AES

AES implementation in C with Intel intrinsics.

Modes

• AES-CTR-128/192/256
• AES-CBC-128/192/256
• AES-CFB-128/192/256
• AES-OFB-128/192/256
• AES-ECB-128/192/256

Command line utility

Build

make

Usage

Usage: aes.exe -[e|d] [-m mode] [-s size] -i file_in -o file_out [PASSPHRASE]

-e                encrypt
-d                decrypt
-i <file_in>      path to file to encrypt
-o <file_out>     path to encrypted output file
-m <mode>         AES mode: ctr, cbc, ofb, cfb or ecb; default ctr
-s <size>         AES key size: 128, 192 or 256; default 256

Example

# Encrypt in.jpg
$ ./aes.exe -e -i in.jpg -o out.jpg.aes hunter2

# Decrypt in.jpg.aes
$ ./aes.exe -d -i out.jpg.aes -o out.jpg hunter2

# Or enter the passphrase interactively
$ ./aes.exe -e -i in.jpg -o out.jpg.aes
Enter password:
Repeat password:

Api

Build

make lib

Usage

Include the header include/aes.h:

typedef enum KeySize {
    AES_128 = 128,
    AES_192 = 192,
    AES_256 = 256,
} KeySize_t;


typedef enum Mode {
    AES_CTR,
    AES_CBC,
    AES_OFB,
    AES_CFB,
    AES_ECB,
} Mode_t;


/* Encrypt bytes on the heap */
void aes_encrypt(uint8_t ** data, size_t * size, char * passphrase, Mode_t aes_mode, KeySize_t key_size);
/* Decrypt bytes on the heap */
void aes_decrypt(uint8_t ** data, size_t * size, char * passphrase, Mode_t aes_mode, KeySize_t key_size);
/* Encrypt a file */
void aes_encrypt_file(char * filename, char * savename, char * passphrase, Mode_t aes_mode, KeySize_t key_size);
/* Decrypt a file */
void aes_decrypt_file(char * filename, char * savename, char * passphrase, Mode_t aes_mode, KeySize_t key_size);

Api Example

Encrypt/decrypt a file:

#include "aes.h"

int
main(void)
{
    // Encrypt file
    char passphrase[] = "hunter2";	
    
    aes_encrypt_file("in.jpg", "out.jpg.aes", passphrase, AES_CTR, AES_256);
    aes_decrypt_file("out.jpg.aes", "out.jpg", passphrase, AES_CTR, AES_256);
    
    
    // Encrypt data
    size_t size = 10*BLOCKSIZE + 5;
    uint8_t * data = (uint8_t *) malloc(size);
    memset(data, 0xab, size);
    
    aes_encrypt(&data, &size, passphrase, AES_CTR, AES_256);
    aes_decrypt(&data, &size, passphrase, AES_CTR, AES_256);
    
    
    return 0;
}

Benchmarks

• Buffer (in RAM) size = 160 MB
• Averaged over 5 runs
• No threading

AES blocks

	Encrypt	Decrypt
aes_block_128	4790 MB/s	4790 MB/s
aes_block_192	3941 MB/s	4188 MB/s
aes_block_256	3653 MB/s	3320 MB/s

AES modes

	Encrypt	Decrypt
aes_ctr_128	1246 MB/s	1288 MB/s
aes_cbc_128	1610 MB/s	4734 MB/s
aes_cfb_128	1600 MB/s	4420 MB/s
aes_ofb_128	1663 MB/s	1663 MB/s
aes_ecb_128	5063 MB/s	5063 MB/s
aes_ctr_192	1144 MB/s	1143 MB/s
aes_cbc_192	1384 MB/s	4103 MB/s
aes_cfb_192	1377 MB/s	3721 MB/s
aes_ofb_192	1421 MB/s	1423 MB/s
aes_ecb_192	4301 MB/s	4233 MB/s
aes_ctr_256	1024 MB/s	1026 MB/s
aes_cbc_256	1210 MB/s	3404 MB/s
aes_cfb_256	1214 MB/s	3239 MB/s
aes_ofb_256	1240 MB/s	1240 MB/s
aes_ecb_256	3556 MB/s	3509 MB/s