cast256.c

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/**
 * @file cast256.c
 * @brief CAST-256 encryption algorithm
 *
 * @section License
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 *
 * Copyright (C) 2010-2024 Oryx Embedded SARL. All rights reserved.
 *
 * This file is part of CycloneCRYPTO Open.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * @author Oryx Embedded SARL (www.oryx-embedded.com)
 * @version 2.4.4
 **/
 
//Switch to the appropriate trace level
#define TRACE_LEVEL CRYPTO_TRACE_LEVEL
 
//Dependencies
#include "core/crypto.h"
#include "cipher/cast256.h"
 
//Check crypto library configuration
#if (CAST256_SUPPORT == ENABLED)
 
//Substitution boxes
#define S1(a, b) s1[(a >> (8 * b)) & 0xFF]
#define S2(a, b) s2[(a >> (8 * b)) & 0xFF]
#define S3(a, b) s3[(a >> (8 * b)) & 0xFF]
#define S4(a, b) s4[(a >> (8 * b)) & 0xFF]
 
//Type 1 round
#define F1(y, x, kr, km) \
{ \
   uint32_t t; \
   t = km + x; \
   t = ROL32(t, kr); \
   y ^= ((S1(t, 3) ^ S2(t, 2)) - S3(t, 1)) + S4(t, 0); \
}
 
//Type 2 round
#define F2(y, x, kr, km) \
{ \
   uint32_t t; \
   t = km ^ x; \
   t = ROL32(t, kr); \
   y ^= ((S1(t, 3) - S2(t, 2)) + S3(t, 1)) ^ S4(t, 0); \
}
 
//Type 3 round
#define F3(y, x, kr, km) \
{ \
   uint32_t t; \
   t = km - x; \
   t = ROL32(t, kr); \
   y ^= ((S1(t, 3) + S2(t, 2)) ^ S3(t, 1)) - S4(t, 0); \
}
 
//Forward quad-round
#define Q(a, b, c, d, kr, km) \
{ \
   F1(c, d, kr[0], km[0]); \
   F2(b, c, kr[1], km[1]); \
   F3(a, b, kr[2], km[2]); \
   F1(d, a, kr[3], km[3]); \
}
 
//Reverse quad-round
#define QBAR(a, b, c, d, kr, km) \
{ \
   F1(d, a, kr[3], km[3]); \
   F3(a, b, kr[2], km[2]); \
   F2(b, c, kr[1], km[1]); \
   F1(c, d, kr[0], km[0]); \
}
 
//Forward octave
#define W(a, b, c, d, e, f, g, h, tr, tm) \
{ \
   F1(g, h, tr[0], tm[0]); \
   F2(f, g, tr[1], tm[1]); \
   F3(e, f, tr[2], tm[2]); \
   F1(d, e, tr[3], tm[3]); \
   F2(c, d, tr[4], tm[4]); \
   F3(b, c, tr[5], tm[5]); \
   F1(a, b, tr[6], tm[6]); \
   F2(h, a, tr[7], tm[7]); \
}
 
//Tr (precalculated table)
static const uint8_t tr[4][8] =
{
   {0x13, 0x04, 0x15, 0x06, 0x17, 0x08, 0x19, 0x0A},
   {0x1B, 0x0C, 0x1D, 0x0E, 0x1F, 0x10, 0x01, 0x12},
   {0x03, 0x14, 0x05, 0x16, 0x07, 0x18, 0x09, 0x1A},
   {0x0B, 0x1C, 0x0D, 0x1E, 0x0F, 0x00, 0x11, 0x02}
};
 
//Tm (precalculated table)
static const uint32_t tm[24][8] =
{
   {0x5A827999, 0xC95C653A, 0x383650DB, 0xA7103C7C, 0x15EA281D, 0x84C413BE, 0xF39DFF5F, 0x6277EB00},
   {0xD151D6A1, 0x402BC242, 0xAF05ADE3, 0x1DDF9984, 0x8CB98525, 0xFB9370C6, 0x6A6D5C67, 0xD9474808},
   {0x482133A9, 0xB6FB1F4A, 0x25D50AEB, 0x94AEF68C, 0x0388E22D, 0x7262CDCE, 0xE13CB96F, 0x5016A510},
   {0xBEF090B1, 0x2DCA7C52, 0x9CA467F3, 0x0B7E5394, 0x7A583F35, 0xE9322AD6, 0x580C1677, 0xC6E60218},
   {0x35BFEDB9, 0xA499D95A, 0x1373C4FB, 0x824DB09C, 0xF1279C3D, 0x600187DE, 0xCEDB737F, 0x3DB55F20},
   {0xAC8F4AC1, 0x1B693662, 0x8A432203, 0xF91D0DA4, 0x67F6F945, 0xD6D0E4E6, 0x45AAD087, 0xB484BC28},
   {0x235EA7C9, 0x9238936A, 0x01127F0B, 0x6FEC6AAC, 0xDEC6564D, 0x4DA041EE, 0xBC7A2D8F, 0x2B541930},
   {0x9A2E04D1, 0x0907F072, 0x77E1DC13, 0xE6BBC7B4, 0x5595B355, 0xC46F9EF6, 0x33498A97, 0xA2237638},
   {0x10FD61D9, 0x7FD74D7A, 0xEEB1391B, 0x5D8B24BC, 0xCC65105D, 0x3B3EFBFE, 0xAA18E79F, 0x18F2D340},
   {0x87CCBEE1, 0xF6A6AA82, 0x65809623, 0xD45A81C4, 0x43346D65, 0xB20E5906, 0x20E844A7, 0x8FC23048},
   {0xFE9C1BE9, 0x6D76078A, 0xDC4FF32B, 0x4B29DECC, 0xBA03CA6D, 0x28DDB60E, 0x97B7A1AF, 0x06918D50},
   {0x756B78F1, 0xE4456492, 0x531F5033, 0xC1F93BD4, 0x30D32775, 0x9FAD1316, 0x0E86FEB7, 0x7D60EA58},
   {0xEC3AD5F9, 0x5B14C19A, 0xC9EEAD3B, 0x38C898DC, 0xA7A2847D, 0x167C701E, 0x85565BBF, 0xF4304760},
   {0x630A3301, 0xD1E41EA2, 0x40BE0A43, 0xAF97F5E4, 0x1E71E185, 0x8D4BCD26, 0xFC25B8C7, 0x6AFFA468},
   {0xD9D99009, 0x48B37BAA, 0xB78D674B, 0x266752EC, 0x95413E8D, 0x041B2A2E, 0x72F515CF, 0xE1CF0170},
   {0x50A8ED11, 0xBF82D8B2, 0x2E5CC453, 0x9D36AFF4, 0x0C109B95, 0x7AEA8736, 0xE9C472D7, 0x589E5E78},
   {0xC7784A19, 0x365235BA, 0xA52C215B, 0x14060CFC, 0x82DFF89D, 0xF1B9E43E, 0x6093CFDF, 0xCF6DBB80},
   {0x3E47A721, 0xAD2192C2, 0x1BFB7E63, 0x8AD56A04, 0xF9AF55A5, 0x68894146, 0xD7632CE7, 0x463D1888},
   {0xB5170429, 0x23F0EFCA, 0x92CADB6B, 0x01A4C70C, 0x707EB2AD, 0xDF589E4E, 0x4E3289EF, 0xBD0C7590},
   {0x2BE66131, 0x9AC04CD2, 0x099A3873, 0x78742414, 0xE74E0FB5, 0x5627FB56, 0xC501E6F7, 0x33DBD298},
   {0xA2B5BE39, 0x118FA9DA, 0x8069957B, 0xEF43811C, 0x5E1D6CBD, 0xCCF7585E, 0x3BD143FF, 0xAAAB2FA0},
   {0x19851B41, 0x885F06E2, 0xF738F283, 0x6612DE24, 0xD4ECC9C5, 0x43C6B566, 0xB2A0A107, 0x217A8CA8},
   {0x90547849, 0xFF2E63EA, 0x6E084F8B, 0xDCE23B2C, 0x4BBC26CD, 0xBA96126E, 0x296FFE0F, 0x9849E9B0},
   {0x0723D551, 0x75FDC0F2, 0xE4D7AC93, 0x53B19834, 0xC28B83D5, 0x31656F76, 0xA03F5B17, 0x0F1946B8}
};
 
//S-box S1
static const uint32_t s1[256] =
{
   0x30FB40D4, 0x9FA0FF0B, 0x6BECCD2F, 0x3F258C7A, 0x1E213F2F, 0x9C004DD3, 0x6003E540, 0xCF9FC949,
   0xBFD4AF27, 0x88BBBDB5, 0xE2034090, 0x98D09675, 0x6E63A0E0, 0x15C361D2, 0xC2E7661D, 0x22D4FF8E,
   0x28683B6F, 0xC07FD059, 0xFF2379C8, 0x775F50E2, 0x43C340D3, 0xDF2F8656, 0x887CA41A, 0xA2D2BD2D,
   0xA1C9E0D6, 0x346C4819, 0x61B76D87, 0x22540F2F, 0x2ABE32E1, 0xAA54166B, 0x22568E3A, 0xA2D341D0,
   0x66DB40C8, 0xA784392F, 0x004DFF2F, 0x2DB9D2DE, 0x97943FAC, 0x4A97C1D8, 0x527644B7, 0xB5F437A7,
   0xB82CBAEF, 0xD751D159, 0x6FF7F0ED, 0x5A097A1F, 0x827B68D0, 0x90ECF52E, 0x22B0C054, 0xBC8E5935,
   0x4B6D2F7F, 0x50BB64A2, 0xD2664910, 0xBEE5812D, 0xB7332290, 0xE93B159F, 0xB48EE411, 0x4BFF345D,
   0xFD45C240, 0xAD31973F, 0xC4F6D02E, 0x55FC8165, 0xD5B1CAAD, 0xA1AC2DAE, 0xA2D4B76D, 0xC19B0C50,
   0x882240F2, 0x0C6E4F38, 0xA4E4BFD7, 0x4F5BA272, 0x564C1D2F, 0xC59C5319, 0xB949E354, 0xB04669FE,
   0xB1B6AB8A, 0xC71358DD, 0x6385C545, 0x110F935D, 0x57538AD5, 0x6A390493, 0xE63D37E0, 0x2A54F6B3,
   0x3A787D5F, 0x6276A0B5, 0x19A6FCDF, 0x7A42206A, 0x29F9D4D5, 0xF61B1891, 0xBB72275E, 0xAA508167,
   0x38901091, 0xC6B505EB, 0x84C7CB8C, 0x2AD75A0F, 0x874A1427, 0xA2D1936B, 0x2AD286AF, 0xAA56D291,
   0xD7894360, 0x425C750D, 0x93B39E26, 0x187184C9, 0x6C00B32D, 0x73E2BB14, 0xA0BEBC3C, 0x54623779,
   0x64459EAB, 0x3F328B82, 0x7718CF82, 0x59A2CEA6, 0x04EE002E, 0x89FE78E6, 0x3FAB0950, 0x325FF6C2,
   0x81383F05, 0x6963C5C8, 0x76CB5AD6, 0xD49974C9, 0xCA180DCF, 0x380782D5, 0xC7FA5CF6, 0x8AC31511,
   0x35E79E13, 0x47DA91D0, 0xF40F9086, 0xA7E2419E, 0x31366241, 0x051EF495, 0xAA573B04, 0x4A805D8D,
   0x548300D0, 0x00322A3C, 0xBF64CDDF, 0xBA57A68E, 0x75C6372B, 0x50AFD341, 0xA7C13275, 0x915A0BF5,
   0x6B54BFAB, 0x2B0B1426, 0xAB4CC9D7, 0x449CCD82, 0xF7FBF265, 0xAB85C5F3, 0x1B55DB94, 0xAAD4E324,
   0xCFA4BD3F, 0x2DEAA3E2, 0x9E204D02, 0xC8BD25AC, 0xEADF55B3, 0xD5BD9E98, 0xE31231B2, 0x2AD5AD6C,
   0x954329DE, 0xADBE4528, 0xD8710F69, 0xAA51C90F, 0xAA786BF6, 0x22513F1E, 0xAA51A79B, 0x2AD344CC,
   0x7B5A41F0, 0xD37CFBAD, 0x1B069505, 0x41ECE491, 0xB4C332E6, 0x032268D4, 0xC9600ACC, 0xCE387E6D,
   0xBF6BB16C, 0x6A70FB78, 0x0D03D9C9, 0xD4DF39DE, 0xE01063DA, 0x4736F464, 0x5AD328D8, 0xB347CC96,
   0x75BB0FC3, 0x98511BFB, 0x4FFBCC35, 0xB58BCF6A, 0xE11F0ABC, 0xBFC5FE4A, 0xA70AEC10, 0xAC39570A,
   0x3F04442F, 0x6188B153, 0xE0397A2E, 0x5727CB79, 0x9CEB418F, 0x1CACD68D, 0x2AD37C96, 0x0175CB9D,
   0xC69DFF09, 0xC75B65F0, 0xD9DB40D8, 0xEC0E7779, 0x4744EAD4, 0xB11C3274, 0xDD24CB9E, 0x7E1C54BD,
   0xF01144F9, 0xD2240EB1, 0x9675B3FD, 0xA3AC3755, 0xD47C27AF, 0x51C85F4D, 0x56907596, 0xA5BB15E6,
   0x580304F0, 0xCA042CF1, 0x011A37EA, 0x8DBFAADB, 0x35BA3E4A, 0x3526FFA0, 0xC37B4D09, 0xBC306ED9,
   0x98A52666, 0x5648F725, 0xFF5E569D, 0x0CED63D0, 0x7C63B2CF, 0x700B45E1, 0xD5EA50F1, 0x85A92872,
   0xAF1FBDA7, 0xD4234870, 0xA7870BF3, 0x2D3B4D79, 0x42E04198, 0x0CD0EDE7, 0x26470DB8, 0xF881814C,
   0x474D6AD7, 0x7C0C5E5C, 0xD1231959, 0x381B7298, 0xF5D2F4DB, 0xAB838653, 0x6E2F1E23, 0x83719C9E,
   0xBD91E046, 0x9A56456E, 0xDC39200C, 0x20C8C571, 0x962BDA1C, 0xE1E696FF, 0xB141AB08, 0x7CCA89B9,
   0x1A69E783, 0x02CC4843, 0xA2F7C579, 0x429EF47D, 0x427B169C, 0x5AC9F049, 0xDD8F0F00, 0x5C8165BF
};
 
//S-box S2
static const uint32_t s2[256] =
{
   0x1F201094, 0xEF0BA75B, 0x69E3CF7E, 0x393F4380, 0xFE61CF7A, 0xEEC5207A, 0x55889C94, 0x72FC0651,
   0xADA7EF79, 0x4E1D7235, 0xD55A63CE, 0xDE0436BA, 0x99C430EF, 0x5F0C0794, 0x18DCDB7D, 0xA1D6EFF3,
   0xA0B52F7B, 0x59E83605, 0xEE15B094, 0xE9FFD909, 0xDC440086, 0xEF944459, 0xBA83CCB3, 0xE0C3CDFB,
   0xD1DA4181, 0x3B092AB1, 0xF997F1C1, 0xA5E6CF7B, 0x01420DDB, 0xE4E7EF5B, 0x25A1FF41, 0xE180F806,
   0x1FC41080, 0x179BEE7A, 0xD37AC6A9, 0xFE5830A4, 0x98DE8B7F, 0x77E83F4E, 0x79929269, 0x24FA9F7B,
   0xE113C85B, 0xACC40083, 0xD7503525, 0xF7EA615F, 0x62143154, 0x0D554B63, 0x5D681121, 0xC866C359,
   0x3D63CF73, 0xCEE234C0, 0xD4D87E87, 0x5C672B21, 0x071F6181, 0x39F7627F, 0x361E3084, 0xE4EB573B,
   0x602F64A4, 0xD63ACD9C, 0x1BBC4635, 0x9E81032D, 0x2701F50C, 0x99847AB4, 0xA0E3DF79, 0xBA6CF38C,
   0x10843094, 0x2537A95E, 0xF46F6FFE, 0xA1FF3B1F, 0x208CFB6A, 0x8F458C74, 0xD9E0A227, 0x4EC73A34,
   0xFC884F69, 0x3E4DE8DF, 0xEF0E0088, 0x3559648D, 0x8A45388C, 0x1D804366, 0x721D9BFD, 0xA58684BB,
   0xE8256333, 0x844E8212, 0x128D8098, 0xFED33FB4, 0xCE280AE1, 0x27E19BA5, 0xD5A6C252, 0xE49754BD,
   0xC5D655DD, 0xEB667064, 0x77840B4D, 0xA1B6A801, 0x84DB26A9, 0xE0B56714, 0x21F043B7, 0xE5D05860,
   0x54F03084, 0x066FF472, 0xA31AA153, 0xDADC4755, 0xB5625DBF, 0x68561BE6, 0x83CA6B94, 0x2D6ED23B,
   0xECCF01DB, 0xA6D3D0BA, 0xB6803D5C, 0xAF77A709, 0x33B4A34C, 0x397BC8D6, 0x5EE22B95, 0x5F0E5304,
   0x81ED6F61, 0x20E74364, 0xB45E1378, 0xDE18639B, 0x881CA122, 0xB96726D1, 0x8049A7E8, 0x22B7DA7B,
   0x5E552D25, 0x5272D237, 0x79D2951C, 0xC60D894C, 0x488CB402, 0x1BA4FE5B, 0xA4B09F6B, 0x1CA815CF,
   0xA20C3005, 0x8871DF63, 0xB9DE2FCB, 0x0CC6C9E9, 0x0BEEFF53, 0xE3214517, 0xB4542835, 0x9F63293C,
   0xEE41E729, 0x6E1D2D7C, 0x50045286, 0x1E6685F3, 0xF33401C6, 0x30A22C95, 0x31A70850, 0x60930F13,
   0x73F98417, 0xA1269859, 0xEC645C44, 0x52C877A9, 0xCDFF33A6, 0xA02B1741, 0x7CBAD9A2, 0x2180036F,
   0x50D99C08, 0xCB3F4861, 0xC26BD765, 0x64A3F6AB, 0x80342676, 0x25A75E7B, 0xE4E6D1FC, 0x20C710E6,
   0xCDF0B680, 0x17844D3B, 0x31EEF84D, 0x7E0824E4, 0x2CCB49EB, 0x846A3BAE, 0x8FF77888, 0xEE5D60F6,
   0x7AF75673, 0x2FDD5CDB, 0xA11631C1, 0x30F66F43, 0xB3FAEC54, 0x157FD7FA, 0xEF8579CC, 0xD152DE58,
   0xDB2FFD5E, 0x8F32CE19, 0x306AF97A, 0x02F03EF8, 0x99319AD5, 0xC242FA0F, 0xA7E3EBB0, 0xC68E4906,
   0xB8DA230C, 0x80823028, 0xDCDEF3C8, 0xD35FB171, 0x088A1BC8, 0xBEC0C560, 0x61A3C9E8, 0xBCA8F54D,
   0xC72FEFFA, 0x22822E99, 0x82C570B4, 0xD8D94E89, 0x8B1C34BC, 0x301E16E6, 0x273BE979, 0xB0FFEAA6,
   0x61D9B8C6, 0x00B24869, 0xB7FFCE3F, 0x08DC283B, 0x43DAF65A, 0xF7E19798, 0x7619B72F, 0x8F1C9BA4,
   0xDC8637A0, 0x16A7D3B1, 0x9FC393B7, 0xA7136EEB, 0xC6BCC63E, 0x1A513742, 0xEF6828BC, 0x520365D6,
   0x2D6A77AB, 0x3527ED4B, 0x821FD216, 0x095C6E2E, 0xDB92F2FB, 0x5EEA29CB, 0x145892F5, 0x91584F7F,
   0x5483697B, 0x2667A8CC, 0x85196048, 0x8C4BACEA, 0x833860D4, 0x0D23E0F9, 0x6C387E8A, 0x0AE6D249,
   0xB284600C, 0xD835731D, 0xDCB1C647, 0xAC4C56EA, 0x3EBD81B3, 0x230EABB0, 0x6438BC87, 0xF0B5B1FA,
   0x8F5EA2B3, 0xFC184642, 0x0A036B7A, 0x4FB089BD, 0x649DA589, 0xA345415E, 0x5C038323, 0x3E5D3BB9,
   0x43D79572, 0x7E6DD07C, 0x06DFDF1E, 0x6C6CC4EF, 0x7160A539, 0x73BFBE70, 0x83877605, 0x4523ECF1
};
 
//S-box S3
static const uint32_t s3[256] =
{
   0x8DEFC240, 0x25FA5D9F, 0xEB903DBF, 0xE810C907, 0x47607FFF, 0x369FE44B, 0x8C1FC644, 0xAECECA90,
   0xBEB1F9BF, 0xEEFBCAEA, 0xE8CF1950, 0x51DF07AE, 0x920E8806, 0xF0AD0548, 0xE13C8D83, 0x927010D5,
   0x11107D9F, 0x07647DB9, 0xB2E3E4D4, 0x3D4F285E, 0xB9AFA820, 0xFADE82E0, 0xA067268B, 0x8272792E,
   0x553FB2C0, 0x489AE22B, 0xD4EF9794, 0x125E3FBC, 0x21FFFCEE, 0x825B1BFD, 0x9255C5ED, 0x1257A240,
   0x4E1A8302, 0xBAE07FFF, 0x528246E7, 0x8E57140E, 0x3373F7BF, 0x8C9F8188, 0xA6FC4EE8, 0xC982B5A5,
   0xA8C01DB7, 0x579FC264, 0x67094F31, 0xF2BD3F5F, 0x40FFF7C1, 0x1FB78DFC, 0x8E6BD2C1, 0x437BE59B,
   0x99B03DBF, 0xB5DBC64B, 0x638DC0E6, 0x55819D99, 0xA197C81C, 0x4A012D6E, 0xC5884A28, 0xCCC36F71,
   0xB843C213, 0x6C0743F1, 0x8309893C, 0x0FEDDD5F, 0x2F7FE850, 0xD7C07F7E, 0x02507FBF, 0x5AFB9A04,
   0xA747D2D0, 0x1651192E, 0xAF70BF3E, 0x58C31380, 0x5F98302E, 0x727CC3C4, 0x0A0FB402, 0x0F7FEF82,
   0x8C96FDAD, 0x5D2C2AAE, 0x8EE99A49, 0x50DA88B8, 0x8427F4A0, 0x1EAC5790, 0x796FB449, 0x8252DC15,
   0xEFBD7D9B, 0xA672597D, 0xADA840D8, 0x45F54504, 0xFA5D7403, 0xE83EC305, 0x4F91751A, 0x925669C2,
   0x23EFE941, 0xA903F12E, 0x60270DF2, 0x0276E4B6, 0x94FD6574, 0x927985B2, 0x8276DBCB, 0x02778176,
   0xF8AF918D, 0x4E48F79E, 0x8F616DDF, 0xE29D840E, 0x842F7D83, 0x340CE5C8, 0x96BBB682, 0x93B4B148,
   0xEF303CAB, 0x984FAF28, 0x779FAF9B, 0x92DC560D, 0x224D1E20, 0x8437AA88, 0x7D29DC96, 0x2756D3DC,
   0x8B907CEE, 0xB51FD240, 0xE7C07CE3, 0xE566B4A1, 0xC3E9615E, 0x3CF8209D, 0x6094D1E3, 0xCD9CA341,
   0x5C76460E, 0x00EA983B, 0xD4D67881, 0xFD47572C, 0xF76CEDD9, 0xBDA8229C, 0x127DADAA, 0x438A074E,
   0x1F97C090, 0x081BDB8A, 0x93A07EBE, 0xB938CA15, 0x97B03CFF, 0x3DC2C0F8, 0x8D1AB2EC, 0x64380E51,
   0x68CC7BFB, 0xD90F2788, 0x12490181, 0x5DE5FFD4, 0xDD7EF86A, 0x76A2E214, 0xB9A40368, 0x925D958F,
   0x4B39FFFA, 0xBA39AEE9, 0xA4FFD30B, 0xFAF7933B, 0x6D498623, 0x193CBCFA, 0x27627545, 0x825CF47A,
   0x61BD8BA0, 0xD11E42D1, 0xCEAD04F4, 0x127EA392, 0x10428DB7, 0x8272A972, 0x9270C4A8, 0x127DE50B,
   0x285BA1C8, 0x3C62F44F, 0x35C0EAA5, 0xE805D231, 0x428929FB, 0xB4FCDF82, 0x4FB66A53, 0x0E7DC15B,
   0x1F081FAB, 0x108618AE, 0xFCFD086D, 0xF9FF2889, 0x694BCC11, 0x236A5CAE, 0x12DECA4D, 0x2C3F8CC5,
   0xD2D02DFE, 0xF8EF5896, 0xE4CF52DA, 0x95155B67, 0x494A488C, 0xB9B6A80C, 0x5C8F82BC, 0x89D36B45,
   0x3A609437, 0xEC00C9A9, 0x44715253, 0x0A874B49, 0xD773BC40, 0x7C34671C, 0x02717EF6, 0x4FEB5536,
   0xA2D02FFF, 0xD2BF60C4, 0xD43F03C0, 0x50B4EF6D, 0x07478CD1, 0x006E1888, 0xA2E53F55, 0xB9E6D4BC,
   0xA2048016, 0x97573833, 0xD7207D67, 0xDE0F8F3D, 0x72F87B33, 0xABCC4F33, 0x7688C55D, 0x7B00A6B0,
   0x947B0001, 0x570075D2, 0xF9BB88F8, 0x8942019E, 0x4264A5FF, 0x856302E0, 0x72DBD92B, 0xEE971B69,
   0x6EA22FDE, 0x5F08AE2B, 0xAF7A616D, 0xE5C98767, 0xCF1FEBD2, 0x61EFC8C2, 0xF1AC2571, 0xCC8239C2,
   0x67214CB8, 0xB1E583D1, 0xB7DC3E62, 0x7F10BDCE, 0xF90A5C38, 0x0FF0443D, 0x606E6DC6, 0x60543A49,
   0x5727C148, 0x2BE98A1D, 0x8AB41738, 0x20E1BE24, 0xAF96DA0F, 0x68458425, 0x99833BE5, 0x600D457D,
   0x282F9350, 0x8334B362, 0xD91D1120, 0x2B6D8DA0, 0x642B1E31, 0x9C305A00, 0x52BCE688, 0x1B03588A,
   0xF7BAEFD5, 0x4142ED9C, 0xA4315C11, 0x83323EC5, 0xDFEF4636, 0xA133C501, 0xE9D3531C, 0xEE353783
};
 
//S-box S4
static const uint32_t s4[256] =
{
   0x9DB30420, 0x1FB6E9DE, 0xA7BE7BEF, 0xD273A298, 0x4A4F7BDB, 0x64AD8C57, 0x85510443, 0xFA020ED1,
   0x7E287AFF, 0xE60FB663, 0x095F35A1, 0x79EBF120, 0xFD059D43, 0x6497B7B1, 0xF3641F63, 0x241E4ADF,
   0x28147F5F, 0x4FA2B8CD, 0xC9430040, 0x0CC32220, 0xFDD30B30, 0xC0A5374F, 0x1D2D00D9, 0x24147B15,
   0xEE4D111A, 0x0FCA5167, 0x71FF904C, 0x2D195FFE, 0x1A05645F, 0x0C13FEFE, 0x081B08CA, 0x05170121,
   0x80530100, 0xE83E5EFE, 0xAC9AF4F8, 0x7FE72701, 0xD2B8EE5F, 0x06DF4261, 0xBB9E9B8A, 0x7293EA25,
   0xCE84FFDF, 0xF5718801, 0x3DD64B04, 0xA26F263B, 0x7ED48400, 0x547EEBE6, 0x446D4CA0, 0x6CF3D6F5,
   0x2649ABDF, 0xAEA0C7F5, 0x36338CC1, 0x503F7E93, 0xD3772061, 0x11B638E1, 0x72500E03, 0xF80EB2BB,
   0xABE0502E, 0xEC8D77DE, 0x57971E81, 0xE14F6746, 0xC9335400, 0x6920318F, 0x081DBB99, 0xFFC304A5,
   0x4D351805, 0x7F3D5CE3, 0xA6C866C6, 0x5D5BCCA9, 0xDAEC6FEA, 0x9F926F91, 0x9F46222F, 0x3991467D,
   0xA5BF6D8E, 0x1143C44F, 0x43958302, 0xD0214EEB, 0x022083B8, 0x3FB6180C, 0x18F8931E, 0x281658E6,
   0x26486E3E, 0x8BD78A70, 0x7477E4C1, 0xB506E07C, 0xF32D0A25, 0x79098B02, 0xE4EABB81, 0x28123B23,
   0x69DEAD38, 0x1574CA16, 0xDF871B62, 0x211C40B7, 0xA51A9EF9, 0x0014377B, 0x041E8AC8, 0x09114003,
   0xBD59E4D2, 0xE3D156D5, 0x4FE876D5, 0x2F91A340, 0x557BE8DE, 0x00EAE4A7, 0x0CE5C2EC, 0x4DB4BBA6,
   0xE756BDFF, 0xDD3369AC, 0xEC17B035, 0x06572327, 0x99AFC8B0, 0x56C8C391, 0x6B65811C, 0x5E146119,
   0x6E85CB75, 0xBE07C002, 0xC2325577, 0x893FF4EC, 0x5BBFC92D, 0xD0EC3B25, 0xB7801AB7, 0x8D6D3B24,
   0x20C763EF, 0xC366A5FC, 0x9C382880, 0x0ACE3205, 0xAAC9548A, 0xECA1D7C7, 0x041AFA32, 0x1D16625A,
   0x6701902C, 0x9B757A54, 0x31D477F7, 0x9126B031, 0x36CC6FDB, 0xC70B8B46, 0xD9E66A48, 0x56E55A79,
   0x026A4CEB, 0x52437EFF, 0x2F8F76B4, 0x0DF980A5, 0x8674CDE3, 0xEDDA04EB, 0x17A9BE04, 0x2C18F4DF,
   0xB7747F9D, 0xAB2AF7B4, 0xEFC34D20, 0x2E096B7C, 0x1741A254, 0xE5B6A035, 0x213D42F6, 0x2C1C7C26,
   0x61C2F50F, 0x6552DAF9, 0xD2C231F8, 0x25130F69, 0xD8167FA2, 0x0418F2C8, 0x001A96A6, 0x0D1526AB,
   0x63315C21, 0x5E0A72EC, 0x49BAFEFD, 0x187908D9, 0x8D0DBD86, 0x311170A7, 0x3E9B640C, 0xCC3E10D7,
   0xD5CAD3B6, 0x0CAEC388, 0xF73001E1, 0x6C728AFF, 0x71EAE2A1, 0x1F9AF36E, 0xCFCBD12F, 0xC1DE8417,
   0xAC07BE6B, 0xCB44A1D8, 0x8B9B0F56, 0x013988C3, 0xB1C52FCA, 0xB4BE31CD, 0xD8782806, 0x12A3A4E2,
   0x6F7DE532, 0x58FD7EB6, 0xD01EE900, 0x24ADFFC2, 0xF4990FC5, 0x9711AAC5, 0x001D7B95, 0x82E5E7D2,
   0x109873F6, 0x00613096, 0xC32D9521, 0xADA121FF, 0x29908415, 0x7FBB977F, 0xAF9EB3DB, 0x29C9ED2A,
   0x5CE2A465, 0xA730F32C, 0xD0AA3FE8, 0x8A5CC091, 0xD49E2CE7, 0x0CE454A9, 0xD60ACD86, 0x015F1919,
   0x77079103, 0xDEA03AF6, 0x78A8565E, 0xDEE356DF, 0x21F05CBE, 0x8B75E387, 0xB3C50651, 0xB8A5C3EF,
   0xD8EEB6D2, 0xE523BE77, 0xC2154529, 0x2F69EFDF, 0xAFE67AFB, 0xF470C4B2, 0xF3E0EB5B, 0xD6CC9876,
   0x39E4460C, 0x1FDA8538, 0x1987832F, 0xCA007367, 0xA99144F8, 0x296B299E, 0x492FC295, 0x9266BEAB,
   0xB5676E69, 0x9BD3DDDA, 0xDF7E052F, 0xDB25701C, 0x1B5E51EE, 0xF65324E6, 0x6AFCE36C, 0x0316CC04,
   0x8644213E, 0xB7DC59D0, 0x7965291F, 0xCCD6FD43, 0x41823979, 0x932BCDF6, 0xB657C34D, 0x4EDFD282,
   0x7AE5290C, 0x3CB9536B, 0x851E20FE, 0x9833557E, 0x13ECF0B0, 0xD3FFB372, 0x3F85C5C1, 0x0AEF7ED2
};
 
//Common interface for encryption algorithms
const CipherAlgo cast256CipherAlgo =
{
   "CAST-256",
   sizeof(Cast256Context),
   CIPHER_ALGO_TYPE_BLOCK,
   CAST256_BLOCK_SIZE,
   (CipherAlgoInit) cast256Init,
   NULL,
   NULL,
   (CipherAlgoEncryptBlock) cast256EncryptBlock,
   (CipherAlgoDecryptBlock) cast256DecryptBlock,
   (CipherAlgoDeinit) cast256Deinit
};
 
 
/**
 * @brief Key expansion
 * @param[in] context Pointer to the CAST-256 context to initialize
 * @param[in] key Pointer to the key
 * @param[in] keyLen Length of the key
 * @return Error code
 **/
 
error_t cast256Init(Cast256Context *context, const uint8_t *key, size_t keyLen)
{
   uint_t i;
   uint32_t a, b, c, d, e, f, g, h;
 
   //Check parameters
   if(context == NULL || key == NULL)
      return ERROR_INVALID_PARAMETER;
 
   //CAST-256 has a variable key size (128, 160, 192, 224, or 256 bits)
   if(keyLen < 16 || keyLen > 32 || (keyLen % 4) != 0)
      return ERROR_INVALID_KEY_LENGTH;
 
   //Let ABCDEFGH be the primary key K
   a = LOAD32BE(key);
   b = LOAD32BE(key + 4);
   c = LOAD32BE(key + 8);
   d = LOAD32BE(key + 12);
 
   //For key sizes less than 256 bits, the key is padded with zero bytes
   e = (keyLen >= 20) ? LOAD32BE(key + 16) : 0;
   f = (keyLen >= 24) ? LOAD32BE(key + 20) : 0;
   g = (keyLen >= 28) ? LOAD32BE(key + 24) : 0;
   h = (keyLen >= 32) ? LOAD32BE(key + 28) : 0;
 
   //Key schedule
   for(i = 0; i < 12; i++)
   {
      //Derive subkeys (refer to RFC 2612, section 2.4)
      W(a, b, c, d, e, f, g, h, tr[(2 * i) % 4], tm[2 * i]);
      W(a, b, c, d, e, f, g, h, tr[(2 * i + 1) % 4], tm[2 * i + 1]);
 
      //Save rotate subkeys Kr (only the 5 least significant bits are used)
      context->kr[i][0] = a & 0x1F;
      context->kr[i][1] = c & 0x1F;
      context->kr[i][2] = e & 0x1F;
      context->kr[i][3] = g & 0x1F;
 
      //Save masking subkeys Km
      context->km[i][0] = h;
      context->km[i][1] = f;
      context->km[i][2] = d;
      context->km[i][3] = b;
   }
 
   //No error to report
   return NO_ERROR;
}
 
 
/**
 * @brief Encrypt a 8-byte block using CAST-256 algorithm
 * @param[in] context Pointer to the CAST-256 context
 * @param[in] input Plaintext block to encrypt
 * @param[out] output Ciphertext block resulting from encryption
 **/
 
void cast256EncryptBlock(Cast256Context *context, const uint8_t *input,
   uint8_t *output)
{
   uint32_t a;
   uint32_t b;
   uint32_t c;
   uint32_t d;
 
   //The 16 bytes of plaintext are split into 4 words
   a = LOAD32BE(input + 0);
   b = LOAD32BE(input + 4);
   c = LOAD32BE(input + 8);
   d = LOAD32BE(input + 12);
 
   //CAST-256 has 48 rounds in 12 quad-rounds
   Q(a, b, c, d, context->kr[0], context->km[0]);
   Q(a, b, c, d, context->kr[1], context->km[1]);
   Q(a, b, c, d, context->kr[2], context->km[2]);
   Q(a, b, c, d, context->kr[3], context->km[3]);
   Q(a, b, c, d, context->kr[4], context->km[4]);
   Q(a, b, c, d, context->kr[5], context->km[5]);
 
   QBAR(a, b, c, d, context->kr[6], context->km[6]);
   QBAR(a, b, c, d, context->kr[7], context->km[7]);
   QBAR(a, b, c, d, context->kr[8], context->km[8]);
   QBAR(a, b, c, d, context->kr[9], context->km[9]);
   QBAR(a, b, c, d, context->kr[10], context->km[10]);
   QBAR(a, b, c, d, context->kr[11], context->km[11]);
 
   //The 4 words of ciphertext are then written as 16 bytes
   STORE32BE(a, output + 0);
   STORE32BE(b, output + 4);
   STORE32BE(c, output + 8);
   STORE32BE(d, output + 12);
}
 
 
/**
 * @brief Decrypt a 8-byte block using CAST-256 algorithm
 * @param[in] context Pointer to the CAST-256 context
 * @param[in] input Ciphertext block to decrypt
 * @param[out] output Plaintext block resulting from decryption
 **/
 
void cast256DecryptBlock(Cast256Context *context, const uint8_t *input,
   uint8_t *output)
{
   uint32_t a;
   uint32_t b;
   uint32_t c;
   uint32_t d;
 
   //The 16 bytes of ciphertext are split into 4 words
   a = LOAD32BE(input + 0);
   b = LOAD32BE(input + 4);
   c = LOAD32BE(input + 8);
   d = LOAD32BE(input + 12);
 
   //Decryption is identical to encryption except that the sets of quad-round
   //keys Kr and Km derived from K are used in reverse order
   Q(a, b, c, d, context->kr[11], context->km[11]);
   Q(a, b, c, d, context->kr[10], context->km[10]);
   Q(a, b, c, d, context->kr[9], context->km[9]);
   Q(a, b, c, d, context->kr[8], context->km[8]);
   Q(a, b, c, d, context->kr[7], context->km[7]);
   Q(a, b, c, d, context->kr[6], context->km[6]);
 
   QBAR(a, b, c, d, context->kr[5], context->km[5]);
   QBAR(a, b, c, d, context->kr[4], context->km[4]);
   QBAR(a, b, c, d, context->kr[3], context->km[3]);
   QBAR(a, b, c, d, context->kr[2], context->km[2]);
   QBAR(a, b, c, d, context->kr[1], context->km[1]);
   QBAR(a, b, c, d, context->kr[0], context->km[0]);
 
   //The 4 words of plaintext are then written as 16 bytes
   STORE32BE(a, output + 0);
   STORE32BE(b, output + 4);
   STORE32BE(c, output + 8);
   STORE32BE(d, output + 12);
}
 
 
/**
 * @brief Release CAST-256 context
 * @param[in] context Pointer to the CAST-256 context
 **/
 
void cast256Deinit(Cast256Context *context)
{
   //Clear CAST-256 context
   osMemset(context, 0, sizeof(Cast256Context));
}
 
#endif