aschurman / crypto Goto Github PK

Let's implement some cryptographic algorithms for fun! This project is just for fun. Obviously don't use any of this code in any security-critical application!

For now, AES-128, AES-192, and AES-256 are implemented; ECB and CBC modes are supported.

The supplied makefile is for the Windows NMAKE utility. Running nmake will produce aes.exe.

Run aes.exe from the command line:

aes.exe [options] inputFile outputFile

Required options include:

• -k [key file] Provides the file containing AES key. The file must contain exactly 16, 24, or 32 bytes.
• -e or -d Indicates whether to encrypt (-e) or decrypt (-d) the input file.

Optional arguments include:

• -m [mode] Indicates what mode of operation to use for AES encryption. Valid modes are cbc and ecb, with the default being cbc. The mode is specified in the header of an encrypted file, so this option is ignored when -d is specified.
• -f Force. Overwrites output file if it already exists.
• -v Verbose. More about the status of the encryption/decryption will be written to cout.
• -t Test. Instead of encrypting/decrypting a file, run tests to verify that aes.exe is working correctly.

For example, to encrypt a file secrets.txt to a file encryptedSecrets.bin, using an AES key in the file key.bin, run:

aes.exe -e -k key.bin secrets.txt encryptedSecrets.bin

Before running the tests with aes.exe -t, the test files must be generated in the testFiles folder. This folder contains vectors.txt, which contains AES test vectors published by NIST. To expand these test vectors into files used by aes.exe -t, run maketests.bat in the testFiles folder.

As my leisure time permits, here are my future tasks for this project:

• Implement other AES modes of operation.
• Derive AES keys from passwords rather than using a key read from a file.
• Implement other cryptographic algorithms.