From 070db10cc14e5f5f83ae7df708bd49e36d7433ee Mon Sep 17 00:00:00 2001 From: Peter Schwabe Date: Tue, 9 Apr 2019 14:35:44 +0200 Subject: [PATCH] Added (constant-time) AES implementation, based on BearSSL --- common/aes.c | 656 +++++++++++++++++++++++++++++++++++++++++++++++++++ common/aes.h | 46 ++++ 2 files changed, 702 insertions(+) create mode 100644 common/aes.c create mode 100644 common/aes.h diff --git a/common/aes.c b/common/aes.c new file mode 100644 index 00000000..746514fe --- /dev/null +++ b/common/aes.c @@ -0,0 +1,656 @@ +/* + * AES implementation based on code from BearSSL (https://bearssl.org/) + * by Thomas Pornin. + * + * + * Copyright (c) 2016 Thomas Pornin + * + * 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 +#include + +#include "ctaes.h" + +static inline uint32_t br_dec32le(const unsigned char *src) +{ + return (uint32_t)src[0] + | ((uint32_t)src[1] << 8) + | ((uint32_t)src[2] << 16) + | ((uint32_t)src[3] << 24); +} + + +static void br_range_dec32le(uint32_t *v, size_t num, const unsigned char *src) +{ + while (num-- > 0) { + *v ++ = br_dec32le(src); + src += 4; + } +} + + +static inline uint32_t br_swap32(uint32_t x) +{ + x = ((x & (uint32_t)0x00FF00FF) << 8) + | ((x >> 8) & (uint32_t)0x00FF00FF); + return (x << 16) | (x >> 16); +} + + +static inline void br_enc32le(unsigned char *dst, uint32_t x) +{ + dst[0] = (unsigned char)x; + dst[1] = (unsigned char)(x >> 8); + dst[2] = (unsigned char)(x >> 16); + dst[3] = (unsigned char)(x >> 24); +} + + +void br_range_enc32le(unsigned char *dst, const uint32_t *v, size_t num) +{ + while (num-- > 0) { + br_enc32le(dst, *v ++); + dst += 4; + } +} + + +static void br_aes_ct64_bitslice_Sbox(uint64_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). + */ + + uint64_t x0, x1, x2, x3, x4, x5, x6, x7; + uint64_t y1, y2, y3, y4, y5, y6, y7, y8, y9; + uint64_t y10, y11, y12, y13, y14, y15, y16, y17, y18, y19; + uint64_t y20, y21; + uint64_t z0, z1, z2, z3, z4, z5, z6, z7, z8, z9; + uint64_t z10, z11, z12, z13, z14, z15, z16, z17; + uint64_t t0, t1, t2, t3, t4, t5, t6, t7, t8, t9; + uint64_t t10, t11, t12, t13, t14, t15, t16, t17, t18, t19; + uint64_t t20, t21, t22, t23, t24, t25, t26, t27, t28, t29; + uint64_t t30, t31, t32, t33, t34, t35, t36, t37, t38, t39; + uint64_t t40, t41, t42, t43, t44, t45, t46, t47, t48, t49; + uint64_t t50, t51, t52, t53, t54, t55, t56, t57, t58, t59; + uint64_t t60, t61, t62, t63, t64, t65, t66, t67; + uint64_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; +} + +static void br_aes_ct64_ortho(uint64_t *q) +{ +#define SWAPN(cl, ch, s, x, y) do { \ + uint64_t a, b; \ + a = (x); \ + b = (y); \ + (x) = (a & (uint64_t)cl) | ((b & (uint64_t)cl) << (s)); \ + (y) = ((a & (uint64_t)ch) >> (s)) | (b & (uint64_t)ch); \ + } while (0) + +#define SWAP2(x, y) SWAPN(0x5555555555555555, 0xAAAAAAAAAAAAAAAA, 1, x, y) +#define SWAP4(x, y) SWAPN(0x3333333333333333, 0xCCCCCCCCCCCCCCCC, 2, x, y) +#define SWAP8(x, y) SWAPN(0x0F0F0F0F0F0F0F0F, 0xF0F0F0F0F0F0F0F0, 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 void br_aes_ct64_interleave_in(uint64_t *q0, uint64_t *q1, const uint32_t *w) +{ + uint64_t x0, x1, x2, x3; + + x0 = w[0]; + x1 = w[1]; + x2 = w[2]; + x3 = w[3]; + x0 |= (x0 << 16); + x1 |= (x1 << 16); + x2 |= (x2 << 16); + x3 |= (x3 << 16); + x0 &= (uint64_t)0x0000FFFF0000FFFF; + x1 &= (uint64_t)0x0000FFFF0000FFFF; + x2 &= (uint64_t)0x0000FFFF0000FFFF; + x3 &= (uint64_t)0x0000FFFF0000FFFF; + x0 |= (x0 << 8); + x1 |= (x1 << 8); + x2 |= (x2 << 8); + x3 |= (x3 << 8); + x0 &= (uint64_t)0x00FF00FF00FF00FF; + x1 &= (uint64_t)0x00FF00FF00FF00FF; + x2 &= (uint64_t)0x00FF00FF00FF00FF; + x3 &= (uint64_t)0x00FF00FF00FF00FF; + *q0 = x0 | (x2 << 8); + *q1 = x1 | (x3 << 8); +} + + +static void br_aes_ct64_interleave_out(uint32_t *w, uint64_t q0, uint64_t q1) +{ + uint64_t x0, x1, x2, x3; + + x0 = q0 & (uint64_t)0x00FF00FF00FF00FF; + x1 = q1 & (uint64_t)0x00FF00FF00FF00FF; + x2 = (q0 >> 8) & (uint64_t)0x00FF00FF00FF00FF; + x3 = (q1 >> 8) & (uint64_t)0x00FF00FF00FF00FF; + x0 |= (x0 >> 8); + x1 |= (x1 >> 8); + x2 |= (x2 >> 8); + x3 |= (x3 >> 8); + x0 &= (uint64_t)0x0000FFFF0000FFFF; + x1 &= (uint64_t)0x0000FFFF0000FFFF; + x2 &= (uint64_t)0x0000FFFF0000FFFF; + x3 &= (uint64_t)0x0000FFFF0000FFFF; + w[0] = (uint32_t)x0 | (uint32_t)(x0 >> 16); + w[1] = (uint32_t)x1 | (uint32_t)(x1 >> 16); + w[2] = (uint32_t)x2 | (uint32_t)(x2 >> 16); + w[3] = (uint32_t)x3 | (uint32_t)(x3 >> 16); +} + +static const unsigned char Rcon[] = { + 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36 +}; + +static uint32_t sub_word(uint32_t x) +{ + uint64_t q[8]; + + memset(q, 0, sizeof q); + q[0] = x; + br_aes_ct64_ortho(q); + br_aes_ct64_bitslice_Sbox(q); + br_aes_ct64_ortho(q); + return (uint32_t)q[0]; +} + +static void br_aes_ct64_keysched(uint64_t *comp_skey, const unsigned char *key, int key_len) +{ + int i, j, k, nk, nkf; + uint32_t tmp; + uint32_t skey[60]; + unsigned nrounds = 10+((key_len-16)>>2); + + nk = (int)(key_len >> 2); + nkf = (int)((nrounds + 1) << 2); + br_range_dec32le(skey, (key_len >> 2), key); + tmp = skey[(key_len >> 2) - 1]; + 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]; + skey[i] = tmp; + if (++ j == nk) { + j = 0; + k ++; + } + } + + for (i = 0, j = 0; i < nkf; i += 4, j += 2) { + uint64_t q[8]; + + br_aes_ct64_interleave_in(&q[0], &q[4], skey + i); + q[1] = q[0]; + q[2] = q[0]; + q[3] = q[0]; + q[5] = q[4]; + q[6] = q[4]; + q[7] = q[4]; + br_aes_ct64_ortho(q); + comp_skey[j + 0] = + (q[0] & (uint64_t)0x1111111111111111) + | (q[1] & (uint64_t)0x2222222222222222) + | (q[2] & (uint64_t)0x4444444444444444) + | (q[3] & (uint64_t)0x8888888888888888); + comp_skey[j + 1] = + (q[4] & (uint64_t)0x1111111111111111) + | (q[5] & (uint64_t)0x2222222222222222) + | (q[6] & (uint64_t)0x4444444444444444) + | (q[7] & (uint64_t)0x8888888888888888); + } +} + +void br_aes_ct64_skey_expand(uint64_t *skey, const uint64_t *comp_skey, unsigned int nrounds) +{ + unsigned u, v, n; + + n = (nrounds + 1) << 1; + for (u = 0, v = 0; u < n; u ++, v += 4) { + uint64_t x0, x1, x2, x3; + + x0 = x1 = x2 = x3 = comp_skey[u]; + x0 &= (uint64_t)0x1111111111111111; + x1 &= (uint64_t)0x2222222222222222; + x2 &= (uint64_t)0x4444444444444444; + x3 &= (uint64_t)0x8888888888888888; + x1 >>= 1; + x2 >>= 2; + x3 >>= 3; + skey[v + 0] = (x0 << 4) - x0; + skey[v + 1] = (x1 << 4) - x1; + skey[v + 2] = (x2 << 4) - x2; + skey[v + 3] = (x3 << 4) - x3; + } +} + + +static inline void add_round_key(uint64_t *q, const uint64_t *sk) +{ + q[0] ^= sk[0]; + q[1] ^= sk[1]; + q[2] ^= sk[2]; + q[3] ^= sk[3]; + q[4] ^= sk[4]; + q[5] ^= sk[5]; + q[6] ^= sk[6]; + q[7] ^= sk[7]; +} + +static inline void shift_rows(uint64_t *q) +{ + int i; + + for (i = 0; i < 8; i ++) { + uint64_t x; + + x = q[i]; + q[i] = (x & (uint64_t)0x000000000000FFFF) + | ((x & (uint64_t)0x00000000FFF00000) >> 4) + | ((x & (uint64_t)0x00000000000F0000) << 12) + | ((x & (uint64_t)0x0000FF0000000000) >> 8) + | ((x & (uint64_t)0x000000FF00000000) << 8) + | ((x & (uint64_t)0xF000000000000000) >> 12) + | ((x & (uint64_t)0x0FFF000000000000) << 4); + } +} + +static inline uint64_t rotr32(uint64_t x) +{ + return (x << 32) | (x >> 32); +} + +static inline void mix_columns(uint64_t *q) +{ + uint64_t q0, q1, q2, q3, q4, q5, q6, q7; + uint64_t r0, r1, r2, r3, r4, r5, r6, r7; + + q0 = q[0]; + q1 = q[1]; + q2 = q[2]; + q3 = q[3]; + q4 = q[4]; + q5 = q[5]; + q6 = q[6]; + q7 = q[7]; + r0 = (q0 >> 16) | (q0 << 48); + r1 = (q1 >> 16) | (q1 << 48); + r2 = (q2 >> 16) | (q2 << 48); + r3 = (q3 >> 16) | (q3 << 48); + r4 = (q4 >> 16) | (q4 << 48); + r5 = (q5 >> 16) | (q5 << 48); + r6 = (q6 >> 16) | (q6 << 48); + r7 = (q7 >> 16) | (q7 << 48); + + q[0] = q7 ^ r7 ^ r0 ^ rotr32(q0 ^ r0); + q[1] = q0 ^ r0 ^ q7 ^ r7 ^ r1 ^ rotr32(q1 ^ r1); + q[2] = q1 ^ r1 ^ r2 ^ rotr32(q2 ^ r2); + q[3] = q2 ^ r2 ^ q7 ^ r7 ^ r3 ^ rotr32(q3 ^ r3); + q[4] = q3 ^ r3 ^ q7 ^ r7 ^ r4 ^ rotr32(q4 ^ r4); + q[5] = q4 ^ r4 ^ r5 ^ rotr32(q5 ^ r5); + q[6] = q5 ^ r5 ^ r6 ^ rotr32(q6 ^ r6); + q[7] = q6 ^ r6 ^ r7 ^ rotr32(q7 ^ r7); +} + + +static void inc4_be(uint32_t *x) +{ + uint32_t t = br_swap32(*x)+4; + *x = br_swap32(t); +} + + +static void aes_ecb4x(unsigned char out[64], const uint32_t ivw[16], const uint64_t *sk_exp, unsigned int nrounds) +{ + uint32_t w[16]; + uint64_t q[8]; + unsigned int i; + + memcpy(w, ivw, sizeof(w)); + for (i = 0; i < 4; i++) { + br_aes_ct64_interleave_in(&q[i], &q[i + 4], w + (i << 2)); + } + br_aes_ct64_ortho(q); + + + add_round_key(q, sk_exp); + for (i = 1; i < nrounds; i++) { + br_aes_ct64_bitslice_Sbox(q); + shift_rows(q); + mix_columns(q); + add_round_key(q, sk_exp + (i << 3)); + } + br_aes_ct64_bitslice_Sbox(q); + shift_rows(q); + add_round_key(q, sk_exp + 8*nrounds); + + br_aes_ct64_ortho(q); + for (i = 0; i < 4; i ++) { + br_aes_ct64_interleave_out(w + (i << 2), q[i], q[i + 4]); + } + br_range_enc32le(out, w, 16); +} + + +static void aes_ctr4x(unsigned char out[64], uint32_t ivw[16], const uint64_t *sk_exp, unsigned int nrounds) +{ + aes_ecb4x(out, ivw, sk_exp, nrounds); + + /* Increase counter for next 4 blocks */ + inc4_be(ivw+3); + inc4_be(ivw+7); + inc4_be(ivw+11); + inc4_be(ivw+15); +} + + +static void aes_ecb(unsigned char *out, unsigned char *in, size_t nblocks, const uint64_t *rkeys, unsigned int nrounds) +{ + uint32_t blocks[16]; + unsigned char t[64]; + + while(nblocks >= 4) + { + br_range_dec32le(blocks, 16, in); + aes_ecb4x(out, blocks, rkeys, nrounds); + nblocks -= 4; + in += 64; + out += 64; + } + + if(nblocks) + { + br_range_dec32le(blocks, nblocks*4, in); + aes_ecb4x(t, blocks, rkeys, nrounds); + memcpy(out, t, nblocks*16); + } +} + + +static void aes_ctr(unsigned char *out, size_t outlen, const unsigned char *iv, const uint64_t *rkeys, unsigned int nrounds) +{ + uint32_t ivw[16]; + size_t i; + uint32_t cc = 0; + + br_range_dec32le(ivw, 3, iv); + memcpy(ivw + 4, ivw, 3 * sizeof(uint32_t)); + memcpy(ivw + 8, ivw, 3 * sizeof(uint32_t)); + memcpy(ivw + 12, ivw, 3 * sizeof(uint32_t)); + ivw[ 3] = br_swap32(cc); + ivw[ 7] = br_swap32(cc + 1); + ivw[11] = br_swap32(cc + 2); + ivw[15] = br_swap32(cc + 3); + + while (outlen > 64) { + aes_ctr4x(out, ivw, rkeys, nrounds); + out += 64; + outlen -= 64; + } + if(outlen > 0) + { + unsigned char tmp[64]; + aes_ctr4x(tmp, ivw, rkeys, nrounds); + for(i=0;isk_exp, skey, 10); +} + + +void aes192_keyexp(aes192ctx *r, const unsigned char *key) +{ + uint64_t skey[26]; + + br_aes_ct64_keysched(skey, key, 24); + br_aes_ct64_skey_expand(r->sk_exp, skey, 12); +} + + +void aes256_keyexp(aes256ctx *r, const unsigned char *key) +{ + uint64_t skey[30]; + + br_aes_ct64_keysched(skey, key, 32); + br_aes_ct64_skey_expand(r->sk_exp, skey, 14); +} + + +void aes128_ecb(unsigned char *out, unsigned char *in, size_t nblocks, const aes128ctx *ctx) +{ + aes_ecb(out, in, nblocks, ctx->sk_exp, 10); +} + +void aes128_ctr(unsigned char *out, size_t outlen, const unsigned char *iv, const aes128ctx *ctx) +{ + aes_ctr(out, outlen, iv, ctx->sk_exp, 10); +} + +void aes192_ecb(unsigned char *out, unsigned char *in, size_t nblocks, const aes192ctx *ctx) +{ + aes_ecb(out, in, nblocks, ctx->sk_exp, 12); +} + +void aes192_ctr(unsigned char *out, size_t outlen, const unsigned char *iv, const aes192ctx *ctx) +{ + aes_ctr(out, outlen, iv, ctx->sk_exp, 12); +} + +void aes256_ecb(unsigned char *out, unsigned char *in, size_t nblocks, const aes256ctx *ctx) +{ + aes_ecb(out, in, nblocks, ctx->sk_exp, 14); +} + +void aes256_ctr(unsigned char *out, size_t outlen, const unsigned char *iv, const aes256ctx *ctx) +{ + aes_ctr(out, outlen, iv, ctx->sk_exp, 14); +} + diff --git a/common/aes.h b/common/aes.h new file mode 100644 index 00000000..247fe0e3 --- /dev/null +++ b/common/aes.h @@ -0,0 +1,46 @@ +#ifndef AES_H +#define AES_H + +#include + +#define AES128_KEYBYTES 16 +#define AES192_KEYBYTES 24 +#define AES256_KEYBYTES 32 +#define AESCTR_NONCEBYTES 12 + +typedef struct { + uint64_t sk_exp[88]; +} aes128ctx; + +typedef struct { + uint64_t sk_exp[104]; +} aes192ctx; + +typedef struct { + uint64_t sk_exp[120]; +} aes256ctx; + + + +void aes128_keyexp(aes128ctx *r, const unsigned char *key); + +void aes128_ctr(unsigned char *out, size_t outlen, const unsigned char *iv, const aes128ctx *ctx); + +void aes128_ecb(unsigned char *out, unsigned char *in, size_t nblocks, const aes128ctx *ctx); + + +void aes192_keyexp(aes192ctx *r, const unsigned char *key); + +void aes192_ctr(unsigned char *out, size_t outlen, const unsigned char *iv, const aes192ctx *ctx); + +void aes192_ecb(unsigned char *out, unsigned char *in, size_t nblocks, const aes192ctx *ctx); + + +void aes256_keyexp(aes256ctx *r, const unsigned char *key); + +void aes256_ctr(unsigned char *out, size_t outlen, const unsigned char *iv, const aes256ctx *ctx); + +void aes256_ecb(unsigned char *out, unsigned char *in, size_t nblocks, const aes256ctx *ctx); + + +#endif