xref: /openbmc/linux/include/crypto/nhpoly1305.h (revision aac28965)
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