1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Poly1305 authenticator algorithm, RFC7539 |
4 | * |
5 | * Copyright (C) 2015 Martin Willi |
6 | * |
7 | * Based on public domain code by Andrew Moon and Daniel J. Bernstein. |
8 | */ |
9 | |
10 | #include <crypto/internal/poly1305.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> |
13 | #include <asm/unaligned.h> |
14 | |
15 | void poly1305_init_generic(struct poly1305_desc_ctx *desc, |
16 | const u8 key[POLY1305_KEY_SIZE]) |
17 | { |
18 | poly1305_core_setkey(key: &desc->core_r, raw_key: key); |
19 | desc->s[0] = get_unaligned_le32(p: key + 16); |
20 | desc->s[1] = get_unaligned_le32(p: key + 20); |
21 | desc->s[2] = get_unaligned_le32(p: key + 24); |
22 | desc->s[3] = get_unaligned_le32(p: key + 28); |
23 | poly1305_core_init(state: &desc->h); |
24 | desc->buflen = 0; |
25 | desc->sset = true; |
26 | desc->rset = 2; |
27 | } |
28 | EXPORT_SYMBOL_GPL(poly1305_init_generic); |
29 | |
30 | void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src, |
31 | unsigned int nbytes) |
32 | { |
33 | unsigned int bytes; |
34 | |
35 | if (unlikely(desc->buflen)) { |
36 | bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen); |
37 | memcpy(desc->buf + desc->buflen, src, bytes); |
38 | src += bytes; |
39 | nbytes -= bytes; |
40 | desc->buflen += bytes; |
41 | |
42 | if (desc->buflen == POLY1305_BLOCK_SIZE) { |
43 | poly1305_core_blocks(state: &desc->h, key: &desc->core_r, src: desc->buf, |
44 | nblocks: 1, hibit: 1); |
45 | desc->buflen = 0; |
46 | } |
47 | } |
48 | |
49 | if (likely(nbytes >= POLY1305_BLOCK_SIZE)) { |
50 | poly1305_core_blocks(state: &desc->h, key: &desc->core_r, src, |
51 | nblocks: nbytes / POLY1305_BLOCK_SIZE, hibit: 1); |
52 | src += nbytes - (nbytes % POLY1305_BLOCK_SIZE); |
53 | nbytes %= POLY1305_BLOCK_SIZE; |
54 | } |
55 | |
56 | if (unlikely(nbytes)) { |
57 | desc->buflen = nbytes; |
58 | memcpy(desc->buf, src, nbytes); |
59 | } |
60 | } |
61 | EXPORT_SYMBOL_GPL(poly1305_update_generic); |
62 | |
63 | void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst) |
64 | { |
65 | if (unlikely(desc->buflen)) { |
66 | desc->buf[desc->buflen++] = 1; |
67 | memset(desc->buf + desc->buflen, 0, |
68 | POLY1305_BLOCK_SIZE - desc->buflen); |
69 | poly1305_core_blocks(state: &desc->h, key: &desc->core_r, src: desc->buf, nblocks: 1, hibit: 0); |
70 | } |
71 | |
72 | poly1305_core_emit(state: &desc->h, nonce: desc->s, dst); |
73 | *desc = (struct poly1305_desc_ctx){}; |
74 | } |
75 | EXPORT_SYMBOL_GPL(poly1305_final_generic); |
76 | |
77 | MODULE_LICENSE("GPL" ); |
78 | MODULE_AUTHOR("Martin Willi <martin@strongswan.org>" ); |
79 | |