1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Glue code for POLYVAL using ARMv8 Crypto Extensions
4 *
5 * Copyright (c) 2007 Nokia Siemens Networks - Mikko Herranen <mh1@iki.fi>
6 * Copyright (c) 2009 Intel Corp.
7 * Author: Huang Ying <ying.huang@intel.com>
8 * Copyright 2021 Google LLC
9 */
10
11 /*
12 * Glue code based on ghash-clmulni-intel_glue.c.
13 *
14 * This implementation of POLYVAL uses montgomery multiplication accelerated by
15 * ARMv8 Crypto Extensions instructions to implement the finite field operations.
16 */
17
18 #include <crypto/algapi.h>
19 #include <crypto/internal/hash.h>
20 #include <crypto/internal/simd.h>
21 #include <crypto/polyval.h>
22 #include <linux/crypto.h>
23 #include <linux/init.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/cpufeature.h>
27 #include <asm/neon.h>
28 #include <asm/simd.h>
29
30 #define NUM_KEY_POWERS 8
31
32 struct polyval_tfm_ctx {
33 /*
34 * These powers must be in the order h^8, ..., h^1.
35 */
36 u8 key_powers[NUM_KEY_POWERS][POLYVAL_BLOCK_SIZE];
37 };
38
39 struct polyval_desc_ctx {
40 u8 buffer[POLYVAL_BLOCK_SIZE];
41 u32 bytes;
42 };
43
44 asmlinkage void pmull_polyval_update(const struct polyval_tfm_ctx *keys,
45 const u8 *in, size_t nblocks, u8 *accumulator);
46 asmlinkage void pmull_polyval_mul(u8 *op1, const u8 *op2);
47
48 static void internal_polyval_update(const struct polyval_tfm_ctx *keys,
49 const u8 *in, size_t nblocks, u8 *accumulator)
50 {
51 if (likely(crypto_simd_usable())) {
52 kernel_neon_begin();
53 pmull_polyval_update(keys, in, nblocks, accumulator);
54 kernel_neon_end();
55 } else {
56 polyval_update_non4k(keys->key_powers[NUM_KEY_POWERS-1], in,
57 nblocks, accumulator);
58 }
59 }
60
61 static void internal_polyval_mul(u8 *op1, const u8 *op2)
62 {
63 if (likely(crypto_simd_usable())) {
64 kernel_neon_begin();
65 pmull_polyval_mul(op1, op2);
66 kernel_neon_end();
67 } else {
68 polyval_mul_non4k(op1, op2);
69 }
70 }
71
72 static int polyval_arm64_setkey(struct crypto_shash *tfm,
73 const u8 *key, unsigned int keylen)
74 {
75 struct polyval_tfm_ctx *tctx = crypto_shash_ctx(tfm);
76 int i;
77
78 if (keylen != POLYVAL_BLOCK_SIZE)
79 return -EINVAL;
80
81 memcpy(tctx->key_powers[NUM_KEY_POWERS-1], key, POLYVAL_BLOCK_SIZE);
82
83 for (i = NUM_KEY_POWERS-2; i >= 0; i--) {
84 memcpy(tctx->key_powers[i], key, POLYVAL_BLOCK_SIZE);
85 internal_polyval_mul(tctx->key_powers[i],
86 tctx->key_powers[i+1]);
87 }
88
89 return 0;
90 }
91
92 static int polyval_arm64_init(struct shash_desc *desc)
93 {
94 struct polyval_desc_ctx *dctx = shash_desc_ctx(desc);
95
96 memset(dctx, 0, sizeof(*dctx));
97
98 return 0;
99 }
100
101 static int polyval_arm64_update(struct shash_desc *desc,
102 const u8 *src, unsigned int srclen)
103 {
104 struct polyval_desc_ctx *dctx = shash_desc_ctx(desc);
105 const struct polyval_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
106 u8 *pos;
107 unsigned int nblocks;
108 unsigned int n;
109
110 if (dctx->bytes) {
111 n = min(srclen, dctx->bytes);
112 pos = dctx->buffer + POLYVAL_BLOCK_SIZE - dctx->bytes;
113
114 dctx->bytes -= n;
115 srclen -= n;
116
117 while (n--)
118 *pos++ ^= *src++;
119
120 if (!dctx->bytes)
121 internal_polyval_mul(dctx->buffer,
122 tctx->key_powers[NUM_KEY_POWERS-1]);
123 }
124
125 while (srclen >= POLYVAL_BLOCK_SIZE) {
126 /* allow rescheduling every 4K bytes */
127 nblocks = min(srclen, 4096U) / POLYVAL_BLOCK_SIZE;
128 internal_polyval_update(tctx, src, nblocks, dctx->buffer);
129 srclen -= nblocks * POLYVAL_BLOCK_SIZE;
130 src += nblocks * POLYVAL_BLOCK_SIZE;
131 }
132
133 if (srclen) {
134 dctx->bytes = POLYVAL_BLOCK_SIZE - srclen;
135 pos = dctx->buffer;
136 while (srclen--)
137 *pos++ ^= *src++;
138 }
139
140 return 0;
141 }
142
143 static int polyval_arm64_final(struct shash_desc *desc, u8 *dst)
144 {
145 struct polyval_desc_ctx *dctx = shash_desc_ctx(desc);
146 const struct polyval_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
147
148 if (dctx->bytes) {
149 internal_polyval_mul(dctx->buffer,
150 tctx->key_powers[NUM_KEY_POWERS-1]);
151 }
152
153 memcpy(dst, dctx->buffer, POLYVAL_BLOCK_SIZE);
154
155 return 0;
156 }
157
158 static struct shash_alg polyval_alg = {
159 .digestsize = POLYVAL_DIGEST_SIZE,
160 .init = polyval_arm64_init,
161 .update = polyval_arm64_update,
162 .final = polyval_arm64_final,
163 .setkey = polyval_arm64_setkey,
164 .descsize = sizeof(struct polyval_desc_ctx),
165 .base = {
166 .cra_name = "polyval",
167 .cra_driver_name = "polyval-ce",
168 .cra_priority = 200,
169 .cra_blocksize = POLYVAL_BLOCK_SIZE,
170 .cra_ctxsize = sizeof(struct polyval_tfm_ctx),
171 .cra_module = THIS_MODULE,
172 },
173 };
174
175 static int __init polyval_ce_mod_init(void)
176 {
177 return crypto_register_shash(&polyval_alg);
178 }
179
180 static void __exit polyval_ce_mod_exit(void)
181 {
182 crypto_unregister_shash(&polyval_alg);
183 }
184
185 module_cpu_feature_match(PMULL, polyval_ce_mod_init)
186 module_exit(polyval_ce_mod_exit);
187
188 MODULE_LICENSE("GPL");
189 MODULE_DESCRIPTION("POLYVAL hash function accelerated by ARMv8 Crypto Extensions");
190 MODULE_ALIAS_CRYPTO("polyval");
191 MODULE_ALIAS_CRYPTO("polyval-ce");
192
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.