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.
- Generate A Rsa Key Pair Free
- Generate A Rsa Key Pair On Windows
- Windows Generate Rsa Key Pair
- Generate Rsa Key Pair Ubuntu
Ssh-keygen -t rsa -b 2048. This will create a RSA public/private key pair in the.ssh directory below your account’s home directory. For example: Location: /.ssh (where is the home directory) Private key file name: idrsa; Public key file name: idrsa.pub; cd /.ssh # Change directories to the keys location. Online RSA Key Generator. Key Size 1024 bit. 4096 bit Generate New Keys Async. RSA Encryption Test. Text to encrypt: Encrypt / Decrypt.
The Commands to Run
Generate a 2048 bit RSA Key
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.
Export the RSA Public Key to a File
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
Do Not Run This, it Exports the Private Key
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-----
.Visually Inspect Your Key Files
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 Key Files
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.
The private.pem file looks something like this:
The public key, public.pem, file looks like:
Protecting Your Keys
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.
Generate A Rsa Key Pair Free
Oh, and one last thing.
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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Generate A Rsa Key Pair On Windows
This procedure uses the Java keytool utility to generate a key and save it to a Java keystore.
NOTE:
- The CA you use might have specific options required for creating an HTTPS certificate. Review the instructions provided by the CA before creating your key pair.
- DSA keys used in Reflection Gateway server certificates must be either 2048 or 3072 bits. RSA keys must be between 2048 and 4096 bits.
Windows Generate Rsa Key Pair
To generate a new public/private key pair in a Java keystore
- Use the -genkeypair option to generate a key and save it to a Java keystore (newkeystore.jks in this example). The example shown here prompts you to enter values for items that make up the distinguished name (DN) in the certificate. See the example below to enter these values directly on the command line.
- The keytool prompts you to enter a password and values for the items that make up the distinguished name (DN) in the certificate (name = CN, organizational unit = OU, organization = O, city or locality = L, state or province = S, two letter country code = C). The generated DN will use the value 'Unknown' for any fields you don't specify.
- When you are prompted with “What is your first and last name?'You must enter the DNS name that is used to access the Reflection Gateway server (for example gateway.mycompany.com). This value is used as the CN (Common Name) in the certificate. If the CN in a certificate doesn't match the actual DNS name used to access the server, you will see a certificate warning when you connect to the server.
- When you are prompted with 'What is the two-letter country code for this unit?'You must enter a valid two-letter country code (for example US).
- When you are prompted for a password for the alias, press Enter to use the same password you used for the keystore.
Generate Rsa Key Pair Ubuntu
An alternate option to responding to prompts is to specify the DN value on the command line using the -dname option. For example: