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

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.