1 | /* |
---|---|

2 | * VMAC: Message Authentication Code using Universal Hashing |

3 | * |

4 | * Reference: https://tools.ietf.org/html/draft-krovetz-vmac-01 |

5 | * |

6 | * Copyright (c) 2009, Intel Corporation. |

7 | * Copyright (c) 2018, Google Inc. |

8 | * |

9 | * This program is free software; you can redistribute it and/or modify it |

10 | * under the terms and conditions of the GNU General Public License, |

11 | * version 2, as published by the Free Software Foundation. |

12 | * |

13 | * This program is distributed in the hope it will be useful, but WITHOUT |

14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |

15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |

16 | * more details. |

17 | * |

18 | * You should have received a copy of the GNU General Public License along with |

19 | * this program; if not, write to the Free Software Foundation, Inc., 59 Temple |

20 | * Place - Suite 330, Boston, MA 02111-1307 USA. |

21 | */ |

22 | |

23 | /* |

24 | * Derived from: |

25 | * VMAC and VHASH Implementation by Ted Krovetz (tdk@acm.org) and Wei Dai. |

26 | * This implementation is herby placed in the public domain. |

27 | * The authors offers no warranty. Use at your own risk. |

28 | * Last modified: 17 APR 08, 1700 PDT |

29 | */ |

30 | |

31 | #include <asm/unaligned.h> |

32 | #include <linux/init.h> |

33 | #include <linux/types.h> |

34 | #include <linux/crypto.h> |

35 | #include <linux/module.h> |

36 | #include <linux/scatterlist.h> |

37 | #include <asm/byteorder.h> |

38 | #include <crypto/scatterwalk.h> |

39 | #include <crypto/internal/hash.h> |

40 | |

41 | /* |

42 | * User definable settings. |

43 | */ |

44 | #define VMAC_TAG_LEN 64 |

45 | #define VMAC_KEY_SIZE 128/* Must be 128, 192 or 256 */ |

46 | #define VMAC_KEY_LEN (VMAC_KEY_SIZE/8) |

47 | #define VMAC_NHBYTES 128/* Must 2^i for any 3 < i < 13 Standard = 128*/ |

48 | #define VMAC_NONCEBYTES 16 |

49 | |

50 | /* per-transform (per-key) context */ |

51 | struct vmac_tfm_ctx { |

52 | struct crypto_cipher *cipher; |

53 | u64 nhkey[(VMAC_NHBYTES/8)+2*(VMAC_TAG_LEN/64-1)]; |

54 | u64 polykey[2*VMAC_TAG_LEN/64]; |

55 | u64 l3key[2*VMAC_TAG_LEN/64]; |

56 | }; |

57 | |

58 | /* per-request context */ |

59 | struct vmac_desc_ctx { |

60 | union { |

61 | u8 partial[VMAC_NHBYTES]; /* partial block */ |

62 | __le64 partial_words[VMAC_NHBYTES / 8]; |

63 | }; |

64 | unsigned int partial_size; /* size of the partial block */ |

65 | bool first_block_processed; |

66 | u64 polytmp[2*VMAC_TAG_LEN/64]; /* running total of L2-hash */ |

67 | union { |

68 | u8 bytes[VMAC_NONCEBYTES]; |

69 | __be64 pads[VMAC_NONCEBYTES / 8]; |

70 | } nonce; |

71 | unsigned int nonce_size; /* nonce bytes filled so far */ |

72 | }; |

73 | |

74 | /* |

75 | * Constants and masks |

76 | */ |

77 | #define UINT64_C(x) x##ULL |

78 | static const u64 p64 = UINT64_C(0xfffffffffffffeff); /* 2^64 - 257 prime */ |

79 | static const u64 m62 = UINT64_C(0x3fffffffffffffff); /* 62-bit mask */ |

80 | static const u64 m63 = UINT64_C(0x7fffffffffffffff); /* 63-bit mask */ |

81 | static const u64 m64 = UINT64_C(0xffffffffffffffff); /* 64-bit mask */ |

82 | static const u64 mpoly = UINT64_C(0x1fffffff1fffffff); /* Poly key mask */ |

83 | |

84 | #define pe64_to_cpup le64_to_cpup /* Prefer little endian */ |

85 | |

86 | #ifdef __LITTLE_ENDIAN |

87 | #define INDEX_HIGH 1 |

88 | #define INDEX_LOW 0 |

89 | #else |

90 | #define INDEX_HIGH 0 |

91 | #define INDEX_LOW 1 |

92 | #endif |

93 | |

94 | /* |

95 | * The following routines are used in this implementation. They are |

96 | * written via macros to simulate zero-overhead call-by-reference. |

97 | * |

98 | * MUL64: 64x64->128-bit multiplication |

99 | * PMUL64: assumes top bits cleared on inputs |

100 | * ADD128: 128x128->128-bit addition |

101 | */ |

102 | |

103 | #define ADD128(rh, rl, ih, il) \ |

104 | do { \ |

105 | u64 _il = (il); \ |

106 | (rl) += (_il); \ |

107 | if ((rl) < (_il)) \ |

108 | (rh)++; \ |

109 | (rh) += (ih); \ |

110 | } while (0) |

111 | |

112 | #define MUL32(i1, i2) ((u64)(u32)(i1)*(u32)(i2)) |

113 | |

114 | #define PMUL64(rh, rl, i1, i2) /* Assumes m doesn't overflow */ \ |

115 | do { \ |

116 | u64 _i1 = (i1), _i2 = (i2); \ |

117 | u64 m = MUL32(_i1, _i2>>32) + MUL32(_i1>>32, _i2); \ |

118 | rh = MUL32(_i1>>32, _i2>>32); \ |

119 | rl = MUL32(_i1, _i2); \ |

120 | ADD128(rh, rl, (m >> 32), (m << 32)); \ |

121 | } while (0) |

122 | |

123 | #define MUL64(rh, rl, i1, i2) \ |

124 | do { \ |

125 | u64 _i1 = (i1), _i2 = (i2); \ |

126 | u64 m1 = MUL32(_i1, _i2>>32); \ |

127 | u64 m2 = MUL32(_i1>>32, _i2); \ |

128 | rh = MUL32(_i1>>32, _i2>>32); \ |

129 | rl = MUL32(_i1, _i2); \ |

130 | ADD128(rh, rl, (m1 >> 32), (m1 << 32)); \ |

131 | ADD128(rh, rl, (m2 >> 32), (m2 << 32)); \ |

132 | } while (0) |

133 | |

134 | /* |

135 | * For highest performance the L1 NH and L2 polynomial hashes should be |

136 | * carefully implemented to take advantage of one's target architecture. |

137 | * Here these two hash functions are defined multiple time; once for |

138 | * 64-bit architectures, once for 32-bit SSE2 architectures, and once |

139 | * for the rest (32-bit) architectures. |

140 | * For each, nh_16 *must* be defined (works on multiples of 16 bytes). |

141 | * Optionally, nh_vmac_nhbytes can be defined (for multiples of |

142 | * VMAC_NHBYTES), and nh_16_2 and nh_vmac_nhbytes_2 (versions that do two |

143 | * NH computations at once). |

144 | */ |

145 | |

146 | #ifdef CONFIG_64BIT |

147 | |

148 | #define nh_16(mp, kp, nw, rh, rl) \ |

149 | do { \ |

150 | int i; u64 th, tl; \ |

151 | rh = rl = 0; \ |

152 | for (i = 0; i < nw; i += 2) { \ |

153 | MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i], \ |

154 | pe64_to_cpup((mp)+i+1)+(kp)[i+1]); \ |

155 | ADD128(rh, rl, th, tl); \ |

156 | } \ |

157 | } while (0) |

158 | |

159 | #define nh_16_2(mp, kp, nw, rh, rl, rh1, rl1) \ |

160 | do { \ |

161 | int i; u64 th, tl; \ |

162 | rh1 = rl1 = rh = rl = 0; \ |

163 | for (i = 0; i < nw; i += 2) { \ |

164 | MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i], \ |

165 | pe64_to_cpup((mp)+i+1)+(kp)[i+1]); \ |

166 | ADD128(rh, rl, th, tl); \ |

167 | MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i+2], \ |

168 | pe64_to_cpup((mp)+i+1)+(kp)[i+3]); \ |

169 | ADD128(rh1, rl1, th, tl); \ |

170 | } \ |

171 | } while (0) |

172 | |

173 | #if (VMAC_NHBYTES >= 64) /* These versions do 64-bytes of message at a time */ |

174 | #define nh_vmac_nhbytes(mp, kp, nw, rh, rl) \ |

175 | do { \ |

176 | int i; u64 th, tl; \ |

177 | rh = rl = 0; \ |

178 | for (i = 0; i < nw; i += 8) { \ |

179 | MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i], \ |

180 | pe64_to_cpup((mp)+i+1)+(kp)[i+1]); \ |

181 | ADD128(rh, rl, th, tl); \ |

182 | MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+2], \ |

183 | pe64_to_cpup((mp)+i+3)+(kp)[i+3]); \ |

184 | ADD128(rh, rl, th, tl); \ |

185 | MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+4], \ |

186 | pe64_to_cpup((mp)+i+5)+(kp)[i+5]); \ |

187 | ADD128(rh, rl, th, tl); \ |

188 | MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+6], \ |

189 | pe64_to_cpup((mp)+i+7)+(kp)[i+7]); \ |

190 | ADD128(rh, rl, th, tl); \ |

191 | } \ |

192 | } while (0) |

193 | |

194 | #define nh_vmac_nhbytes_2(mp, kp, nw, rh, rl, rh1, rl1) \ |

195 | do { \ |

196 | int i; u64 th, tl; \ |

197 | rh1 = rl1 = rh = rl = 0; \ |

198 | for (i = 0; i < nw; i += 8) { \ |

199 | MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i], \ |

200 | pe64_to_cpup((mp)+i+1)+(kp)[i+1]); \ |

201 | ADD128(rh, rl, th, tl); \ |

202 | MUL64(th, tl, pe64_to_cpup((mp)+i)+(kp)[i+2], \ |

203 | pe64_to_cpup((mp)+i+1)+(kp)[i+3]); \ |

204 | ADD128(rh1, rl1, th, tl); \ |

205 | MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+2], \ |

206 | pe64_to_cpup((mp)+i+3)+(kp)[i+3]); \ |

207 | ADD128(rh, rl, th, tl); \ |

208 | MUL64(th, tl, pe64_to_cpup((mp)+i+2)+(kp)[i+4], \ |

209 | pe64_to_cpup((mp)+i+3)+(kp)[i+5]); \ |

210 | ADD128(rh1, rl1, th, tl); \ |

211 | MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+4], \ |

212 | pe64_to_cpup((mp)+i+5)+(kp)[i+5]); \ |

213 | ADD128(rh, rl, th, tl); \ |

214 | MUL64(th, tl, pe64_to_cpup((mp)+i+4)+(kp)[i+6], \ |

215 | pe64_to_cpup((mp)+i+5)+(kp)[i+7]); \ |

216 | ADD128(rh1, rl1, th, tl); \ |

217 | MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+6], \ |

218 | pe64_to_cpup((mp)+i+7)+(kp)[i+7]); \ |

219 | ADD128(rh, rl, th, tl); \ |

220 | MUL64(th, tl, pe64_to_cpup((mp)+i+6)+(kp)[i+8], \ |

221 | pe64_to_cpup((mp)+i+7)+(kp)[i+9]); \ |

222 | ADD128(rh1, rl1, th, tl); \ |

223 | } \ |

224 | } while (0) |

225 | #endif |

226 | |

227 | #define poly_step(ah, al, kh, kl, mh, ml) \ |

228 | do { \ |

229 | u64 t1h, t1l, t2h, t2l, t3h, t3l, z = 0; \ |

230 | /* compute ab*cd, put bd into result registers */ \ |

231 | PMUL64(t3h, t3l, al, kh); \ |

232 | PMUL64(t2h, t2l, ah, kl); \ |

233 | PMUL64(t1h, t1l, ah, 2*kh); \ |

234 | PMUL64(ah, al, al, kl); \ |

235 | /* add 2 * ac to result */ \ |

236 | ADD128(ah, al, t1h, t1l); \ |

237 | /* add together ad + bc */ \ |

238 | ADD128(t2h, t2l, t3h, t3l); \ |

239 | /* now (ah,al), (t2l,2*t2h) need summing */ \ |

240 | /* first add the high registers, carrying into t2h */ \ |

241 | ADD128(t2h, ah, z, t2l); \ |

242 | /* double t2h and add top bit of ah */ \ |

243 | t2h = 2 * t2h + (ah >> 63); \ |

244 | ah &= m63; \ |

245 | /* now add the low registers */ \ |

246 | ADD128(ah, al, mh, ml); \ |

247 | ADD128(ah, al, z, t2h); \ |

248 | } while (0) |

249 | |

250 | #else /* ! CONFIG_64BIT */ |

251 | |

252 | #ifndef nh_16 |

253 | #define nh_16(mp, kp, nw, rh, rl) \ |

254 | do { \ |

255 | u64 t1, t2, m1, m2, t; \ |

256 | int i; \ |

257 | rh = rl = t = 0; \ |

258 | for (i = 0; i < nw; i += 2) { \ |

259 | t1 = pe64_to_cpup(mp+i) + kp[i]; \ |

260 | t2 = pe64_to_cpup(mp+i+1) + kp[i+1]; \ |

261 | m2 = MUL32(t1 >> 32, t2); \ |

262 | m1 = MUL32(t1, t2 >> 32); \ |

263 | ADD128(rh, rl, MUL32(t1 >> 32, t2 >> 32), \ |

264 | MUL32(t1, t2)); \ |

265 | rh += (u64)(u32)(m1 >> 32) \ |

266 | + (u32)(m2 >> 32); \ |

267 | t += (u64)(u32)m1 + (u32)m2; \ |

268 | } \ |

269 | ADD128(rh, rl, (t >> 32), (t << 32)); \ |

270 | } while (0) |

271 | #endif |

272 | |

273 | static void poly_step_func(u64 *ahi, u64 *alo, |

274 | const u64 *kh, const u64 *kl, |

275 | const u64 *mh, const u64 *ml) |

276 | { |

277 | #define a0 (*(((u32 *)alo)+INDEX_LOW)) |

278 | #define a1 (*(((u32 *)alo)+INDEX_HIGH)) |

279 | #define a2 (*(((u32 *)ahi)+INDEX_LOW)) |

280 | #define a3 (*(((u32 *)ahi)+INDEX_HIGH)) |

281 | #define k0 (*(((u32 *)kl)+INDEX_LOW)) |

282 | #define k1 (*(((u32 *)kl)+INDEX_HIGH)) |

283 | #define k2 (*(((u32 *)kh)+INDEX_LOW)) |

284 | #define k3 (*(((u32 *)kh)+INDEX_HIGH)) |

285 | |

286 | u64 p, q, t; |

287 | u32 t2; |

288 | |

289 | p = MUL32(a3, k3); |

290 | p += p; |

291 | p += *(u64 *)mh; |

292 | p += MUL32(a0, k2); |

293 | p += MUL32(a1, k1); |

294 | p += MUL32(a2, k0); |

295 | t = (u32)(p); |

296 | p >>= 32; |

297 | p += MUL32(a0, k3); |

298 | p += MUL32(a1, k2); |

299 | p += MUL32(a2, k1); |

300 | p += MUL32(a3, k0); |

301 | t |= ((u64)((u32)p & 0x7fffffff)) << 32; |

302 | p >>= 31; |

303 | p += (u64)(((u32 *)ml)[INDEX_LOW]); |

304 | p += MUL32(a0, k0); |

305 | q = MUL32(a1, k3); |

306 | q += MUL32(a2, k2); |

307 | q += MUL32(a3, k1); |

308 | q += q; |

309 | p += q; |

310 | t2 = (u32)(p); |

311 | p >>= 32; |

312 | p += (u64)(((u32 *)ml)[INDEX_HIGH]); |

313 | p += MUL32(a0, k1); |

314 | p += MUL32(a1, k0); |

315 | q = MUL32(a2, k3); |

316 | q += MUL32(a3, k2); |

317 | q += q; |

318 | p += q; |

319 | *(u64 *)(alo) = (p << 32) | t2; |

320 | p >>= 32; |

321 | *(u64 *)(ahi) = p + t; |

322 | |

323 | #undef a0 |

324 | #undef a1 |

325 | #undef a2 |

326 | #undef a3 |

327 | #undef k0 |

328 | #undef k1 |

329 | #undef k2 |

330 | #undef k3 |

331 | } |

332 | |

333 | #define poly_step(ah, al, kh, kl, mh, ml) \ |

334 | poly_step_func(&(ah), &(al), &(kh), &(kl), &(mh), &(ml)) |

335 | |

336 | #endif /* end of specialized NH and poly definitions */ |

337 | |

338 | /* At least nh_16 is defined. Defined others as needed here */ |

339 | #ifndef nh_16_2 |

340 | #define nh_16_2(mp, kp, nw, rh, rl, rh2, rl2) \ |

341 | do { \ |

342 | nh_16(mp, kp, nw, rh, rl); \ |

343 | nh_16(mp, ((kp)+2), nw, rh2, rl2); \ |

344 | } while (0) |

345 | #endif |

346 | #ifndef nh_vmac_nhbytes |

347 | #define nh_vmac_nhbytes(mp, kp, nw, rh, rl) \ |

348 | nh_16(mp, kp, nw, rh, rl) |

349 | #endif |

350 | #ifndef nh_vmac_nhbytes_2 |

351 | #define nh_vmac_nhbytes_2(mp, kp, nw, rh, rl, rh2, rl2) \ |

352 | do { \ |

353 | nh_vmac_nhbytes(mp, kp, nw, rh, rl); \ |

354 | nh_vmac_nhbytes(mp, ((kp)+2), nw, rh2, rl2); \ |

355 | } while (0) |

356 | #endif |

357 | |

358 | static u64 l3hash(u64 p1, u64 p2, u64 k1, u64 k2, u64 len) |

359 | { |

360 | u64 rh, rl, t, z = 0; |

361 | |

362 | /* fully reduce (p1,p2)+(len,0) mod p127 */ |

363 | t = p1 >> 63; |

364 | p1 &= m63; |

365 | ADD128(p1, p2, len, t); |

366 | /* At this point, (p1,p2) is at most 2^127+(len<<64) */ |

367 | t = (p1 > m63) + ((p1 == m63) && (p2 == m64)); |

368 | ADD128(p1, p2, z, t); |

369 | p1 &= m63; |

370 | |

371 | /* compute (p1,p2)/(2^64-2^32) and (p1,p2)%(2^64-2^32) */ |

372 | t = p1 + (p2 >> 32); |

373 | t += (t >> 32); |

374 | t += (u32)t > 0xfffffffeu; |

375 | p1 += (t >> 32); |

376 | p2 += (p1 << 32); |

377 | |

378 | /* compute (p1+k1)%p64 and (p2+k2)%p64 */ |

379 | p1 += k1; |

380 | p1 += (0 - (p1 < k1)) & 257; |

381 | p2 += k2; |

382 | p2 += (0 - (p2 < k2)) & 257; |

383 | |

384 | /* compute (p1+k1)*(p2+k2)%p64 */ |

385 | MUL64(rh, rl, p1, p2); |

386 | t = rh >> 56; |

387 | ADD128(t, rl, z, rh); |

388 | rh <<= 8; |

389 | ADD128(t, rl, z, rh); |

390 | t += t << 8; |

391 | rl += t; |

392 | rl += (0 - (rl < t)) & 257; |

393 | rl += (0 - (rl > p64-1)) & 257; |

394 | return rl; |

395 | } |

396 | |

397 | /* L1 and L2-hash one or more VMAC_NHBYTES-byte blocks */ |

398 | static void vhash_blocks(const struct vmac_tfm_ctx *tctx, |

399 | struct vmac_desc_ctx *dctx, |

400 | const __le64 *mptr, unsigned int blocks) |

401 | { |

402 | const u64 *kptr = tctx->nhkey; |

403 | const u64 pkh = tctx->polykey[0]; |

404 | const u64 pkl = tctx->polykey[1]; |

405 | u64 ch = dctx->polytmp[0]; |

406 | u64 cl = dctx->polytmp[1]; |

407 | u64 rh, rl; |

408 | |

409 | if (!dctx->first_block_processed) { |

410 | dctx->first_block_processed = true; |

411 | nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl); |

412 | rh &= m62; |

413 | ADD128(ch, cl, rh, rl); |

414 | mptr += (VMAC_NHBYTES/sizeof(u64)); |

415 | blocks--; |

416 | } |

417 | |

418 | while (blocks--) { |

419 | nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl); |

420 | rh &= m62; |

421 | poly_step(ch, cl, pkh, pkl, rh, rl); |

422 | mptr += (VMAC_NHBYTES/sizeof(u64)); |

423 | } |

424 | |

425 | dctx->polytmp[0] = ch; |

426 | dctx->polytmp[1] = cl; |

427 | } |

428 | |

429 | static int vmac_setkey(struct crypto_shash *tfm, |

430 | const u8 *key, unsigned int keylen) |

431 | { |

432 | struct vmac_tfm_ctx *tctx = crypto_shash_ctx(tfm); |

433 | __be64 out[2]; |

434 | u8 in[16] = { 0 }; |

435 | unsigned int i; |

436 | int err; |

437 | |

438 | if (keylen != VMAC_KEY_LEN) { |

439 | crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); |

440 | return -EINVAL; |

441 | } |

442 | |

443 | err = crypto_cipher_setkey(tctx->cipher, key, keylen); |

444 | if (err) |

445 | return err; |

446 | |

447 | /* Fill nh key */ |

448 | in[0] = 0x80; |

449 | for (i = 0; i < ARRAY_SIZE(tctx->nhkey); i += 2) { |

450 | crypto_cipher_encrypt_one(tctx->cipher, (u8 *)out, in); |

451 | tctx->nhkey[i] = be64_to_cpu(out[0]); |

452 | tctx->nhkey[i+1] = be64_to_cpu(out[1]); |

453 | in[15]++; |

454 | } |

455 | |

456 | /* Fill poly key */ |

457 | in[0] = 0xC0; |

458 | in[15] = 0; |

459 | for (i = 0; i < ARRAY_SIZE(tctx->polykey); i += 2) { |

460 | crypto_cipher_encrypt_one(tctx->cipher, (u8 *)out, in); |

461 | tctx->polykey[i] = be64_to_cpu(out[0]) & mpoly; |

462 | tctx->polykey[i+1] = be64_to_cpu(out[1]) & mpoly; |

463 | in[15]++; |

464 | } |

465 | |

466 | /* Fill ip key */ |

467 | in[0] = 0xE0; |

468 | in[15] = 0; |

469 | for (i = 0; i < ARRAY_SIZE(tctx->l3key); i += 2) { |

470 | do { |

471 | crypto_cipher_encrypt_one(tctx->cipher, (u8 *)out, in); |

472 | tctx->l3key[i] = be64_to_cpu(out[0]); |

473 | tctx->l3key[i+1] = be64_to_cpu(out[1]); |

474 | in[15]++; |

475 | } while (tctx->l3key[i] >= p64 || tctx->l3key[i+1] >= p64); |

476 | } |

477 | |

478 | return 0; |

479 | } |

480 | |

481 | static int vmac_init(struct shash_desc *desc) |

482 | { |

483 | const struct vmac_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm); |

484 | struct vmac_desc_ctx *dctx = shash_desc_ctx(desc); |

485 | |

486 | dctx->partial_size = 0; |

487 | dctx->first_block_processed = false; |

488 | memcpy(dctx->polytmp, tctx->polykey, sizeof(dctx->polytmp)); |

489 | dctx->nonce_size = 0; |

490 | return 0; |

491 | } |

492 | |

493 | static int vmac_update(struct shash_desc *desc, const u8 *p, unsigned int len) |

494 | { |

495 | const struct vmac_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm); |

496 | struct vmac_desc_ctx *dctx = shash_desc_ctx(desc); |

497 | unsigned int n; |

498 | |

499 | /* Nonce is passed as first VMAC_NONCEBYTES bytes of data */ |

500 | if (dctx->nonce_size < VMAC_NONCEBYTES) { |

501 | n = min(len, VMAC_NONCEBYTES - dctx->nonce_size); |

502 | memcpy(&dctx->nonce.bytes[dctx->nonce_size], p, n); |

503 | dctx->nonce_size += n; |

504 | p += n; |

505 | len -= n; |

506 | } |

507 | |

508 | if (dctx->partial_size) { |

509 | n = min(len, VMAC_NHBYTES - dctx->partial_size); |

510 | memcpy(&dctx->partial[dctx->partial_size], p, n); |

511 | dctx->partial_size += n; |

512 | p += n; |

513 | len -= n; |

514 | if (dctx->partial_size == VMAC_NHBYTES) { |

515 | vhash_blocks(tctx, dctx, dctx->partial_words, 1); |

516 | dctx->partial_size = 0; |

517 | } |

518 | } |

519 | |

520 | if (len >= VMAC_NHBYTES) { |

521 | n = round_down(len, VMAC_NHBYTES); |

522 | /* TODO: 'p' may be misaligned here */ |

523 | vhash_blocks(tctx, dctx, (const __le64 *)p, n / VMAC_NHBYTES); |

524 | p += n; |

525 | len -= n; |

526 | } |

527 | |

528 | if (len) { |

529 | memcpy(dctx->partial, p, len); |

530 | dctx->partial_size = len; |

531 | } |

532 | |

533 | return 0; |

534 | } |

535 | |

536 | static u64 vhash_final(const struct vmac_tfm_ctx *tctx, |

537 | struct vmac_desc_ctx *dctx) |

538 | { |

539 | unsigned int partial = dctx->partial_size; |

540 | u64 ch = dctx->polytmp[0]; |

541 | u64 cl = dctx->polytmp[1]; |

542 | |

543 | /* L1 and L2-hash the final block if needed */ |

544 | if (partial) { |

545 | /* Zero-pad to next 128-bit boundary */ |

546 | unsigned int n = round_up(partial, 16); |

547 | u64 rh, rl; |

548 | |

549 | memset(&dctx->partial[partial], 0, n - partial); |

550 | nh_16(dctx->partial_words, tctx->nhkey, n / 8, rh, rl); |

551 | rh &= m62; |

552 | if (dctx->first_block_processed) |

553 | poly_step(ch, cl, tctx->polykey[0], tctx->polykey[1], |

554 | rh, rl); |

555 | else |

556 | ADD128(ch, cl, rh, rl); |

557 | } |

558 | |

559 | /* L3-hash the 128-bit output of L2-hash */ |

560 | return l3hash(ch, cl, tctx->l3key[0], tctx->l3key[1], partial * 8); |

561 | } |

562 | |

563 | static int vmac_final(struct shash_desc *desc, u8 *out) |

564 | { |

565 | const struct vmac_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm); |

566 | struct vmac_desc_ctx *dctx = shash_desc_ctx(desc); |

567 | int index; |

568 | u64 hash, pad; |

569 | |

570 | if (dctx->nonce_size != VMAC_NONCEBYTES) |

571 | return -EINVAL; |

572 | |

573 | /* |

574 | * The VMAC specification requires a nonce at least 1 bit shorter than |

575 | * the block cipher's block length, so we actually only accept a 127-bit |

576 | * nonce. We define the unused bit to be the first one and require that |

577 | * it be 0, so the needed prepending of a 0 bit is implicit. |

578 | */ |

579 | if (dctx->nonce.bytes[0] & 0x80) |

580 | return -EINVAL; |

581 | |

582 | /* Finish calculating the VHASH of the message */ |

583 | hash = vhash_final(tctx, dctx); |

584 | |

585 | /* Generate pseudorandom pad by encrypting the nonce */ |

586 | BUILD_BUG_ON(VMAC_NONCEBYTES != 2 * (VMAC_TAG_LEN / 8)); |

587 | index = dctx->nonce.bytes[VMAC_NONCEBYTES - 1] & 1; |

588 | dctx->nonce.bytes[VMAC_NONCEBYTES - 1] &= ~1; |

589 | crypto_cipher_encrypt_one(tctx->cipher, dctx->nonce.bytes, |

590 | dctx->nonce.bytes); |

591 | pad = be64_to_cpu(dctx->nonce.pads[index]); |

592 | |

593 | /* The VMAC is the sum of VHASH and the pseudorandom pad */ |

594 | put_unaligned_be64(hash + pad, out); |

595 | return 0; |

596 | } |

597 | |

598 | static int vmac_init_tfm(struct crypto_tfm *tfm) |

599 | { |

600 | struct crypto_instance *inst = crypto_tfm_alg_instance(tfm); |

601 | struct crypto_spawn *spawn = crypto_instance_ctx(inst); |

602 | struct vmac_tfm_ctx *tctx = crypto_tfm_ctx(tfm); |

603 | struct crypto_cipher *cipher; |

604 | |

605 | cipher = crypto_spawn_cipher(spawn); |

606 | if (IS_ERR(cipher)) |

607 | return PTR_ERR(cipher); |

608 | |

609 | tctx->cipher = cipher; |

610 | return 0; |

611 | } |

612 | |

613 | static void vmac_exit_tfm(struct crypto_tfm *tfm) |

614 | { |

615 | struct vmac_tfm_ctx *tctx = crypto_tfm_ctx(tfm); |

616 | |

617 | crypto_free_cipher(tctx->cipher); |

618 | } |

619 | |

620 | static int vmac_create(struct crypto_template *tmpl, struct rtattr **tb) |

621 | { |

622 | struct shash_instance *inst; |

623 | struct crypto_alg *alg; |

624 | int err; |

625 | |

626 | err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH); |

627 | if (err) |

628 | return err; |

629 | |

630 | alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, |

631 | CRYPTO_ALG_TYPE_MASK); |

632 | if (IS_ERR(alg)) |

633 | return PTR_ERR(alg); |

634 | |

635 | err = -EINVAL; |

636 | if (alg->cra_blocksize != VMAC_NONCEBYTES) |

637 | goto out_put_alg; |

638 | |

639 | inst = shash_alloc_instance(tmpl->name, alg); |

640 | err = PTR_ERR(inst); |

641 | if (IS_ERR(inst)) |

642 | goto out_put_alg; |

643 | |

644 | err = crypto_init_spawn(shash_instance_ctx(inst), alg, |

645 | shash_crypto_instance(inst), |

646 | CRYPTO_ALG_TYPE_MASK); |

647 | if (err) |

648 | goto out_free_inst; |

649 | |

650 | inst->alg.base.cra_priority = alg->cra_priority; |

651 | inst->alg.base.cra_blocksize = alg->cra_blocksize; |

652 | inst->alg.base.cra_alignmask = alg->cra_alignmask; |

653 | |

654 | inst->alg.base.cra_ctxsize = sizeof(struct vmac_tfm_ctx); |

655 | inst->alg.base.cra_init = vmac_init_tfm; |

656 | inst->alg.base.cra_exit = vmac_exit_tfm; |

657 | |

658 | inst->alg.descsize = sizeof(struct vmac_desc_ctx); |

659 | inst->alg.digestsize = VMAC_TAG_LEN / 8; |

660 | inst->alg.init = vmac_init; |

661 | inst->alg.update = vmac_update; |

662 | inst->alg.final = vmac_final; |

663 | inst->alg.setkey = vmac_setkey; |

664 | |

665 | err = shash_register_instance(tmpl, inst); |

666 | if (err) { |

667 | out_free_inst: |

668 | shash_free_instance(shash_crypto_instance(inst)); |

669 | } |

670 | |

671 | out_put_alg: |

672 | crypto_mod_put(alg); |

673 | return err; |

674 | } |

675 | |

676 | static struct crypto_template vmac64_tmpl = { |

677 | .name = "vmac64", |

678 | .create = vmac_create, |

679 | .free = shash_free_instance, |

680 | .module = THIS_MODULE, |

681 | }; |

682 | |

683 | static int __init vmac_module_init(void) |

684 | { |

685 | return crypto_register_template(&vmac64_tmpl); |

686 | } |

687 | |

688 | static void __exit vmac_module_exit(void) |

689 | { |

690 | crypto_unregister_template(&vmac64_tmpl); |

691 | } |

692 | |

693 | module_init(vmac_module_init); |

694 | module_exit(vmac_module_exit); |

695 | |

696 | MODULE_LICENSE("GPL"); |

697 | MODULE_DESCRIPTION("VMAC hash algorithm"); |

698 | MODULE_ALIAS_CRYPTO("vmac64"); |

699 |