Openssl Command Generate Symmetric Key
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.
- Openssl Command Generate Symmetric Keys
- Openssl Symmetric Key Generation
- Openssl Generate Rsa Private Key
- Openssl Commands For Creating Private Key
- Openssl Generate Key From Csr
- Openssl Command To Generate Symmetric Key
In it's simplest form, the command to generate a key based on the same curve as in the example above looks like this: $ openssl genpkey -algorithm EC -pkeyopt ecparamgencurve:P-256 This command will result in the generated key being printed to the terminal's output. To illustrate how OpenSSL manages public key algorithms we are going to use the famous RSA algorithm. Other algorithms exist of course, but the principle remains the same. 3.1 Key generation. First we need to generate a pair of public/private key. In this example we create a pair of RSA key. OpenSSL is a C library that implements the main cryptographic operations like symmetric encryption, public-key encryption, digital signature, hash functions and so on. OpenSSL also implements obviously the famous Secure Socket Layer (SSL) protocol. OpenSSL is avaible for a wide variety of platforms. Use the following command to generate the random key: openssl rand -hex 64 -out key.bin Do this every time you encrypt a file. Use a new key every time! The key format is HEX because the base64 format adds newlines. The -pass argument later on only takes the first line of the file, so the full key is not used. (Thanks Ken Larson for pointing this to me).
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 Command Generate Symmetric Keys
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-----.
Openssl Symmetric Key Generation
Windows 7 enterprise activation key generator download. 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:
Protecting Your Keys
Openssl Generate Rsa Private Key
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.
Openssl Commands For Creating Private Key
Found an issue?
Rietta plans, develops, and maintains applications.
Openssl Generate Key From Csr
Learn more about our services or drop us your email and we'll e-mail you back.