mirror of
https://github.com/polhenarejos/pico-fido
synced 2026-05-28 00:41:18 +02:00
75 lines
3.3 KiB
C
75 lines
3.3 KiB
C
/*
|
|
* This file is part of the Pico FIDO distribution (https://github.com/polhenarejos/pico-fido).
|
|
* Copyright (c) 2022 Pol Henarejos.
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, version 3.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "fido.h"
|
|
#include "hsm.h"
|
|
#include "apdu.h"
|
|
#include "ctap.h"
|
|
#include "mbedtls/ecdsa.h"
|
|
#include "random.h"
|
|
#include "files.h"
|
|
|
|
int cmd_register() {
|
|
CTAP_REGISTER_REQ *req = (CTAP_REGISTER_REQ *)apdu.data;
|
|
CTAP_REGISTER_RESP *resp = (CTAP_REGISTER_RESP *)res_APDU;
|
|
resp->registerId = CTAP_REGISTER_ID;
|
|
resp->keyHandleLen = KEY_HANDLE_LEN;
|
|
if (scan_files() != CCID_OK)
|
|
return SW_EXEC_ERROR();
|
|
if (apdu.nc != CTAP_APPID_SIZE + CTAP_CHAL_SIZE)
|
|
return SW_WRONG_LENGTH();
|
|
if (wait_button_pressed() == true)
|
|
return SW_CONDITIONS_NOT_SATISFIED();
|
|
mbedtls_ecdsa_context key;
|
|
mbedtls_ecdsa_init(&key);
|
|
int ret = derive_key(req->appId, true, resp->keyHandleCertSig, MBEDTLS_ECP_DP_SECP256R1, &key);
|
|
if (ret != CCID_OK) {
|
|
mbedtls_ecdsa_free(&key);
|
|
return SW_EXEC_ERROR();
|
|
}
|
|
size_t olen = 0;
|
|
ret = mbedtls_ecp_point_write_binary(&key.grp, &key.Q, MBEDTLS_ECP_PF_UNCOMPRESSED, &olen, (uint8_t *)&resp->pubKey, CTAP_EC_POINT_SIZE);
|
|
mbedtls_ecdsa_free(&key);
|
|
if (ret != 0) {
|
|
return SW_EXEC_ERROR();
|
|
}
|
|
size_t ef_certdev_size = file_get_size(ef_certdev);
|
|
memcpy(resp->keyHandleCertSig + KEY_HANDLE_LEN, file_get_data(ef_certdev), ef_certdev_size);
|
|
uint8_t hash[32], sign_base[1 + CTAP_APPID_SIZE + CTAP_CHAL_SIZE + KEY_HANDLE_LEN + CTAP_EC_POINT_SIZE];
|
|
sign_base[0] = CTAP_REGISTER_HASH_ID;
|
|
memcpy(sign_base + 1, req->appId, CTAP_APPID_SIZE);
|
|
memcpy(sign_base + 1 + CTAP_APPID_SIZE, req->chal, CTAP_CHAL_SIZE);
|
|
memcpy(sign_base + 1 + CTAP_APPID_SIZE + CTAP_CHAL_SIZE, resp->keyHandleCertSig, KEY_HANDLE_LEN);
|
|
memcpy(sign_base + 1 + CTAP_APPID_SIZE + CTAP_CHAL_SIZE + KEY_HANDLE_LEN, (uint8_t *)&resp->pubKey, CTAP_EC_POINT_SIZE);
|
|
ret = mbedtls_md(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), sign_base, sizeof(sign_base), hash);
|
|
if (ret != 0)
|
|
return SW_EXEC_ERROR();
|
|
mbedtls_ecdsa_init(&key);
|
|
ret = mbedtls_ecp_read_key(MBEDTLS_ECP_DP_SECP256R1, &key, file_get_data(ef_keydev), 32);
|
|
if (ret != CCID_OK) {
|
|
mbedtls_ecdsa_free(&key);
|
|
return SW_EXEC_ERROR();
|
|
}
|
|
ret = mbedtls_ecdsa_write_signature(&key, MBEDTLS_MD_SHA256, hash, 32, (uint8_t *)resp->keyHandleCertSig + KEY_HANDLE_LEN + ef_certdev_size, CTAP_MAX_EC_SIG_SIZE, &olen, random_gen, NULL);
|
|
mbedtls_ecdsa_free(&key);
|
|
if (ret != 0)
|
|
return SW_EXEC_ERROR();
|
|
res_APDU_size = sizeof(CTAP_REGISTER_RESP) - sizeof(resp->keyHandleCertSig) + KEY_HANDLE_LEN + ef_certdev_size + olen;
|
|
DEBUG_PAYLOAD(res_APDU, res_APDU_size);
|
|
return SW_OK();
|
|
}
|