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trezor-firmware/legacy/firmware/ethereum_definitions.c

341 lines
11 KiB
C

/*
* This file is part of the Trezor project, https://trezor.io/
*
* Copyright (C) 2022 Martin Novak <martin.novak@satoshilabs.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdbool.h>
#include <string.h>
#include "crypto.h"
#include "ethereum.h"
#include "ethereum_definitions.h"
#include "ethereum_definitions_constants.h"
#include "ethereum_networks.h"
#include "ethereum_tokens.h"
#include "fsm.h"
#include "gettext.h"
#include "memzero.h"
#include "messages.h"
#include "pb.h"
#include "pb_decode.h"
#include "trezor.h" // because of the "VERSTR" macro used in "fsm_sendFailureDebug" function
#include "util.h"
typedef pb_byte_t proof_entry[SHA256_DIGEST_LENGTH];
#define SIGNATURE_THRESHOLD 2
#define DEFS_PUBLIC_KEYS_COUNT 3
const ed25519_public_key DEFS_PUBLIC_KEYS[DEFS_PUBLIC_KEYS_COUNT] = {
"\x43\x34\x99\x63\x43\x62\x3e\x46\x2f\x0f\xc9\x33\x11\xfe\xf1\x48\x4c\xa2"
"\x3d\x2f\xf1\xee\xc6\xdf\x1f\xa8\xeb\x7e\x35\x73\xb3\xdb",
"\xa9\xa2\x2c\xc2\x65\xa0\xcb\x1d\x6c\xb3\x29\xbc\x0e\x60\xbc\x45\xdf\x76"
"\xb9\xab\x28\xfb\x87\xb6\x11\x36\xfe\xaf\x8d\x8f\xdc\x96",
"\xb8\xd2\xb2\x1d\xe2\x71\x24\xf0\x51\x1f\x90\x3a\xe7\xe6\x0e\x07\x96\x18"
"\x10\xa0\xb8\xf2\x8e\xa7\x55\xfa\x50\x36\x7a\x8a\x2b\x8b",
};
#if DEBUG_LINK
const ed25519_public_key DEFS_PUBLIC_KEYS_DEV[DEFS_PUBLIC_KEYS_COUNT] = {
"\x68\x46\x0e\xbe\xf3\xb1\x38\x16\x4e\xc7\xfd\x86\x10\xe9\x58\x00\xdf"
"\x75\x98\xf7\x0f\x2f\x2e\xa7\xdb\x51\x72\xac\x74\xeb\xc1\x44",
"\x8d\x4a\xbe\x07\x4f\xef\x92\x29\xd3\xb4\x41\xdf\xea\x4f\x98\xf8\x05"
"\xb1\xa2\xb3\xa0\x6a\xe6\x45\x81\x0e\xfe\xce\x77\xfd\x50\x44",
"\x97\xf7\x13\x5a\x9a\x26\x90\xe7\x3b\xeb\x26\x55\x6f\x1c\xb1\x63\xbe"
"\xa2\x53\x2a\xff\xa1\xe7\x78\x24\x30\xbe\x98\xc0\xe5\x68\x12",
};
#endif
struct EncodedDefinition {
// prefix
pb_byte_t format_version[FORMAT_VERSION_LENGTH];
uint8_t definition_type;
uint32_t data_version;
uint16_t payload_length;
// payload
const pb_byte_t *payload;
// suffix
uint8_t proof_length;
const proof_entry *proof;
uint8_t sigmask;
const uint8_t *signature;
};
static bool parse_encoded_definition(struct EncodedDefinition *const result,
const pb_size_t size,
const pb_byte_t *bytes) {
// format version + definition type + data version + payload length + payload
// (at least 1B) + proof length + sigmask + signature
if (size < (FORMAT_VERSION_LENGTH + 1 + 4 + 2 + 1 + 1 + 1 +
sizeof(ed25519_signature))) {
return false;
}
const pb_byte_t *cursor = bytes;
memcpy(result->format_version, cursor, FORMAT_VERSION_LENGTH);
cursor += FORMAT_VERSION_LENGTH;
result->definition_type = *cursor;
cursor += 1;
result->data_version = *(uint32_t *)cursor;
cursor += 4;
result->payload_length = *(uint16_t *)cursor;
cursor += 2;
result->payload = cursor;
cursor += result->payload_length;
if (size <= cursor - bytes) {
return false;
}
result->proof_length = *cursor;
cursor += 1;
// check the whole size of incoming bytes array
if (size != (cursor - bytes) + result->proof_length * sizeof(proof_entry) +
1 + sizeof(ed25519_signature)) {
return false;
}
result->proof = (proof_entry *)cursor;
cursor += result->proof_length * sizeof(proof_entry);
result->sigmask = *cursor;
cursor += 1;
result->signature = cursor;
return true;
}
static bool decode_definition(const pb_size_t size, const pb_byte_t *bytes,
const EthereumDefinitionType expected_type,
void *definition) {
// parse received definition
static struct EncodedDefinition parsed_def;
const char *error_str = _("Invalid Ethereum definition");
memzero(&parsed_def, sizeof(parsed_def));
if (!parse_encoded_definition(&parsed_def, size, bytes)) {
goto err;
}
// check definition fields
if (memcmp(FORMAT_VERSION, parsed_def.format_version,
FORMAT_VERSION_LENGTH)) {
goto err;
}
if (expected_type != parsed_def.definition_type) {
error_str = _("Definition type mismatch");
goto err;
}
if (MIN_DATA_VERSION > parsed_def.data_version) {
error_str = _("Definition is outdated");
goto err;
}
// compute Merkle tree root hash from proof
uint8_t hash[SHA256_DIGEST_LENGTH] = {0};
SHA256_CTX context = {0};
sha256_Init(&context);
// leaf hash = sha256('\x00' + leaf data)
sha256_Update(&context, (uint8_t[]){0}, 1);
// signed data is everything from start of `bytes` to the end of `payload`
const pb_byte_t *payload_end = parsed_def.payload + parsed_def.payload_length;
size_t signed_data_size = payload_end - bytes;
sha256_Update(&context, bytes, signed_data_size);
sha256_Final(&context, hash);
const uint8_t *min, *max;
for (uint8_t i = 0; i < parsed_def.proof_length; i++) {
sha256_Init(&context);
// node hash = sha256('\x01' + min(hash, next_proof) + max(hash,
// next_proof))
sha256_Update(&context, (uint8_t[]){1}, 1);
if (memcmp(hash, parsed_def.proof[i], SHA256_DIGEST_LENGTH) <= 0) {
min = hash;
max = parsed_def.proof[i];
} else {
min = parsed_def.proof[i];
max = hash;
}
sha256_Update(&context, min, SHA256_DIGEST_LENGTH);
sha256_Update(&context, max, SHA256_DIGEST_LENGTH);
sha256_Final(&context, hash);
}
// and verify its signature
if (!cryptoCosiVerify(parsed_def.signature, hash, sizeof(hash),
SIGNATURE_THRESHOLD, DEFS_PUBLIC_KEYS,
DEFS_PUBLIC_KEYS_COUNT, parsed_def.sigmask)
#if DEBUG_LINK
&& !cryptoCosiVerify(parsed_def.signature, hash, sizeof(hash),
SIGNATURE_THRESHOLD, DEFS_PUBLIC_KEYS_DEV,
DEFS_PUBLIC_KEYS_COUNT, parsed_def.sigmask)
#endif
) {
// invalid signature
error_str = _("Invalid definition signature");
goto err;
}
// decode message
const pb_msgdesc_t *fields = (expected_type == EthereumDefinitionType_NETWORK
? EthereumNetworkInfo_fields
: EthereumTokenInfo_fields);
pb_istream_t stream =
pb_istream_from_buffer(parsed_def.payload, parsed_def.payload_length);
bool status = pb_decode(&stream, fields, definition);
if (status) {
return true;
}
// fallthrough to error handling in case of decoding failure
err:
memzero(&parsed_def, sizeof(parsed_def));
fsm_sendFailure(FailureType_Failure_DataError, error_str);
return false;
}
static const EthereumNetworkInfo *get_network(
const EncodedNetwork *encoded_network, const uint64_t chain_id,
const uint32_t slip44) {
static EthereumNetworkInfo decoded_network;
const EthereumNetworkInfo *network = &UNKNOWN_NETWORK;
// try to get built-in definition
if (chain_id != CHAIN_ID_UNKNOWN) {
network = ethereum_get_network_by_chain_id(chain_id);
} else if (slip44 != SLIP44_UNKNOWN) {
network = ethereum_get_network_by_slip44(slip44);
} else {
// if both chain_id and slip44 is unspecified, we do not have anything to
// match to the encoded definition, so just short-circuit here
return &UNKNOWN_NETWORK;
}
// if we found built-in definition, or if there's no data to decode, we are
// done
if (!is_unknown_network(network) || encoded_network == NULL) {
return network;
}
// if we still do not have any network definition try to decode received data
memzero(&decoded_network, sizeof(decoded_network));
if (!decode_definition(encoded_network->size, encoded_network->bytes,
EthereumDefinitionType_NETWORK, &decoded_network)) {
// error already sent by decode_definition
return NULL;
}
if (chain_id != CHAIN_ID_UNKNOWN && decoded_network.chain_id != chain_id) {
fsm_sendFailure(FailureType_Failure_DataError,
_("Network definition mismatch"));
return NULL;
}
if (slip44 != SLIP44_UNKNOWN && decoded_network.slip44 != slip44) {
fsm_sendFailure(FailureType_Failure_DataError,
_("Network definition mismatch"));
return NULL;
}
return &decoded_network;
}
static const EthereumTokenInfo *get_token(const EncodedToken *encoded_token,
const uint64_t chain_id,
const char *address) {
static EthereumTokenInfo decoded_token;
// if we do not know the chain_id, we cannot get the token
if (chain_id == CHAIN_ID_UNKNOWN) {
return &UNKNOWN_TOKEN;
}
// convert address string to bytes
EthereumTokenInfo_address_t address_bytes;
bool address_parsed = address && ethereum_parse(address, address_bytes.bytes);
if (!address_parsed) {
// without a valid address, we cannot get the token
return &UNKNOWN_TOKEN;
}
// try to get built-in definition
const EthereumTokenInfo *token =
ethereum_token_by_address(chain_id, address_bytes.bytes);
if (!is_unknown_token(token) || encoded_token == NULL) {
// if we found one, or if there's no data to decode, we are done
return token;
}
// try to decode received definition
memzero(&decoded_token, sizeof(decoded_token));
if (!decode_definition(encoded_token->size, encoded_token->bytes,
EthereumDefinitionType_TOKEN, &decoded_token)) {
// error already sent by decode_definition
return NULL;
}
if (decoded_token.chain_id != chain_id ||
memcmp(decoded_token.address.bytes, address_bytes.bytes,
sizeof(decoded_token.address.bytes))) {
// receiving a mismatched token is not an error (we expect being able to get
// multiple token definitions in the future, for multiple networks)
// but we must not accept the mismatched definition
memzero(&decoded_token, sizeof(decoded_token));
return &UNKNOWN_TOKEN;
}
return &decoded_token;
}
const EthereumDefinitionsDecoded *ethereum_get_definitions(
const EncodedNetwork *encoded_network, const EncodedToken *encoded_token,
const uint64_t chain_id, const uint32_t slip44, const char *token_address) {
static EthereumDefinitionsDecoded defs;
memzero(&defs, sizeof(defs));
const EthereumNetworkInfo *network =
get_network(encoded_network, chain_id, slip44);
if (network == NULL) {
// error while decoding, failure was sent by get_network
return NULL;
}
defs.network = network;
if (!is_unknown_network(network) && token_address != NULL) {
const EthereumTokenInfo *token =
get_token(encoded_token, network->chain_id, token_address);
if (token == NULL) {
// error while decoding, failure was sent by get_token
return NULL;
}
defs.token = token;
} else {
defs.token = &UNKNOWN_TOKEN;
}
return &defs;
}