aes-c

C library for encrypting & decrypting data with AES-128/192/256. (WIP)

Table of Contents

• Install
• Usage
• Contributing
• License

Install

WIP

Usage

Suppose, we need to encrypt data in inbuf with AES-128-CTR & put the encrypted data into outbuf:

/* ... ... are to be replaced with appropriate values. */
const unsigned char inbuf[100] = ... data ...; /* Plain text. */
const unsigned char key[16] = ... key ...; /* Key to encrypt `inbuf` with. */
unsigned char outbuf[100]; /* Destination of encrypted data. */

First, we would initialize the AES context with aes_init function:

AesContext ctx;
aes_init(&ctx, KEY_TYPE_AES128, key);

Then, we would use aes_ctr_xcrypt() to encrypt the data:

/* Set initial IV. Replace with appropriate value. */
const unsigned char iv[16] = ... iv ...;
unsigned char new_iv[16]; /* New IV. */

aes_ctr_xcrypt(&ctx, sizeof outbuf, outbuf, inbuf, iv, new_iv);

API

For more information, see aes.h.

Initialization

Initialize AesContext using aes_init(ctx, key_size, key) where

• ctx is pointer to AesContext
• key_size = 128, 192, 256 for AES-128, AES-192 & AES-256 respectively
• key is pointer to AES key

ECB mode

• For encrypting data using ECB mode, use aes_ecb_encrypt.
• For decrypting data using ECB mode, use aes_ecb_decrypt.

CBC mode

• For encrypting data using CBC mode, use aes_cbc_encrypt.
• For decrypting data using CBC mode, use aes_cbc_decrypt.

CTR mode

For encrypting or decrypting data using CTR mode, use aes_ctr_xcrypt.

Contributing

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, shall be licensed as below, without any additional terms or conditions.

License

© 2021 arnavyc <arnavyc@outlook.com>

Licensed under the BSD Zero Clause License. See LICENSE file in the project root, or https://opensource.org/licenses/0BSD for full license information.

The SPDX license identifier for this project is 0BSD.