aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/src/crypto/zinc/poly1305/poly1305.c
blob: 51bbfb2d10c72813dfad04e7304e0313430cc267 (plain) (blame)
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
/* SPDX-License-Identifier: MIT
 *
 * Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
 *
 * Implementation of the Poly1305 message authenticator.
 *
 * Information: https://cr.yp.to/mac.html
 */

#include <zinc/poly1305.h>

#include <asm/unaligned.h>
#include <linux/kernel.h>
#include <linux/string.h>

#ifndef HAVE_POLY1305_ARCH_IMPLEMENTATION
static inline bool poly1305_init_arch(void *ctx,
				      const u8 key[POLY1305_KEY_SIZE],
				      simd_context_t simd_context)
{
	return false;
}
static inline bool poly1305_blocks_arch(void *ctx, const u8 *input,
					const size_t len, const u32 padbit,
					simd_context_t simd_context)
{
	return false;
}
static inline bool poly1305_emit_arch(void *ctx, u8 mac[POLY1305_MAC_SIZE],
				      const u32 nonce[4],
				      simd_context_t simd_context)
{
	return false;
}
void __init poly1305_fpu_init(void)
{
}
#endif

#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
#include "poly1305-donna64.h"
#else
#include "poly1305-donna32.h"
#endif

void poly1305_init(struct poly1305_ctx *ctx, const u8 key[POLY1305_KEY_SIZE],
		   simd_context_t simd_context)
{
	ctx->nonce[0] = get_unaligned_le32(&key[16]);
	ctx->nonce[1] = get_unaligned_le32(&key[20]);
	ctx->nonce[2] = get_unaligned_le32(&key[24]);
	ctx->nonce[3] = get_unaligned_le32(&key[28]);

	if (!poly1305_init_arch(ctx->opaque, key, simd_context))
		poly1305_init_generic(ctx->opaque, key);

	ctx->num = 0;
}
EXPORT_SYMBOL(poly1305_init);

static inline void poly1305_blocks(void *ctx, const u8 *input, const size_t len,
				   const u32 padbit,
				   simd_context_t simd_context)
{
	if (!poly1305_blocks_arch(ctx, input, len, padbit, simd_context))
		poly1305_blocks_generic(ctx, input, len, padbit);
}

static inline void poly1305_emit(void *ctx, u8 mac[POLY1305_KEY_SIZE],
				 const u32 nonce[4],
				 simd_context_t simd_context)
{
	if (!poly1305_emit_arch(ctx, mac, nonce, simd_context))
		poly1305_emit_generic(ctx, mac, nonce);
}

void poly1305_update(struct poly1305_ctx *ctx, const u8 *input, size_t len,
		     simd_context_t simd_context)
{
	const size_t num = ctx->num % POLY1305_BLOCK_SIZE;
	size_t rem;

	if (num) {
		rem = POLY1305_BLOCK_SIZE - num;
		if (len < rem) {
			memcpy(ctx->data + num, input, len);
			ctx->num = num + len;
			return;
		}
		memcpy(ctx->data + num, input, rem);
		poly1305_blocks(ctx->opaque, ctx->data, POLY1305_BLOCK_SIZE, 1,
				simd_context);
		input += rem;
		len -= rem;
	}

	rem = len % POLY1305_BLOCK_SIZE;
	len -= rem;

	if (len >= POLY1305_BLOCK_SIZE) {
		poly1305_blocks(ctx->opaque, input, len, 1, simd_context);
		input += len;
	}

	if (rem)
		memcpy(ctx->data, input, rem);

	ctx->num = rem;
}
EXPORT_SYMBOL(poly1305_update);

void poly1305_final(struct poly1305_ctx *ctx, u8 mac[POLY1305_MAC_SIZE],
		    simd_context_t simd_context)
{
	size_t num = ctx->num % POLY1305_BLOCK_SIZE;

	if (num) {
		ctx->data[num++] = 1;
		while (num < POLY1305_BLOCK_SIZE)
			ctx->data[num++] = 0;
		poly1305_blocks(ctx->opaque, ctx->data, POLY1305_BLOCK_SIZE, 0,
				simd_context);
	}

	poly1305_emit(ctx->opaque, mac, ctx->nonce, simd_context);

	memzero_explicit(ctx, sizeof(*ctx));
}
EXPORT_SYMBOL(poly1305_final);

#include "../selftest/poly1305.h"