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authorkokke <spam@rowdy.dk>2014-12-15 21:19:53 +0100
committerkokke <spam@rowdy.dk>2014-12-15 21:19:53 +0100
commita3f4606cb4def8cd528688e056a60d5899ab0447 (patch)
treef40a5a85067c1fd9e7453cbd8dc0143f4be82b39
parentIncluded CBC mode (diff)
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-rw-r--r--aes_cbc.c581
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diff --git a/aes_cbc.c b/aes_cbc.c
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--- a/aes_cbc.c
+++ /dev/null
@@ -1,581 +0,0 @@
-/*
-
-This is an implementation of the AES128 algorithm, specifically ECB and CBC mode.
-
-The implementation is verified against the test vectors in:
- National Institute of Standards and Technology Special Publication 800-38A 2001 ED
-
-ECB-AES128
-----------
-
- 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.
-
-*/
-
-
-/*****************************************************************************/
-/* 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
-// 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
-
-// jcallan@github points out that declaring Multiply as a function
-// reduces code size considerably with the Keil ARM compiler.
-// See this link for more information: https://github.com/kokke/tiny-AES128-C/pull/3
-#ifndef MULTIPLY_AS_A_FUNCTION
- #define MULTIPLY_AS_A_FUNCTION 0
-#endif
-
-
-/*****************************************************************************/
-/* Private variables: */
-/*****************************************************************************/
-// state - array holding the intermediate results during decryption.
-typedef uint8_t state_t[4][4];
-static state_t* state;
-
-// The array that stores the round keys.
-static uint8_t RoundKey[176];
-
-// The Key input to the AES Program
-static const uint8_t* Key;
-
-// Initial Vector used for CBC mode etc.
-static uint8_t* Iv;
-
-// 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 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 };
-
-
-/*****************************************************************************/
-/* Private functions: */
-/*****************************************************************************/
-static uint8_t getSBoxValue(uint8_t num)
-{
- return sbox[num];
-}
-
-static uint8_t getSBoxInvert(uint8_t num)
-{
- return 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(void)
-{
- uint32_t 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 < (Nb * (Nr + 1))); ++i)
- {
- for(j = 0; j < 4; ++j)
- {
- tempa[j]=RoundKey[(i-1) * 4 + j];
- }
- if (i % Nk == 0)
- {
- // This function rotates 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];
- }
- else if (Nk > 6 && 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]);
- }
- }
- 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];
- RoundKey[i * 4 + 3] = RoundKey[(i - Nk) * 4 + 3] ^ tempa[3];
- }
-}
-
-// 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)
-{
- 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(void)
-{
- 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(void)
-{
- 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(void)
-{
- 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)
-#if MULTIPLY_AS_A_FUNCTION
-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))))));
- }
-#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.
-// Please use the references to gain more information.
-static void InvMixColumns(void)
-{
- 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(void)
-{
- 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(void)
-{
- 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(void)
-{
- uint8_t round = 0;
-
- // Add the First round key to the state before starting the rounds.
- AddRoundKey(0);
-
- // 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();
- ShiftRows();
- MixColumns();
- AddRoundKey(round);
- }
-
- // The last round is given below.
- // The MixColumns function is not here in the last round.
- SubBytes();
- ShiftRows();
- AddRoundKey(Nr);
-}
-
-static void InvCipher(void)
-{
- uint8_t round=0;
-
- // Add the First round key to the state before starting the rounds.
- AddRoundKey(Nr);
-
- // 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();
- InvSubBytes();
- AddRoundKey(round);
- InvMixColumns();
- }
-
- // The last round is given below.
- // The MixColumns function is not here in the last round.
- InvShiftRows();
- InvSubBytes();
- AddRoundKey(0);
-}
-
-static void BlockCopy(uint8_t* output, uint8_t* input)
-{
- uint8_t i;
- for (i=0;i<KEYLEN;++i)
- {
- output[i] = input[i];
- }
-}
-
-
-
-/*****************************************************************************/
-/* Public functions: */
-/*****************************************************************************/
-#if defined(ECB) && ECB
-
-
-void AES128_ECB_encrypt(uint8_t* input, const uint8_t* key, uint8_t* output)
-{
- // Copy input to output, and work in-memory on output
- BlockCopy(output, input);
- state = (state_t*)output;
-
- Key = key;
- KeyExpansion();
-
- // The next function call encrypts the PlainText with the Key using AES algorithm.
- Cipher();
-}
-
-void AES128_ECB_decrypt(uint8_t* input, const uint8_t* key, uint8_t *output)
-{
- // Copy input to output, and work in-memory on output
- BlockCopy(output, input);
- state = (state_t*)output;
-
- // The KeyExpansion routine must be called before encryption.
- Key = key;
- KeyExpansion();
-
- InvCipher();
-}
-
-
-#endif // #if defined(ECB) && ECB
-
-
-
-
-
-#if defined(CBC) && CBC
-
-
-static void XorWithIv(uint8_t* buf)
-{
- uint8_t i;
- for(i = 0; i < KEYLEN; ++i)
- {
- buf[i] ^= Iv[i];
- }
-}
-
-void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
-{
- intptr_t i;
- uint8_t remainders = length % KEYLEN; /* Remaining bytes in the last non-full block */
-
- BlockCopy(output, input);
- state = (state_t*)output;
-
- // Skip the key expansion if key is passed as 0
- if(0 != key)
- {
- Key = key;
- KeyExpansion();
- }
-
- if(iv != 0)
- {
- Iv = (uint8_t*)iv;
- }
-
- for(i = 0; i < length; i += KEYLEN)
- {
- XorWithIv(input);
- BlockCopy(output, input);
- state = (state_t*)output;
- Cipher();
- Iv = output;
- input += KEYLEN;
- output += KEYLEN;
- }
-
- if(remainders)
- {
- BlockCopy(output, input);
- memset(output + remainders, 0, KEYLEN - remainders); /* add 0-padding */
- state = (state_t*)output;
- Cipher();
- }
-}
-
-void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
-{
- intptr_t i;
- uint8_t remainders = length % KEYLEN; /* Remaining bytes in the last non-full block */
-
- BlockCopy(output, input);
- state = (state_t*)output;
-
- // Skip the key expansion if key is passed as 0
- if(0 != key)
- {
- Key = key;
- KeyExpansion();
- }
-
- // If iv is passed as 0, we continue to encrypt without re-setting the Iv
- if(iv != 0)
- {
- Iv = (uint8_t*)iv;
- }
-
- for(i = 0; i < length; i += KEYLEN)
- {
- BlockCopy(output, input);
- state = (state_t*)output;
- InvCipher();
- XorWithIv(output);
- Iv = input;
- input += KEYLEN;
- output += KEYLEN;
- }
-
- if(remainders)
- {
- BlockCopy(output, input);
- memset(output+remainders, 0, KEYLEN - remainders); /* add 0-padding */
- state = (state_t*)output;
- InvCipher();
- }
-}
-
-
-#endif // #if defined(CBC) && CBC
-
-