1/*
2 * Cryptographic API.
3 *
4 * SHA-3, as specified in
5 * http://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf
6 *
7 * SHA-3 code by Jeff Garzik <jeff@garzik.org>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)•
12 * any later version.
13 *
14 */
15#include <string.h>
16#include <inttypes.h>
17
18#include "../os/os.h"
19
20#include "sha3.h"
21
22#define KECCAK_ROUNDS 24
23
24#define ROTL64(x, y) (((x) << (y)) | ((x) >> (64 - (y))))
25
26static const uint64_t keccakf_rndc[24] = {
27	0x0000000000000001ULL, 0x0000000000008082ULL, 0x800000000000808aULL,
28	0x8000000080008000ULL, 0x000000000000808bULL, 0x0000000080000001ULL,
29	0x8000000080008081ULL, 0x8000000000008009ULL, 0x000000000000008aULL,
30	0x0000000000000088ULL, 0x0000000080008009ULL, 0x000000008000000aULL,
31	0x000000008000808bULL, 0x800000000000008bULL, 0x8000000000008089ULL,
32	0x8000000000008003ULL, 0x8000000000008002ULL, 0x8000000000000080ULL,
33	0x000000000000800aULL, 0x800000008000000aULL, 0x8000000080008081ULL,
34	0x8000000000008080ULL, 0x0000000080000001ULL, 0x8000000080008008ULL
35};
36
37static const int keccakf_rotc[24] = {
38	1,  3,  6,  10, 15, 21, 28, 36, 45, 55, 2,  14,
39	27, 41, 56, 8,  25, 43, 62, 18, 39, 61, 20, 44
40};
41
42static const int keccakf_piln[24] = {
43	10, 7,  11, 17, 18, 3, 5,  16, 8,  21, 24, 4,
44	15, 23, 19, 13, 12, 2, 20, 14, 22, 9,  6,  1
45};
46
47/* update the state with given number of rounds */
48
49static void keccakf(uint64_t st[25])
50{
51	int i, j, round;
52	uint64_t t, bc[5];
53
54	for (round = 0; round < KECCAK_ROUNDS; round++) {
55
56		/* Theta */
57		for (i = 0; i < 5; i++)
58			bc[i] = st[i] ^ st[i + 5] ^ st[i + 10] ^ st[i + 15]
59				^ st[i + 20];
60
61		for (i = 0; i < 5; i++) {
62			t = bc[(i + 4) % 5] ^ ROTL64(bc[(i + 1) % 5], 1);
63			for (j = 0; j < 25; j += 5)
64				st[j + i] ^= t;
65		}
66
67		/* Rho Pi */
68		t = st[1];
69		for (i = 0; i < 24; i++) {
70			j = keccakf_piln[i];
71			bc[0] = st[j];
72			st[j] = ROTL64(t, keccakf_rotc[i]);
73			t = bc[0];
74		}
75
76		/* Chi */
77		for (j = 0; j < 25; j += 5) {
78			for (i = 0; i < 5; i++)
79				bc[i] = st[j + i];
80			for (i = 0; i < 5; i++)
81				st[j + i] ^= (~bc[(i + 1) % 5]) &
82					     bc[(i + 2) % 5];
83		}
84
85		/* Iota */
86		st[0] ^= keccakf_rndc[round];
87	}
88}
89
90static void fio_sha3_init(struct fio_sha3_ctx *sctx, unsigned int digest_sz)
91{
92	memset(sctx->st, 0, sizeof(sctx->st));
93	sctx->md_len = digest_sz;
94	sctx->rsiz = 200 - 2 * digest_sz;
95	sctx->rsizw = sctx->rsiz / 8;
96	sctx->partial = 0;
97	memset(sctx->buf, 0, sizeof(sctx->buf));
98}
99
100void fio_sha3_224_init(struct fio_sha3_ctx *sctx)
101{
102	fio_sha3_init(sctx, SHA3_224_DIGEST_SIZE);
103}
104
105void fio_sha3_256_init(struct fio_sha3_ctx *sctx)
106{
107	fio_sha3_init(sctx, SHA3_256_DIGEST_SIZE);
108}
109
110void fio_sha3_384_init(struct fio_sha3_ctx *sctx)
111{
112	fio_sha3_init(sctx, SHA3_384_DIGEST_SIZE);
113}
114
115void fio_sha3_512_init(struct fio_sha3_ctx *sctx)
116{
117	fio_sha3_init(sctx, SHA3_512_DIGEST_SIZE);
118}
119
120int fio_sha3_update(struct fio_sha3_ctx *sctx, const uint8_t *data,
121		    unsigned int len)
122{
123	unsigned int done;
124	const uint8_t *src;
125
126	done = 0;
127	src = data;
128
129	if ((sctx->partial + len) > (sctx->rsiz - 1)) {
130		if (sctx->partial) {
131			done = -sctx->partial;
132			memcpy(sctx->buf + sctx->partial, data,
133			       done + sctx->rsiz);
134			src = sctx->buf;
135		}
136
137		do {
138			unsigned int i;
139
140			for (i = 0; i < sctx->rsizw; i++)
141				sctx->st[i] ^= ((uint64_t *) src)[i];
142			keccakf(sctx->st);
143
144			done += sctx->rsiz;
145			src = data + done;
146		} while (done + (sctx->rsiz - 1) < len);
147
148		sctx->partial = 0;
149	}
150	memcpy(sctx->buf + sctx->partial, src, len - done);
151	sctx->partial += (len - done);
152
153	return 0;
154}
155
156void fio_sha3_final(struct fio_sha3_ctx *sctx)
157{
158	unsigned int i, inlen = sctx->partial;
159
160	sctx->buf[inlen++] = 0x06;
161	memset(sctx->buf + inlen, 0, sctx->rsiz - inlen);
162	sctx->buf[sctx->rsiz - 1] |= 0x80;
163
164	for (i = 0; i < sctx->rsizw; i++)
165		sctx->st[i] ^= ((uint64_t *) sctx->buf)[i];
166
167	keccakf(sctx->st);
168
169	for (i = 0; i < sctx->rsizw; i++)
170		sctx->st[i] = cpu_to_le64(sctx->st[i]);
171
172	memcpy(sctx->sha, sctx->st, sctx->md_len);
173}
174