Question

(3) Using OpenSSL from the command line interface

a. Create a text file with some input and encrypt it using AES-128 CBC AES-256 CTR DES

b. Create a 2048 bit RSA public and private key

Answer 1

a. Create a text file with some input and encrypt it using AES-128 CBC AES-256 CTR DES

A text file is created with file name message.txt

The command syntax to encrypt file specifying the encryption algorithm is:

$ openssl <Encryption Algorithm> -e -in <InputFile> -out <OutPutFileName>

The command syntax to encrypt file specifying the encryption algorithm is:

$ openssl <Encryption Algorithm> -d -in <EncryptedFile> -out <OutPutFileName>

Encrypt the file using AES-128 CBC is

$ openssl aes-128-cbc -e -in message.txt -out message.txt.enc

Encrypt the file using AES-256 CTR is

$ openssl aes-256-ctr -e -in message.txt -out message.txt.enc

Encrypt the file using DES is

$ openssl des -e -in message.txt -out message.txt.enc

The output of the encrypted files are verified by decrypting the files.

Sample Output:

b. Create a 2048 bit RSA public and private key

Command to generate private key is:

$ openssl genrsa -out PrivateKey.key 2048

We have to extract the public key from the private key. The command is

$ openssl rsa -in PrivateKey.key -out PublicKey.key -pubout -outform PEM

-outform : output format to be spcified

Sample Output: