
Country Name – use a 2-letter country code (US for the United States)
State – the state in which the domain owner is incorporated
Locality – the city in which the domain owner is incorporated
Organization name – the legal entity that owns the domain
Organizational unit name – the name of the department or group in your organization that deals with certificates
Common name – typically the fully qualified domain name (FQDN), i.e. what the users type in a web browser to navigate to your website
Email address – the webmaster’s email address
Challenge password – an optional password for your key pair
Please take into account that Organization Name and Unit Name must not contain the following characters:
< > ~ ! @ # $ % ^ * / ( ) ?.,&
How To Create Private Key File Openssl
Once the software finishes, you should be able to find the CSR file in your working directory.
You can also enter the following:
The system should list out all certificate signing requests on the system. The one that matches the domain name you provided in Step 2 appended with the .csr extension is the one you need to look into.
Step 5: Submit the CSR as Part of Your SSL Request
You can open the .csr file in a text editor to find the alphanumeric code that was generated.
Enter the following command:
This text can be copied and pasted into a submittal form to request your SSL certificate from a Certificate Authority.
Make sure you copy the entire text. Some CAs may allow you to simply upload the .csr file you generated. Below is an example of a CSR.
You needn’t send the private key to the CA. Once you get your SSL certificate, the private key on the server will bind with it to encrypt communication.
Now you know how to generate an OpenSSL certificate signing request. Before submitting the CSR to a certificate authority, we recommend verifying the information it holds. Use one of the widely available online CSR decoders.
SSL is a crucial protocol for securing traffic between a website and its visitors. It helps to protect sensitive information online, such as credit card data.