core-lightning/hsmd/hsm.c
Rusty Russell bbed5e3411 Rename subdaemons, move them into top level.
We leave the *build* results in lightningd/ for ease of in-place testing though.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2017-08-29 17:54:14 +02:00

678 lines
19 KiB
C

#include <bitcoin/address.h>
#include <bitcoin/privkey.h>
#include <bitcoin/pubkey.h>
#include <bitcoin/script.h>
#include <bitcoin/tx.h>
#include <ccan/breakpoint/breakpoint.h>
#include <ccan/container_of/container_of.h>
#include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
#include <ccan/endian/endian.h>
#include <ccan/fdpass/fdpass.h>
#include <ccan/io/fdpass/fdpass.h>
#include <ccan/io/io.h>
#include <ccan/noerr/noerr.h>
#include <ccan/ptrint/ptrint.h>
#include <ccan/read_write_all/read_write_all.h>
#include <ccan/take/take.h>
#include <common/daemon_conn.h>
#include <common/funding_tx.h>
#include <common/status.h>
#include <common/utils.h>
#include <common/version.h>
#include <common/withdraw_tx.h>
#include <errno.h>
#include <fcntl.h>
#include <hsmd/client.h>
#include <hsmd/gen_hsm_client_wire.h>
#include <hsmd/gen_hsm_wire.h>
#include <inttypes.h>
#include <secp256k1_ecdh.h>
#include <sodium/randombytes.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <wally_bip32.h>
#include <wire/gen_peer_wire.h>
#include <wire/wire_io.h>
/* Nobody will ever find it here! */
static struct {
struct secret hsm_secret;
struct ext_key bip32;
} secretstuff;
struct client {
struct daemon_conn dc;
struct daemon_conn *master;
u64 id;
struct io_plan *(*handle)(struct io_conn *, struct daemon_conn *);
};
static void node_key(struct privkey *node_privkey, struct pubkey *node_id)
{
u32 salt = 0;
struct privkey unused_s;
struct pubkey unused_k;
if (node_privkey == NULL)
node_privkey = &unused_s;
else if (node_id == NULL)
node_id = &unused_k;
do {
hkdf_sha256(node_privkey, sizeof(*node_privkey),
&salt, sizeof(salt),
&secretstuff.hsm_secret,
sizeof(secretstuff.hsm_secret),
"nodeid", 6);
salt++;
} while (!secp256k1_ec_pubkey_create(secp256k1_ctx, &node_id->pubkey,
node_privkey->secret.data));
}
static struct client *new_client(struct daemon_conn *master,
u64 id,
struct io_plan *(*handle)(struct io_conn *,
struct daemon_conn *),
int fd)
{
struct client *c = tal(master, struct client);
c->id = id;
c->handle = handle;
c->master = master;
daemon_conn_init(c, &c->dc, fd, handle, NULL);
/* Free the connection if we exit everything. */
tal_steal(master, c->dc.conn);
/* Free client when connection freed. */
tal_steal(c->dc.conn, c);
return c;
}
static struct io_plan *handle_ecdh(struct io_conn *conn, struct daemon_conn *dc)
{
struct client *c = container_of(dc, struct client, dc);
struct privkey privkey;
struct pubkey point;
struct secret ss;
if (!fromwire_hsm_ecdh_req(dc->msg_in, NULL, &point)) {
daemon_conn_send(c->master,
take(towire_hsmstatus_client_bad_request(c,
c->id,
dc->msg_in)));
return io_close(conn);
}
node_key(&privkey, NULL);
if (secp256k1_ecdh(secp256k1_ctx, ss.data, &point.pubkey,
privkey.secret.data) != 1) {
status_trace("secp256k1_ecdh fail for client %"PRIu64, c->id);
daemon_conn_send(c->master,
take(towire_hsmstatus_client_bad_request(c,
c->id,
dc->msg_in)));
return io_close(conn);
}
daemon_conn_send(dc, take(towire_hsm_ecdh_resp(c, &ss)));
return daemon_conn_read_next(conn, dc);
}
static struct io_plan *handle_cannouncement_sig(struct io_conn *conn,
struct daemon_conn *dc)
{
tal_t *ctx = tal_tmpctx(conn);
/* First 2 + 256 byte are the signatures and msg type, skip them */
size_t offset = 258;
struct privkey node_pkey;
secp256k1_ecdsa_signature node_sig;
struct sha256_double hash;
u8 *reply;
u8 *ca;
struct pubkey bitcoin_id;
if (!fromwire_hsm_cannouncement_sig_req(ctx, dc->msg_in, NULL,
&bitcoin_id, &ca)) {
status_trace("Failed to parse cannouncement_sig_req: %s",
tal_hex(trc, dc->msg_in));
return io_close(conn);
}
if (tal_len(ca) < offset) {
status_trace("bad cannounce length %zu", tal_len(ca));
return io_close(conn);
}
/* TODO(cdecker) Check that this is actually a valid
* channel_announcement */
node_key(&node_pkey, NULL);
sha256_double(&hash, ca + offset, tal_len(ca) - offset);
sign_hash(&node_pkey, &hash, &node_sig);
reply = towire_hsm_cannouncement_sig_reply(ca, &node_sig);
daemon_conn_send(dc, take(reply));
tal_free(ctx);
return daemon_conn_read_next(conn, dc);
}
static struct io_plan *handle_channel_update_sig(struct io_conn *conn,
struct daemon_conn *dc)
{
tal_t *tmpctx = tal_tmpctx(conn);
/* 2 bytes msg type + 64 bytes signature */
size_t offset = 66;
struct privkey node_pkey;
struct sha256_double hash;
secp256k1_ecdsa_signature sig;
struct short_channel_id scid;
u32 timestamp, fee_base_msat, fee_proportional_mill;
u64 htlc_minimum_msat;
u16 flags, cltv_expiry_delta;
struct sha256_double chain_hash;
u8 *cu;
if (!fromwire_hsm_cupdate_sig_req(tmpctx, dc->msg_in, NULL, &cu)) {
status_trace("Failed to parse %s: %s",
hsm_client_wire_type_name(fromwire_peektype(dc->msg_in)),
tal_hex(trc, dc->msg_in));
return io_close(conn);
}
if (!fromwire_channel_update(cu, NULL, &sig, &chain_hash,
&scid, &timestamp, &flags,
&cltv_expiry_delta, &htlc_minimum_msat,
&fee_base_msat, &fee_proportional_mill)) {
status_trace("Failed to parse inner channel_update: %s",
tal_hex(trc, dc->msg_in));
return io_close(conn);
}
if (tal_len(cu) < offset) {
status_trace("inner channel_update too short: %s",
tal_hex(trc, dc->msg_in));
return io_close(conn);
}
node_key(&node_pkey, NULL);
sha256_double(&hash, cu + offset, tal_len(cu) - offset);
sign_hash(&node_pkey, &hash, &sig);
cu = towire_channel_update(tmpctx, &sig, &chain_hash,
&scid, timestamp, flags,
cltv_expiry_delta, htlc_minimum_msat,
fee_base_msat, fee_proportional_mill);
daemon_conn_send(dc, take(towire_hsm_cupdate_sig_reply(tmpctx, cu)));
tal_free(tmpctx);
return daemon_conn_read_next(conn, dc);
}
static struct io_plan *handle_channeld(struct io_conn *conn,
struct daemon_conn *dc)
{
struct client *c = container_of(dc, struct client, dc);
enum hsm_client_wire_type t = fromwire_peektype(dc->msg_in);
switch (t) {
case WIRE_HSM_ECDH_REQ:
return handle_ecdh(conn, dc);
case WIRE_HSM_CANNOUNCEMENT_SIG_REQ:
return handle_cannouncement_sig(conn, dc);
case WIRE_HSM_CUPDATE_SIG_REQ:
return handle_channel_update_sig(conn, dc);
case WIRE_HSM_ECDH_RESP:
case WIRE_HSM_CANNOUNCEMENT_SIG_REPLY:
case WIRE_HSM_CUPDATE_SIG_REPLY:
break;
}
daemon_conn_send(c->master,
take(towire_hsmstatus_client_bad_request(c,
c->id,
dc->msg_in)));
return io_close(conn);
}
/* Control messages */
static void send_init_response(struct daemon_conn *master)
{
struct pubkey node_id;
struct secret peer_seed;
u8 *msg;
hkdf_sha256(&peer_seed, sizeof(peer_seed), NULL, 0,
&secretstuff.hsm_secret,
sizeof(secretstuff.hsm_secret),
"peer seed", strlen("peer seed"));
node_key(NULL, &node_id);
msg = towire_hsmctl_init_reply(master, &node_id, &peer_seed,
&secretstuff.bip32);
daemon_conn_send(master, take(msg));
}
static void populate_secretstuff(void)
{
u8 bip32_seed[BIP32_ENTROPY_LEN_256];
u32 salt = 0;
struct ext_key master_extkey, child_extkey;
/* Fill in the BIP32 tree for bitcoin addresses. */
do {
hkdf_sha256(bip32_seed, sizeof(bip32_seed),
&salt, sizeof(salt),
&secretstuff.hsm_secret,
sizeof(secretstuff.hsm_secret),
"bip32 seed", strlen("bip32 seed"));
salt++;
} while (bip32_key_from_seed(bip32_seed, sizeof(bip32_seed),
BIP32_VER_TEST_PRIVATE,
0, &master_extkey) != WALLY_OK);
/* BIP 32:
*
* The default wallet layout
*
* An HDW is organized as several 'accounts'. Accounts are numbered,
* the default account ("") being number 0. Clients are not required
* to support more than one account - if not, they only use the
* default account.
*
* Each account is composed of two keypair chains: an internal and an
* external one. The external keychain is used to generate new public
* addresses, while the internal keychain is used for all other
* operations (change addresses, generation addresses, ..., anything
* that doesn't need to be communicated). Clients that do not support
* separate keychains for these should use the external one for
* everything.
*
* - m/iH/0/k corresponds to the k'th keypair of the external chain of account number i of the HDW derived from master m.
*/
/* Hence child 0, then child 0 again to get extkey to derive from. */
if (bip32_key_from_parent(&master_extkey, 0, BIP32_FLAG_KEY_PRIVATE,
&child_extkey) != WALLY_OK)
status_failed(WIRE_HSMSTATUS_KEY_FAILED,
"Can't derive child bip32 key");
if (bip32_key_from_parent(&child_extkey, 0, BIP32_FLAG_KEY_PRIVATE,
&secretstuff.bip32) != WALLY_OK)
status_failed(WIRE_HSMSTATUS_KEY_FAILED,
"Can't derive private bip32 key");
}
static void bitcoin_pubkey(struct pubkey *pubkey, u32 index)
{
struct ext_key ext;
if (index >= BIP32_INITIAL_HARDENED_CHILD)
status_failed(WIRE_HSMSTATUS_KEY_FAILED,
"Index %u too great", index);
if (bip32_key_from_parent(&secretstuff.bip32, index,
BIP32_FLAG_KEY_PUBLIC, &ext) != WALLY_OK)
status_failed(WIRE_HSMSTATUS_KEY_FAILED,
"BIP32 of %u failed", index);
if (!secp256k1_ec_pubkey_parse(secp256k1_ctx, &pubkey->pubkey,
ext.pub_key, sizeof(ext.pub_key)))
status_failed(WIRE_HSMSTATUS_KEY_FAILED,
"Parse of BIP32 child %u pubkey failed", index);
}
static void bitcoin_keypair(struct privkey *privkey,
struct pubkey *pubkey,
u32 index)
{
struct ext_key ext;
if (index >= BIP32_INITIAL_HARDENED_CHILD)
status_failed(WIRE_HSMSTATUS_KEY_FAILED,
"Index %u too great", index);
if (bip32_key_from_parent(&secretstuff.bip32, index,
BIP32_FLAG_KEY_PRIVATE, &ext) != WALLY_OK)
status_failed(WIRE_HSMSTATUS_KEY_FAILED,
"BIP32 of %u failed", index);
/* libwally says: The private key with prefix byte 0 */
memcpy(privkey->secret.data, ext.priv_key+1, 32);
if (!secp256k1_ec_pubkey_create(secp256k1_ctx, &pubkey->pubkey,
privkey->secret.data))
status_failed(WIRE_HSMSTATUS_KEY_FAILED,
"BIP32 pubkey %u create failed", index);
}
static void create_new_hsm(struct daemon_conn *master)
{
int fd = open("hsm_secret", O_CREAT|O_EXCL|O_WRONLY, 0400);
if (fd < 0)
status_failed(WIRE_HSMSTATUS_INIT_FAILED,
"creating: %s", strerror(errno));
randombytes_buf(&secretstuff.hsm_secret, sizeof(secretstuff.hsm_secret));
if (!write_all(fd, &secretstuff.hsm_secret, sizeof(secretstuff.hsm_secret))) {
unlink_noerr("hsm_secret");
status_failed(WIRE_HSMSTATUS_INIT_FAILED,
"writing: %s", strerror(errno));
}
if (fsync(fd) != 0) {
unlink_noerr("hsm_secret");
status_failed(WIRE_HSMSTATUS_INIT_FAILED,
"fsync: %s", strerror(errno));
}
if (close(fd) != 0) {
unlink_noerr("hsm_secret");
status_failed(WIRE_HSMSTATUS_INIT_FAILED,
"closing: %s", strerror(errno));
}
fd = open(".", O_RDONLY);
if (fsync(fd) != 0) {
unlink_noerr("hsm_secret");
status_failed(WIRE_HSMSTATUS_INIT_FAILED,
"fsyncdir: %s", strerror(errno));
}
close(fd);
populate_secretstuff();
}
static void load_hsm(struct daemon_conn *master)
{
int fd = open("hsm_secret", O_RDONLY);
if (fd < 0)
status_failed(WIRE_HSMSTATUS_INIT_FAILED,
"opening: %s", strerror(errno));
if (!read_all(fd, &secretstuff.hsm_secret, sizeof(secretstuff.hsm_secret)))
status_failed(WIRE_HSMSTATUS_INIT_FAILED,
"reading: %s", strerror(errno));
close(fd);
populate_secretstuff();
}
static void init_hsm(struct daemon_conn *master, const u8 *msg)
{
bool new;
if (!fromwire_hsmctl_init(msg, NULL, &new))
status_failed(WIRE_HSMSTATUS_BAD_REQUEST, "hsmctl_init: %s",
tal_hex(msg, msg));
if (new)
create_new_hsm(master);
else
load_hsm(master);
send_init_response(master);
}
static void pass_hsmfd_ecdh(struct daemon_conn *master, const u8 *msg)
{
int fds[2];
u64 id;
if (!fromwire_hsmctl_hsmfd_ecdh(msg, NULL, &id))
status_failed(WIRE_HSMSTATUS_BAD_REQUEST, "bad HSMFD_ECDH");
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) != 0)
status_failed(WIRE_HSMSTATUS_FD_FAILED,
"creating fds: %s", strerror(errno));
new_client(master, id, handle_ecdh, fds[0]);
daemon_conn_send(master,
take(towire_hsmctl_hsmfd_ecdh_fd_reply(master)));
daemon_conn_send_fd(master, fds[1]);
}
/* Reply to an incoming request for an HSMFD for a channeld. */
static void pass_hsmfd_channeld(struct daemon_conn *master, const u8 *msg)
{
int fds[2];
u64 id;
if (!fromwire_hsmctl_hsmfd_channeld(msg, NULL, &id))
status_failed(WIRE_HSMSTATUS_BAD_REQUEST, "bad HSMFD_CHANNELD");
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) != 0)
status_failed(WIRE_HSMSTATUS_FD_FAILED,
"creating fds: %s", strerror(errno));
new_client(master, id, handle_channeld, fds[0]);
daemon_conn_send(master,
take(towire_hsmctl_hsmfd_channeld_reply(master)));
daemon_conn_send_fd(master, fds[1]);
}
/* Note that it's the main daemon that asks for the funding signature so it
* can broadcast it. */
static void sign_funding_tx(struct daemon_conn *master, const u8 *msg)
{
const tal_t *tmpctx = tal_tmpctx(master);
u64 satoshi_out, change_out;
u32 change_keyindex;
struct pubkey local_pubkey, remote_pubkey;
struct utxo *inputs;
const struct utxo **utxomap;
struct bitcoin_tx *tx;
u8 *wscript;
secp256k1_ecdsa_signature *sig;
u16 outnum;
size_t i;
struct pubkey changekey;
/* FIXME: Check fee is "reasonable" */
if (!fromwire_hsmctl_sign_funding(tmpctx, msg, NULL,
&satoshi_out, &change_out,
&change_keyindex, &local_pubkey,
&remote_pubkey, &inputs))
status_failed(WIRE_HSMSTATUS_BAD_REQUEST, "Bad SIGN_FUNDING");
utxomap = to_utxoptr_arr(tmpctx, inputs);
if (change_out)
bitcoin_pubkey(&changekey, change_keyindex);
tx = funding_tx(tmpctx, &outnum, utxomap,
satoshi_out, &local_pubkey, &remote_pubkey,
change_out, &changekey,
NULL);
/* Now generate signatures. */
sig = tal_arr(tmpctx, secp256k1_ecdsa_signature, tal_count(inputs));
for (i = 0; i < tal_count(inputs); i++) {
struct pubkey inkey;
struct privkey inprivkey;
const struct utxo *in = utxomap[i];
u8 *subscript;
bitcoin_keypair(&inprivkey, &inkey, in->keyindex);
if (in->is_p2sh)
subscript = bitcoin_redeem_p2sh_p2wpkh(tmpctx, &inkey);
else
subscript = NULL;
wscript = p2wpkh_scriptcode(tmpctx, &inkey);
sign_tx_input(tx, i, subscript, wscript,
&inprivkey, &inkey, &sig[i]);
}
daemon_conn_send(master,
take(towire_hsmctl_sign_funding_reply(tmpctx, sig)));
tal_free(tmpctx);
}
/**
* sign_withdrawal_tx - Generate and sign a withdrawal transaction from the master
*/
static void sign_withdrawal_tx(struct daemon_conn *master, const u8 *msg)
{
const tal_t *tmpctx = tal_tmpctx(master);
u64 satoshi_out, change_out;
u32 change_keyindex;
struct bitcoin_address destination;
struct utxo *utxos;
secp256k1_ecdsa_signature *sigs;
u8 *wscript;
struct bitcoin_tx *tx;
struct ext_key ext;
struct pubkey changekey;
if (!fromwire_hsmctl_sign_withdrawal(tmpctx, msg, NULL, &satoshi_out,
&change_out, &change_keyindex,
destination.addr.u.u8, &utxos)) {
status_trace("Failed to parse sign_withdrawal: %s",
tal_hex(trc, msg));
return;
}
if (bip32_key_from_parent(&secretstuff.bip32, change_keyindex,
BIP32_FLAG_KEY_PUBLIC, &ext) != WALLY_OK) {
status_trace("Failed to parse sign_withdrawal: %s",
tal_hex(trc, msg));
return;
}
pubkey_from_der(ext.pub_key, sizeof(ext.pub_key), &changekey);
tx = withdraw_tx(
tmpctx, to_utxoptr_arr(tmpctx, utxos), &destination, satoshi_out,
&changekey, change_out, NULL);
/* Now generate signatures. */
sigs = tal_arr(tmpctx, secp256k1_ecdsa_signature, tal_count(utxos));
for (size_t i = 0; i < tal_count(utxos); i++) {
struct pubkey inkey;
struct privkey inprivkey;
const struct utxo *in = &utxos[i];
u8 *subscript;
bitcoin_keypair(&inprivkey, &inkey, in->keyindex);
/* We know these are p2sh since that's the only kind we handle */
subscript = bitcoin_redeem_p2sh_p2wpkh(tmpctx, &inkey);
wscript = p2wpkh_scriptcode(tmpctx, &inkey);
sign_tx_input(tx, i, subscript, wscript,
&inprivkey, &inkey, &sigs[i]);
}
daemon_conn_send(master,
take(towire_hsmctl_sign_withdrawal_reply(tmpctx, sigs)));
tal_free(tmpctx);
}
static void sign_node_announcement(struct daemon_conn *master, const u8 *msg)
{
/* 2 bytes msg type + 64 bytes signature */
size_t offset = 66;
struct sha256_double hash;
struct privkey node_pkey;
secp256k1_ecdsa_signature sig;
u8 *reply;
u8 *ann;
if (!fromwire_hsmctl_node_announcement_sig_req(msg, msg, NULL, &ann)) {
status_trace("Failed to parse node_announcement_sig_req: %s",
tal_hex(trc, msg));
return;
}
if (tal_len(ann) < offset) {
status_trace("Node announcement too short: %s", tal_hex(trc, msg));
return;
}
/* FIXME(cdecker) Check the node announcement's content */
node_key(&node_pkey, NULL);
sha256_double(&hash, ann + offset, tal_len(ann) - offset);
sign_hash(&node_pkey, &hash, &sig);
reply = towire_hsmctl_node_announcement_sig_reply(msg, &sig);
daemon_conn_send(master, take(reply));
}
static struct io_plan *control_received_req(struct io_conn *conn,
struct daemon_conn *master)
{
enum hsm_wire_type t = fromwire_peektype(master->msg_in);
status_trace("Control: type %s len %zu",
hsm_wire_type_name(t), tal_count(master->msg_in));
switch (t) {
case WIRE_HSMCTL_INIT:
init_hsm(master, master->msg_in);
return daemon_conn_read_next(conn, master);
case WIRE_HSMCTL_HSMFD_ECDH:
pass_hsmfd_ecdh(master, master->msg_in);
return daemon_conn_read_next(conn, master);
case WIRE_HSMCTL_HSMFD_CHANNELD:
pass_hsmfd_channeld(master, master->msg_in);
return daemon_conn_read_next(conn, master);
case WIRE_HSMCTL_SIGN_FUNDING:
sign_funding_tx(master, master->msg_in);
return daemon_conn_read_next(conn, master);
case WIRE_HSMCTL_SIGN_WITHDRAWAL:
sign_withdrawal_tx(master, master->msg_in);
return daemon_conn_read_next(conn, master);
case WIRE_HSMCTL_NODE_ANNOUNCEMENT_SIG_REQ:
sign_node_announcement(master, master->msg_in);
return daemon_conn_read_next(conn, master);
case WIRE_HSMCTL_INIT_REPLY:
case WIRE_HSMCTL_HSMFD_ECDH_FD_REPLY:
case WIRE_HSMCTL_HSMFD_CHANNELD_REPLY:
case WIRE_HSMCTL_SIGN_FUNDING_REPLY:
case WIRE_HSMCTL_SIGN_WITHDRAWAL_REPLY:
case WIRE_HSMSTATUS_INIT_FAILED:
case WIRE_HSMSTATUS_WRITEMSG_FAILED:
case WIRE_HSMSTATUS_BAD_REQUEST:
case WIRE_HSMSTATUS_FD_FAILED:
case WIRE_HSMSTATUS_KEY_FAILED:
case WIRE_HSMSTATUS_CLIENT_BAD_REQUEST:
case WIRE_HSMCTL_NODE_ANNOUNCEMENT_SIG_REPLY:
break;
}
/* Control shouldn't give bad requests. */
status_failed(WIRE_HSMSTATUS_BAD_REQUEST, "%i", t);
}
#ifndef TESTING
static void master_gone(struct io_conn *unused, struct daemon_conn *dc)
{
/* Can't tell master, it's gone. */
exit(2);
}
int main(int argc, char *argv[])
{
struct daemon_conn *master;
if (argc == 2 && streq(argv[1], "--version")) {
printf("%s\n", version());
exit(0);
}
breakpoint();
secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
| SECP256K1_CONTEXT_SIGN);
master = tal(NULL, struct daemon_conn);
daemon_conn_init(master, master, STDIN_FILENO, control_received_req,
master_gone);
status_setup_async(master);
/* When conn closes, everything is freed. */
tal_steal(master->conn, master);
io_loop(NULL, NULL);
return 0;
}
#endif