1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Glue Code for SSE2 assembler versions of Serpent Cipher
4 *
5 * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
6 *
7 * Glue code based on aesni-intel_glue.c by:
8 *  Copyright (C) 2008, Intel Corp.
9 *    Author: Huang Ying <ying.huang@intel.com>
10 *
11 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
12 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
13 */
14
15#include <linux/module.h>
16#include <linux/types.h>
17#include <linux/crypto.h>
18#include <linux/err.h>
19#include <crypto/algapi.h>
20#include <crypto/b128ops.h>
21#include <crypto/internal/simd.h>
22#include <crypto/serpent.h>
23
24#include "serpent-sse2.h"
25#include "ecb_cbc_helpers.h"
26
27static int serpent_setkey_skcipher(struct crypto_skcipher *tfm,
28				   const u8 *key, unsigned int keylen)
29{
30	return __serpent_setkey(crypto_skcipher_ctx(tfm), key, keylen);
31}
32
33static void serpent_decrypt_cbc_xway(const void *ctx, u8 *dst, const u8 *src)
34{
35	u8 buf[SERPENT_PARALLEL_BLOCKS - 1][SERPENT_BLOCK_SIZE];
36	const u8 *s = src;
37
38	if (dst == src)
39		s = memcpy(buf, src, sizeof(buf));
40	serpent_dec_blk_xway(ctx, dst, src);
41	crypto_xor(dst + SERPENT_BLOCK_SIZE, s, sizeof(buf));
42}
43
44static int ecb_encrypt(struct skcipher_request *req)
45{
46	ECB_WALK_START(req, SERPENT_BLOCK_SIZE, SERPENT_PARALLEL_BLOCKS);
47	ECB_BLOCK(SERPENT_PARALLEL_BLOCKS, serpent_enc_blk_xway);
48	ECB_BLOCK(1, __serpent_encrypt);
49	ECB_WALK_END();
50}
51
52static int ecb_decrypt(struct skcipher_request *req)
53{
54	ECB_WALK_START(req, SERPENT_BLOCK_SIZE, SERPENT_PARALLEL_BLOCKS);
55	ECB_BLOCK(SERPENT_PARALLEL_BLOCKS, serpent_dec_blk_xway);
56	ECB_BLOCK(1, __serpent_decrypt);
57	ECB_WALK_END();
58}
59
60static int cbc_encrypt(struct skcipher_request *req)
61{
62	CBC_WALK_START(req, SERPENT_BLOCK_SIZE, -1);
63	CBC_ENC_BLOCK(__serpent_encrypt);
64	CBC_WALK_END();
65}
66
67static int cbc_decrypt(struct skcipher_request *req)
68{
69	CBC_WALK_START(req, SERPENT_BLOCK_SIZE, SERPENT_PARALLEL_BLOCKS);
70	CBC_DEC_BLOCK(SERPENT_PARALLEL_BLOCKS, serpent_decrypt_cbc_xway);
71	CBC_DEC_BLOCK(1, __serpent_decrypt);
72	CBC_WALK_END();
73}
74
75static struct skcipher_alg serpent_algs[] = {
76	{
77		.base.cra_name		= "__ecb(serpent)",
78		.base.cra_driver_name	= "__ecb-serpent-sse2",
79		.base.cra_priority	= 400,
80		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
81		.base.cra_blocksize	= SERPENT_BLOCK_SIZE,
82		.base.cra_ctxsize	= sizeof(struct serpent_ctx),
83		.base.cra_module	= THIS_MODULE,
84		.min_keysize		= SERPENT_MIN_KEY_SIZE,
85		.max_keysize		= SERPENT_MAX_KEY_SIZE,
86		.setkey			= serpent_setkey_skcipher,
87		.encrypt		= ecb_encrypt,
88		.decrypt		= ecb_decrypt,
89	}, {
90		.base.cra_name		= "__cbc(serpent)",
91		.base.cra_driver_name	= "__cbc-serpent-sse2",
92		.base.cra_priority	= 400,
93		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
94		.base.cra_blocksize	= SERPENT_BLOCK_SIZE,
95		.base.cra_ctxsize	= sizeof(struct serpent_ctx),
96		.base.cra_module	= THIS_MODULE,
97		.min_keysize		= SERPENT_MIN_KEY_SIZE,
98		.max_keysize		= SERPENT_MAX_KEY_SIZE,
99		.ivsize			= SERPENT_BLOCK_SIZE,
100		.setkey			= serpent_setkey_skcipher,
101		.encrypt		= cbc_encrypt,
102		.decrypt		= cbc_decrypt,
103	},
104};
105
106static struct simd_skcipher_alg *serpent_simd_algs[ARRAY_SIZE(serpent_algs)];
107
108static int __init serpent_sse2_init(void)
109{
110	if (!boot_cpu_has(X86_FEATURE_XMM2)) {
111		printk(KERN_INFO "SSE2 instructions are not detected.\n");
112		return -ENODEV;
113	}
114
115	return simd_register_skciphers_compat(serpent_algs,
116					      ARRAY_SIZE(serpent_algs),
117					      serpent_simd_algs);
118}
119
120static void __exit serpent_sse2_exit(void)
121{
122	simd_unregister_skciphers(serpent_algs, ARRAY_SIZE(serpent_algs),
123				  serpent_simd_algs);
124}
125
126module_init(serpent_sse2_init);
127module_exit(serpent_sse2_exit);
128
129MODULE_DESCRIPTION("Serpent Cipher Algorithm, SSE2 optimized");
130MODULE_LICENSE("GPL");
131MODULE_ALIAS_CRYPTO("serpent");
132