xref: /linux/lib/crypto/sha512.c (revision 13150742b09e720fdf021de14cd2b98b37415a89)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SHA-384, SHA-512, HMAC-SHA384, and HMAC-SHA512 library functions
4  *
5  * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
6  * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
7  * Copyright (c) 2003 Kyle McMartin <kyle@debian.org>
8  * Copyright 2025 Google LLC
9  */
10 
11 #include <crypto/hmac.h>
12 #include <crypto/sha2.h>
13 #include <linux/export.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/overflow.h>
17 #include <linux/string.h>
18 #include <linux/unaligned.h>
19 #include <linux/wordpart.h>
20 
21 static const struct sha512_block_state sha384_iv = {
22 	.h = {
23 		SHA384_H0, SHA384_H1, SHA384_H2, SHA384_H3,
24 		SHA384_H4, SHA384_H5, SHA384_H6, SHA384_H7,
25 	},
26 };
27 
28 static const struct sha512_block_state sha512_iv = {
29 	.h = {
30 		SHA512_H0, SHA512_H1, SHA512_H2, SHA512_H3,
31 		SHA512_H4, SHA512_H5, SHA512_H6, SHA512_H7,
32 	},
33 };
34 
35 static const u64 sha512_K[80] = {
36 	0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL,
37 	0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
38 	0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL,
39 	0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
40 	0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL,
41 	0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
42 	0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL,
43 	0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
44 	0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL,
45 	0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
46 	0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL,
47 	0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
48 	0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL,
49 	0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
50 	0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL,
51 	0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
52 	0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL,
53 	0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
54 	0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL,
55 	0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
56 	0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL,
57 	0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
58 	0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL,
59 	0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
60 	0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL,
61 	0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
62 	0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL,
63 };
64 
65 #define Ch(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
66 #define Maj(x, y, z) (((x) & (y)) | ((z) & ((x) | (y))))
67 #define e0(x) (ror64((x), 28) ^ ror64((x), 34) ^ ror64((x), 39))
68 #define e1(x) (ror64((x), 14) ^ ror64((x), 18) ^ ror64((x), 41))
69 #define s0(x) (ror64((x), 1) ^ ror64((x), 8) ^ ((x) >> 7))
70 #define s1(x) (ror64((x), 19) ^ ror64((x), 61) ^ ((x) >> 6))
71 
sha512_block_generic(struct sha512_block_state * state,const u8 * data)72 static void sha512_block_generic(struct sha512_block_state *state,
73 				 const u8 *data)
74 {
75 	u64 a = state->h[0];
76 	u64 b = state->h[1];
77 	u64 c = state->h[2];
78 	u64 d = state->h[3];
79 	u64 e = state->h[4];
80 	u64 f = state->h[5];
81 	u64 g = state->h[6];
82 	u64 h = state->h[7];
83 	u64 t1, t2;
84 	u64 W[16];
85 
86 	for (int j = 0; j < 16; j++)
87 		W[j] = get_unaligned_be64(data + j * sizeof(u64));
88 
89 	for (int i = 0; i < 80; i += 8) {
90 		if ((i & 15) == 0 && i != 0) {
91 			for (int j = 0; j < 16; j++) {
92 				W[j & 15] += s1(W[(j - 2) & 15]) +
93 					     W[(j - 7) & 15] +
94 					     s0(W[(j - 15) & 15]);
95 			}
96 		}
97 		t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i]   + W[(i & 15)];
98 		t2 = e0(a) + Maj(a, b, c);    d += t1;    h = t1 + t2;
99 		t1 = g + e1(d) + Ch(d, e, f) + sha512_K[i+1] + W[(i & 15) + 1];
100 		t2 = e0(h) + Maj(h, a, b);    c += t1;    g = t1 + t2;
101 		t1 = f + e1(c) + Ch(c, d, e) + sha512_K[i+2] + W[(i & 15) + 2];
102 		t2 = e0(g) + Maj(g, h, a);    b += t1;    f = t1 + t2;
103 		t1 = e + e1(b) + Ch(b, c, d) + sha512_K[i+3] + W[(i & 15) + 3];
104 		t2 = e0(f) + Maj(f, g, h);    a += t1;    e = t1 + t2;
105 		t1 = d + e1(a) + Ch(a, b, c) + sha512_K[i+4] + W[(i & 15) + 4];
106 		t2 = e0(e) + Maj(e, f, g);    h += t1;    d = t1 + t2;
107 		t1 = c + e1(h) + Ch(h, a, b) + sha512_K[i+5] + W[(i & 15) + 5];
108 		t2 = e0(d) + Maj(d, e, f);    g += t1;    c = t1 + t2;
109 		t1 = b + e1(g) + Ch(g, h, a) + sha512_K[i+6] + W[(i & 15) + 6];
110 		t2 = e0(c) + Maj(c, d, e);    f += t1;    b = t1 + t2;
111 		t1 = a + e1(f) + Ch(f, g, h) + sha512_K[i+7] + W[(i & 15) + 7];
112 		t2 = e0(b) + Maj(b, c, d);    e += t1;    a = t1 + t2;
113 	}
114 
115 	state->h[0] += a;
116 	state->h[1] += b;
117 	state->h[2] += c;
118 	state->h[3] += d;
119 	state->h[4] += e;
120 	state->h[5] += f;
121 	state->h[6] += g;
122 	state->h[7] += h;
123 }
124 
125 static void __maybe_unused
sha512_blocks_generic(struct sha512_block_state * state,const u8 * data,size_t nblocks)126 sha512_blocks_generic(struct sha512_block_state *state,
127 		      const u8 *data, size_t nblocks)
128 {
129 	do {
130 		sha512_block_generic(state, data);
131 		data += SHA512_BLOCK_SIZE;
132 	} while (--nblocks);
133 }
134 
135 #ifdef CONFIG_CRYPTO_LIB_SHA512_ARCH
136 #include "sha512.h" /* $(SRCARCH)/sha512.h */
137 #else
138 #define sha512_blocks sha512_blocks_generic
139 #endif
140 
__sha512_init(struct __sha512_ctx * ctx,const struct sha512_block_state * iv,u64 initial_bytecount)141 static void __sha512_init(struct __sha512_ctx *ctx,
142 			  const struct sha512_block_state *iv,
143 			  u64 initial_bytecount)
144 {
145 	ctx->state = *iv;
146 	ctx->bytecount_lo = initial_bytecount;
147 	ctx->bytecount_hi = 0;
148 }
149 
sha384_init(struct sha384_ctx * ctx)150 void sha384_init(struct sha384_ctx *ctx)
151 {
152 	__sha512_init(&ctx->ctx, &sha384_iv, 0);
153 }
154 EXPORT_SYMBOL_GPL(sha384_init);
155 
sha512_init(struct sha512_ctx * ctx)156 void sha512_init(struct sha512_ctx *ctx)
157 {
158 	__sha512_init(&ctx->ctx, &sha512_iv, 0);
159 }
160 EXPORT_SYMBOL_GPL(sha512_init);
161 
__sha512_update(struct __sha512_ctx * ctx,const u8 * data,size_t len)162 void __sha512_update(struct __sha512_ctx *ctx, const u8 *data, size_t len)
163 {
164 	size_t partial = ctx->bytecount_lo % SHA512_BLOCK_SIZE;
165 
166 	if (check_add_overflow(ctx->bytecount_lo, len, &ctx->bytecount_lo))
167 		ctx->bytecount_hi++;
168 
169 	if (partial + len >= SHA512_BLOCK_SIZE) {
170 		size_t nblocks;
171 
172 		if (partial) {
173 			size_t l = SHA512_BLOCK_SIZE - partial;
174 
175 			memcpy(&ctx->buf[partial], data, l);
176 			data += l;
177 			len -= l;
178 
179 			sha512_blocks(&ctx->state, ctx->buf, 1);
180 		}
181 
182 		nblocks = len / SHA512_BLOCK_SIZE;
183 		len %= SHA512_BLOCK_SIZE;
184 
185 		if (nblocks) {
186 			sha512_blocks(&ctx->state, data, nblocks);
187 			data += nblocks * SHA512_BLOCK_SIZE;
188 		}
189 		partial = 0;
190 	}
191 	if (len)
192 		memcpy(&ctx->buf[partial], data, len);
193 }
194 EXPORT_SYMBOL_GPL(__sha512_update);
195 
__sha512_final(struct __sha512_ctx * ctx,u8 * out,size_t digest_size)196 static void __sha512_final(struct __sha512_ctx *ctx,
197 			   u8 *out, size_t digest_size)
198 {
199 	u64 bitcount_hi = (ctx->bytecount_hi << 3) | (ctx->bytecount_lo >> 61);
200 	u64 bitcount_lo = ctx->bytecount_lo << 3;
201 	size_t partial = ctx->bytecount_lo % SHA512_BLOCK_SIZE;
202 
203 	ctx->buf[partial++] = 0x80;
204 	if (partial > SHA512_BLOCK_SIZE - 16) {
205 		memset(&ctx->buf[partial], 0, SHA512_BLOCK_SIZE - partial);
206 		sha512_blocks(&ctx->state, ctx->buf, 1);
207 		partial = 0;
208 	}
209 	memset(&ctx->buf[partial], 0, SHA512_BLOCK_SIZE - 16 - partial);
210 	*(__be64 *)&ctx->buf[SHA512_BLOCK_SIZE - 16] = cpu_to_be64(bitcount_hi);
211 	*(__be64 *)&ctx->buf[SHA512_BLOCK_SIZE - 8] = cpu_to_be64(bitcount_lo);
212 	sha512_blocks(&ctx->state, ctx->buf, 1);
213 
214 	for (size_t i = 0; i < digest_size; i += 8)
215 		put_unaligned_be64(ctx->state.h[i / 8], out + i);
216 }
217 
sha384_final(struct sha384_ctx * ctx,u8 out[SHA384_DIGEST_SIZE])218 void sha384_final(struct sha384_ctx *ctx, u8 out[SHA384_DIGEST_SIZE])
219 {
220 	__sha512_final(&ctx->ctx, out, SHA384_DIGEST_SIZE);
221 	memzero_explicit(ctx, sizeof(*ctx));
222 }
223 EXPORT_SYMBOL_GPL(sha384_final);
224 
sha512_final(struct sha512_ctx * ctx,u8 out[SHA512_DIGEST_SIZE])225 void sha512_final(struct sha512_ctx *ctx, u8 out[SHA512_DIGEST_SIZE])
226 {
227 	__sha512_final(&ctx->ctx, out, SHA512_DIGEST_SIZE);
228 	memzero_explicit(ctx, sizeof(*ctx));
229 }
230 EXPORT_SYMBOL_GPL(sha512_final);
231 
sha384(const u8 * data,size_t len,u8 out[SHA384_DIGEST_SIZE])232 void sha384(const u8 *data, size_t len, u8 out[SHA384_DIGEST_SIZE])
233 {
234 	struct sha384_ctx ctx;
235 
236 	sha384_init(&ctx);
237 	sha384_update(&ctx, data, len);
238 	sha384_final(&ctx, out);
239 }
240 EXPORT_SYMBOL_GPL(sha384);
241 
sha512(const u8 * data,size_t len,u8 out[SHA512_DIGEST_SIZE])242 void sha512(const u8 *data, size_t len, u8 out[SHA512_DIGEST_SIZE])
243 {
244 	struct sha512_ctx ctx;
245 
246 	sha512_init(&ctx);
247 	sha512_update(&ctx, data, len);
248 	sha512_final(&ctx, out);
249 }
250 EXPORT_SYMBOL_GPL(sha512);
251 
__hmac_sha512_preparekey(struct sha512_block_state * istate,struct sha512_block_state * ostate,const u8 * raw_key,size_t raw_key_len,const struct sha512_block_state * iv)252 static void __hmac_sha512_preparekey(struct sha512_block_state *istate,
253 				     struct sha512_block_state *ostate,
254 				     const u8 *raw_key, size_t raw_key_len,
255 				     const struct sha512_block_state *iv)
256 {
257 	union {
258 		u8 b[SHA512_BLOCK_SIZE];
259 		unsigned long w[SHA512_BLOCK_SIZE / sizeof(unsigned long)];
260 	} derived_key = { 0 };
261 
262 	if (unlikely(raw_key_len > SHA512_BLOCK_SIZE)) {
263 		if (iv == &sha384_iv)
264 			sha384(raw_key, raw_key_len, derived_key.b);
265 		else
266 			sha512(raw_key, raw_key_len, derived_key.b);
267 	} else {
268 		memcpy(derived_key.b, raw_key, raw_key_len);
269 	}
270 
271 	for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)
272 		derived_key.w[i] ^= REPEAT_BYTE(HMAC_IPAD_VALUE);
273 	*istate = *iv;
274 	sha512_blocks(istate, derived_key.b, 1);
275 
276 	for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)
277 		derived_key.w[i] ^= REPEAT_BYTE(HMAC_OPAD_VALUE ^
278 						HMAC_IPAD_VALUE);
279 	*ostate = *iv;
280 	sha512_blocks(ostate, derived_key.b, 1);
281 
282 	memzero_explicit(&derived_key, sizeof(derived_key));
283 }
284 
hmac_sha384_preparekey(struct hmac_sha384_key * key,const u8 * raw_key,size_t raw_key_len)285 void hmac_sha384_preparekey(struct hmac_sha384_key *key,
286 			    const u8 *raw_key, size_t raw_key_len)
287 {
288 	__hmac_sha512_preparekey(&key->key.istate, &key->key.ostate,
289 				 raw_key, raw_key_len, &sha384_iv);
290 }
291 EXPORT_SYMBOL_GPL(hmac_sha384_preparekey);
292 
hmac_sha512_preparekey(struct hmac_sha512_key * key,const u8 * raw_key,size_t raw_key_len)293 void hmac_sha512_preparekey(struct hmac_sha512_key *key,
294 			    const u8 *raw_key, size_t raw_key_len)
295 {
296 	__hmac_sha512_preparekey(&key->key.istate, &key->key.ostate,
297 				 raw_key, raw_key_len, &sha512_iv);
298 }
299 EXPORT_SYMBOL_GPL(hmac_sha512_preparekey);
300 
__hmac_sha512_init(struct __hmac_sha512_ctx * ctx,const struct __hmac_sha512_key * key)301 void __hmac_sha512_init(struct __hmac_sha512_ctx *ctx,
302 			const struct __hmac_sha512_key *key)
303 {
304 	__sha512_init(&ctx->sha_ctx, &key->istate, SHA512_BLOCK_SIZE);
305 	ctx->ostate = key->ostate;
306 }
307 EXPORT_SYMBOL_GPL(__hmac_sha512_init);
308 
hmac_sha384_init_usingrawkey(struct hmac_sha384_ctx * ctx,const u8 * raw_key,size_t raw_key_len)309 void hmac_sha384_init_usingrawkey(struct hmac_sha384_ctx *ctx,
310 				  const u8 *raw_key, size_t raw_key_len)
311 {
312 	__hmac_sha512_preparekey(&ctx->ctx.sha_ctx.state, &ctx->ctx.ostate,
313 				 raw_key, raw_key_len, &sha384_iv);
314 	ctx->ctx.sha_ctx.bytecount_lo = SHA512_BLOCK_SIZE;
315 	ctx->ctx.sha_ctx.bytecount_hi = 0;
316 }
317 EXPORT_SYMBOL_GPL(hmac_sha384_init_usingrawkey);
318 
hmac_sha512_init_usingrawkey(struct hmac_sha512_ctx * ctx,const u8 * raw_key,size_t raw_key_len)319 void hmac_sha512_init_usingrawkey(struct hmac_sha512_ctx *ctx,
320 				  const u8 *raw_key, size_t raw_key_len)
321 {
322 	__hmac_sha512_preparekey(&ctx->ctx.sha_ctx.state, &ctx->ctx.ostate,
323 				 raw_key, raw_key_len, &sha512_iv);
324 	ctx->ctx.sha_ctx.bytecount_lo = SHA512_BLOCK_SIZE;
325 	ctx->ctx.sha_ctx.bytecount_hi = 0;
326 }
327 EXPORT_SYMBOL_GPL(hmac_sha512_init_usingrawkey);
328 
__hmac_sha512_final(struct __hmac_sha512_ctx * ctx,u8 * out,size_t digest_size)329 static void __hmac_sha512_final(struct __hmac_sha512_ctx *ctx,
330 				u8 *out, size_t digest_size)
331 {
332 	/* Generate the padded input for the outer hash in ctx->sha_ctx.buf. */
333 	__sha512_final(&ctx->sha_ctx, ctx->sha_ctx.buf, digest_size);
334 	memset(&ctx->sha_ctx.buf[digest_size], 0,
335 	       SHA512_BLOCK_SIZE - digest_size);
336 	ctx->sha_ctx.buf[digest_size] = 0x80;
337 	*(__be32 *)&ctx->sha_ctx.buf[SHA512_BLOCK_SIZE - 4] =
338 		cpu_to_be32(8 * (SHA512_BLOCK_SIZE + digest_size));
339 
340 	/* Compute the outer hash, which gives the HMAC value. */
341 	sha512_blocks(&ctx->ostate, ctx->sha_ctx.buf, 1);
342 	for (size_t i = 0; i < digest_size; i += 8)
343 		put_unaligned_be64(ctx->ostate.h[i / 8], out + i);
344 
345 	memzero_explicit(ctx, sizeof(*ctx));
346 }
347 
hmac_sha384_final(struct hmac_sha384_ctx * ctx,u8 out[SHA384_DIGEST_SIZE])348 void hmac_sha384_final(struct hmac_sha384_ctx *ctx,
349 		       u8 out[SHA384_DIGEST_SIZE])
350 {
351 	__hmac_sha512_final(&ctx->ctx, out, SHA384_DIGEST_SIZE);
352 }
353 EXPORT_SYMBOL_GPL(hmac_sha384_final);
354 
hmac_sha512_final(struct hmac_sha512_ctx * ctx,u8 out[SHA512_DIGEST_SIZE])355 void hmac_sha512_final(struct hmac_sha512_ctx *ctx,
356 		       u8 out[SHA512_DIGEST_SIZE])
357 {
358 	__hmac_sha512_final(&ctx->ctx, out, SHA512_DIGEST_SIZE);
359 }
360 EXPORT_SYMBOL_GPL(hmac_sha512_final);
361 
hmac_sha384(const struct hmac_sha384_key * key,const u8 * data,size_t data_len,u8 out[SHA384_DIGEST_SIZE])362 void hmac_sha384(const struct hmac_sha384_key *key,
363 		 const u8 *data, size_t data_len, u8 out[SHA384_DIGEST_SIZE])
364 {
365 	struct hmac_sha384_ctx ctx;
366 
367 	hmac_sha384_init(&ctx, key);
368 	hmac_sha384_update(&ctx, data, data_len);
369 	hmac_sha384_final(&ctx, out);
370 }
371 EXPORT_SYMBOL_GPL(hmac_sha384);
372 
hmac_sha512(const struct hmac_sha512_key * key,const u8 * data,size_t data_len,u8 out[SHA512_DIGEST_SIZE])373 void hmac_sha512(const struct hmac_sha512_key *key,
374 		 const u8 *data, size_t data_len, u8 out[SHA512_DIGEST_SIZE])
375 {
376 	struct hmac_sha512_ctx ctx;
377 
378 	hmac_sha512_init(&ctx, key);
379 	hmac_sha512_update(&ctx, data, data_len);
380 	hmac_sha512_final(&ctx, out);
381 }
382 EXPORT_SYMBOL_GPL(hmac_sha512);
383 
hmac_sha384_usingrawkey(const u8 * raw_key,size_t raw_key_len,const u8 * data,size_t data_len,u8 out[SHA384_DIGEST_SIZE])384 void hmac_sha384_usingrawkey(const u8 *raw_key, size_t raw_key_len,
385 			     const u8 *data, size_t data_len,
386 			     u8 out[SHA384_DIGEST_SIZE])
387 {
388 	struct hmac_sha384_ctx ctx;
389 
390 	hmac_sha384_init_usingrawkey(&ctx, raw_key, raw_key_len);
391 	hmac_sha384_update(&ctx, data, data_len);
392 	hmac_sha384_final(&ctx, out);
393 }
394 EXPORT_SYMBOL_GPL(hmac_sha384_usingrawkey);
395 
hmac_sha512_usingrawkey(const u8 * raw_key,size_t raw_key_len,const u8 * data,size_t data_len,u8 out[SHA512_DIGEST_SIZE])396 void hmac_sha512_usingrawkey(const u8 *raw_key, size_t raw_key_len,
397 			     const u8 *data, size_t data_len,
398 			     u8 out[SHA512_DIGEST_SIZE])
399 {
400 	struct hmac_sha512_ctx ctx;
401 
402 	hmac_sha512_init_usingrawkey(&ctx, raw_key, raw_key_len);
403 	hmac_sha512_update(&ctx, data, data_len);
404 	hmac_sha512_final(&ctx, out);
405 }
406 EXPORT_SYMBOL_GPL(hmac_sha512_usingrawkey);
407 
408 #ifdef sha512_mod_init_arch
sha512_mod_init(void)409 static int __init sha512_mod_init(void)
410 {
411 	sha512_mod_init_arch();
412 	return 0;
413 }
414 subsys_initcall(sha512_mod_init);
415 
sha512_mod_exit(void)416 static void __exit sha512_mod_exit(void)
417 {
418 }
419 module_exit(sha512_mod_exit);
420 #endif
421 
422 MODULE_DESCRIPTION("SHA-384, SHA-512, HMAC-SHA384, and HMAC-SHA512 library functions");
423 MODULE_LICENSE("GPL");
424