xref: /linux/crypto/vmac.c (revision e9fb13bfec7e017130ddc5c1b5466340470f4900)
1 /*
2  * Modified to interface to the Linux kernel
3  * Copyright (c) 2009, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16  * Place - Suite 330, Boston, MA 02111-1307 USA.
17  */
18 
19 /* --------------------------------------------------------------------------
20  * VMAC and VHASH Implementation by Ted Krovetz (tdk@acm.org) and Wei Dai.
21  * This implementation is herby placed in the public domain.
22  * The authors offers no warranty. Use at your own risk.
23  * Please send bug reports to the authors.
24  * Last modified: 17 APR 08, 1700 PDT
25  * ----------------------------------------------------------------------- */
26 
27 #include <linux/init.h>
28 #include <linux/types.h>
29 #include <linux/crypto.h>
30 #include <linux/scatterlist.h>
31 #include <asm/byteorder.h>
32 #include <crypto/scatterwalk.h>
33 #include <crypto/vmac.h>
34 #include <crypto/internal/hash.h>
35 
36 /*
37  * Constants and masks
38  */
39 #define UINT64_C(x) x##ULL
40 const u64 p64   = UINT64_C(0xfffffffffffffeff);  /* 2^64 - 257 prime  */
41 const u64 m62   = UINT64_C(0x3fffffffffffffff);  /* 62-bit mask       */
42 const u64 m63   = UINT64_C(0x7fffffffffffffff);  /* 63-bit mask       */
43 const u64 m64   = UINT64_C(0xffffffffffffffff);  /* 64-bit mask       */
44 const u64 mpoly = UINT64_C(0x1fffffff1fffffff);  /* Poly key mask     */
45 
46 #define pe64_to_cpup le64_to_cpup		/* Prefer little endian */
47 
48 #ifdef __LITTLE_ENDIAN
49 #define INDEX_HIGH 1
50 #define INDEX_LOW 0
51 #else
52 #define INDEX_HIGH 0
53 #define INDEX_LOW 1
54 #endif
55 
56 /*
57  * The following routines are used in this implementation. They are
58  * written via macros to simulate zero-overhead call-by-reference.
59  *
60  * MUL64: 64x64->128-bit multiplication
61  * PMUL64: assumes top bits cleared on inputs
62  * ADD128: 128x128->128-bit addition
63  */
64 
65 #define ADD128(rh, rl, ih, il)						\
66 	do {								\
67 		u64 _il = (il);						\
68 		(rl) += (_il);						\
69 		if ((rl) < (_il))					\
70 			(rh)++;						\
71 		(rh) += (ih);						\
72 	} while (0)
73 
74 #define MUL32(i1, i2)	((u64)(u32)(i1)*(u32)(i2))
75 
76 #define PMUL64(rh, rl, i1, i2)	/* Assumes m doesn't overflow */	\
77 	do {								\
78 		u64 _i1 = (i1), _i2 = (i2);				\
79 		u64 m = MUL32(_i1, _i2>>32) + MUL32(_i1>>32, _i2);	\
80 		rh = MUL32(_i1>>32, _i2>>32);				\
81 		rl = MUL32(_i1, _i2);					\
82 		ADD128(rh, rl, (m >> 32), (m << 32));			\
83 	} while (0)
84 
85 #define MUL64(rh, rl, i1, i2)						\
86 	do {								\
87 		u64 _i1 = (i1), _i2 = (i2);				\
88 		u64 m1 = MUL32(_i1, _i2>>32);				\
89 		u64 m2 = MUL32(_i1>>32, _i2);				\
90 		rh = MUL32(_i1>>32, _i2>>32);				\
91 		rl = MUL32(_i1, _i2);					\
92 		ADD128(rh, rl, (m1 >> 32), (m1 << 32));			\
93 		ADD128(rh, rl, (m2 >> 32), (m2 << 32));			\
94 	} while (0)
95 
96 /*
97  * For highest performance the L1 NH and L2 polynomial hashes should be
98  * carefully implemented to take advantage of one's target architecture.
99  * Here these two hash functions are defined multiple time; once for
100  * 64-bit architectures, once for 32-bit SSE2 architectures, and once
101  * for the rest (32-bit) architectures.
102  * For each, nh_16 *must* be defined (works on multiples of 16 bytes).
103  * Optionally, nh_vmac_nhbytes can be defined (for multiples of
104  * VMAC_NHBYTES), and nh_16_2 and nh_vmac_nhbytes_2 (versions that do two
105  * NH computations at once).
106  */
107 
108 #ifdef CONFIG_64BIT
109 
110 #define nh_16(mp, kp, nw, rh, rl)					\
111 	do {								\
112 		int i; u64 th, tl;					\
113 		rh = rl = 0;						\
114 		for (i = 0; i < nw; i += 2) {				\
115 			MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i],	\
116 				pe64_to_cpup((mp)+i+1)+(kp)[i+1]);	\
117 			ADD128(rh, rl, th, tl);				\
118 		}							\
119 	} while (0)
120 
121 #define nh_16_2(mp, kp, nw, rh, rl, rh1, rl1)				\
122 	do {								\
123 		int i; u64 th, tl;					\
124 		rh1 = rl1 = rh = rl = 0;				\
125 		for (i = 0; i < nw; i += 2) {				\
126 			MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i],	\
127 				pe64_to_cpup((mp)+i+1)+(kp)[i+1]);	\
128 			ADD128(rh, rl, th, tl);				\
129 			MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i+2],	\
130 				pe64_to_cpup((mp)+i+1)+(kp)[i+3]);	\
131 			ADD128(rh1, rl1, th, tl);			\
132 		}							\
133 	} while (0)
134 
135 #if (VMAC_NHBYTES >= 64) /* These versions do 64-bytes of message at a time */
136 #define nh_vmac_nhbytes(mp, kp, nw, rh, rl)				\
137 	do {								\
138 		int i; u64 th, tl;					\
139 		rh = rl = 0;						\
140 		for (i = 0; i < nw; i += 8) {				\
141 			MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i],	\
142 				pe64_to_cpup((mp)+i+1)+(kp)[i+1]);	\
143 			ADD128(rh, rl, th, tl);				\
144 			MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+2],	\
145 				pe64_to_cpup((mp)+i+3)+(kp)[i+3]);	\
146 			ADD128(rh, rl, th, tl);				\
147 			MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+4],	\
148 				pe64_to_cpup((mp)+i+5)+(kp)[i+5]);	\
149 			ADD128(rh, rl, th, tl);				\
150 			MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+6],	\
151 				pe64_to_cpup((mp)+i+7)+(kp)[i+7]);	\
152 			ADD128(rh, rl, th, tl);				\
153 		}							\
154 	} while (0)
155 
156 #define nh_vmac_nhbytes_2(mp, kp, nw, rh, rl, rh1, rl1)			\
157 	do {								\
158 		int i; u64 th, tl;					\
159 		rh1 = rl1 = rh = rl = 0;				\
160 		for (i = 0; i < nw; i += 8) {				\
161 			MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i],	\
162 				pe64_to_cpup((mp)+i+1)+(kp)[i+1]);	\
163 			ADD128(rh, rl, th, tl);				\
164 			MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i+2],	\
165 				pe64_to_cpup((mp)+i+1)+(kp)[i+3]);	\
166 			ADD128(rh1, rl1, th, tl);			\
167 			MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+2],	\
168 				pe64_to_cpup((mp)+i+3)+(kp)[i+3]);	\
169 			ADD128(rh, rl, th, tl);				\
170 			MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+4],	\
171 				pe64_to_cpup((mp)+i+3)+(kp)[i+5]);	\
172 			ADD128(rh1, rl1, th, tl);			\
173 			MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+4],	\
174 				pe64_to_cpup((mp)+i+5)+(kp)[i+5]);	\
175 			ADD128(rh, rl, th, tl);				\
176 			MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+6],	\
177 				pe64_to_cpup((mp)+i+5)+(kp)[i+7]);	\
178 			ADD128(rh1, rl1, th, tl);			\
179 			MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+6],	\
180 				pe64_to_cpup((mp)+i+7)+(kp)[i+7]);	\
181 			ADD128(rh, rl, th, tl);				\
182 			MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+8],	\
183 				pe64_to_cpup((mp)+i+7)+(kp)[i+9]);	\
184 			ADD128(rh1, rl1, th, tl);			\
185 		}							\
186 	} while (0)
187 #endif
188 
189 #define poly_step(ah, al, kh, kl, mh, ml)				\
190 	do {								\
191 		u64 t1h, t1l, t2h, t2l, t3h, t3l, z = 0;		\
192 		/* compute ab*cd, put bd into result registers */	\
193 		PMUL64(t3h, t3l, al, kh);				\
194 		PMUL64(t2h, t2l, ah, kl);				\
195 		PMUL64(t1h, t1l, ah, 2*kh);				\
196 		PMUL64(ah, al, al, kl);					\
197 		/* add 2 * ac to result */				\
198 		ADD128(ah, al, t1h, t1l);				\
199 		/* add together ad + bc */				\
200 		ADD128(t2h, t2l, t3h, t3l);				\
201 		/* now (ah,al), (t2l,2*t2h) need summing */		\
202 		/* first add the high registers, carrying into t2h */	\
203 		ADD128(t2h, ah, z, t2l);				\
204 		/* double t2h and add top bit of ah */			\
205 		t2h = 2 * t2h + (ah >> 63);				\
206 		ah &= m63;						\
207 		/* now add the low registers */				\
208 		ADD128(ah, al, mh, ml);					\
209 		ADD128(ah, al, z, t2h);					\
210 	} while (0)
211 
212 #else /* ! CONFIG_64BIT */
213 
214 #ifndef nh_16
215 #define nh_16(mp, kp, nw, rh, rl)					\
216 	do {								\
217 		u64 t1, t2, m1, m2, t;					\
218 		int i;							\
219 		rh = rl = t = 0;					\
220 		for (i = 0; i < nw; i += 2)  {				\
221 			t1 = pe64_to_cpup(mp+i) + kp[i];		\
222 			t2 = pe64_to_cpup(mp+i+1) + kp[i+1];		\
223 			m2 = MUL32(t1 >> 32, t2);			\
224 			m1 = MUL32(t1, t2 >> 32);			\
225 			ADD128(rh, rl, MUL32(t1 >> 32, t2 >> 32),	\
226 				MUL32(t1, t2));				\
227 			rh += (u64)(u32)(m1 >> 32)			\
228 				+ (u32)(m2 >> 32);			\
229 			t += (u64)(u32)m1 + (u32)m2;			\
230 		}							\
231 		ADD128(rh, rl, (t >> 32), (t << 32));			\
232 	} while (0)
233 #endif
234 
235 static void poly_step_func(u64 *ahi, u64 *alo,
236 			const u64 *kh, const u64 *kl,
237 			const u64 *mh, const u64 *ml)
238 {
239 #define a0 (*(((u32 *)alo)+INDEX_LOW))
240 #define a1 (*(((u32 *)alo)+INDEX_HIGH))
241 #define a2 (*(((u32 *)ahi)+INDEX_LOW))
242 #define a3 (*(((u32 *)ahi)+INDEX_HIGH))
243 #define k0 (*(((u32 *)kl)+INDEX_LOW))
244 #define k1 (*(((u32 *)kl)+INDEX_HIGH))
245 #define k2 (*(((u32 *)kh)+INDEX_LOW))
246 #define k3 (*(((u32 *)kh)+INDEX_HIGH))
247 
248 	u64 p, q, t;
249 	u32 t2;
250 
251 	p = MUL32(a3, k3);
252 	p += p;
253 	p += *(u64 *)mh;
254 	p += MUL32(a0, k2);
255 	p += MUL32(a1, k1);
256 	p += MUL32(a2, k0);
257 	t = (u32)(p);
258 	p >>= 32;
259 	p += MUL32(a0, k3);
260 	p += MUL32(a1, k2);
261 	p += MUL32(a2, k1);
262 	p += MUL32(a3, k0);
263 	t |= ((u64)((u32)p & 0x7fffffff)) << 32;
264 	p >>= 31;
265 	p += (u64)(((u32 *)ml)[INDEX_LOW]);
266 	p += MUL32(a0, k0);
267 	q =  MUL32(a1, k3);
268 	q += MUL32(a2, k2);
269 	q += MUL32(a3, k1);
270 	q += q;
271 	p += q;
272 	t2 = (u32)(p);
273 	p >>= 32;
274 	p += (u64)(((u32 *)ml)[INDEX_HIGH]);
275 	p += MUL32(a0, k1);
276 	p += MUL32(a1, k0);
277 	q =  MUL32(a2, k3);
278 	q += MUL32(a3, k2);
279 	q += q;
280 	p += q;
281 	*(u64 *)(alo) = (p << 32) | t2;
282 	p >>= 32;
283 	*(u64 *)(ahi) = p + t;
284 
285 #undef a0
286 #undef a1
287 #undef a2
288 #undef a3
289 #undef k0
290 #undef k1
291 #undef k2
292 #undef k3
293 }
294 
295 #define poly_step(ah, al, kh, kl, mh, ml)				\
296 	poly_step_func(&(ah), &(al), &(kh), &(kl), &(mh), &(ml))
297 
298 #endif  /* end of specialized NH and poly definitions */
299 
300 /* At least nh_16 is defined. Defined others as needed here */
301 #ifndef nh_16_2
302 #define nh_16_2(mp, kp, nw, rh, rl, rh2, rl2)				\
303 	do { 								\
304 		nh_16(mp, kp, nw, rh, rl);				\
305 		nh_16(mp, ((kp)+2), nw, rh2, rl2);			\
306 	} while (0)
307 #endif
308 #ifndef nh_vmac_nhbytes
309 #define nh_vmac_nhbytes(mp, kp, nw, rh, rl)				\
310 	nh_16(mp, kp, nw, rh, rl)
311 #endif
312 #ifndef nh_vmac_nhbytes_2
313 #define nh_vmac_nhbytes_2(mp, kp, nw, rh, rl, rh2, rl2)			\
314 	do {								\
315 		nh_vmac_nhbytes(mp, kp, nw, rh, rl);			\
316 		nh_vmac_nhbytes(mp, ((kp)+2), nw, rh2, rl2);		\
317 	} while (0)
318 #endif
319 
320 static void vhash_abort(struct vmac_ctx *ctx)
321 {
322 	ctx->polytmp[0] = ctx->polykey[0] ;
323 	ctx->polytmp[1] = ctx->polykey[1] ;
324 	ctx->first_block_processed = 0;
325 }
326 
327 static u64 l3hash(u64 p1, u64 p2, u64 k1, u64 k2, u64 len)
328 {
329 	u64 rh, rl, t, z = 0;
330 
331 	/* fully reduce (p1,p2)+(len,0) mod p127 */
332 	t = p1 >> 63;
333 	p1 &= m63;
334 	ADD128(p1, p2, len, t);
335 	/* At this point, (p1,p2) is at most 2^127+(len<<64) */
336 	t = (p1 > m63) + ((p1 == m63) && (p2 == m64));
337 	ADD128(p1, p2, z, t);
338 	p1 &= m63;
339 
340 	/* compute (p1,p2)/(2^64-2^32) and (p1,p2)%(2^64-2^32) */
341 	t = p1 + (p2 >> 32);
342 	t += (t >> 32);
343 	t += (u32)t > 0xfffffffeu;
344 	p1 += (t >> 32);
345 	p2 += (p1 << 32);
346 
347 	/* compute (p1+k1)%p64 and (p2+k2)%p64 */
348 	p1 += k1;
349 	p1 += (0 - (p1 < k1)) & 257;
350 	p2 += k2;
351 	p2 += (0 - (p2 < k2)) & 257;
352 
353 	/* compute (p1+k1)*(p2+k2)%p64 */
354 	MUL64(rh, rl, p1, p2);
355 	t = rh >> 56;
356 	ADD128(t, rl, z, rh);
357 	rh <<= 8;
358 	ADD128(t, rl, z, rh);
359 	t += t << 8;
360 	rl += t;
361 	rl += (0 - (rl < t)) & 257;
362 	rl += (0 - (rl > p64-1)) & 257;
363 	return rl;
364 }
365 
366 static void vhash_update(const unsigned char *m,
367 			unsigned int mbytes, /* Pos multiple of VMAC_NHBYTES */
368 			struct vmac_ctx *ctx)
369 {
370 	u64 rh, rl, *mptr;
371 	const u64 *kptr = (u64 *)ctx->nhkey;
372 	int i;
373 	u64 ch, cl;
374 	u64 pkh = ctx->polykey[0];
375 	u64 pkl = ctx->polykey[1];
376 
377 	mptr = (u64 *)m;
378 	i = mbytes / VMAC_NHBYTES;  /* Must be non-zero */
379 
380 	ch = ctx->polytmp[0];
381 	cl = ctx->polytmp[1];
382 
383 	if (!ctx->first_block_processed) {
384 		ctx->first_block_processed = 1;
385 		nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl);
386 		rh &= m62;
387 		ADD128(ch, cl, rh, rl);
388 		mptr += (VMAC_NHBYTES/sizeof(u64));
389 		i--;
390 	}
391 
392 	while (i--) {
393 		nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl);
394 		rh &= m62;
395 		poly_step(ch, cl, pkh, pkl, rh, rl);
396 		mptr += (VMAC_NHBYTES/sizeof(u64));
397 	}
398 
399 	ctx->polytmp[0] = ch;
400 	ctx->polytmp[1] = cl;
401 }
402 
403 static u64 vhash(unsigned char m[], unsigned int mbytes,
404 			u64 *tagl, struct vmac_ctx *ctx)
405 {
406 	u64 rh, rl, *mptr;
407 	const u64 *kptr = (u64 *)ctx->nhkey;
408 	int i, remaining;
409 	u64 ch, cl;
410 	u64 pkh = ctx->polykey[0];
411 	u64 pkl = ctx->polykey[1];
412 
413 	mptr = (u64 *)m;
414 	i = mbytes / VMAC_NHBYTES;
415 	remaining = mbytes % VMAC_NHBYTES;
416 
417 	if (ctx->first_block_processed) {
418 		ch = ctx->polytmp[0];
419 		cl = ctx->polytmp[1];
420 	} else if (i) {
421 		nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, ch, cl);
422 		ch &= m62;
423 		ADD128(ch, cl, pkh, pkl);
424 		mptr += (VMAC_NHBYTES/sizeof(u64));
425 		i--;
426 	} else if (remaining) {
427 		nh_16(mptr, kptr, 2*((remaining+15)/16), ch, cl);
428 		ch &= m62;
429 		ADD128(ch, cl, pkh, pkl);
430 		mptr += (VMAC_NHBYTES/sizeof(u64));
431 		goto do_l3;
432 	} else {/* Empty String */
433 		ch = pkh; cl = pkl;
434 		goto do_l3;
435 	}
436 
437 	while (i--) {
438 		nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl);
439 		rh &= m62;
440 		poly_step(ch, cl, pkh, pkl, rh, rl);
441 		mptr += (VMAC_NHBYTES/sizeof(u64));
442 	}
443 	if (remaining) {
444 		nh_16(mptr, kptr, 2*((remaining+15)/16), rh, rl);
445 		rh &= m62;
446 		poly_step(ch, cl, pkh, pkl, rh, rl);
447 	}
448 
449 do_l3:
450 	vhash_abort(ctx);
451 	remaining *= 8;
452 	return l3hash(ch, cl, ctx->l3key[0], ctx->l3key[1], remaining);
453 }
454 
455 static u64 vmac(unsigned char m[], unsigned int mbytes,
456 			unsigned char n[16], u64 *tagl,
457 			struct vmac_ctx_t *ctx)
458 {
459 	u64 *in_n, *out_p;
460 	u64 p, h;
461 	int i;
462 
463 	in_n = ctx->__vmac_ctx.cached_nonce;
464 	out_p = ctx->__vmac_ctx.cached_aes;
465 
466 	i = n[15] & 1;
467 	if ((*(u64 *)(n+8) != in_n[1]) || (*(u64 *)(n) != in_n[0])) {
468 		in_n[0] = *(u64 *)(n);
469 		in_n[1] = *(u64 *)(n+8);
470 		((unsigned char *)in_n)[15] &= 0xFE;
471 		crypto_cipher_encrypt_one(ctx->child,
472 			(unsigned char *)out_p, (unsigned char *)in_n);
473 
474 		((unsigned char *)in_n)[15] |= (unsigned char)(1-i);
475 	}
476 	p = be64_to_cpup(out_p + i);
477 	h = vhash(m, mbytes, (u64 *)0, &ctx->__vmac_ctx);
478 	return le64_to_cpu(p + h);
479 }
480 
481 static int vmac_set_key(unsigned char user_key[], struct vmac_ctx_t *ctx)
482 {
483 	u64 in[2] = {0}, out[2];
484 	unsigned i;
485 	int err = 0;
486 
487 	err = crypto_cipher_setkey(ctx->child, user_key, VMAC_KEY_LEN);
488 	if (err)
489 		return err;
490 
491 	/* Fill nh key */
492 	((unsigned char *)in)[0] = 0x80;
493 	for (i = 0; i < sizeof(ctx->__vmac_ctx.nhkey)/8; i += 2) {
494 		crypto_cipher_encrypt_one(ctx->child,
495 			(unsigned char *)out, (unsigned char *)in);
496 		ctx->__vmac_ctx.nhkey[i] = be64_to_cpup(out);
497 		ctx->__vmac_ctx.nhkey[i+1] = be64_to_cpup(out+1);
498 		((unsigned char *)in)[15] += 1;
499 	}
500 
501 	/* Fill poly key */
502 	((unsigned char *)in)[0] = 0xC0;
503 	in[1] = 0;
504 	for (i = 0; i < sizeof(ctx->__vmac_ctx.polykey)/8; i += 2) {
505 		crypto_cipher_encrypt_one(ctx->child,
506 			(unsigned char *)out, (unsigned char *)in);
507 		ctx->__vmac_ctx.polytmp[i] =
508 			ctx->__vmac_ctx.polykey[i] =
509 				be64_to_cpup(out) & mpoly;
510 		ctx->__vmac_ctx.polytmp[i+1] =
511 			ctx->__vmac_ctx.polykey[i+1] =
512 				be64_to_cpup(out+1) & mpoly;
513 		((unsigned char *)in)[15] += 1;
514 	}
515 
516 	/* Fill ip key */
517 	((unsigned char *)in)[0] = 0xE0;
518 	in[1] = 0;
519 	for (i = 0; i < sizeof(ctx->__vmac_ctx.l3key)/8; i += 2) {
520 		do {
521 			crypto_cipher_encrypt_one(ctx->child,
522 				(unsigned char *)out, (unsigned char *)in);
523 			ctx->__vmac_ctx.l3key[i] = be64_to_cpup(out);
524 			ctx->__vmac_ctx.l3key[i+1] = be64_to_cpup(out+1);
525 			((unsigned char *)in)[15] += 1;
526 		} while (ctx->__vmac_ctx.l3key[i] >= p64
527 			|| ctx->__vmac_ctx.l3key[i+1] >= p64);
528 	}
529 
530 	/* Invalidate nonce/aes cache and reset other elements */
531 	ctx->__vmac_ctx.cached_nonce[0] = (u64)-1; /* Ensure illegal nonce */
532 	ctx->__vmac_ctx.cached_nonce[1] = (u64)0;  /* Ensure illegal nonce */
533 	ctx->__vmac_ctx.first_block_processed = 0;
534 
535 	return err;
536 }
537 
538 static int vmac_setkey(struct crypto_shash *parent,
539 		const u8 *key, unsigned int keylen)
540 {
541 	struct vmac_ctx_t *ctx = crypto_shash_ctx(parent);
542 
543 	if (keylen != VMAC_KEY_LEN) {
544 		crypto_shash_set_flags(parent, CRYPTO_TFM_RES_BAD_KEY_LEN);
545 		return -EINVAL;
546 	}
547 
548 	return vmac_set_key((u8 *)key, ctx);
549 }
550 
551 static int vmac_init(struct shash_desc *pdesc)
552 {
553 	return 0;
554 }
555 
556 static int vmac_update(struct shash_desc *pdesc, const u8 *p,
557 		unsigned int len)
558 {
559 	struct crypto_shash *parent = pdesc->tfm;
560 	struct vmac_ctx_t *ctx = crypto_shash_ctx(parent);
561 
562 	vhash_update(p, len, &ctx->__vmac_ctx);
563 
564 	return 0;
565 }
566 
567 static int vmac_final(struct shash_desc *pdesc, u8 *out)
568 {
569 	struct crypto_shash *parent = pdesc->tfm;
570 	struct vmac_ctx_t *ctx = crypto_shash_ctx(parent);
571 	vmac_t mac;
572 	u8 nonce[16] = {};
573 
574 	mac = vmac(NULL, 0, nonce, NULL, ctx);
575 	memcpy(out, &mac, sizeof(vmac_t));
576 	memset(&mac, 0, sizeof(vmac_t));
577 	memset(&ctx->__vmac_ctx, 0, sizeof(struct vmac_ctx));
578 	return 0;
579 }
580 
581 static int vmac_init_tfm(struct crypto_tfm *tfm)
582 {
583 	struct crypto_cipher *cipher;
584 	struct crypto_instance *inst = (void *)tfm->__crt_alg;
585 	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
586 	struct vmac_ctx_t *ctx = crypto_tfm_ctx(tfm);
587 
588 	cipher = crypto_spawn_cipher(spawn);
589 	if (IS_ERR(cipher))
590 		return PTR_ERR(cipher);
591 
592 	ctx->child = cipher;
593 	return 0;
594 }
595 
596 static void vmac_exit_tfm(struct crypto_tfm *tfm)
597 {
598 	struct vmac_ctx_t *ctx = crypto_tfm_ctx(tfm);
599 	crypto_free_cipher(ctx->child);
600 }
601 
602 static int vmac_create(struct crypto_template *tmpl, struct rtattr **tb)
603 {
604 	struct shash_instance *inst;
605 	struct crypto_alg *alg;
606 	int err;
607 
608 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
609 	if (err)
610 		return err;
611 
612 	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
613 			CRYPTO_ALG_TYPE_MASK);
614 	if (IS_ERR(alg))
615 		return PTR_ERR(alg);
616 
617 	inst = shash_alloc_instance("vmac", alg);
618 	err = PTR_ERR(inst);
619 	if (IS_ERR(inst))
620 		goto out_put_alg;
621 
622 	err = crypto_init_spawn(shash_instance_ctx(inst), alg,
623 			shash_crypto_instance(inst),
624 			CRYPTO_ALG_TYPE_MASK);
625 	if (err)
626 		goto out_free_inst;
627 
628 	inst->alg.base.cra_priority = alg->cra_priority;
629 	inst->alg.base.cra_blocksize = alg->cra_blocksize;
630 	inst->alg.base.cra_alignmask = alg->cra_alignmask;
631 
632 	inst->alg.digestsize = sizeof(vmac_t);
633 	inst->alg.base.cra_ctxsize = sizeof(struct vmac_ctx_t);
634 	inst->alg.base.cra_init = vmac_init_tfm;
635 	inst->alg.base.cra_exit = vmac_exit_tfm;
636 
637 	inst->alg.init = vmac_init;
638 	inst->alg.update = vmac_update;
639 	inst->alg.final = vmac_final;
640 	inst->alg.setkey = vmac_setkey;
641 
642 	err = shash_register_instance(tmpl, inst);
643 	if (err) {
644 out_free_inst:
645 		shash_free_instance(shash_crypto_instance(inst));
646 	}
647 
648 out_put_alg:
649 	crypto_mod_put(alg);
650 	return err;
651 }
652 
653 static struct crypto_template vmac_tmpl = {
654 	.name = "vmac",
655 	.create = vmac_create,
656 	.free = shash_free_instance,
657 	.module = THIS_MODULE,
658 };
659 
660 static int __init vmac_module_init(void)
661 {
662 	return crypto_register_template(&vmac_tmpl);
663 }
664 
665 static void __exit vmac_module_exit(void)
666 {
667 	crypto_unregister_template(&vmac_tmpl);
668 }
669 
670 module_init(vmac_module_init);
671 module_exit(vmac_module_exit);
672 
673 MODULE_LICENSE("GPL");
674 MODULE_DESCRIPTION("VMAC hash algorithm");
675 
676