mirror of
https://github.com/kidfromjupiter/nearby.git
synced 2026-09-16 15:36:12 -04:00
Janusz Sobczak
f643f7a466
New features: * Smart Audio Source Switching. * Fast Pair for BLE-only devices. * Two byte salt size for improved security. Other changes: * Added optional encryption modules based on mbedtls. * Fixed build issues. * More verbose and readable logs.
122 lines
3.8 KiB
C
122 lines
3.8 KiB
C
// Copyright 2022 Google LLC
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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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//
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// MBEDTLS module
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//
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// Purpose: Implements the cryptographic functions used by fp-provider using the
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// MBEDTLS package developed by ARM.
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//
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// To use the package, uncomment the NEARBY_PLATFORM_USE_MBEDTLS define in
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// config.mk.
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//
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// The following features are implemented here:
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//
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// nearby_platform_Sha256Start(), nearby_platform_Sha256Update(),
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// nearby_platform_Sha256Finish()
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//
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// Implements the SHA function across and arbitrary length block. Partial
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// blocks can be sent, and the resulting SHA will be over all blocks.
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//
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// nearby_platform_Aes128Encrypt(), nearby_platform_Aes128Decrypt()
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//
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// Encrypt and decrypt a block of data with a given key.
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//
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// Note that the required function nearby_platform_GenSec256r1Secret() is in a
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// separate file, gen_secret.c.
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//
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#include <mbedtls/aes.h>
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#include <mbedtls/ecdh.h>
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#include <mbedtls/ecp.h>
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#include <mbedtls/md.h> /* generic interface */
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#include <mbedtls/sha256.h>
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#if (MBEDTLS_VERSION_NUMBER >= 0x03000000)
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#include <mbedtls/compat-2.x.h>
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#endif
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#include <nearby_platform_se.h>
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static mbedtls_sha256_context sha256_ctx;
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nearby_platform_status nearby_platform_Sha256Start() {
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nearby_platform_status status = kNearbyStatusError;
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mbedtls_sha256_init(&sha256_ctx);
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if (mbedtls_sha256_starts_ret(&sha256_ctx, 0) == 0) {
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status = kNearbyStatusOK;
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} else {
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mbedtls_sha256_free(&sha256_ctx);
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}
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return status;
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}
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nearby_platform_status nearby_platform_Sha256Update(const void* data,
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size_t length) {
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nearby_platform_status status = kNearbyStatusError;
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if (mbedtls_sha256_update_ret(&sha256_ctx, (const unsigned char*)data,
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length) == 0) {
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status = kNearbyStatusOK;
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} else {
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mbedtls_sha256_free(&sha256_ctx);
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}
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return status;
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}
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nearby_platform_status nearby_platform_Sha256Finish(uint8_t out[32]) {
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nearby_platform_status status = kNearbyStatusError;
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if (mbedtls_sha256_finish_ret(&sha256_ctx, out) == 0) {
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status = kNearbyStatusOK;
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}
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mbedtls_sha256_free(&sha256_ctx);
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return status;
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}
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/**
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* Encrypts a data block with AES128 in ECB mode.
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*/
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nearby_platform_status nearby_platform_Aes128Encrypt(
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const uint8_t input[AES_MESSAGE_SIZE_BYTES],
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uint8_t output[AES_MESSAGE_SIZE_BYTES],
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const uint8_t key[AES_MESSAGE_SIZE_BYTES]) {
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nearby_platform_status status = kNearbyStatusError;
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mbedtls_aes_context ctx;
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mbedtls_aes_init(&ctx);
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if (mbedtls_aes_setkey_enc(&ctx, key, 128) != 0) goto exit;
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if (mbedtls_aes_crypt_ecb(&ctx, MBEDTLS_AES_ENCRYPT, input, output) != 0)
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goto exit;
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status = kNearbyStatusOK;
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exit:
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mbedtls_aes_free(&ctx);
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return status;
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}
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/**
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* Decrypts a data block with AES128 in ECB mode.
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*/
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nearby_platform_status nearby_platform_Aes128Decrypt(
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const uint8_t input[AES_MESSAGE_SIZE_BYTES],
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uint8_t output[AES_MESSAGE_SIZE_BYTES],
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const uint8_t key[AES_MESSAGE_SIZE_BYTES]) {
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nearby_platform_status status = kNearbyStatusError;
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mbedtls_aes_context ctx;
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mbedtls_aes_init(&ctx);
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if (mbedtls_aes_setkey_dec(&ctx, key, 128) != 0) goto exit;
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if (mbedtls_aes_crypt_ecb(&ctx, MBEDTLS_AES_DECRYPT, input, output) != 0)
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goto exit;
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status = kNearbyStatusOK;
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exit:
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mbedtls_aes_free(&ctx);
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return status;
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}
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