--- /dev/null
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Modified for OpenBSD by Thomas Pornin and Mike Belopuhov.
+ *
+ * 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 <sys/types.h>
+#include <sys/systm.h>
+#include <sys/stdint.h>
+
+#include "aes.h"
+
+static inline void
+enc32le(void *dst, uint32_t x)
+{
+ unsigned char *buf = dst;
+
+ buf[0] = (unsigned char)x;
+ buf[1] = (unsigned char)(x >> 8);
+ buf[2] = (unsigned char)(x >> 16);
+ buf[3] = (unsigned char)(x >> 24);
+}
+
+static inline uint32_t
+dec32le(const void *src)
+{
+ const unsigned char *buf = src;
+
+ return (uint32_t)buf[0]
+ | ((uint32_t)buf[1] << 8)
+ | ((uint32_t)buf[2] << 16)
+ | ((uint32_t)buf[3] << 24);
+}
+
+/*
+ * This constant-time implementation is "bitsliced": the 128-bit state is
+ * split over eight 32-bit words q* in the following way:
+ *
+ * -- Input block consists in 16 bytes:
+ * a00 a10 a20 a30 a01 a11 a21 a31 a02 a12 a22 a32 a03 a13 a23 a33
+ * In the terminology of FIPS 197, this is a 4x4 matrix which is read
+ * column by column.
+ *
+ * -- Each byte is split into eight bits which are distributed over the
+ * eight words, at the same rank. Thus, for a byte x at rank k, bit 0
+ * (least significant) of x will be at rank k in q0 (if that bit is b,
+ * then it contributes "b << k" to the value of q0), bit 1 of x will be
+ * at rank k in q1, and so on.
+ *
+ * -- Ranks given to bits are in "row order" and are either all even, or
+ * all odd. Two independent AES states are thus interleaved, one using
+ * the even ranks, the other the odd ranks. Row order means:
+ * a00 a01 a02 a03 a10 a11 a12 a13 a20 a21 a22 a23 a30 a31 a32 a33
+ *
+ * Converting input bytes from two AES blocks to bitslice representation
+ * is done in the following way:
+ * -- Decode first block into the four words q0 q2 q4 q6, in that order,
+ * using little-endian convention.
+ * -- Decode second block into the four words q1 q3 q5 q7, in that order,
+ * using little-endian convention.
+ * -- Call aes_ct_ortho().
+ *
+ * Converting back to bytes is done by using the reverse operations. Note
+ * that aes_ct_ortho() is its own inverse.
+ */
+
+/*
+ * The AES S-box, as a bitsliced constant-time version. The input array
+ * consists in eight 32-bit words; 32 S-box instances are computed in
+ * parallel. Bits 0 to 7 of each S-box input (bit 0 is least significant)
+ * are spread over the words 0 to 7, at the same rank.
+ */
+static void
+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;
+}
+
+/*
+ * Perform bytewise orthogonalization of eight 32-bit words. Bytes
+ * of q0..q7 are spread over all words: for a byte x that occurs
+ * at rank i in q[j] (byte x uses bits 8*i to 8*i+7 in q[j]), the bit
+ * of rank k in x (0 <= k <= 7) goes to q[k] at rank 8*i+j.
+ *
+ * This operation is an involution.
+ */
+static void
+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 inline uint32_t
+sub_word(uint32_t x)
+{
+ uint32_t q[8];
+ int i;
+
+ for (i = 0; i < 8; i ++) {
+ q[i] = x;
+ }
+ aes_ct_ortho(q);
+ aes_ct_bitslice_Sbox(q);
+ aes_ct_ortho(q);
+ return q[0];
+}
+
+static const unsigned char Rcon[] = {
+ 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36
+};
+
+/*
+ * Base key schedule code. The function sub_word() must be defined
+ * below. Subkeys are produced in little-endian convention (but not
+ * bitsliced). Key length is expressed in bytes.
+ */
+static unsigned
+aes_keysched_base(uint32_t *skey, const void *key, size_t key_len)
+{
+ unsigned num_rounds;
+ int i, j, k, nk, nkf;
+ uint32_t tmp;
+
+ switch (key_len) {
+ case 16:
+ num_rounds = 10;
+ break;
+ case 24:
+ num_rounds = 12;
+ break;
+ case 32:
+ num_rounds = 14;
+ break;
+ default:
+ return 0;
+ }
+ nk = (int)(key_len >> 2);
+ nkf = (int)((num_rounds + 1) << 2);
+ for (i = 0; i < nk; i ++) {
+ tmp = dec32le((const unsigned char *)key + (i << 2));
+ skey[i] = tmp;
+ }
+ 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 ++;
+ }
+ }
+ return num_rounds;
+}
+
+/*
+ * AES key schedule, constant-time version. skey[] is filled with n+1
+ * 128-bit subkeys, where n is the number of rounds (10 to 14, depending
+ * on key size). The number of rounds is returned. If the key size is
+ * invalid (not 16, 24 or 32), then 0 is returned.
+ */
+unsigned
+aes_ct_keysched(uint32_t *comp_skey, const void *key, size_t key_len)
+{
+ uint32_t skey[60];
+ unsigned u, num_rounds;
+
+ num_rounds = aes_keysched_base(skey, key, key_len);
+ for (u = 0; u <= num_rounds; u ++) {
+ uint32_t q[8];
+
+ q[0] = q[1] = skey[(u << 2) + 0];
+ q[2] = q[3] = skey[(u << 2) + 1];
+ q[4] = q[5] = skey[(u << 2) + 2];
+ q[6] = q[7] = skey[(u << 2) + 3];
+ aes_ct_ortho(q);
+ comp_skey[(u << 2) + 0] =
+ (q[0] & 0x55555555) | (q[1] & 0xAAAAAAAA);
+ comp_skey[(u << 2) + 1] =
+ (q[2] & 0x55555555) | (q[3] & 0xAAAAAAAA);
+ comp_skey[(u << 2) + 2] =
+ (q[4] & 0x55555555) | (q[5] & 0xAAAAAAAA);
+ comp_skey[(u << 2) + 3] =
+ (q[6] & 0x55555555) | (q[7] & 0xAAAAAAAA);
+ }
+ return num_rounds;
+}
+
+/*
+ * Expand AES subkeys as produced by aes_ct_keysched(), into
+ * a larger array suitable for aes_ct_bitslice_encrypt() and
+ * aes_ct_bitslice_decrypt().
+ */
+void
+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);
+ }
+}
+
+static inline void
+add_round_key(uint32_t *q, const uint32_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(uint32_t *q)
+{
+ int i;
+
+ for (i = 0; i < 8; i ++) {
+ uint32_t x;
+
+ x = q[i];
+ q[i] = (x & 0x000000FF)
+ | ((x & 0x0000FC00) >> 2) | ((x & 0x00000300) << 6)
+ | ((x & 0x00F00000) >> 4) | ((x & 0x000F0000) << 4)
+ | ((x & 0xC0000000) >> 6) | ((x & 0x3F000000) << 2);
+ }
+}
+
+static inline uint32_t
+rotr16(uint32_t x)
+{
+ return (x << 16) | (x >> 16);
+}
+
+static inline void
+mix_columns(uint32_t *q)
+{
+ uint32_t q0, q1, q2, q3, q4, q5, q6, q7;
+ uint32_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 >> 8) | (q0 << 24);
+ r1 = (q1 >> 8) | (q1 << 24);
+ r2 = (q2 >> 8) | (q2 << 24);
+ r3 = (q3 >> 8) | (q3 << 24);
+ r4 = (q4 >> 8) | (q4 << 24);
+ r5 = (q5 >> 8) | (q5 << 24);
+ r6 = (q6 >> 8) | (q6 << 24);
+ r7 = (q7 >> 8) | (q7 << 24);
+
+ q[0] = q7 ^ r7 ^ r0 ^ rotr16(q0 ^ r0);
+ q[1] = q0 ^ r0 ^ q7 ^ r7 ^ r1 ^ rotr16(q1 ^ r1);
+ q[2] = q1 ^ r1 ^ r2 ^ rotr16(q2 ^ r2);
+ q[3] = q2 ^ r2 ^ q7 ^ r7 ^ r3 ^ rotr16(q3 ^ r3);
+ q[4] = q3 ^ r3 ^ q7 ^ r7 ^ r4 ^ rotr16(q4 ^ r4);
+ q[5] = q4 ^ r4 ^ r5 ^ rotr16(q5 ^ r5);
+ q[6] = q5 ^ r5 ^ r6 ^ rotr16(q6 ^ r6);
+ q[7] = q6 ^ r6 ^ r7 ^ rotr16(q7 ^ r7);
+}
+
+/*
+ * Compute AES encryption on bitsliced data. Since input is stored on
+ * eight 32-bit words, two block encryptions are actually performed
+ * in parallel.
+ */
+void
+aes_ct_bitslice_encrypt(unsigned num_rounds,
+ const uint32_t *skey, uint32_t *q)
+{
+ unsigned u;
+
+ add_round_key(q, skey);
+ for (u = 1; u < num_rounds; u ++) {
+ aes_ct_bitslice_Sbox(q);
+ shift_rows(q);
+ mix_columns(q);
+ add_round_key(q, skey + (u << 3));
+ }
+ aes_ct_bitslice_Sbox(q);
+ shift_rows(q);
+ add_round_key(q, skey + (num_rounds << 3));
+}
+
+/*
+ * Like aes_ct_bitslice_Sbox(), but for the inverse S-box.
+ */
+void
+aes_ct_bitslice_invSbox(uint32_t *q)
+{
+ /*
+ * AES S-box is:
+ * S(x) = A(I(x)) ^ 0x63
+ * where I() is inversion in GF(256), and A() is a linear
+ * transform (0 is formally defined to be its own inverse).
+ * Since inversion is an involution, the inverse S-box can be
+ * computed from the S-box as:
+ * iS(x) = B(S(B(x ^ 0x63)) ^ 0x63)
+ * where B() is the inverse of A(). Indeed, for any y in GF(256):
+ * iS(S(y)) = B(A(I(B(A(I(y)) ^ 0x63 ^ 0x63))) ^ 0x63 ^ 0x63) = y
+ *
+ * Note: we reuse the implementation of the forward S-box,
+ * instead of duplicating it here, so that total code size is
+ * lower. By merging the B() transforms into the S-box circuit
+ * we could make faster CBC decryption, but CBC decryption is
+ * already quite faster than CBC encryption because we can
+ * process two blocks in parallel.
+ */
+ uint32_t q0, q1, q2, q3, q4, q5, q6, q7;
+
+ q0 = ~q[0];
+ q1 = ~q[1];
+ q2 = q[2];
+ q3 = q[3];
+ q4 = q[4];
+ q5 = ~q[5];
+ q6 = ~q[6];
+ q7 = q[7];
+ q[7] = q1 ^ q4 ^ q6;
+ q[6] = q0 ^ q3 ^ q5;
+ q[5] = q7 ^ q2 ^ q4;
+ q[4] = q6 ^ q1 ^ q3;
+ q[3] = q5 ^ q0 ^ q2;
+ q[2] = q4 ^ q7 ^ q1;
+ q[1] = q3 ^ q6 ^ q0;
+ q[0] = q2 ^ q5 ^ q7;
+
+ aes_ct_bitslice_Sbox(q);
+
+ q0 = ~q[0];
+ q1 = ~q[1];
+ q2 = q[2];
+ q3 = q[3];
+ q4 = q[4];
+ q5 = ~q[5];
+ q6 = ~q[6];
+ q7 = q[7];
+ q[7] = q1 ^ q4 ^ q6;
+ q[6] = q0 ^ q3 ^ q5;
+ q[5] = q7 ^ q2 ^ q4;
+ q[4] = q6 ^ q1 ^ q3;
+ q[3] = q5 ^ q0 ^ q2;
+ q[2] = q4 ^ q7 ^ q1;
+ q[1] = q3 ^ q6 ^ q0;
+ q[0] = q2 ^ q5 ^ q7;
+}
+
+static inline void
+inv_shift_rows(uint32_t *q)
+{
+ int i;
+
+ for (i = 0; i < 8; i ++) {
+ uint32_t x;
+
+ x = q[i];
+ q[i] = (x & 0x000000FF)
+ | ((x & 0x00003F00) << 2) | ((x & 0x0000C000) >> 6)
+ | ((x & 0x000F0000) << 4) | ((x & 0x00F00000) >> 4)
+ | ((x & 0x03000000) << 6) | ((x & 0xFC000000) >> 2);
+ }
+}
+
+static void
+inv_mix_columns(uint32_t *q)
+{
+ uint32_t q0, q1, q2, q3, q4, q5, q6, q7;
+ uint32_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 >> 8) | (q0 << 24);
+ r1 = (q1 >> 8) | (q1 << 24);
+ r2 = (q2 >> 8) | (q2 << 24);
+ r3 = (q3 >> 8) | (q3 << 24);
+ r4 = (q4 >> 8) | (q4 << 24);
+ r5 = (q5 >> 8) | (q5 << 24);
+ r6 = (q6 >> 8) | (q6 << 24);
+ r7 = (q7 >> 8) | (q7 << 24);
+
+ q[0] = q5 ^ q6 ^ q7 ^ r0 ^ r5 ^ r7 ^ rotr16(q0 ^ q5 ^ q6 ^ r0 ^ r5);
+ q[1] = q0 ^ q5 ^ r0 ^ r1 ^ r5 ^ r6 ^ r7 ^ rotr16(q1 ^ q5 ^ q7 ^ r1 ^ r5 ^ r6);
+ q[2] = q0 ^ q1 ^ q6 ^ r1 ^ r2 ^ r6 ^ r7 ^ rotr16(q0 ^ q2 ^ q6 ^ r2 ^ r6 ^ r7);
+ q[3] = q0 ^ q1 ^ q2 ^ q5 ^ q6 ^ r0 ^ r2 ^ r3 ^ r5 ^ rotr16(q0 ^ q1 ^ q3 ^ q5 ^ q6 ^ q7 ^ r0 ^ r3 ^ r5 ^ r7);
+ q[4] = q1 ^ q2 ^ q3 ^ q5 ^ r1 ^ r3 ^ r4 ^ r5 ^ r6 ^ r7 ^ rotr16(q1 ^ q2 ^ q4 ^ q5 ^ q7 ^ r1 ^ r4 ^ r5 ^ r6);
+ q[5] = q2 ^ q3 ^ q4 ^ q6 ^ r2 ^ r4 ^ r5 ^ r6 ^ r7 ^ rotr16(q2 ^ q3 ^ q5 ^ q6 ^ r2 ^ r5 ^ r6 ^ r7);
+ q[6] = q3 ^ q4 ^ q5 ^ q7 ^ r3 ^ r5 ^ r6 ^ r7 ^ rotr16(q3 ^ q4 ^ q6 ^ q7 ^ r3 ^ r6 ^ r7);
+ q[7] = q4 ^ q5 ^ q6 ^ r4 ^ r6 ^ r7 ^ rotr16(q4 ^ q5 ^ q7 ^ r4 ^ r7);
+}
+
+/*
+ * Compute AES decryption on bitsliced data. Since input is stored on
+ * eight 32-bit words, two block decryptions are actually performed
+ * in parallel.
+ */
+void
+aes_ct_bitslice_decrypt(unsigned num_rounds,
+ const uint32_t *skey, uint32_t *q)
+{
+ unsigned u;
+
+ add_round_key(q, skey + (num_rounds << 3));
+ for (u = num_rounds - 1; u > 0; u --) {
+ inv_shift_rows(q);
+ aes_ct_bitslice_invSbox(q);
+ add_round_key(q, skey + (u << 3));
+ inv_mix_columns(q);
+ }
+ inv_shift_rows(q);
+ aes_ct_bitslice_invSbox(q);
+ add_round_key(q, skey);
+}
+
+
+int
+AES_Setkey(AES_CTX *ctx, const uint8_t *key, int len)
+{
+ ctx->num_rounds = aes_ct_keysched(ctx->sk, key, len);
+ if (ctx->num_rounds == 0)
+ return -1;
+ aes_ct_skey_expand(ctx->sk_exp, ctx->num_rounds, ctx->sk);
+ return 0;
+}
+
+void
+AES_Encrypt_ECB(AES_CTX *ctx, const uint8_t *src,
+ uint8_t *dst, size_t num_blocks)
+{
+ while (num_blocks > 0) {
+ uint32_t q[8];
+
+ q[0] = dec32le(src);
+ q[2] = dec32le(src + 4);
+ q[4] = dec32le(src + 8);
+ q[6] = dec32le(src + 12);
+ if (num_blocks > 1) {
+ q[1] = dec32le(src + 16);
+ q[3] = dec32le(src + 20);
+ q[5] = dec32le(src + 24);
+ q[7] = dec32le(src + 28);
+ } else {
+ q[1] = 0;
+ q[3] = 0;
+ q[5] = 0;
+ q[7] = 0;
+ }
+ aes_ct_ortho(q);
+ aes_ct_bitslice_encrypt(ctx->num_rounds, ctx->sk_exp, q);
+ aes_ct_ortho(q);
+ enc32le(dst, q[0]);
+ enc32le(dst + 4, q[2]);
+ enc32le(dst + 8, q[4]);
+ enc32le(dst + 12, q[6]);
+ if (num_blocks > 1) {
+ enc32le(dst + 16, q[1]);
+ enc32le(dst + 20, q[3]);
+ enc32le(dst + 24, q[5]);
+ enc32le(dst + 28, q[7]);
+ src += 32;
+ dst += 32;
+ num_blocks -= 2;
+ } else {
+ break;
+ }
+ }
+}
+
+void
+AES_Decrypt_ECB(AES_CTX *ctx, const uint8_t *src,
+ uint8_t *dst, size_t num_blocks)
+{
+ while (num_blocks > 0) {
+ uint32_t q[8];
+
+ q[0] = dec32le(src);
+ q[2] = dec32le(src + 4);
+ q[4] = dec32le(src + 8);
+ q[6] = dec32le(src + 12);
+ if (num_blocks > 1) {
+ q[1] = dec32le(src + 16);
+ q[3] = dec32le(src + 20);
+ q[5] = dec32le(src + 24);
+ q[7] = dec32le(src + 28);
+ } else {
+ q[1] = 0;
+ q[3] = 0;
+ q[5] = 0;
+ q[7] = 0;
+ }
+ aes_ct_ortho(q);
+ aes_ct_bitslice_decrypt(ctx->num_rounds, ctx->sk_exp, q);
+ aes_ct_ortho(q);
+ enc32le(dst, q[0]);
+ enc32le(dst + 4, q[2]);
+ enc32le(dst + 8, q[4]);
+ enc32le(dst + 12, q[6]);
+ if (num_blocks > 1) {
+ enc32le(dst + 16, q[1]);
+ enc32le(dst + 20, q[3]);
+ enc32le(dst + 24, q[5]);
+ enc32le(dst + 28, q[7]);
+ src += 32;
+ dst += 32;
+ num_blocks -= 2;
+ } else {
+ break;
+ }
+ }
+}
+
+void
+AES_Encrypt(AES_CTX *ctx, const uint8_t *src, uint8_t *dst)
+{
+ AES_Encrypt_ECB(ctx, src, dst, 1);
+}
+
+void
+AES_Decrypt(AES_CTX *ctx, const uint8_t *src, uint8_t *dst)
+{
+ AES_Decrypt_ECB(ctx, src, dst, 1);
+}
+
+int
+AES_KeySetup_Encrypt(uint32_t *skey, const uint8_t *key, int len)
+{
+ unsigned r, u;
+ uint32_t tkey[60];
+
+ r = aes_keysched_base(tkey, key, len);
+ if (r == 0) {
+ return 0;
+ }
+ for (u = 0; u < ((r + 1) << 2); u ++) {
+ uint32_t w;
+
+ w = tkey[u];
+ skey[u] = (w << 24)
+ | ((w & 0x0000FF00) << 8)
+ | ((w & 0x00FF0000) >> 8)
+ | (w >> 24);
+ }
+ return r;
+}
+
+/*
+ * Reduce value x modulo polynomial x^8+x^4+x^3+x+1. This works as
+ * long as x fits on 12 bits at most.
+ */
+static inline uint32_t
+redgf256(uint32_t x)
+{
+ uint32_t h;
+
+ h = x >> 8;
+ return (x ^ h ^ (h << 1) ^ (h << 3) ^ (h << 4)) & 0xFF;
+}
+
+/*
+ * Multiplication by 0x09 in GF(256).
+ */
+static inline uint32_t
+mul9(uint32_t x)
+{
+ return redgf256(x ^ (x << 3));
+}
+
+/*
+ * Multiplication by 0x0B in GF(256).
+ */
+static inline uint32_t
+mulb(uint32_t x)
+{
+ return redgf256(x ^ (x << 1) ^ (x << 3));
+}
+
+/*
+ * Multiplication by 0x0D in GF(256).
+ */
+static inline uint32_t
+muld(uint32_t x)
+{
+ return redgf256(x ^ (x << 2) ^ (x << 3));
+}
+
+/*
+ * Multiplication by 0x0E in GF(256).
+ */
+static inline uint32_t
+mule(uint32_t x)
+{
+ return redgf256((x << 1) ^ (x << 2) ^ (x << 3));
+}
+
+int
+AES_KeySetup_Decrypt(uint32_t *skey, const uint8_t *key, int len)
+{
+ unsigned r, u;
+ uint32_t tkey[60];
+
+ /*
+ * Compute encryption subkeys. We get them in big-endian
+ * notation.
+ */
+ r = AES_KeySetup_Encrypt(tkey, key, len);
+ if (r == 0) {
+ return 0;
+ }
+
+ /*
+ * Copy the subkeys in reverse order. Also, apply InvMixColumns()
+ * on the subkeys (except first and last).
+ */
+ memcpy(skey + (r << 2), tkey, 4 * sizeof(uint32_t));
+ memcpy(skey, tkey + (r << 2), 4 * sizeof(uint32_t));
+ for (u = 4; u < (r << 2); u ++) {
+ uint32_t sk, sk0, sk1, sk2, sk3;
+ uint32_t tk, tk0, tk1, tk2, tk3;
+
+ sk = tkey[u];
+ sk0 = sk >> 24;
+ sk1 = (sk >> 16) & 0xFF;
+ sk2 = (sk >> 8) & 0xFF;
+ sk3 = sk & 0xFF;
+ tk0 = mule(sk0) ^ mulb(sk1) ^ muld(sk2) ^ mul9(sk3);
+ tk1 = mul9(sk0) ^ mule(sk1) ^ mulb(sk2) ^ muld(sk3);
+ tk2 = muld(sk0) ^ mul9(sk1) ^ mule(sk2) ^ mulb(sk3);
+ tk3 = mulb(sk0) ^ muld(sk1) ^ mul9(sk2) ^ mule(sk3);
+ tk = (tk0 << 24) ^ (tk1 << 16) ^ (tk2 << 8) ^ tk3;
+ skey[((r - (u >> 2)) << 2) + (u & 3)] = tk;
+ }
+
+ return r;
+}
projects / openbsd / commitdiff