1// SPDX-License-Identifier: GPL-2.0
2/*
3 * OpenSSL/Cryptogams accelerated Poly1305 transform for MIPS
4 *
5 * Copyright (C) 2019 Linaro Ltd. <ard.biesheuvel@linaro.org>
6 */
7
8#include <asm/unaligned.h>
9#include <crypto/algapi.h>
10#include <crypto/internal/hash.h>
11#include <crypto/internal/poly1305.h>
12#include <linux/cpufeature.h>
13#include <linux/crypto.h>
14#include <linux/module.h>
15
16asmlinkage void poly1305_init_mips(void *state, const u8 *key);
17asmlinkage void poly1305_blocks_mips(void *state, const u8 *src, u32 len, u32 hibit);
18asmlinkage void poly1305_emit_mips(void *state, u8 *digest, const u32 *nonce);
19
20void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
21{
22	poly1305_init_mips(&dctx->h, key);
23	dctx->s[0] = get_unaligned_le32(key + 16);
24	dctx->s[1] = get_unaligned_le32(key + 20);
25	dctx->s[2] = get_unaligned_le32(key + 24);
26	dctx->s[3] = get_unaligned_le32(key + 28);
27	dctx->buflen = 0;
28}
29EXPORT_SYMBOL(poly1305_init_arch);
30
31static int mips_poly1305_init(struct shash_desc *desc)
32{
33	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
34
35	dctx->buflen = 0;
36	dctx->rset = 0;
37	dctx->sset = false;
38
39	return 0;
40}
41
42static void mips_poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
43				 u32 len, u32 hibit)
44{
45	if (unlikely(!dctx->sset)) {
46		if (!dctx->rset) {
47			poly1305_init_mips(&dctx->h, src);
48			src += POLY1305_BLOCK_SIZE;
49			len -= POLY1305_BLOCK_SIZE;
50			dctx->rset = 1;
51		}
52		if (len >= POLY1305_BLOCK_SIZE) {
53			dctx->s[0] = get_unaligned_le32(src +  0);
54			dctx->s[1] = get_unaligned_le32(src +  4);
55			dctx->s[2] = get_unaligned_le32(src +  8);
56			dctx->s[3] = get_unaligned_le32(src + 12);
57			src += POLY1305_BLOCK_SIZE;
58			len -= POLY1305_BLOCK_SIZE;
59			dctx->sset = true;
60		}
61		if (len < POLY1305_BLOCK_SIZE)
62			return;
63	}
64
65	len &= ~(POLY1305_BLOCK_SIZE - 1);
66
67	poly1305_blocks_mips(&dctx->h, src, len, hibit);
68}
69
70static int mips_poly1305_update(struct shash_desc *desc, const u8 *src,
71				unsigned int len)
72{
73	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
74
75	if (unlikely(dctx->buflen)) {
76		u32 bytes = min(len, POLY1305_BLOCK_SIZE - dctx->buflen);
77
78		memcpy(dctx->buf + dctx->buflen, src, bytes);
79		src += bytes;
80		len -= bytes;
81		dctx->buflen += bytes;
82
83		if (dctx->buflen == POLY1305_BLOCK_SIZE) {
84			mips_poly1305_blocks(dctx, dctx->buf, POLY1305_BLOCK_SIZE, 1);
85			dctx->buflen = 0;
86		}
87	}
88
89	if (likely(len >= POLY1305_BLOCK_SIZE)) {
90		mips_poly1305_blocks(dctx, src, len, 1);
91		src += round_down(len, POLY1305_BLOCK_SIZE);
92		len %= POLY1305_BLOCK_SIZE;
93	}
94
95	if (unlikely(len)) {
96		dctx->buflen = len;
97		memcpy(dctx->buf, src, len);
98	}
99	return 0;
100}
101
102void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src,
103			  unsigned int nbytes)
104{
105	if (unlikely(dctx->buflen)) {
106		u32 bytes = min(nbytes, POLY1305_BLOCK_SIZE - dctx->buflen);
107
108		memcpy(dctx->buf + dctx->buflen, src, bytes);
109		src += bytes;
110		nbytes -= bytes;
111		dctx->buflen += bytes;
112
113		if (dctx->buflen == POLY1305_BLOCK_SIZE) {
114			poly1305_blocks_mips(&dctx->h, dctx->buf,
115					     POLY1305_BLOCK_SIZE, 1);
116			dctx->buflen = 0;
117		}
118	}
119
120	if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
121		unsigned int len = round_down(nbytes, POLY1305_BLOCK_SIZE);
122
123		poly1305_blocks_mips(&dctx->h, src, len, 1);
124		src += len;
125		nbytes %= POLY1305_BLOCK_SIZE;
126	}
127
128	if (unlikely(nbytes)) {
129		dctx->buflen = nbytes;
130		memcpy(dctx->buf, src, nbytes);
131	}
132}
133EXPORT_SYMBOL(poly1305_update_arch);
134
135void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
136{
137	if (unlikely(dctx->buflen)) {
138		dctx->buf[dctx->buflen++] = 1;
139		memset(dctx->buf + dctx->buflen, 0,
140		       POLY1305_BLOCK_SIZE - dctx->buflen);
141		poly1305_blocks_mips(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
142	}
143
144	poly1305_emit_mips(&dctx->h, dst, dctx->s);
145	*dctx = (struct poly1305_desc_ctx){};
146}
147EXPORT_SYMBOL(poly1305_final_arch);
148
149static int mips_poly1305_final(struct shash_desc *desc, u8 *dst)
150{
151	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
152
153	if (unlikely(!dctx->sset))
154		return -ENOKEY;
155
156	poly1305_final_arch(dctx, dst);
157	return 0;
158}
159
160static struct shash_alg mips_poly1305_alg = {
161	.init			= mips_poly1305_init,
162	.update			= mips_poly1305_update,
163	.final			= mips_poly1305_final,
164	.digestsize		= POLY1305_DIGEST_SIZE,
165	.descsize		= sizeof(struct poly1305_desc_ctx),
166
167	.base.cra_name		= "poly1305",
168	.base.cra_driver_name	= "poly1305-mips",
169	.base.cra_priority	= 200,
170	.base.cra_blocksize	= POLY1305_BLOCK_SIZE,
171	.base.cra_module	= THIS_MODULE,
172};
173
174static int __init mips_poly1305_mod_init(void)
175{
176	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
177		crypto_register_shash(&mips_poly1305_alg) : 0;
178}
179
180static void __exit mips_poly1305_mod_exit(void)
181{
182	if (IS_REACHABLE(CONFIG_CRYPTO_HASH))
183		crypto_unregister_shash(&mips_poly1305_alg);
184}
185
186module_init(mips_poly1305_mod_init);
187module_exit(mips_poly1305_mod_exit);
188
189MODULE_LICENSE("GPL v2");
190MODULE_ALIAS_CRYPTO("poly1305");
191MODULE_ALIAS_CRYPTO("poly1305-mips");
192