summaryrefslogtreecommitdiff
path: root/arch/x86/crypto/morus640_glue.c
blob: d8b5fd6cef29ccf57208bc9b018a04660262ead5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * The MORUS-640 Authenticated-Encryption Algorithm
 *   Common x86 SIMD glue skeleton
 *
 * Copyright (c) 2016-2018 Ondrej Mosnacek <omosnacek@gmail.com>
 * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
 */

#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/morus640_glue.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <asm/fpu/api.h>

struct morus640_state {
	struct morus640_block s[MORUS_STATE_BLOCKS];
};

struct morus640_ops {
	int (*skcipher_walk_init)(struct skcipher_walk *walk,
				  struct aead_request *req, bool atomic);

	void (*crypt_blocks)(void *state, const void *src, void *dst,
			     unsigned int length);
	void (*crypt_tail)(void *state, const void *src, void *dst,
			   unsigned int length);
};

static void crypto_morus640_glue_process_ad(
		struct morus640_state *state,
		const struct morus640_glue_ops *ops,
		struct scatterlist *sg_src, unsigned int assoclen)
{
	struct scatter_walk walk;
	struct morus640_block buf;
	unsigned int pos = 0;

	scatterwalk_start(&walk, sg_src);
	while (assoclen != 0) {
		unsigned int size = scatterwalk_clamp(&walk, assoclen);
		unsigned int left = size;
		void *mapped = scatterwalk_map(&walk);
		const u8 *src = (const u8 *)mapped;

		if (pos + size >= MORUS640_BLOCK_SIZE) {
			if (pos > 0) {
				unsigned int fill = MORUS640_BLOCK_SIZE - pos;
				memcpy(buf.bytes + pos, src, fill);
				ops->ad(state, buf.bytes, MORUS640_BLOCK_SIZE);
				pos = 0;
				left -= fill;
				src += fill;
			}

			ops->ad(state, src, left);
			src += left & ~(MORUS640_BLOCK_SIZE - 1);
			left &= MORUS640_BLOCK_SIZE - 1;
		}

		memcpy(buf.bytes + pos, src, left);

		pos += left;
		assoclen -= size;
		scatterwalk_unmap(mapped);
		scatterwalk_advance(&walk, size);
		scatterwalk_done(&walk, 0, assoclen);
	}

	if (pos > 0) {
		memset(buf.bytes + pos, 0, MORUS640_BLOCK_SIZE - pos);
		ops->ad(state, buf.bytes, MORUS640_BLOCK_SIZE);
	}
}

static void crypto_morus640_glue_process_crypt(struct morus640_state *state,
					       struct morus640_ops ops,
					       struct skcipher_walk *walk)
{
	while (walk->nbytes >= MORUS640_BLOCK_SIZE) {
		ops.crypt_blocks(state, walk->src.virt.addr,
				 walk->dst.virt.addr,
				 round_down(walk->nbytes, MORUS640_BLOCK_SIZE));
		skcipher_walk_done(walk, walk->nbytes % MORUS640_BLOCK_SIZE);
	}

	if (walk->nbytes) {
		ops.crypt_tail(state, walk->src.virt.addr, walk->dst.virt.addr,
			       walk->nbytes);
		skcipher_walk_done(walk, 0);
	}
}

int crypto_morus640_glue_setkey(struct crypto_aead *aead, const u8 *key,
				unsigned int keylen)
{
	struct morus640_ctx *ctx = crypto_aead_ctx(aead);

	if (keylen != MORUS640_BLOCK_SIZE) {
		crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}

	memcpy(ctx->key.bytes, key, MORUS640_BLOCK_SIZE);
	return 0;
}
EXPORT_SYMBOL_GPL(crypto_morus640_glue_setkey);

int crypto_morus640_glue_setauthsize(struct crypto_aead *tfm,
				     unsigned int authsize)
{
	return (authsize <= MORUS_MAX_AUTH_SIZE) ? 0 : -EINVAL;
}
EXPORT_SYMBOL_GPL(crypto_morus640_glue_setauthsize);

static void crypto_morus640_glue_crypt(struct aead_request *req,
				       struct morus640_ops ops,
				       unsigned int cryptlen,
				       struct morus640_block *tag_xor)
{
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
	struct morus640_state state;
	struct skcipher_walk walk;

	ops.skcipher_walk_init(&walk, req, true);

	kernel_fpu_begin();

	ctx->ops->init(&state, &ctx->key, req->iv);
	crypto_morus640_glue_process_ad(&state, ctx->ops, req->src, req->assoclen);
	crypto_morus640_glue_process_crypt(&state, ops, &walk);
	ctx->ops->final(&state, tag_xor, req->assoclen, cryptlen);

	kernel_fpu_end();
}

int crypto_morus640_glue_encrypt(struct aead_request *req)
{
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
	struct morus640_ops OPS = {
		.skcipher_walk_init = skcipher_walk_aead_encrypt,
		.crypt_blocks = ctx->ops->enc,
		.crypt_tail = ctx->ops->enc_tail,
	};

	struct morus640_block tag = {};
	unsigned int authsize = crypto_aead_authsize(tfm);
	unsigned int cryptlen = req->cryptlen;

	crypto_morus640_glue_crypt(req, OPS, cryptlen, &tag);

	scatterwalk_map_and_copy(tag.bytes, req->dst,
				 req->assoclen + cryptlen, authsize, 1);
	return 0;
}
EXPORT_SYMBOL_GPL(crypto_morus640_glue_encrypt);

int crypto_morus640_glue_decrypt(struct aead_request *req)
{
	static const u8 zeros[MORUS640_BLOCK_SIZE] = {};

	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
	struct morus640_ops OPS = {
		.skcipher_walk_init = skcipher_walk_aead_decrypt,
		.crypt_blocks = ctx->ops->dec,
		.crypt_tail = ctx->ops->dec_tail,
	};

	struct morus640_block tag;
	unsigned int authsize = crypto_aead_authsize(tfm);
	unsigned int cryptlen = req->cryptlen - authsize;

	scatterwalk_map_and_copy(tag.bytes, req->src,
				 req->assoclen + cryptlen, authsize, 0);

	crypto_morus640_glue_crypt(req, OPS, cryptlen, &tag);

	return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
}
EXPORT_SYMBOL_GPL(crypto_morus640_glue_decrypt);

void crypto_morus640_glue_init_ops(struct crypto_aead *aead,
				   const struct morus640_glue_ops *ops)
{
	struct morus640_ctx *ctx = crypto_aead_ctx(aead);
	ctx->ops = ops;
}
EXPORT_SYMBOL_GPL(crypto_morus640_glue_init_ops);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
MODULE_DESCRIPTION("MORUS-640 AEAD mode -- glue for x86 optimizations");