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