Linux Generate Random Aes Key

1. Create Aes Key
2. Linux Generate Random Aes Keyboard
3. Linux Generate Aes Key
4. C# Aes Generate Key

How do I generate ssh RSA keys under Linux operating systems?
You need to use the ssh-keygen command as follows to generate RSA keys (open terminal and type the following command):
ssh-keygen -t rsa
OR
ssh-keygen
Sample outputs:

An AES-128 expects a key of 128 bit, 16 byte. To generate such a key, use OpenSSL as: openssl rand 16 myaes.key AES-256 expects a key of 256 bit, 32 byte. To generate such a key, use OpenSSL as: openssl rand 16 myaes.key AES-256 expects a key of 256 bit, 32 byte. I've made some improvments on the code from: Csharp-AES-bits-Encryption-Library-with-Salt saltBytes is now the SHA512 of the password. Random IV for each encryption call. ( IV length 16 is added to the encrypted file, removed from file before decryption).

The -t type option specifies the type of key to create. The possible values “rsa” or “dsa” for protocol version 2. The $HOME/.ssh stores the following two files:

• $HOME/.ssh/id_rsa – Your private RSA key
• $HOME/.ssh/id_rsa.pub – Your public RSA key

Please do not share keys file with anyone else. You can upload keys to remote server as follows:
ssh-copy-id userName@server2.nixcraft.net.in
Finally, you can login to remote server as follows:
ssh userName@server2.nixcraft.net.in
scp file.txt userName@server2.nixcraft.net.in:~/data2/

See also:

• Howto Linux / UNIX setup SSH with DSA public key authentication (password less login)
• sshpass: Login To SSH Server / Provide SSH Password Using A Shell Script
• keychain: Set Up Secure Passwordless SSH Access For Backup Scripts

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How to Generate a Symmetric Key byUsing the dd Command

A key is needed to encrypt files and to generate the MAC of a file.The key should be derived from a random pool of numbers.

If your site has a random number generator,use the generator. Otherwise, you can use the dd commandwith the Solaris /dev/urandom device as input. For moreinformation, see the dd(1M) manpage.

1. Determine the key length that your algorithm requires.

   1. Listthe available algorithms.

   2. Determine the key length in bytes to pass to the dd command.

      Divide the minimum and maximum key sizes by 8. When the minimumand maximum key sizes are different, intermediate key sizes are possible.For example, the value 8, 16, or 64 can be passed to the dd commandfor the sha1_hmac and md5_hmac functions.

2. Generate the symmetric key.

   if=file

   Is the input file. For a random key, use the /dev/urandom file.

   of=keyfile

   Is the output file that holds the generated key.

   bs=n

   Is the key size in bytes. For the length in bytes, dividethe key length in bits by 8.

   count=n

   Is the count of the input blocks. The number for n shouldbe 1.

3. Store your key in a protected directory.

   The key fileshould not be readable by anyone but the user.

Example 14–1 Creating a Key for the AES Algorithm

In the following example, a secret key for the AES algorithm is created.The key is also stored for later decryption. AES mechanisms use a 128-bitkey. The key is expressed as 16 bytes in the dd command.

Example 14–2 Creating a Key for the DES Algorithm

Create Aes Key

In the following example, a secret key for the DES algorithm is created.The key is also stored for later decryption. DES mechanisms use a 64-bit key.The key is expressed as 8 bytes in the dd command.

Example 14–3 Creating a Key for the 3DES Algorithm

Linux Generate Random Aes Keyboard

In the following example, a secret key for the 3DES algorithm is created.The key is also stored for later decryption. 3DES mechanisms use a 192-bitkey. The key is expressed as 24 bytes in the dd command.

Example 14–4 Creating a Key for the MD5 Algorithm

Linux Generate Aes Key

In the following example, a secret key for the MD5 algorithm is created.The key is also stored for later decryption. The key is expressed as 64 bytesin the dd command.

C# Aes Generate Key