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
In this case SHA-256. Generate a SSL Key File. Firstly you will need to generate a key file. The example below will generate a 2048 bit key file with a SHA-256 signature. Openssl genrsa -out keyname.key 2048. If you want extra security you could increase the bit lengths. Openssl genrsa -out keyname.key 4096. Each utility is easily broken down via the first argument of openssl. For instance, to generate an RSA key, the command to use will be openssl genpkey. Generate 2048-bit AES-256 Encrypted RSA Private Key.pem. The following command will result in an output file of private.pem in which will be a private RSA key in the PEM format.
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
Since AES-256-GCM requires a 256 bit key I recommend using OpenSSL::Cipher::Cipher.new('aes-256-gcm').randomkey. EDIT Since the value SecureRandom.hex returns in the question was updated to be a hexidecimal encoding the amount of random bits it generates is no longer 192. $ openssl enc -aes-256-cbc -k secret -P -md sha1 salt=E2EE3D7072F8AAF4 key=C94A324B7221AA8A8760DA0717C80256EF4308EC6068B7144AA3BBA4A5F98007 iv =5C7CB13DBDA69B2C091E0D5E95943627 I thought I could just read the key string and base64 decode it to get a 256-bit AES key, but that didn't work because 64 characters turned into a 384-bit byte array after decoding. Act of war high treason cd key code.
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
https://skieygolf.weebly.com/aes-key-generated-after-4-way-handshake-between-client-and-ap.html.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.
![256 256](/uploads/1/2/6/0/126064196/357834607.jpg)
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-----
Generate Random Aes 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.
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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Openssl Generate Aes 256 Key Base64
Other Blog Articles Published by Rietta.com
This post briefly describes how to utilise AES to encrypt and decrypt files with OpenSSL.
![Generate Aes 256 Key Openssl Generate Aes 256 Key Openssl](/uploads/1/2/6/0/126064196/878173013.png)
AES - Advanced Encryption Standard (also known as Rijndael).
OpenSSL - Cryptography and SSL/TLS Toolkit
We’ll walk through the following steps:
- Generate an AES key plus Initialization vector (iv) with
openssl
and - how to encode/decode a file with the generated key/iv pair
Note: AES is a symmetric-key algorithm which means it uses the same key during encryption/decryption. https://skieygolf.weebly.com/anydesk-license-key-mac-generator.html.
Generating key/iv pair
We want to generate a
256
-bit key and use Cipher Block Chaining (CBC).The basic command to use is
openssl enc
plus some options:-P
— Print out the salt, key and IV used, then exit-k <secret>
or-pass pass:<secret>
— to specify the password to use-aes-256-cbc
— the cipher name
Note: We decided to use no salt to keep the example simple.
Issue
openssl enc --help
for more details and options (e.g. other ciphernames, how to specify a salt, …).Encoding
Let's start with encoding
Hello, AES!
contained in the text file message.txt
:Decoding
Decoding is almost the same command line - just an additional
-d
for decrypting:Note: Beware of the line breaks
While working with AES encryption I encountered the situation where the encoder sometimes produces base 64 encoded data with or without line breaks..
Short answer: Yes, use the OpenSSL
-A
option.