core-lightning/daemon/secrets.c
Rusty Russell 9449f387ac daemon: primitive privkey handling.
Eventually this will be in a separate process, etc.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-01-22 06:41:48 +10:30

89 lines
2.4 KiB
C

#include "bitcoin/privkey.h"
#include "bitcoin/shadouble.h"
#include "bitcoin/signature.h"
#include "lightningd.h"
#include "log.h"
#include "peer.h"
#include "secrets.h"
#include <ccan/crypto/sha256/sha256.h>
#include <ccan/mem/mem.h>
#include <ccan/noerr/noerr.h>
#include <ccan/read_write_all/read_write_all.h>
#include <ccan/short_types/short_types.h>
#include <errno.h>
#include <fcntl.h>
#include <openssl/rand.h>
#include <secp256k1.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
struct secret {
/* Secret ID of our node; public is state->id. */
struct privkey privkey;
};
void privkey_sign(struct peer *peer, const void *src, size_t len,
struct signature *sig)
{
struct sha256_double h;
sha256_double(&h, memcheck(src, len), len);
sign_hash(peer->state->secpctx,
&peer->state->secret->privkey, &h, sig);
}
void secrets_init(struct lightningd_state *state)
{
int fd;
state->secret = tal(state, struct secret);
fd = open("privkey", O_RDONLY);
if (fd < 0) {
if (errno != ENOENT)
fatal("Failed to open privkey: %s", strerror(errno));
log_unusual(state->base_log, "Creating privkey file");
do {
if (RAND_bytes(state->secret->privkey.secret,
sizeof(state->secret->privkey.secret))
!= 1)
fatal("Could not get random bytes for privkey");
} while (!pubkey_from_privkey(state->secpctx,
&state->secret->privkey,
&state->id,
SECP256K1_EC_COMPRESSED));
fd = open("privkey", O_CREAT|O_EXCL|O_WRONLY, 0400);
if (fd < 0)
fatal("Failed to create privkey file: %s",
strerror(errno));
if (!write_all(fd, state->secret->privkey.secret,
sizeof(state->secret->privkey.secret))) {
unlink_noerr("privkey");
fatal("Failed to write to privkey file: %s",
strerror(errno));
}
if (fsync(fd) != 0)
fatal("Failed to sync to privkey file: %s",
strerror(errno));
close(fd);
fd = open("privkey", O_RDONLY);
if (fd < 0)
fatal("Failed to reopen privkey: %s", strerror(errno));
}
if (!read_all(fd, state->secret->privkey.secret,
sizeof(state->secret->privkey.secret)))
fatal("Failed to read privkey: %s", strerror(errno));
close(fd);
if (!pubkey_from_privkey(state->secpctx,
&state->secret->privkey, &state->id,
SECP256K1_EC_COMPRESSED))
fatal("Invalid privkey");
log_info(state->base_log, "ID: ");
log_add_hex(state->base_log, state->id.der, pubkey_derlen(&state->id));
}