cast256.c File Reference

CAST-256 encryption algorithm. More...

#include "core/crypto.h"
#include "cipher/cast256.h"

Go to the source code of this file.

Macros
#define	TRACE_LEVEL   CRYPTO_TRACE_LEVEL
#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]
#define	F1(y, x, kr, km)
#define	F2(y, x, kr, km)
#define	F3(y, x, kr, km)
#define	Q(a, b, c, d, kr, km)
#define	QBAR(a, b, c, d, kr, km)
#define	W(a, b, c, d, e, f, g, h, tr, tm)

Functions
error_t	cast256Init (Cast256Context *context, const uint8_t *key, size_t keyLen)
	Key expansion. More...
void	cast256EncryptBlock (Cast256Context *context, const uint8_t *input, uint8_t *output)
	Encrypt a 8-byte block using CAST-256 algorithm. More...
void	cast256DecryptBlock (Cast256Context *context, const uint8_t *input, uint8_t *output)
	Decrypt a 8-byte block using CAST-256 algorithm. More...
void	cast256Deinit (Cast256Context *context)
	Release CAST-256 context. More...

Variables
const CipherAlgo	cast256CipherAlgo

Detailed Description

CAST-256 encryption algorithm.

License

SPDX-License-Identifier: GPL-2.0-or-later

Copyright (C) 2010-2025 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

2.5.4

Definition in file cast256.c.

Macro Definition Documentation

F1

#define F1	(		y,
			x,
			kr,
			km
	)

Value:

{ \
   uint32_t t; \
   t = km + x; \
   t = ROL32(t, kr); \
   y ^= ((S1(t, 3) ^ S2(t, 2)) - S3(t, 1)) + S4(t, 0); \
}

Definition at line 48 of file cast256.c.

F2

#define F2	(		y,
			x,
			kr,
			km
	)

Value:

{ \
   uint32_t t; \
   t = km ^ x; \
   t = ROL32(t, kr); \
   y ^= ((S1(t, 3) - S2(t, 2)) + S3(t, 1)) ^ S4(t, 0); \
}

Definition at line 57 of file cast256.c.

F3

#define F3	(		y,
			x,
			kr,
			km
	)

Value:

{ \
   uint32_t t; \
   t = km - x; \
   t = ROL32(t, kr); \
   y ^= ((S1(t, 3) + S2(t, 2)) ^ S3(t, 1)) - S4(t, 0); \
}

Definition at line 66 of file cast256.c.

Q

#define Q	(		a,
			b,
			c,
			d,
			kr,
			km
	)

Value:

{ \
   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]); \
}

Definition at line 75 of file cast256.c.

QBAR

#define QBAR	(		a,
			b,
			c,
			d,
			kr,
			km
	)

Value:

{ \
   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]); \
}

Definition at line 84 of file cast256.c.

S1

#define S1	(		a,
			b
	)		s1[(a >> (8 * b)) & 0xFF]

Definition at line 42 of file cast256.c.

S2

#define S2	(		a,
			b
	)		s2[(a >> (8 * b)) & 0xFF]

Definition at line 43 of file cast256.c.

S3

#define S3	(		a,
			b
	)		s3[(a >> (8 * b)) & 0xFF]

Definition at line 44 of file cast256.c.

S4

#define S4	(		a,
			b
	)		s4[(a >> (8 * b)) & 0xFF]

Definition at line 45 of file cast256.c.

TRACE_LEVEL

#define TRACE_LEVEL   CRYPTO_TRACE_LEVEL

Definition at line 32 of file cast256.c.

W

#define W	(		a,
			b,
			c,
			d,
			e,
			f,
			g,
			h,
			tr,
			tm
	)

Value:

{ \
   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]); \
}

Definition at line 93 of file cast256.c.

Function Documentation

cast256DecryptBlock()

void cast256DecryptBlock	(	Cast256Context *	context,
		const uint8_t *	input,
		uint8_t *	output
	)

Decrypt a 8-byte block using CAST-256 algorithm.

Parameters

[in]	context	Pointer to the CAST-256 context
[in]	input	Ciphertext block to decrypt
[out]	output	Plaintext block resulting from decryption

Definition at line 416 of file cast256.c.

cast256Deinit()

void cast256Deinit

(

Cast256Context *

context

)

Release CAST-256 context.

Parameters

[in]

context

Pointer to the CAST-256 context

Definition at line 459 of file cast256.c.

cast256EncryptBlock()

void cast256EncryptBlock	(	Cast256Context *	context,
		const uint8_t *	input,
		uint8_t *	output
	)

Encrypt a 8-byte block using CAST-256 algorithm.

Parameters

[in]	context	Pointer to the CAST-256 context
[in]	input	Plaintext block to encrypt
[out]	output	Ciphertext block resulting from encryption

Definition at line 372 of file cast256.c.

cast256Init()

error_t cast256Init	(	Cast256Context *	context,
		const uint8_t *	key,
		size_t	keyLen
	)

Key expansion.

Parameters

[in]	context	Pointer to the CAST-256 context to initialize
[in]	key	Pointer to the key
[in]	keyLen	Length of the key

Returns

Error code

Definition at line 315 of file cast256.c.

Variable Documentation

cast256CipherAlgo

const CipherAlgo cast256CipherAlgo

Initial value:

=
{
   "CAST-256",
   sizeof(Cast256Context),
   CIPHER_ALGO_TYPE_BLOCK,
   CAST256_BLOCK_SIZE,
   (CipherAlgoInit) cast256Init,
   NULL,
   NULL,
   (CipherAlgoEncryptBlock) cast256EncryptBlock,
   (CipherAlgoDecryptBlock) cast256DecryptBlock,
   (CipherAlgoDeinit) cast256Deinit
}

Definition at line 292 of file cast256.c.