mirror of
https://github.com/polhenarejos/pico-fido.git
synced 2025-12-18 09:30:04 +08:00
228 lines
8.7 KiB
C
228 lines
8.7 KiB
C
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/*
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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 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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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "ctap2_cbor.h"
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#include "cbor_make_credential.h"
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#include "fido.h"
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#include "ctap.h"
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#include "files.h"
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bool credential_verify(CborByteString *cred_id, const uint8_t *rp_id_hash) {
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if (cred_id->len < 4+12+16)
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return false;
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size_t cipher_len = cred_id->len - (4 + 12 + 16);
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uint8_t key[32], *iv = cred_id->data + 4, *cipher = cred_id->data + 4 + 12, *tag = cred_id->data - 16, *data = (uint8_t *)calloc(1, cipher_len);
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memset(key, 0, sizeof(key));
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mbedtls_chachapoly_context chatx;
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mbedtls_chachapoly_init(&chatx);
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mbedtls_chachapoly_setkey(&chatx, key);
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int ret = mbedtls_chachapoly_auth_decrypt(&chatx, cred_id->len - (4 + 12 + 16), iv, rp_id_hash, 32, tag, cipher, data);
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free(data);
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if (ret == 0)
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return true;
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return false;
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}
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int verify(CborByteString *clientDataHash, CborByteString *pinUvAuthParam) {
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return CborNoError;
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}
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int cbor_make_credential(const uint8_t *data, size_t len) {
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CborParser parser;
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CborValue map;
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CborError error = CborNoError;
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CborByteString clientDataHash = {0}, pinUvAuthParam = {0};
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PublicKeyCredentialRpEntity rp = {0};
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PublicKeyCredentialUserEntity user = {0};
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PublicKeyCredentialParameters pubKeyCredParams[16] = {0};
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size_t pubKeyCredParams_len = 0;
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PublicKeyCredentialDescriptor excludeList[16] = {0};
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size_t excludeList_len = 0;
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CredOptions options = {0};
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uint64_t pinUvAuthProtocol = 0, enterpriseAttestation = 0;
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CBOR_CHECK(cbor_parser_init(data, len, 0, &parser, &map));
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CBOR_PARSE_MAP_START(map, 1) {
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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_u == 0x01) { // clientDataHash
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CBOR_FIELD_GET_BYTES(clientDataHash, 1);
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}
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else if (val_u == 0x02) { // rp
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CBOR_PARSE_MAP_START(_f1, 2) {
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CBOR_FIELD_GET_KEY_TEXT(2);
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CBOR_FIELD_KEY_TEXT_VAL_TEXT(2, "id", rp.id);
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CBOR_FIELD_KEY_TEXT_VAL_TEXT(2, "name", rp.parent.name);
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}
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CBOR_PARSE_MAP_END(_f1, 2);
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}
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else if (val_u == 0x03) { // user
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CBOR_PARSE_MAP_START(_f1, 2) {
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CBOR_FIELD_GET_KEY_TEXT(2);
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CBOR_FIELD_KEY_TEXT_VAL_BYTES(2, "id", user.id);
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CBOR_FIELD_KEY_TEXT_VAL_TEXT(2, "name", user.parent.name);
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CBOR_FIELD_KEY_TEXT_VAL_TEXT(2, "displayName", user.displayName);
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}
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CBOR_PARSE_MAP_END(_f1, 2);
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}
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else if (val_u == 0x04) { // pubKeyCredParams
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CBOR_PARSE_ARRAY_START(_f1, 2) {
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PublicKeyCredentialParameters *pk = &pubKeyCredParams[pubKeyCredParams_len];
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CBOR_PARSE_MAP_START(_f2, 3) {
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CBOR_FIELD_GET_KEY_TEXT(3);
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CBOR_FIELD_KEY_TEXT_VAL_TEXT(3, "type", pk->type);
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CBOR_FIELD_KEY_TEXT_VAL_INT(3, "alg", pk->alg);
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}
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CBOR_PARSE_MAP_END(_f2, 3);
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pubKeyCredParams_len++;
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}
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CBOR_PARSE_ARRAY_END(_f1, 2);
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}
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else if (val_u == 0x05) { // excludeList
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CBOR_PARSE_ARRAY_START(_f1, 2) {
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PublicKeyCredentialDescriptor *pc = &excludeList[excludeList_len];
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CBOR_PARSE_MAP_START(_f1, 3) {
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CBOR_FIELD_GET_KEY_TEXT(3);
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CBOR_FIELD_KEY_TEXT_VAL_BYTES(3, "id", pc->id);
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CBOR_FIELD_KEY_TEXT_VAL_TEXT(3, "type", pc->type);
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if (strcmp(_fd3, "transports") == 0) {
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CBOR_PARSE_ARRAY_START(_f2, 4) {
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CBOR_FIELD_GET_TEXT(pc->transports[pc->transports_len], 4);
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pc->transports_len++;
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}
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CBOR_PARSE_ARRAY_END(_f2, 4);
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}
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}
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CBOR_PARSE_MAP_END(_f1, 3);
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excludeList_len++;
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}
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CBOR_PARSE_ARRAY_END(_f1, 2);
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}
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else if (val_u == 0x06) { // extensions
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CBOR_ADVANCE(1);
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}
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else if (val_u == 0x07) { // options
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options.present = true;
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CBOR_PARSE_MAP_START(_f1, 2) {
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CBOR_FIELD_GET_KEY_TEXT(2);
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CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "rk", options.rk);
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CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "up", options.up);
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CBOR_FIELD_KEY_TEXT_VAL_BOOL(2, "uv", options.uv);
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}
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CBOR_PARSE_MAP_END(_f1, 2);
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}
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else if (val_u == 0x08) { // pinUvAuthParam
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CBOR_FIELD_GET_BYTES(pinUvAuthParam, 1);
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}
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else if (val_u == 0x09) { // pinUvAuthProtocol
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CBOR_FIELD_GET_UINT(pinUvAuthProtocol, 1);
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}
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else if (val_u == 0x0A) { // enterpriseAttestation
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CBOR_FIELD_GET_UINT(enterpriseAttestation, 1);
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}
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}
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CBOR_PARSE_MAP_END(map, 1);
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uint8_t rp_id_hash[32];
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mbedtls_sha256((uint8_t *)rp.id.data, rp.id.len, rp_id_hash, 0);
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for (int i = 0; i < pubKeyCredParams_len; i++) {
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if (strcmp(pubKeyCredParams[i].type.data, "public-key") != 0)
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continue;
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if (pubKeyCredParams[i].alg != FIDO2_ALG_ES256 && pubKeyCredParams[i].alg != FIDO2_ALG_ES384 && pubKeyCredParams[i].alg != FIDO2_ALG_ES512)
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CBOR_ERROR(CTAP2_ERR_UNSUPPORTED_ALGORITHM);
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}
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if (pinUvAuthParam.len == 0 || pinUvAuthParam.data == NULL) {
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if (wait_button_pressed() == true)
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CBOR_ERROR(CTAP2_ERR_OPERATION_DENIED);
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if (!file_has_data(ef_pin))
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CBOR_ERROR(CTAP2_ERR_PIN_NOT_SET);
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else
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CBOR_ERROR(CTAP2_ERR_PIN_INVALID);
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}
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else if (pinUvAuthParam.present == true) {
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if (pinUvAuthProtocol == 0)
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CBOR_ERROR(CTAP2_ERR_MISSING_PARAMETER);
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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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bool *rup = pfalse;
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if (options.present) {
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if (options.uv == ptrue) { //5.3
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CBOR_ERROR(CTAP2_ERR_INVALID_OPTION);
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}
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if (options.up == pfalse) { //5.6
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CBOR_ERROR(CTAP2_ERR_INVALID_OPTION);
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}
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else if (options.up == NULL) //5.7
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rup = ptrue;
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}
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if (pinUvAuthParam.present == false && options.uv == pfalse && file_has_data(ef_pin)) { //8.1
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CBOR_ERROR(CTAP2_ERR_PUAT_REQUIRED);
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}
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if (enterpriseAttestation > 0) {
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if (enterpriseAttestation != 1 && enterpriseAttestation != 2) { //9.2.1
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CBOR_ERROR(CTAP2_ERR_INVALID_OPTION);
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}
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//Unfinished. See 6.1.2.9
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}
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if (pinUvAuthParam.present == true) { //11.1
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int ret = verify(&clientDataHash, &pinUvAuthParam);
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if (ret != CborNoError)
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CBOR_ERROR(CTAP2_ERR_PIN_AUTH_INVALID);
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//Check pinUvAuthToken permissions. See 6.1.2.11
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}
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for (int e = 0; e < excludeList_len; e++) { //12.1
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if (strcmp(excludeList[e].type.data, "public-key") != 0)
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continue;
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if (credential_verify(&excludeList[e].id, rp_id_hash) == true)
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CBOR_ERROR(CTAP2_ERR_CREDENTIAL_EXCLUDED);
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}
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if (pinUvAuthParam.present && options.up == ptrue) { //14.1
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if (wait_button_pressed() == true)
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CBOR_ERROR(CTAP2_ERR_OPERATION_DENIED);
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rup = ptrue;
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}
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err:
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CBOR_FREE_BYTE_STRING(clientDataHash);
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CBOR_FREE_BYTE_STRING(pinUvAuthParam);
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CBOR_FREE_BYTE_STRING(rp.id);
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CBOR_FREE_BYTE_STRING(rp.parent.name);
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CBOR_FREE_BYTE_STRING(user.id);
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CBOR_FREE_BYTE_STRING(user.displayName);
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CBOR_FREE_BYTE_STRING(user.parent.name);
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for (int n = 0; n < pubKeyCredParams_len; n++) {
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CBOR_FREE_BYTE_STRING(pubKeyCredParams[n].type);
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}
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for (int m = 0; m < excludeList_len; m++) {
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CBOR_FREE_BYTE_STRING(excludeList[m].type);
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CBOR_FREE_BYTE_STRING(excludeList[m].id);
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for (int n = 0; n < excludeList[m].transports_len; n++) {
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CBOR_FREE_BYTE_STRING(excludeList[m].transports[n]);
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}
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}
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if (error != CborNoError)
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return -CTAP2_ERR_INVALID_CBOR;
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driver_exec_finished(1);
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return 0;
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}
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