1 // SPDX-License-Identifier: BSD-2-Clause 2 /* 3 * Copyright (c) 2018, Linaro limited 4 */ 5 #include <assert.h> 6 #include <mbedtls/bignum.h> 7 #include <mempool.h> 8 #include <stdio.h> 9 #include <string.h> 10 #include <tee_api.h> 11 #include <tee_arith_internal.h> 12 #include <utee_defines.h> 13 #include <utee_syscalls.h> 14 #include <util.h> 15 16 #define MPI_MEMPOOL_SIZE (12 * 1024) 17 18 static void __noreturn api_panic(const char *func, int line, const char *msg) 19 { 20 printf("Panic function %s, line %d: %s\n", func, line, msg); 21 TEE_Panic(0xB16127 /*BIGINT*/); 22 while (1) 23 ; /* Panic will crash the thread */ 24 } 25 26 #define API_PANIC(x) api_panic(__func__, __LINE__, x) 27 28 static void __noreturn mpi_panic(const char *func, int line, int rc) 29 { 30 printf("Panic function %s, line %d, code %d\n", func, line, rc); 31 TEE_Panic(0xB16127 /*BIGINT*/); 32 while (1) 33 ; /* Panic will crash the thread */ 34 } 35 36 #define MPI_CHECK(x) do { \ 37 int _rc = (x); \ 38 \ 39 if (_rc) \ 40 mpi_panic(__func__, __LINE__, _rc); \ 41 } while (0) 42 43 void _TEE_MathAPI_Init(void) 44 { 45 static uint8_t data[MPI_MEMPOOL_SIZE] __aligned(MEMPOOL_ALIGN); 46 47 mbedtls_mpi_mempool = mempool_alloc_pool(data, sizeof(data), NULL); 48 if (!mbedtls_mpi_mempool) 49 API_PANIC("Failed to initialize memory pool"); 50 } 51 52 struct bigint_hdr { 53 int32_t sign; 54 uint16_t alloc_size; 55 uint16_t nblimbs; 56 }; 57 58 #define BIGINT_HDR_SIZE_IN_U32 2 59 60 static TEE_Result copy_mpi_to_bigint(mbedtls_mpi *mpi, TEE_BigInt *bigInt) 61 { 62 struct bigint_hdr *hdr = (struct bigint_hdr *)bigInt; 63 size_t n = mpi->n; 64 65 /* Trim of eventual insignificant zeroes */ 66 while (n && !mpi->p[n - 1]) 67 n--; 68 69 if (hdr->alloc_size < n) 70 return TEE_ERROR_OVERFLOW; 71 72 hdr->nblimbs = n; 73 hdr->sign = mpi->s; 74 memcpy(hdr + 1, mpi->p, mpi->n * sizeof(mbedtls_mpi_uint)); 75 76 return TEE_SUCCESS; 77 } 78 79 /* 80 * Initializes a MPI. 81 * 82 * A temporary MPI is allocated and if a bigInt is supplied the MPI is 83 * initialized with the value of the bigInt. 84 */ 85 static void get_mpi(mbedtls_mpi *mpi, const TEE_BigInt *bigInt) 86 { 87 /* 88 * The way the GP spec is defining the bignums it's 89 * difficult/tricky to do it using 64-bit arithmetics given that 90 * we'd need 64-bit alignment of the data as well. 91 */ 92 COMPILE_TIME_ASSERT(sizeof(mbedtls_mpi_uint) == sizeof(uint32_t)); 93 94 /* 95 * The struct bigint_hdr is the overhead added to the bigint and 96 * is required to take exactly 2 uint32_t. 97 */ 98 COMPILE_TIME_ASSERT(sizeof(struct bigint_hdr) == 99 sizeof(uint32_t) * BIGINT_HDR_SIZE_IN_U32); 100 101 mbedtls_mpi_init_mempool(mpi); 102 103 if (bigInt) { 104 const struct bigint_hdr *hdr = (struct bigint_hdr *)bigInt; 105 const mbedtls_mpi_uint *p = (const mbedtls_mpi_uint *)(hdr + 1); 106 size_t n = hdr->nblimbs; 107 108 /* Trim of eventual insignificant zeroes */ 109 while (n && !p[n - 1]) 110 n--; 111 112 MPI_CHECK(mbedtls_mpi_grow(mpi, n)); 113 mpi->s = hdr->sign; 114 memcpy(mpi->p, p, n * sizeof(mbedtls_mpi_uint)); 115 } 116 } 117 118 void TEE_BigIntInit(TEE_BigInt *bigInt, size_t len) 119 { 120 struct bigint_hdr *hdr = (struct bigint_hdr *)bigInt; 121 122 static_assert(MBEDTLS_MPI_MAX_LIMBS + BIGINT_HDR_SIZE_IN_U32 >= 123 CFG_TA_BIGNUM_MAX_BITS / 32); 124 125 memset(bigInt, 0, len * sizeof(uint32_t)); 126 hdr->sign = 1; 127 128 /* "gpd.tee.arith.maxBigIntSize" is assigned CFG_TA_BIGNUM_MAX_BITS */ 129 if (len > CFG_TA_BIGNUM_MAX_BITS / 4) 130 API_PANIC("Too large bigint"); 131 hdr->alloc_size = len - BIGINT_HDR_SIZE_IN_U32; 132 } 133 134 void __GP11_TEE_BigIntInit(TEE_BigInt *bigInt, uint32_t len) 135 { 136 TEE_BigIntInit(bigInt, len); 137 } 138 139 TEE_Result TEE_BigIntConvertFromOctetString(TEE_BigInt *dest, 140 const uint8_t *buffer, 141 size_t bufferLen, int32_t sign) 142 { 143 TEE_Result res; 144 mbedtls_mpi mpi_dest; 145 146 get_mpi(&mpi_dest, NULL); 147 148 if (mbedtls_mpi_read_binary(&mpi_dest, buffer, bufferLen)) 149 res = TEE_ERROR_OVERFLOW; 150 else 151 res = TEE_SUCCESS; 152 153 if (sign < 0) 154 mpi_dest.s = -1; 155 156 if (!res) 157 res = copy_mpi_to_bigint(&mpi_dest, dest); 158 159 mbedtls_mpi_free(&mpi_dest); 160 161 return res; 162 } 163 164 TEE_Result __GP11_TEE_BigIntConvertFromOctetString(TEE_BigInt *dest, 165 const uint8_t *buffer, 166 uint32_t bufferLen, 167 int32_t sign) 168 { 169 return TEE_BigIntConvertFromOctetString(dest, buffer, bufferLen, sign); 170 } 171 172 TEE_Result TEE_BigIntConvertToOctetString(uint8_t *buffer, size_t *bufferLen, 173 const TEE_BigInt *bigInt) 174 { 175 TEE_Result res = TEE_SUCCESS; 176 mbedtls_mpi mpi; 177 size_t sz; 178 179 get_mpi(&mpi, bigInt); 180 181 sz = mbedtls_mpi_size(&mpi); 182 if (sz <= *bufferLen) 183 MPI_CHECK(mbedtls_mpi_write_binary(&mpi, buffer, sz)); 184 else 185 res = TEE_ERROR_SHORT_BUFFER; 186 187 *bufferLen = sz; 188 189 mbedtls_mpi_free(&mpi); 190 191 return res; 192 } 193 194 TEE_Result __GP11_TEE_BigIntConvertToOctetString(uint8_t *buffer, 195 uint32_t *bufferLen, 196 const TEE_BigInt *bigInt) 197 { 198 TEE_Result res = TEE_SUCCESS; 199 size_t l = *bufferLen; 200 201 res = TEE_BigIntConvertToOctetString(buffer, &l, bigInt); 202 *bufferLen = l; 203 return res; 204 } 205 206 void TEE_BigIntConvertFromS32(TEE_BigInt *dest, int32_t shortVal) 207 { 208 mbedtls_mpi mpi; 209 210 get_mpi(&mpi, dest); 211 212 MPI_CHECK(mbedtls_mpi_lset(&mpi, shortVal)); 213 214 MPI_CHECK(copy_mpi_to_bigint(&mpi, dest)); 215 mbedtls_mpi_free(&mpi); 216 } 217 218 TEE_Result TEE_BigIntConvertToS32(int32_t *dest, const TEE_BigInt *src) 219 { 220 TEE_Result res = TEE_SUCCESS; 221 mbedtls_mpi mpi; 222 uint32_t v; 223 224 get_mpi(&mpi, src); 225 226 if (mbedtls_mpi_write_binary(&mpi, (void *)&v, sizeof(v))) { 227 res = TEE_ERROR_OVERFLOW; 228 goto out; 229 } 230 231 if (mpi.s > 0) { 232 if (ADD_OVERFLOW(0, TEE_U32_FROM_BIG_ENDIAN(v), dest)) 233 res = TEE_ERROR_OVERFLOW; 234 } else { 235 if (SUB_OVERFLOW(0, TEE_U32_FROM_BIG_ENDIAN(v), dest)) 236 res = TEE_ERROR_OVERFLOW; 237 } 238 239 out: 240 mbedtls_mpi_free(&mpi); 241 242 return res; 243 } 244 245 int32_t TEE_BigIntCmp(const TEE_BigInt *op1, const TEE_BigInt *op2) 246 { 247 mbedtls_mpi mpi1; 248 mbedtls_mpi mpi2; 249 int32_t rc; 250 251 get_mpi(&mpi1, op1); 252 get_mpi(&mpi2, op2); 253 254 rc = mbedtls_mpi_cmp_mpi(&mpi1, &mpi2); 255 256 mbedtls_mpi_free(&mpi1); 257 mbedtls_mpi_free(&mpi2); 258 259 return rc; 260 } 261 262 int32_t TEE_BigIntCmpS32(const TEE_BigInt *op, int32_t shortVal) 263 { 264 mbedtls_mpi mpi; 265 int32_t rc; 266 267 get_mpi(&mpi, op); 268 269 rc = mbedtls_mpi_cmp_int(&mpi, shortVal); 270 271 mbedtls_mpi_free(&mpi); 272 273 return rc; 274 } 275 276 void TEE_BigIntShiftRight(TEE_BigInt *dest, const TEE_BigInt *op, size_t bits) 277 { 278 mbedtls_mpi mpi_dest; 279 mbedtls_mpi mpi_op; 280 281 get_mpi(&mpi_dest, dest); 282 283 if (dest == op) { 284 MPI_CHECK(mbedtls_mpi_shift_r(&mpi_dest, bits)); 285 goto out; 286 } 287 288 get_mpi(&mpi_op, op); 289 290 if (mbedtls_mpi_size(&mpi_dest) >= mbedtls_mpi_size(&mpi_op)) { 291 MPI_CHECK(mbedtls_mpi_copy(&mpi_dest, &mpi_op)); 292 MPI_CHECK(mbedtls_mpi_shift_r(&mpi_dest, bits)); 293 } else { 294 mbedtls_mpi mpi_t; 295 296 get_mpi(&mpi_t, NULL); 297 298 /* 299 * We're using a temporary buffer to avoid the corner case 300 * where destination is unexpectedly overflowed by up to 301 * @bits number of bits. 302 */ 303 MPI_CHECK(mbedtls_mpi_copy(&mpi_t, &mpi_op)); 304 MPI_CHECK(mbedtls_mpi_shift_r(&mpi_t, bits)); 305 MPI_CHECK(mbedtls_mpi_copy(&mpi_dest, &mpi_t)); 306 307 mbedtls_mpi_free(&mpi_t); 308 } 309 310 mbedtls_mpi_free(&mpi_op); 311 312 out: 313 MPI_CHECK(copy_mpi_to_bigint(&mpi_dest, dest)); 314 mbedtls_mpi_free(&mpi_dest); 315 } 316 317 void __GP11_TEE_BigIntShiftRight(TEE_BigInt *dest, const TEE_BigInt *op, 318 uint32_t bits) 319 { 320 TEE_BigIntShiftRight(dest, op, bits); 321 } 322 323 bool TEE_BigIntGetBit(const TEE_BigInt *src, uint32_t bitIndex) 324 { 325 bool rc; 326 mbedtls_mpi mpi; 327 328 get_mpi(&mpi, src); 329 330 rc = mbedtls_mpi_get_bit(&mpi, bitIndex); 331 332 mbedtls_mpi_free(&mpi); 333 334 return rc; 335 } 336 337 uint32_t TEE_BigIntGetBitCount(const TEE_BigInt *src) 338 { 339 uint32_t rc; 340 mbedtls_mpi mpi; 341 342 get_mpi(&mpi, src); 343 344 rc = mbedtls_mpi_bitlen(&mpi); 345 346 mbedtls_mpi_free(&mpi); 347 348 return rc; 349 } 350 351 TEE_Result TEE_BigIntAssign(TEE_BigInt *dest, const TEE_BigInt *src) 352 { 353 const struct bigint_hdr *src_hdr = (struct bigint_hdr *)src; 354 struct bigint_hdr *dst_hdr = (struct bigint_hdr *)dest; 355 356 if (dst_hdr == src_hdr) 357 return TEE_SUCCESS; 358 359 if (dst_hdr->alloc_size < src_hdr->nblimbs) 360 return TEE_ERROR_OVERFLOW; 361 362 dst_hdr->nblimbs = src_hdr->nblimbs; 363 dst_hdr->sign = src_hdr->sign; 364 memcpy(dst_hdr + 1, src_hdr + 1, src_hdr->nblimbs * sizeof(uint32_t)); 365 366 return TEE_SUCCESS; 367 } 368 369 static void bigint_binary(TEE_BigInt *dest, const TEE_BigInt *op1, 370 const TEE_BigInt *op2, 371 int (*func)(mbedtls_mpi *X, const mbedtls_mpi *A, 372 const mbedtls_mpi *B)) 373 { 374 mbedtls_mpi mpi_dest; 375 mbedtls_mpi mpi_op1; 376 mbedtls_mpi mpi_op2; 377 mbedtls_mpi *pop1 = &mpi_op1; 378 mbedtls_mpi *pop2 = &mpi_op2; 379 380 get_mpi(&mpi_dest, dest); 381 382 if (op1 == dest) 383 pop1 = &mpi_dest; 384 else 385 get_mpi(&mpi_op1, op1); 386 387 if (op2 == dest) 388 pop2 = &mpi_dest; 389 else if (op2 == op1) 390 pop2 = pop1; 391 else 392 get_mpi(&mpi_op2, op2); 393 394 MPI_CHECK(func(&mpi_dest, pop1, pop2)); 395 396 MPI_CHECK(copy_mpi_to_bigint(&mpi_dest, dest)); 397 mbedtls_mpi_free(&mpi_dest); 398 if (pop1 == &mpi_op1) 399 mbedtls_mpi_free(&mpi_op1); 400 if (pop2 == &mpi_op2) 401 mbedtls_mpi_free(&mpi_op2); 402 } 403 404 static void bigint_binary_mod(TEE_BigInt *dest, const TEE_BigInt *op1, 405 const TEE_BigInt *op2, const TEE_BigInt *n, 406 int (*func)(mbedtls_mpi *X, const mbedtls_mpi *A, 407 const mbedtls_mpi *B)) 408 { 409 mbedtls_mpi mpi_dest; 410 mbedtls_mpi mpi_op1; 411 mbedtls_mpi mpi_op2; 412 mbedtls_mpi mpi_n; 413 mbedtls_mpi *pop1 = &mpi_op1; 414 mbedtls_mpi *pop2 = &mpi_op2; 415 mbedtls_mpi mpi_t; 416 417 if (TEE_BigIntCmpS32(n, 2) < 0) 418 API_PANIC("Modulus is too short"); 419 420 get_mpi(&mpi_dest, dest); 421 get_mpi(&mpi_n, n); 422 423 if (op1 == dest) 424 pop1 = &mpi_dest; 425 else 426 get_mpi(&mpi_op1, op1); 427 428 if (op2 == dest) 429 pop2 = &mpi_dest; 430 else if (op2 == op1) 431 pop2 = pop1; 432 else 433 get_mpi(&mpi_op2, op2); 434 435 get_mpi(&mpi_t, NULL); 436 437 MPI_CHECK(func(&mpi_t, pop1, pop2)); 438 MPI_CHECK(mbedtls_mpi_mod_mpi(&mpi_dest, &mpi_t, &mpi_n)); 439 440 MPI_CHECK(copy_mpi_to_bigint(&mpi_dest, dest)); 441 mbedtls_mpi_free(&mpi_dest); 442 if (pop1 == &mpi_op1) 443 mbedtls_mpi_free(&mpi_op1); 444 if (pop2 == &mpi_op2) 445 mbedtls_mpi_free(&mpi_op2); 446 mbedtls_mpi_free(&mpi_t); 447 mbedtls_mpi_free(&mpi_n); 448 } 449 450 void TEE_BigIntAdd(TEE_BigInt *dest, const TEE_BigInt *op1, 451 const TEE_BigInt *op2) 452 { 453 bigint_binary(dest, op1, op2, mbedtls_mpi_add_mpi); 454 } 455 456 void TEE_BigIntSub(TEE_BigInt *dest, const TEE_BigInt *op1, 457 const TEE_BigInt *op2) 458 { 459 bigint_binary(dest, op1, op2, mbedtls_mpi_sub_mpi); 460 } 461 462 void TEE_BigIntNeg(TEE_BigInt *dest, const TEE_BigInt *src) 463 { 464 mbedtls_mpi mpi_dest; 465 466 get_mpi(&mpi_dest, dest); 467 468 if (dest != src) { 469 mbedtls_mpi mpi_src; 470 471 get_mpi(&mpi_src, src); 472 473 MPI_CHECK(mbedtls_mpi_copy(&mpi_dest, &mpi_src)); 474 475 mbedtls_mpi_free(&mpi_src); 476 } 477 478 mpi_dest.s *= -1; 479 480 MPI_CHECK(copy_mpi_to_bigint(&mpi_dest, dest)); 481 mbedtls_mpi_free(&mpi_dest); 482 } 483 484 void TEE_BigIntMul(TEE_BigInt *dest, const TEE_BigInt *op1, 485 const TEE_BigInt *op2) 486 { 487 size_t bs1 = TEE_BigIntGetBitCount(op1); 488 size_t bs2 = TEE_BigIntGetBitCount(op2); 489 size_t s = TEE_BigIntSizeInU32(bs1) + TEE_BigIntSizeInU32(bs2); 490 TEE_BigInt zero[TEE_BigIntSizeInU32(1)] = { 0 }; 491 TEE_BigInt *tmp = NULL; 492 493 tmp = mempool_alloc(mbedtls_mpi_mempool, sizeof(uint32_t) * s); 494 if (!tmp) 495 TEE_Panic(TEE_ERROR_OUT_OF_MEMORY); 496 497 TEE_BigIntInit(tmp, s); 498 TEE_BigIntInit(zero, TEE_BigIntSizeInU32(1)); 499 500 bigint_binary(tmp, op1, op2, mbedtls_mpi_mul_mpi); 501 502 TEE_BigIntAdd(dest, tmp, zero); 503 504 mempool_free(mbedtls_mpi_mempool, tmp); 505 } 506 507 void TEE_BigIntSquare(TEE_BigInt *dest, const TEE_BigInt *op) 508 { 509 TEE_BigIntMul(dest, op, op); 510 } 511 512 void TEE_BigIntDiv(TEE_BigInt *dest_q, TEE_BigInt *dest_r, 513 const TEE_BigInt *op1, const TEE_BigInt *op2) 514 { 515 mbedtls_mpi mpi_dest_q; 516 mbedtls_mpi mpi_dest_r; 517 mbedtls_mpi mpi_op1; 518 mbedtls_mpi mpi_op2; 519 mbedtls_mpi *pop1 = &mpi_op1; 520 mbedtls_mpi *pop2 = &mpi_op2; 521 522 get_mpi(&mpi_dest_q, dest_q); 523 get_mpi(&mpi_dest_r, dest_r); 524 525 if (op1 == dest_q) 526 pop1 = &mpi_dest_q; 527 else if (op1 == dest_r) 528 pop1 = &mpi_dest_r; 529 else 530 get_mpi(&mpi_op1, op1); 531 532 if (op2 == dest_q) 533 pop2 = &mpi_dest_q; 534 else if (op2 == dest_r) 535 pop2 = &mpi_dest_r; 536 else if (op2 == op1) 537 pop2 = pop1; 538 else 539 get_mpi(&mpi_op2, op2); 540 541 MPI_CHECK(mbedtls_mpi_div_mpi(&mpi_dest_q, &mpi_dest_r, pop1, pop2)); 542 543 if (dest_q) 544 MPI_CHECK(copy_mpi_to_bigint(&mpi_dest_q, dest_q)); 545 if (dest_r) 546 MPI_CHECK(copy_mpi_to_bigint(&mpi_dest_r, dest_r)); 547 mbedtls_mpi_free(&mpi_dest_q); 548 mbedtls_mpi_free(&mpi_dest_r); 549 if (pop1 == &mpi_op1) 550 mbedtls_mpi_free(&mpi_op1); 551 if (pop2 == &mpi_op2) 552 mbedtls_mpi_free(&mpi_op2); 553 } 554 555 void TEE_BigIntMod(TEE_BigInt *dest, const TEE_BigInt *op, const TEE_BigInt *n) 556 { 557 if (TEE_BigIntCmpS32(n, 2) < 0) 558 API_PANIC("Modulus is too short"); 559 560 bigint_binary(dest, op, n, mbedtls_mpi_mod_mpi); 561 } 562 563 void TEE_BigIntAddMod(TEE_BigInt *dest, const TEE_BigInt *op1, 564 const TEE_BigInt *op2, const TEE_BigInt *n) 565 { 566 bigint_binary_mod(dest, op1, op2, n, mbedtls_mpi_add_mpi); 567 } 568 569 void TEE_BigIntSubMod(TEE_BigInt *dest, const TEE_BigInt *op1, 570 const TEE_BigInt *op2, const TEE_BigInt *n) 571 { 572 bigint_binary_mod(dest, op1, op2, n, mbedtls_mpi_sub_mpi); 573 } 574 575 void TEE_BigIntMulMod(TEE_BigInt *dest, const TEE_BigInt *op1, 576 const TEE_BigInt *op2, const TEE_BigInt *n) 577 { 578 bigint_binary_mod(dest, op1, op2, n, mbedtls_mpi_mul_mpi); 579 } 580 581 void TEE_BigIntSquareMod(TEE_BigInt *dest, const TEE_BigInt *op, 582 const TEE_BigInt *n) 583 { 584 TEE_BigIntMulMod(dest, op, op, n); 585 } 586 587 void TEE_BigIntInvMod(TEE_BigInt *dest, const TEE_BigInt *op, 588 const TEE_BigInt *n) 589 { 590 mbedtls_mpi mpi_dest; 591 mbedtls_mpi mpi_op; 592 mbedtls_mpi mpi_n; 593 mbedtls_mpi *pop = &mpi_op; 594 595 if (TEE_BigIntCmpS32(n, 2) < 0 || TEE_BigIntCmpS32(op, 0) == 0) 596 API_PANIC("too small modulus or trying to invert zero"); 597 598 get_mpi(&mpi_dest, dest); 599 get_mpi(&mpi_n, n); 600 601 if (op == dest) 602 pop = &mpi_dest; 603 else 604 get_mpi(&mpi_op, op); 605 606 MPI_CHECK(mbedtls_mpi_inv_mod(&mpi_dest, pop, &mpi_n)); 607 608 MPI_CHECK(copy_mpi_to_bigint(&mpi_dest, dest)); 609 mbedtls_mpi_free(&mpi_dest); 610 mbedtls_mpi_free(&mpi_n); 611 if (pop == &mpi_op) 612 mbedtls_mpi_free(&mpi_op); 613 } 614 615 bool TEE_BigIntRelativePrime(const TEE_BigInt *op1, const TEE_BigInt *op2) 616 { 617 bool rc; 618 mbedtls_mpi mpi_op1; 619 mbedtls_mpi mpi_op2; 620 mbedtls_mpi *pop2 = &mpi_op2; 621 mbedtls_mpi gcd; 622 623 get_mpi(&mpi_op1, op1); 624 625 if (op2 == op1) 626 pop2 = &mpi_op1; 627 else 628 get_mpi(&mpi_op2, op2); 629 630 get_mpi(&gcd, NULL); 631 632 MPI_CHECK(mbedtls_mpi_gcd(&gcd, &mpi_op1, &mpi_op2)); 633 634 rc = !mbedtls_mpi_cmp_int(&gcd, 1); 635 636 mbedtls_mpi_free(&gcd); 637 mbedtls_mpi_free(&mpi_op1); 638 if (pop2 == &mpi_op2) 639 mbedtls_mpi_free(&mpi_op2); 640 641 return rc; 642 } 643 644 static bool mpi_is_odd(mbedtls_mpi *x) 645 { 646 return mbedtls_mpi_get_bit(x, 0); 647 } 648 649 static bool mpi_is_even(mbedtls_mpi *x) 650 { 651 return !mpi_is_odd(x); 652 } 653 654 /* 655 * Based on libmpa implementation __mpa_egcd(), modified to work with MPI 656 * instead. 657 */ 658 static void mpi_egcd(mbedtls_mpi *gcd, mbedtls_mpi *a, mbedtls_mpi *b, 659 mbedtls_mpi *x_in, mbedtls_mpi *y_in) 660 { 661 mbedtls_mpi_uint k; 662 mbedtls_mpi A; 663 mbedtls_mpi B; 664 mbedtls_mpi C; 665 mbedtls_mpi D; 666 mbedtls_mpi x; 667 mbedtls_mpi y; 668 mbedtls_mpi u; 669 670 get_mpi(&A, NULL); 671 get_mpi(&B, NULL); 672 get_mpi(&C, NULL); 673 get_mpi(&D, NULL); 674 get_mpi(&x, NULL); 675 get_mpi(&y, NULL); 676 get_mpi(&u, NULL); 677 678 /* have y < x from assumption */ 679 if (!mbedtls_mpi_cmp_int(y_in, 0)) { 680 MPI_CHECK(mbedtls_mpi_lset(a, 1)); 681 MPI_CHECK(mbedtls_mpi_lset(b, 0)); 682 MPI_CHECK(mbedtls_mpi_copy(gcd, x_in)); 683 goto out; 684 } 685 686 MPI_CHECK(mbedtls_mpi_copy(&x, x_in)); 687 MPI_CHECK(mbedtls_mpi_copy(&y, y_in)); 688 689 k = 0; 690 while (mpi_is_even(&x) && mpi_is_even(&y)) { 691 k++; 692 MPI_CHECK(mbedtls_mpi_shift_r(&x, 1)); 693 MPI_CHECK(mbedtls_mpi_shift_r(&y, 1)); 694 } 695 696 MPI_CHECK(mbedtls_mpi_copy(&u, &x)); 697 MPI_CHECK(mbedtls_mpi_copy(gcd, &y)); 698 MPI_CHECK(mbedtls_mpi_lset(&A, 1)); 699 MPI_CHECK(mbedtls_mpi_lset(&B, 0)); 700 MPI_CHECK(mbedtls_mpi_lset(&C, 0)); 701 MPI_CHECK(mbedtls_mpi_lset(&D, 1)); 702 703 while (mbedtls_mpi_cmp_int(&u, 0)) { 704 while (mpi_is_even(&u)) { 705 MPI_CHECK(mbedtls_mpi_shift_r(&u, 1)); 706 if (mpi_is_odd(&A) || mpi_is_odd(&B)) { 707 MPI_CHECK(mbedtls_mpi_add_mpi(&A, &A, &y)); 708 MPI_CHECK(mbedtls_mpi_sub_mpi(&B, &B, &x)); 709 } 710 MPI_CHECK(mbedtls_mpi_shift_r(&A, 1)); 711 MPI_CHECK(mbedtls_mpi_shift_r(&B, 1)); 712 } 713 714 while (mpi_is_even(gcd)) { 715 MPI_CHECK(mbedtls_mpi_shift_r(gcd, 1)); 716 if (mpi_is_odd(&C) || mpi_is_odd(&D)) { 717 MPI_CHECK(mbedtls_mpi_add_mpi(&C, &C, &y)); 718 MPI_CHECK(mbedtls_mpi_sub_mpi(&D, &D, &x)); 719 } 720 MPI_CHECK(mbedtls_mpi_shift_r(&C, 1)); 721 MPI_CHECK(mbedtls_mpi_shift_r(&D, 1)); 722 723 } 724 725 if (mbedtls_mpi_cmp_mpi(&u, gcd) >= 0) { 726 MPI_CHECK(mbedtls_mpi_sub_mpi(&u, &u, gcd)); 727 MPI_CHECK(mbedtls_mpi_sub_mpi(&A, &A, &C)); 728 MPI_CHECK(mbedtls_mpi_sub_mpi(&B, &B, &D)); 729 } else { 730 MPI_CHECK(mbedtls_mpi_sub_mpi(gcd, gcd, &u)); 731 MPI_CHECK(mbedtls_mpi_sub_mpi(&C, &C, &A)); 732 MPI_CHECK(mbedtls_mpi_sub_mpi(&D, &D, &B)); 733 } 734 } 735 736 MPI_CHECK(mbedtls_mpi_copy(a, &C)); 737 MPI_CHECK(mbedtls_mpi_copy(b, &D)); 738 MPI_CHECK(mbedtls_mpi_shift_l(gcd, k)); 739 740 out: 741 mbedtls_mpi_free(&A); 742 mbedtls_mpi_free(&B); 743 mbedtls_mpi_free(&C); 744 mbedtls_mpi_free(&D); 745 mbedtls_mpi_free(&x); 746 mbedtls_mpi_free(&y); 747 mbedtls_mpi_free(&u); 748 } 749 750 void TEE_BigIntComputeExtendedGcd(TEE_BigInt *gcd, TEE_BigInt *u, 751 TEE_BigInt *v, const TEE_BigInt *op1, 752 const TEE_BigInt *op2) 753 { 754 mbedtls_mpi mpi_gcd_res; 755 mbedtls_mpi mpi_op1; 756 mbedtls_mpi mpi_op2; 757 mbedtls_mpi *pop2 = &mpi_op2; 758 759 get_mpi(&mpi_gcd_res, gcd); 760 get_mpi(&mpi_op1, op1); 761 762 if (op2 == op1) 763 pop2 = &mpi_op1; 764 else 765 get_mpi(&mpi_op2, op2); 766 767 if (!u && !v) { 768 MPI_CHECK(mbedtls_mpi_gcd(&mpi_gcd_res, &mpi_op1, pop2)); 769 } else { 770 mbedtls_mpi mpi_u; 771 mbedtls_mpi mpi_v; 772 int8_t s1 = mpi_op1.s; 773 int8_t s2 = pop2->s; 774 int cmp; 775 776 mpi_op1.s = 1; 777 pop2->s = 1; 778 779 get_mpi(&mpi_u, u); 780 get_mpi(&mpi_v, v); 781 782 cmp = mbedtls_mpi_cmp_abs(&mpi_op1, pop2); 783 if (cmp == 0) { 784 MPI_CHECK(mbedtls_mpi_copy(&mpi_gcd_res, &mpi_op1)); 785 MPI_CHECK(mbedtls_mpi_lset(&mpi_u, 1)); 786 MPI_CHECK(mbedtls_mpi_lset(&mpi_v, 0)); 787 } else if (cmp > 0) { 788 mpi_egcd(&mpi_gcd_res, &mpi_u, &mpi_v, &mpi_op1, pop2); 789 } else { 790 mpi_egcd(&mpi_gcd_res, &mpi_v, &mpi_u, pop2, &mpi_op1); 791 } 792 793 mpi_u.s *= s1; 794 mpi_v.s *= s2; 795 796 MPI_CHECK(copy_mpi_to_bigint(&mpi_u, u)); 797 MPI_CHECK(copy_mpi_to_bigint(&mpi_v, v)); 798 mbedtls_mpi_free(&mpi_u); 799 mbedtls_mpi_free(&mpi_v); 800 } 801 802 MPI_CHECK(copy_mpi_to_bigint(&mpi_gcd_res, gcd)); 803 mbedtls_mpi_free(&mpi_gcd_res); 804 mbedtls_mpi_free(&mpi_op1); 805 if (pop2 == &mpi_op2) 806 mbedtls_mpi_free(&mpi_op2); 807 } 808 809 static int rng_read(void *ignored __unused, unsigned char *buf, size_t blen) 810 { 811 if (_utee_cryp_random_number_generate(buf, blen)) 812 return MBEDTLS_ERR_MPI_FILE_IO_ERROR; 813 return 0; 814 } 815 816 int32_t TEE_BigIntIsProbablePrime(const TEE_BigInt *op, 817 uint32_t confidenceLevel __unused) 818 { 819 int rc; 820 mbedtls_mpi mpi_op; 821 822 get_mpi(&mpi_op, op); 823 824 rc = mbedtls_mpi_is_prime(&mpi_op, rng_read, NULL); 825 826 mbedtls_mpi_free(&mpi_op); 827 828 if (rc) 829 return 0; 830 831 return 1; 832 } 833 834 /* 835 * Not so fast FMM implementation based on the normal big int functions. 836 * 837 * Note that these functions (along with all the other functions in this 838 * file) only are used directly by the TA doing bigint arithmetics on its 839 * own. Performance of RSA operations in TEE Internal API are not affected 840 * by this. 841 */ 842 void TEE_BigIntInitFMM(TEE_BigIntFMM *bigIntFMM, size_t len) 843 { 844 TEE_BigIntInit(bigIntFMM, len); 845 } 846 847 void __GP11_TEE_BigIntInitFMM(TEE_BigIntFMM *bigIntFMM, uint32_t len) 848 { 849 TEE_BigIntInitFMM(bigIntFMM, len); 850 } 851 852 void TEE_BigIntInitFMMContext(TEE_BigIntFMMContext *context __unused, 853 size_t len __unused, 854 const TEE_BigInt *modulus __unused) 855 { 856 } 857 858 void __GP11_TEE_BigIntInitFMMContext(TEE_BigIntFMMContext *context, 859 uint32_t len, const TEE_BigInt *modulus) 860 { 861 TEE_BigIntInitFMMContext(context, len, modulus); 862 } 863 864 TEE_Result TEE_BigIntInitFMMContext1(TEE_BigIntFMMContext *context __unused, 865 size_t len __unused, 866 const TEE_BigInt *modulus __unused) 867 { 868 return TEE_SUCCESS; 869 } 870 871 size_t TEE_BigIntFMMSizeInU32(size_t modulusSizeInBits) 872 { 873 return TEE_BigIntSizeInU32(modulusSizeInBits); 874 } 875 876 uint32_t __GP11_TEE_BigIntFMMSizeInU32(uint32_t modulusSizeInBits) 877 { 878 return TEE_BigIntFMMSizeInU32(modulusSizeInBits); 879 } 880 881 size_t TEE_BigIntFMMContextSizeInU32(size_t modulusSizeInBits __unused) 882 { 883 /* Return something larger than 0 to keep malloc() and friends happy */ 884 return 1; 885 } 886 887 uint32_t __GP11_TEE_BigIntFMMContextSizeInU32(uint32_t modulusSizeInBits) 888 { 889 return TEE_BigIntFMMContextSizeInU32(modulusSizeInBits); 890 } 891 892 void TEE_BigIntConvertToFMM(TEE_BigIntFMM *dest, const TEE_BigInt *src, 893 const TEE_BigInt *n, 894 const TEE_BigIntFMMContext *context __unused) 895 { 896 TEE_BigIntMod(dest, src, n); 897 } 898 899 void TEE_BigIntConvertFromFMM(TEE_BigInt *dest, const TEE_BigIntFMM *src, 900 const TEE_BigInt *n __unused, 901 const TEE_BigIntFMMContext *context __unused) 902 { 903 mbedtls_mpi mpi_dst; 904 mbedtls_mpi mpi_src; 905 906 get_mpi(&mpi_dst, dest); 907 get_mpi(&mpi_src, src); 908 909 MPI_CHECK(mbedtls_mpi_copy(&mpi_dst, &mpi_src)); 910 911 MPI_CHECK(copy_mpi_to_bigint(&mpi_dst, dest)); 912 mbedtls_mpi_free(&mpi_dst); 913 mbedtls_mpi_free(&mpi_src); 914 } 915 916 void TEE_BigIntComputeFMM(TEE_BigIntFMM *dest, const TEE_BigIntFMM *op1, 917 const TEE_BigIntFMM *op2, const TEE_BigInt *n, 918 const TEE_BigIntFMMContext *context __unused) 919 { 920 mbedtls_mpi mpi_dst; 921 mbedtls_mpi mpi_op1; 922 mbedtls_mpi mpi_op2; 923 mbedtls_mpi mpi_n; 924 mbedtls_mpi mpi_t; 925 926 get_mpi(&mpi_dst, dest); 927 get_mpi(&mpi_op1, op1); 928 get_mpi(&mpi_op2, op2); 929 get_mpi(&mpi_n, n); 930 get_mpi(&mpi_t, NULL); 931 932 MPI_CHECK(mbedtls_mpi_mul_mpi(&mpi_t, &mpi_op1, &mpi_op2)); 933 MPI_CHECK(mbedtls_mpi_mod_mpi(&mpi_dst, &mpi_t, &mpi_n)); 934 935 mbedtls_mpi_free(&mpi_t); 936 mbedtls_mpi_free(&mpi_n); 937 mbedtls_mpi_free(&mpi_op2); 938 mbedtls_mpi_free(&mpi_op1); 939 MPI_CHECK(copy_mpi_to_bigint(&mpi_dst, dest)); 940 mbedtls_mpi_free(&mpi_dst); 941 } 942