xref: /linux/lib/crypto/sha3.c (revision 0593447248044ab609b43b947d0e198c887ac281)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SHA-3, as specified in
4  * https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.202.pdf
5  *
6  * SHA-3 code by Jeff Garzik <jeff@garzik.org>
7  *               Ard Biesheuvel <ard.biesheuvel@linaro.org>
8  *               David Howells <dhowells@redhat.com>
9  *
10  * See also Documentation/crypto/sha3.rst
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <crypto/sha3.h>
15 #include <crypto/utils.h>
16 #include <linux/export.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/unaligned.h>
20 
21 /*
22  * On some 32-bit architectures, such as h8300, GCC ends up using over 1 KB of
23  * stack if the round calculation gets inlined into the loop in
24  * sha3_keccakf_generic().  On the other hand, on 64-bit architectures with
25  * plenty of [64-bit wide] general purpose registers, not inlining it severely
26  * hurts performance.  So let's use 64-bitness as a heuristic to decide whether
27  * to inline or not.
28  */
29 #ifdef CONFIG_64BIT
30 #define SHA3_INLINE inline
31 #else
32 #define SHA3_INLINE noinline
33 #endif
34 
35 #define SHA3_KECCAK_ROUNDS 24
36 
37 static const u64 sha3_keccakf_rndc[SHA3_KECCAK_ROUNDS] = {
38 	0x0000000000000001ULL, 0x0000000000008082ULL, 0x800000000000808aULL,
39 	0x8000000080008000ULL, 0x000000000000808bULL, 0x0000000080000001ULL,
40 	0x8000000080008081ULL, 0x8000000000008009ULL, 0x000000000000008aULL,
41 	0x0000000000000088ULL, 0x0000000080008009ULL, 0x000000008000000aULL,
42 	0x000000008000808bULL, 0x800000000000008bULL, 0x8000000000008089ULL,
43 	0x8000000000008003ULL, 0x8000000000008002ULL, 0x8000000000000080ULL,
44 	0x000000000000800aULL, 0x800000008000000aULL, 0x8000000080008081ULL,
45 	0x8000000000008080ULL, 0x0000000080000001ULL, 0x8000000080008008ULL
46 };
47 
48 /*
49  * Perform a single round of Keccak mixing.
50  */
51 static SHA3_INLINE void sha3_keccakf_one_round_generic(u64 st[25])
52 {
53 	u64 t[5], tt, bc[5];
54 
55 	/* Theta */
56 	bc[0] = st[0] ^ st[5] ^ st[10] ^ st[15] ^ st[20];
57 	bc[1] = st[1] ^ st[6] ^ st[11] ^ st[16] ^ st[21];
58 	bc[2] = st[2] ^ st[7] ^ st[12] ^ st[17] ^ st[22];
59 	bc[3] = st[3] ^ st[8] ^ st[13] ^ st[18] ^ st[23];
60 	bc[4] = st[4] ^ st[9] ^ st[14] ^ st[19] ^ st[24];
61 
62 	t[0] = bc[4] ^ rol64(bc[1], 1);
63 	t[1] = bc[0] ^ rol64(bc[2], 1);
64 	t[2] = bc[1] ^ rol64(bc[3], 1);
65 	t[3] = bc[2] ^ rol64(bc[4], 1);
66 	t[4] = bc[3] ^ rol64(bc[0], 1);
67 
68 	st[0] ^= t[0];
69 
70 	/* Rho Pi */
71 	tt = st[1];
72 	st[ 1] = rol64(st[ 6] ^ t[1], 44);
73 	st[ 6] = rol64(st[ 9] ^ t[4], 20);
74 	st[ 9] = rol64(st[22] ^ t[2], 61);
75 	st[22] = rol64(st[14] ^ t[4], 39);
76 	st[14] = rol64(st[20] ^ t[0], 18);
77 	st[20] = rol64(st[ 2] ^ t[2], 62);
78 	st[ 2] = rol64(st[12] ^ t[2], 43);
79 	st[12] = rol64(st[13] ^ t[3], 25);
80 	st[13] = rol64(st[19] ^ t[4],  8);
81 	st[19] = rol64(st[23] ^ t[3], 56);
82 	st[23] = rol64(st[15] ^ t[0], 41);
83 	st[15] = rol64(st[ 4] ^ t[4], 27);
84 	st[ 4] = rol64(st[24] ^ t[4], 14);
85 	st[24] = rol64(st[21] ^ t[1],  2);
86 	st[21] = rol64(st[ 8] ^ t[3], 55);
87 	st[ 8] = rol64(st[16] ^ t[1], 45);
88 	st[16] = rol64(st[ 5] ^ t[0], 36);
89 	st[ 5] = rol64(st[ 3] ^ t[3], 28);
90 	st[ 3] = rol64(st[18] ^ t[3], 21);
91 	st[18] = rol64(st[17] ^ t[2], 15);
92 	st[17] = rol64(st[11] ^ t[1], 10);
93 	st[11] = rol64(st[ 7] ^ t[2],  6);
94 	st[ 7] = rol64(st[10] ^ t[0],  3);
95 	st[10] = rol64(    tt ^ t[1],  1);
96 
97 	/* Chi */
98 	bc[ 0] = ~st[ 1] & st[ 2];
99 	bc[ 1] = ~st[ 2] & st[ 3];
100 	bc[ 2] = ~st[ 3] & st[ 4];
101 	bc[ 3] = ~st[ 4] & st[ 0];
102 	bc[ 4] = ~st[ 0] & st[ 1];
103 	st[ 0] ^= bc[ 0];
104 	st[ 1] ^= bc[ 1];
105 	st[ 2] ^= bc[ 2];
106 	st[ 3] ^= bc[ 3];
107 	st[ 4] ^= bc[ 4];
108 
109 	bc[ 0] = ~st[ 6] & st[ 7];
110 	bc[ 1] = ~st[ 7] & st[ 8];
111 	bc[ 2] = ~st[ 8] & st[ 9];
112 	bc[ 3] = ~st[ 9] & st[ 5];
113 	bc[ 4] = ~st[ 5] & st[ 6];
114 	st[ 5] ^= bc[ 0];
115 	st[ 6] ^= bc[ 1];
116 	st[ 7] ^= bc[ 2];
117 	st[ 8] ^= bc[ 3];
118 	st[ 9] ^= bc[ 4];
119 
120 	bc[ 0] = ~st[11] & st[12];
121 	bc[ 1] = ~st[12] & st[13];
122 	bc[ 2] = ~st[13] & st[14];
123 	bc[ 3] = ~st[14] & st[10];
124 	bc[ 4] = ~st[10] & st[11];
125 	st[10] ^= bc[ 0];
126 	st[11] ^= bc[ 1];
127 	st[12] ^= bc[ 2];
128 	st[13] ^= bc[ 3];
129 	st[14] ^= bc[ 4];
130 
131 	bc[ 0] = ~st[16] & st[17];
132 	bc[ 1] = ~st[17] & st[18];
133 	bc[ 2] = ~st[18] & st[19];
134 	bc[ 3] = ~st[19] & st[15];
135 	bc[ 4] = ~st[15] & st[16];
136 	st[15] ^= bc[ 0];
137 	st[16] ^= bc[ 1];
138 	st[17] ^= bc[ 2];
139 	st[18] ^= bc[ 3];
140 	st[19] ^= bc[ 4];
141 
142 	bc[ 0] = ~st[21] & st[22];
143 	bc[ 1] = ~st[22] & st[23];
144 	bc[ 2] = ~st[23] & st[24];
145 	bc[ 3] = ~st[24] & st[20];
146 	bc[ 4] = ~st[20] & st[21];
147 	st[20] ^= bc[ 0];
148 	st[21] ^= bc[ 1];
149 	st[22] ^= bc[ 2];
150 	st[23] ^= bc[ 3];
151 	st[24] ^= bc[ 4];
152 }
153 
154 /* Generic implementation of the Keccak-f[1600] permutation */
155 static void sha3_keccakf_generic(struct sha3_state *state)
156 {
157 	/*
158 	 * Temporarily convert the state words from little-endian to native-
159 	 * endian so that they can be operated on.  Note that on little-endian
160 	 * machines this conversion is a no-op and is optimized out.
161 	 */
162 
163 	for (int i = 0; i < ARRAY_SIZE(state->words); i++)
164 		state->native_words[i] = le64_to_cpu(state->words[i]);
165 
166 	for (int round = 0; round < SHA3_KECCAK_ROUNDS; round++) {
167 		sha3_keccakf_one_round_generic(state->native_words);
168 		/* Iota */
169 		state->native_words[0] ^= sha3_keccakf_rndc[round];
170 	}
171 
172 	for (int i = 0; i < ARRAY_SIZE(state->words); i++)
173 		state->words[i] = cpu_to_le64(state->native_words[i]);
174 }
175 
176 /*
177  * Generic implementation of absorbing the given nonzero number of full blocks
178  * into the sponge function Keccak[r=8*block_size, c=1600-8*block_size].
179  */
180 static void __maybe_unused
181 sha3_absorb_blocks_generic(struct sha3_state *state, const u8 *data,
182 			   size_t nblocks, size_t block_size)
183 {
184 	do {
185 		for (size_t i = 0; i < block_size; i += 8)
186 			state->words[i / 8] ^= get_unaligned((__le64 *)&data[i]);
187 		sha3_keccakf_generic(state);
188 		data += block_size;
189 	} while (--nblocks);
190 }
191 
192 #ifdef CONFIG_CRYPTO_LIB_SHA3_ARCH
193 #include "sha3.h" /* $(SRCARCH)/sha3.h */
194 #else
195 #define sha3_keccakf		sha3_keccakf_generic
196 #define sha3_absorb_blocks	sha3_absorb_blocks_generic
197 #endif
198 
199 void __sha3_update(struct __sha3_ctx *ctx, const u8 *in, size_t in_len)
200 {
201 	const size_t block_size = ctx->block_size;
202 	size_t absorb_offset = ctx->absorb_offset;
203 
204 	/* Warn if squeezing has already begun. */
205 	WARN_ON_ONCE(absorb_offset >= block_size);
206 
207 	if (absorb_offset && absorb_offset + in_len >= block_size) {
208 		crypto_xor(&ctx->state.bytes[absorb_offset], in,
209 			   block_size - absorb_offset);
210 		in += block_size - absorb_offset;
211 		in_len -= block_size - absorb_offset;
212 		sha3_keccakf(&ctx->state);
213 		absorb_offset = 0;
214 	}
215 
216 	if (in_len >= block_size) {
217 		size_t nblocks = in_len / block_size;
218 
219 		sha3_absorb_blocks(&ctx->state, in, nblocks, block_size);
220 		in += nblocks * block_size;
221 		in_len -= nblocks * block_size;
222 	}
223 
224 	if (in_len) {
225 		crypto_xor(&ctx->state.bytes[absorb_offset], in, in_len);
226 		absorb_offset += in_len;
227 	}
228 	ctx->absorb_offset = absorb_offset;
229 }
230 EXPORT_SYMBOL_GPL(__sha3_update);
231 
232 void sha3_final(struct sha3_ctx *sha3_ctx, u8 *out)
233 {
234 	struct __sha3_ctx *ctx = &sha3_ctx->ctx;
235 
236 	ctx->state.bytes[ctx->absorb_offset] ^= 0x06;
237 	ctx->state.bytes[ctx->block_size - 1] ^= 0x80;
238 	sha3_keccakf(&ctx->state);
239 	memcpy(out, ctx->state.bytes, ctx->digest_size);
240 	sha3_zeroize_ctx(sha3_ctx);
241 }
242 EXPORT_SYMBOL_GPL(sha3_final);
243 
244 void shake_squeeze(struct shake_ctx *shake_ctx, u8 *out, size_t out_len)
245 {
246 	struct __sha3_ctx *ctx = &shake_ctx->ctx;
247 	const size_t block_size = ctx->block_size;
248 	size_t squeeze_offset = ctx->squeeze_offset;
249 
250 	if (ctx->absorb_offset < block_size) {
251 		/* First squeeze: */
252 
253 		/* Add the domain separation suffix and padding. */
254 		ctx->state.bytes[ctx->absorb_offset] ^= 0x1f;
255 		ctx->state.bytes[block_size - 1] ^= 0x80;
256 
257 		/* Indicate that squeezing has begun. */
258 		ctx->absorb_offset = block_size;
259 
260 		/*
261 		 * Indicate that no output is pending yet, i.e. sha3_keccakf()
262 		 * will need to be called before the first copy.
263 		 */
264 		squeeze_offset = block_size;
265 	}
266 	while (out_len) {
267 		if (squeeze_offset == block_size) {
268 			sha3_keccakf(&ctx->state);
269 			squeeze_offset = 0;
270 		}
271 		size_t copy = min(out_len, block_size - squeeze_offset);
272 
273 		memcpy(out, &ctx->state.bytes[squeeze_offset], copy);
274 		out += copy;
275 		out_len -= copy;
276 		squeeze_offset += copy;
277 	}
278 	ctx->squeeze_offset = squeeze_offset;
279 }
280 EXPORT_SYMBOL_GPL(shake_squeeze);
281 
282 void sha3_224(const u8 *in, size_t in_len, u8 out[SHA3_224_DIGEST_SIZE])
283 {
284 	struct sha3_ctx ctx;
285 
286 	sha3_224_init(&ctx);
287 	sha3_update(&ctx, in, in_len);
288 	sha3_final(&ctx, out);
289 }
290 EXPORT_SYMBOL_GPL(sha3_224);
291 
292 void sha3_256(const u8 *in, size_t in_len, u8 out[SHA3_256_DIGEST_SIZE])
293 {
294 	struct sha3_ctx ctx;
295 
296 	sha3_256_init(&ctx);
297 	sha3_update(&ctx, in, in_len);
298 	sha3_final(&ctx, out);
299 }
300 EXPORT_SYMBOL_GPL(sha3_256);
301 
302 void sha3_384(const u8 *in, size_t in_len, u8 out[SHA3_384_DIGEST_SIZE])
303 {
304 	struct sha3_ctx ctx;
305 
306 	sha3_384_init(&ctx);
307 	sha3_update(&ctx, in, in_len);
308 	sha3_final(&ctx, out);
309 }
310 EXPORT_SYMBOL_GPL(sha3_384);
311 
312 void sha3_512(const u8 *in, size_t in_len, u8 out[SHA3_512_DIGEST_SIZE])
313 {
314 	struct sha3_ctx ctx;
315 
316 	sha3_512_init(&ctx);
317 	sha3_update(&ctx, in, in_len);
318 	sha3_final(&ctx, out);
319 }
320 EXPORT_SYMBOL_GPL(sha3_512);
321 
322 void shake128(const u8 *in, size_t in_len, u8 *out, size_t out_len)
323 {
324 	struct shake_ctx ctx;
325 
326 	shake128_init(&ctx);
327 	shake_update(&ctx, in, in_len);
328 	shake_squeeze(&ctx, out, out_len);
329 	shake_zeroize_ctx(&ctx);
330 }
331 EXPORT_SYMBOL_GPL(shake128);
332 
333 void shake256(const u8 *in, size_t in_len, u8 *out, size_t out_len)
334 {
335 	struct shake_ctx ctx;
336 
337 	shake256_init(&ctx);
338 	shake_update(&ctx, in, in_len);
339 	shake_squeeze(&ctx, out, out_len);
340 	shake_zeroize_ctx(&ctx);
341 }
342 EXPORT_SYMBOL_GPL(shake256);
343 
344 #ifdef sha3_mod_init_arch
345 static int __init sha3_mod_init(void)
346 {
347 	sha3_mod_init_arch();
348 	return 0;
349 }
350 subsys_initcall(sha3_mod_init);
351 
352 static void __exit sha3_mod_exit(void)
353 {
354 }
355 module_exit(sha3_mod_exit);
356 #endif
357 
358 MODULE_DESCRIPTION("SHA-3 library functions");
359 MODULE_LICENSE("GPL");
360