mirror of
https://github.com/jb55/nostril.git
synced 2024-11-24 08:59:08 -05:00
92 lines
2.7 KiB
C
92 lines
2.7 KiB
C
#ifndef _AES_H_
|
|
#define _AES_H_
|
|
|
|
#include <stdint.h>
|
|
#include <stddef.h>
|
|
|
|
// #define the macros below to 1/0 to enable/disable the mode of operation.
|
|
//
|
|
// CBC enables AES encryption in CBC-mode of operation.
|
|
// CTR enables encryption in counter-mode.
|
|
// ECB enables the basic ECB 16-byte block algorithm. All can be enabled simultaneously.
|
|
|
|
// The #ifndef-guard allows it to be configured before #include'ing or at compile time.
|
|
#ifndef CBC
|
|
#define CBC 1
|
|
#endif
|
|
|
|
#ifndef ECB
|
|
#define ECB 0
|
|
#endif
|
|
|
|
#ifndef CTR
|
|
#define CTR 0
|
|
#endif
|
|
|
|
|
|
//#define AES128 1
|
|
//#define AES192 1
|
|
#define AES256 1
|
|
|
|
#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only
|
|
|
|
#if defined(AES256) && (AES256 == 1)
|
|
#define AES_KEYLEN 32
|
|
#define AES_keyExpSize 240
|
|
#elif defined(AES192) && (AES192 == 1)
|
|
#define AES_KEYLEN 24
|
|
#define AES_keyExpSize 208
|
|
#else
|
|
#define AES_KEYLEN 16 // Key length in bytes
|
|
#define AES_keyExpSize 176
|
|
#endif
|
|
|
|
struct AES_ctx
|
|
{
|
|
uint8_t RoundKey[AES_keyExpSize];
|
|
#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
|
|
uint8_t Iv[AES_BLOCKLEN];
|
|
#endif
|
|
};
|
|
|
|
void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key);
|
|
#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
|
|
void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);
|
|
void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
|
|
#endif
|
|
|
|
#if defined(ECB) && (ECB == 1)
|
|
// buffer size is exactly AES_BLOCKLEN bytes;
|
|
// you need only AES_init_ctx as IV is not used in ECB
|
|
// NB: ECB is considered insecure for most uses
|
|
void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf);
|
|
void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf);
|
|
|
|
#endif // #if defined(ECB) && (ECB == !)
|
|
|
|
|
|
#if defined(CBC) && (CBC == 1)
|
|
// buffer size MUST be mutile of AES_BLOCKLEN;
|
|
// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
|
|
// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv()
|
|
// no IV should ever be reused with the same key
|
|
void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
|
|
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
|
|
|
|
#endif // #if defined(CBC) && (CBC == 1)
|
|
|
|
|
|
#if defined(CTR) && (CTR == 1)
|
|
|
|
// Same function for encrypting as for decrypting.
|
|
// IV is incremented for every block, and used after encryption as XOR-compliment for output
|
|
// Suggesting https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
|
|
// NOTES: you need to set IV in ctx with AES_init_ctx_iv() or AES_ctx_set_iv()
|
|
// no IV should ever be reused with the same key
|
|
void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
|
|
|
|
#endif // #if defined(CTR) && (CTR == 1)
|
|
|
|
|
|
#endif // _AES_H_
|