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trezor-firmware/legacy/firmware/crypto.c
2019-04-15 19:14:58 +02:00

499 lines
17 KiB
C

/*
* This file is part of the TREZOR project, https://trezor.io/
*
* Copyright (C) 2014 Pavol Rusnak <stick@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 "crypto.h"
#include <string.h>
#include "address.h"
#include "aes/aes.h"
#include "base58.h"
#include "bip32.h"
#include "cash_addr.h"
#include "coins.h"
#include "curves.h"
#include "hmac.h"
#include "layout.h"
#include "pbkdf2.h"
#include "secp256k1.h"
#include "segwit_addr.h"
#include "sha2.h"
uint32_t ser_length(uint32_t len, uint8_t *out) {
if (len < 253) {
out[0] = len & 0xFF;
return 1;
}
if (len < 0x10000) {
out[0] = 253;
out[1] = len & 0xFF;
out[2] = (len >> 8) & 0xFF;
return 3;
}
out[0] = 254;
out[1] = len & 0xFF;
out[2] = (len >> 8) & 0xFF;
out[3] = (len >> 16) & 0xFF;
out[4] = (len >> 24) & 0xFF;
return 5;
}
uint32_t ser_length_hash(Hasher *hasher, uint32_t len) {
if (len < 253) {
hasher_Update(hasher, (const uint8_t *)&len, 1);
return 1;
}
if (len < 0x10000) {
uint8_t d = 253;
hasher_Update(hasher, &d, 1);
hasher_Update(hasher, (const uint8_t *)&len, 2);
return 3;
}
uint8_t d = 254;
hasher_Update(hasher, &d, 1);
hasher_Update(hasher, (const uint8_t *)&len, 4);
return 5;
}
uint32_t deser_length(const uint8_t *in, uint32_t *out) {
if (in[0] < 253) {
*out = in[0];
return 1;
}
if (in[0] == 253) {
*out = in[1] + (in[2] << 8);
return 1 + 2;
}
if (in[0] == 254) {
*out = in[1] + (in[2] << 8) + (in[3] << 16) + ((uint32_t)in[4] << 24);
return 1 + 4;
}
*out = 0; // ignore 64 bit
return 1 + 8;
}
int sshMessageSign(HDNode *node, const uint8_t *message, size_t message_len,
uint8_t *signature) {
signature[0] = 0; // prefix: pad with zero, so all signatures are 65 bytes
return hdnode_sign(node, message, message_len, HASHER_SHA2, signature + 1,
NULL, NULL);
}
int gpgMessageSign(HDNode *node, const uint8_t *message, size_t message_len,
uint8_t *signature) {
signature[0] = 0; // prefix: pad with zero, so all signatures are 65 bytes
const curve_info *ed25519_curve_info = get_curve_by_name(ED25519_NAME);
if (ed25519_curve_info && node->curve == ed25519_curve_info) {
// GPG supports variable size digest for Ed25519 signatures
return hdnode_sign(node, message, message_len, 0, signature + 1, NULL,
NULL);
} else {
// Ensure 256-bit digest before proceeding
if (message_len != 32) {
return 1;
}
return hdnode_sign_digest(node, message, signature + 1, NULL, NULL);
}
}
static void cryptoMessageHash(const CoinInfo *coin, const uint8_t *message,
size_t message_len,
uint8_t hash[HASHER_DIGEST_LENGTH]) {
Hasher hasher;
hasher_Init(&hasher, coin->curve->hasher_sign);
hasher_Update(&hasher, (const uint8_t *)coin->signed_message_header,
strlen(coin->signed_message_header));
uint8_t varint[5];
uint32_t l = ser_length(message_len, varint);
hasher_Update(&hasher, varint, l);
hasher_Update(&hasher, message, message_len);
hasher_Final(&hasher, hash);
}
int cryptoMessageSign(const CoinInfo *coin, HDNode *node,
InputScriptType script_type, const uint8_t *message,
size_t message_len, uint8_t *signature) {
uint8_t hash[HASHER_DIGEST_LENGTH];
cryptoMessageHash(coin, message, message_len, hash);
uint8_t pby;
int result = hdnode_sign_digest(node, hash, signature + 1, &pby, NULL);
if (result == 0) {
switch (script_type) {
case InputScriptType_SPENDP2SHWITNESS:
// segwit-in-p2sh
signature[0] = 35 + pby;
break;
case InputScriptType_SPENDWITNESS:
// segwit
signature[0] = 39 + pby;
break;
default:
// p2pkh
signature[0] = 31 + pby;
break;
}
}
return result;
}
int cryptoMessageVerify(const CoinInfo *coin, const uint8_t *message,
size_t message_len, const char *address,
const uint8_t *signature) {
// check for invalid signature prefix
if (signature[0] < 27 || signature[0] > 43) {
return 1;
}
uint8_t hash[HASHER_DIGEST_LENGTH];
cryptoMessageHash(coin, message, message_len, hash);
uint8_t recid = (signature[0] - 27) % 4;
bool compressed = signature[0] >= 31;
// check if signature verifies the digest and recover the public key
uint8_t pubkey[65];
if (ecdsa_recover_pub_from_sig(coin->curve->params, pubkey, signature + 1,
hash, recid) != 0) {
return 3;
}
// convert public key to compressed pubkey if necessary
if (compressed) {
pubkey[0] = 0x02 | (pubkey[64] & 1);
}
// check if the address is correct
uint8_t addr_raw[MAX_ADDR_RAW_SIZE];
uint8_t recovered_raw[MAX_ADDR_RAW_SIZE];
// p2pkh
if (signature[0] >= 27 && signature[0] <= 34) {
size_t len;
if (coin->cashaddr_prefix) {
if (!cash_addr_decode(addr_raw, &len, coin->cashaddr_prefix, address)) {
return 2;
}
} else {
len = base58_decode_check(address, coin->curve->hasher_base58, addr_raw,
MAX_ADDR_RAW_SIZE);
}
ecdsa_get_address_raw(pubkey, coin->address_type,
coin->curve->hasher_pubkey, recovered_raw);
if (memcmp(recovered_raw, addr_raw, len) != 0 ||
len != address_prefix_bytes_len(coin->address_type) + 20) {
return 2;
}
} else
// segwit-in-p2sh
if (signature[0] >= 35 && signature[0] <= 38) {
size_t len = base58_decode_check(address, coin->curve->hasher_base58,
addr_raw, MAX_ADDR_RAW_SIZE);
ecdsa_get_address_segwit_p2sh_raw(pubkey, coin->address_type_p2sh,
coin->curve->hasher_pubkey,
recovered_raw);
if (memcmp(recovered_raw, addr_raw, len) != 0 ||
len != address_prefix_bytes_len(coin->address_type_p2sh) + 20) {
return 2;
}
} else
// segwit
if (signature[0] >= 39 && signature[0] <= 42) {
int witver;
size_t len;
if (!coin->bech32_prefix ||
!segwit_addr_decode(&witver, recovered_raw, &len, coin->bech32_prefix,
address)) {
return 4;
}
ecdsa_get_pubkeyhash(pubkey, coin->curve->hasher_pubkey, addr_raw);
if (memcmp(recovered_raw, addr_raw, len) != 0 || witver != 0 || len != 20) {
return 2;
}
} else {
return 4;
}
return 0;
}
/* ECIES disabled
int cryptoMessageEncrypt(curve_point *pubkey, const uint8_t *msg, size_t
msg_size, bool display_only, uint8_t *nonce, size_t *nonce_len, uint8_t
*payload, size_t *payload_len, uint8_t *hmac, size_t *hmac_len, const uint8_t
*privkey, const uint8_t *address_raw)
{
if (privkey && address_raw) { // signing == true
HDNode node;
payload[0] = display_only ? 0x81 : 0x01;
uint32_t l = ser_length(msg_size, payload + 1);
memcpy(payload + 1 + l, msg, msg_size);
memcpy(payload + 1 + l + msg_size, address_raw, 21);
hdnode_from_xprv(0, 0, 0, privkey, privkey, SECP256K1_NAME,
&node); if (cryptoMessageSign(&node, msg, msg_size, payload + 1 + l + msg_size +
21) != 0) { return 1;
}
*payload_len = 1 + l + msg_size + 21 + 65;
} else {
payload[0] = display_only ? 0x80 : 0x00;
uint32_t l = ser_length(msg_size, payload + 1);
memcpy(payload + 1 + l, msg, msg_size);
*payload_len = 1 + l + msg_size;
}
// generate random nonce
curve_point R;
bignum256 k;
if (generate_k_random(&secp256k1, &k) != 0) {
return 2;
}
// compute k*G
scalar_multiply(&secp256k1, &k, &R);
nonce[0] = 0x02 | (R.y.val[0] & 0x01);
bn_write_be(&R.x, nonce + 1);
*nonce_len = 33;
// compute shared secret
point_multiply(&secp256k1, &k, pubkey, &R);
uint8_t shared_secret[33];
shared_secret[0] = 0x02 | (R.y.val[0] & 0x01);
bn_write_be(&R.x, shared_secret + 1);
// generate keying bytes
uint8_t keying_bytes[80];
uint8_t salt[22 + 33];
memcpy(salt, "Bitcoin Secure Message", 22);
memcpy(salt + 22, nonce, 33);
pbkdf2_hmac_sha256(shared_secret, 33, salt, 22 + 33, 2048, keying_bytes,
80);
// encrypt payload
aes_encrypt_ctx ctx;
aes_encrypt_key256(keying_bytes, &ctx);
aes_cfb_encrypt(payload, payload, *payload_len, keying_bytes + 64,
&ctx);
// compute hmac
uint8_t out[32];
hmac_sha256(keying_bytes + 32, 32, payload, *payload_len, out);
memcpy(hmac, out, 8);
*hmac_len = 8;
return 0;
}
int cryptoMessageDecrypt(curve_point *nonce, uint8_t *payload, size_t
payload_len, const uint8_t *hmac, size_t hmac_len, const uint8_t *privkey,
uint8_t *msg, size_t *msg_len, bool *display_only, bool *signing, uint8_t
*address_raw)
{
if (hmac_len != 8) {
return 1;
}
// compute shared secret
curve_point R;
bignum256 k;
bn_read_be(privkey, &k);
point_multiply(&secp256k1, &k, nonce, &R);
uint8_t shared_secret[33];
shared_secret[0] = 0x02 | (R.y.val[0] & 0x01);
bn_write_be(&R.x, shared_secret + 1);
// generate keying bytes
uint8_t keying_bytes[80];
uint8_t salt[22 + 33];
memcpy(salt, "Bitcoin Secure Message", 22);
salt[22] = 0x02 | (nonce->y.val[0] & 0x01);
bn_write_be(&(nonce->x), salt + 23);
pbkdf2_hmac_sha256(shared_secret, 33, salt, 22 + 33, 2048, keying_bytes,
80);
// compute hmac
uint8_t out[32];
hmac_sha256(keying_bytes + 32, 32, payload, payload_len, out);
if (memcmp(hmac, out, 8) != 0) {
return 2;
}
// decrypt payload
aes_encrypt_ctx ctx;
aes_encrypt_key256(keying_bytes, &ctx);
aes_cfb_decrypt(payload, payload, payload_len, keying_bytes + 64, &ctx);
// check first byte
if (payload[0] != 0x00 && payload[0] != 0x01 && payload[0] != 0x80 &&
payload[0] != 0x81) { return 3;
}
*signing = payload[0] & 0x01;
*display_only = payload[0] & 0x80;
uint32_t l, o;
l = deser_length(payload + 1, &o);
if (*signing) {
// FIXME: assumes a raw address is 21 bytes (also below).
if (1 + l + o + 21 + 65 != payload_len) {
return 4;
}
// FIXME: cryptoMessageVerify changed to take the address_type
as a parameter. if (cryptoMessageVerify(payload + 1 + l, o, payload + 1 + l + o,
payload + 1 + l + o + 21) != 0) { return 5;
}
memcpy(address_raw, payload + 1 + l + o, 21);
} else {
if (1 + l + o != payload_len) {
return 4;
}
}
memcpy(msg, payload + 1 + l, o);
*msg_len = o;
return 0;
}
*/
const HDNode *cryptoMultisigPubkey(const CoinInfo *coin,
const MultisigRedeemScriptType *multisig,
uint32_t index) {
const HDNodeType *node_ptr;
const uint32_t *address_n;
uint32_t address_n_count;
if (multisig->nodes_count) { // use multisig->nodes
if (index >= multisig->nodes_count) {
return 0;
}
node_ptr = &(multisig->nodes[index]);
address_n = multisig->address_n;
address_n_count = multisig->address_n_count;
} else if (multisig->pubkeys_count) { // use multisig->pubkeys
if (index >= multisig->pubkeys_count) {
return 0;
}
node_ptr = &(multisig->pubkeys[index].node);
address_n = multisig->pubkeys[index].address_n;
address_n_count = multisig->pubkeys[index].address_n_count;
} else {
return 0;
}
if (node_ptr->chain_code.size != 32) return 0;
if (!node_ptr->has_public_key || node_ptr->public_key.size != 33) return 0;
static HDNode node;
if (!hdnode_from_xpub(node_ptr->depth, node_ptr->child_num,
node_ptr->chain_code.bytes, node_ptr->public_key.bytes,
coin->curve_name, &node)) {
return 0;
}
layoutProgressUpdate(true);
for (uint32_t i = 0; i < address_n_count; i++) {
if (!hdnode_public_ckd(&node, address_n[i])) {
return 0;
}
layoutProgressUpdate(true);
}
return &node;
}
uint32_t cryptoMultisigPubkeyCount(const MultisigRedeemScriptType *multisig) {
return multisig->nodes_count ? multisig->nodes_count
: multisig->pubkeys_count;
}
int cryptoMultisigPubkeyIndex(const CoinInfo *coin,
const MultisigRedeemScriptType *multisig,
const uint8_t *pubkey) {
for (size_t i = 0; i < cryptoMultisigPubkeyCount(multisig); i++) {
const HDNode *pubnode = cryptoMultisigPubkey(coin, multisig, i);
if (pubnode && memcmp(pubnode->public_key, pubkey, 33) == 0) {
return i;
}
}
return -1;
}
int cryptoMultisigFingerprint(const MultisigRedeemScriptType *multisig,
uint8_t *hash) {
static const HDNodeType *pubnodes[15], *swap;
const uint32_t n = cryptoMultisigPubkeyCount(multisig);
if (n < 1 || n > 15) {
return 0;
}
if (!multisig->has_m || multisig->m < 1 || multisig->m > 15) {
return 0;
}
for (uint32_t i = 0; i < n; i++) {
if (multisig->nodes_count) { // use multisig->nodes
pubnodes[i] = &(multisig->nodes[i]);
} else if (multisig->pubkeys_count) { // use multisig->pubkeys
pubnodes[i] = &(multisig->pubkeys[i].node);
} else {
return 0;
}
}
for (uint32_t i = 0; i < n; i++) {
if (!pubnodes[i]->has_public_key || pubnodes[i]->public_key.size != 33)
return 0;
if (pubnodes[i]->chain_code.size != 32) return 0;
}
// minsort according to pubkey
for (uint32_t i = 0; i < n - 1; i++) {
for (uint32_t j = n - 1; j > i; j--) {
if (memcmp(pubnodes[i]->public_key.bytes, pubnodes[j]->public_key.bytes,
33) > 0) {
swap = pubnodes[i];
pubnodes[i] = pubnodes[j];
pubnodes[j] = swap;
}
}
}
// hash sorted nodes
SHA256_CTX ctx;
sha256_Init(&ctx);
sha256_Update(&ctx, (const uint8_t *)&(multisig->m), sizeof(uint32_t));
for (uint32_t i = 0; i < n; i++) {
sha256_Update(&ctx, (const uint8_t *)&(pubnodes[i]->depth),
sizeof(uint32_t));
sha256_Update(&ctx, (const uint8_t *)&(pubnodes[i]->fingerprint),
sizeof(uint32_t));
sha256_Update(&ctx, (const uint8_t *)&(pubnodes[i]->child_num),
sizeof(uint32_t));
sha256_Update(&ctx, pubnodes[i]->chain_code.bytes, 32);
sha256_Update(&ctx, pubnodes[i]->public_key.bytes, 33);
}
sha256_Update(&ctx, (const uint8_t *)&n, sizeof(uint32_t));
sha256_Final(&ctx, hash);
layoutProgressUpdate(true);
return 1;
}
int cryptoIdentityFingerprint(const IdentityType *identity, uint8_t *hash) {
SHA256_CTX ctx;
sha256_Init(&ctx);
sha256_Update(&ctx, (const uint8_t *)&(identity->index), sizeof(uint32_t));
if (identity->has_proto && identity->proto[0]) {
sha256_Update(&ctx, (const uint8_t *)(identity->proto),
strlen(identity->proto));
sha256_Update(&ctx, (const uint8_t *)"://", 3);
}
if (identity->has_user && identity->user[0]) {
sha256_Update(&ctx, (const uint8_t *)(identity->user),
strlen(identity->user));
sha256_Update(&ctx, (const uint8_t *)"@", 1);
}
if (identity->has_host && identity->host[0]) {
sha256_Update(&ctx, (const uint8_t *)(identity->host),
strlen(identity->host));
}
if (identity->has_port && identity->port[0]) {
sha256_Update(&ctx, (const uint8_t *)":", 1);
sha256_Update(&ctx, (const uint8_t *)(identity->port),
strlen(identity->port));
}
if (identity->has_path && identity->path[0]) {
sha256_Update(&ctx, (const uint8_t *)(identity->path),
strlen(identity->path));
}
sha256_Final(&ctx, hash);
return 1;
}