In this assignment, you will implement encrypted communications between two part
ID: 3745203 • Letter: I
Question
In this assignment, you will implement encrypted communications between two parties, Alice and Bob, and evaluate the performance of AES and RSA under different parameters. For simplicity, Alice and Bob will be simulated by two programs running on the same computer. When Alice sends a message to Bob, she writes the message to a file. Bob receives the message through reading from the file.
Part 1: Implement encryption and decryption using AES with 192-bit key. Assume that Alice and Bob already have a shared secret key k (e.g., they can read the key from the same file). Alice encrypts an 18-byte message m (the message is manually input from command line), and writes the ciphetext into a file named ctext. Bob reads the ciphertext from the file, decrypts it, and prints the message m. The encryption should use the CBC mode
Explanation / Answer
Small and portable implementation of the AES ECB, CTR and CBC encryption algorithms coded in C.
You can override the default key-size of 128 bit with 192 or 256 bit by defining the symbols AES192 or AES256 in aes.h.
The API is very simple and looks like this (I am using C99 <stdint.h>-style annotated types):
/* Initialize context calling one of: */
void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key);
void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);
/* ... or reset IV at random point: */
void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
/* Then start encrypting and decrypting with the functions below: */
void AES_ECB_encrypt(struct AES_ctx* ctx, uint8_t* buf);
void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf);
void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length);
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length);
/* Same function for encrypting as for decrypting in CTR mode */
void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length);
Note:
No padding is provided so for CBC and ECB all buffers should be multiples of 16 bytes. For padding PKCS7 is recommendable.
You can choose to use any or all of the modes-of-operations, by defining the symbols CBC, CTR or ECB. See the header file for clarification.
C++ users should #include aes.hpp instead of aes.h
There is no built-in error checking or protection from out-of-bounds memory access errors as a result of malicious input.
You can use ARM GCC compiler.
aes.c
/*
This is an implementation of the AES algorithm, specifically ECB, CTR and CBC mode.
Block size can be chosen in aes.h - available choices are AES128, AES192, AES256.
----------
plain-text:
6bc1bee22e409f96e93d7e117393172a
ae2d8a571e03ac9c9eb76fac45af8e51
30c81c46a35ce411e5fbc1191a0a52ef
f69f2445df4f9b17ad2b417be66c3710
key:
2b7e151628aed2a6abf7158809cf4f3c
resulting cipher
3ad77bb40d7a3660a89ecaf32466ef97
f5d3d58503b9699de785895a96fdbaaf
43b1cd7f598ece23881b00e3ed030688
7b0c785e27e8ad3f8223207104725dd4
NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0)
You should pad the end of the string with zeros if this is not the case.
For AES192/256 the key size is proportionally larger.
*/
/* Includes: */
/*****************************************************************************/
#include <stdint.h>
#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
#if defined(AES256) && (AES256 == 1)
#define Nk 8
#define Nr 14
#elif defined(AES192) && (AES192 == 1)
#define Nk 6
#define Nr 12
#else
#define Nk 4 // The number of 32 bit words in a key.
#define Nr 10 // The number of rounds in AES Cipher.
#endif
/*****************************************************************************/
/* Private variables: */
/*****************************************************************************/
// state - array holding the intermediate results during decryption.
typedef uint8_t state_t[4][4];
// The lookup-tables are marked const so they can be placed in read-only storage instead of RAM
// The numbers below can be computed dynamically trading ROM for RAM -
// This can be useful in (embedded) bootloader applications, where ROM is often limited.
static const uint8_t sbox[256] = {
//0 1 2 3 4 5 6 7 8 9 A B C D E F
0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
static const uint8_t rsbox[256] = {
0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
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 the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
static const uint8_t Rcon[11] = {
0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };
/*****************************************************************************/
/* Private functions: */
/*****************************************************************************/
/*
static uint8_t getSBoxValue(uint8_t num)
{
return sbox[num];
}
*/
#define getSBoxValue(num) (sbox[(num)])
/*
static uint8_t getSBoxInvert(uint8_t num)
{
return rsbox[num];
}
*/
#define getSBoxInvert(num) (rsbox[(num)])
// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
static void KeyExpansion(uint8_t* RoundKey, const uint8_t* Key)
{
unsigned i, j, k;
uint8_t tempa[4]; // Used for the column/row operations
// The first round key is the key itself.
for (i = 0; i < Nk; ++i)
{
RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
}
// All other round keys are found from the previous round keys.
for (i = Nk; i < Nb * (Nr + 1); ++i)
{
{
k = (i - 1) * 4;
tempa[0]=RoundKey[k + 0];
tempa[1]=RoundKey[k + 1];
tempa[2]=RoundKey[k + 2];
tempa[3]=RoundKey[k + 3];
}
if (i % Nk == 0)
{
// This function shifts the 4 bytes in a word to the left once.
// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
// Function RotWord()
{
k = tempa[0];
tempa[0] = tempa[1];
tempa[1] = tempa[2];
tempa[2] = tempa[3];
tempa[3] = k;
}
// SubWord() is a function that takes a four-byte input word and
// applies the S-box to each of the four bytes to produce an output word.
// Function Subword()
{
tempa[0] = getSBoxValue(tempa[0]);
tempa[1] = getSBoxValue(tempa[1]);
tempa[2] = getSBoxValue(tempa[2]);
tempa[3] = getSBoxValue(tempa[3]);
}
tempa[0] = tempa[0] ^ Rcon[i/Nk];
}
#if defined(AES256) && (AES256 == 1)
if (i % Nk == 4)
{
// Function Subword()
{
tempa[0] = getSBoxValue(tempa[0]);
tempa[1] = getSBoxValue(tempa[1]);
tempa[2] = getSBoxValue(tempa[2]);
tempa[3] = getSBoxValue(tempa[3]);
}
}
#endif
j = i * 4; k=(i - Nk) * 4;
RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0];
RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1];
RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2];
RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3];
}
}
void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key)
{
KeyExpansion(ctx->RoundKey, 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)
{
KeyExpansion(ctx->RoundKey, key);
memcpy (ctx->Iv, iv, AES_BLOCKLEN);
}
void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv)
{
memcpy (ctx->Iv, iv, AES_BLOCKLEN);
}
#endif
// This function adds the round key to state.
// The round key is added to the state by an XOR function.
static void AddRoundKey(uint8_t round,state_t* state,uint8_t* RoundKey)
{
uint8_t i,j;
for (i = 0; i < 4; ++i)
{
for (j = 0; j < 4; ++j)
{
(*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j];
}
}
}
// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
static void SubBytes(state_t* state)
{
uint8_t i, j;
for (i = 0; i < 4; ++i)
{
for (j = 0; j < 4; ++j)
{
(*state)[j][i] = getSBoxValue((*state)[j][i]);
}
}
}
// The ShiftRows() function shifts the rows in the state to the left.
// Each row is shifted with different offset.
// Offset = Row number. So the first row is not shifted.
static void ShiftRows(state_t* state)
{
uint8_t temp;
// Rotate first row 1 columns to left
temp = (*state)[0][1];
(*state)[0][1] = (*state)[1][1];
(*state)[1][1] = (*state)[2][1];
(*state)[2][1] = (*state)[3][1];
(*state)[3][1] = temp;
// Rotate second row 2 columns to left
temp = (*state)[0][2];
(*state)[0][2] = (*state)[2][2];
(*state)[2][2] = temp;
temp = (*state)[1][2];
(*state)[1][2] = (*state)[3][2];
(*state)[3][2] = temp;
// Rotate third row 3 columns to left
temp = (*state)[0][3];
(*state)[0][3] = (*state)[3][3];
(*state)[3][3] = (*state)[2][3];
(*state)[2][3] = (*state)[1][3];
(*state)[1][3] = temp;
}
static uint8_t xtime(uint8_t x)
{
return ((x<<1) ^ (((x>>7) & 1) * 0x1b));
}
// MixColumns function mixes the columns of the state matrix
static void MixColumns(state_t* state)
{
uint8_t i;
uint8_t Tmp, Tm, t;
for (i = 0; i < 4; ++i)
{
t = (*state)[i][0];
Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3] ;
Tm = (*state)[i][0] ^ (*state)[i][1] ; Tm = xtime(Tm); (*state)[i][0] ^= Tm ^ Tmp ;
Tm = (*state)[i][1] ^ (*state)[i][2] ; Tm = xtime(Tm); (*state)[i][1] ^= Tm ^ Tmp ;
Tm = (*state)[i][2] ^ (*state)[i][3] ; Tm = xtime(Tm); (*state)[i][2] ^= Tm ^ Tmp ;
Tm = (*state)[i][3] ^ t ; Tm = xtime(Tm); (*state)[i][3] ^= Tm ^ Tmp ;
}
}
// Multiply is used to multiply numbers in the field GF(2^8)
// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary
// The compiler seems to be able to vectorize the operation better thithi way
static uint8_t Multiply(uint8_t x, uint8_t y)
{
return (((y & 1) * x) ^
((y>>1 & 1) * xtime(x)) ^
((y>>2 & 1) * xtime(xtime(x))) ^
((y>>3 & 1) * xtime(xtime(xtime(x)))) ^
((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */
}
#else
#define Multiply(x, y)
( ((y & 1) * x) ^
((y>>1 & 1) * xtime(x)) ^
((y>>2 & 1) * xtime(xtime(x))) ^
((y>>3 & 1) * xtime(xtime(xtime(x)))) ^
((y>>4 & 1) * xtime(xtime(xtime(xtime(x))))))
#endif
// MixColumns function mixes the columns of the state matrix.
// The method used to multiply may be difficult to understand for the inexperienced.
static void InvMixColumns(state_t* state)
{
int i;
uint8_t a, b, c, d;
for (i = 0; i < 4; ++i)
{
a = (*state)[i][0];
b = (*state)[i][1];
c = (*state)[i][2];
d = (*state)[i][3];
(*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
(*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
(*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
(*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e);
}
}
// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
static void InvSubBytes(state_t* state)
{
uint8_t i, j;
for (i = 0; i < 4; ++i)
{
for (j = 0; j < 4; ++j)
{
(*state)[j][i] = getSBoxInvert((*state)[j][i]);
}
}
}
static void InvShiftRows(state_t* state)
{
uint8_t temp;
// Rotate first row 1 columns to right
temp = (*state)[3][1];
(*state)[3][1] = (*state)[2][1];
(*state)[2][1] = (*state)[1][1];
(*state)[1][1] = (*state)[0][1];
(*state)[0][1] = temp;
// Rotate second row 2 columns to right
temp = (*state)[0][2];
(*state)[0][2] = (*state)[2][2];
(*state)[2][2] = temp;
temp = (*state)[1][2];
(*state)[1][2] = (*state)[3][2];
(*state)[3][2] = temp;
// Rotate third row 3 columns to right
temp = (*state)[0][3];
(*state)[0][3] = (*state)[1][3];
(*state)[1][3] = (*state)[2][3];
(*state)[2][3] = (*state)[3][3];
(*state)[3][3] = temp;
}
// Cipher is the main function that encrypts the PlainText.
static void Cipher(state_t* state, uint8_t* RoundKey)
{
uint8_t round = 0;
// Add the First round key to the state before starting the rounds.
AddRoundKey(0, state, RoundKey);
// There will be Nr rounds.
// The first Nr-1 rounds are identical.
// These Nr-1 rounds are executed in the loop below.
for (round = 1; round < Nr; ++round)
{
SubBytes(state);
ShiftRows(state);
MixColumns(state);
AddRoundKey(round, state, RoundKey);
}
// The last round is given below.
// The MixColumns function is not here in the last round.
SubBytes(state);
ShiftRows(state);
AddRoundKey(Nr, state, RoundKey);
}
static void InvCipher(state_t* state,uint8_t* RoundKey)
{
uint8_t round = 0;
// Add the First round key to the state before starting the rounds.
AddRoundKey(Nr, state, RoundKey);
// There will be Nr rounds.
// The first Nr-1 rounds are identical.
// These Nr-1 rounds are executed in the loop below.
for (round = (Nr - 1); round > 0; --round)
{
InvShiftRows(state);
InvSubBytes(state);
AddRoundKey(round, state, RoundKey);
InvMixColumns(state);
}
// The last round is given below.
// The MixColumns function is not here in the last round.
InvShiftRows(state);
InvSubBytes(state);
AddRoundKey(0, state, RoundKey);
}
/*****************************************************************************/
/* Public functions: */
/*****************************************************************************/
#if defined(ECB) && (ECB == 1)
void AES_ECB_encrypt(struct AES_ctx *ctx, uint8_t* buf)
{
// The next function call encrypts the PlainText with the Key using AES algorithm.
Cipher((state_t*)buf, ctx->RoundKey);
}
void AES_ECB_decrypt(struct AES_ctx* ctx, uint8_t* buf)
{
// The next function call decrypts the PlainText with the Key using AES algorithm.
InvCipher((state_t*)buf, ctx->RoundKey);
}
#endif // #if defined(ECB) && (ECB == 1)
#if defined(CBC) && (CBC == 1)
static void XorWithIv(uint8_t* buf, uint8_t* Iv)
{
uint8_t i;
for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size
{
buf[i] ^= Iv[i];
}
}
void AES_CBC_encrypt_buffer(struct AES_ctx *ctx,uint8_t* buf, uint32_t length)
{
uintptr_t i;
uint8_t *Iv = ctx->Iv;
for (i = 0; i < length; i += AES_BLOCKLEN)
{
XorWithIv(buf, Iv);
Cipher((state_t*)buf, ctx->RoundKey);
Iv = buf;
buf += AES_BLOCKLEN;
//printf("Step %d - %d", i/16, i);
}
/* store Iv in ctx for next call */
memcpy(ctx->Iv, Iv, AES_BLOCKLEN);
}
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length)
{
uintptr_t i;
uint8_t storeNextIv[AES_BLOCKLEN];
for (i = 0; i < length; i += AES_BLOCKLEN)
{
memcpy(storeNextIv, buf, AES_BLOCKLEN);
InvCipher((state_t*)buf, ctx->RoundKey);
XorWithIv(buf, ctx->Iv);
memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN);
buf += AES_BLOCKLEN;
}
}
#endif // #if defined(CBC) && (CBC == 1)
#if defined(CTR) && (CTR == 1)
/* Symmetrical operation: same function for encrypting as for decrypting. Note any IV/nonce should never be reused with the same key */
void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length)
{
uint8_t buffer[AES_BLOCKLEN];
unsigned i;
int bi;
for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi)
{
if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */
{
memcpy(buffer, ctx->Iv, AES_BLOCKLEN);
Cipher((state_t*)buffer,ctx->RoundKey);
/* Increment Iv and handle overflow */
for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi)
{
/* inc will owerflow */
if (ctx->Iv[bi] == 255)
{
ctx->Iv[bi] = 0;
continue;
}
ctx->Iv[bi] += 1;
break;
}
bi = 0;
}
buf[i] = (buf[i] ^ buffer[bi]);
}
}
#endif // #if defined(CTR) && (CTR == 1)
aes.h
#ifndef _AES_H_
#define _AES_H_
#include <stdint.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 1
#endif
#ifndef CTR
#define CTR 1
#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(struct AES_ctx* ctx, uint8_t* buf);
void AES_ECB_decrypt(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;
// 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, uint32_t length);
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_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
// 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, uint32_t length);
#endif // #if defined(CTR) && (CTR == 1)
#endif //_AES_H_
aes.hpp
#ifndef _AES_HPP_
#define _AES_HPP_
#ifndef __cplusplus
#error Do not include the hpp header in a c project!
#endif //__cplusplus
extern "C" {
#include "aes.h"
}
#endif //_AES_HPP_
test.c
#include <stdio.h>
#include <string.h>
#include <stdint.h>
// Enable ECB, CTR and CBC mode. Note this can be done before including aes.h or at compile-time.
// E.g. with GCC by using the -D flag: gcc -c aes.c -DCBC=0 -DCTR=1 -DECB=1
#define CBC 1
#define CTR 1
#define ECB 1
#include "aes.h"
static void phex(uint8_t* str);
static void test_encrypt_cbc(void);
static void test_decrypt_cbc(void);
static void test_encrypt_ctr(void);
static void test_decrypt_ctr(void);
static void test_encrypt_ecb(void);
static void test_decrypt_ecb(void);
static void test_encrypt_ecb_verbose(void);
int main(void)
{
#ifdef AES128
printf(" Testing AES128 ");
#elif defined(AES192)
printf(" Testing AES192 ");
#elif defined(AES256)
printf(" Testing AES256 ");
#else
printf("You need to specify a symbol between AES128, AES192 or AES256. Exiting");
return 0;
#endif
test_encrypt_cbc();
test_decrypt_cbc();
test_encrypt_ctr();
test_decrypt_ctr();
test_decrypt_ecb();
test_encrypt_ecb();
test_encrypt_ecb_verbose();
return 0;
}
// prints string as hex
static void phex(uint8_t* str)
{
#ifdef AES128
uint8_t len = 16;
#elif defined(AES192)
uint8_t len = 24;
#elif defined(AES256)
uint8_t len = 32;
#endif
unsigned char i;
for (i = 0; i < len; ++i)
printf("%.2x", str[i]);
printf(" ");
}
static void test_encrypt_ecb_verbose(void)
{
// Example of more verbose verification
uint8_t i, buf[64], buf2[64];
// 128bit key
uint8_t key[16] = { (uint8_t) 0x2b, (uint8_t) 0x7e, (uint8_t) 0x15, (uint8_t) 0x16, (uint8_t) 0x28, (uint8_t) 0xae, (uint8_t) 0xd2, (uint8_t) 0xa6, (uint8_t) 0xab, (uint8_t) 0xf7, (uint8_t) 0x15, (uint8_t) 0x88, (uint8_t) 0x09, (uint8_t) 0xcf, (uint8_t) 0x4f, (uint8_t) 0x3c };
// 512bit text
uint8_t plain_text[64] = { (uint8_t) 0x6b, (uint8_t) 0xc1, (uint8_t) 0xbe, (uint8_t) 0xe2, (uint8_t) 0x2e, (uint8_t) 0x40, (uint8_t) 0x9f, (uint8_t) 0x96, (uint8_t) 0xe9, (uint8_t) 0x3d, (uint8_t) 0x7e, (uint8_t) 0x11, (uint8_t) 0x73, (uint8_t) 0x93, (uint8_t) 0x17, (uint8_t) 0x2a,
(uint8_t) 0xae, (uint8_t) 0x2d, (uint8_t) 0x8a, (uint8_t) 0x57, (uint8_t) 0x1e, (uint8_t) 0x03, (uint8_t) 0xac, (uint8_t) 0x9c, (uint8_t) 0x9e, (uint8_t) 0xb7, (uint8_t) 0x6f, (uint8_t) 0xac, (uint8_t) 0x45, (uint8_t) 0xaf, (uint8_t) 0x8e, (uint8_t) 0x51,
(uint8_t) 0x30, (uint8_t) 0xc8, (uint8_t) 0x1c, (uint8_t) 0x46, (uint8_t) 0xa3, (uint8_t) 0x5c, (uint8_t) 0xe4, (uint8_t) 0x11, (uint8_t) 0xe5, (uint8_t) 0xfb, (uint8_t) 0xc1, (uint8_t) 0x19, (uint8_t) 0x1a, (uint8_t) 0x0a, (uint8_t) 0x52, (uint8_t) 0xef,
(uint8_t) 0xf6, (uint8_t) 0x9f, (uint8_t) 0x24, (uint8_t) 0x45, (uint8_t) 0xdf, (uint8_t) 0x4f, (uint8_t) 0x9b, (uint8_t) 0x17, (uint8_t) 0xad, (uint8_t) 0x2b, (uint8_t) 0x41, (uint8_t) 0x7b, (uint8_t) 0xe6, (uint8_t) 0x6c, (uint8_t) 0x37, (uint8_t) 0x10 };
memset(buf, 0, 64);
memset(buf2, 0, 64);
// print text to encrypt, key and IV
printf("ECB encrypt verbose: ");
printf("plain text: ");
for (i = (uint8_t) 0; i < (uint8_t) 4; ++i)
{
phex(plain_text + i * (uint8_t) 16);
}
printf(" ");
printf("key: ");
phex(key);
printf(" ");
// print the resulting cipher as 4 x 16 byte strings
printf("ciphertext: ");
struct AES_ctx ctx;
AES_init_ctx(&ctx, key);
for (i = 0; i < 4; ++i)
{
AES_ECB_encrypt(&ctx, plain_text + (i * 16));
phex(plain_text + (i * 16));
}
printf(" ");
}
static void test_encrypt_ecb(void)
{
#ifdef AES128
uint8_t key[] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
uint8_t out[] = { 0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97 };
#elif defined(AES192)
uint8_t key[] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5,
0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b };
uint8_t out[] = { 0xbd, 0x33, 0x4f, 0x1d, 0x6e, 0x45, 0xf2, 0x5f, 0xf7, 0x12, 0xa2, 0x14, 0x57, 0x1f, 0xa5, 0xcc };
#elif defined(AES256)
uint8_t key[] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
uint8_t out[] = { 0xf3, 0xee, 0xd1, 0xbd, 0xb5, 0xd2, 0xa0, 0x3c, 0x06, 0x4b, 0x5a, 0x7e, 0x3d, 0xb1, 0x81, 0xf8 };
#endif
uint8_t in[] = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a };
struct AES_ctx ctx;
AES_init_ctx(&ctx, key);
AES_ECB_encrypt(&ctx, in);
printf("ECB encrypt: ");
if (0 == memcmp((char*) out, (char*) in, 16))
{
printf("SUCCESS! ");
}
else
{
printf("FAILURE! ");
}
}
static void test_decrypt_cbc(void)
{
#ifdef AES128
uint8_t key[] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
uint8_t in[] = { 0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46, 0xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
0x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee, 0x95, 0xdb, 0x11, 0x3a, 0x91, 0x76, 0x78, 0xb2,
0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16,
0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, 0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7 };
#elif defined(AES192)
uint8_t key[] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5, 0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b };
uint8_t in[] = { 0x4f, 0x02, 0x1d, 0xb2, 0x43, 0xbc, 0x63, 0x3d, 0x71, 0x78, 0x18, 0x3a, 0x9f, 0xa0, 0x71, 0xe8,
0xb4, 0xd9, 0xad, 0xa9, 0xad, 0x7d, 0xed, 0xf4, 0xe5, 0xe7, 0x38, 0x76, 0x3f, 0x69, 0x14, 0x5a,
0x57, 0x1b, 0x24, 0x20, 0x12, 0xfb, 0x7a, 0xe0, 0x7f, 0xa9, 0xba, 0xac, 0x3d, 0xf1, 0x02, 0xe0,
0x08, 0xb0, 0xe2, 0x79, 0x88, 0x59, 0x88, 0x81, 0xd9, 0x20, 0xa9, 0xe6, 0x4f, 0x56, 0x15, 0xcd };
#elif defined(AES256)
uint8_t key[] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
uint8_t in[] = { 0xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba, 0x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
0x9c, 0xfc, 0x4e, 0x96, 0x7e, 0xdb, 0x80, 0x8d, 0x67, 0x9f, 0x77, 0x7b, 0xc6, 0x70, 0x2c, 0x7d,
0x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf, 0xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61,
0xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc, 0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b };
#endif
uint8_t iv[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };
uint8_t out[] = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
// uint8_t buffer[64];
struct AES_ctx ctx;
AES_init_ctx_iv(&ctx, key, iv);
AES_CBC_decrypt_buffer(&ctx, in, 64);
printf("CBC decrypt: ");
if (0 == memcmp((char*) out, (char*) in, 64))
{
printf("SUCCESS! ");
}
else
{
printf("FAILURE! ");
}
}
static void test_encrypt_cbc(void)
{
#ifdef AES128
uint8_t key[] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
uint8_t out[] = { 0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46, 0xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
0x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee, 0x95, 0xdb, 0x11, 0x3a, 0x91, 0x76, 0x78, 0xb2,
0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b, 0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16,
0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, 0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7 };
#elif defined(AES192)
uint8_t key[] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5, 0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b };
uint8_t out[] = { 0x4f, 0x02, 0x1d, 0xb2, 0x43, 0xbc, 0x63, 0x3d, 0x71, 0x78, 0x18, 0x3a, 0x9f, 0xa0, 0x71, 0xe8,
0xb4, 0xd9, 0xad, 0xa9, 0xad, 0x7d, 0xed, 0xf4, 0xe5, 0xe7, 0x38, 0x76, 0x3f, 0x69, 0x14, 0x5a,
0x57, 0x1b, 0x24, 0x20, 0x12, 0xfb, 0x7a, 0xe0, 0x7f, 0xa9, 0xba, 0xac, 0x3d, 0xf1, 0x02, 0xe0,
0x08, 0xb0, 0xe2, 0x79, 0x88, 0x59, 0x88, 0x81, 0xd9, 0x20, 0xa9, 0xe6, 0x4f, 0x56, 0x15, 0xcd };
#elif defined(AES256)
uint8_t key[] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
uint8_t out[] = { 0xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba, 0x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
0x9c, 0xfc, 0x4e, 0x96, 0x7e, 0xdb, 0x80, 0x8d, 0x67, 0x9f, 0x77, 0x7b, 0xc6, 0x70, 0x2c, 0x7d,
0x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf, 0xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61,
0xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc, 0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b };
#endif
uint8_t iv[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f };
uint8_t in[] = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
struct AES_ctx ctx;
AES_init_ctx_iv(&ctx, key, iv);
AES_CBC_encrypt_buffer(&ctx, in, 64);
printf("CBC encrypt: ");
if (0 == memcmp((char*) out, (char*) in, 64))
{
printf("SUCCESS! ");
}
else
{
printf("FAILURE! ");
}
}
static void test_xcrypt_ctr(const char* xcrypt);
static void test_encrypt_ctr(void)
{
test_xcrypt_ctr("encrypt");
}
static void test_decrypt_ctr(void)
{
test_xcrypt_ctr("decrypt");
}
static void test_xcrypt_ctr(const char* xcrypt)
{
#ifdef AES128
uint8_t key[16] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
uint8_t in[64] = { 0x87, 0x4d, 0x61, 0x91, 0xb6, 0x20, 0xe3, 0x26, 0x1b, 0xef, 0x68, 0x64, 0x99, 0x0d, 0xb6, 0xce,
0x98, 0x06, 0xf6, 0x6b, 0x79, 0x70, 0xfd, 0xff, 0x86, 0x17, 0x18, 0x7b, 0xb9, 0xff, 0xfd, 0xff,
0x5a, 0xe4, 0xdf, 0x3e, 0xdb, 0xd5, 0xd3, 0x5e, 0x5b, 0x4f, 0x09, 0x02, 0x0d, 0xb0, 0x3e, 0xab,
0x1e, 0x03, 0x1d, 0xda, 0x2f, 0xbe, 0x03, 0xd1, 0x79, 0x21, 0x70, 0xa0, 0xf3, 0x00, 0x9c, 0xee };
#elif defined(AES192)
uint8_t key[24] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5,
0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b };
uint8_t in[64] = { 0x1a, 0xbc, 0x93, 0x24, 0x17, 0x52, 0x1c, 0xa2, 0x4f, 0x2b, 0x04, 0x59, 0xfe, 0x7e, 0x6e, 0x0b,
0x09, 0x03, 0x39, 0xec, 0x0a, 0xa6, 0xfa, 0xef, 0xd5, 0xcc, 0xc2, 0xc6, 0xf4, 0xce, 0x8e, 0x94,
0x1e, 0x36, 0xb2, 0x6b, 0xd1, 0xeb, 0xc6, 0x70, 0xd1, 0xbd, 0x1d, 0x66, 0x56, 0x20, 0xab, 0xf7,
0x4f, 0x78, 0xa7, 0xf6, 0xd2, 0x98, 0x09, 0x58, 0x5a, 0x97, 0xda, 0xec, 0x58, 0xc6, 0xb0, 0x50 };
#elif defined(AES256)
uint8_t key[32] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
uint8_t in[64] = { 0x60, 0x1e, 0xc3, 0x13, 0x77, 0x57, 0x89, 0xa5, 0xb7, 0xa7, 0xf5, 0x04, 0xbb, 0xf3, 0xd2, 0x28,
0xf4, 0x43, 0xe3, 0xca, 0x4d, 0x62, 0xb5, 0x9a, 0xca, 0x84, 0xe9, 0x90, 0xca, 0xca, 0xf5, 0xc5,
0x2b, 0x09, 0x30, 0xda, 0xa2, 0x3d, 0xe9, 0x4c, 0xe8, 0x70, 0x17, 0xba, 0x2d, 0x84, 0x98, 0x8d,
0xdf, 0xc9, 0xc5, 0x8d, 0xb6, 0x7a, 0xad, 0xa6, 0x13, 0xc2, 0xdd, 0x08, 0x45, 0x79, 0x41, 0xa6 };
#endif
uint8_t iv[16] = { 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff };
uint8_t out[64] = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
struct AES_ctx ctx;
AES_init_ctx_iv(&ctx, key, iv);
AES_CTR_xcrypt_buffer(&ctx, in, 64);
printf("CTR %s: ", xcrypt);
if (0 == memcmp((char *) out, (char *) in, 64))
{
printf("SUCCESS! ");
}
else
{
printf("FAILURE! ");
}
}
static void test_decrypt_ecb(void)
{
#ifdef AES128
uint8_t key[] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
uint8_t in[] = { 0x3a, 0xd7, 0x7b, 0xb4, 0x0d, 0x7a, 0x36, 0x60, 0xa8, 0x9e, 0xca, 0xf3, 0x24, 0x66, 0xef, 0x97 };
#elif defined(AES192)
uint8_t key[] = { 0x8e, 0x73, 0xb0, 0xf7, 0xda, 0x0e, 0x64, 0x52, 0xc8, 0x10, 0xf3, 0x2b, 0x80, 0x90, 0x79, 0xe5,
0x62, 0xf8, 0xea, 0xd2, 0x52, 0x2c, 0x6b, 0x7b };
uint8_t in[] = { 0xbd, 0x33, 0x4f, 0x1d, 0x6e, 0x45, 0xf2, 0x5f, 0xf7, 0x12, 0xa2, 0x14, 0x57, 0x1f, 0xa5, 0xcc };
#elif defined(AES256)
uint8_t key[] = { 0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe, 0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7, 0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4 };
uint8_t in[] = { 0xf3, 0xee, 0xd1, 0xbd, 0xb5, 0xd2, 0xa0, 0x3c, 0x06, 0x4b, 0x5a, 0x7e, 0x3d, 0xb1, 0x81, 0xf8 };
#endif
uint8_t out[] = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a };
struct AES_ctx ctx;
AES_init_ctx(&ctx, key);
AES_ECB_decrypt(&ctx, in);
printf("ECB decrypt: ");
if (0 == memcmp((char*) out, (char*) in, 16))
{
printf("SUCCESS! ");
}
else
{
printf("FAILURE! ");
}
}
Makefile
#CC = avr-gcc
#CFLAGS = -Wall -mmcu=atmega16 -Os -Wl,-Map,test.map
#OBJCOPY = avr-objcopy
CC = gcc
LD = gcc
CFLAGS = -Wall -Os -c
LDFLAGS = -Wall -Os -Wl,-Map,test.map
OBJCOPYFLAFS = -j .text -O ihex
OBJCOPY = objcopy
# include path to AVR library
INCLUDE_PATH = /usr/lib/avr/include
# splint static check
SPLINT = splint test.c aes.c -I$(INCLUDE_PATH) +charindex -unrecog
default: test.elf
.SILENT:
.PHONY: lint clean
test.hex : test.elf
echo copy object-code to new image and format in hex
$(OBJCOPY) ${OBJCOPYFLAFS} $< $@
test.o : test.c aes.h aes.o
echo [CC] $@
$(CC) $(CFLAGS) -o $@ $<
aes.o : aes.c aes.h
echo [CC] $@
$(CC) $(CFLAGS) -o $@ $<
test.elf : aes.o test.o
echo [LD] $@
$(LD) $(LDFLAGS) -o $@ $^
clean:
rm -f *.OBJ *.LST *.o *.gch *.out *.hex *.map
lint:
$(call SPLINT)
This is much simplified version , so that you can easily understand and edit. Thankyou.