Crypto Key Generate Rsa Command Meaning
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.
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
Generate Rsa Key Pair
openssl rsa -in private.pem -outform PEM -pubout -out public.pem
- That changes the meaning of the command from that of exporting the public key to exporting the private key outside of its encrypted wrapper. Inspecting the output file, in this case privateunencrypted.pem clearly shows that the key is a RSA private key as it starts with -BEGIN RSA PRIVATE KEY-.
- For the private key it may or may not matter to code using the key, but for the public key especially in a CSR or cert the algorithm identifier is visible and can matter. OpenSSL generates a CSR containg a public key which is automatically extracted from the private key, including the AlgId, which is normally copied to a cert where the AlgId in the public key can be significant.
- How to configure SSH on Cisco IOS. (config)#crypto key generate rsa The name for the keys will be: R1.NETWORKLESSONS.LOCAL Choose the size of the key modulus in the range of 360 to 4096 for your General Purpose Keys. Choosing a key modulus greater than 512 may take a few minutes. The command initiated on the VTY line configuration is.
- That changes the meaning of the command from that of exporting the public key to exporting the private key outside of its encrypted wrapper. Inspecting the output file, in this case privateunencrypted.pem clearly shows that the key is a RSA private key as it starts with -BEGIN RSA PRIVATE KEY-.
Crypto key generate rsa modulus 1024 ip domain-name domain-name ip ssh version 2 ip ssh time-out 120 ip ssh authentication-retries 3 line vty 0 4 transport input telnet ssh end. Oct 25, 2019 Generate the key pair! Router(config)# crypto key generate rsa general-purpose label mycs exportable The name for the keys will be: mycs Choose the size of the key modulus in the range of 360 to 2048 for your General Purpose Keys. Choosing a key modulus greater than 512 may take a few minutes. The crypto key generates RSA command is something that will be dependent on the IP domain name commands and the hostname. The crypto command can be used in order to generate a key pair which will have a private and public RSA key.
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.pemto verify that it starts with a-----BEGIN RSA PRIVATE KEY-----less public.pemto 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:
Generate Rsa Key Command
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.
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.
Generate A Rsa Crypto Key
Found an issue?
Cisco Crypto Key Generate Rsa
Rietta plans, develops, and maintains applications.
Learn more about our services or drop us your email and we'll e-mail you back.