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713 lines
20 KiB
713 lines
20 KiB
#define LTC_SOURCE
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis
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*
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* LibTomCrypt is a library that provides various cryptographic
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* algorithms in a highly modular and flexible manner.
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*
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* The library is free for all purposes without any express
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* guarantee it works.
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*/
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/**
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@file twofish.c
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Implementation of Twofish by Tom St Denis
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*/
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#include "tomcrypt.h"
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#ifdef LTC_TWOFISH
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/* first LTC_TWOFISH_ALL_TABLES must ensure LTC_TWOFISH_TABLES is defined */
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#ifdef LTC_TWOFISH_ALL_TABLES
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#ifndef LTC_TWOFISH_TABLES
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#define LTC_TWOFISH_TABLES
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#endif
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#endif
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const struct ltc_cipher_descriptor twofish_desc =
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{
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"twofish",
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7,
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16, 32, 16, 16,
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&twofish_setup,
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&twofish_ecb_encrypt,
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&twofish_ecb_decrypt,
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&twofish_test,
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&twofish_done,
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&twofish_keysize,
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NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
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};
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/* the two polynomials */
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#define MDS_POLY 0x169
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#define RS_POLY 0x14D
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/* The 4x8 RS Linear Transform */
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static const unsigned char RS[4][8] = {
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{ 0x01, 0xA4, 0x55, 0x87, 0x5A, 0x58, 0xDB, 0x9E },
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{ 0xA4, 0x56, 0x82, 0xF3, 0X1E, 0XC6, 0X68, 0XE5 },
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{ 0X02, 0XA1, 0XFC, 0XC1, 0X47, 0XAE, 0X3D, 0X19 },
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{ 0XA4, 0X55, 0X87, 0X5A, 0X58, 0XDB, 0X9E, 0X03 }
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};
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#ifdef LTC_TWOFISH_SMALL
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/* sbox usage orderings */
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static const unsigned char qord[4][5] = {
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{ 1, 1, 0, 0, 1 },
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{ 0, 1, 1, 0, 0 },
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{ 0, 0, 0, 1, 1 },
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{ 1, 0, 1, 1, 0 }
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};
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#endif /* LTC_TWOFISH_SMALL */
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#ifdef LTC_TWOFISH_TABLES
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#define __LTC_TWOFISH_TAB_C__
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#include "twofish_tab.c"
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#define sbox(i, x) ((ulong32)SBOX[i][(x)&255])
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#else
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/* The Q-box tables */
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static const unsigned char qbox[2][4][16] = {
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{
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{ 0x8, 0x1, 0x7, 0xD, 0x6, 0xF, 0x3, 0x2, 0x0, 0xB, 0x5, 0x9, 0xE, 0xC, 0xA, 0x4 },
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{ 0xE, 0XC, 0XB, 0X8, 0X1, 0X2, 0X3, 0X5, 0XF, 0X4, 0XA, 0X6, 0X7, 0X0, 0X9, 0XD },
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{ 0XB, 0XA, 0X5, 0XE, 0X6, 0XD, 0X9, 0X0, 0XC, 0X8, 0XF, 0X3, 0X2, 0X4, 0X7, 0X1 },
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{ 0XD, 0X7, 0XF, 0X4, 0X1, 0X2, 0X6, 0XE, 0X9, 0XB, 0X3, 0X0, 0X8, 0X5, 0XC, 0XA }
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},
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{
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{ 0X2, 0X8, 0XB, 0XD, 0XF, 0X7, 0X6, 0XE, 0X3, 0X1, 0X9, 0X4, 0X0, 0XA, 0XC, 0X5 },
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{ 0X1, 0XE, 0X2, 0XB, 0X4, 0XC, 0X3, 0X7, 0X6, 0XD, 0XA, 0X5, 0XF, 0X9, 0X0, 0X8 },
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{ 0X4, 0XC, 0X7, 0X5, 0X1, 0X6, 0X9, 0XA, 0X0, 0XE, 0XD, 0X8, 0X2, 0XB, 0X3, 0XF },
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{ 0xB, 0X9, 0X5, 0X1, 0XC, 0X3, 0XD, 0XE, 0X6, 0X4, 0X7, 0XF, 0X2, 0X0, 0X8, 0XA }
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}
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};
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/* computes S_i[x] */
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#ifdef LTC_CLEAN_STACK
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static ulong32 _sbox(int i, ulong32 x)
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#else
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static ulong32 sbox(int i, ulong32 x)
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#endif
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{
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unsigned char a0,b0,a1,b1,a2,b2,a3,b3,a4,b4,y;
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/* a0,b0 = [x/16], x mod 16 */
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a0 = (unsigned char)((x>>4)&15);
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b0 = (unsigned char)((x)&15);
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/* a1 = a0 ^ b0 */
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a1 = a0 ^ b0;
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/* b1 = a0 ^ ROR(b0, 1) ^ 8a0 */
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b1 = (a0 ^ ((b0<<3)|(b0>>1)) ^ (a0<<3)) & 15;
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/* a2,b2 = t0[a1], t1[b1] */
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a2 = qbox[i][0][(int)a1];
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b2 = qbox[i][1][(int)b1];
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/* a3 = a2 ^ b2 */
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a3 = a2 ^ b2;
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/* b3 = a2 ^ ROR(b2, 1) ^ 8a2 */
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b3 = (a2 ^ ((b2<<3)|(b2>>1)) ^ (a2<<3)) & 15;
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/* a4,b4 = t2[a3], t3[b3] */
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a4 = qbox[i][2][(int)a3];
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b4 = qbox[i][3][(int)b3];
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/* y = 16b4 + a4 */
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y = (b4 << 4) + a4;
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/* return result */
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return (ulong32)y;
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}
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#ifdef LTC_CLEAN_STACK
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static ulong32 sbox(int i, ulong32 x)
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{
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ulong32 y;
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y = _sbox(i, x);
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burn_stack(sizeof(unsigned char) * 11);
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return y;
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}
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#endif /* LTC_CLEAN_STACK */
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#endif /* LTC_TWOFISH_TABLES */
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/* computes ab mod p */
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static ulong32 gf_mult(ulong32 a, ulong32 b, ulong32 p)
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{
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ulong32 result, B[2], P[2];
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P[1] = p;
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B[1] = b;
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result = P[0] = B[0] = 0;
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/* unrolled branchless GF multiplier */
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result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1);
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result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1);
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result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1);
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result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1);
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result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1);
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result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1);
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result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1);
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result ^= B[a&1];
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return result;
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}
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/* computes [y0 y1 y2 y3] = MDS . [x0] */
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#ifndef LTC_TWOFISH_TABLES
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static ulong32 mds_column_mult(unsigned char in, int col)
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{
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ulong32 x01, x5B, xEF;
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x01 = in;
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x5B = gf_mult(in, 0x5B, MDS_POLY);
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xEF = gf_mult(in, 0xEF, MDS_POLY);
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switch (col) {
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case 0:
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return (x01 << 0 ) |
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(x5B << 8 ) |
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(xEF << 16) |
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(xEF << 24);
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case 1:
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return (xEF << 0 ) |
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(xEF << 8 ) |
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(x5B << 16) |
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(x01 << 24);
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case 2:
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return (x5B << 0 ) |
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(xEF << 8 ) |
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(x01 << 16) |
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(xEF << 24);
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case 3:
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return (x5B << 0 ) |
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(x01 << 8 ) |
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(xEF << 16) |
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(x5B << 24);
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}
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/* avoid warnings, we'd never get here normally but just to calm compiler warnings... */
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return 0;
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}
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#else /* !LTC_TWOFISH_TABLES */
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#define mds_column_mult(x, i) mds_tab[i][x]
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#endif /* LTC_TWOFISH_TABLES */
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/* Computes [y0 y1 y2 y3] = MDS . [x0 x1 x2 x3] */
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static void mds_mult(const unsigned char *in, unsigned char *out)
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{
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int x;
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ulong32 tmp;
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for (tmp = x = 0; x < 4; x++) {
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tmp ^= mds_column_mult(in[x], x);
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}
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STORE32L(tmp, out);
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}
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#ifdef LTC_TWOFISH_ALL_TABLES
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/* computes [y0 y1 y2 y3] = RS . [x0 x1 x2 x3 x4 x5 x6 x7] */
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static void rs_mult(const unsigned char *in, unsigned char *out)
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{
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ulong32 tmp;
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tmp = rs_tab0[in[0]] ^ rs_tab1[in[1]] ^ rs_tab2[in[2]] ^ rs_tab3[in[3]] ^
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rs_tab4[in[4]] ^ rs_tab5[in[5]] ^ rs_tab6[in[6]] ^ rs_tab7[in[7]];
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STORE32L(tmp, out);
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}
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#else /* !LTC_TWOFISH_ALL_TABLES */
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/* computes [y0 y1 y2 y3] = RS . [x0 x1 x2 x3 x4 x5 x6 x7] */
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static void rs_mult(const unsigned char *in, unsigned char *out)
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{
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int x, y;
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for (x = 0; x < 4; x++) {
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out[x] = 0;
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for (y = 0; y < 8; y++) {
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out[x] ^= gf_mult(in[y], RS[x][y], RS_POLY);
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}
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}
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}
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#endif
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/* computes h(x) */
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static void h_func(const unsigned char *in, unsigned char *out, unsigned char *M, int k, int offset)
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{
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int x;
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unsigned char y[4];
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for (x = 0; x < 4; x++) {
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y[x] = in[x];
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}
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switch (k) {
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case 4:
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y[0] = (unsigned char)(sbox(1, (ulong32)y[0]) ^ M[4 * (6 + offset) + 0]);
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y[1] = (unsigned char)(sbox(0, (ulong32)y[1]) ^ M[4 * (6 + offset) + 1]);
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y[2] = (unsigned char)(sbox(0, (ulong32)y[2]) ^ M[4 * (6 + offset) + 2]);
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y[3] = (unsigned char)(sbox(1, (ulong32)y[3]) ^ M[4 * (6 + offset) + 3]);
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/* FALLTHROUGH */
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case 3:
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y[0] = (unsigned char)(sbox(1, (ulong32)y[0]) ^ M[4 * (4 + offset) + 0]);
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y[1] = (unsigned char)(sbox(1, (ulong32)y[1]) ^ M[4 * (4 + offset) + 1]);
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y[2] = (unsigned char)(sbox(0, (ulong32)y[2]) ^ M[4 * (4 + offset) + 2]);
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y[3] = (unsigned char)(sbox(0, (ulong32)y[3]) ^ M[4 * (4 + offset) + 3]);
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/* FALLTHROUGH */
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case 2:
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y[0] = (unsigned char)(sbox(1, sbox(0, sbox(0, (ulong32)y[0]) ^ M[4 * (2 + offset) + 0]) ^ M[4 * (0 + offset) + 0]));
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y[1] = (unsigned char)(sbox(0, sbox(0, sbox(1, (ulong32)y[1]) ^ M[4 * (2 + offset) + 1]) ^ M[4 * (0 + offset) + 1]));
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y[2] = (unsigned char)(sbox(1, sbox(1, sbox(0, (ulong32)y[2]) ^ M[4 * (2 + offset) + 2]) ^ M[4 * (0 + offset) + 2]));
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y[3] = (unsigned char)(sbox(0, sbox(1, sbox(1, (ulong32)y[3]) ^ M[4 * (2 + offset) + 3]) ^ M[4 * (0 + offset) + 3]));
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/* FALLTHROUGH */
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}
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mds_mult(y, out);
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}
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#ifndef LTC_TWOFISH_SMALL
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/* for GCC we don't use pointer aliases */
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#if defined(__GNUC__)
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#define S1 skey->twofish.S[0]
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#define S2 skey->twofish.S[1]
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#define S3 skey->twofish.S[2]
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#define S4 skey->twofish.S[3]
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#endif
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/* the G function */
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#define g_func(x, dum) (S1[byte(x,0)] ^ S2[byte(x,1)] ^ S3[byte(x,2)] ^ S4[byte(x,3)])
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#define g1_func(x, dum) (S2[byte(x,0)] ^ S3[byte(x,1)] ^ S4[byte(x,2)] ^ S1[byte(x,3)])
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#else
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#ifdef LTC_CLEAN_STACK
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static ulong32 _g_func(ulong32 x, symmetric_key *key)
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#else
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static ulong32 g_func(ulong32 x, symmetric_key *key)
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#endif
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{
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unsigned char g, i, y, z;
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ulong32 res;
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res = 0;
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for (y = 0; y < 4; y++) {
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z = key->twofish.start;
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/* do unkeyed substitution */
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g = sbox(qord[y][z++], (x >> (8*y)) & 255);
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/* first subkey */
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i = 0;
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/* do key mixing+sbox until z==5 */
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while (z != 5) {
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g = g ^ key->twofish.S[4*i++ + y];
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g = sbox(qord[y][z++], g);
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}
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/* multiply g by a column of the MDS */
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res ^= mds_column_mult(g, y);
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}
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return res;
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}
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#define g1_func(x, key) g_func(ROLc(x, 8), key)
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#ifdef LTC_CLEAN_STACK
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static ulong32 g_func(ulong32 x, symmetric_key *key)
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{
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ulong32 y;
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y = _g_func(x, key);
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burn_stack(sizeof(unsigned char) * 4 + sizeof(ulong32));
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return y;
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}
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#endif /* LTC_CLEAN_STACK */
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#endif /* LTC_TWOFISH_SMALL */
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/**
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Initialize the Twofish block cipher
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@param key The symmetric key you wish to pass
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@param keylen The key length in bytes
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@param num_rounds The number of rounds desired (0 for default)
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@param skey The key in as scheduled by this function.
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@return CRYPT_OK if successful
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*/
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#ifdef LTC_CLEAN_STACK
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static int _twofish_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
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#else
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int twofish_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
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#endif
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{
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#ifndef LTC_TWOFISH_SMALL
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unsigned char S[4*4], tmpx0, tmpx1;
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#endif
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int k, x, y;
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unsigned char tmp[4], tmp2[4], M[8*4];
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ulong32 A, B;
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LTC_ARGCHK(key != NULL);
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LTC_ARGCHK(skey != NULL);
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/* invalid arguments? */
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if (num_rounds != 16 && num_rounds != 0) {
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return CRYPT_INVALID_ROUNDS;
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}
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if (keylen != 16 && keylen != 24 && keylen != 32) {
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return CRYPT_INVALID_KEYSIZE;
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}
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/* k = keysize/64 [but since our keysize is in bytes...] */
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k = keylen / 8;
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/* copy the key into M */
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for (x = 0; x < keylen; x++) {
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M[x] = key[x] & 255;
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}
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/* create the S[..] words */
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#ifndef LTC_TWOFISH_SMALL
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for (x = 0; x < k; x++) {
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rs_mult(M+(x*8), S+(x*4));
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}
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#else
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for (x = 0; x < k; x++) {
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rs_mult(M+(x*8), skey->twofish.S+(x*4));
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}
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#endif
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/* make subkeys */
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for (x = 0; x < 20; x++) {
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/* A = h(p * 2x, Me) */
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for (y = 0; y < 4; y++) {
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tmp[y] = x+x;
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}
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h_func(tmp, tmp2, M, k, 0);
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LOAD32L(A, tmp2);
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/* B = ROL(h(p * (2x + 1), Mo), 8) */
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for (y = 0; y < 4; y++) {
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tmp[y] = (unsigned char)(x+x+1);
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}
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h_func(tmp, tmp2, M, k, 1);
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LOAD32L(B, tmp2);
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B = ROLc(B, 8);
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/* K[2i] = A + B */
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skey->twofish.K[x+x] = (A + B) & 0xFFFFFFFFUL;
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/* K[2i+1] = (A + 2B) <<< 9 */
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skey->twofish.K[x+x+1] = ROLc(B + B + A, 9);
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}
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#ifndef LTC_TWOFISH_SMALL
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/* make the sboxes (large ram variant) */
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if (k == 2) {
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for (x = 0; x < 256; x++) {
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tmpx0 = (unsigned char)sbox(0, x);
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tmpx1 = (unsigned char)sbox(1, x);
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skey->twofish.S[0][x] = mds_column_mult(sbox(1, (sbox(0, tmpx0 ^ S[0]) ^ S[4])),0);
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skey->twofish.S[1][x] = mds_column_mult(sbox(0, (sbox(0, tmpx1 ^ S[1]) ^ S[5])),1);
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skey->twofish.S[2][x] = mds_column_mult(sbox(1, (sbox(1, tmpx0 ^ S[2]) ^ S[6])),2);
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skey->twofish.S[3][x] = mds_column_mult(sbox(0, (sbox(1, tmpx1 ^ S[3]) ^ S[7])),3);
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}
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} else if (k == 3) {
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for (x = 0; x < 256; x++) {
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tmpx0 = (unsigned char)sbox(0, x);
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tmpx1 = (unsigned char)sbox(1, x);
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skey->twofish.S[0][x] = mds_column_mult(sbox(1, (sbox(0, sbox(0, tmpx1 ^ S[0]) ^ S[4]) ^ S[8])),0);
|
|
skey->twofish.S[1][x] = mds_column_mult(sbox(0, (sbox(0, sbox(1, tmpx1 ^ S[1]) ^ S[5]) ^ S[9])),1);
|
|
skey->twofish.S[2][x] = mds_column_mult(sbox(1, (sbox(1, sbox(0, tmpx0 ^ S[2]) ^ S[6]) ^ S[10])),2);
|
|
skey->twofish.S[3][x] = mds_column_mult(sbox(0, (sbox(1, sbox(1, tmpx0 ^ S[3]) ^ S[7]) ^ S[11])),3);
|
|
}
|
|
} else {
|
|
for (x = 0; x < 256; x++) {
|
|
tmpx0 = (unsigned char)sbox(0, x);
|
|
tmpx1 = (unsigned char)sbox(1, x);
|
|
skey->twofish.S[0][x] = mds_column_mult(sbox(1, (sbox(0, sbox(0, sbox(1, tmpx1 ^ S[0]) ^ S[4]) ^ S[8]) ^ S[12])),0);
|
|
skey->twofish.S[1][x] = mds_column_mult(sbox(0, (sbox(0, sbox(1, sbox(1, tmpx0 ^ S[1]) ^ S[5]) ^ S[9]) ^ S[13])),1);
|
|
skey->twofish.S[2][x] = mds_column_mult(sbox(1, (sbox(1, sbox(0, sbox(0, tmpx0 ^ S[2]) ^ S[6]) ^ S[10]) ^ S[14])),2);
|
|
skey->twofish.S[3][x] = mds_column_mult(sbox(0, (sbox(1, sbox(1, sbox(0, tmpx1 ^ S[3]) ^ S[7]) ^ S[11]) ^ S[15])),3);
|
|
}
|
|
}
|
|
#else
|
|
/* where to start in the sbox layers */
|
|
/* small ram variant */
|
|
switch (k) {
|
|
case 4 : skey->twofish.start = 0; break;
|
|
case 3 : skey->twofish.start = 1; break;
|
|
default: skey->twofish.start = 2; break;
|
|
}
|
|
#endif
|
|
return CRYPT_OK;
|
|
}
|
|
|
|
#ifdef LTC_CLEAN_STACK
|
|
int twofish_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
|
|
{
|
|
int x;
|
|
x = _twofish_setup(key, keylen, num_rounds, skey);
|
|
burn_stack(sizeof(int) * 7 + sizeof(unsigned char) * 56 + sizeof(ulong32) * 2);
|
|
return x;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
Encrypts a block of text with Twofish
|
|
@param pt The input plaintext (16 bytes)
|
|
@param ct The output ciphertext (16 bytes)
|
|
@param skey The key as scheduled
|
|
@return CRYPT_OK if successful
|
|
*/
|
|
#ifdef LTC_CLEAN_STACK
|
|
static int _twofish_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
|
|
#else
|
|
int twofish_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
|
|
#endif
|
|
{
|
|
ulong32 a,b,c,d,ta,tb,tc,td,t1,t2, *k;
|
|
int r;
|
|
#if !defined(LTC_TWOFISH_SMALL) && !defined(__GNUC__)
|
|
ulong32 *S1, *S2, *S3, *S4;
|
|
#endif
|
|
|
|
LTC_ARGCHK(pt != NULL);
|
|
LTC_ARGCHK(ct != NULL);
|
|
LTC_ARGCHK(skey != NULL);
|
|
|
|
#if !defined(LTC_TWOFISH_SMALL) && !defined(__GNUC__)
|
|
S1 = skey->twofish.S[0];
|
|
S2 = skey->twofish.S[1];
|
|
S3 = skey->twofish.S[2];
|
|
S4 = skey->twofish.S[3];
|
|
#endif
|
|
|
|
LOAD32L(a,&pt[0]); LOAD32L(b,&pt[4]);
|
|
LOAD32L(c,&pt[8]); LOAD32L(d,&pt[12]);
|
|
a ^= skey->twofish.K[0];
|
|
b ^= skey->twofish.K[1];
|
|
c ^= skey->twofish.K[2];
|
|
d ^= skey->twofish.K[3];
|
|
|
|
k = skey->twofish.K + 8;
|
|
for (r = 8; r != 0; --r) {
|
|
t2 = g1_func(b, skey);
|
|
t1 = g_func(a, skey) + t2;
|
|
c = RORc(c ^ (t1 + k[0]), 1);
|
|
d = ROLc(d, 1) ^ (t2 + t1 + k[1]);
|
|
|
|
t2 = g1_func(d, skey);
|
|
t1 = g_func(c, skey) + t2;
|
|
a = RORc(a ^ (t1 + k[2]), 1);
|
|
b = ROLc(b, 1) ^ (t2 + t1 + k[3]);
|
|
k += 4;
|
|
}
|
|
|
|
/* output with "undo last swap" */
|
|
ta = c ^ skey->twofish.K[4];
|
|
tb = d ^ skey->twofish.K[5];
|
|
tc = a ^ skey->twofish.K[6];
|
|
td = b ^ skey->twofish.K[7];
|
|
|
|
/* store output */
|
|
STORE32L(ta,&ct[0]); STORE32L(tb,&ct[4]);
|
|
STORE32L(tc,&ct[8]); STORE32L(td,&ct[12]);
|
|
|
|
return CRYPT_OK;
|
|
}
|
|
|
|
#ifdef LTC_CLEAN_STACK
|
|
int twofish_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *skey)
|
|
{
|
|
int err = _twofish_ecb_encrypt(pt, ct, skey);
|
|
burn_stack(sizeof(ulong32) * 10 + sizeof(int));
|
|
return err;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
Decrypts a block of text with Twofish
|
|
@param ct The input ciphertext (16 bytes)
|
|
@param pt The output plaintext (16 bytes)
|
|
@param skey The key as scheduled
|
|
@return CRYPT_OK if successful
|
|
*/
|
|
#ifdef LTC_CLEAN_STACK
|
|
static int _twofish_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
|
|
#else
|
|
int twofish_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
|
|
#endif
|
|
{
|
|
ulong32 a,b,c,d,ta,tb,tc,td,t1,t2, *k;
|
|
int r;
|
|
#if !defined(LTC_TWOFISH_SMALL) && !defined(__GNUC__)
|
|
ulong32 *S1, *S2, *S3, *S4;
|
|
#endif
|
|
|
|
LTC_ARGCHK(pt != NULL);
|
|
LTC_ARGCHK(ct != NULL);
|
|
LTC_ARGCHK(skey != NULL);
|
|
|
|
#if !defined(LTC_TWOFISH_SMALL) && !defined(__GNUC__)
|
|
S1 = skey->twofish.S[0];
|
|
S2 = skey->twofish.S[1];
|
|
S3 = skey->twofish.S[2];
|
|
S4 = skey->twofish.S[3];
|
|
#endif
|
|
|
|
/* load input */
|
|
LOAD32L(ta,&ct[0]); LOAD32L(tb,&ct[4]);
|
|
LOAD32L(tc,&ct[8]); LOAD32L(td,&ct[12]);
|
|
|
|
/* undo undo final swap */
|
|
a = tc ^ skey->twofish.K[6];
|
|
b = td ^ skey->twofish.K[7];
|
|
c = ta ^ skey->twofish.K[4];
|
|
d = tb ^ skey->twofish.K[5];
|
|
|
|
k = skey->twofish.K + 36;
|
|
for (r = 8; r != 0; --r) {
|
|
t2 = g1_func(d, skey);
|
|
t1 = g_func(c, skey) + t2;
|
|
a = ROLc(a, 1) ^ (t1 + k[2]);
|
|
b = RORc(b ^ (t2 + t1 + k[3]), 1);
|
|
|
|
t2 = g1_func(b, skey);
|
|
t1 = g_func(a, skey) + t2;
|
|
c = ROLc(c, 1) ^ (t1 + k[0]);
|
|
d = RORc(d ^ (t2 + t1 + k[1]), 1);
|
|
k -= 4;
|
|
}
|
|
|
|
/* pre-white */
|
|
a ^= skey->twofish.K[0];
|
|
b ^= skey->twofish.K[1];
|
|
c ^= skey->twofish.K[2];
|
|
d ^= skey->twofish.K[3];
|
|
|
|
/* store */
|
|
STORE32L(a, &pt[0]); STORE32L(b, &pt[4]);
|
|
STORE32L(c, &pt[8]); STORE32L(d, &pt[12]);
|
|
return CRYPT_OK;
|
|
}
|
|
|
|
#ifdef LTC_CLEAN_STACK
|
|
int twofish_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *skey)
|
|
{
|
|
int err =_twofish_ecb_decrypt(ct, pt, skey);
|
|
burn_stack(sizeof(ulong32) * 10 + sizeof(int));
|
|
return err;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
Performs a self-test of the Twofish block cipher
|
|
@return CRYPT_OK if functional, CRYPT_NOP if self-test has been disabled
|
|
*/
|
|
int twofish_test(void)
|
|
{
|
|
#ifndef LTC_TEST
|
|
return CRYPT_NOP;
|
|
#else
|
|
static const struct {
|
|
int keylen;
|
|
unsigned char key[32], pt[16], ct[16];
|
|
} tests[] = {
|
|
{ 16,
|
|
{ 0x9F, 0x58, 0x9F, 0x5C, 0xF6, 0x12, 0x2C, 0x32,
|
|
0xB6, 0xBF, 0xEC, 0x2F, 0x2A, 0xE8, 0xC3, 0x5A },
|
|
{ 0xD4, 0x91, 0xDB, 0x16, 0xE7, 0xB1, 0xC3, 0x9E,
|
|
0x86, 0xCB, 0x08, 0x6B, 0x78, 0x9F, 0x54, 0x19 },
|
|
{ 0x01, 0x9F, 0x98, 0x09, 0xDE, 0x17, 0x11, 0x85,
|
|
0x8F, 0xAA, 0xC3, 0xA3, 0xBA, 0x20, 0xFB, 0xC3 }
|
|
}, {
|
|
24,
|
|
{ 0x88, 0xB2, 0xB2, 0x70, 0x6B, 0x10, 0x5E, 0x36,
|
|
0xB4, 0x46, 0xBB, 0x6D, 0x73, 0x1A, 0x1E, 0x88,
|
|
0xEF, 0xA7, 0x1F, 0x78, 0x89, 0x65, 0xBD, 0x44 },
|
|
{ 0x39, 0xDA, 0x69, 0xD6, 0xBA, 0x49, 0x97, 0xD5,
|
|
0x85, 0xB6, 0xDC, 0x07, 0x3C, 0xA3, 0x41, 0xB2 },
|
|
{ 0x18, 0x2B, 0x02, 0xD8, 0x14, 0x97, 0xEA, 0x45,
|
|
0xF9, 0xDA, 0xAC, 0xDC, 0x29, 0x19, 0x3A, 0x65 }
|
|
}, {
|
|
32,
|
|
{ 0xD4, 0x3B, 0xB7, 0x55, 0x6E, 0xA3, 0x2E, 0x46,
|
|
0xF2, 0xA2, 0x82, 0xB7, 0xD4, 0x5B, 0x4E, 0x0D,
|
|
0x57, 0xFF, 0x73, 0x9D, 0x4D, 0xC9, 0x2C, 0x1B,
|
|
0xD7, 0xFC, 0x01, 0x70, 0x0C, 0xC8, 0x21, 0x6F },
|
|
{ 0x90, 0xAF, 0xE9, 0x1B, 0xB2, 0x88, 0x54, 0x4F,
|
|
0x2C, 0x32, 0xDC, 0x23, 0x9B, 0x26, 0x35, 0xE6 },
|
|
{ 0x6C, 0xB4, 0x56, 0x1C, 0x40, 0xBF, 0x0A, 0x97,
|
|
0x05, 0x93, 0x1C, 0xB6, 0xD4, 0x08, 0xE7, 0xFA }
|
|
}
|
|
};
|
|
|
|
|
|
symmetric_key key;
|
|
unsigned char tmp[2][16];
|
|
int err, i, y;
|
|
|
|
for (i = 0; i < (int)(sizeof(tests)/sizeof(tests[0])); i++) {
|
|
if ((err = twofish_setup(tests[i].key, tests[i].keylen, 0, &key)) != CRYPT_OK) {
|
|
return err;
|
|
}
|
|
twofish_ecb_encrypt(tests[i].pt, tmp[0], &key);
|
|
twofish_ecb_decrypt(tmp[0], tmp[1], &key);
|
|
if (compare_testvector(tmp[0], 16, tests[i].ct, 16, "Twofish Encrypt", i) != 0 ||
|
|
compare_testvector(tmp[1], 16, tests[i].pt, 16, "Twofish Decrypt", i) != 0) {
|
|
return CRYPT_FAIL_TESTVECTOR;
|
|
}
|
|
/* now see if we can encrypt all zero bytes 1000 times, decrypt and come back where we started */
|
|
for (y = 0; y < 16; y++) tmp[0][y] = 0;
|
|
for (y = 0; y < 1000; y++) twofish_ecb_encrypt(tmp[0], tmp[0], &key);
|
|
for (y = 0; y < 1000; y++) twofish_ecb_decrypt(tmp[0], tmp[0], &key);
|
|
for (y = 0; y < 16; y++) if (tmp[0][y] != 0) return CRYPT_FAIL_TESTVECTOR;
|
|
}
|
|
return CRYPT_OK;
|
|
#endif
|
|
}
|
|
|
|
/** Terminate the context
|
|
@param skey The scheduled key
|
|
*/
|
|
void twofish_done(symmetric_key *skey)
|
|
{
|
|
LTC_UNUSED_PARAM(skey);
|
|
}
|
|
|
|
/**
|
|
Gets suitable key size
|
|
@param keysize [in/out] The length of the recommended key (in bytes). This function will store the suitable size back in this variable.
|
|
@return CRYPT_OK if the input key size is acceptable.
|
|
*/
|
|
int twofish_keysize(int *keysize)
|
|
{
|
|
LTC_ARGCHK(keysize);
|
|
if (*keysize < 16)
|
|
return CRYPT_INVALID_KEYSIZE;
|
|
if (*keysize < 24) {
|
|
*keysize = 16;
|
|
return CRYPT_OK;
|
|
} else if (*keysize < 32) {
|
|
*keysize = 24;
|
|
return CRYPT_OK;
|
|
} else {
|
|
*keysize = 32;
|
|
return CRYPT_OK;
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
/* ref: $Format:%D$ */
|
|
/* git commit: $Format:%H$ */
|
|
/* commit time: $Format:%ai$ */
|