This repository showcases a concise implementation of the AES-192 CBC (Cipher Block Chaining) encryption algorithm in C, renowned for its heightened security.
- AES-192 CBC: Implements secure AES-192 CBC encryption mode.
- Fixed Block Size: Enforces a 16-byte fixed block size without padding.
- Compatibility: Encrypted data is interoperable with any AES-192 CBC decryption.
Include "AES_192_CBC.h" before using AES-192 CBC functions.
#include "AES_192_CBC.h"AES_CTX ctx;Initialize the AES context for encryption.
void AES_EncryptInit(AES_CTX *ctx, const uint8_t *key, const uint8_t *iv);ctx: AES context structure.key: Encryption key (24 bytes for AES-192).iv: Initialization vector (16 bytes).
Encrypt a single 16-byte block of data.
void AES_Encrypt(AES_CTX *ctx, const uint8_t *plaintext, uint8_t *ciphertext);ctx: AES context structure.plaintext: Input plaintext block (16 bytes).ciphertext: Output encrypted block (16 bytes).
For multiple blocks, use a loop:
for (unsigned int offset = 0; offset < multiple_block_size; offset += AES_BLOCK_SIZE) {
AES_Encrypt(&ctx, plaintext + offset, ciphertext + offset);
}Initialize the AES context for decryption.
void AES_DecryptInit(AES_CTX *ctx, const uint8_t *key, const uint8_t *iv);ctx: AES context structure.key: Decryption key (24 bytes for AES-192).iv: Initialization vector (16 bytes).
Decrypt a single 16-byte block of data.
void AES_Decrypt(AES_CTX *ctx, const uint8_t *ciphertext, uint8_t *plaintext);ctx: AES context structure.ciphertext: Input encrypted block (16 bytes).plaintext: Output decrypted block (16 bytes).
For multiple blocks, use a loop:
for (unsigned int offset = 0; offset < multiple_block_size; offset += AES_BLOCK_SIZE) {
AES_Decrypt(&ctx, ciphertext + offset, plaintext + offset);
}Free resources associated with the AES context.
void AES_CTX_Free(AES_CTX *ctx);ctx: AES context structure.
#include <stdio.h>
#include "AES_192_CBC.h"
int main() {
AES_CTX ctx;
uint8_t key[AES_KEY_SIZE];
uint8_t iv[AES_BLOCK_SIZE];
uint8_t data[AES_BLOCK_SIZE * 3]; // Example data with three blocks
// Initialization and usage example
memcpy(key, "This is aes key!", AES_KEY_SIZE);
memcpy(iv, "This is an IV123", AES_BLOCK_SIZE);
memcpy(data, "This is test msg123456", AES_BLOCK_SIZE * 3);
printf("Original: ");
for (unsigned int index = 0; index < AES_BLOCK_SIZE * 3; index++) {
printf("%02X", data[index]);
}
printf("\n");
AES_EncryptInit(&ctx, key, iv);
for (unsigned int offset = 0; offset < AES_BLOCK_SIZE * 3; offset += AES_BLOCK_SIZE) {
AES_Encrypt(&ctx, data + offset, data + offset);
}
printf("Encrypted: ");
for (unsigned int index = 0; index < AES_BLOCK_SIZE * 3; index++) {
printf("%02X", data[index]);
}
printf("\n");
AES_DecryptInit(&ctx, key, iv);
for (unsigned int offset = 0; offset < AES_BLOCK_SIZE * 3; offset += AES_BLOCK_SIZE) {
AES_Decrypt(&ctx, data + offset, data + offset);
}
printf("Decrypted: ");
for (unsigned int index = 0; index < AES_BLOCK_SIZE * 3; index++) {
printf("%02X", data[index]);
}
printf("\n");
AES_CTX_Free(&ctx);
return 0;
}Contributions and feedback are welcome! Open issues or submit pull requests.
This AES-192 CBC implementation is provided under the MIT License.