When generating RSA Key, Process Hangs. Sorry if this has been asked before, but I tried to search and didn't come up with much. This has happened on a few servers I have tried to.
This article provides step-by-step instructions for generating a Certificate Signing Request (CSR) in OpenSSL. This is most commonly required for web servers such as Apache HTTP Server and NGINX. If this is not the solution you are looking for, please search for your solution in the search bar above.
GNU/Linux & Mac OS X users:
Open a terminal and browse to a folder where you would like to generate your keypair
Windows Users:
Navigate to your OpenSSL 'bin' directory and open a command prompt in the same location.
Generate a CSR & Private Key:
openssl req -out CSR.csr -new -newkey rsa:2048 -keyout privatekey.key
To generate a 4096-bit CSR you can replace the rsa:2048 syntax with rsa:4096 as shown below.
openssl req -out CSR.csr -new -newkey rsa:4096 -keyout privatekey.key
Note: You will be prompted to enter a password in order to proceed. Keep this password as you will need it to use the Certificate.
Fill out the following fields as prompted:
Note: The following characters can not be accepted: < > ~ ! @ # $ % ^ * / ( ) ?.,&
Field | Example |
---|---|
Country Name | US (2 Letter Code) |
State or Province | New Hampshire (Full State Name) |
Locality | Portsmouth (Full City name) |
Organization | GMO GlobalSign Inc (Entity's Legal Name) |
Organizational Unit | Support (Optional, e.g. a department) |
Common Name | www.globalsign.com (Domain or Entity name) |
You should now have a Private Key (privatekey.key) which should stay on your computer, and a Certificate Signing Request (CSR.csr), which can be submitted to GlobalSign to sign your public key. Each of these files can be viewed in a plain text editor such as Notepad, TextEdit, Vi, Nano, and Notepad++.
While Encrypting a File with a Password from the Command Line using OpenSSLis very useful in its own right, the real power of the OpenSSL library is itsability to support the use of public key cryptograph for encrypting orvalidating data in an unattended manner (where the password is not required toencrypt) is done with public keys.
You can generate a public and private RSA key pair like this:
openssl genrsa -des3 -out private.pem 2048
That generates a 2048-bit RSA key pair, encrypts them with a password you provideand writes them to a file. You need to next extract the public key file. You willuse this, for instance, on your web server to encrypt content so that it canonly be read with the private key.
This is a command that is
openssl rsa -in private.pem -outform PEM -pubout -out public.pem
The -pubout
flag is really important. Be sure to include it.
Next open the public.pem
and ensure that it starts with-----BEGIN PUBLIC KEY-----
. This is how you know that this file is thepublic key of the pair and not a private key.
To check the file from the command line you can use the less
command, like this:
less public.pem
A previous version of the post gave this example in error.
openssl rsa -in private.pem -out private_unencrypted.pem -outform PEM
The error is that the -pubout
was dropped from the end of the command.That changes the meaning of the command from that of exporting the public keyto exporting the private key outside of its encrypted wrapper. Inspecting theoutput file, in this case private_unencrypted.pem
clearly shows that the keyis a RSA private key as it starts with -----BEGIN RSA PRIVATE KEY-----
.
It is important to visually inspect you private and public key files to makesure that they are what you expect. OpenSSL will clearly explain the nature ofthe key block with a -----BEGIN RSA PRIVATE KEY-----
or -----BEGIN PUBLIC KEY-----
.
You can use less to inspect each of your two files in turn:
less private.pem
to verify that it starts with a -----BEGIN RSA PRIVATE KEY-----
less public.pem
to verify that it starts with a -----BEGIN PUBLIC KEY-----
The next section shows a full example of what each key file should look like.
The generated files are base64-encoded encryption keys in plain text format.If you select a password for your private key, its file will be encrypted withyour password. Be sure to remember this password or the key pair becomes useless.
Depending on the nature of the information you will protect, it’s important tokeep the private key backed up and secret. The public key can be distributedanywhere or embedded in your web application scripts, such as in your PHP,Ruby, or other scripts. Again, backup your keys!
Remember, if the key goes away the data encrypted to it is gone. Keeping aprinted copy of the key material in a sealed envelope in a bank safety depositbox is a good way to protect important keys against loss due to fire or harddrive failure.
If you, dear reader, were planning any funny business with the private key that I have just published here. Know that they were made especially for this series of blog posts. I do not use them for anything else.
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How to Generate a Self-Signed Certificate and Private Key using OpenSSL Generating a private key and self-signed certificate can be accomplished in a few simple steps using OpenSSL. We provide here detailed instructions on how to create a private key and self-signed certificate valid for 365 days. Sep 12, 2014 Generate a CSR from an Existing Private Key Use this method if you already have a private key that you would like to use to request a certificate from a CA. This command creates a new CSR (domain.csr) based on an existing private key (domain.key): openssl req -key domain.key -new -out domain.csr. I am using the following command in order to generate a CSR together with a private key by using OpenSSL: openssl req -new -subj '/CN=sample.myhost.com' -out newcsr.csr -nodes -sha512. Generate RSA private key (2048 bit) and a Certificate Signing Request (CSR) with a single command openssl req -new -newkey rsa:2048 -nodes -keyout server.key -out server.csr Convert private key to PEM format openssl rsa -in server.key -outform PEM -out server.pem. Openssl command to generate private key from certificate. Sep 11, 2018 The first thing to do would be to generate a 2048-bit RSA key pair locally. This pair will contain both your private and public key. You can use Java key tool or some other tool, but we will be working with OpenSSL. To generate a public and private key with a certificate signing request (CSR), run the following OpenSSL command.