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#include <bitcoin/privkey.h>
#include <ccan/array_size/array_size.h>
#include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
#include <ccan/err/err.h>
#include <ccan/noerr/noerr.h>
#include <ccan/read_write_all/read_write_all.h>
#include <ccan/str/str.h>
#include <ccan/tal/path/path.h>
#include <ccan/tal/str/str.h>
#include <common/bech32.h>
#include <common/configdir.h>
#include <common/derive_basepoints.h>
#include <common/descriptor_checksum.h>
#include <common/hsm_encryption.h>
#include <common/node_id.h>
#include <common/type_to_string.h>
#include <common/utils.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <sys/stat.h>
#include <unistd.h>
#include <wally_bip39.h>
#define ERROR_HSM_FILE errno
#define ERROR_USAGE 2
#define ERROR_LIBSODIUM 3
#define ERROR_LIBWALLY 4
#define ERROR_KEYDERIV 5
#define ERROR_LANG_NOT_SUPPORTED 6
#define ERROR_TERM 7
static void show_usage(const char *progname)
{
printf("%s <method> [arguments]\n", progname);
printf("methods:\n");
printf(" - decrypt <path/to/hsm_secret>\n");
printf(" - encrypt <path/to/hsm_secret>\n");
printf(" - dumpcommitments <node id> <channel dbid> <depth> "
"<path/to/hsm_secret>\n");
printf(" - guesstoremote <P2WPKH address> <node id> <tries> "
"<path/to/hsm_secret>\n");
printf(" - generatehsm <path/to/new/hsm_secret>\n");
printf(" - dumponchaindescriptors <path/to/hsm_secret> [network]\n");
exit(0);
}
static bool ensure_hsm_secret_exists(int fd, const char *path)
{
const char *config_dir = path_dirname(NULL, path);
if (fsync(fd) != 0) {
close(fd);
return false;
}
if (close(fd) != 0)
return false;
fd = open(config_dir, O_RDONLY);
if (fd < 0)
return false;
if (fsync(fd) != 0) {
close(fd);
return false;
}
close(fd);
tal_free(config_dir);
return true;
}
static void get_hsm_secret(struct secret *hsm_secret,
const char *hsm_secret_path)
{
int fd;
fd = open(hsm_secret_path, O_RDONLY);
if (fd < 0)
errx(ERROR_HSM_FILE, "Could not open hsm_secret");
if (!read_all(fd, hsm_secret, sizeof(*hsm_secret)))
errx(ERROR_HSM_FILE, "Could not read hsm_secret");
close(fd);
}
/* Derive the encryption key from the password provided, and try to decrypt
* the cipher. */
static void get_encrypted_hsm_secret(struct secret *hsm_secret,
const char *hsm_secret_path,
const char *passwd)
{
int fd;
struct secret key;
struct encrypted_hsm_secret encrypted_secret;
char *err;
fd = open(hsm_secret_path, O_RDONLY);
if (fd < 0)
errx(ERROR_HSM_FILE, "Could not open hsm_secret");
if (!read_all(fd, encrypted_secret.data, ENCRYPTED_HSM_SECRET_LEN))
errx(ERROR_HSM_FILE, "Could not read encrypted hsm_secret");
err = hsm_secret_encryption_key(passwd, &key);
if (err)
errx(ERROR_LIBSODIUM, "%s", err);
if (!decrypt_hsm_secret(&key, &encrypted_secret, hsm_secret))
errx(ERROR_LIBSODIUM, "Could not retrieve the seed. Wrong password ?");
close(fd);
}
/* Taken from hsmd. */
static void get_channel_seed(struct secret *channel_seed, struct node_id *peer_id,
u64 dbid, struct secret *hsm_secret)
{
struct secret channel_base;
u8 input[sizeof(peer_id->k) + sizeof(dbid)];
/*~ Again, "per-peer" should be "per-channel", but Hysterical Raisins */
const char *info = "per-peer seed";
/*~ We use the DER encoding of the pubkey, because it's platform
* independent. Since the dbid is unique, however, it's completely
* unnecessary, but again, existing users can't be broken. */
/* FIXME: lnd has a nicer BIP32 method for deriving secrets which we
* should migrate to. */
hkdf_sha256(&channel_base, sizeof(struct secret), NULL, 0,
hsm_secret, sizeof(*hsm_secret),
/*~ Initially, we didn't support multiple channels per
* peer at all: a channel had to be completely forgotten
* before another could exist. That was slightly relaxed,
* but the phrase "peer seed" is wired into the seed
* generation here, so we need to keep it that way for
* existing clients, rather than using "channel seed". */
"peer seed", strlen("peer seed"));
memcpy(input, peer_id->k, sizeof(peer_id->k));
BUILD_ASSERT(sizeof(peer_id->k) == PUBKEY_CMPR_LEN);
/*~ For all that talk about platform-independence, note that this
* field is endian-dependent! But let's face it, little-endian won.
* In related news, we don't support EBCDIC or middle-endian. */
memcpy(input + PUBKEY_CMPR_LEN, &dbid, sizeof(dbid));
hkdf_sha256(channel_seed, sizeof(*channel_seed),
input, sizeof(input),
&channel_base, sizeof(channel_base),
info, strlen(info));
}
/* We detect an encrypted hsm_secret as a hsm_secret which is 73-bytes long. */
static bool hsm_secret_is_encrypted(const char *hsm_secret_path)
{
struct stat st;
if (stat(hsm_secret_path, &st) != 0)
errx(ERROR_HSM_FILE, "Could not stat hsm_secret");
if (st.st_size != 32 && st.st_size != ENCRYPTED_HSM_SECRET_LEN)
errx(ERROR_HSM_FILE, "Invalid hsm_secret (neither plaintext "
"nor encrypted).");
return st.st_size == ENCRYPTED_HSM_SECRET_LEN;
}
static int decrypt_hsm(const char *hsm_secret_path)
{
int fd;
struct secret hsm_secret;
char *passwd, *err;
const char *dir, *backup;
/* This checks the file existence, too. */
if (!hsm_secret_is_encrypted(hsm_secret_path))
errx(ERROR_USAGE, "hsm_secret is not encrypted");
printf("Enter hsm_secret password:\n");
fflush(stdout);
passwd = read_stdin_pass(&err);
if (!passwd)
errx(ERROR_TERM, "%s", err);
if (sodium_init() == -1)
errx(ERROR_LIBSODIUM,
"Could not initialize libsodium. Not enough entropy ?");
dir = path_dirname(NULL, hsm_secret_path);
backup = path_join(dir, dir, "hsm_secret.backup");
get_encrypted_hsm_secret(&hsm_secret, hsm_secret_path, passwd);
/* Once the encryption key derived, we don't need it anymore. */
if (passwd)
free(passwd);
/* Create a backup file, "just in case". */
rename(hsm_secret_path, backup);
fd = open(hsm_secret_path, O_CREAT|O_EXCL|O_WRONLY, 0400);
if (fd < 0)
errx(ERROR_HSM_FILE, "Could not open new hsm_secret");
if (!write_all(fd, &hsm_secret, sizeof(hsm_secret))) {
unlink_noerr(hsm_secret_path);
close(fd);
rename("hsm_secret.backup", hsm_secret_path);
errx(ERROR_HSM_FILE,
"Failure writing plaintext seed to hsm_secret.");
}
/* Be as paranoïd as in hsmd with the file state on disk. */
if (!ensure_hsm_secret_exists(fd, hsm_secret_path)) {
unlink_noerr(hsm_secret_path);
rename(backup, hsm_secret_path);
errx(ERROR_HSM_FILE,
"Could not ensure hsm_secret existence.");
}
unlink_noerr(backup);
tal_free(dir);
printf("Succesfully decrypted hsm_secret, be careful now :-).\n");
return 0;
}
static int encrypt_hsm(const char *hsm_secret_path)
{
int fd;
struct secret key, hsm_secret;
struct encrypted_hsm_secret encrypted_hsm_secret;
char *passwd, *passwd_confirmation, *err;
const char *dir, *backup;
/* This checks the file existence, too. */
if (hsm_secret_is_encrypted(hsm_secret_path))
errx(ERROR_USAGE, "hsm_secret is already encrypted");
printf("Enter hsm_secret password:\n");
fflush(stdout);
passwd = read_stdin_pass(&err);
if (!passwd)
errx(ERROR_TERM, "%s", err);
printf("Confirm hsm_secret password:\n");
fflush(stdout);
passwd_confirmation = read_stdin_pass(&err);
if (!passwd_confirmation)
errx(ERROR_TERM, "%s", err);
if (!streq(passwd, passwd_confirmation))
errx(ERROR_USAGE, "Passwords confirmation mismatch.");
get_hsm_secret(&hsm_secret, hsm_secret_path);
dir = path_dirname(NULL, hsm_secret_path);
backup = path_join(dir, dir, "hsm_secret.backup");
if (sodium_init() == -1)
errx(ERROR_LIBSODIUM,
"Could not initialize libsodium. Not enough entropy ?");
/* Derive the encryption key from the password provided, and try to encrypt
* the seed. */
err = hsm_secret_encryption_key(passwd, &key);
if (err)
errx(ERROR_LIBSODIUM, "%s", err);
if (!encrypt_hsm_secret(&key, &hsm_secret, &encrypted_hsm_secret))
errx(ERROR_LIBSODIUM, "Could not encrypt the hsm_secret seed.");
/* Once the encryption key derived, we don't need it anymore. */
free(passwd);
free(passwd_confirmation);
/* Create a backup file, "just in case". */
rename(hsm_secret_path, backup);
fd = open(hsm_secret_path, O_CREAT|O_EXCL|O_WRONLY, 0400);
if (fd < 0)
errx(ERROR_HSM_FILE, "Could not open new hsm_secret");
/* Write the encrypted hsm_secret. */
if (!write_all(fd, encrypted_hsm_secret.data,
sizeof(encrypted_hsm_secret.data))) {
unlink_noerr(hsm_secret_path);
close(fd);
rename(backup, hsm_secret_path);
errx(ERROR_HSM_FILE, "Failure writing cipher to hsm_secret.");
}
/* Be as paranoïd as in hsmd with the file state on disk. */
if (!ensure_hsm_secret_exists(fd, hsm_secret_path)) {
unlink_noerr(hsm_secret_path);
rename(backup, hsm_secret_path);
errx(ERROR_HSM_FILE, "Could not ensure hsm_secret existence.");
}
unlink_noerr(backup);
tal_free(dir);
printf("Succesfully encrypted hsm_secret. You'll now have to pass the "
"--encrypted-hsm startup option.\n");
return 0;
}
static int dump_commitments_infos(struct node_id *node_id, u64 channel_id,
u64 depth, char *hsm_secret_path)
{
struct sha256 shaseed;
struct secret hsm_secret, channel_seed, per_commitment_secret;
struct pubkey per_commitment_point;
char *passwd, *err;
secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
| SECP256K1_CONTEXT_SIGN);
/* This checks the file existence, too. */
if (hsm_secret_is_encrypted(hsm_secret_path)) {
printf("Enter hsm_secret password:\n");
fflush(stdout);
passwd = read_stdin_pass(&err);
if (!passwd)
errx(ERROR_TERM, "%s", err);
get_encrypted_hsm_secret(&hsm_secret, hsm_secret_path, passwd);
free(passwd);
} else
get_hsm_secret(&hsm_secret, hsm_secret_path);
get_channel_seed(&channel_seed, node_id, channel_id, &hsm_secret);
derive_shaseed(&channel_seed, &shaseed);
printf("shaseed: %s\n", type_to_string(tmpctx, struct sha256, &shaseed));
for (u64 i = 0; i < depth; i++) {
if (!per_commit_secret(&shaseed, &per_commitment_secret, i))
errx(ERROR_KEYDERIV, "Could not derive secret #%"PRIu64, i);
printf("commit secret #%"PRIu64": %s\n",
i, tal_hexstr(tmpctx, per_commitment_secret.data,
sizeof(per_commitment_secret.data)));
if (!per_commit_point(&shaseed, &per_commitment_point, i))
errx(ERROR_KEYDERIV, "Could not derive point #%"PRIu64, i);
printf("commit point #%"PRIu64": %s\n",
i, type_to_string(tmpctx, struct pubkey, &per_commitment_point));
}
return 0;
}
/* In case of an unilateral close from the remote side while we suffered a
* loss of data, this tries to recover the private key from the `to_remote`
* output.
* This basically iterates over every `dbid` to derive the channel_seed and
* then derives the payment basepoint to compare to the pubkey hash specified
* in the witness programm.
* Note that since a node generates the key for the to_remote output from its
* *local* per_commitment_point, there is nothing we can do if
* `option_static_remotekey` was not negotiated.
*
* :param address: The bech32 address of the v0 P2WPKH witness programm
* :param node_id: The id of the node with which the channel was established
* :param tries: How many dbids to try.
* :param hsm_secret_path: The path to the hsm_secret
* :param passwd: The *optional* hsm_secret password
*/
static int guess_to_remote(const char *address, struct node_id *node_id,
u64 tries, char *hsm_secret_path)
{
struct secret hsm_secret, channel_seed, basepoint_secret;
char *passwd, *err;
struct pubkey basepoint;
struct ripemd160 pubkeyhash;
/* We only support P2WPKH, hence 20. */
u8 goal_pubkeyhash[20];
/* See common/bech32.h for buffer size. */
char hrp[strlen(address) - 6];
int witver;
size_t witlen;
/* Get the hrp to accept addresses from any network. */
if (bech32_decode(hrp, goal_pubkeyhash, &witlen, address, 90) != 1)
errx(ERROR_USAGE, "Could not get address' network");
if (segwit_addr_decode(&witver, goal_pubkeyhash, &witlen, hrp, address) != 1)
errx(ERROR_USAGE, "Wrong bech32 address");
secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
| SECP256K1_CONTEXT_SIGN);
/* This checks the file existence, too. */
if (hsm_secret_is_encrypted(hsm_secret_path)) {
printf("Enter hsm_secret password:\n");
fflush(stdout);
passwd = read_stdin_pass(&err);
if (!passwd)
errx(ERROR_TERM, "%s", err);
get_encrypted_hsm_secret(&hsm_secret, hsm_secret_path, passwd);
free(passwd);
} else
get_hsm_secret(&hsm_secret, hsm_secret_path);
for (u64 dbid = 1; dbid < tries ; dbid++) {
get_channel_seed(&channel_seed, node_id, dbid, &hsm_secret);
if (!derive_payment_basepoint(&channel_seed,
&basepoint, &basepoint_secret))
errx(ERROR_KEYDERIV, "Could not derive basepoints for dbid %"PRIu64
" and channel seed %s.", dbid,
type_to_string(tmpctx,
struct secret, &channel_seed));
pubkey_to_hash160(&basepoint, &pubkeyhash);
if (memcmp(pubkeyhash.u.u8, goal_pubkeyhash, 20) == 0) {
printf("bech32 : %s\n", address);
printf("pubkey hash : %s\n",
tal_hexstr(tmpctx, pubkeyhash.u.u8, 20));
printf("pubkey : %s \n",
type_to_string(tmpctx, struct pubkey, &basepoint));
printf("privkey : %s \n",
type_to_string(tmpctx, struct secret, &basepoint_secret));
return 0;
}
}
printf("Could not find any basepoint matching the provided witness programm.\n"
"Are you sure that the channel used `option_static_remotekey` ?\n");
return 1;
}
static void get_words(struct words **words) {
struct wordlist_lang {
char *abbr;
char *name;
};
struct wordlist_lang languages[] = {
{"en", "English"},
{"es", "Spanish"},
{"fr", "French"},
{"it", "Italian"},
{"jp", "Japanese"},
{"zhs", "Chinese Simplified"},
{"zht", "Chinese Traditional"},
};
printf("Select your language:\n");
for (size_t i = 0; i < ARRAY_SIZE(languages); i++) {
printf(" %zu) %s (%s)\n", i, languages[i].name, languages[i].abbr);
}
printf("Select [0-%zu]: ", ARRAY_SIZE(languages));
fflush(stdout);
char *selected = NULL;
size_t size = 0;
size_t characters = getline(&selected, &size, stdin);
if (characters < 0)
errx(ERROR_USAGE, "Could not read line from stdin.");
/* To distinguish success/failure after call */
errno = 0;
char *endptr;
long val = strtol(selected, &endptr, 10);
if (errno == ERANGE || (errno != 0 && val == 0) || endptr == selected || val < 0 || val >= ARRAY_SIZE(languages))
errx(ERROR_USAGE, "Invalid language selection, select one from the list [0-6].");
bip39_get_wordlist(languages[val].abbr, words);
}
static void get_mnemonic(char *mnemonic) {
char *line = NULL;
size_t line_size = 0;
printf("Introduce your BIP39 word list separated by space:\n");
fflush(stdout);
size_t characters = getline(&line, &line_size, stdin);
if (characters < 0)
errx(ERROR_USAGE, "Could not read line from stdin.");
line[characters-1] = '\0';
strcpy(mnemonic, line);
free(line);
}
static void read_mnemonic(char *mnemonic) {
/* Get words for the mnemonic language */
struct words *words;
get_words(&words);
/* Get mnemonic */
get_mnemonic(mnemonic);
if (bip39_mnemonic_validate(words, mnemonic) != 0) {
errx(ERROR_USAGE, "Invalid mnemonic: \"%s\"", mnemonic);
}
}
static int generate_hsm(const char *hsm_secret_path)
{
char mnemonic[BIP39_WORDLIST_LEN];
char *passphrase, *err;
read_mnemonic(mnemonic);
printf("Warning: remember that different passphrases yield different "
"bitcoin wallets.\n");
printf("If left empty, no password is used (echo is disabled).\n");
printf("Enter your passphrase: \n");
fflush(stdout);
passphrase = read_stdin_pass(&err);
if (!passphrase)
errx(ERROR_TERM, "%s", err);
if (strlen(passphrase) == 0) {
free(passphrase);
passphrase = NULL;
}
u8 bip32_seed[BIP39_SEED_LEN_512];
size_t bip32_seed_len;
if (bip39_mnemonic_to_seed(mnemonic, passphrase, bip32_seed, sizeof(bip32_seed), &bip32_seed_len) != WALLY_OK)
errx(ERROR_LIBWALLY, "Unable to derive BIP32 seed from BIP39 mnemonic");
int fd = open(hsm_secret_path, O_CREAT|O_EXCL|O_WRONLY, 0400);
if (fd < 0) {
errx(ERROR_USAGE, "Unable to create hsm_secret file");
}
/* Write only the first 32 bytes, length of the (plaintext) seed in the
* hsm_secret. */
if (!write_all(fd, bip32_seed, 32))
errx(ERROR_USAGE, "Error writing secret to hsm_secret file");
if (fsync(fd) != 0)
errx(ERROR_USAGE, "Error fsyncing hsm_secret file");
/* This should never fail if fsync succeeded. But paranoia is good, and bugs exist */
if (close(fd) != 0)
errx(ERROR_USAGE, "Error closing hsm_secret file");
printf("New hsm_secret file created at %s\n", hsm_secret_path);
printf("Use the `encrypt` command to encrypt the BIP32 seed if needed\n");
free(passphrase);
return 0;
}
static int dumponchaindescriptors(const char *hsm_secret_path, const char *old_passwd UNUSED,
const bool is_testnet)
{
struct secret hsm_secret;
char *passwd, *err;
u8 bip32_seed[BIP32_ENTROPY_LEN_256];
u32 salt = 0;
u32 version = is_testnet ?
BIP32_VER_TEST_PRIVATE : BIP32_VER_MAIN_PRIVATE;
struct ext_key master_extkey;
char *enc_xpub, *descriptor;
struct descriptor_checksum checksum;
/* This checks the file existence, too. */
if (hsm_secret_is_encrypted(hsm_secret_path)) {
printf("Enter hsm_secret password:\n");
fflush(stdout);
passwd = read_stdin_pass(&err);
if (!passwd)
errx(ERROR_TERM, "%s", err);
get_encrypted_hsm_secret(&hsm_secret, hsm_secret_path, passwd);
free(passwd);
} else
get_hsm_secret(&hsm_secret, hsm_secret_path);
/* We use m/0/0/k as the derivation tree for onchain funds. */
/* The root seed is derived from hsm_secret using hkdf.. */
do {
hkdf_sha256(bip32_seed, sizeof(bip32_seed),
&salt, sizeof(salt),
&hsm_secret, sizeof(hsm_secret),
"bip32 seed", strlen("bip32 seed"));
salt++;
/* ..Which is used to derive m/ */
} while (bip32_key_from_seed(bip32_seed, sizeof(bip32_seed),
version, 0, &master_extkey) != WALLY_OK);
if (bip32_key_to_base58(&master_extkey, BIP32_FLAG_KEY_PUBLIC, &enc_xpub) != WALLY_OK)
errx(ERROR_LIBWALLY, "Can't encode xpub");
/* Now we format the descriptor strings (we only ever create P2WPKH and
* P2SH-P2WPKH outputs). */
descriptor = tal_fmt(NULL, "wpkh(%s/0/0/*)", enc_xpub);
if (!descriptor_checksum(descriptor, strlen(descriptor), &checksum))
errx(ERROR_LIBWALLY, "Can't derive descriptor checksum for wpkh");
printf("%s#%s\n", descriptor, checksum.csum);
tal_free(descriptor);
descriptor = tal_fmt(NULL, "sh(wpkh(%s/0/0/*))", enc_xpub);
if (!descriptor_checksum(descriptor, strlen(descriptor), &checksum))
errx(ERROR_LIBWALLY, "Can't derive descriptor checksum for sh(wpkh)");
printf("%s#%s\n", descriptor, checksum.csum);
tal_free(descriptor);
wally_free_string(enc_xpub);
return 0;
}
int main(int argc, char *argv[])
{
const char *method;
setup_locale();
err_set_progname(argv[0]);
method = argc > 1 ? argv[1] : NULL;
if (!method)
show_usage(argv[0]);
if (streq(method, "decrypt")) {
if (argc < 3)
show_usage(argv[0]);
return decrypt_hsm(argv[2]);
}
if (streq(method, "encrypt")) {
if (argc < 3)
show_usage(argv[0]);
return encrypt_hsm(argv[2]);
}
if (streq(method, "dumpcommitments")) {
/* node_id channel_id depth hsm_secret */
if (argc < 6)
show_usage(argv[0]);
struct node_id node_id;
if (!node_id_from_hexstr(argv[2], strlen(argv[2]), &node_id))
errx(ERROR_USAGE, "Bad node id");
return dump_commitments_infos(&node_id, atol(argv[3]), atol(argv[4]),
argv[5]);
}
if (streq(method, "guesstoremote")) {
/* address node_id depth hsm_secret */
if (argc < 6)
show_usage(argv[0]);
struct node_id node_id;
if (!node_id_from_hexstr(argv[3], strlen(argv[3]), &node_id))
errx(ERROR_USAGE, "Bad node id");
return guess_to_remote(argv[2], &node_id, atol(argv[4]),
argv[5]);
}
if (streq(method, "generatehsm")) {
if (argc != 3)
show_usage(argv[0]);
char *hsm_secret_path = argv[2];
/* if hsm_secret already exists we abort the process
* we do not want to lose someone else's funds */
struct stat st;
if (stat(hsm_secret_path, &st) == 0)
errx(ERROR_USAGE, "hsm_secret file at %s already exists", hsm_secret_path);
return generate_hsm(hsm_secret_path);
}
if (streq(method, "dumponchaindescriptors")) {
char *net = NULL;
bool is_testnet;
if (argc < 3)
show_usage(argv[0]);
if (argc > 3)
net = argv[3];
/* Previously, we accepted hsm_secret passwords on the command line.
* This shifted the location of the network parameter.
* TODO: remove this 3 releases after v0.9.3 */
if (deprecated_apis && argc > 4)
net = argv[4];
if (net && streq(net, "testnet"))
is_testnet = true;
else if (net && !streq(net, "bitcoin"))
errx(ERROR_USAGE, "Network '%s' not supported."
" Supported networks: bitcoin (default),"
" testnet", net);
else
is_testnet = false;
return dumponchaindescriptors(argv[2], NULL, is_testnet);
}
show_usage(argv[0]);
}