1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Common values for the Poly1305 algorithm
4 */
5
6 #ifndef _CRYPTO_POLY1305_H
7 #define _CRYPTO_POLY1305_H
8
9 #include <linux/types.h>
10 #include <linux/crypto.h>
11
12 #define POLY1305_BLOCK_SIZE 16
13 #define POLY1305_KEY_SIZE 32
14 #define POLY1305_DIGEST_SIZE 16
15
16 struct poly1305_key {
17 u32 r[5]; /* key, base 2^26 */
18 };
19
20 struct poly1305_state {
21 u32 h[5]; /* accumulator, base 2^26 */
22 };
23
24 struct poly1305_desc_ctx {
25 /* key */
26 struct poly1305_key r;
27 /* finalize key */
28 u32 s[4];
29 /* accumulator */
30 struct poly1305_state h;
31 /* partial buffer */
32 u8 buf[POLY1305_BLOCK_SIZE];
33 /* bytes used in partial buffer */
34 unsigned int buflen;
35 /* r key has been set */
36 bool rset;
37 /* s key has been set */
38 bool sset;
39 };
40
41 /*
42 * Poly1305 core functions. These implement the ε-almost-∆-universal hash
43 * function underlying the Poly1305 MAC, i.e. they don't add an encrypted nonce
44 * ("s key") at the end. They also only support block-aligned inputs.
45 */
46 void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key);
poly1305_core_init(struct poly1305_state * state)47 static inline void poly1305_core_init(struct poly1305_state *state)
48 {
49 memset(state->h, 0, sizeof(state->h));
50 }
51 void poly1305_core_blocks(struct poly1305_state *state,
52 const struct poly1305_key *key,
53 const void *src, unsigned int nblocks);
54 void poly1305_core_emit(const struct poly1305_state *state, void *dst);
55
56 /* Crypto API helper functions for the Poly1305 MAC */
57 int crypto_poly1305_init(struct shash_desc *desc);
58 unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx,
59 const u8 *src, unsigned int srclen);
60 int crypto_poly1305_update(struct shash_desc *desc,
61 const u8 *src, unsigned int srclen);
62 int crypto_poly1305_final(struct shash_desc *desc, u8 *dst);
63
64 #endif
65