746 lines
26 KiB
C
746 lines
26 KiB
C
/*
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* This file is part of the Pico FIDO distribution (https://github.com/polhenarejos/pico-fido).
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* Copyright (c) 2022 Pol Henarejos.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, version 3.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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#include "pico_keys.h"
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#ifndef ESP_PLATFORM
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#include "common.h"
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#else
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#define MBEDTLS_ALLOW_PRIVATE_ACCESS
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#endif
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#include "mbedtls/ecp.h"
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#include "mbedtls/ecdh.h"
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#include "mbedtls/sha256.h"
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#include "mbedtls/hkdf.h"
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#include "cbor.h"
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#include "ctap.h"
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#include "ctap2_cbor.h"
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#if defined(PICO_PLATFORM)
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#include "bsp/board.h"
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#endif
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#include "hid/ctap_hid.h"
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#include "fido.h"
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#include "files.h"
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#include "random.h"
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#include "crypto_utils.h"
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#include "apdu.h"
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#include "kek.h"
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uint32_t usage_timer = 0, initial_usage_time_limit = 0;
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uint32_t max_usage_time_period = 600 * 1000;
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bool needs_power_cycle = false;
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static mbedtls_ecdh_context hkey;
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static bool hkey_init = false;
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extern int encrypt_keydev_f1(const uint8_t keydev[32]);
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int beginUsingPinUvAuthToken(bool userIsPresent) {
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paut.user_present = userIsPresent;
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paut.user_verified = true;
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initial_usage_time_limit = board_millis();
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usage_timer = board_millis();
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paut.in_use = true;
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return 0;
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}
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void clearUserPresentFlag() {
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if (paut.in_use == true) {
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paut.user_present = false;
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}
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}
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void clearUserVerifiedFlag() {
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if (paut.in_use == true) {
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paut.user_verified = false;
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}
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}
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void clearPinUvAuthTokenPermissionsExceptLbw() {
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if (paut.in_use == true) {
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paut.permissions = CTAP_PERMISSION_LBW;
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}
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}
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void stopUsingPinUvAuthToken() {
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paut.permissions = 0;
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usage_timer = 0;
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paut.in_use = false;
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memset(paut.rp_id_hash, 0, sizeof(paut.rp_id_hash));
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paut.has_rp_id = false;
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initial_usage_time_limit = 0;
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paut.user_present = paut.user_verified = false;
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user_present_time_limit = 0;
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}
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bool getUserPresentFlagValue() {
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if (paut.in_use != true) {
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paut.user_present = false;
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}
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return paut.user_present;
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}
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bool getUserVerifiedFlagValue() {
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if (paut.in_use != true) {
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paut.user_verified = false;
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}
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return paut.user_verified;
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}
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int regenerate() {
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if (hkey_init == true) {
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mbedtls_ecdh_free(&hkey);
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}
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mbedtls_ecdh_init(&hkey);
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hkey_init = true;
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mbedtls_ecdh_setup(&hkey, MBEDTLS_ECP_DP_SECP256R1);
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int ret = mbedtls_ecdh_gen_public(&hkey.ctx.mbed_ecdh.grp, &hkey.ctx.mbed_ecdh.d, &hkey.ctx.mbed_ecdh.Q, random_gen, NULL);
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mbedtls_mpi_lset(&hkey.ctx.mbed_ecdh.Qp.Z, 1);
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if (ret != 0) {
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return ret;
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}
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return 0;
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}
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int kdf(uint8_t protocol, const mbedtls_mpi *z, uint8_t *sharedSecret) {
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int ret = 0;
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uint8_t buf[32];
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ret = mbedtls_mpi_write_binary(z, buf, sizeof(buf));
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if (ret != 0) {
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return ret;
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}
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if (protocol == 1) {
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return mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), buf, sizeof(buf), sharedSecret);
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}
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else if (protocol == 2) {
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const mbedtls_md_info_t *md_info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
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ret = mbedtls_hkdf(md_info, NULL, 0, buf, sizeof(buf), (uint8_t *) "CTAP2 HMAC key", 14, sharedSecret, 32);
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if (ret != 0) {
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return ret;
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}
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return mbedtls_hkdf(md_info, NULL, 0, buf, sizeof(buf), (uint8_t *) "CTAP2 AES key", 13, sharedSecret + 32, 32);
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}
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return -1;
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}
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int ecdh(uint8_t protocol, const mbedtls_ecp_point *Q, uint8_t *sharedSecret) {
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mbedtls_mpi z;
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mbedtls_mpi_init(&z);
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int ret = mbedtls_ecdh_compute_shared(&hkey.ctx.mbed_ecdh.grp, &z, Q, &hkey.ctx.mbed_ecdh.d, random_gen, NULL);
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ret = kdf(protocol, &z, sharedSecret);
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mbedtls_mpi_free(&z);
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return ret;
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}
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void resetAuthToken(bool persistent) {
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uint16_t fid = EF_AUTHTOKEN;
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if (persistent) {
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fid = EF_PAUTHTOKEN;
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}
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file_t *ef = search_by_fid(fid, NULL, SPECIFY_EF);
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uint8_t t[32];
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random_gen(NULL, t, sizeof(t));
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file_put_data(ef, t, sizeof(t));
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low_flash_available();
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}
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int resetPinUvAuthToken() {
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resetAuthToken(false);
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paut.permissions = 0;
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paut.data = file_get_data(ef_authtoken);
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paut.len = file_get_size(ef_authtoken);
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return 0;
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}
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int resetPersistentPinUvAuthToken() {
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resetAuthToken(true);
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file_t *ef_pauthtoken = search_by_fid(EF_PAUTHTOKEN, NULL, SPECIFY_EF);
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ppaut.permissions = 0;
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ppaut.data = file_get_data(ef_pauthtoken);
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ppaut.len = file_get_size(ef_pauthtoken);
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return 0;
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}
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int encrypt(uint8_t protocol, const uint8_t *key, const uint8_t *in, uint16_t in_len, uint8_t *out) {
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if (protocol == 1) {
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memcpy(out, in, in_len);
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return aes_encrypt(key, NULL, 32 * 8, PICO_KEYS_AES_MODE_CBC, out, in_len);
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}
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else if (protocol == 2) {
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random_gen(NULL, out, IV_SIZE);
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memcpy(out + IV_SIZE, in, in_len);
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return aes_encrypt(key + 32, out, 32 * 8, PICO_KEYS_AES_MODE_CBC, out + IV_SIZE, in_len);
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}
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return -1;
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}
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int decrypt(uint8_t protocol, const uint8_t *key, const uint8_t *in, uint16_t in_len, uint8_t *out) {
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if (protocol == 1) {
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memcpy(out, in, in_len);
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return aes_decrypt(key, NULL, 32 * 8, PICO_KEYS_AES_MODE_CBC, out, in_len);
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}
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else if (protocol == 2) {
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memcpy(out, in + IV_SIZE, in_len - IV_SIZE);
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return aes_decrypt(key + 32, in, 32 * 8, PICO_KEYS_AES_MODE_CBC, out, in_len - IV_SIZE);
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}
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return -1;
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}
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int authenticate(uint8_t protocol, const uint8_t *key, const uint8_t *data, size_t len, uint8_t *sign) {
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uint8_t hmac[32];
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int ret =
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mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), key, 32, data, len, hmac);
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if (ret != 0) {
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return ret;
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}
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if (protocol == 1) {
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memcpy(sign, hmac, 16);
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}
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else if (protocol == 2) {
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memcpy(sign, hmac, 32);
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}
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else {
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return -1;
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}
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return 0;
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}
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int verify(uint8_t protocol, const uint8_t *key, const uint8_t *data, uint16_t len, uint8_t *sign) {
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uint8_t hmac[32];
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//if (paut.in_use == false)
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// return -2;
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int ret = mbedtls_md_hmac(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), key, 32, data, len, hmac);
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if (ret != 0) {
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return ret;
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}
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if (protocol == 1) {
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return ct_memcmp(sign, hmac, 16);
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}
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else if (protocol == 2) {
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return ct_memcmp(sign, hmac, 32);
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}
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return -1;
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}
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int initialize() {
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regenerate();
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return resetPinUvAuthToken();
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}
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int getPublicKey() {
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return 0;
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}
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int pinUvAuthTokenUsageTimerObserver() {
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if (usage_timer == 0) {
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return -1;
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}
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if (usage_timer + max_usage_time_period > board_millis()) {
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if (user_present_time_limit == 0 ||
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user_present_time_limit + TRANSPORT_TIME_LIMIT < board_millis()) {
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clearUserPresentFlag();
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}
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if (paut.in_use == true) {
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if (initial_usage_time_limit == 0 ||
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initial_usage_time_limit + TRANSPORT_TIME_LIMIT < board_millis()) {
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stopUsingPinUvAuthToken();
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return 1;
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}
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}
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// TO DO: implement a rolling timer
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}
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return 0;
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}
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int check_keydev_encrypted(const uint8_t pin_token[32]) {
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if (file_get_data(ef_keydev) && *file_get_data(ef_keydev) == 0x01) {
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uint8_t tmp_keydev[61];
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tmp_keydev[0] = 0x02; // Change format to encrypted
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encrypt_with_aad(pin_token, file_get_data(ef_keydev) + 1, 32, tmp_keydev + 1);
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file_put_data(ef_keydev, tmp_keydev, sizeof(tmp_keydev));
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mbedtls_platform_zeroize(tmp_keydev, sizeof(tmp_keydev));
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low_flash_available();
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}
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return PICOKEY_OK;
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}
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uint8_t new_pin_mismatches = 0;
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int cbor_client_pin(const uint8_t *data, size_t len) {
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size_t resp_size = 0;
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uint64_t subcommand = 0x0, pinUvAuthProtocol = 0, permissions = 0;
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int64_t kty = 0, alg = 0, crv = 0;
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CborParser parser;
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CborEncoder encoder, mapEncoder;
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CborValue map;
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CborError error = CborNoError;
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CborByteString pinUvAuthParam = { 0 }, newPinEnc = { 0 }, pinHashEnc = { 0 }, kax = { 0 }, kay = { 0 };
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CborCharString rpId = { 0 };
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CBOR_CHECK(cbor_parser_init(data, len, 0, &parser, &map));
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uint64_t val_c = 1;
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uint8_t keydev[32] = {0};
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if (hkey_init == false) {
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initialize();
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}
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CBOR_PARSE_MAP_START(map, 1)
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{
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uint64_t val_u = 0;
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CBOR_FIELD_GET_UINT(val_u, 1);
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if (val_c <= 2 && val_c != val_u) {
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CBOR_ERROR(CTAP2_ERR_MISSING_PARAMETER);
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}
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if (val_u < val_c) {
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CBOR_ERROR(CTAP2_ERR_INVALID_CBOR);
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}
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val_c = val_u + 1;
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if (val_u == 0x01) {
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CBOR_FIELD_GET_UINT(pinUvAuthProtocol, 1);
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}
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else if (val_u == 0x02) {
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CBOR_FIELD_GET_UINT(subcommand, 1);
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}
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else if (val_u == 0x03) {
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CBOR_CHECK(COSE_read_key(&_f1, &kty, &alg, &crv, &kax, &kay));
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}
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else if (val_u == 0x04) {
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CBOR_FIELD_GET_BYTES(pinUvAuthParam, 1);
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}
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else if (val_u == 0x05) {
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CBOR_FIELD_GET_BYTES(newPinEnc, 1);
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}
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else if (val_u == 0x06) {
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CBOR_FIELD_GET_BYTES(pinHashEnc, 1);
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}
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else if (val_u == 0x09) {
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CBOR_FIELD_GET_UINT(permissions, 1);
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}
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else if (val_u == 0x0A) {
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CBOR_FIELD_GET_TEXT(rpId, 1);
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}
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}
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CBOR_PARSE_MAP_END(map, 1);
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cbor_encoder_init(&encoder, ctap_resp->init.data + 1, CTAP_MAX_CBOR_PAYLOAD, 0);
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if (subcommand == 0x0) {
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CBOR_ERROR(CTAP2_ERR_MISSING_PARAMETER);
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}
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else if (subcommand == 0x1) { //getPINRetries
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CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, needs_power_cycle ? 2 : 1));
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CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x03));
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CBOR_CHECK(cbor_encode_uint(&mapEncoder, (uint64_t) *file_get_data(ef_pin)));
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if (needs_power_cycle) {
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CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x04));
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CBOR_CHECK(cbor_encode_boolean(&mapEncoder, true));
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}
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}
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else if (subcommand == 0x2) { //getKeyAgreement
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if (pinUvAuthProtocol == 1 || pinUvAuthProtocol == 2) {
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CborEncoder mapEncoder2;
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CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, 1));
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CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x01));
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CBOR_CHECK(COSE_key_shared(&hkey, &mapEncoder, &mapEncoder2));
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}
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else if (pinUvAuthProtocol == 0) {
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CBOR_ERROR(CTAP2_ERR_MISSING_PARAMETER);
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}
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else {
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CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
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}
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}
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else if (subcommand == 0x3) { //setPIN
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if (kax.present == false || kay.present == false || pinUvAuthProtocol == 0 ||
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newPinEnc.present == false || pinUvAuthParam.present == false || alg == 0) {
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CBOR_ERROR(CTAP2_ERR_MISSING_PARAMETER);
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}
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if (pinUvAuthProtocol != 1 && pinUvAuthProtocol != 2) {
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CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
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}
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if (file_has_data(ef_pin)) {
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CBOR_ERROR(CTAP2_ERR_NOT_ALLOWED);
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}
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if ((pinUvAuthProtocol == 1 && newPinEnc.len != 64) ||
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(pinUvAuthProtocol == 2 && newPinEnc.len != 64 + IV_SIZE)) {
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CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
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}
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if (mbedtls_mpi_read_binary(&hkey.ctx.mbed_ecdh.Qp.X, kax.data, kax.len) != 0) {
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CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
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}
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if (mbedtls_mpi_read_binary(&hkey.ctx.mbed_ecdh.Qp.Y, kay.data, kay.len) != 0) {
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CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
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}
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uint8_t sharedSecret[64];
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int ret = ecdh((uint8_t)pinUvAuthProtocol, &hkey.ctx.mbed_ecdh.Qp, sharedSecret);
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if (ret != 0) {
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mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
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CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
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}
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if (verify((uint8_t)pinUvAuthProtocol, sharedSecret, newPinEnc.data, (uint16_t)newPinEnc.len, pinUvAuthParam.data) != 0) {
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mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
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CBOR_ERROR(CTAP2_ERR_PIN_AUTH_INVALID);
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}
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uint8_t paddedNewPin[64];
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ret = decrypt((uint8_t)pinUvAuthProtocol, sharedSecret, newPinEnc.data, (uint16_t)newPinEnc.len, paddedNewPin);
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mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
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if (ret != 0) {
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CBOR_ERROR(CTAP2_ERR_PIN_AUTH_INVALID);
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}
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if (paddedNewPin[63] != 0) {
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CBOR_ERROR(CTAP2_ERR_PIN_POLICY_VIOLATION);
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}
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uint8_t pin_len = 0;
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while (paddedNewPin[pin_len] != 0 && pin_len < sizeof(paddedNewPin)) {
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pin_len++;
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}
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uint8_t minPin = 4;
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file_t *ef_minpin = search_by_fid(EF_MINPINLEN, NULL, SPECIFY_EF);
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if (file_has_data(ef_minpin)) {
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minPin = *file_get_data(ef_minpin);
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}
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if (pin_len < minPin) {
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CBOR_ERROR(CTAP2_ERR_PIN_POLICY_VIOLATION);
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}
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uint8_t hsh[35], dhash[32];
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hsh[0] = MAX_PIN_RETRIES;
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hsh[1] = pin_len;
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hsh[2] = 1; // New format indicator
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mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), paddedNewPin, pin_len, dhash);
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pin_derive_verifier(dhash, 16, hsh + 3);
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file_put_data(ef_pin, hsh, sizeof(hsh));
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low_flash_available();
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pin_derive_session(dhash, 16, session_pin);
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ret = check_keydev_encrypted(session_pin);
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if (ret != PICOKEY_OK) {
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CBOR_ERROR(ret);
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}
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mbedtls_platform_zeroize(hsh, sizeof(hsh));
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mbedtls_platform_zeroize(dhash, sizeof(dhash));
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goto err; //No return
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}
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else if (subcommand == 0x4) { //changePIN
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if (kax.present == false || kay.present == false || pinUvAuthProtocol == 0 ||
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newPinEnc.present == false || pinUvAuthParam.present == false || alg == 0 ||
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pinHashEnc.present == false) {
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CBOR_ERROR(CTAP2_ERR_MISSING_PARAMETER);
|
|
}
|
|
if (pinUvAuthProtocol != 1 && pinUvAuthProtocol != 2) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
if (!file_has_data(ef_pin)) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_NOT_SET);
|
|
}
|
|
if (*file_get_data(ef_pin) == 0) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_BLOCKED);
|
|
}
|
|
if ((pinUvAuthProtocol == 1 && (newPinEnc.len != 64 || pinHashEnc.len != 16)) ||
|
|
(pinUvAuthProtocol == 2 &&
|
|
(newPinEnc.len != 64 + IV_SIZE || pinHashEnc.len != 16 + IV_SIZE))) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
if (mbedtls_mpi_read_binary(&hkey.ctx.mbed_ecdh.Qp.X, kax.data, kax.len) != 0) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
if (mbedtls_mpi_read_binary(&hkey.ctx.mbed_ecdh.Qp.Y, kay.data, kay.len) != 0) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
uint8_t sharedSecret[64];
|
|
int ret = ecdh((uint8_t)pinUvAuthProtocol, &hkey.ctx.mbed_ecdh.Qp, sharedSecret);
|
|
if (ret != 0) {
|
|
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
uint8_t tmp[80 + 32];
|
|
memcpy(tmp, newPinEnc.data, newPinEnc.len);
|
|
memcpy(tmp + newPinEnc.len, pinHashEnc.data, pinHashEnc.len);
|
|
if (verify((uint8_t)pinUvAuthProtocol, sharedSecret, tmp, (uint16_t)(newPinEnc.len + pinHashEnc.len), pinUvAuthParam.data) != 0) {
|
|
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
|
|
CBOR_ERROR(CTAP2_ERR_PIN_AUTH_INVALID);
|
|
}
|
|
uint8_t pin_data[35];
|
|
memcpy(pin_data, file_get_data(ef_pin), file_get_size(ef_pin));
|
|
pin_data[0] -= 1;
|
|
file_put_data(ef_pin, pin_data, file_get_size(ef_pin));
|
|
low_flash_available();
|
|
uint8_t retries = pin_data[0];
|
|
uint8_t paddedNewPin[64];
|
|
ret = decrypt((uint8_t)pinUvAuthProtocol, sharedSecret, pinHashEnc.data, (uint16_t)pinHashEnc.len, paddedNewPin);
|
|
if (ret != 0) {
|
|
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
|
|
CBOR_ERROR(CTAP2_ERR_PIN_AUTH_INVALID);
|
|
}
|
|
uint8_t dhash[32], off = 3;
|
|
if (file_get_size(ef_pin) == 34) {
|
|
off = 2;
|
|
double_hash_pin(paddedNewPin, 16, dhash);
|
|
}
|
|
else {
|
|
pin_derive_verifier(paddedNewPin, 16, dhash);
|
|
}
|
|
|
|
if (ct_memcmp(dhash, file_get_data(ef_pin) + off, 32) != 0) {
|
|
regenerate();
|
|
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
|
|
if (retries == 0) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_BLOCKED);
|
|
}
|
|
if (++new_pin_mismatches >= 3) {
|
|
needs_power_cycle = true;
|
|
CBOR_ERROR(CTAP2_ERR_PIN_AUTH_BLOCKED);
|
|
}
|
|
else {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_INVALID);
|
|
}
|
|
}
|
|
if (off == 2) {
|
|
// Upgrade pin file to new format
|
|
pin_data[2] = 1; // New format indicator
|
|
pin_derive_verifier(paddedNewPin, 16, pin_data + 3);
|
|
|
|
hash_multi(paddedNewPin, 16, session_pin);
|
|
ret = load_keydev(keydev);
|
|
if (ret != PICOKEY_OK) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_INVALID);
|
|
}
|
|
encrypt_keydev_f1(keydev);
|
|
}
|
|
pin_derive_session(paddedNewPin, 16, session_pin);
|
|
pin_data[0] = MAX_PIN_RETRIES;
|
|
file_put_data(ef_pin, pin_data, sizeof(pin_data));
|
|
low_flash_available();
|
|
|
|
ret = check_keydev_encrypted(session_pin);
|
|
if (ret != PICOKEY_OK) {
|
|
CBOR_ERROR(ret);
|
|
}
|
|
|
|
new_pin_mismatches = 0;
|
|
ret = decrypt((uint8_t)pinUvAuthProtocol, sharedSecret, newPinEnc.data, (uint16_t)newPinEnc.len, paddedNewPin);
|
|
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
|
|
if (ret != 0) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_AUTH_INVALID);
|
|
}
|
|
if (paddedNewPin[63] != 0) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
uint8_t pin_len = 0;
|
|
while (paddedNewPin[pin_len] != 0 && pin_len < sizeof(paddedNewPin)) {
|
|
pin_len++;
|
|
}
|
|
uint8_t minPin = 4;
|
|
file_t *ef_minpin = search_by_fid(EF_MINPINLEN, NULL, SPECIFY_EF);
|
|
if (file_has_data(ef_minpin)) {
|
|
minPin = *file_get_data(ef_minpin);
|
|
}
|
|
if (pin_len < minPin) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_POLICY_VIOLATION);
|
|
}
|
|
|
|
// New PIN is valid and verified
|
|
ret = load_keydev(keydev);
|
|
if (ret != PICOKEY_OK) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_INVALID);
|
|
}
|
|
encrypt_keydev_f1(keydev);
|
|
|
|
mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), paddedNewPin, pin_len, dhash);
|
|
pin_derive_session(dhash, 16, session_pin);
|
|
ret = check_keydev_encrypted(session_pin);
|
|
if (ret != PICOKEY_OK) {
|
|
CBOR_ERROR(ret);
|
|
}
|
|
low_flash_available();
|
|
|
|
pin_data[0] = MAX_PIN_RETRIES;
|
|
pin_data[1] = pin_len;
|
|
pin_data[2] = 1; // New format indicator
|
|
pin_derive_verifier(dhash, 16, pin_data + 3);
|
|
|
|
if (file_has_data(ef_minpin) && file_get_data(ef_minpin)[1] == 1 && ct_memcmp(pin_data + 3, file_get_data(ef_pin) + 3, 32) == 0) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_POLICY_VIOLATION);
|
|
}
|
|
file_put_data(ef_pin, pin_data, sizeof(pin_data));
|
|
|
|
mbedtls_platform_zeroize(pin_data, sizeof(pin_data));
|
|
mbedtls_platform_zeroize(dhash, sizeof(dhash));
|
|
if (file_has_data(ef_minpin) && file_get_data(ef_minpin)[1] == 1) {
|
|
uint8_t *tmpf = (uint8_t *) calloc(1, file_get_size(ef_minpin));
|
|
memcpy(tmpf, file_get_data(ef_minpin), file_get_size(ef_minpin));
|
|
tmpf[1] = 0;
|
|
file_put_data(ef_minpin, tmpf, file_get_size(ef_minpin));
|
|
free(tmpf);
|
|
}
|
|
low_flash_available();
|
|
resetPinUvAuthToken();
|
|
resetPersistentPinUvAuthToken();
|
|
goto err; // No return
|
|
}
|
|
else if (subcommand == 0x9 || subcommand == 0x5) { //getPinUvAuthTokenUsingPinWithPermissions
|
|
if (kax.present == false || kay.present == false || pinUvAuthProtocol == 0 || alg == 0 ||
|
|
pinHashEnc.present == false) {
|
|
CBOR_ERROR(CTAP2_ERR_MISSING_PARAMETER);
|
|
}
|
|
if (pinUvAuthProtocol != 1 && pinUvAuthProtocol != 2) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
if (subcommand == 0x5 && (permissions != 0 || rpId.present == true)) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
if (subcommand == 0x9) {
|
|
if (permissions == 0) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
if ((permissions & CTAP_PERMISSION_BE)) { // Not supported yet
|
|
CBOR_ERROR(CTAP2_ERR_UNAUTHORIZED_PERMISSION);
|
|
}
|
|
if ((permissions & CTAP_PERMISSION_PCMR) && permissions != CTAP_PERMISSION_PCMR) {
|
|
CBOR_ERROR(CTAP2_ERR_UNAUTHORIZED_PERMISSION);
|
|
}
|
|
}
|
|
if (!file_has_data(ef_pin)) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_NOT_SET);
|
|
}
|
|
if (*file_get_data(ef_pin) == 0) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_BLOCKED);
|
|
}
|
|
if (mbedtls_mpi_read_binary(&hkey.ctx.mbed_ecdh.Qp.X, kax.data, kax.len) != 0) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
if (mbedtls_mpi_read_binary(&hkey.ctx.mbed_ecdh.Qp.Y, kay.data, kay.len) != 0) {
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
uint8_t sharedSecret[64];
|
|
int ret = ecdh((uint8_t)pinUvAuthProtocol, &hkey.ctx.mbed_ecdh.Qp, sharedSecret);
|
|
if (ret != 0) {
|
|
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
|
|
CBOR_ERROR(CTAP1_ERR_INVALID_PARAMETER);
|
|
}
|
|
uint8_t pin_data[35];
|
|
memcpy(pin_data, file_get_data(ef_pin), file_get_size(ef_pin));
|
|
pin_data[0] -= 1;
|
|
file_put_data(ef_pin, pin_data, file_get_size(ef_pin));
|
|
low_flash_available();
|
|
uint8_t retries = pin_data[0];
|
|
uint8_t paddedNewPin[64], poff = ((uint8_t)pinUvAuthProtocol - 1) * IV_SIZE;
|
|
ret = decrypt((uint8_t)pinUvAuthProtocol, sharedSecret, pinHashEnc.data, (uint16_t)pinHashEnc.len, paddedNewPin);
|
|
if (ret != 0) {
|
|
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
|
|
CBOR_ERROR(CTAP2_ERR_PIN_AUTH_INVALID);
|
|
}
|
|
uint8_t dhash[32], off = 3;
|
|
if (file_get_size(ef_pin) == 34) {
|
|
off = 2;
|
|
double_hash_pin(paddedNewPin, 16, dhash);
|
|
}
|
|
else {
|
|
pin_derive_verifier(paddedNewPin, 16, dhash);
|
|
}
|
|
if (ct_memcmp(dhash, file_get_data(ef_pin) + off, 32) != 0) {
|
|
regenerate();
|
|
mbedtls_platform_zeroize(sharedSecret, sizeof(sharedSecret));
|
|
mbedtls_platform_zeroize(dhash, sizeof(dhash));
|
|
if (retries == 0) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_BLOCKED);
|
|
}
|
|
if (++new_pin_mismatches >= 3) {
|
|
needs_power_cycle = true;
|
|
CBOR_ERROR(CTAP2_ERR_PIN_AUTH_BLOCKED);
|
|
}
|
|
else {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_INVALID);
|
|
}
|
|
}
|
|
mbedtls_platform_zeroize(dhash, sizeof(dhash));
|
|
|
|
if (off == 2) {
|
|
// Upgrade pin file to new format
|
|
pin_data[2] = 1; // New format indicator
|
|
pin_derive_verifier(paddedNewPin, 16, pin_data + 3);
|
|
hash_multi(paddedNewPin, 16, session_pin);
|
|
ret = load_keydev(keydev);
|
|
if (ret != PICOKEY_OK) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_INVALID);
|
|
}
|
|
encrypt_keydev_f1(keydev);
|
|
}
|
|
|
|
pin_derive_session(paddedNewPin, 16, session_pin);
|
|
ret = check_keydev_encrypted(session_pin);
|
|
if (ret != PICOKEY_OK) {
|
|
CBOR_ERROR(ret);
|
|
}
|
|
|
|
pin_data[0] = MAX_PIN_RETRIES;
|
|
new_pin_mismatches = 0;
|
|
|
|
file_put_data(ef_pin, pin_data, sizeof(pin_data));
|
|
mbedtls_platform_zeroize(pin_data, sizeof(pin_data));
|
|
|
|
low_flash_available();
|
|
file_t *ef_minpin = search_by_fid(EF_MINPINLEN, NULL, SPECIFY_EF);
|
|
if (file_has_data(ef_minpin) && file_get_data(ef_minpin)[1] == 1) {
|
|
CBOR_ERROR(CTAP2_ERR_PIN_INVALID);
|
|
}
|
|
uint8_t pinUvAuthToken_enc[32 + IV_SIZE], *pdata = NULL;
|
|
if (permissions & CTAP_PERMISSION_PCMR) {
|
|
ppaut.permissions = CTAP_PERMISSION_PCMR;
|
|
pdata = ppaut.data;
|
|
}
|
|
else {
|
|
resetPinUvAuthToken();
|
|
beginUsingPinUvAuthToken(false);
|
|
if (subcommand == 0x05) {
|
|
permissions = CTAP_PERMISSION_MC | CTAP_PERMISSION_GA;
|
|
}
|
|
paut.permissions = (uint8_t)permissions;
|
|
if (rpId.present == true) {
|
|
mbedtls_sha256((uint8_t *) rpId.data, rpId.len, paut.rp_id_hash, 0);
|
|
paut.has_rp_id = true;
|
|
}
|
|
else {
|
|
paut.has_rp_id = false;
|
|
}
|
|
pdata = paut.data;
|
|
}
|
|
encrypt((uint8_t)pinUvAuthProtocol, sharedSecret, pdata, 32, pinUvAuthToken_enc);
|
|
CBOR_CHECK(cbor_encoder_create_map(&encoder, &mapEncoder, 1));
|
|
CBOR_CHECK(cbor_encode_uint(&mapEncoder, 0x02));
|
|
CBOR_CHECK(cbor_encode_byte_string(&mapEncoder, pinUvAuthToken_enc, 32 + poff));
|
|
}
|
|
else {
|
|
CBOR_ERROR(CTAP2_ERR_UNSUPPORTED_OPTION);
|
|
}
|
|
CBOR_CHECK(cbor_encoder_close_container(&encoder, &mapEncoder));
|
|
resp_size = cbor_encoder_get_buffer_size(&encoder, ctap_resp->init.data + 1);
|
|
err:
|
|
CBOR_FREE_BYTE_STRING(pinUvAuthParam);
|
|
CBOR_FREE_BYTE_STRING(newPinEnc);
|
|
CBOR_FREE_BYTE_STRING(pinHashEnc);
|
|
CBOR_FREE_BYTE_STRING(kax);
|
|
CBOR_FREE_BYTE_STRING(kay);
|
|
CBOR_FREE_BYTE_STRING(rpId);
|
|
mbedtls_platform_zeroize(keydev, sizeof(keydev));
|
|
if (error != CborNoError) {
|
|
if (error == CborErrorImproperValue) {
|
|
return CTAP2_ERR_CBOR_UNEXPECTED_TYPE;
|
|
}
|
|
return error;
|
|
}
|
|
res_APDU_size = (uint16_t)resp_size;
|
|
return 0;
|
|
}
|