mirror of https://github.com/kokke/tiny-AES-c
adding Key Expansion for AES192 and AES256
This commit is contained in:
Matteo Brichese
parent
200274e385
commit
c26fb6a5ec
91
aes.c
91
aes.c
|
|
@ -37,18 +37,28 @@ NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0)
|
|||
#include <string.h> // CBC mode, for memset
|
||||
#include "aes.h"
|
||||
|
||||
|
||||
/*****************************************************************************/
|
||||
/* Defines: */
|
||||
/*****************************************************************************/
|
||||
// The number of columns comprising a state in AES. This is a constant in AES. Value=4
|
||||
#define Nb 4
|
||||
// The number of 32 bit words in a key.
|
||||
#define Nk 4
|
||||
// Key length in bytes [128 bit]
|
||||
#define KEYLEN 16
|
||||
// The number of rounds in AES Cipher.
|
||||
#define Nr 10
|
||||
|
||||
#ifdef AES256
|
||||
#define Nk 8
|
||||
#define KEYLEN 32
|
||||
#define Nr 14
|
||||
#define keyExpSize 240
|
||||
#elif defined(AES192)
|
||||
#define Nk 6
|
||||
#define KEYLEN 24
|
||||
#define Nr 12
|
||||
#define keyExpSize 208
|
||||
#else
|
||||
#define Nk 4 // The number of 32 bit words in a key.
|
||||
#define KEYLEN 16 // Key length in bytes
|
||||
#define Nr 10 // The number of rounds in AES Cipher.
|
||||
#define keyExpSize 176
|
||||
#endif
|
||||
|
||||
// jcallan@github points out that declaring Multiply as a function
|
||||
// reduces code size considerably with the Keil ARM compiler.
|
||||
|
|
@ -66,7 +76,7 @@ typedef uint8_t state_t[4][4];
|
|||
static state_t* state;
|
||||
|
||||
// The array that stores the round keys.
|
||||
static uint8_t RoundKey[176];
|
||||
static uint8_t RoundKey[keyExpSize];
|
||||
|
||||
// The Key input to the AES Program
|
||||
static const uint8_t* Key;
|
||||
|
|
@ -116,27 +126,25 @@ static const uint8_t rsbox[256] =
|
|||
0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
|
||||
0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d };
|
||||
|
||||
|
||||
// The round constant word array, Rcon[i], contains the values given by
|
||||
// x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
|
||||
// Note that i starts at 1, not 0).
|
||||
static const uint8_t Rcon[255] = {
|
||||
0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
|
||||
0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
|
||||
0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
|
||||
0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
|
||||
0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
|
||||
0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
|
||||
0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
|
||||
0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
|
||||
0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
|
||||
0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
|
||||
0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
|
||||
0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
|
||||
0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
|
||||
0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
|
||||
0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
|
||||
0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb };
|
||||
static const uint8_t Rcon[256] = {
|
||||
0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
|
||||
0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
|
||||
0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
|
||||
0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
|
||||
0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
|
||||
0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
|
||||
0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
|
||||
0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
|
||||
0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
|
||||
0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
|
||||
0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
|
||||
0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
|
||||
0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
|
||||
0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
|
||||
0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
|
||||
0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d };
|
||||
|
||||
|
||||
/*****************************************************************************/
|
||||
|
|
@ -155,7 +163,7 @@ static uint8_t getSBoxInvert(uint8_t num)
|
|||
// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
|
||||
static void KeyExpansion(void)
|
||||
{
|
||||
uint32_t i, j, k;
|
||||
uint32_t i, k;
|
||||
uint8_t tempa[4]; // Used for the column/row operations
|
||||
|
||||
// The first round key is the key itself.
|
||||
|
|
@ -168,15 +176,19 @@ static void KeyExpansion(void)
|
|||
}
|
||||
|
||||
// All other round keys are found from the previous round keys.
|
||||
for(; (i < (Nb * (Nr + 1))); ++i)
|
||||
//i == Nk
|
||||
for(i = Nk; i < Nb * (Nr + 1); ++i)
|
||||
{
|
||||
for(j = 0; j < 4; ++j)
|
||||
{
|
||||
tempa[j]=RoundKey[(i-1) * 4 + j];
|
||||
tempa[0]=RoundKey[(i-1) * 4 + 0];
|
||||
tempa[1]=RoundKey[(i-1) * 4 + 1];
|
||||
tempa[2]=RoundKey[(i-1) * 4 + 2];
|
||||
tempa[3]=RoundKey[(i-1) * 4 + 3];
|
||||
}
|
||||
|
||||
if (i % Nk == 0)
|
||||
{
|
||||
// This function rotates the 4 bytes in a word to the left once.
|
||||
// This function shifts the 4 bytes in a word to the left once.
|
||||
// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
|
||||
|
||||
// Function RotWord()
|
||||
|
|
@ -201,7 +213,8 @@ static void KeyExpansion(void)
|
|||
|
||||
tempa[0] = tempa[0] ^ Rcon[i/Nk];
|
||||
}
|
||||
else if (Nk > 6 && i % Nk == 4)
|
||||
#ifdef AES256
|
||||
if (i % Nk == 4)
|
||||
{
|
||||
// Function Subword()
|
||||
{
|
||||
|
|
@ -211,6 +224,7 @@ static void KeyExpansion(void)
|
|||
tempa[3] = getSBoxValue(tempa[3]);
|
||||
}
|
||||
}
|
||||
#endif
|
||||
RoundKey[i * 4 + 0] = RoundKey[(i - Nk) * 4 + 0] ^ tempa[0];
|
||||
RoundKey[i * 4 + 1] = RoundKey[(i - Nk) * 4 + 1] ^ tempa[1];
|
||||
RoundKey[i * 4 + 2] = RoundKey[(i - Nk) * 4 + 2] ^ tempa[2];
|
||||
|
|
@ -451,7 +465,7 @@ static void BlockCopy(uint8_t* output, const uint8_t* input)
|
|||
#if defined(ECB) && ECB
|
||||
|
||||
|
||||
void AES128_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* output)
|
||||
void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* output)
|
||||
{
|
||||
// Copy input to output, and work in-memory on output
|
||||
BlockCopy(output, input);
|
||||
|
|
@ -464,7 +478,7 @@ void AES128_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* outpu
|
|||
Cipher();
|
||||
}
|
||||
|
||||
void AES128_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output)
|
||||
void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output)
|
||||
{
|
||||
// Copy input to output, and work in-memory on output
|
||||
BlockCopy(output, input);
|
||||
|
|
@ -496,7 +510,7 @@ static void XorWithIv(uint8_t* buf)
|
|||
}
|
||||
}
|
||||
|
||||
void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
|
||||
void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
|
||||
{
|
||||
uintptr_t i;
|
||||
uint8_t remainders = length % KEYLEN; /* Remaining bytes in the last non-full block */
|
||||
|
|
@ -536,7 +550,7 @@ void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length,
|
|||
}
|
||||
}
|
||||
|
||||
void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
|
||||
void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
|
||||
{
|
||||
uintptr_t i;
|
||||
uint8_t remainders = length % KEYLEN; /* Remaining bytes in the last non-full block */
|
||||
|
|
@ -577,7 +591,4 @@ void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length,
|
|||
}
|
||||
}
|
||||
|
||||
|
||||
#endif // #if defined(CBC) && CBC
|
||||
|
||||
|
||||
|
|
|
|||
10
aes.h
10
aes.h
|
|
@ -19,22 +19,20 @@
|
|||
#endif
|
||||
|
||||
|
||||
|
||||
#if defined(ECB) && ECB
|
||||
|
||||
void AES128_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t *output);
|
||||
void AES128_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output);
|
||||
void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t *output);
|
||||
void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output);
|
||||
|
||||
#endif // #if defined(ECB) && ECB
|
||||
|
||||
|
||||
#if defined(CBC) && CBC
|
||||
|
||||
void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
|
||||
void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
|
||||
void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
|
||||
void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);
|
||||
|
||||
#endif // #if defined(CBC) && CBC
|
||||
|
||||
|
||||
|
||||
#endif //_AES_H_
|
||||
|
|
|
|||
Loading…
Reference in New Issue