David Benjamin
33d1049b1f
We use the standard Apache 2.0 file header, described in "APPENDIX: How to apply the Apache License to your work." This was primarily automated by running: git ls-tree -r --name-only HEAD | xargs go run ./util/relicense.go See go/boringssl-relicensing-triage for the results of triaging the output of the tool. As part of this, switch from taking fiat-crypto under MIT license to Apache 2.0. (It is licensed under MIT OR Apache-2.0 OR BSD-1-Clause.) The copyright_summary tool can also be used to confirm we didn't accidentally drop any copyright lines: # Run before the CL git grep -l Copyright | xargs go run ./util/copyright_summary.go -out /tmp/old.json # Run after the CL git grep -l Copyright | xargs go run ./util/copyright_summary.go -compare /tmp/old.json Bug: 364634028 Change-Id: I17c50e761e9d077a1f92e25969e50ed35e320c59 Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/75852 Reviewed-by: Bob Beck <bbe@google.com> Commit-Queue: David Benjamin <davidben@google.com> Reviewed-by: Adam Langley <agl@google.com>
217 lines
8.1 KiB
C++
217 lines
8.1 KiB
C++
// Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include <openssl/evp.h>
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#include <assert.h>
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#include <openssl/err.h>
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#include <openssl/mem.h>
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#include "../internal.h"
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// This file implements scrypt, described in RFC 7914.
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//
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// Note scrypt refers to both "blocks" and a "block size" parameter, r. These
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// are two different notions of blocks. A Salsa20 block is 64 bytes long,
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// represented in this implementation by 16 |uint32_t|s. |r| determines the
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// number of 64-byte Salsa20 blocks in a scryptBlockMix block, which is 2 * |r|
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// Salsa20 blocks. This implementation refers to them as Salsa20 blocks and
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// scrypt blocks, respectively.
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// A block_t is a Salsa20 block.
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typedef struct {
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uint32_t words[16];
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} block_t;
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static_assert(sizeof(block_t) == 64, "block_t has padding");
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// salsa208_word_specification implements the Salsa20/8 core function, also
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// described in RFC 7914, section 3. It modifies the block at |inout|
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// in-place.
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static void salsa208_word_specification(block_t *inout) {
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block_t x;
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OPENSSL_memcpy(&x, inout, sizeof(x));
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for (int i = 8; i > 0; i -= 2) {
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x.words[4] ^= CRYPTO_rotl_u32(x.words[0] + x.words[12], 7);
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x.words[8] ^= CRYPTO_rotl_u32(x.words[4] + x.words[0], 9);
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x.words[12] ^= CRYPTO_rotl_u32(x.words[8] + x.words[4], 13);
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x.words[0] ^= CRYPTO_rotl_u32(x.words[12] + x.words[8], 18);
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x.words[9] ^= CRYPTO_rotl_u32(x.words[5] + x.words[1], 7);
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x.words[13] ^= CRYPTO_rotl_u32(x.words[9] + x.words[5], 9);
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x.words[1] ^= CRYPTO_rotl_u32(x.words[13] + x.words[9], 13);
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x.words[5] ^= CRYPTO_rotl_u32(x.words[1] + x.words[13], 18);
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x.words[14] ^= CRYPTO_rotl_u32(x.words[10] + x.words[6], 7);
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x.words[2] ^= CRYPTO_rotl_u32(x.words[14] + x.words[10], 9);
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x.words[6] ^= CRYPTO_rotl_u32(x.words[2] + x.words[14], 13);
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x.words[10] ^= CRYPTO_rotl_u32(x.words[6] + x.words[2], 18);
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x.words[3] ^= CRYPTO_rotl_u32(x.words[15] + x.words[11], 7);
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x.words[7] ^= CRYPTO_rotl_u32(x.words[3] + x.words[15], 9);
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x.words[11] ^= CRYPTO_rotl_u32(x.words[7] + x.words[3], 13);
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x.words[15] ^= CRYPTO_rotl_u32(x.words[11] + x.words[7], 18);
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x.words[1] ^= CRYPTO_rotl_u32(x.words[0] + x.words[3], 7);
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x.words[2] ^= CRYPTO_rotl_u32(x.words[1] + x.words[0], 9);
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x.words[3] ^= CRYPTO_rotl_u32(x.words[2] + x.words[1], 13);
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x.words[0] ^= CRYPTO_rotl_u32(x.words[3] + x.words[2], 18);
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x.words[6] ^= CRYPTO_rotl_u32(x.words[5] + x.words[4], 7);
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x.words[7] ^= CRYPTO_rotl_u32(x.words[6] + x.words[5], 9);
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x.words[4] ^= CRYPTO_rotl_u32(x.words[7] + x.words[6], 13);
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x.words[5] ^= CRYPTO_rotl_u32(x.words[4] + x.words[7], 18);
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x.words[11] ^= CRYPTO_rotl_u32(x.words[10] + x.words[9], 7);
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x.words[8] ^= CRYPTO_rotl_u32(x.words[11] + x.words[10], 9);
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x.words[9] ^= CRYPTO_rotl_u32(x.words[8] + x.words[11], 13);
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x.words[10] ^= CRYPTO_rotl_u32(x.words[9] + x.words[8], 18);
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x.words[12] ^= CRYPTO_rotl_u32(x.words[15] + x.words[14], 7);
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x.words[13] ^= CRYPTO_rotl_u32(x.words[12] + x.words[15], 9);
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x.words[14] ^= CRYPTO_rotl_u32(x.words[13] + x.words[12], 13);
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x.words[15] ^= CRYPTO_rotl_u32(x.words[14] + x.words[13], 18);
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}
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for (int i = 0; i < 16; ++i) {
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inout->words[i] += x.words[i];
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}
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}
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// xor_block sets |*out| to be |*a| XOR |*b|.
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static void xor_block(block_t *out, const block_t *a, const block_t *b) {
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for (size_t i = 0; i < 16; i++) {
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out->words[i] = a->words[i] ^ b->words[i];
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}
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}
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// scryptBlockMix implements the function described in RFC 7914, section 4. B'
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// is written to |out|. |out| and |B| may not alias and must be each one scrypt
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// block (2 * |r| Salsa20 blocks) long.
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static void scryptBlockMix(block_t *out, const block_t *B, uint64_t r) {
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assert(out != B);
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block_t X;
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OPENSSL_memcpy(&X, &B[r * 2 - 1], sizeof(X));
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for (uint64_t i = 0; i < r * 2; i++) {
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xor_block(&X, &X, &B[i]);
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salsa208_word_specification(&X);
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// This implements the permutation in step 3.
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OPENSSL_memcpy(&out[i / 2 + (i & 1) * r], &X, sizeof(X));
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}
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}
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// scryptROMix implements the function described in RFC 7914, section 5. |B| is
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// an scrypt block (2 * |r| Salsa20 blocks) and is modified in-place. |T| and
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// |V| are scratch space allocated by the caller. |T| must have space for one
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// scrypt block (2 * |r| Salsa20 blocks). |V| must have space for |N| scrypt
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// blocks (2 * |r| * |N| Salsa20 blocks).
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static void scryptROMix(block_t *B, uint64_t r, uint64_t N, block_t *T,
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block_t *V) {
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// Steps 1 and 2.
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OPENSSL_memcpy(V, B, 2 * r * sizeof(block_t));
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for (uint64_t i = 1; i < N; i++) {
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scryptBlockMix(&V[2 * r * i /* scrypt block i */],
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&V[2 * r * (i - 1) /* scrypt block i-1 */], r);
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}
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scryptBlockMix(B, &V[2 * r * (N - 1) /* scrypt block N-1 */], r);
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// Step 3.
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for (uint64_t i = 0; i < N; i++) {
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// Note this assumes |N| <= 2^32 and is a power of 2.
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uint32_t j = B[2 * r - 1].words[0] & (N - 1);
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for (size_t k = 0; k < 2 * r; k++) {
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xor_block(&T[k], &B[k], &V[2 * r * j + k]);
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}
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scryptBlockMix(B, T, r);
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}
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}
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// SCRYPT_PR_MAX is the maximum value of p * r. This is equivalent to the
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// bounds on p in section 6:
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//
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// p <= ((2^32-1) * hLen) / MFLen iff
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// p <= ((2^32-1) * 32) / (128 * r) iff
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// p * r <= (2^30-1)
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#define SCRYPT_PR_MAX ((1 << 30) - 1)
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// SCRYPT_MAX_MEM is the default maximum memory that may be allocated by
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// |EVP_PBE_scrypt|.
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#define SCRYPT_MAX_MEM (1024 * 1024 * 65)
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int EVP_PBE_scrypt(const char *password, size_t password_len,
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const uint8_t *salt, size_t salt_len, uint64_t N, uint64_t r,
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uint64_t p, size_t max_mem, uint8_t *out_key,
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size_t key_len) {
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if (r == 0 || p == 0 || p > SCRYPT_PR_MAX / r ||
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// |N| must be a power of two.
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N < 2 || (N & (N - 1)) ||
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// We only support |N| <= 2^32 in |scryptROMix|.
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N > UINT64_C(1) << 32 ||
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// Check that |N| < 2^(128×r / 8).
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(16 * r <= 63 && N >= UINT64_C(1) << (16 * r))) {
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OPENSSL_PUT_ERROR(EVP, EVP_R_INVALID_PARAMETERS);
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return 0;
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}
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// Determine the amount of memory needed. B, T, and V are |p|, 1, and |N|
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// scrypt blocks, respectively. Each scrypt block is 2*|r| |block_t|s.
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if (max_mem == 0) {
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max_mem = SCRYPT_MAX_MEM;
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}
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size_t max_scrypt_blocks = max_mem / (2 * r * sizeof(block_t));
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if (max_scrypt_blocks < p + 1 || max_scrypt_blocks - p - 1 < N) {
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OPENSSL_PUT_ERROR(EVP, EVP_R_MEMORY_LIMIT_EXCEEDED);
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return 0;
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}
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// Allocate and divide up the scratch space. |max_mem| fits in a size_t, which
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// is no bigger than uint64_t, so none of these operations may overflow.
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static_assert(UINT64_MAX >= SIZE_MAX, "size_t exceeds uint64_t");
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size_t B_blocks = p * 2 * r;
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size_t B_bytes = B_blocks * sizeof(block_t);
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size_t T_blocks = 2 * r;
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size_t V_blocks = N * 2 * r;
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block_t *B = reinterpret_cast<block_t *>(
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OPENSSL_calloc(B_blocks + T_blocks + V_blocks, sizeof(block_t)));
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if (B == NULL) {
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return 0;
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}
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int ret = 0;
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block_t *T = B + B_blocks;
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block_t *V = T + T_blocks;
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// NOTE: PKCS5_PBKDF2_HMAC can only fail due to allocation failure
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// or |iterations| of 0 (we pass 1 here). This is consistent with
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// the documented failure conditions of EVP_PBE_scrypt.
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if (!PKCS5_PBKDF2_HMAC(password, password_len, salt, salt_len, 1,
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EVP_sha256(), B_bytes, (uint8_t *)B)) {
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goto err;
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}
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for (uint64_t i = 0; i < p; i++) {
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scryptROMix(B + 2 * r * i, r, N, T, V);
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}
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if (!PKCS5_PBKDF2_HMAC(password, password_len, (const uint8_t *)B, B_bytes, 1,
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EVP_sha256(), key_len, out_key)) {
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goto err;
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}
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ret = 1;
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err:
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OPENSSL_free(B);
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return ret;
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}
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