1073 lines
41 KiB
C
1073 lines
41 KiB
C
/*********************************************************************
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* Filename: aes.c
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* Author: Brad Conte (brad AT bradconte.com)
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* Copyright:
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* Disclaimer: This code is presented "as is" without any guarantees.
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* Details: This code is the implementation of the AES algorithm and
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the CTR, CBC, and CCM modes of operation it can be used in.
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AES is, specified by the NIST in in publication FIPS PUB 197,
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availible at:
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* http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf .
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The CBC and CTR modes of operation are specified by
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NIST SP 800-38 A, available at:
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* http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf .
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The CCM mode of operation is specified by NIST SP80-38 C, available at:
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* http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
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*********************************************************************/
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/*************************** HEADER FILES ***************************/
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#include <stdlib.h>
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#include <memory.h>
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#include "aes.h"
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#include <stdio.h>
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#include <string.h>
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/****************************** MACROS ******************************/
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// The least significant byte of the word is rotated to the end.
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#define KE_ROTWORD(x) (((x) << 8) | ((x) >> 24))
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#define TRUE 1
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#define FALSE 0
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/**************************** DATA TYPES ****************************/
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#define AES_128_ROUNDS 10
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#define AES_192_ROUNDS 12
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#define AES_256_ROUNDS 14
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/*********************** FUNCTION DECLARATIONS **********************/
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void ccm_prepare_first_ctr_blk(BYTE counter[], const BYTE nonce[], int nonce_len, int payload_len_store_size);
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void ccm_prepare_first_format_blk(BYTE buf[], int assoc_len, int payload_len, int payload_len_store_size, int mac_len, const BYTE nonce[], int nonce_len);
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void ccm_format_assoc_data(BYTE buf[], int *end_of_buf, const BYTE assoc[], int assoc_len);
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void ccm_format_payload_data(BYTE buf[], int *end_of_buf, const BYTE payload[], int payload_len);
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/**************************** VARIABLES *****************************/
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// This is the specified AES SBox. To look up a substitution value, put the first
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// nibble in the first index (row) and the second nibble in the second index (column).
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static const BYTE aes_sbox[16][16] = {
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{0x63,0x7C,0x77,0x7B,0xF2,0x6B,0x6F,0xC5,0x30,0x01,0x67,0x2B,0xFE,0xD7,0xAB,0x76},
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{0xCA,0x82,0xC9,0x7D,0xFA,0x59,0x47,0xF0,0xAD,0xD4,0xA2,0xAF,0x9C,0xA4,0x72,0xC0},
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{0xB7,0xFD,0x93,0x26,0x36,0x3F,0xF7,0xCC,0x34,0xA5,0xE5,0xF1,0x71,0xD8,0x31,0x15},
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{0x04,0xC7,0x23,0xC3,0x18,0x96,0x05,0x9A,0x07,0x12,0x80,0xE2,0xEB,0x27,0xB2,0x75},
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{0x09,0x83,0x2C,0x1A,0x1B,0x6E,0x5A,0xA0,0x52,0x3B,0xD6,0xB3,0x29,0xE3,0x2F,0x84},
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{0x53,0xD1,0x00,0xED,0x20,0xFC,0xB1,0x5B,0x6A,0xCB,0xBE,0x39,0x4A,0x4C,0x58,0xCF},
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{0xD0,0xEF,0xAA,0xFB,0x43,0x4D,0x33,0x85,0x45,0xF9,0x02,0x7F,0x50,0x3C,0x9F,0xA8},
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{0x51,0xA3,0x40,0x8F,0x92,0x9D,0x38,0xF5,0xBC,0xB6,0xDA,0x21,0x10,0xFF,0xF3,0xD2},
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{0xCD,0x0C,0x13,0xEC,0x5F,0x97,0x44,0x17,0xC4,0xA7,0x7E,0x3D,0x64,0x5D,0x19,0x73},
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{0x60,0x81,0x4F,0xDC,0x22,0x2A,0x90,0x88,0x46,0xEE,0xB8,0x14,0xDE,0x5E,0x0B,0xDB},
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{0xE0,0x32,0x3A,0x0A,0x49,0x06,0x24,0x5C,0xC2,0xD3,0xAC,0x62,0x91,0x95,0xE4,0x79},
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{0xE7,0xC8,0x37,0x6D,0x8D,0xD5,0x4E,0xA9,0x6C,0x56,0xF4,0xEA,0x65,0x7A,0xAE,0x08},
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{0xBA,0x78,0x25,0x2E,0x1C,0xA6,0xB4,0xC6,0xE8,0xDD,0x74,0x1F,0x4B,0xBD,0x8B,0x8A},
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{0x70,0x3E,0xB5,0x66,0x48,0x03,0xF6,0x0E,0x61,0x35,0x57,0xB9,0x86,0xC1,0x1D,0x9E},
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{0xE1,0xF8,0x98,0x11,0x69,0xD9,0x8E,0x94,0x9B,0x1E,0x87,0xE9,0xCE,0x55,0x28,0xDF},
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{0x8C,0xA1,0x89,0x0D,0xBF,0xE6,0x42,0x68,0x41,0x99,0x2D,0x0F,0xB0,0x54,0xBB,0x16}
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};
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static const BYTE aes_invsbox[16][16] = {
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{0x52,0x09,0x6A,0xD5,0x30,0x36,0xA5,0x38,0xBF,0x40,0xA3,0x9E,0x81,0xF3,0xD7,0xFB},
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{0x7C,0xE3,0x39,0x82,0x9B,0x2F,0xFF,0x87,0x34,0x8E,0x43,0x44,0xC4,0xDE,0xE9,0xCB},
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{0x54,0x7B,0x94,0x32,0xA6,0xC2,0x23,0x3D,0xEE,0x4C,0x95,0x0B,0x42,0xFA,0xC3,0x4E},
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{0x08,0x2E,0xA1,0x66,0x28,0xD9,0x24,0xB2,0x76,0x5B,0xA2,0x49,0x6D,0x8B,0xD1,0x25},
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{0x72,0xF8,0xF6,0x64,0x86,0x68,0x98,0x16,0xD4,0xA4,0x5C,0xCC,0x5D,0x65,0xB6,0x92},
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{0x6C,0x70,0x48,0x50,0xFD,0xED,0xB9,0xDA,0x5E,0x15,0x46,0x57,0xA7,0x8D,0x9D,0x84},
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{0x90,0xD8,0xAB,0x00,0x8C,0xBC,0xD3,0x0A,0xF7,0xE4,0x58,0x05,0xB8,0xB3,0x45,0x06},
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{0xD0,0x2C,0x1E,0x8F,0xCA,0x3F,0x0F,0x02,0xC1,0xAF,0xBD,0x03,0x01,0x13,0x8A,0x6B},
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{0x3A,0x91,0x11,0x41,0x4F,0x67,0xDC,0xEA,0x97,0xF2,0xCF,0xCE,0xF0,0xB4,0xE6,0x73},
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{0x96,0xAC,0x74,0x22,0xE7,0xAD,0x35,0x85,0xE2,0xF9,0x37,0xE8,0x1C,0x75,0xDF,0x6E},
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{0x47,0xF1,0x1A,0x71,0x1D,0x29,0xC5,0x89,0x6F,0xB7,0x62,0x0E,0xAA,0x18,0xBE,0x1B},
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{0xFC,0x56,0x3E,0x4B,0xC6,0xD2,0x79,0x20,0x9A,0xDB,0xC0,0xFE,0x78,0xCD,0x5A,0xF4},
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{0x1F,0xDD,0xA8,0x33,0x88,0x07,0xC7,0x31,0xB1,0x12,0x10,0x59,0x27,0x80,0xEC,0x5F},
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{0x60,0x51,0x7F,0xA9,0x19,0xB5,0x4A,0x0D,0x2D,0xE5,0x7A,0x9F,0x93,0xC9,0x9C,0xEF},
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{0xA0,0xE0,0x3B,0x4D,0xAE,0x2A,0xF5,0xB0,0xC8,0xEB,0xBB,0x3C,0x83,0x53,0x99,0x61},
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{0x17,0x2B,0x04,0x7E,0xBA,0x77,0xD6,0x26,0xE1,0x69,0x14,0x63,0x55,0x21,0x0C,0x7D}
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};
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// This table stores pre-calculated values for all possible GF(2^8) calculations.This
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// table is only used by the (Inv)MixColumns steps.
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// USAGE: The second index (column) is the coefficient of multiplication. Only 7 different
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// coefficients are used: 0x01, 0x02, 0x03, 0x09, 0x0b, 0x0d, 0x0e, but multiplication by
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// 1 is negligible leaving only 6 coefficients. Each column of the table is devoted to one
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// of these coefficients, in the ascending order of value, from values 0x00 to 0xFF.
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static const BYTE gf_mul[256][6] = {
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{0x00,0x00,0x00,0x00,0x00,0x00},{0x02,0x03,0x09,0x0b,0x0d,0x0e},
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{0x04,0x06,0x12,0x16,0x1a,0x1c},{0x06,0x05,0x1b,0x1d,0x17,0x12},
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{0x08,0x0c,0x24,0x2c,0x34,0x38},{0x0a,0x0f,0x2d,0x27,0x39,0x36},
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{0x0c,0x0a,0x36,0x3a,0x2e,0x24},{0x0e,0x09,0x3f,0x31,0x23,0x2a},
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{0x10,0x18,0x48,0x58,0x68,0x70},{0x12,0x1b,0x41,0x53,0x65,0x7e},
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{0x14,0x1e,0x5a,0x4e,0x72,0x6c},{0x16,0x1d,0x53,0x45,0x7f,0x62},
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{0x18,0x14,0x6c,0x74,0x5c,0x48},{0x1a,0x17,0x65,0x7f,0x51,0x46},
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{0x1c,0x12,0x7e,0x62,0x46,0x54},{0x1e,0x11,0x77,0x69,0x4b,0x5a},
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{0x20,0x30,0x90,0xb0,0xd0,0xe0},{0x22,0x33,0x99,0xbb,0xdd,0xee},
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{0x24,0x36,0x82,0xa6,0xca,0xfc},{0x26,0x35,0x8b,0xad,0xc7,0xf2},
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{0x28,0x3c,0xb4,0x9c,0xe4,0xd8},{0x2a,0x3f,0xbd,0x97,0xe9,0xd6},
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{0x2c,0x3a,0xa6,0x8a,0xfe,0xc4},{0x2e,0x39,0xaf,0x81,0xf3,0xca},
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{0x30,0x28,0xd8,0xe8,0xb8,0x90},{0x32,0x2b,0xd1,0xe3,0xb5,0x9e},
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{0x34,0x2e,0xca,0xfe,0xa2,0x8c},{0x36,0x2d,0xc3,0xf5,0xaf,0x82},
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{0x38,0x24,0xfc,0xc4,0x8c,0xa8},{0x3a,0x27,0xf5,0xcf,0x81,0xa6},
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{0x3c,0x22,0xee,0xd2,0x96,0xb4},{0x3e,0x21,0xe7,0xd9,0x9b,0xba},
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{0x40,0x60,0x3b,0x7b,0xbb,0xdb},{0x42,0x63,0x32,0x70,0xb6,0xd5},
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{0x44,0x66,0x29,0x6d,0xa1,0xc7},{0x46,0x65,0x20,0x66,0xac,0xc9},
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{0x48,0x6c,0x1f,0x57,0x8f,0xe3},{0x4a,0x6f,0x16,0x5c,0x82,0xed},
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{0x4c,0x6a,0x0d,0x41,0x95,0xff},{0x4e,0x69,0x04,0x4a,0x98,0xf1},
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{0x50,0x78,0x73,0x23,0xd3,0xab},{0x52,0x7b,0x7a,0x28,0xde,0xa5},
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{0x54,0x7e,0x61,0x35,0xc9,0xb7},{0x56,0x7d,0x68,0x3e,0xc4,0xb9},
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{0x58,0x74,0x57,0x0f,0xe7,0x93},{0x5a,0x77,0x5e,0x04,0xea,0x9d},
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{0x5c,0x72,0x45,0x19,0xfd,0x8f},{0x5e,0x71,0x4c,0x12,0xf0,0x81},
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{0x60,0x50,0xab,0xcb,0x6b,0x3b},{0x62,0x53,0xa2,0xc0,0x66,0x35},
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{0x64,0x56,0xb9,0xdd,0x71,0x27},{0x66,0x55,0xb0,0xd6,0x7c,0x29},
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{0x68,0x5c,0x8f,0xe7,0x5f,0x03},{0x6a,0x5f,0x86,0xec,0x52,0x0d},
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{0x6c,0x5a,0x9d,0xf1,0x45,0x1f},{0x6e,0x59,0x94,0xfa,0x48,0x11},
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{0x70,0x48,0xe3,0x93,0x03,0x4b},{0x72,0x4b,0xea,0x98,0x0e,0x45},
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{0x74,0x4e,0xf1,0x85,0x19,0x57},{0x76,0x4d,0xf8,0x8e,0x14,0x59},
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{0x78,0x44,0xc7,0xbf,0x37,0x73},{0x7a,0x47,0xce,0xb4,0x3a,0x7d},
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{0x7c,0x42,0xd5,0xa9,0x2d,0x6f},{0x7e,0x41,0xdc,0xa2,0x20,0x61},
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{0x80,0xc0,0x76,0xf6,0x6d,0xad},{0x82,0xc3,0x7f,0xfd,0x60,0xa3},
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{0x84,0xc6,0x64,0xe0,0x77,0xb1},{0x86,0xc5,0x6d,0xeb,0x7a,0xbf},
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{0x88,0xcc,0x52,0xda,0x59,0x95},{0x8a,0xcf,0x5b,0xd1,0x54,0x9b},
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{0x8c,0xca,0x40,0xcc,0x43,0x89},{0x8e,0xc9,0x49,0xc7,0x4e,0x87},
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{0x90,0xd8,0x3e,0xae,0x05,0xdd},{0x92,0xdb,0x37,0xa5,0x08,0xd3},
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{0x94,0xde,0x2c,0xb8,0x1f,0xc1},{0x96,0xdd,0x25,0xb3,0x12,0xcf},
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{0x98,0xd4,0x1a,0x82,0x31,0xe5},{0x9a,0xd7,0x13,0x89,0x3c,0xeb},
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{0x9c,0xd2,0x08,0x94,0x2b,0xf9},{0x9e,0xd1,0x01,0x9f,0x26,0xf7},
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{0xa0,0xf0,0xe6,0x46,0xbd,0x4d},{0xa2,0xf3,0xef,0x4d,0xb0,0x43},
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{0xa4,0xf6,0xf4,0x50,0xa7,0x51},{0xa6,0xf5,0xfd,0x5b,0xaa,0x5f},
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{0xa8,0xfc,0xc2,0x6a,0x89,0x75},{0xaa,0xff,0xcb,0x61,0x84,0x7b},
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{0xac,0xfa,0xd0,0x7c,0x93,0x69},{0xae,0xf9,0xd9,0x77,0x9e,0x67},
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{0xb0,0xe8,0xae,0x1e,0xd5,0x3d},{0xb2,0xeb,0xa7,0x15,0xd8,0x33},
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{0xb4,0xee,0xbc,0x08,0xcf,0x21},{0xb6,0xed,0xb5,0x03,0xc2,0x2f},
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{0xb8,0xe4,0x8a,0x32,0xe1,0x05},{0xba,0xe7,0x83,0x39,0xec,0x0b},
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{0xbc,0xe2,0x98,0x24,0xfb,0x19},{0xbe,0xe1,0x91,0x2f,0xf6,0x17},
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{0xc0,0xa0,0x4d,0x8d,0xd6,0x76},{0xc2,0xa3,0x44,0x86,0xdb,0x78},
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{0xc4,0xa6,0x5f,0x9b,0xcc,0x6a},{0xc6,0xa5,0x56,0x90,0xc1,0x64},
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{0xc8,0xac,0x69,0xa1,0xe2,0x4e},{0xca,0xaf,0x60,0xaa,0xef,0x40},
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{0xcc,0xaa,0x7b,0xb7,0xf8,0x52},{0xce,0xa9,0x72,0xbc,0xf5,0x5c},
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{0xd0,0xb8,0x05,0xd5,0xbe,0x06},{0xd2,0xbb,0x0c,0xde,0xb3,0x08},
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{0xd4,0xbe,0x17,0xc3,0xa4,0x1a},{0xd6,0xbd,0x1e,0xc8,0xa9,0x14},
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{0xd8,0xb4,0x21,0xf9,0x8a,0x3e},{0xda,0xb7,0x28,0xf2,0x87,0x30},
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{0xdc,0xb2,0x33,0xef,0x90,0x22},{0xde,0xb1,0x3a,0xe4,0x9d,0x2c},
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{0xe0,0x90,0xdd,0x3d,0x06,0x96},{0xe2,0x93,0xd4,0x36,0x0b,0x98},
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{0xe4,0x96,0xcf,0x2b,0x1c,0x8a},{0xe6,0x95,0xc6,0x20,0x11,0x84},
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{0xe8,0x9c,0xf9,0x11,0x32,0xae},{0xea,0x9f,0xf0,0x1a,0x3f,0xa0},
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{0xec,0x9a,0xeb,0x07,0x28,0xb2},{0xee,0x99,0xe2,0x0c,0x25,0xbc},
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{0xf0,0x88,0x95,0x65,0x6e,0xe6},{0xf2,0x8b,0x9c,0x6e,0x63,0xe8},
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{0xf4,0x8e,0x87,0x73,0x74,0xfa},{0xf6,0x8d,0x8e,0x78,0x79,0xf4},
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{0xf8,0x84,0xb1,0x49,0x5a,0xde},{0xfa,0x87,0xb8,0x42,0x57,0xd0},
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{0xfc,0x82,0xa3,0x5f,0x40,0xc2},{0xfe,0x81,0xaa,0x54,0x4d,0xcc},
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{0x1b,0x9b,0xec,0xf7,0xda,0x41},{0x19,0x98,0xe5,0xfc,0xd7,0x4f},
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{0x1f,0x9d,0xfe,0xe1,0xc0,0x5d},{0x1d,0x9e,0xf7,0xea,0xcd,0x53},
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{0x13,0x97,0xc8,0xdb,0xee,0x79},{0x11,0x94,0xc1,0xd0,0xe3,0x77},
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{0x17,0x91,0xda,0xcd,0xf4,0x65},{0x15,0x92,0xd3,0xc6,0xf9,0x6b},
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{0x0b,0x83,0xa4,0xaf,0xb2,0x31},{0x09,0x80,0xad,0xa4,0xbf,0x3f},
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{0x0f,0x85,0xb6,0xb9,0xa8,0x2d},{0x0d,0x86,0xbf,0xb2,0xa5,0x23},
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{0x03,0x8f,0x80,0x83,0x86,0x09},{0x01,0x8c,0x89,0x88,0x8b,0x07},
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{0x07,0x89,0x92,0x95,0x9c,0x15},{0x05,0x8a,0x9b,0x9e,0x91,0x1b},
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{0x3b,0xab,0x7c,0x47,0x0a,0xa1},{0x39,0xa8,0x75,0x4c,0x07,0xaf},
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{0x3f,0xad,0x6e,0x51,0x10,0xbd},{0x3d,0xae,0x67,0x5a,0x1d,0xb3},
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|
{0x33,0xa7,0x58,0x6b,0x3e,0x99},{0x31,0xa4,0x51,0x60,0x33,0x97},
|
|
{0x37,0xa1,0x4a,0x7d,0x24,0x85},{0x35,0xa2,0x43,0x76,0x29,0x8b},
|
|
{0x2b,0xb3,0x34,0x1f,0x62,0xd1},{0x29,0xb0,0x3d,0x14,0x6f,0xdf},
|
|
{0x2f,0xb5,0x26,0x09,0x78,0xcd},{0x2d,0xb6,0x2f,0x02,0x75,0xc3},
|
|
{0x23,0xbf,0x10,0x33,0x56,0xe9},{0x21,0xbc,0x19,0x38,0x5b,0xe7},
|
|
{0x27,0xb9,0x02,0x25,0x4c,0xf5},{0x25,0xba,0x0b,0x2e,0x41,0xfb},
|
|
{0x5b,0xfb,0xd7,0x8c,0x61,0x9a},{0x59,0xf8,0xde,0x87,0x6c,0x94},
|
|
{0x5f,0xfd,0xc5,0x9a,0x7b,0x86},{0x5d,0xfe,0xcc,0x91,0x76,0x88},
|
|
{0x53,0xf7,0xf3,0xa0,0x55,0xa2},{0x51,0xf4,0xfa,0xab,0x58,0xac},
|
|
{0x57,0xf1,0xe1,0xb6,0x4f,0xbe},{0x55,0xf2,0xe8,0xbd,0x42,0xb0},
|
|
{0x4b,0xe3,0x9f,0xd4,0x09,0xea},{0x49,0xe0,0x96,0xdf,0x04,0xe4},
|
|
{0x4f,0xe5,0x8d,0xc2,0x13,0xf6},{0x4d,0xe6,0x84,0xc9,0x1e,0xf8},
|
|
{0x43,0xef,0xbb,0xf8,0x3d,0xd2},{0x41,0xec,0xb2,0xf3,0x30,0xdc},
|
|
{0x47,0xe9,0xa9,0xee,0x27,0xce},{0x45,0xea,0xa0,0xe5,0x2a,0xc0},
|
|
{0x7b,0xcb,0x47,0x3c,0xb1,0x7a},{0x79,0xc8,0x4e,0x37,0xbc,0x74},
|
|
{0x7f,0xcd,0x55,0x2a,0xab,0x66},{0x7d,0xce,0x5c,0x21,0xa6,0x68},
|
|
{0x73,0xc7,0x63,0x10,0x85,0x42},{0x71,0xc4,0x6a,0x1b,0x88,0x4c},
|
|
{0x77,0xc1,0x71,0x06,0x9f,0x5e},{0x75,0xc2,0x78,0x0d,0x92,0x50},
|
|
{0x6b,0xd3,0x0f,0x64,0xd9,0x0a},{0x69,0xd0,0x06,0x6f,0xd4,0x04},
|
|
{0x6f,0xd5,0x1d,0x72,0xc3,0x16},{0x6d,0xd6,0x14,0x79,0xce,0x18},
|
|
{0x63,0xdf,0x2b,0x48,0xed,0x32},{0x61,0xdc,0x22,0x43,0xe0,0x3c},
|
|
{0x67,0xd9,0x39,0x5e,0xf7,0x2e},{0x65,0xda,0x30,0x55,0xfa,0x20},
|
|
{0x9b,0x5b,0x9a,0x01,0xb7,0xec},{0x99,0x58,0x93,0x0a,0xba,0xe2},
|
|
{0x9f,0x5d,0x88,0x17,0xad,0xf0},{0x9d,0x5e,0x81,0x1c,0xa0,0xfe},
|
|
{0x93,0x57,0xbe,0x2d,0x83,0xd4},{0x91,0x54,0xb7,0x26,0x8e,0xda},
|
|
{0x97,0x51,0xac,0x3b,0x99,0xc8},{0x95,0x52,0xa5,0x30,0x94,0xc6},
|
|
{0x8b,0x43,0xd2,0x59,0xdf,0x9c},{0x89,0x40,0xdb,0x52,0xd2,0x92},
|
|
{0x8f,0x45,0xc0,0x4f,0xc5,0x80},{0x8d,0x46,0xc9,0x44,0xc8,0x8e},
|
|
{0x83,0x4f,0xf6,0x75,0xeb,0xa4},{0x81,0x4c,0xff,0x7e,0xe6,0xaa},
|
|
{0x87,0x49,0xe4,0x63,0xf1,0xb8},{0x85,0x4a,0xed,0x68,0xfc,0xb6},
|
|
{0xbb,0x6b,0x0a,0xb1,0x67,0x0c},{0xb9,0x68,0x03,0xba,0x6a,0x02},
|
|
{0xbf,0x6d,0x18,0xa7,0x7d,0x10},{0xbd,0x6e,0x11,0xac,0x70,0x1e},
|
|
{0xb3,0x67,0x2e,0x9d,0x53,0x34},{0xb1,0x64,0x27,0x96,0x5e,0x3a},
|
|
{0xb7,0x61,0x3c,0x8b,0x49,0x28},{0xb5,0x62,0x35,0x80,0x44,0x26},
|
|
{0xab,0x73,0x42,0xe9,0x0f,0x7c},{0xa9,0x70,0x4b,0xe2,0x02,0x72},
|
|
{0xaf,0x75,0x50,0xff,0x15,0x60},{0xad,0x76,0x59,0xf4,0x18,0x6e},
|
|
{0xa3,0x7f,0x66,0xc5,0x3b,0x44},{0xa1,0x7c,0x6f,0xce,0x36,0x4a},
|
|
{0xa7,0x79,0x74,0xd3,0x21,0x58},{0xa5,0x7a,0x7d,0xd8,0x2c,0x56},
|
|
{0xdb,0x3b,0xa1,0x7a,0x0c,0x37},{0xd9,0x38,0xa8,0x71,0x01,0x39},
|
|
{0xdf,0x3d,0xb3,0x6c,0x16,0x2b},{0xdd,0x3e,0xba,0x67,0x1b,0x25},
|
|
{0xd3,0x37,0x85,0x56,0x38,0x0f},{0xd1,0x34,0x8c,0x5d,0x35,0x01},
|
|
{0xd7,0x31,0x97,0x40,0x22,0x13},{0xd5,0x32,0x9e,0x4b,0x2f,0x1d},
|
|
{0xcb,0x23,0xe9,0x22,0x64,0x47},{0xc9,0x20,0xe0,0x29,0x69,0x49},
|
|
{0xcf,0x25,0xfb,0x34,0x7e,0x5b},{0xcd,0x26,0xf2,0x3f,0x73,0x55},
|
|
{0xc3,0x2f,0xcd,0x0e,0x50,0x7f},{0xc1,0x2c,0xc4,0x05,0x5d,0x71},
|
|
{0xc7,0x29,0xdf,0x18,0x4a,0x63},{0xc5,0x2a,0xd6,0x13,0x47,0x6d},
|
|
{0xfb,0x0b,0x31,0xca,0xdc,0xd7},{0xf9,0x08,0x38,0xc1,0xd1,0xd9},
|
|
{0xff,0x0d,0x23,0xdc,0xc6,0xcb},{0xfd,0x0e,0x2a,0xd7,0xcb,0xc5},
|
|
{0xf3,0x07,0x15,0xe6,0xe8,0xef},{0xf1,0x04,0x1c,0xed,0xe5,0xe1},
|
|
{0xf7,0x01,0x07,0xf0,0xf2,0xf3},{0xf5,0x02,0x0e,0xfb,0xff,0xfd},
|
|
{0xeb,0x13,0x79,0x92,0xb4,0xa7},{0xe9,0x10,0x70,0x99,0xb9,0xa9},
|
|
{0xef,0x15,0x6b,0x84,0xae,0xbb},{0xed,0x16,0x62,0x8f,0xa3,0xb5},
|
|
{0xe3,0x1f,0x5d,0xbe,0x80,0x9f},{0xe1,0x1c,0x54,0xb5,0x8d,0x91},
|
|
{0xe7,0x19,0x4f,0xa8,0x9a,0x83},{0xe5,0x1a,0x46,0xa3,0x97,0x8d}
|
|
};
|
|
|
|
/*********************** FUNCTION DEFINITIONS ***********************/
|
|
// XORs the in and out buffers, storing the result in out. Length is in bytes.
|
|
void xor_buf(const BYTE in[], BYTE out[], size_t len)
|
|
{
|
|
size_t idx;
|
|
|
|
for (idx = 0; idx < len; idx++)
|
|
out[idx] ^= in[idx];
|
|
}
|
|
|
|
/*******************
|
|
* AES - CBC
|
|
*******************/
|
|
int aes_encrypt_cbc(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
|
|
{
|
|
BYTE buf_in[AES_BLOCK_SIZE], buf_out[AES_BLOCK_SIZE];
|
|
int blocks, idx;
|
|
|
|
if (in_len % AES_BLOCK_SIZE != 0)
|
|
return(FALSE);
|
|
|
|
blocks = in_len / AES_BLOCK_SIZE;
|
|
|
|
memcpy(buf_out, iv, AES_BLOCK_SIZE);
|
|
|
|
for (idx = 0; idx < blocks; idx++) {
|
|
memcpy(buf_in, &in[idx * AES_BLOCK_SIZE], AES_BLOCK_SIZE);
|
|
xor_buf(buf_out, buf_in, AES_BLOCK_SIZE);
|
|
aes_encrypt(buf_in, buf_out, key, keysize);
|
|
memcpy(&out[idx * AES_BLOCK_SIZE], buf_out, AES_BLOCK_SIZE);
|
|
}
|
|
|
|
return(TRUE);
|
|
}
|
|
|
|
int aes_encrypt_cbc_mac(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
|
|
{
|
|
BYTE buf_in[AES_BLOCK_SIZE], buf_out[AES_BLOCK_SIZE];
|
|
int blocks, idx;
|
|
|
|
if (in_len % AES_BLOCK_SIZE != 0)
|
|
return(FALSE);
|
|
|
|
blocks = in_len / AES_BLOCK_SIZE;
|
|
|
|
memcpy(buf_out, iv, AES_BLOCK_SIZE);
|
|
|
|
for (idx = 0; idx < blocks; idx++) {
|
|
memcpy(buf_in, &in[idx * AES_BLOCK_SIZE], AES_BLOCK_SIZE);
|
|
xor_buf(buf_out, buf_in, AES_BLOCK_SIZE);
|
|
aes_encrypt(buf_in, buf_out, key, keysize);
|
|
// Do not output all encrypted blocks.
|
|
}
|
|
|
|
memcpy(out, buf_out, AES_BLOCK_SIZE); // Only output the last block.
|
|
|
|
return(TRUE);
|
|
}
|
|
|
|
// No need for an aes_decrypt_cbc() for just CCM.
|
|
|
|
/*******************
|
|
* AES - CTR
|
|
*******************/
|
|
void increment_iv(BYTE iv[], int counter_size)
|
|
{
|
|
int idx;
|
|
|
|
// Use counter_size bytes at the end of the IV as the big-endian integer to increment.
|
|
for (idx = AES_BLOCK_SIZE - 1; idx >= AES_BLOCK_SIZE - counter_size; idx--) {
|
|
iv[idx]++;
|
|
if (iv[idx] != 0 || idx == AES_BLOCK_SIZE - counter_size)
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Performs the encryption in-place, the input and output buffers may be the same.
|
|
// Input may be an arbitrary length (in bytes).
|
|
void aes_encrypt_ctr(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
|
|
{
|
|
size_t idx = 0, last_block_length;
|
|
BYTE iv_buf[AES_BLOCK_SIZE], out_buf[AES_BLOCK_SIZE];
|
|
|
|
if (in != out)
|
|
memcpy(out, in, in_len);
|
|
|
|
memcpy(iv_buf, iv, AES_BLOCK_SIZE);
|
|
last_block_length = in_len - AES_BLOCK_SIZE;
|
|
|
|
if (in_len > AES_BLOCK_SIZE) {
|
|
for (idx = 0; idx < last_block_length; idx += AES_BLOCK_SIZE) {
|
|
aes_encrypt(iv_buf, out_buf, key, keysize);
|
|
xor_buf(out_buf, &out[idx], AES_BLOCK_SIZE);
|
|
increment_iv(iv_buf, AES_BLOCK_SIZE);
|
|
}
|
|
}
|
|
|
|
aes_encrypt(iv_buf, out_buf, key, keysize);
|
|
xor_buf(out_buf, &out[idx], in_len - idx); // Use the Most Significant bytes.
|
|
}
|
|
|
|
void aes_decrypt_ctr(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
|
|
{
|
|
// CTR encryption is its own inverse function.
|
|
aes_encrypt_ctr(in, in_len, out, key, keysize, iv);
|
|
}
|
|
|
|
/*******************
|
|
* AES - CCM
|
|
*******************/
|
|
// out_len = payload_len + assoc_len
|
|
int aes_encrypt_ccm(const BYTE payload[], WORD payload_len, const BYTE assoc[], unsigned short assoc_len,
|
|
const BYTE nonce[], unsigned short nonce_len, BYTE out[], WORD *out_len,
|
|
WORD mac_len, const BYTE key_str[], int keysize)
|
|
{
|
|
BYTE temp_iv[AES_BLOCK_SIZE], counter[AES_BLOCK_SIZE], mac[16], *buf;
|
|
int end_of_buf, payload_len_store_size;
|
|
WORD key[60];
|
|
|
|
if (mac_len != 4 && mac_len != 6 && mac_len != 8 && mac_len != 10 &&
|
|
mac_len != 12 && mac_len != 14 && mac_len != 16)
|
|
return(FALSE);
|
|
|
|
if (nonce_len < 7 || nonce_len > 13)
|
|
return(FALSE);
|
|
|
|
if (assoc_len > 32768 /* = 2^15 */)
|
|
return(FALSE);
|
|
|
|
buf = (BYTE*)malloc(payload_len + assoc_len + 48 /*Round both payload and associated data up a block size and add an extra block.*/);
|
|
if (! buf)
|
|
return(FALSE);
|
|
|
|
// Prepare the key for usage.
|
|
aes_key_setup(key_str, key, keysize);
|
|
|
|
// Format the first block of the formatted data.
|
|
payload_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
|
|
ccm_prepare_first_format_blk(buf, assoc_len, payload_len, payload_len_store_size, mac_len, nonce, nonce_len);
|
|
end_of_buf = AES_BLOCK_SIZE;
|
|
|
|
// Format the Associated Data, aka, assoc[].
|
|
ccm_format_assoc_data(buf, &end_of_buf, assoc, assoc_len);
|
|
|
|
// Format the Payload, aka payload[].
|
|
ccm_format_payload_data(buf, &end_of_buf, payload, payload_len);
|
|
|
|
// Create the first counter block.
|
|
ccm_prepare_first_ctr_blk(counter, nonce, nonce_len, payload_len_store_size);
|
|
|
|
// Perform the CBC operation with an IV of zeros on the formatted buffer to calculate the MAC.
|
|
memset(temp_iv, 0, AES_BLOCK_SIZE);
|
|
aes_encrypt_cbc_mac(buf, end_of_buf, mac, key, keysize, temp_iv);
|
|
|
|
// Copy the Payload and MAC to the output buffer.
|
|
memcpy(out, payload, payload_len);
|
|
memcpy(&out[payload_len], mac, mac_len);
|
|
|
|
// Encrypt the Payload with CTR mode with a counter starting at 1.
|
|
memcpy(temp_iv, counter, AES_BLOCK_SIZE);
|
|
increment_iv(temp_iv, AES_BLOCK_SIZE - 1 - mac_len); // Last argument is the byte size of the counting portion of the counter block. /*BUG?*/
|
|
aes_encrypt_ctr(out, payload_len, out, key, keysize, temp_iv);
|
|
|
|
// Encrypt the MAC with CTR mode with a counter starting at 0.
|
|
aes_encrypt_ctr(&out[payload_len], mac_len, &out[payload_len], key, keysize, counter);
|
|
|
|
free(buf);
|
|
*out_len = payload_len + mac_len;
|
|
|
|
return(TRUE);
|
|
}
|
|
|
|
// plaintext_len = ciphertext_len - mac_len
|
|
// Needs a flag for whether the MAC matches.
|
|
int aes_decrypt_ccm(const BYTE ciphertext[], WORD ciphertext_len, const BYTE assoc[], unsigned short assoc_len,
|
|
const BYTE nonce[], unsigned short nonce_len, BYTE plaintext[], WORD *plaintext_len,
|
|
WORD mac_len, int *mac_auth, const BYTE key_str[], int keysize)
|
|
{
|
|
BYTE temp_iv[AES_BLOCK_SIZE], counter[AES_BLOCK_SIZE], mac[16], mac_buf[16], *buf;
|
|
int end_of_buf, plaintext_len_store_size;
|
|
WORD key[60];
|
|
|
|
if (ciphertext_len <= mac_len)
|
|
return(FALSE);
|
|
|
|
buf = (BYTE*)malloc(assoc_len + ciphertext_len /*ciphertext_len = plaintext_len + mac_len*/ + 48);
|
|
if (! buf)
|
|
return(FALSE);
|
|
|
|
// Prepare the key for usage.
|
|
aes_key_setup(key_str, key, keysize);
|
|
|
|
// Copy the plaintext and MAC to the output buffers.
|
|
*plaintext_len = ciphertext_len - mac_len;
|
|
plaintext_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
|
|
memcpy(plaintext, ciphertext, *plaintext_len);
|
|
memcpy(mac, &ciphertext[*plaintext_len], mac_len);
|
|
|
|
// Prepare the first counter block for use in decryption.
|
|
ccm_prepare_first_ctr_blk(counter, nonce, nonce_len, plaintext_len_store_size);
|
|
|
|
// Decrypt the Payload with CTR mode with a counter starting at 1.
|
|
memcpy(temp_iv, counter, AES_BLOCK_SIZE);
|
|
increment_iv(temp_iv, AES_BLOCK_SIZE - 1 - mac_len); // (AES_BLOCK_SIZE - 1 - mac_len) is the byte size of the counting portion of the counter block.
|
|
aes_decrypt_ctr(plaintext, *plaintext_len, plaintext, key, keysize, temp_iv);
|
|
|
|
// Setting mac_auth to NULL disables the authentication check.
|
|
if (mac_auth != NULL) {
|
|
// Decrypt the MAC with CTR mode with a counter starting at 0.
|
|
aes_decrypt_ctr(mac, mac_len, mac, key, keysize, counter);
|
|
|
|
// Format the first block of the formatted data.
|
|
plaintext_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
|
|
ccm_prepare_first_format_blk(buf, assoc_len, *plaintext_len, plaintext_len_store_size, mac_len, nonce, nonce_len);
|
|
end_of_buf = AES_BLOCK_SIZE;
|
|
|
|
// Format the Associated Data into the authentication buffer.
|
|
ccm_format_assoc_data(buf, &end_of_buf, assoc, assoc_len);
|
|
|
|
// Format the Payload into the authentication buffer.
|
|
ccm_format_payload_data(buf, &end_of_buf, plaintext, *plaintext_len);
|
|
|
|
// Perform the CBC operation with an IV of zeros on the formatted buffer to calculate the MAC.
|
|
memset(temp_iv, 0, AES_BLOCK_SIZE);
|
|
aes_encrypt_cbc_mac(buf, end_of_buf, mac_buf, key, keysize, temp_iv);
|
|
|
|
// Compare the calculated MAC against the MAC embedded in the ciphertext to see if they are the same.
|
|
if (! memcmp(mac, mac_buf, mac_len)) {
|
|
*mac_auth = TRUE;
|
|
}
|
|
else {
|
|
*mac_auth = FALSE;
|
|
memset(plaintext, 0, *plaintext_len);
|
|
}
|
|
}
|
|
|
|
free(buf);
|
|
|
|
return(TRUE);
|
|
}
|
|
|
|
// Creates the first counter block. First byte is flags, then the nonce, then the incremented part.
|
|
void ccm_prepare_first_ctr_blk(BYTE counter[], const BYTE nonce[], int nonce_len, int payload_len_store_size)
|
|
{
|
|
memset(counter, 0, AES_BLOCK_SIZE);
|
|
counter[0] = (payload_len_store_size - 1) & 0x07;
|
|
memcpy(&counter[1], nonce, nonce_len);
|
|
}
|
|
|
|
void ccm_prepare_first_format_blk(BYTE buf[], int assoc_len, int payload_len, int payload_len_store_size, int mac_len, const BYTE nonce[], int nonce_len)
|
|
{
|
|
// Set the flags for the first byte of the first block.
|
|
buf[0] = ((((mac_len - 2) / 2) & 0x07) << 3) | ((payload_len_store_size - 1) & 0x07);
|
|
if (assoc_len > 0)
|
|
buf[0] += 0x40;
|
|
// Format the rest of the first block, storing the nonce and the size of the payload.
|
|
memcpy(&buf[1], nonce, nonce_len);
|
|
memset(&buf[1 + nonce_len], 0, AES_BLOCK_SIZE - 1 - nonce_len);
|
|
buf[15] = payload_len & 0x000000FF;
|
|
buf[14] = (payload_len >> 8) & 0x000000FF;
|
|
}
|
|
|
|
void ccm_format_assoc_data(BYTE buf[], int *end_of_buf, const BYTE assoc[], int assoc_len)
|
|
{
|
|
int pad;
|
|
|
|
buf[*end_of_buf + 1] = assoc_len & 0x00FF;
|
|
buf[*end_of_buf] = (assoc_len >> 8) & 0x00FF;
|
|
*end_of_buf += 2;
|
|
memcpy(&buf[*end_of_buf], assoc, assoc_len);
|
|
*end_of_buf += assoc_len;
|
|
pad = AES_BLOCK_SIZE - (*end_of_buf % AES_BLOCK_SIZE); /*BUG?*/
|
|
memset(&buf[*end_of_buf], 0, pad);
|
|
*end_of_buf += pad;
|
|
}
|
|
|
|
void ccm_format_payload_data(BYTE buf[], int *end_of_buf, const BYTE payload[], int payload_len)
|
|
{
|
|
int pad;
|
|
|
|
memcpy(&buf[*end_of_buf], payload, payload_len);
|
|
*end_of_buf += payload_len;
|
|
pad = *end_of_buf % AES_BLOCK_SIZE;
|
|
if (pad != 0)
|
|
pad = AES_BLOCK_SIZE - pad;
|
|
memset(&buf[*end_of_buf], 0, pad);
|
|
*end_of_buf += pad;
|
|
}
|
|
|
|
/*******************
|
|
* AES
|
|
*******************/
|
|
/////////////////
|
|
// KEY EXPANSION
|
|
/////////////////
|
|
|
|
// Substitutes a word using the AES S-Box.
|
|
WORD SubWord(WORD word)
|
|
{
|
|
unsigned int result;
|
|
|
|
result = (int)aes_sbox[(word >> 4) & 0x0000000F][word & 0x0000000F];
|
|
result += (int)aes_sbox[(word >> 12) & 0x0000000F][(word >> 8) & 0x0000000F] << 8;
|
|
result += (int)aes_sbox[(word >> 20) & 0x0000000F][(word >> 16) & 0x0000000F] << 16;
|
|
result += (int)aes_sbox[(word >> 28) & 0x0000000F][(word >> 24) & 0x0000000F] << 24;
|
|
return(result);
|
|
}
|
|
|
|
// Performs the action of generating the keys that will be used in every round of
|
|
// encryption. "key" is the user-supplied input key, "w" is the output key schedule,
|
|
// "keysize" is the length in bits of "key", must be 128, 192, or 256.
|
|
void aes_key_setup(const BYTE key[], WORD w[], int keysize)
|
|
{
|
|
int Nb=4,Nr,Nk,idx;
|
|
WORD temp,Rcon[]={0x01000000,0x02000000,0x04000000,0x08000000,0x10000000,0x20000000,
|
|
0x40000000,0x80000000,0x1b000000,0x36000000,0x6c000000,0xd8000000,
|
|
0xab000000,0x4d000000,0x9a000000};
|
|
|
|
switch (keysize) {
|
|
case 128: Nr = 10; Nk = 4; break;
|
|
case 192: Nr = 12; Nk = 6; break;
|
|
case 256: Nr = 14; Nk = 8; break;
|
|
default: return;
|
|
}
|
|
|
|
for (idx=0; idx < Nk; ++idx) {
|
|
w[idx] = ((key[4 * idx]) << 24) | ((key[4 * idx + 1]) << 16) |
|
|
((key[4 * idx + 2]) << 8) | ((key[4 * idx + 3]));
|
|
}
|
|
|
|
for (idx = Nk; idx < Nb * (Nr+1); ++idx) {
|
|
temp = w[idx - 1];
|
|
if ((idx % Nk) == 0)
|
|
temp = SubWord(KE_ROTWORD(temp)) ^ Rcon[(idx-1)/Nk];
|
|
else if (Nk > 6 && (idx % Nk) == 4)
|
|
temp = SubWord(temp);
|
|
w[idx] = w[idx-Nk] ^ temp;
|
|
}
|
|
}
|
|
|
|
/////////////////
|
|
// ADD ROUND KEY
|
|
/////////////////
|
|
|
|
// Performs the AddRoundKey step. Each round has its own pre-generated 16-byte key in the
|
|
// form of 4 integers (the "w" array). Each integer is XOR'd by one column of the state.
|
|
// Also performs the job of InvAddRoundKey(); since the function is a simple XOR process,
|
|
// it is its own inverse.
|
|
void AddRoundKey(BYTE state[][4], const WORD w[])
|
|
{
|
|
BYTE subkey[4];
|
|
|
|
// memcpy(subkey,&w[idx],4); // Not accurate for big endian machines
|
|
// Subkey 1
|
|
subkey[0] = w[0] >> 24;
|
|
subkey[1] = w[0] >> 16;
|
|
subkey[2] = w[0] >> 8;
|
|
subkey[3] = w[0];
|
|
state[0][0] ^= subkey[0];
|
|
state[1][0] ^= subkey[1];
|
|
state[2][0] ^= subkey[2];
|
|
state[3][0] ^= subkey[3];
|
|
// Subkey 2
|
|
subkey[0] = w[1] >> 24;
|
|
subkey[1] = w[1] >> 16;
|
|
subkey[2] = w[1] >> 8;
|
|
subkey[3] = w[1];
|
|
state[0][1] ^= subkey[0];
|
|
state[1][1] ^= subkey[1];
|
|
state[2][1] ^= subkey[2];
|
|
state[3][1] ^= subkey[3];
|
|
// Subkey 3
|
|
subkey[0] = w[2] >> 24;
|
|
subkey[1] = w[2] >> 16;
|
|
subkey[2] = w[2] >> 8;
|
|
subkey[3] = w[2];
|
|
state[0][2] ^= subkey[0];
|
|
state[1][2] ^= subkey[1];
|
|
state[2][2] ^= subkey[2];
|
|
state[3][2] ^= subkey[3];
|
|
// Subkey 4
|
|
subkey[0] = w[3] >> 24;
|
|
subkey[1] = w[3] >> 16;
|
|
subkey[2] = w[3] >> 8;
|
|
subkey[3] = w[3];
|
|
state[0][3] ^= subkey[0];
|
|
state[1][3] ^= subkey[1];
|
|
state[2][3] ^= subkey[2];
|
|
state[3][3] ^= subkey[3];
|
|
}
|
|
|
|
/////////////////
|
|
// (Inv)SubBytes
|
|
/////////////////
|
|
|
|
// Performs the SubBytes step. All bytes in the state are substituted with a
|
|
// pre-calculated value from a lookup table.
|
|
void SubBytes(BYTE state[][4])
|
|
{
|
|
state[0][0] = aes_sbox[state[0][0] >> 4][state[0][0] & 0x0F];
|
|
state[0][1] = aes_sbox[state[0][1] >> 4][state[0][1] & 0x0F];
|
|
state[0][2] = aes_sbox[state[0][2] >> 4][state[0][2] & 0x0F];
|
|
state[0][3] = aes_sbox[state[0][3] >> 4][state[0][3] & 0x0F];
|
|
state[1][0] = aes_sbox[state[1][0] >> 4][state[1][0] & 0x0F];
|
|
state[1][1] = aes_sbox[state[1][1] >> 4][state[1][1] & 0x0F];
|
|
state[1][2] = aes_sbox[state[1][2] >> 4][state[1][2] & 0x0F];
|
|
state[1][3] = aes_sbox[state[1][3] >> 4][state[1][3] & 0x0F];
|
|
state[2][0] = aes_sbox[state[2][0] >> 4][state[2][0] & 0x0F];
|
|
state[2][1] = aes_sbox[state[2][1] >> 4][state[2][1] & 0x0F];
|
|
state[2][2] = aes_sbox[state[2][2] >> 4][state[2][2] & 0x0F];
|
|
state[2][3] = aes_sbox[state[2][3] >> 4][state[2][3] & 0x0F];
|
|
state[3][0] = aes_sbox[state[3][0] >> 4][state[3][0] & 0x0F];
|
|
state[3][1] = aes_sbox[state[3][1] >> 4][state[3][1] & 0x0F];
|
|
state[3][2] = aes_sbox[state[3][2] >> 4][state[3][2] & 0x0F];
|
|
state[3][3] = aes_sbox[state[3][3] >> 4][state[3][3] & 0x0F];
|
|
}
|
|
|
|
void InvSubBytes(BYTE state[][4])
|
|
{
|
|
state[0][0] = aes_invsbox[state[0][0] >> 4][state[0][0] & 0x0F];
|
|
state[0][1] = aes_invsbox[state[0][1] >> 4][state[0][1] & 0x0F];
|
|
state[0][2] = aes_invsbox[state[0][2] >> 4][state[0][2] & 0x0F];
|
|
state[0][3] = aes_invsbox[state[0][3] >> 4][state[0][3] & 0x0F];
|
|
state[1][0] = aes_invsbox[state[1][0] >> 4][state[1][0] & 0x0F];
|
|
state[1][1] = aes_invsbox[state[1][1] >> 4][state[1][1] & 0x0F];
|
|
state[1][2] = aes_invsbox[state[1][2] >> 4][state[1][2] & 0x0F];
|
|
state[1][3] = aes_invsbox[state[1][3] >> 4][state[1][3] & 0x0F];
|
|
state[2][0] = aes_invsbox[state[2][0] >> 4][state[2][0] & 0x0F];
|
|
state[2][1] = aes_invsbox[state[2][1] >> 4][state[2][1] & 0x0F];
|
|
state[2][2] = aes_invsbox[state[2][2] >> 4][state[2][2] & 0x0F];
|
|
state[2][3] = aes_invsbox[state[2][3] >> 4][state[2][3] & 0x0F];
|
|
state[3][0] = aes_invsbox[state[3][0] >> 4][state[3][0] & 0x0F];
|
|
state[3][1] = aes_invsbox[state[3][1] >> 4][state[3][1] & 0x0F];
|
|
state[3][2] = aes_invsbox[state[3][2] >> 4][state[3][2] & 0x0F];
|
|
state[3][3] = aes_invsbox[state[3][3] >> 4][state[3][3] & 0x0F];
|
|
}
|
|
|
|
/////////////////
|
|
// (Inv)ShiftRows
|
|
/////////////////
|
|
|
|
// Performs the ShiftRows step. All rows are shifted cylindrically to the left.
|
|
void ShiftRows(BYTE state[][4])
|
|
{
|
|
int t;
|
|
|
|
// Shift left by 1
|
|
t = state[1][0];
|
|
state[1][0] = state[1][1];
|
|
state[1][1] = state[1][2];
|
|
state[1][2] = state[1][3];
|
|
state[1][3] = t;
|
|
// Shift left by 2
|
|
t = state[2][0];
|
|
state[2][0] = state[2][2];
|
|
state[2][2] = t;
|
|
t = state[2][1];
|
|
state[2][1] = state[2][3];
|
|
state[2][3] = t;
|
|
// Shift left by 3
|
|
t = state[3][0];
|
|
state[3][0] = state[3][3];
|
|
state[3][3] = state[3][2];
|
|
state[3][2] = state[3][1];
|
|
state[3][1] = t;
|
|
}
|
|
|
|
// All rows are shifted cylindrically to the right.
|
|
void InvShiftRows(BYTE state[][4])
|
|
{
|
|
int t;
|
|
|
|
// Shift right by 1
|
|
t = state[1][3];
|
|
state[1][3] = state[1][2];
|
|
state[1][2] = state[1][1];
|
|
state[1][1] = state[1][0];
|
|
state[1][0] = t;
|
|
// Shift right by 2
|
|
t = state[2][3];
|
|
state[2][3] = state[2][1];
|
|
state[2][1] = t;
|
|
t = state[2][2];
|
|
state[2][2] = state[2][0];
|
|
state[2][0] = t;
|
|
// Shift right by 3
|
|
t = state[3][3];
|
|
state[3][3] = state[3][0];
|
|
state[3][0] = state[3][1];
|
|
state[3][1] = state[3][2];
|
|
state[3][2] = t;
|
|
}
|
|
|
|
/////////////////
|
|
// (Inv)MixColumns
|
|
/////////////////
|
|
|
|
// Performs the MixColums step. The state is multiplied by itself using matrix
|
|
// multiplication in a Galios Field 2^8. All multiplication is pre-computed in a table.
|
|
// Addition is equivilent to XOR. (Must always make a copy of the column as the original
|
|
// values will be destoyed.)
|
|
void MixColumns(BYTE state[][4])
|
|
{
|
|
BYTE col[4];
|
|
|
|
// Column 1
|
|
col[0] = state[0][0];
|
|
col[1] = state[1][0];
|
|
col[2] = state[2][0];
|
|
col[3] = state[3][0];
|
|
state[0][0] = gf_mul[col[0]][0];
|
|
state[0][0] ^= gf_mul[col[1]][1];
|
|
state[0][0] ^= col[2];
|
|
state[0][0] ^= col[3];
|
|
state[1][0] = col[0];
|
|
state[1][0] ^= gf_mul[col[1]][0];
|
|
state[1][0] ^= gf_mul[col[2]][1];
|
|
state[1][0] ^= col[3];
|
|
state[2][0] = col[0];
|
|
state[2][0] ^= col[1];
|
|
state[2][0] ^= gf_mul[col[2]][0];
|
|
state[2][0] ^= gf_mul[col[3]][1];
|
|
state[3][0] = gf_mul[col[0]][1];
|
|
state[3][0] ^= col[1];
|
|
state[3][0] ^= col[2];
|
|
state[3][0] ^= gf_mul[col[3]][0];
|
|
// Column 2
|
|
col[0] = state[0][1];
|
|
col[1] = state[1][1];
|
|
col[2] = state[2][1];
|
|
col[3] = state[3][1];
|
|
state[0][1] = gf_mul[col[0]][0];
|
|
state[0][1] ^= gf_mul[col[1]][1];
|
|
state[0][1] ^= col[2];
|
|
state[0][1] ^= col[3];
|
|
state[1][1] = col[0];
|
|
state[1][1] ^= gf_mul[col[1]][0];
|
|
state[1][1] ^= gf_mul[col[2]][1];
|
|
state[1][1] ^= col[3];
|
|
state[2][1] = col[0];
|
|
state[2][1] ^= col[1];
|
|
state[2][1] ^= gf_mul[col[2]][0];
|
|
state[2][1] ^= gf_mul[col[3]][1];
|
|
state[3][1] = gf_mul[col[0]][1];
|
|
state[3][1] ^= col[1];
|
|
state[3][1] ^= col[2];
|
|
state[3][1] ^= gf_mul[col[3]][0];
|
|
// Column 3
|
|
col[0] = state[0][2];
|
|
col[1] = state[1][2];
|
|
col[2] = state[2][2];
|
|
col[3] = state[3][2];
|
|
state[0][2] = gf_mul[col[0]][0];
|
|
state[0][2] ^= gf_mul[col[1]][1];
|
|
state[0][2] ^= col[2];
|
|
state[0][2] ^= col[3];
|
|
state[1][2] = col[0];
|
|
state[1][2] ^= gf_mul[col[1]][0];
|
|
state[1][2] ^= gf_mul[col[2]][1];
|
|
state[1][2] ^= col[3];
|
|
state[2][2] = col[0];
|
|
state[2][2] ^= col[1];
|
|
state[2][2] ^= gf_mul[col[2]][0];
|
|
state[2][2] ^= gf_mul[col[3]][1];
|
|
state[3][2] = gf_mul[col[0]][1];
|
|
state[3][2] ^= col[1];
|
|
state[3][2] ^= col[2];
|
|
state[3][2] ^= gf_mul[col[3]][0];
|
|
// Column 4
|
|
col[0] = state[0][3];
|
|
col[1] = state[1][3];
|
|
col[2] = state[2][3];
|
|
col[3] = state[3][3];
|
|
state[0][3] = gf_mul[col[0]][0];
|
|
state[0][3] ^= gf_mul[col[1]][1];
|
|
state[0][3] ^= col[2];
|
|
state[0][3] ^= col[3];
|
|
state[1][3] = col[0];
|
|
state[1][3] ^= gf_mul[col[1]][0];
|
|
state[1][3] ^= gf_mul[col[2]][1];
|
|
state[1][3] ^= col[3];
|
|
state[2][3] = col[0];
|
|
state[2][3] ^= col[1];
|
|
state[2][3] ^= gf_mul[col[2]][0];
|
|
state[2][3] ^= gf_mul[col[3]][1];
|
|
state[3][3] = gf_mul[col[0]][1];
|
|
state[3][3] ^= col[1];
|
|
state[3][3] ^= col[2];
|
|
state[3][3] ^= gf_mul[col[3]][0];
|
|
}
|
|
|
|
void InvMixColumns(BYTE state[][4])
|
|
{
|
|
BYTE col[4];
|
|
|
|
// Column 1
|
|
col[0] = state[0][0];
|
|
col[1] = state[1][0];
|
|
col[2] = state[2][0];
|
|
col[3] = state[3][0];
|
|
state[0][0] = gf_mul[col[0]][5];
|
|
state[0][0] ^= gf_mul[col[1]][3];
|
|
state[0][0] ^= gf_mul[col[2]][4];
|
|
state[0][0] ^= gf_mul[col[3]][2];
|
|
state[1][0] = gf_mul[col[0]][2];
|
|
state[1][0] ^= gf_mul[col[1]][5];
|
|
state[1][0] ^= gf_mul[col[2]][3];
|
|
state[1][0] ^= gf_mul[col[3]][4];
|
|
state[2][0] = gf_mul[col[0]][4];
|
|
state[2][0] ^= gf_mul[col[1]][2];
|
|
state[2][0] ^= gf_mul[col[2]][5];
|
|
state[2][0] ^= gf_mul[col[3]][3];
|
|
state[3][0] = gf_mul[col[0]][3];
|
|
state[3][0] ^= gf_mul[col[1]][4];
|
|
state[3][0] ^= gf_mul[col[2]][2];
|
|
state[3][0] ^= gf_mul[col[3]][5];
|
|
// Column 2
|
|
col[0] = state[0][1];
|
|
col[1] = state[1][1];
|
|
col[2] = state[2][1];
|
|
col[3] = state[3][1];
|
|
state[0][1] = gf_mul[col[0]][5];
|
|
state[0][1] ^= gf_mul[col[1]][3];
|
|
state[0][1] ^= gf_mul[col[2]][4];
|
|
state[0][1] ^= gf_mul[col[3]][2];
|
|
state[1][1] = gf_mul[col[0]][2];
|
|
state[1][1] ^= gf_mul[col[1]][5];
|
|
state[1][1] ^= gf_mul[col[2]][3];
|
|
state[1][1] ^= gf_mul[col[3]][4];
|
|
state[2][1] = gf_mul[col[0]][4];
|
|
state[2][1] ^= gf_mul[col[1]][2];
|
|
state[2][1] ^= gf_mul[col[2]][5];
|
|
state[2][1] ^= gf_mul[col[3]][3];
|
|
state[3][1] = gf_mul[col[0]][3];
|
|
state[3][1] ^= gf_mul[col[1]][4];
|
|
state[3][1] ^= gf_mul[col[2]][2];
|
|
state[3][1] ^= gf_mul[col[3]][5];
|
|
// Column 3
|
|
col[0] = state[0][2];
|
|
col[1] = state[1][2];
|
|
col[2] = state[2][2];
|
|
col[3] = state[3][2];
|
|
state[0][2] = gf_mul[col[0]][5];
|
|
state[0][2] ^= gf_mul[col[1]][3];
|
|
state[0][2] ^= gf_mul[col[2]][4];
|
|
state[0][2] ^= gf_mul[col[3]][2];
|
|
state[1][2] = gf_mul[col[0]][2];
|
|
state[1][2] ^= gf_mul[col[1]][5];
|
|
state[1][2] ^= gf_mul[col[2]][3];
|
|
state[1][2] ^= gf_mul[col[3]][4];
|
|
state[2][2] = gf_mul[col[0]][4];
|
|
state[2][2] ^= gf_mul[col[1]][2];
|
|
state[2][2] ^= gf_mul[col[2]][5];
|
|
state[2][2] ^= gf_mul[col[3]][3];
|
|
state[3][2] = gf_mul[col[0]][3];
|
|
state[3][2] ^= gf_mul[col[1]][4];
|
|
state[3][2] ^= gf_mul[col[2]][2];
|
|
state[3][2] ^= gf_mul[col[3]][5];
|
|
// Column 4
|
|
col[0] = state[0][3];
|
|
col[1] = state[1][3];
|
|
col[2] = state[2][3];
|
|
col[3] = state[3][3];
|
|
state[0][3] = gf_mul[col[0]][5];
|
|
state[0][3] ^= gf_mul[col[1]][3];
|
|
state[0][3] ^= gf_mul[col[2]][4];
|
|
state[0][3] ^= gf_mul[col[3]][2];
|
|
state[1][3] = gf_mul[col[0]][2];
|
|
state[1][3] ^= gf_mul[col[1]][5];
|
|
state[1][3] ^= gf_mul[col[2]][3];
|
|
state[1][3] ^= gf_mul[col[3]][4];
|
|
state[2][3] = gf_mul[col[0]][4];
|
|
state[2][3] ^= gf_mul[col[1]][2];
|
|
state[2][3] ^= gf_mul[col[2]][5];
|
|
state[2][3] ^= gf_mul[col[3]][3];
|
|
state[3][3] = gf_mul[col[0]][3];
|
|
state[3][3] ^= gf_mul[col[1]][4];
|
|
state[3][3] ^= gf_mul[col[2]][2];
|
|
state[3][3] ^= gf_mul[col[3]][5];
|
|
}
|
|
|
|
/////////////////
|
|
// (En/De)Crypt
|
|
/////////////////
|
|
|
|
void aes_encrypt(const BYTE in[], BYTE out[], const WORD key[], int keysize)
|
|
{
|
|
BYTE state[4][4];
|
|
|
|
// Copy input array (should be 16 bytes long) to a matrix (sequential bytes are ordered
|
|
// by row, not col) called "state" for processing.
|
|
// *** Implementation note: The official AES documentation references the state by
|
|
// column, then row. Accessing an element in C requires row then column. Thus, all state
|
|
// references in AES must have the column and row indexes reversed for C implementation.
|
|
state[0][0] = in[0];
|
|
state[1][0] = in[1];
|
|
state[2][0] = in[2];
|
|
state[3][0] = in[3];
|
|
state[0][1] = in[4];
|
|
state[1][1] = in[5];
|
|
state[2][1] = in[6];
|
|
state[3][1] = in[7];
|
|
state[0][2] = in[8];
|
|
state[1][2] = in[9];
|
|
state[2][2] = in[10];
|
|
state[3][2] = in[11];
|
|
state[0][3] = in[12];
|
|
state[1][3] = in[13];
|
|
state[2][3] = in[14];
|
|
state[3][3] = in[15];
|
|
|
|
// Perform the necessary number of rounds. The round key is added first.
|
|
// The last round does not perform the MixColumns step.
|
|
AddRoundKey(state,&key[0]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[4]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[8]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[12]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[16]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[20]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[24]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[28]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[32]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[36]);
|
|
if (keysize != 128) {
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[40]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[44]);
|
|
if (keysize != 192) {
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[48]);
|
|
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[52]);
|
|
SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[56]);
|
|
}
|
|
else {
|
|
SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[48]);
|
|
}
|
|
}
|
|
else {
|
|
SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[40]);
|
|
}
|
|
|
|
// Copy the state to the output array.
|
|
out[0] = state[0][0];
|
|
out[1] = state[1][0];
|
|
out[2] = state[2][0];
|
|
out[3] = state[3][0];
|
|
out[4] = state[0][1];
|
|
out[5] = state[1][1];
|
|
out[6] = state[2][1];
|
|
out[7] = state[3][1];
|
|
out[8] = state[0][2];
|
|
out[9] = state[1][2];
|
|
out[10] = state[2][2];
|
|
out[11] = state[3][2];
|
|
out[12] = state[0][3];
|
|
out[13] = state[1][3];
|
|
out[14] = state[2][3];
|
|
out[15] = state[3][3];
|
|
}
|
|
|
|
void aes_decrypt(const BYTE in[], BYTE out[], const WORD key[], int keysize)
|
|
{
|
|
BYTE state[4][4];
|
|
|
|
// Copy the input to the state.
|
|
state[0][0] = in[0];
|
|
state[1][0] = in[1];
|
|
state[2][0] = in[2];
|
|
state[3][0] = in[3];
|
|
state[0][1] = in[4];
|
|
state[1][1] = in[5];
|
|
state[2][1] = in[6];
|
|
state[3][1] = in[7];
|
|
state[0][2] = in[8];
|
|
state[1][2] = in[9];
|
|
state[2][2] = in[10];
|
|
state[3][2] = in[11];
|
|
state[0][3] = in[12];
|
|
state[1][3] = in[13];
|
|
state[2][3] = in[14];
|
|
state[3][3] = in[15];
|
|
|
|
// Perform the necessary number of rounds. The round key is added first.
|
|
// The last round does not perform the MixColumns step.
|
|
if (keysize > 128) {
|
|
if (keysize > 192) {
|
|
AddRoundKey(state,&key[56]);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[52]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[48]);InvMixColumns(state);
|
|
}
|
|
else {
|
|
AddRoundKey(state,&key[48]);
|
|
}
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[44]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[40]);InvMixColumns(state);
|
|
}
|
|
else {
|
|
AddRoundKey(state,&key[40]);
|
|
}
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[36]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[32]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[28]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[24]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[20]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[16]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[12]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[8]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[4]);InvMixColumns(state);
|
|
InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[0]);
|
|
|
|
// Copy the state to the output array.
|
|
out[0] = state[0][0];
|
|
out[1] = state[1][0];
|
|
out[2] = state[2][0];
|
|
out[3] = state[3][0];
|
|
out[4] = state[0][1];
|
|
out[5] = state[1][1];
|
|
out[6] = state[2][1];
|
|
out[7] = state[3][1];
|
|
out[8] = state[0][2];
|
|
out[9] = state[1][2];
|
|
out[10] = state[2][2];
|
|
out[11] = state[3][2];
|
|
out[12] = state[0][3];
|
|
out[13] = state[1][3];
|
|
out[14] = state[2][3];
|
|
out[15] = state[3][3];
|
|
}
|
|
|
|
/*******************
|
|
** AES DEBUGGING FUNCTIONS
|
|
*******************/
|
|
/*
|
|
// This prints the "state" grid as a linear hex string.
|
|
void print_state(BYTE state[][4])
|
|
{
|
|
int idx,idx2;
|
|
|
|
for (idx=0; idx < 4; idx++)
|
|
for (idx2=0; idx2 < 4; idx2++)
|
|
printf("%02x",state[idx2][idx]);
|
|
printf("\n");
|
|
}
|
|
|
|
// This prints the key (4 consecutive ints) used for a given round as a linear hex string.
|
|
void print_rnd_key(WORD key[])
|
|
{
|
|
int idx;
|
|
|
|
for (idx=0; idx < 4; idx++)
|
|
printf("%08x",key[idx]);
|
|
printf("\n");
|
|
}
|
|
*/
|