1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Common values and helper functions for the NHPoly1305 hash function.
4 */
5
6 #ifndef _NHPOLY1305_H
7 #define _NHPOLY1305_H
8
9 #include <crypto/hash.h>
10 #include <crypto/internal/poly1305.h>
11
12 /* NH parameterization: */
13
14 /* Endianness: little */
15 /* Word size: 32 bits (works well on NEON, SSE2, AVX2) */
16
17 /* Stride: 2 words (optimal on ARM32 NEON; works okay on other CPUs too) */
18 #define NH_PAIR_STRIDE 2
19 #define NH_MESSAGE_UNIT (NH_PAIR_STRIDE * 2 * sizeof(u32))
20
21 /* Num passes (Toeplitz iteration count): 4, to give ε = 2^{-128} */
22 #define NH_NUM_PASSES 4
23 #define NH_HASH_BYTES (NH_NUM_PASSES * sizeof(u64))
24
25 /* Max message size: 1024 bytes (32x compression factor) */
26 #define NH_NUM_STRIDES 64
27 #define NH_MESSAGE_WORDS (NH_PAIR_STRIDE * 2 * NH_NUM_STRIDES)
28 #define NH_MESSAGE_BYTES (NH_MESSAGE_WORDS * sizeof(u32))
29 #define NH_KEY_WORDS (NH_MESSAGE_WORDS + \
30 NH_PAIR_STRIDE * 2 * (NH_NUM_PASSES - 1))
31 #define NH_KEY_BYTES (NH_KEY_WORDS * sizeof(u32))
32
33 #define NHPOLY1305_KEY_SIZE (POLY1305_BLOCK_SIZE + NH_KEY_BYTES)
34
35 struct nhpoly1305_key {
36 struct poly1305_core_key poly_key;
37 u32 nh_key[NH_KEY_WORDS];
38 };
39
40 struct nhpoly1305_state {
41
42 /* Running total of polynomial evaluation */
43 struct poly1305_state poly_state;
44
45 /* Partial block buffer */
46 u8 buffer[NH_MESSAGE_UNIT];
47 unsigned int buflen;
48
49 /*
50 * Number of bytes remaining until the current NH message reaches
51 * NH_MESSAGE_BYTES. When nonzero, 'nh_hash' holds the partial NH hash.
52 */
53 unsigned int nh_remaining;
54
55 __le64 nh_hash[NH_NUM_PASSES];
56 };
57
58 typedef void (*nh_t)(const u32 *key, const u8 *message, size_t message_len,
59 __le64 hash[NH_NUM_PASSES]);
60
61 int crypto_nhpoly1305_setkey(struct crypto_shash *tfm,
62 const u8 *key, unsigned int keylen);
63
64 int crypto_nhpoly1305_init(struct shash_desc *desc);
65 int crypto_nhpoly1305_update(struct shash_desc *desc,
66 const u8 *src, unsigned int srclen);
67 int crypto_nhpoly1305_update_helper(struct shash_desc *desc,
68 const u8 *src, unsigned int srclen,
69 nh_t nh_fn);
70 int crypto_nhpoly1305_final(struct shash_desc *desc, u8 *dst);
71 int crypto_nhpoly1305_final_helper(struct shash_desc *desc, u8 *dst,
72 nh_t nh_fn);
73
74 #endif /* _NHPOLY1305_H */
75
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