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/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 if (!mbytes) 379 return; 380 381 BUG_ON(mbytes % VMAC_NHBYTES); 382 383 mptr = (u64 *)m; 384 i = mbytes / VMAC_NHBYTES; /* Must be non-zero */ 385 386 ch = ctx->polytmp[0]; 387 cl = ctx->polytmp[1]; 388 389 if (!ctx->first_block_processed) { 390 ctx->first_block_processed = 1; 391 nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl); 392 rh &= m62; 393 ADD128(ch, cl, rh, rl); 394 mptr += (VMAC_NHBYTES/sizeof(u64)); 395 i--; 396 } 397 398 while (i--) { 399 nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl); 400 rh &= m62; 401 poly_step(ch, cl, pkh, pkl, rh, rl); 402 mptr += (VMAC_NHBYTES/sizeof(u64)); 403 } 404 405 ctx->polytmp[0] = ch; 406 ctx->polytmp[1] = cl; 407 } 408 409 static u64 vhash(unsigned char m[], unsigned int mbytes, 410 u64 *tagl, struct vmac_ctx *ctx) 411 { 412 u64 rh, rl, *mptr; 413 const u64 *kptr = (u64 *)ctx->nhkey; 414 int i, remaining; 415 u64 ch, cl; 416 u64 pkh = ctx->polykey[0]; 417 u64 pkl = ctx->polykey[1]; 418 419 mptr = (u64 *)m; 420 i = mbytes / VMAC_NHBYTES; 421 remaining = mbytes % VMAC_NHBYTES; 422 423 if (ctx->first_block_processed) { 424 ch = ctx->polytmp[0]; 425 cl = ctx->polytmp[1]; 426 } else if (i) { 427 nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, ch, cl); 428 ch &= m62; 429 ADD128(ch, cl, pkh, pkl); 430 mptr += (VMAC_NHBYTES/sizeof(u64)); 431 i--; 432 } else if (remaining) { 433 nh_16(mptr, kptr, 2*((remaining+15)/16), ch, cl); 434 ch &= m62; 435 ADD128(ch, cl, pkh, pkl); 436 mptr += (VMAC_NHBYTES/sizeof(u64)); 437 goto do_l3; 438 } else {/* Empty String */ 439 ch = pkh; cl = pkl; 440 goto do_l3; 441 } 442 443 while (i--) { 444 nh_vmac_nhbytes(mptr, kptr, VMAC_NHBYTES/8, rh, rl); 445 rh &= m62; 446 poly_step(ch, cl, pkh, pkl, rh, rl); 447 mptr += (VMAC_NHBYTES/sizeof(u64)); 448 } 449 if (remaining) { 450 nh_16(mptr, kptr, 2*((remaining+15)/16), rh, rl); 451 rh &= m62; 452 poly_step(ch, cl, pkh, pkl, rh, rl); 453 } 454 455 do_l3: 456 vhash_abort(ctx); 457 remaining *= 8; 458 return l3hash(ch, cl, ctx->l3key[0], ctx->l3key[1], remaining); 459 } 460 461 static u64 vmac(unsigned char m[], unsigned int mbytes, 462 const unsigned char n[16], u64 *tagl, 463 struct vmac_ctx_t *ctx) 464 { 465 u64 *in_n, *out_p; 466 u64 p, h; 467 int i; 468 469 in_n = ctx->__vmac_ctx.cached_nonce; 470 out_p = ctx->__vmac_ctx.cached_aes; 471 472 i = n[15] & 1; 473 if ((*(u64 *)(n+8) != in_n[1]) || (*(u64 *)(n) != in_n[0])) { 474 in_n[0] = *(u64 *)(n); 475 in_n[1] = *(u64 *)(n+8); 476 ((unsigned char *)in_n)[15] &= 0xFE; 477 crypto_cipher_encrypt_one(ctx->child, 478 (unsigned char *)out_p, (unsigned char *)in_n); 479 480 ((unsigned char *)in_n)[15] |= (unsigned char)(1-i); 481 } 482 p = be64_to_cpup(out_p + i); 483 h = vhash(m, mbytes, (u64 *)0, &ctx->__vmac_ctx); 484 return le64_to_cpu(p + h); 485 } 486 487 static int vmac_set_key(unsigned char user_key[], struct vmac_ctx_t *ctx) 488 { 489 u64 in[2] = {0}, out[2]; 490 unsigned i; 491 int err = 0; 492 493 err = crypto_cipher_setkey(ctx->child, user_key, VMAC_KEY_LEN); 494 if (err) 495 return err; 496 497 /* Fill nh key */ 498 ((unsigned char *)in)[0] = 0x80; 499 for (i = 0; i < sizeof(ctx->__vmac_ctx.nhkey)/8; i += 2) { 500 crypto_cipher_encrypt_one(ctx->child, 501 (unsigned char *)out, (unsigned char *)in); 502 ctx->__vmac_ctx.nhkey[i] = be64_to_cpup(out); 503 ctx->__vmac_ctx.nhkey[i+1] = be64_to_cpup(out+1); 504 ((unsigned char *)in)[15] += 1; 505 } 506 507 /* Fill poly key */ 508 ((unsigned char *)in)[0] = 0xC0; 509 in[1] = 0; 510 for (i = 0; i < sizeof(ctx->__vmac_ctx.polykey)/8; i += 2) { 511 crypto_cipher_encrypt_one(ctx->child, 512 (unsigned char *)out, (unsigned char *)in); 513 ctx->__vmac_ctx.polytmp[i] = 514 ctx->__vmac_ctx.polykey[i] = 515 be64_to_cpup(out) & mpoly; 516 ctx->__vmac_ctx.polytmp[i+1] = 517 ctx->__vmac_ctx.polykey[i+1] = 518 be64_to_cpup(out+1) & mpoly; 519 ((unsigned char *)in)[15] += 1; 520 } 521 522 /* Fill ip key */ 523 ((unsigned char *)in)[0] = 0xE0; 524 in[1] = 0; 525 for (i = 0; i < sizeof(ctx->__vmac_ctx.l3key)/8; i += 2) { 526 do { 527 crypto_cipher_encrypt_one(ctx->child, 528 (unsigned char *)out, (unsigned char *)in); 529 ctx->__vmac_ctx.l3key[i] = be64_to_cpup(out); 530 ctx->__vmac_ctx.l3key[i+1] = be64_to_cpup(out+1); 531 ((unsigned char *)in)[15] += 1; 532 } while (ctx->__vmac_ctx.l3key[i] >= p64 533 || ctx->__vmac_ctx.l3key[i+1] >= p64); 534 } 535 536 /* Invalidate nonce/aes cache and reset other elements */ 537 ctx->__vmac_ctx.cached_nonce[0] = (u64)-1; /* Ensure illegal nonce */ 538 ctx->__vmac_ctx.cached_nonce[1] = (u64)0; /* Ensure illegal nonce */ 539 ctx->__vmac_ctx.first_block_processed = 0; 540 541 return err; 542 } 543 544 static int vmac_setkey(struct crypto_shash *parent, 545 const u8 *key, unsigned int keylen) 546 { 547 struct vmac_ctx_t *ctx = crypto_shash_ctx(parent); 548 549 if (keylen != VMAC_KEY_LEN) { 550 crypto_shash_set_flags(parent, CRYPTO_TFM_RES_BAD_KEY_LEN); 551 return -EINVAL; 552 } 553 554 return vmac_set_key((u8 *)key, ctx); 555 } 556 557 static int vmac_init(struct shash_desc *pdesc) 558 { 559 return 0; 560 } 561 562 static int vmac_update(struct shash_desc *pdesc, const u8 *p, 563 unsigned int len) 564 { 565 struct crypto_shash *parent = pdesc->tfm; 566 struct vmac_ctx_t *ctx = crypto_shash_ctx(parent); 567 int expand; 568 int min; 569 570 expand = VMAC_NHBYTES - ctx->partial_size > 0 ? 571 VMAC_NHBYTES - ctx->partial_size : 0; 572 573 min = len < expand ? len : expand; 574 575 memcpy(ctx->partial + ctx->partial_size, p, min); 576 ctx->partial_size += min; 577 578 if (len < expand) 579 return 0; 580 581 vhash_update(ctx->partial, VMAC_NHBYTES, &ctx->__vmac_ctx); 582 ctx->partial_size = 0; 583 584 len -= expand; 585 p += expand; 586 587 if (len % VMAC_NHBYTES) { 588 memcpy(ctx->partial, p + len - (len % VMAC_NHBYTES), 589 len % VMAC_NHBYTES); 590 ctx->partial_size = len % VMAC_NHBYTES; 591 } 592 593 vhash_update(p, len - len % VMAC_NHBYTES, &ctx->__vmac_ctx); 594 595 return 0; 596 } 597 598 static int vmac_final(struct shash_desc *pdesc, u8 *out) 599 { 600 struct crypto_shash *parent = pdesc->tfm; 601 struct vmac_ctx_t *ctx = crypto_shash_ctx(parent); 602 vmac_t mac; 603 u8 nonce[16] = {}; 604 605 /* vmac() ends up accessing outside the array bounds that 606 * we specify. In appears to access up to the next 2-word 607 * boundary. We'll just be uber cautious and zero the 608 * unwritten bytes in the buffer. 609 */ 610 if (ctx->partial_size) { 611 memset(ctx->partial + ctx->partial_size, 0, 612 VMAC_NHBYTES - ctx->partial_size); 613 } 614 mac = vmac(ctx->partial, ctx->partial_size, nonce, NULL, ctx); 615 memcpy(out, &mac, sizeof(vmac_t)); 616 memzero_explicit(&mac, sizeof(vmac_t)); 617 memset(&ctx->__vmac_ctx, 0, sizeof(struct vmac_ctx)); 618 ctx->partial_size = 0; 619 return 0; 620 } 621 622 static int vmac_init_tfm(struct crypto_tfm *tfm) 623 { 624 struct crypto_cipher *cipher; 625 struct crypto_instance *inst = (void *)tfm->__crt_alg; 626 struct crypto_spawn *spawn = crypto_instance_ctx(inst); 627 struct vmac_ctx_t *ctx = crypto_tfm_ctx(tfm); 628 629 cipher = crypto_spawn_cipher(spawn); 630 if (IS_ERR(cipher)) 631 return PTR_ERR(cipher); 632 633 ctx->child = cipher; 634 return 0; 635 } 636 637 static void vmac_exit_tfm(struct crypto_tfm *tfm) 638 { 639 struct vmac_ctx_t *ctx = crypto_tfm_ctx(tfm); 640 crypto_free_cipher(ctx->child); 641 } 642 643 static int vmac_create(struct crypto_template *tmpl, struct rtattr **tb) 644 { 645 struct shash_instance *inst; 646 struct crypto_alg *alg; 647 int err; 648 649 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH); 650 if (err) 651 return err; 652 653 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER, 654 CRYPTO_ALG_TYPE_MASK); 655 if (IS_ERR(alg)) 656 return PTR_ERR(alg); 657 658 inst = shash_alloc_instance("vmac", alg); 659 err = PTR_ERR(inst); 660 if (IS_ERR(inst)) 661 goto out_put_alg; 662 663 err = crypto_init_spawn(shash_instance_ctx(inst), alg, 664 shash_crypto_instance(inst), 665 CRYPTO_ALG_TYPE_MASK); 666 if (err) 667 goto out_free_inst; 668 669 inst->alg.base.cra_priority = alg->cra_priority; 670 inst->alg.base.cra_blocksize = alg->cra_blocksize; 671 inst->alg.base.cra_alignmask = alg->cra_alignmask; 672 673 inst->alg.digestsize = sizeof(vmac_t); 674 inst->alg.base.cra_ctxsize = sizeof(struct vmac_ctx_t); 675 inst->alg.base.cra_init = vmac_init_tfm; 676 inst->alg.base.cra_exit = vmac_exit_tfm; 677 678 inst->alg.init = vmac_init; 679 inst->alg.update = vmac_update; 680 inst->alg.final = vmac_final; 681 inst->alg.setkey = vmac_setkey; 682 683 err = shash_register_instance(tmpl, inst); 684 if (err) { 685 out_free_inst: 686 shash_free_instance(shash_crypto_instance(inst)); 687 } 688 689 out_put_alg: 690 crypto_mod_put(alg); 691 return err; 692 } 693 694 static struct crypto_template vmac_tmpl = { 695 .name = "vmac", 696 .create = vmac_create, 697 .free = shash_free_instance, 698 .module = THIS_MODULE, 699 }; 700 701 static int __init vmac_module_init(void) 702 { 703 return crypto_register_template(&vmac_tmpl); 704 } 705 706 static void __exit vmac_module_exit(void) 707 { 708 crypto_unregister_template(&vmac_tmpl); 709 } 710 711 module_init(vmac_module_init); 712 module_exit(vmac_module_exit); 713 714 MODULE_LICENSE("GPL"); 715 MODULE_DESCRIPTION("VMAC hash algorithm"); 716