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Diffstat (limited to 'third_party/bearssl/src/aes_ct.c')
| -rw-r--r-- | third_party/bearssl/src/aes_ct.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/third_party/bearssl/src/aes_ct.c b/third_party/bearssl/src/aes_ct.c new file mode 100644 index 0000000..66776d9 --- /dev/null +++ b/third_party/bearssl/src/aes_ct.c @@ -0,0 +1,328 @@ +/* + * Copyright (c) 2016 Thomas Pornin <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "inner.h" + +/* see inner.h */ +void +br_aes_ct_bitslice_Sbox(uint32_t *q) +{ + /* + * This S-box implementation is a straightforward translation of + * the circuit described by Boyar and Peralta in "A new + * combinational logic minimization technique with applications + * to cryptology" (https://eprint.iacr.org/2009/191.pdf). + * + * Note that variables x* (input) and s* (output) are numbered + * in "reverse" order (x0 is the high bit, x7 is the low bit). + */ + + uint32_t x0, x1, x2, x3, x4, x5, x6, x7; + uint32_t y1, y2, y3, y4, y5, y6, y7, y8, y9; + uint32_t y10, y11, y12, y13, y14, y15, y16, y17, y18, y19; + uint32_t y20, y21; + uint32_t z0, z1, z2, z3, z4, z5, z6, z7, z8, z9; + uint32_t z10, z11, z12, z13, z14, z15, z16, z17; + uint32_t t0, t1, t2, t3, t4, t5, t6, t7, t8, t9; + uint32_t t10, t11, t12, t13, t14, t15, t16, t17, t18, t19; + uint32_t t20, t21, t22, t23, t24, t25, t26, t27, t28, t29; + uint32_t t30, t31, t32, t33, t34, t35, t36, t37, t38, t39; + uint32_t t40, t41, t42, t43, t44, t45, t46, t47, t48, t49; + uint32_t t50, t51, t52, t53, t54, t55, t56, t57, t58, t59; + uint32_t t60, t61, t62, t63, t64, t65, t66, t67; + uint32_t s0, s1, s2, s3, s4, s5, s6, s7; + + x0 = q[7]; + x1 = q[6]; + x2 = q[5]; + x3 = q[4]; + x4 = q[3]; + x5 = q[2]; + x6 = q[1]; + x7 = q[0]; + + /* + * Top linear transformation. + */ + y14 = x3 ^ x5; + y13 = x0 ^ x6; + y9 = x0 ^ x3; + y8 = x0 ^ x5; + t0 = x1 ^ x2; + y1 = t0 ^ x7; + y4 = y1 ^ x3; + y12 = y13 ^ y14; + y2 = y1 ^ x0; + y5 = y1 ^ x6; + y3 = y5 ^ y8; + t1 = x4 ^ y12; + y15 = t1 ^ x5; + y20 = t1 ^ x1; + y6 = y15 ^ x7; + y10 = y15 ^ t0; + y11 = y20 ^ y9; + y7 = x7 ^ y11; + y17 = y10 ^ y11; + y19 = y10 ^ y8; + y16 = t0 ^ y11; + y21 = y13 ^ y16; + y18 = x0 ^ y16; + + /* + * Non-linear section. + */ + t2 = y12 & y15; + t3 = y3 & y6; + t4 = t3 ^ t2; + t5 = y4 & x7; + t6 = t5 ^ t2; + t7 = y13 & y16; + t8 = y5 & y1; + t9 = t8 ^ t7; + t10 = y2 & y7; + t11 = t10 ^ t7; + t12 = y9 & y11; + t13 = y14 & y17; + t14 = t13 ^ t12; + t15 = y8 & y10; + t16 = t15 ^ t12; + t17 = t4 ^ t14; + t18 = t6 ^ t16; + t19 = t9 ^ t14; + t20 = t11 ^ t16; + t21 = t17 ^ y20; + t22 = t18 ^ y19; + t23 = t19 ^ y21; + t24 = t20 ^ y18; + + t25 = t21 ^ t22; + t26 = t21 & t23; + t27 = t24 ^ t26; + t28 = t25 & t27; + t29 = t28 ^ t22; + t30 = t23 ^ t24; + t31 = t22 ^ t26; + t32 = t31 & t30; + t33 = t32 ^ t24; + t34 = t23 ^ t33; + t35 = t27 ^ t33; + t36 = t24 & t35; + t37 = t36 ^ t34; + t38 = t27 ^ t36; + t39 = t29 & t38; + t40 = t25 ^ t39; + + t41 = t40 ^ t37; + t42 = t29 ^ t33; + t43 = t29 ^ t40; + t44 = t33 ^ t37; + t45 = t42 ^ t41; + z0 = t44 & y15; + z1 = t37 & y6; + z2 = t33 & x7; + z3 = t43 & y16; + z4 = t40 & y1; + z5 = t29 & y7; + z6 = t42 & y11; + z7 = t45 & y17; + z8 = t41 & y10; + z9 = t44 & y12; + z10 = t37 & y3; + z11 = t33 & y4; + z12 = t43 & y13; + z13 = t40 & y5; + z14 = t29 & y2; + z15 = t42 & y9; + z16 = t45 & y14; + z17 = t41 & y8; + + /* + * Bottom linear transformation. + */ + t46 = z15 ^ z16; + t47 = z10 ^ z11; + t48 = z5 ^ z13; + t49 = z9 ^ z10; + t50 = z2 ^ z12; + t51 = z2 ^ z5; + t52 = z7 ^ z8; + t53 = z0 ^ z3; + t54 = z6 ^ z7; + t55 = z16 ^ z17; + t56 = z12 ^ t48; + t57 = t50 ^ t53; + t58 = z4 ^ t46; + t59 = z3 ^ t54; + t60 = t46 ^ t57; + t61 = z14 ^ t57; + t62 = t52 ^ t58; + t63 = t49 ^ t58; + t64 = z4 ^ t59; + t65 = t61 ^ t62; + t66 = z1 ^ t63; + s0 = t59 ^ t63; + s6 = t56 ^ ~t62; + s7 = t48 ^ ~t60; + t67 = t64 ^ t65; + s3 = t53 ^ t66; + s4 = t51 ^ t66; + s5 = t47 ^ t65; + s1 = t64 ^ ~s3; + s2 = t55 ^ ~t67; + + q[7] = s0; + q[6] = s1; + q[5] = s2; + q[4] = s3; + q[3] = s4; + q[2] = s5; + q[1] = s6; + q[0] = s7; +} + +/* see inner.h */ +void +br_aes_ct_ortho(uint32_t *q) +{ +#define SWAPN(cl, ch, s, x, y) do { \ + uint32_t a, b; \ + a = (x); \ + b = (y); \ + (x) = (a & (uint32_t)cl) | ((b & (uint32_t)cl) << (s)); \ + (y) = ((a & (uint32_t)ch) >> (s)) | (b & (uint32_t)ch); \ + } while (0) + +#define SWAP2(x, y) SWAPN(0x55555555, 0xAAAAAAAA, 1, x, y) +#define SWAP4(x, y) SWAPN(0x33333333, 0xCCCCCCCC, 2, x, y) +#define SWAP8(x, y) SWAPN(0x0F0F0F0F, 0xF0F0F0F0, 4, x, y) + + SWAP2(q[0], q[1]); + SWAP2(q[2], q[3]); + SWAP2(q[4], q[5]); + SWAP2(q[6], q[7]); + + SWAP4(q[0], q[2]); + SWAP4(q[1], q[3]); + SWAP4(q[4], q[6]); + SWAP4(q[5], q[7]); + + SWAP8(q[0], q[4]); + SWAP8(q[1], q[5]); + SWAP8(q[2], q[6]); + SWAP8(q[3], q[7]); +} + +static const unsigned char Rcon[] = { + 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36 +}; + +static uint32_t +sub_word(uint32_t x) +{ + uint32_t q[8]; + int i; + + for (i = 0; i < 8; i ++) { + q[i] = x; + } + br_aes_ct_ortho(q); + br_aes_ct_bitslice_Sbox(q); + br_aes_ct_ortho(q); + return q[0]; +} + +/* see inner.h */ +unsigned +br_aes_ct_keysched(uint32_t *comp_skey, const void *key, size_t key_len) +{ + unsigned num_rounds; + int i, j, k, nk, nkf; + uint32_t tmp; + uint32_t skey[120]; + + switch (key_len) { + case 16: + num_rounds = 10; + break; + case 24: + num_rounds = 12; + break; + case 32: + num_rounds = 14; + break; + default: + /* abort(); */ + return 0; + } + nk = (int)(key_len >> 2); + nkf = (int)((num_rounds + 1) << 2); + tmp = 0; + for (i = 0; i < nk; i ++) { + tmp = br_dec32le((const unsigned char *)key + (i << 2)); + skey[(i << 1) + 0] = tmp; + skey[(i << 1) + 1] = tmp; + } + for (i = nk, j = 0, k = 0; i < nkf; i ++) { + if (j == 0) { + tmp = (tmp << 24) | (tmp >> 8); + tmp = sub_word(tmp) ^ Rcon[k]; + } else if (nk > 6 && j == 4) { + tmp = sub_word(tmp); + } + tmp ^= skey[(i - nk) << 1]; + skey[(i << 1) + 0] = tmp; + skey[(i << 1) + 1] = tmp; + if (++ j == nk) { + j = 0; + k ++; + } + } + for (i = 0; i < nkf; i += 4) { + br_aes_ct_ortho(skey + (i << 1)); + } + for (i = 0, j = 0; i < nkf; i ++, j += 2) { + comp_skey[i] = (skey[j + 0] & 0x55555555) + | (skey[j + 1] & 0xAAAAAAAA); + } + return num_rounds; +} + +/* see inner.h */ +void +br_aes_ct_skey_expand(uint32_t *skey, + unsigned num_rounds, const uint32_t *comp_skey) +{ + unsigned u, v, n; + + n = (num_rounds + 1) << 2; + for (u = 0, v = 0; u < n; u ++, v += 2) { + uint32_t x, y; + + x = y = comp_skey[u]; + x &= 0x55555555; + skey[v + 0] = x | (x << 1); + y &= 0xAAAAAAAA; + skey[v + 1] = y | (y >> 1); + } +} |