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trezor-firmware/core/embed/prodtest/optiga_prodtest.c
2023-09-27 17:17:09 +02:00

497 lines
15 KiB
C

/*
* This file is part of the Trezor project, https://trezor.io/
*
* Copyright (c) SatoshiLabs
*
* 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, either version 3 of the License, or
* (at your option) any later version.
*
* 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 "optiga_prodtest.h"
#include "aes/aes.h"
#include "ecdsa.h"
#include "memzero.h"
#include "nist256p1.h"
#include "optiga_commands.h"
#include "optiga_transport.h"
#include "prodtest_common.h"
#include "rand.h"
#include "secret.h"
#include "sha2.h"
typedef enum {
OPTIGA_PAIRING_UNPAIRED = 0,
OPTIGA_PAIRING_PAIRED,
OPTIGA_PAIRING_ERR_RNG,
OPTIGA_PAIRING_ERR_READ,
OPTIGA_PAIRING_ERR_HANDSHAKE,
} optiga_pairing;
static optiga_pairing optiga_pairing_state = OPTIGA_PAIRING_UNPAIRED;
// Data object access conditions.
static const optiga_metadata_item ACCESS_PAIRED =
OPTIGA_ACCESS_CONDITION(OPTIGA_ACCESS_COND_CONF, OID_KEY_PAIRING);
static const optiga_metadata_item KEY_USE_SIGN = {
(const uint8_t[]){OPTIGA_KEY_USAGE_SIGN}, 1};
static const optiga_metadata_item TYPE_PTFBIND = {
(const uint8_t[]){OPTIGA_DATA_TYPE_PTFBIND}, 1};
static bool optiga_paired(void) {
const char *details = "";
switch (optiga_pairing_state) {
case OPTIGA_PAIRING_PAIRED:
return true;
case OPTIGA_PAIRING_ERR_RNG:
details = "optiga_get_random error";
break;
case OPTIGA_PAIRING_ERR_READ:
details = "failed to read pairing secret";
break;
case OPTIGA_PAIRING_ERR_HANDSHAKE:
details = "optiga_sec_chan_handshake";
break;
default:
break;
}
vcp_println("ERROR Optiga not paired (%s).", details);
return false;
}
static bool set_metadata(uint16_t oid, const optiga_metadata *metadata) {
uint8_t serialized[OPTIGA_MAX_METADATA_SIZE] = {0};
size_t size = 0;
optiga_result ret = optiga_serialize_metadata(metadata, serialized,
sizeof(serialized), &size);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_serialize_metadata error %d for OID 0x%04x.", ret,
oid);
return false;
}
optiga_set_data_object(oid, true, serialized, size);
ret =
optiga_get_data_object(oid, true, serialized, sizeof(serialized), &size);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_get_metadata error %d for OID 0x%04x.", ret, oid);
return false;
}
optiga_metadata metadata_stored = {0};
ret = optiga_parse_metadata(serialized, size, &metadata_stored);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_parse_metadata error %d.", ret);
return false;
}
if (!optiga_compare_metadata(metadata, &metadata_stored)) {
vcp_println("ERROR optiga_compare_metadata failed.");
return false;
}
return true;
}
void pair_optiga(void) {
// The pairing key may already be written and locked. The success of the
// pairing procedure is determined by optiga_sec_chan_handshake(). Therefore
// it is OK for some of the intermediate operations to fail.
// Enable writing the pairing secret to OPTIGA.
optiga_metadata metadata = {0};
metadata.change = OPTIGA_META_ACCESS_ALWAYS;
metadata.execute = OPTIGA_META_ACCESS_ALWAYS;
metadata.data_type = TYPE_PTFBIND;
set_metadata(OID_KEY_PAIRING, &metadata); // Ignore result.
// Generate pairing secret.
uint8_t secret[SECRET_OPTIGA_KEY_LEN] = {0};
optiga_result ret = optiga_get_random(secret, sizeof(secret));
if (OPTIGA_SUCCESS != ret) {
optiga_pairing_state = OPTIGA_PAIRING_ERR_RNG;
return;
}
// Store pairing secret.
ret = optiga_set_data_object(OID_KEY_PAIRING, false, secret, sizeof(secret));
if (OPTIGA_SUCCESS == ret) {
secret_erase();
secret_write_header();
secret_write(secret, SECRET_OPTIGA_KEY_OFFSET, SECRET_OPTIGA_KEY_LEN);
}
// Verify whether the secret was stored correctly in flash and OPTIGA.
memzero(secret, sizeof(secret));
if (secret_read(secret, SECRET_OPTIGA_KEY_OFFSET, SECRET_OPTIGA_KEY_LEN) !=
sectrue) {
optiga_pairing_state = OPTIGA_PAIRING_ERR_READ;
return;
}
ret = optiga_sec_chan_handshake(secret, sizeof(secret));
memzero(secret, sizeof(secret));
if (OPTIGA_SUCCESS != ret) {
optiga_pairing_state = OPTIGA_PAIRING_ERR_HANDSHAKE;
return;
}
optiga_pairing_state = OPTIGA_PAIRING_PAIRED;
return;
}
void optiga_lock(void) {
if (!optiga_paired()) return;
// Delete trust anchor.
optiga_result ret =
optiga_set_data_object(OID_TRUST_ANCHOR, false, (const uint8_t *)"\0", 1);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_set_data error %d for 0x%04x.", ret,
OID_TRUST_ANCHOR);
return;
}
// Set data object metadata.
optiga_metadata metadata = {0};
// Set metadata for device certificate.
memzero(&metadata, sizeof(metadata));
metadata.lcso = OPTIGA_META_LCS_OPERATIONAL;
metadata.change = OPTIGA_META_ACCESS_NEVER;
metadata.read = OPTIGA_META_ACCESS_ALWAYS;
metadata.execute = OPTIGA_META_ACCESS_ALWAYS;
if (!set_metadata(OID_CERT_DEV, &metadata)) {
return;
}
// Set metadata for FIDO attestation certificate.
memzero(&metadata, sizeof(metadata));
metadata.lcso = OPTIGA_META_LCS_OPERATIONAL;
metadata.change = OPTIGA_META_ACCESS_NEVER;
metadata.read = OPTIGA_META_ACCESS_ALWAYS;
metadata.execute = OPTIGA_META_ACCESS_ALWAYS;
if (!set_metadata(OID_CERT_FIDO, &metadata)) {
return;
}
// Set metadata for device private key.
memzero(&metadata, sizeof(metadata));
metadata.lcso = OPTIGA_META_LCS_OPERATIONAL;
metadata.change = OPTIGA_META_ACCESS_NEVER;
metadata.read = OPTIGA_META_ACCESS_NEVER;
metadata.execute = ACCESS_PAIRED;
metadata.key_usage = KEY_USE_SIGN;
if (!set_metadata(OID_KEY_DEV, &metadata)) {
return;
}
// Set metadata for FIDO attestation private key.
memzero(&metadata, sizeof(metadata));
metadata.lcso = OPTIGA_META_LCS_OPERATIONAL;
metadata.change = OPTIGA_META_ACCESS_NEVER;
metadata.read = OPTIGA_META_ACCESS_NEVER;
metadata.execute = ACCESS_PAIRED;
metadata.key_usage = KEY_USE_SIGN;
if (!set_metadata(OID_KEY_FIDO, &metadata)) {
return;
}
// Set metadata for pairing key.
memzero(&metadata, sizeof(metadata));
metadata.lcso = OPTIGA_META_LCS_OPERATIONAL;
metadata.change = OPTIGA_META_ACCESS_NEVER;
metadata.read = OPTIGA_META_ACCESS_NEVER;
metadata.execute = OPTIGA_META_ACCESS_ALWAYS;
metadata.data_type = TYPE_PTFBIND;
if (!set_metadata(OID_KEY_PAIRING, &metadata)) {
return;
}
vcp_println("OK");
}
optiga_locked_status get_optiga_locked_status(void) {
if (!optiga_paired()) return OPTIGA_LOCKED_ERROR;
const uint16_t oids[] = {OID_CERT_DEV, OID_CERT_FIDO, OID_KEY_DEV,
OID_KEY_FIDO, OID_KEY_PAIRING};
optiga_metadata locked_metadata = {0};
locked_metadata.lcso = OPTIGA_META_LCS_OPERATIONAL;
for (size_t i = 0; i < sizeof(oids) / sizeof(oids[0]); ++i) {
uint8_t metadata_buffer[OPTIGA_MAX_METADATA_SIZE] = {0};
size_t metadata_size = 0;
optiga_result ret =
optiga_get_data_object(oids[i], true, metadata_buffer,
sizeof(metadata_buffer), &metadata_size);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_get_metadata error %d for OID 0x%04x.", ret,
oids[i]);
return OPTIGA_LOCKED_ERROR;
}
optiga_metadata stored_metadata = {0};
ret =
optiga_parse_metadata(metadata_buffer, metadata_size, &stored_metadata);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_parse_metadata error %d.", ret);
return OPTIGA_LOCKED_ERROR;
}
if (!optiga_compare_metadata(&locked_metadata, &stored_metadata)) {
return OPTIGA_LOCKED_FALSE;
}
}
return OPTIGA_LOCKED_TRUE;
}
void check_locked(void) {
switch (get_optiga_locked_status()) {
case OPTIGA_LOCKED_TRUE:
vcp_println("OK YES");
break;
case OPTIGA_LOCKED_FALSE:
vcp_println("OK NO");
break;
default:
// Error reported by get_optiga_locked_status().
break;
}
}
void optigaid_read(void) {
if (!optiga_paired()) return;
uint8_t optiga_id[27] = {0};
size_t optiga_id_size = 0;
optiga_result ret =
optiga_get_data_object(OPTIGA_OID_COPROC_UID, false, optiga_id,
sizeof(optiga_id), &optiga_id_size);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_get_data_object error %d for 0x%04x.", ret,
OPTIGA_OID_COPROC_UID);
return;
}
vcp_print("OK ");
vcp_println_hex(optiga_id, optiga_id_size);
}
void cert_read(uint16_t oid) {
if (!optiga_paired()) return;
static uint8_t cert[2048] = {0};
size_t cert_size = 0;
optiga_result ret =
optiga_get_data_object(oid, false, cert, sizeof(cert), &cert_size);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_get_data_object error %d for 0x%04x.", ret, oid);
return;
}
size_t offset = 0;
if (cert[0] == 0xC0) {
// TLS identity certificate chain.
size_t tls_identity_size = (cert[1] << 8) + cert[2];
size_t cert_chain_size = (cert[3] << 16) + (cert[4] << 8) + cert[5];
size_t first_cert_size = (cert[6] << 16) + (cert[7] << 8) + cert[8];
if (tls_identity_size + 3 > cert_size ||
cert_chain_size + 3 > tls_identity_size ||
first_cert_size > cert_chain_size) {
vcp_println("ERROR invalid TLS identity in 0x%04x.", oid);
return;
}
offset = 9;
cert_size = first_cert_size;
}
if (cert_size == 0) {
vcp_println("ERROR no certificate in 0x%04x.", oid);
return;
}
vcp_print("OK ");
vcp_println_hex(cert + offset, cert_size);
}
void cert_write(uint16_t oid, char *data) {
if (!optiga_paired()) return;
// Enable writing to the certificate slot.
optiga_metadata metadata = {0};
metadata.change = OPTIGA_META_ACCESS_ALWAYS;
set_metadata(oid, &metadata); // Ignore result.
uint8_t data_bytes[1024];
int len = get_from_hex(data_bytes, sizeof(data_bytes), data);
if (len < 0) {
vcp_println("ERROR Hexadecimal decoding error %d.", len);
return;
}
optiga_result ret = optiga_set_data_object(oid, false, data_bytes, len);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_set_data error %d for 0x%04x.", ret, oid);
return;
}
vcp_println("OK");
}
void pubkey_read(uint16_t oid) {
if (!optiga_paired()) return;
// Enable key agreement usage.
optiga_metadata metadata = {0};
metadata.key_usage = OPTIGA_META_KEY_USE_KEYAGREE;
metadata.execute = OPTIGA_META_ACCESS_ALWAYS;
if (!set_metadata(oid, &metadata)) {
return;
}
// Execute ECDH with base point to get the x-coordinate of the public key.
static const uint8_t BASE_POINT[] = {
0x03, 0x42, 0x00, 0x04, 0x6b, 0x17, 0xd1, 0xf2, 0xe1, 0x2c, 0x42, 0x47,
0xf8, 0xbc, 0xe6, 0xe5, 0x63, 0xa4, 0x40, 0xf2, 0x77, 0x03, 0x7d, 0x81,
0x2d, 0xeb, 0x33, 0xa0, 0xf4, 0xa1, 0x39, 0x45, 0xd8, 0x98, 0xc2, 0x96,
0x4f, 0xe3, 0x42, 0xe2, 0xfe, 0x1a, 0x7f, 0x9b, 0x8e, 0xe7, 0xeb, 0x4a,
0x7c, 0x0f, 0x9e, 0x16, 0x2b, 0xce, 0x33, 0x57, 0x6b, 0x31, 0x5e, 0xce,
0xcb, 0xb6, 0x40, 0x68, 0x37, 0xbf, 0x51, 0xf5};
uint8_t public_key[32] = {0};
size_t public_key_size = 0;
optiga_result ret =
optiga_calc_ssec(OPTIGA_CURVE_P256, oid, BASE_POINT, sizeof(BASE_POINT),
public_key, sizeof(public_key), &public_key_size);
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_calc_ssec error %d.", ret);
return;
}
vcp_print("OK ");
vcp_println_hex(public_key, public_key_size);
}
void keyfido_write(char *data) {
if (!optiga_paired()) return;
const size_t EPH_PUB_KEY_SIZE = 33;
const size_t PAYLOAD_SIZE = 32;
const size_t CIPHERTEXT_OFFSET = EPH_PUB_KEY_SIZE;
const size_t EXPECTED_SIZE = EPH_PUB_KEY_SIZE + PAYLOAD_SIZE;
// Enable key agreement usage for device key.
optiga_metadata metadata = {0};
metadata.key_usage = OPTIGA_META_KEY_USE_KEYAGREE;
metadata.execute = OPTIGA_META_ACCESS_ALWAYS;
if (!set_metadata(OID_KEY_DEV, &metadata)) {
return;
}
// Read encrypted FIDO attestation private key.
uint8_t data_bytes[EXPECTED_SIZE];
int len = get_from_hex(data_bytes, sizeof(data_bytes), data);
if (len < 0) {
vcp_println("ERROR Hexadecimal decoding error %d.", len);
return;
}
if (len != EXPECTED_SIZE) {
vcp_println("ERROR Unexpected input length.");
return;
}
// Expand sender's ephemeral public key.
uint8_t public_key[3 + 65] = {0x03, 0x42, 0x00};
if (ecdsa_uncompress_pubkey(&nist256p1, data_bytes, &public_key[3]) != 1) {
vcp_println("ERROR Failed to decode public key.");
return;
}
// Execute ECDH with device private key.
uint8_t secret[32] = {0};
size_t secret_size = 0;
optiga_result ret = optiga_calc_ssec(OPTIGA_CURVE_P256, OID_KEY_DEV,
public_key, sizeof(public_key), secret,
sizeof(secret), &secret_size);
if (OPTIGA_SUCCESS != ret) {
memzero(secret, sizeof(secret));
vcp_println("ERROR optiga_calc_ssec error %d.", ret);
return;
}
// Hash the shared secret. Use the result as the decryption key.
sha256_Raw(secret, secret_size, secret);
aes_decrypt_ctx ctx = {0};
AES_RETURN aes_ret = aes_decrypt_key256(secret, &ctx);
if (EXIT_SUCCESS != aes_ret) {
vcp_println("ERROR aes_decrypt_key256 error.");
memzero(&ctx, sizeof(ctx));
memzero(secret, sizeof(secret));
return;
}
// Decrypt the FIDO attestation key.
uint8_t fido_key[PAYLOAD_SIZE];
// The IV is intentionally all-zero, which is not a problem, because the
// encryption key is unique for each ciphertext.
uint8_t iv[AES_BLOCK_SIZE] = {0};
aes_ret = aes_cbc_decrypt(&data_bytes[CIPHERTEXT_OFFSET], fido_key,
sizeof(fido_key), iv, &ctx);
memzero(&ctx, sizeof(ctx));
memzero(secret, sizeof(secret));
if (EXIT_SUCCESS != aes_ret) {
memzero(fido_key, sizeof(fido_key));
vcp_println("ERROR aes_cbc_decrypt error.");
return;
}
// Write trust anchor certificate to OID 0xE0E8
ret = optiga_set_trust_anchor();
if (OPTIGA_SUCCESS != ret) {
memzero(fido_key, sizeof(fido_key));
vcp_println("ERROR optiga_set_trust_anchor error %d.", ret);
return;
}
// Set change access condition for the FIDO key to Int(0xE0E8), so that we
// can write the FIDO key using the trust anchor in OID 0xE0E8.
memzero(&metadata, sizeof(metadata));
metadata.change.ptr = (const uint8_t *)"\x21\xe0\xe8";
metadata.change.len = 3;
if (!set_metadata(OID_KEY_FIDO, &metadata)) {
return;
}
// Store the FIDO attestation key.
ret = optiga_set_priv_key(OID_KEY_FIDO, fido_key);
memzero(fido_key, sizeof(fido_key));
if (OPTIGA_SUCCESS != ret) {
vcp_println("ERROR optiga_set_priv_key error %d.", ret);
return;
}
vcp_println("OK");
}