X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fciphers%2Ftwofish%2Ftwofish.c;fp=libtomcrypt%2Fsrc%2Fciphers%2Ftwofish%2Ftwofish.c;h=b1584d1955a92798ad908a924a3a7ff9194904de;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage diff --git a/libtomcrypt/src/ciphers/twofish/twofish.c b/libtomcrypt/src/ciphers/twofish/twofish.c new file mode 100644 index 0000000..b1584d1 --- /dev/null +++ b/libtomcrypt/src/ciphers/twofish/twofish.c @@ -0,0 +1,711 @@ +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + */ + + /** + @file twofish.c + Implementation of Twofish by Tom St Denis + */ +#include "tomcrypt.h" + +#ifdef LTC_TWOFISH + +/* first LTC_TWOFISH_ALL_TABLES must ensure LTC_TWOFISH_TABLES is defined */ +#ifdef LTC_TWOFISH_ALL_TABLES +#ifndef LTC_TWOFISH_TABLES +#define LTC_TWOFISH_TABLES +#endif +#endif + +const struct ltc_cipher_descriptor twofish_desc = +{ + "twofish", + 7, + 16, 32, 16, 16, + &twofish_setup, + &twofish_ecb_encrypt, + &twofish_ecb_decrypt, + &twofish_test, + &twofish_done, + &twofish_keysize, + NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL +}; + +/* the two polynomials */ +#define MDS_POLY 0x169 +#define RS_POLY 0x14D + +/* The 4x8 RS Linear Transform */ +static const unsigned char RS[4][8] = { + { 0x01, 0xA4, 0x55, 0x87, 0x5A, 0x58, 0xDB, 0x9E }, + { 0xA4, 0x56, 0x82, 0xF3, 0X1E, 0XC6, 0X68, 0XE5 }, + { 0X02, 0XA1, 0XFC, 0XC1, 0X47, 0XAE, 0X3D, 0X19 }, + { 0XA4, 0X55, 0X87, 0X5A, 0X58, 0XDB, 0X9E, 0X03 } +}; + +#ifdef LTC_TWOFISH_SMALL +/* sbox usage orderings */ +static const unsigned char qord[4][5] = { + { 1, 1, 0, 0, 1 }, + { 0, 1, 1, 0, 0 }, + { 0, 0, 0, 1, 1 }, + { 1, 0, 1, 1, 0 } +}; +#endif /* LTC_TWOFISH_SMALL */ + +#ifdef LTC_TWOFISH_TABLES + +#define __LTC_TWOFISH_TAB_C__ +#include "twofish_tab.c" + +#define sbox(i, x) ((ulong32)SBOX[i][(x)&255]) + +#else + +/* The Q-box tables */ +static const unsigned char qbox[2][4][16] = { +{ + { 0x8, 0x1, 0x7, 0xD, 0x6, 0xF, 0x3, 0x2, 0x0, 0xB, 0x5, 0x9, 0xE, 0xC, 0xA, 0x4 }, + { 0xE, 0XC, 0XB, 0X8, 0X1, 0X2, 0X3, 0X5, 0XF, 0X4, 0XA, 0X6, 0X7, 0X0, 0X9, 0XD }, + { 0XB, 0XA, 0X5, 0XE, 0X6, 0XD, 0X9, 0X0, 0XC, 0X8, 0XF, 0X3, 0X2, 0X4, 0X7, 0X1 }, + { 0XD, 0X7, 0XF, 0X4, 0X1, 0X2, 0X6, 0XE, 0X9, 0XB, 0X3, 0X0, 0X8, 0X5, 0XC, 0XA } +}, +{ + { 0X2, 0X8, 0XB, 0XD, 0XF, 0X7, 0X6, 0XE, 0X3, 0X1, 0X9, 0X4, 0X0, 0XA, 0XC, 0X5 }, + { 0X1, 0XE, 0X2, 0XB, 0X4, 0XC, 0X3, 0X7, 0X6, 0XD, 0XA, 0X5, 0XF, 0X9, 0X0, 0X8 }, + { 0X4, 0XC, 0X7, 0X5, 0X1, 0X6, 0X9, 0XA, 0X0, 0XE, 0XD, 0X8, 0X2, 0XB, 0X3, 0XF }, + { 0xB, 0X9, 0X5, 0X1, 0XC, 0X3, 0XD, 0XE, 0X6, 0X4, 0X7, 0XF, 0X2, 0X0, 0X8, 0XA } +} +}; + +/* computes S_i[x] */ +#ifdef LTC_CLEAN_STACK +static ulong32 _sbox(int i, ulong32 x) +#else +static ulong32 sbox(int i, ulong32 x) +#endif +{ + unsigned char a0,b0,a1,b1,a2,b2,a3,b3,a4,b4,y; + + /* a0,b0 = [x/16], x mod 16 */ + a0 = (unsigned char)((x>>4)&15); + b0 = (unsigned char)((x)&15); + + /* a1 = a0 ^ b0 */ + a1 = a0 ^ b0; + + /* b1 = a0 ^ ROR(b0, 1) ^ 8a0 */ + b1 = (a0 ^ ((b0<<3)|(b0>>1)) ^ (a0<<3)) & 15; + + /* a2,b2 = t0[a1], t1[b1] */ + a2 = qbox[i][0][(int)a1]; + b2 = qbox[i][1][(int)b1]; + + /* a3 = a2 ^ b2 */ + a3 = a2 ^ b2; + + /* b3 = a2 ^ ROR(b2, 1) ^ 8a2 */ + b3 = (a2 ^ ((b2<<3)|(b2>>1)) ^ (a2<<3)) & 15; + + /* a4,b4 = t2[a3], t3[b3] */ + a4 = qbox[i][2][(int)a3]; + b4 = qbox[i][3][(int)b3]; + + /* y = 16b4 + a4 */ + y = (b4 << 4) + a4; + + /* return result */ + return (ulong32)y; +} + +#ifdef LTC_CLEAN_STACK +static ulong32 sbox(int i, ulong32 x) +{ + ulong32 y; + y = _sbox(i, x); + burn_stack(sizeof(unsigned char) * 11); + return y; +} +#endif /* LTC_CLEAN_STACK */ + +#endif /* LTC_TWOFISH_TABLES */ + +/* computes ab mod p */ +static ulong32 gf_mult(ulong32 a, ulong32 b, ulong32 p) +{ + ulong32 result, B[2], P[2]; + + P[1] = p; + B[1] = b; + result = P[0] = B[0] = 0; + + /* unrolled branchless GF multiplier */ + result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1); + result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1); + result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1); + result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1); + result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1); + result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1); + result ^= B[a&1]; a >>= 1; B[1] = P[B[1]>>7] ^ (B[1] << 1); + result ^= B[a&1]; + + return result; +} + +/* computes [y0 y1 y2 y3] = MDS . [x0] */ +#ifndef LTC_TWOFISH_TABLES +static ulong32 mds_column_mult(unsigned char in, int col) +{ + ulong32 x01, x5B, xEF; + + x01 = in; + x5B = gf_mult(in, 0x5B, MDS_POLY); + xEF = gf_mult(in, 0xEF, MDS_POLY); + + switch (col) { + case 0: + return (x01 << 0 ) | + (x5B << 8 ) | + (xEF << 16) | + (xEF << 24); + case 1: + return (xEF << 0 ) | + (xEF << 8 ) | + (x5B << 16) | + (x01 << 24); + case 2: + return (x5B << 0 ) | + (xEF << 8 ) | + (x01 << 16) | + (xEF << 24); + case 3: + return (x5B << 0 ) | + (x01 << 8 ) | + (xEF << 16) | + (x5B << 24); + } + /* avoid warnings, we'd never get here normally but just to calm compiler warnings... */ + return 0; +} + +#else /* !LTC_TWOFISH_TABLES */ + +#define mds_column_mult(x, i) mds_tab[i][x] + +#endif /* LTC_TWOFISH_TABLES */ + +/* Computes [y0 y1 y2 y3] = MDS . [x0 x1 x2 x3] */ +static void mds_mult(const unsigned char *in, unsigned char *out) +{ + int x; + ulong32 tmp; + for (tmp = x = 0; x < 4; x++) { + tmp ^= mds_column_mult(in[x], x); + } + STORE32L(tmp, out); +} + +#ifdef LTC_TWOFISH_ALL_TABLES +/* computes [y0 y1 y2 y3] = RS . [x0 x1 x2 x3 x4 x5 x6 x7] */ +static void rs_mult(const unsigned char *in, unsigned char *out) +{ + ulong32 tmp; + tmp = rs_tab0[in[0]] ^ rs_tab1[in[1]] ^ rs_tab2[in[2]] ^ rs_tab3[in[3]] ^ + rs_tab4[in[4]] ^ rs_tab5[in[5]] ^ rs_tab6[in[6]] ^ rs_tab7[in[7]]; + STORE32L(tmp, out); +} + +#else /* !LTC_TWOFISH_ALL_TABLES */ + +/* computes [y0 y1 y2 y3] = RS . [x0 x1 x2 x3 x4 x5 x6 x7] */ +static void rs_mult(const unsigned char *in, unsigned char *out) +{ + int x, y; + for (x = 0; x < 4; x++) { + out[x] = 0; + for (y = 0; y < 8; y++) { + out[x] ^= gf_mult(in[y], RS[x][y], RS_POLY); + } + } +} + +#endif + +/* computes h(x) */ +static void h_func(const unsigned char *in, unsigned char *out, unsigned char *M, int k, int offset) +{ + int x; + unsigned char y[4]; + for (x = 0; x < 4; x++) { + y[x] = in[x]; + } + switch (k) { + case 4: + y[0] = (unsigned char)(sbox(1, (ulong32)y[0]) ^ M[4 * (6 + offset) + 0]); + y[1] = (unsigned char)(sbox(0, (ulong32)y[1]) ^ M[4 * (6 + offset) + 1]); + y[2] = (unsigned char)(sbox(0, (ulong32)y[2]) ^ M[4 * (6 + offset) + 2]); + y[3] = (unsigned char)(sbox(1, (ulong32)y[3]) ^ M[4 * (6 + offset) + 3]); + /* FALLTHROUGH */ + case 3: + y[0] = (unsigned char)(sbox(1, (ulong32)y[0]) ^ M[4 * (4 + offset) + 0]); + y[1] = (unsigned char)(sbox(1, (ulong32)y[1]) ^ M[4 * (4 + offset) + 1]); + y[2] = (unsigned char)(sbox(0, (ulong32)y[2]) ^ M[4 * (4 + offset) + 2]); + y[3] = (unsigned char)(sbox(0, (ulong32)y[3]) ^ M[4 * (4 + offset) + 3]); + /* FALLTHROUGH */ + case 2: + y[0] = (unsigned char)(sbox(1, sbox(0, sbox(0, (ulong32)y[0]) ^ M[4 * (2 + offset) + 0]) ^ M[4 * (0 + offset) + 0])); + y[1] = (unsigned char)(sbox(0, sbox(0, sbox(1, (ulong32)y[1]) ^ M[4 * (2 + offset) + 1]) ^ M[4 * (0 + offset) + 1])); + y[2] = (unsigned char)(sbox(1, sbox(1, sbox(0, (ulong32)y[2]) ^ M[4 * (2 + offset) + 2]) ^ M[4 * (0 + offset) + 2])); + y[3] = (unsigned char)(sbox(0, sbox(1, sbox(1, (ulong32)y[3]) ^ M[4 * (2 + offset) + 3]) ^ M[4 * (0 + offset) + 3])); + /* FALLTHROUGH */ + } + mds_mult(y, out); +} + +#ifndef LTC_TWOFISH_SMALL + +/* for GCC we don't use pointer aliases */ +#if defined(__GNUC__) + #define S1 skey->twofish.S[0] + #define S2 skey->twofish.S[1] + #define S3 skey->twofish.S[2] + #define S4 skey->twofish.S[3] +#endif + +/* the G function */ +#define g_func(x, dum) (S1[byte(x,0)] ^ S2[byte(x,1)] ^ S3[byte(x,2)] ^ S4[byte(x,3)]) +#define g1_func(x, dum) (S2[byte(x,0)] ^ S3[byte(x,1)] ^ S4[byte(x,2)] ^ S1[byte(x,3)]) + +#else + +#ifdef LTC_CLEAN_STACK +static ulong32 _g_func(ulong32 x, symmetric_key *key) +#else +static ulong32 g_func(ulong32 x, symmetric_key *key) +#endif +{ + unsigned char g, i, y, z; + ulong32 res; + + res = 0; + for (y = 0; y < 4; y++) { + z = key->twofish.start; + + /* do unkeyed substitution */ + g = sbox(qord[y][z++], (x >> (8*y)) & 255); + + /* first subkey */ + i = 0; + + /* do key mixing+sbox until z==5 */ + while (z != 5) { + g = g ^ key->twofish.S[4*i++ + y]; + g = sbox(qord[y][z++], g); + } + + /* multiply g by a column of the MDS */ + res ^= mds_column_mult(g, y); + } + return res; +} + +#define g1_func(x, key) g_func(ROLc(x, 8), key) + +#ifdef LTC_CLEAN_STACK +static ulong32 g_func(ulong32 x, symmetric_key *key) +{ + ulong32 y; + y = _g_func(x, key); + burn_stack(sizeof(unsigned char) * 4 + sizeof(ulong32)); + return y; +} +#endif /* LTC_CLEAN_STACK */ + +#endif /* LTC_TWOFISH_SMALL */ + + /** + Initialize the Twofish block cipher + @param key The symmetric key you wish to pass + @param keylen The key length in bytes + @param num_rounds The number of rounds desired (0 for default) + @param skey The key in as scheduled by this function. + @return CRYPT_OK if successful + */ +#ifdef LTC_CLEAN_STACK +static int _twofish_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) +#else +int twofish_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey) +#endif +{ +#ifndef LTC_TWOFISH_SMALL + unsigned char S[4*4], tmpx0, tmpx1; +#endif + int k, x, y; + unsigned char tmp[4], tmp2[4], M[8*4]; + ulong32 A, B; + + LTC_ARGCHK(key != NULL); + LTC_ARGCHK(skey != NULL); + + /* invalid arguments? */ + if (num_rounds != 16 && num_rounds != 0) { + return CRYPT_INVALID_ROUNDS; + } + + if (keylen != 16 && keylen != 24 && keylen != 32) { + return CRYPT_INVALID_KEYSIZE; + } + + /* k = keysize/64 [but since our keysize is in bytes...] */ + k = keylen / 8; + + /* copy the key into M */ + for (x = 0; x < keylen; x++) { + M[x] = key[x] & 255; + } + + /* create the S[..] words */ +#ifndef LTC_TWOFISH_SMALL + for (x = 0; x < k; x++) { + rs_mult(M+(x*8), S+(x*4)); + } +#else + for (x = 0; x < k; x++) { + rs_mult(M+(x*8), skey->twofish.S+(x*4)); + } +#endif + + /* make subkeys */ + for (x = 0; x < 20; x++) { + /* A = h(p * 2x, Me) */ + for (y = 0; y < 4; y++) { + tmp[y] = x+x; + } + h_func(tmp, tmp2, M, k, 0); + LOAD32L(A, tmp2); + + /* B = ROL(h(p * (2x + 1), Mo), 8) */ + for (y = 0; y < 4; y++) { + tmp[y] = (unsigned char)(x+x+1); + } + h_func(tmp, tmp2, M, k, 1); + LOAD32L(B, tmp2); + B = ROLc(B, 8); + + /* K[2i] = A + B */ + skey->twofish.K[x+x] = (A + B) & 0xFFFFFFFFUL; + + /* K[2i+1] = (A + 2B) <<< 9 */ + skey->twofish.K[x+x+1] = ROLc(B + B + A, 9); + } + +#ifndef LTC_TWOFISH_SMALL + /* make the sboxes (large ram variant) */ + if (k == 2) { + 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, tmpx0 ^ S[0]) ^ S[4])),0); + skey->twofish.S[1][x] = mds_column_mult(sbox(0, (sbox(0, tmpx1 ^ S[1]) ^ S[5])),1); + skey->twofish.S[2][x] = mds_column_mult(sbox(1, (sbox(1, tmpx0 ^ S[2]) ^ S[6])),2); + skey->twofish.S[3][x] = mds_column_mult(sbox(0, (sbox(1, tmpx1 ^ S[3]) ^ S[7])),3); + } + } else if (k == 3) { + 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, 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: $Format:%ai$ */