diff --git a/aes.c b/aes.c new file mode 100755 index 0000000..c609c1f --- /dev/null +++ b/aes.c @@ -0,0 +1,595 @@ +/* + +This is an implementation of the AES algorithm, specifically ECB and CBC mode. +Block size can be chosen in aes.h - available choices are AES128, AES192, AES256. + +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. + For AES192/256 the block size is proportionally larger. + +*/ + + +/*****************************************************************************/ +/* Includes: */ +/*****************************************************************************/ +#include +#include // 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 +#define BLOCKLEN 16 //Block length in bytes AES is 128b block only + +#if defined(AES256) && (AES256 == 1) + #define Nk 8 + #define KEYLEN 32 + #define Nr 14 + #define keyExpSize 240 +#elif defined(AES192) && (AES192 == 1) + #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. +// 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[keyExpSize]; + +// The Key input to the AES Program +static const uint8_t* Key; + +#if defined(CBC) && CBC + // Initial Vector used only for CBC mode + static uint8_t* Iv; +#endif + +// 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) +static const uint8_t Rcon[11] = { + 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 }; + +/* + * Jordan Goulder points out in PR #12 (https://github.com/kokke/tiny-AES128-C/pull/12), + * that you can remove most of the elements in the Rcon array, because they are unused. + * + * From Wikipedia's article on the Rijndael key schedule @ https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon + * + * "Only the first some of these constants are actually used – up to rcon[10] for AES-128 (as 11 round keys are needed), + * up to rcon[8] for AES-192, up to rcon[7] for AES-256. rcon[0] is not used in AES algorithm." + * + * ... which is why the full array below has been 'disabled' below. + */ +#if 0 +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 }; +#endif + +/*****************************************************************************/ +/* 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, 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. + //i == Nk + for (; i < Nb * (Nr + 1); ++i) + { + { + 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 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 + 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); +} + + +/*****************************************************************************/ +/* Public functions: */ +/*****************************************************************************/ +#if defined(ECB) && (ECB == 1) + + +void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* output, const uint32_t length) +{ + // Copy input to output, and work in-memory on output + memcpy(output, input, length); + state = (state_t*)output; + + Key = key; + KeyExpansion(); + + // The next function call encrypts the PlainText with the Key using AES algorithm. + Cipher(); +} + +void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length) +{ + // Copy input to output, and work in-memory on output + memcpy(output, input, length); + state = (state_t*)output; + + // The KeyExpansion routine must be called before encryption. + Key = key; + KeyExpansion(); + + InvCipher(); +} + + +#endif // #if defined(ECB) && (ECB == 1) + + + + + +#if defined(CBC) && (CBC == 1) + + +static void XorWithIv(uint8_t* buf) +{ + uint8_t i; + for (i = 0; i < BLOCKLEN; ++i) //WAS for(i = 0; i < KEYLEN; ++i) but the block in AES is always 128bit so 16 bytes! + { + buf[i] ^= Iv[i]; + } +} + +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 extra = length % BLOCKLEN; /* Remaining bytes in the last non-full block */ + + // 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 += BLOCKLEN) + { + XorWithIv(input); + memcpy(output, input, BLOCKLEN); + state = (state_t*)output; + Cipher(); + Iv = output; + input += BLOCKLEN; + output += BLOCKLEN; + //printf("Step %d - %d", i/16, i); + } + + if (extra) + { + memcpy(output, input, extra); + state = (state_t*)output; + Cipher(); + } +} + +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 extra = length % BLOCKLEN; /* Remaining bytes in the last non-full block */ + + // 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 += BLOCKLEN) + { + memcpy(output, input, BLOCKLEN); + state = (state_t*)output; + InvCipher(); + XorWithIv(output); + Iv = input; + input += BLOCKLEN; + output += BLOCKLEN; + } + + if (extra) + { + memcpy(output, input, extra); + state = (state_t*)output; + InvCipher(); + } +} + +#endif // #if defined(CBC) && (CBC == 1) diff --git a/aes.h b/aes.h new file mode 100755 index 0000000..8dd2d3b --- /dev/null +++ b/aes.h @@ -0,0 +1,41 @@ +#ifndef _AES_H_ +#define _AES_H_ + +#include + + +// #define the macros below to 1/0 to enable/disable the mode of operation. +// +// CBC enables AES encryption in CBC-mode of operation. +// ECB enables the basic ECB 16-byte block algorithm. Both 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 + +#define AES128 1 +//#define AES192 1 +//#define AES256 1 + +#if defined(ECB) && (ECB == 1) + +void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length); +void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length); + +#endif // #if defined(ECB) && (ECB == !) + + +#if defined(CBC) && (CBC == 1) + +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 == 1) + + +#endif //_AES_H_ diff --git a/encryption.cpp b/encryption.cpp new file mode 100755 index 0000000..3fabfc1 --- /dev/null +++ b/encryption.cpp @@ -0,0 +1,76 @@ +#include +#include +#include +#include +#include +#include + +//static uint64_t seq=1; + +static uint8_t zero_iv[]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0};//this prog use zero iv,you should make sure first block of data contains a random/nonce data + +static uint8_t g_key[]={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16, 0,0,0,0}; + +static uint8_t buf[65535+100]; + + +int my_encrypt(uint8_t *data,uint8_t *output,int &len,uint8_t * key) +{ + memcpy(output,data,len); + return 0; + + int ori_len=len; + + len=len+16;//md5 + len+=2;//length + + if(len%16!=0) + { + len= (len/16)*16+16; + } + + if(len>65535) return -1; + + data[len-16-2]=(uint16_t(ori_len))>>8; + data[len-16-1]=((uint16_t(ori_len))<<8)>>8; + + + //printf("%d %d\n",data[len-16-2],data[len-16-1]); + md5(data,len-16,data+len-16); + + //memcpy(buf,data,len); //not thread safe + + AES_CBC_encrypt_buffer((unsigned char *)output,(unsigned char *)data,len,(unsigned char *)key,(unsigned char *)zero_iv); + //it doesnt allow over lap + + return 0; +} +int my_decrypt(uint8_t *data,uint8_t *output,int &len,uint8_t * key) +{ + memcpy(output,data,len); + return 0; + + uint8_t md5_res[16]; + if(len>65535) return -1; + if(len<32) return -1; + if(len%16 !=0) return -1; + + //memcpy(buf,data,len); + + AES_CBC_decrypt_buffer((unsigned char *)output,(unsigned char *)data,len,(unsigned char *)key,(unsigned char *)zero_iv); + + //printf("%d %d\n",data[len-16-2],data[len-16-1]); + + //printf("<<%d>>",len); + md5(output,len-16,md5_res); + + if(memcmp(output+len-16,md5_res,16)!=0) + { + return -2; + } + + len=output[len-16-2]*256u+output[len-16-1]; + + return 0; +} + diff --git a/encryption.h b/encryption.h new file mode 100755 index 0000000..ac8c865 --- /dev/null +++ b/encryption.h @@ -0,0 +1,11 @@ +#ifndef _ENCRYPTION_H_ +#define _ENCRYPTION_H_ +#include +#include +#include +#include +#include +#include +int my_encrypt(uint8_t *data,uint8_t *output,int &len,uint8_t * key); +int my_decrypt(uint8_t *data,uint8_t *output,int &len,uint8_t * key); +#endif