Files
pico-fido/src/fido/cbor.c
Pol Henarejos 1867f0330f Move EDDSA to another branch.
Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
2025-12-09 15:56:31 +01:00

260 lines
8.7 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 Affero 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
* Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "pico_keys.h"
#if defined(PICO_PLATFORM)
#include "pico/stdlib.h"
#endif
#include "hid/ctap_hid.h"
#include "ctap.h"
#include "fido.h"
#include "usb.h"
#include "apdu.h"
#include "management.h"
#include "ctap2_cbor.h"
#include "version.h"
const bool _btrue = true, _bfalse = false;
int cbor_reset();
int cbor_get_info();
int cbor_make_credential(const uint8_t *data, size_t len);
int cbor_client_pin(const uint8_t *data, size_t len);
int cbor_get_assertion(const uint8_t *data, size_t len, bool next);
int cbor_get_next_assertion(const uint8_t *data, size_t len);
int cbor_selection();
int cbor_cred_mgmt(const uint8_t *data, size_t len);
int cbor_config(const uint8_t *data, size_t len);
int cbor_vendor(const uint8_t *data, size_t len);
int cbor_large_blobs(const uint8_t *data, size_t len);
extern int cmd_read_config();
const uint8_t aaguid[16] = { 0x89, 0xFB, 0x94, 0xB7, 0x06, 0xC9, 0x36, 0x73, 0x9B, 0x7E, 0x30, 0x52, 0x6D, 0x96, 0x81, 0x45 }; // First 16 bytes of SHA256("Pico FIDO2")
const uint8_t *cbor_data = NULL;
size_t cbor_len = 0;
uint8_t cbor_cmd = 0;
int cbor_parse(uint8_t cmd, const uint8_t *data, size_t len) {
if (len == 0 && cmd == CTAPHID_CBOR) {
return CTAP1_ERR_INVALID_LEN;
}
if (len > 0) {
DEBUG_DATA(data + 1, len - 1);
}
if (cap_supported(CAP_FIDO2)) {
if (cmd == CTAPHID_CBOR) {
if (data[0] == CTAP_MAKE_CREDENTIAL) {
return cbor_make_credential(data + 1, len - 1);
}
if (data[0] == CTAP_GET_INFO) {
return cbor_get_info();
}
else if (data[0] == CTAP_RESET) {
return cbor_reset();
}
else if (data[0] == CTAP_CLIENT_PIN) {
return cbor_client_pin(data + 1, len - 1);
}
else if (data[0] == CTAP_GET_ASSERTION) {
return cbor_get_assertion(data + 1, len - 1, false);
}
else if (data[0] == CTAP_GET_NEXT_ASSERTION) {
return cbor_get_next_assertion(data + 1, len - 1);
}
else if (data[0] == CTAP_SELECTION) {
return cbor_selection();
}
else if (data[0] == CTAP_CREDENTIAL_MGMT || data[0] == 0x41) {
return cbor_cred_mgmt(data + 1, len - 1);
}
else if (data[0] == CTAP_CONFIG) {
return cbor_config(data + 1, len - 1);
}
else if (data[0] == CTAP_LARGE_BLOBS) {
return cbor_large_blobs(data + 1, len - 1);
}
}
else if (cmd == CTAP_VENDOR_CBOR) {
return cbor_vendor(data, len);
}
else if (cmd == 0xC2) {
if (cmd_read_config() == 0x9000) {
memmove(res_APDU-1, res_APDU, res_APDU_size);
res_APDU_size -= 1;
return 0;
}
}
}
return CTAP1_ERR_INVALID_CMD;
}
void *cbor_thread(void *arg) {
(void)arg;
card_init_core1();
while (1) {
uint32_t m;
queue_remove_blocking(&usb_to_card_q, &m);
uint32_t flag = m + 1;
queue_add_blocking(&card_to_usb_q, &flag);
if (m == EV_EXIT) {
break;
}
apdu.sw = (uint16_t)cbor_parse(cbor_cmd, cbor_data, cbor_len);
if (apdu.sw == 0) {
DEBUG_DATA(res_APDU, res_APDU_size);
}
else {
if (apdu.sw >= CTAP1_ERR_INVALID_CHANNEL) {
res_APDU[-1] = (uint8_t)apdu.sw;
apdu.sw = 0;
}
else {
res_APDU[0] = (uint8_t)apdu.sw;
}
}
finished_data_size = res_APDU_size + 1;
flag = EV_EXEC_FINISHED;
queue_add_blocking(&card_to_usb_q, &flag);
}
return NULL;
}
int cbor_process(uint8_t last_cmd, const uint8_t *data, size_t len) {
cbor_data = data;
cbor_len = len;
cbor_cmd = last_cmd;
ctap_resp->init.data[0] = 0;
res_APDU = ctap_resp->init.data + 1;
res_APDU_size = 0;
return 2; // CBOR processing
}
CborError COSE_key_params(int crv, int alg, mbedtls_ecp_group *grp, mbedtls_ecp_point *Q, CborEncoder *mapEncoderParent, CborEncoder *mapEncoder) {
CborError error = CborNoError;
int kty = 1;
if (crv == FIDO2_CURVE_P256 || crv == FIDO2_CURVE_P384 || crv == FIDO2_CURVE_P521 ||
crv == FIDO2_CURVE_P256K1) {
kty = 2;
}
CBOR_CHECK(cbor_encoder_create_map(mapEncoderParent, mapEncoder, kty == 2 ? 5 : 4));
CBOR_CHECK(cbor_encode_uint(mapEncoder, 1));
CBOR_CHECK(cbor_encode_uint(mapEncoder, kty));
CBOR_CHECK(cbor_encode_uint(mapEncoder, 3));
CBOR_CHECK(cbor_encode_negative_int(mapEncoder, -alg));
CBOR_CHECK(cbor_encode_negative_int(mapEncoder, 1));
CBOR_CHECK(cbor_encode_uint(mapEncoder, crv));
CBOR_CHECK(cbor_encode_negative_int(mapEncoder, 2));
uint8_t pkey[67];
if (kty == 2) {
size_t plen = mbedtls_mpi_size(&grp->P);
CBOR_CHECK(mbedtls_mpi_write_binary(&Q->X, pkey, plen));
CBOR_CHECK(cbor_encode_byte_string(mapEncoder, pkey, plen));
CBOR_CHECK(cbor_encode_negative_int(mapEncoder, 3));
CBOR_CHECK(mbedtls_mpi_write_binary(&Q->Y, pkey, plen));
CBOR_CHECK(cbor_encode_byte_string(mapEncoder, pkey, plen));
}
else {
size_t olen = 0;
CBOR_CHECK(mbedtls_ecp_point_write_binary(grp, Q, MBEDTLS_ECP_PF_COMPRESSED, &olen, pkey,
sizeof(pkey)));
CBOR_CHECK(cbor_encode_byte_string(mapEncoder, pkey, olen));
}
CBOR_CHECK(cbor_encoder_close_container(mapEncoderParent, mapEncoder));
err:
return error;
}
CborError COSE_key(mbedtls_ecp_keypair *key, CborEncoder *mapEncoderParent,
CborEncoder *mapEncoder) {
int crv = mbedtls_curve_to_fido(key->grp.id), alg = 0;
if (key->grp.id == MBEDTLS_ECP_DP_SECP256R1) {
alg = FIDO2_ALG_ES256;
}
else if (key->grp.id == MBEDTLS_ECP_DP_SECP384R1) {
alg = FIDO2_ALG_ES384;
}
else if (key->grp.id == MBEDTLS_ECP_DP_SECP521R1) {
alg = FIDO2_ALG_ES512;
}
else if (key->grp.id == MBEDTLS_ECP_DP_SECP256K1) {
alg = FIDO2_ALG_ES256K;
}
else if (key->grp.id == MBEDTLS_ECP_DP_CURVE25519) {
alg = FIDO2_ALG_ECDH_ES_HKDF_256;
}
return COSE_key_params(crv, alg, &key->grp, &key->Q, mapEncoderParent, mapEncoder);
}
CborError COSE_key_shared(mbedtls_ecdh_context *key,
CborEncoder *mapEncoderParent,
CborEncoder *mapEncoder) {
int crv = mbedtls_curve_to_fido(key->ctx.mbed_ecdh.grp.id), alg = FIDO2_ALG_ECDH_ES_HKDF_256;
return COSE_key_params(crv, alg, &key->ctx.mbed_ecdh.grp, &key->ctx.mbed_ecdh.Q, mapEncoderParent, mapEncoder);
}
CborError COSE_public_key(int alg, CborEncoder *mapEncoderParent, CborEncoder *mapEncoder) {
CborError error = CborNoError;
CBOR_CHECK(cbor_encoder_create_map(mapEncoderParent, mapEncoder, 2));
CBOR_CHECK(cbor_encode_text_stringz(mapEncoder, "alg"));
CBOR_CHECK(cbor_encode_negative_int(mapEncoder, -alg));
CBOR_CHECK(cbor_encode_text_stringz(mapEncoder, "type"));
CBOR_CHECK(cbor_encode_text_stringz(mapEncoder, "public-key"));
CBOR_CHECK(cbor_encoder_close_container(mapEncoderParent, mapEncoder));
err:
return error;
}
CborError COSE_read_key(CborValue *f, int64_t *kty, int64_t *alg, int64_t *crv, CborByteString *kax, CborByteString *kay) {
int64_t kkey = 0;
CborError error = CborNoError;
CBOR_PARSE_MAP_START(*f, 0)
{
CBOR_FIELD_GET_INT(kkey, 0);
if (kkey == 1) {
CBOR_FIELD_GET_INT(*kty, 0);
}
else if (kkey == 3) {
CBOR_FIELD_GET_INT(*alg, 0);
}
else if (kkey == -1) {
CBOR_FIELD_GET_INT(*crv, 0);
}
else if (kkey == -2) {
CBOR_FIELD_GET_BYTES(*kax, 0);
}
else if (kkey == -3) {
CBOR_FIELD_GET_BYTES(*kay, 0);
}
else {
CBOR_ADVANCE(0);
}
}
CBOR_PARSE_MAP_END(*f, 0);
err:
return error;
}