kore/src/keymgr.c

/*
 * Copyright (c) 2017-2019 Joris Vink <joris@coders.se>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * The kore keymgr process is responsible for managing certificates
 * and their matching private keys.
 *
 * It is the only process in Kore that holds the private keys (the workers
 * do not have a copy of them in memory).
 *
 * When a worker requires the private key for signing it will send a message
 * to the keymgr with the to-be-signed data (KORE_MSG_KEYMGR_REQ). The keymgr
 * will perform the signing and respond with a KORE_MSG_KEYMGR_RESP message.
 *
 * The keymgr can transparently reload the private keys and certificates
 * for a configured domain when it receives a SIGUSR1. It it reloads them
 * it will send the newly loaded certificate chains to the worker processes
 * which will update their TLS contexts accordingly.
 *
 * If ACME is turned on the keymgr will also hold all account and domain
 * keys and will initiate the process of acquiring new certificates against
 * the ACME provider that is configured if those certificates do not exist
 * or are expired (or are expiring soon).
 */

#include <sys/types.h>
#include <sys/stat.h>

#include <openssl/evp.h>
#include <openssl/rsa.h>
#include <openssl/rand.h>
#include <openssl/sha.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <signal.h>
#include <unistd.h>

#include "kore.h"

#if defined(KORE_USE_ACME)
#include "acme.h"
#endif

#define RAND_TMP_FILE		"rnd.tmp"
#define RAND_POLL_INTERVAL	(1800 * 1000)
#define RAND_FILE_SIZE		1024

#if defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER >= 0x3000000fL
#undef OPENSSL_VERSION_NUMBER
#define OPENSSL_VERSION_NUMBER 0x10100000L
#endif

#if defined(__linux__)
#include "seccomp.h"

/* The syscalls our keymgr is allowed to perform, only. */
static struct sock_filter filter_keymgr[] = {
	/* Required to deal with private keys and certs. */
	KORE_SYSCALL_ALLOW(open),
	KORE_SYSCALL_ALLOW(read),
	KORE_SYSCALL_ALLOW(write),
	KORE_SYSCALL_ALLOW(close),
	KORE_SYSCALL_ALLOW(fstat),
	KORE_SYSCALL_ALLOW(futex),
	KORE_SYSCALL_ALLOW(writev),
	KORE_SYSCALL_ALLOW(openat),

	/* Net related. */
	KORE_SYSCALL_ALLOW(poll),
	KORE_SYSCALL_ALLOW(sendto),
	KORE_SYSCALL_ALLOW(recvfrom),
	KORE_SYSCALL_ALLOW(epoll_wait),
	KORE_SYSCALL_ALLOW(epoll_pwait),

	/* Process things. */
	KORE_SYSCALL_ALLOW(exit),
	KORE_SYSCALL_ALLOW(kill),
	KORE_SYSCALL_ALLOW(getuid),
	KORE_SYSCALL_ALLOW(getpid),
	KORE_SYSCALL_ALLOW(arch_prctl),
	KORE_SYSCALL_ALLOW(exit_group),
	KORE_SYSCALL_ALLOW(sigaltstack),
	KORE_SYSCALL_ALLOW(rt_sigreturn),
	KORE_SYSCALL_ALLOW(rt_sigaction),
	KORE_SYSCALL_ALLOW(rt_sigprocmask),

	/* Other things. */
	KORE_SYSCALL_ALLOW(brk),
	KORE_SYSCALL_ALLOW(mmap),
	KORE_SYSCALL_ALLOW(munmap),
	KORE_SYSCALL_ALLOW(clock_gettime),
#if defined(__NR_getrandom)
	KORE_SYSCALL_ALLOW(getrandom),
#endif
};
#endif

struct key {
	EVP_PKEY		*pkey;
	struct kore_domain	*dom;
	TAILQ_ENTRY(key)	list;
};

char				*rand_file = NULL;

static TAILQ_HEAD(, key)	keys;
static int			initialized = 0;

#if defined(KORE_USE_ACME)

#define ACME_ORDER_STATE_INIT		1
#define ACME_ORDER_STATE_SUBMIT		2
#define ACME_ORDER_STATE_PENDING	3

#define ACME_X509_EXPIRATION		120
#define ACME_TLS_ALPN_01_OID		"1.3.6.1.5.5.7.1.31"

/* Set to 1 when we receive KORE_ACME_PROC_READY. */
static int		acmeproc_ready = 0;

struct acme_order {
	int			state;
	struct kore_timer	*timer;
	char			*domain;
};

static char	*keymgr_bignum_base64(const BIGNUM *);

static void	keymgr_acme_init(void);
static void	keymgr_acme_sign(struct kore_msg *, const void *);
static void	keymgr_acme_ready(struct kore_msg *, const void *);
static void	keymgr_acme_domainkey(struct kore_domain *, struct key *);

static void	keymgr_acme_order_create(const char *);
static void	keymgr_acme_order_status(void *, u_int64_t);

static void	keymgr_x509_ext(X509 *, int, const char *, ...);
static void	keymgr_acme_challenge_cert(const void *, size_t, struct key *);

#endif /* KORE_USE_ACME */

static void	keymgr_reload(void);
static void	keymgr_load_randfile(void);
static void	keymgr_save_randfile(void);

static struct key	*keymgr_load_privatekey(const char *);
static void		keymgr_load_domain_privatekey(struct kore_domain *);

static void	keymgr_msg_recv(struct kore_msg *, const void *);
static void	keymgr_entropy_request(struct kore_msg *, const void *);
static void	keymgr_certificate_request(struct kore_msg *, const void *);
static void	keymgr_submit_certificates(struct kore_domain *, u_int16_t);
static void	keymgr_submit_file(u_int8_t, struct kore_domain *,
		    const char *, u_int16_t, int);

static void	keymgr_rsa_encrypt(struct kore_msg *, const void *,
		    struct key *);
static void	keymgr_ecdsa_sign(struct kore_msg *, const void *,
		    struct key *);

int	keymgr_active = 0;
char	*keymgr_root_path = NULL;
char	*keymgr_runas_user = NULL;

void
kore_keymgr_run(void)
{
	int		quit;
	u_int64_t	now, netwait, last_seed;

	if (keymgr_active == 0)
		fatalx("%s: called with keymgr_active == 0", __func__);

	quit = 0;

	kore_server_closeall();
	kore_module_cleanup();

	net_init();
	kore_timer_init();
	kore_connection_init();
	kore_platform_event_init();

	kore_msg_worker_init();
	kore_msg_register(KORE_MSG_KEYMGR_REQ, keymgr_msg_recv);
	kore_msg_register(KORE_MSG_ENTROPY_REQ, keymgr_entropy_request);
	kore_msg_register(KORE_MSG_CERTIFICATE_REQ, keymgr_certificate_request);

#if defined(__linux__)
	/* Drop all enabled seccomp filters, and add only ours. */
	kore_seccomp_drop();
	kore_seccomp_filter("keymgr", filter_keymgr,
	    KORE_FILTER_LEN(filter_keymgr));
#endif
#if defined(KORE_USE_PYTHON)
	kore_msg_unregister(KORE_PYTHON_SEND_OBJ);
#endif
	kore_worker_privdrop(keymgr_runas_user, keymgr_root_path);

	if (!kore_quiet)
		kore_log(LOG_NOTICE, "key manager started (pid#%d)", getpid());

	if (rand_file != NULL) {
		keymgr_load_randfile();
		keymgr_save_randfile();
	} else if (!kore_quiet) {
		kore_log(LOG_WARNING, "no rand_file location specified");
	}

	RAND_poll();
	last_seed = 0;

	initialized = 1;
	keymgr_reload();

#if defined(__OpenBSD__)
	if (pledge("stdio rpath", NULL) == -1)
		fatalx("failed to pledge keymgr process");
#endif

	while (quit != 1) {
		now = kore_time_ms();
		if ((now - last_seed) > RAND_POLL_INTERVAL) {
			RAND_poll();
			last_seed = now;
		}

		netwait = kore_timer_next_run(now);
		kore_platform_event_wait(netwait);

		if (sig_recv != 0) {
			switch (sig_recv) {
			case SIGQUIT:
			case SIGINT:
			case SIGTERM:
				quit = 1;
				break;
			case SIGUSR1:
				keymgr_reload();
				break;
			default:
				break;
			}
			sig_recv = 0;
		}

		if (quit)
			break;

		now = kore_time_ms();
		kore_timer_run(now);
		kore_connection_prune(KORE_CONNECTION_PRUNE_DISCONNECT);
	}

	kore_keymgr_cleanup(1);
	kore_platform_event_cleanup();
	kore_connection_cleanup();
	net_cleanup();
}

void
kore_keymgr_cleanup(int final)
{
	struct key		*key, *next;

	if (final && !kore_quiet)
		kore_log(LOG_NOTICE, "cleaning up keys");

	if (initialized == 0)
		return;

	for (key = TAILQ_FIRST(&keys); key != NULL; key = next) {
		next = TAILQ_NEXT(key, list);
		TAILQ_REMOVE(&keys, key, list);

		EVP_PKEY_free(key->pkey);
		kore_free(key);
	}
}

static void
keymgr_reload(void)
{
	struct kore_server	*srv;
	struct kore_domain	*dom;

	if (!kore_quiet)
		kore_log(LOG_INFO, "(re)loading certificates, keys and CRLs");

	kore_keymgr_cleanup(0);
	TAILQ_INIT(&keys);

#if defined(KORE_USE_ACME)
	keymgr_acme_init();
#endif

	kore_domain_callback(keymgr_load_domain_privatekey);

	/* can't use kore_domain_callback() due to dst parameter. */
	LIST_FOREACH(srv, &kore_servers, list) {
		if (srv->tls == 0)
			continue;
		TAILQ_FOREACH(dom, &srv->domains, list)
			keymgr_submit_certificates(dom, KORE_MSG_WORKER_ALL);
	}
}

static void
keymgr_submit_certificates(struct kore_domain *dom, u_int16_t dst)
{
	if (access(dom->certfile, R_OK) == -1) {
#if defined(KORE_USE_ACME)
		if (dom->acme && errno == ENOENT) {
			keymgr_acme_order_create(dom->domain);
			return;
		}
#endif
		fatalx("cannot read '%s' for %s: %s",
		    dom->certfile, dom->domain, errno_s);
	}

	keymgr_acme_order_create(dom->domain);
	printf("sending %s\n", dom->certfile);
	keymgr_submit_file(KORE_MSG_CERTIFICATE, dom, dom->certfile, dst, 0);

	if (dom->crlfile != NULL)
		keymgr_submit_file(KORE_MSG_CRL, dom, dom->crlfile, dst, 1);
}

static void
keymgr_submit_file(u_int8_t id, struct kore_domain *dom,
    const char *file, u_int16_t dst, int can_fail)
{
	int				fd;
	struct stat			st;
	ssize_t				ret;
	size_t				len;
	struct kore_x509_msg		*msg;
	u_int8_t			*payload;

	if ((fd = open(file, O_RDONLY)) == -1) {
		if (errno == ENOENT && can_fail)
			return;
		fatalx("open(%s): %s", file, errno_s);
	}

	if (fstat(fd, &st) == -1)
		fatalx("stat(%s): %s", file, errno_s);

	if (!S_ISREG(st.st_mode))
		fatalx("%s is not a file", file);

	if (st.st_size <= 0 || st.st_size > (1024 * 1024 * 10)) {
		fatalx("%s length is not valid (%jd)", file,
		    (intmax_t)st.st_size);
	}

	len = sizeof(*msg) + st.st_size;
	payload = kore_calloc(1, len);

	msg = (struct kore_x509_msg *)payload;

	if (kore_strlcpy(msg->domain, dom->domain, sizeof(msg->domain)) >=
	    sizeof(msg->domain))
		fatalx("%s: domain truncated", __func__);

	msg->data_len = st.st_size;
	ret = read(fd, &msg->data[0], msg->data_len);
	if (ret == -1)
		fatalx("failed to read from %s: %s", file, errno_s);
	if (ret == 0)
		fatalx("eof while reading %s", file);

	if ((size_t)ret != msg->data_len) {
		fatalx("bad read on %s: expected %zu, got %zd",
		    file, msg->data_len, ret);
	}

	kore_msg_send(dst, id, payload, len);
	kore_free(payload);
	close(fd);
}

static void
keymgr_load_randfile(void)
{
	int		fd;
	struct stat	st;
	ssize_t		ret;
	size_t		total;
	u_int8_t	buf[RAND_FILE_SIZE];

	if (rand_file == NULL)
		return;

	if ((fd = open(rand_file, O_RDONLY)) == -1)
		fatalx("open(%s): %s", rand_file, errno_s);

	if (fstat(fd, &st) == -1)
		fatalx("stat(%s): %s", rand_file, errno_s);
	if (!S_ISREG(st.st_mode))
		fatalx("%s is not a file", rand_file);
	if (st.st_size != RAND_FILE_SIZE)
		fatalx("%s has an invalid size", rand_file);

	total = 0;

	while (total != RAND_FILE_SIZE) {
		ret = read(fd, buf, sizeof(buf));
		if (ret == 0)
			fatalx("EOF on %s", rand_file);

		if (ret == -1) {
			if (errno == EINTR)
				continue;
			fatalx("read(%s): %s", rand_file, errno_s);
		}

		total += (size_t)ret;
		RAND_seed(buf, (int)ret);
		OPENSSL_cleanse(buf, sizeof(buf));
	}

	(void)close(fd);
	if (unlink(rand_file) == -1) {
		kore_log(LOG_WARNING, "failed to unlink %s: %s",
		    rand_file, errno_s);
	}
}

static void
keymgr_save_randfile(void)
{
	int		fd;
	struct stat	st;
	ssize_t		ret;
	u_int8_t	buf[RAND_FILE_SIZE];

	if (rand_file == NULL)
		return;

	if (stat(RAND_TMP_FILE, &st) != -1) {
		kore_log(LOG_WARNING, "removing stale %s file", RAND_TMP_FILE);
		(void)unlink(RAND_TMP_FILE);
	}

	if (RAND_bytes(buf, sizeof(buf)) != 1) {
		kore_log(LOG_WARNING, "RAND_bytes: %s", ssl_errno_s);
		goto cleanup;
	}

	if ((fd = open(RAND_TMP_FILE,
	    O_CREAT | O_TRUNC | O_WRONLY, 0400)) == -1) {
		kore_log(LOG_WARNING,
		    "failed to open %s: %s - random data not written",
		    RAND_TMP_FILE, errno_s);
		goto cleanup;
	}

	ret = write(fd, buf, sizeof(buf));
	if (ret == -1 || (size_t)ret != sizeof(buf)) {
		kore_log(LOG_WARNING, "failed to write random data");
		(void)close(fd);
		(void)unlink(RAND_TMP_FILE);
		goto cleanup;
	}

	if (close(fd) == -1)
		kore_log(LOG_WARNING, "close(%s): %s", RAND_TMP_FILE, errno_s);

	if (rename(RAND_TMP_FILE, rand_file) == -1) {
		kore_log(LOG_WARNING, "rename(%s, %s): %s",
		    RAND_TMP_FILE, rand_file, errno_s);
		(void)unlink(rand_file);
		(void)unlink(RAND_TMP_FILE);
	}

cleanup:
	OPENSSL_cleanse(buf, sizeof(buf));
}

static void
keymgr_load_domain_privatekey(struct kore_domain *dom)
{
	struct key	*key;

	if (dom->server->tls == 0)
		return;

	key = keymgr_load_privatekey(dom->certkey);

	if (key->pkey == NULL) {
#if defined(KORE_USE_ACME)
		if (dom->acme)
			keymgr_acme_domainkey(dom, key);
#endif
		if (key->pkey == NULL) {
			fatalx("failed to load private key for '%s' (%s)",
			    dom->domain, errno_s);
		}
	}

	key->dom = dom;

	kore_log(LOG_INFO, "loaded private key for '%s'", dom->domain);
}

static struct key *
keymgr_load_privatekey(const char *path)
{
	struct key		*key;

	key = kore_calloc(1, sizeof(*key));
	TAILQ_INSERT_TAIL(&keys, key, list);

	/* Caller should check if pkey was loaded. */
	if (path)
		key->pkey = kore_rsakey_load(path);

	return (key);
}

static void
keymgr_certificate_request(struct kore_msg *msg, const void *data)
{
	struct kore_server	*srv;
	struct kore_domain	*dom;

	LIST_FOREACH(srv, &kore_servers, list) {
		if (srv->tls == 0)
			continue;
		TAILQ_FOREACH(dom, &srv->domains, list)
			keymgr_submit_certificates(dom, msg->src);
	}
}

static void
keymgr_entropy_request(struct kore_msg *msg, const void *data)
{
	u_int8_t	buf[RAND_FILE_SIZE];

	if (RAND_bytes(buf, sizeof(buf)) != 1) {
		kore_log(LOG_WARNING,
		    "failed to generate entropy for worker %u: %s",
		    msg->src, ssl_errno_s);
		return;
	}

	/* No cleanse, this stuff is leaked in the kernel path anyway. */
	kore_msg_send(msg->src, KORE_MSG_ENTROPY_RESP, buf, sizeof(buf));
}

static void
keymgr_msg_recv(struct kore_msg *msg, const void *data)
{
	const struct kore_keyreq	*req;
	struct key			*key;

	if (msg->length < sizeof(*req))
		return;

	req = (const struct kore_keyreq *)data;

	if (msg->length != (sizeof(*req) + req->data_len))
		return;

	if (req->domain[KORE_DOMAINNAME_LEN] != '\0')
		return;

	key = NULL;
	TAILQ_FOREACH(key, &keys, list) {
		if (key->dom == NULL)
			continue;
		if (!strcmp(key->dom->domain, req->domain))
			break;
	}

	if (key == NULL)
		return;

	switch (msg->id) {
	case KORE_MSG_KEYMGR_REQ:
		switch (EVP_PKEY_id(key->pkey)) {
		case EVP_PKEY_RSA:
			keymgr_rsa_encrypt(msg, data, key);
			break;
		case EVP_PKEY_EC:
			keymgr_ecdsa_sign(msg, data, key);
			break;
		default:
			break;
		}
		break;
#if defined(KORE_USE_ACME)
	case KORE_ACME_CHALLENGE_CERT:
		keymgr_acme_challenge_cert(req->data, req->data_len, key);
		break;
#endif
	}
}

static void
keymgr_rsa_encrypt(struct kore_msg *msg, const void *data, struct key *key)
{
	int				ret;
	RSA				*rsa;
	const struct kore_keyreq	*req;
	size_t				keylen;
	u_int8_t			buf[1024];

	req = (const struct kore_keyreq *)data;

#if defined(KORE_OPENSSL_NEWER_API)
	rsa = EVP_PKEY_get0_RSA(key->pkey);
#else
	rsa = key->pkey->pkey.rsa;
#endif
	keylen = RSA_size(rsa);
	if (req->data_len > keylen || keylen > sizeof(buf))
		return;

	ret = RSA_private_encrypt(req->data_len, req->data,
	    buf, rsa, req->padding);
	if (ret != RSA_size(rsa))
		return;

	kore_msg_send(msg->src, KORE_MSG_KEYMGR_RESP, buf, ret);
}

static void
keymgr_ecdsa_sign(struct kore_msg *msg, const void *data, struct key *key)
{
	size_t				len;
	EC_KEY				*ec;
	const struct kore_keyreq	*req;
	unsigned int			siglen;
	u_int8_t			sig[1024];

	req = (const struct kore_keyreq *)data;
#if defined(KORE_OPENSSL_NEWER_API)
	ec = EVP_PKEY_get0_EC_KEY(key->pkey);
#else
	ec = key->pkey->pkey.ec;
#endif
	len = ECDSA_size(ec);
	if (req->data_len > len || len > sizeof(sig))
		return;

	if (ECDSA_sign(EVP_PKEY_NONE, req->data, req->data_len,
	    sig, &siglen, ec) == 0)
		return;

	if (siglen > sizeof(sig))
		return;

	kore_msg_send(msg->src, KORE_MSG_KEYMGR_RESP, sig, siglen);
}

#if defined(KORE_USE_ACME)
static void
keymgr_acme_init(void)
{
	RSA		*rsa;
	struct key	*key;
	char		*e, *n;
	int		needsreg;
	const BIGNUM	*be, *bn;

	if (acme_provider == NULL)
		return;

	if (mkdir(KORE_ACME_CERTDIR, 0700) == -1) {
		if (errno != EEXIST)
			fatalx("mkdir(%s): %s", KORE_ACME_CERTDIR, errno_s);
	}

	umask(S_IWGRP | S_IWOTH | S_IRGRP | S_IROTH);

	needsreg = 0;
	key = keymgr_load_privatekey(KORE_ACME_ACCOUNT_KEY);

	if (key->pkey == NULL) {
		kore_log(LOG_NOTICE, "generating new ACME account key");
		key->pkey = kore_rsakey_generate(KORE_ACME_ACCOUNT_KEY);
		needsreg = 1;
	} else {
		kore_log(LOG_INFO, "loaded existing ACME account key");
	}

#if OPENSSL_VERSION_NUMBER >= 0x10100000L
	rsa = EVP_PKEY_get0_RSA(key->pkey);
	be = RSA_get0_e(rsa);
	bn = RSA_get0_n(rsa);
#else
	rsa = key->pkey->pkey.rsa;
	be = rsa->e;
	bn = rsa->n;
#endif

	e = keymgr_bignum_base64(be);
	n = keymgr_bignum_base64(bn);

	kore_msg_send(KORE_WORKER_ACME, KORE_ACME_RSAKEY_E, e, strlen(e));
	kore_msg_send(KORE_WORKER_ACME, KORE_ACME_RSAKEY_N, n, strlen(n));

	kore_free(e);
	kore_free(n);

	if (needsreg) {
		kore_msg_send(KORE_WORKER_ACME,
		    KORE_ACME_ACCOUNT_CREATE, NULL, 0);
	} else {
		kore_msg_send(KORE_WORKER_ACME,
		    KORE_ACME_ACCOUNT_RESOLVE, NULL, 0);
	}

	kore_msg_register(KORE_ACME_SIGN, keymgr_acme_sign);
	kore_msg_register(KORE_ACME_PROC_READY, keymgr_acme_ready);
	kore_msg_register(KORE_ACME_CHALLENGE_CERT, keymgr_msg_recv);
}

static void
keymgr_acme_domainkey(struct kore_domain *dom, struct key *key)
{
	char		*p;

	kore_log(LOG_NOTICE, "generated new domain key for %s", dom->domain);

	if ((p = strrchr(dom->certkey, '/')) == NULL)
		fatalx("invalid certkey path '%s'", dom->certkey);

	*p = '\0';

	if (mkdir(dom->certkey, 0700) == -1) {
		if (errno != EEXIST)
			fatalx("mkdir(%s): %s", dom->certkey, errno_s);
	}

	*p = '/';
	key->pkey = kore_rsakey_generate(dom->certkey);
}

static void
keymgr_acme_order_create(const char *domain)
{
	struct acme_order	*order;

	order = kore_calloc(1, sizeof(*order));

	order->state = ACME_ORDER_STATE_INIT;
	order->domain = kore_strdup(domain);
	order->timer = kore_timer_add(keymgr_acme_order_status, 5000, order, 0);
}

static void
keymgr_acme_order_status(void *udata, u_int64_t now)
{
	struct acme_order	*order = udata;

	switch (order->state) {
	case ACME_ORDER_STATE_INIT:
		if (acmeproc_ready == 0)
			return;
		order->state = ACME_ORDER_STATE_SUBMIT;
		/* fallthrough */
	case ACME_ORDER_STATE_SUBMIT:
		kore_msg_send(KORE_WORKER_ACME, KORE_ACME_ORDER_CREATE,
		    order->domain, strlen(order->domain));
		order->state = ACME_ORDER_STATE_PENDING;
		break;
	case ACME_ORDER_STATE_PENDING:
		kore_log(LOG_INFO, "order for '%s' is pending acme process",
		    order->domain);
		break;
	default:
		fatalx("%s: unknown order state %d", __func__, order->state);
	}
}

static void
keymgr_acme_ready(struct kore_msg *msg, const void *data)
{
	acmeproc_ready = 1;
	kore_log(LOG_INFO, "acme process ready to receive orders");
}

static void
keymgr_acme_sign(struct kore_msg *msg, const void *data)
{
	u_int32_t		id;
	struct kore_buf		buf;
	const u_int8_t		*ptr;
	u_int8_t		*sig;
	EVP_MD_CTX		*ctx;
	struct key		*key;
	char			*b64;
	unsigned int		siglen;

	TAILQ_FOREACH(key, &keys, list) {
		if (key->dom == NULL)
			break;
	}

	if (key == NULL)
		fatalx("%s: missing key", __func__);

	if (msg->length < sizeof(id))
		fatalx("%s: invalid length (%zu)", __func__, msg->length);

	ptr = data;
	memcpy(&id, ptr, sizeof(id));

	ptr += sizeof(id);
	msg->length -= sizeof(id);

	sig = kore_calloc(1, EVP_PKEY_size(key->pkey));

	if ((ctx = EVP_MD_CTX_create()) == NULL)
		fatalx("EVP_MD_CTX_create: %s", ssl_errno_s);

	if (!EVP_SignInit_ex(ctx, EVP_sha256(), NULL))
		fatalx("EVP_SignInit_ex: %s", ssl_errno_s);

	if (!EVP_SignUpdate(ctx, ptr, msg->length))
		fatalx("EVP_SignUpdate: %s", ssl_errno_s);

	if (!EVP_SignFinal(ctx, sig, &siglen, key->pkey))
		fatalx("EVP_SignFinal: %s", ssl_errno_s);

	if (!kore_base64url_encode(sig, siglen, &b64, KORE_BASE64_RAW))
		fatalx("%s: failed to b64url encode signed data", __func__);

	kore_buf_init(&buf, siglen + sizeof(id));
	kore_buf_append(&buf, &id, sizeof(id));
	kore_buf_append(&buf, b64, strlen(b64));

	kore_msg_send(KORE_WORKER_ACME,
	    KORE_ACME_SIGN_RESULT, buf.data, buf.offset);

	EVP_MD_CTX_destroy(ctx);

	kore_free(sig);
	kore_free(b64);
	kore_buf_cleanup(&buf);
}

static void
keymgr_acme_challenge_cert(const void *data, size_t len, struct key *key)
{
	size_t			idx;
	struct kore_x509_msg	hdr;
	struct kore_buf		buf;
	time_t			now;
	X509_NAME		*name;
	X509			*x509;
	const u_int8_t		*digest;
	int			slen, acme;
	u_int8_t		*cert, *uptr;
	char			hex[(SHA256_DIGEST_LENGTH * 2) + 1];

	kore_log(LOG_INFO, "[%s] generating tls-alpn-01 challenge cert",
	    key->dom->domain);

	if (len != SHA256_DIGEST_LENGTH)
		fatalx("invalid digest length of %zu bytes", len);

	digest = data;
	for (idx = 0; idx < len; idx++) {
		slen = snprintf(hex + (idx * 2), sizeof(hex) - (idx * 2),
		    "%02x", digest[idx]);
		if (slen == -1 || (size_t)slen >= sizeof(hex))
			fatalx("faild to convert digest to hex");
	}

	if ((x509 = X509_new()) == NULL)
		fatalx("X509_new(): %s", ssl_errno_s);

	if (!X509_set_version(x509, 2))
		fatalx("X509_set_version(): %s", ssl_errno_s);

	time(&now);
	if (!ASN1_INTEGER_set(X509_get_serialNumber(x509), now))
		fatalx("ASN1_INTEGER_set(): %s", ssl_errno_s);

	if (!X509_gmtime_adj(X509_get_notBefore(x509), 0))
		fatalx("X509_gmtime_adj(): %s", ssl_errno_s);

	if (!X509_gmtime_adj(X509_get_notAfter(x509), ACME_X509_EXPIRATION))
		fatalx("X509_gmtime_adj(): %s", ssl_errno_s);

	if (!X509_set_pubkey(x509, key->pkey))
		fatalx("X509_set_pubkey(): %s", ssl_errno_s);

	if ((name = X509_get_subject_name(x509)) == NULL)
		fatalx("X509_get_subject_name(): %s", ssl_errno_s);

	if (!X509_NAME_add_entry_by_txt(name, "CN",
	    MBSTRING_ASC, (const unsigned char *)key->dom->domain, -1, -1, 0))
		fatalx("X509_NAME_add_entry_by_txt(): CN %s", ssl_errno_s);

	if (!X509_set_issuer_name(x509, name))
		fatalx("X509_set_issuer_name(): %s", ssl_errno_s);

	acme = OBJ_create(ACME_TLS_ALPN_01_OID, "acme", "acmeIdentifier");
	X509V3_EXT_add_alias(acme, NID_subject_key_identifier);

	keymgr_x509_ext(x509, acme, "critical,%s", hex);
	keymgr_x509_ext(x509, NID_subject_alt_name, "DNS:%s", key->dom->domain);

	if (!X509_sign(x509, key->pkey, EVP_sha256()))
		fatalx("X509_sign(): %s", ssl_errno_s);

	if ((slen = i2d_X509(x509, NULL)) <= 0)
		fatalx("i2d_X509: %s", ssl_errno_s);

	cert = kore_calloc(1, slen);
	uptr = cert;

	if (i2d_X509(x509, &uptr) <= 0)
		fatalx("i2d_X509: %s", ssl_errno_s);

	memset(&hdr, 0, sizeof(hdr));
	hdr.data_len = slen;

	if (kore_strlcpy(hdr.domain, key->dom->domain, sizeof(hdr.domain)) >=
	    sizeof(hdr.domain))
		fatalx("%s: domain truncated", __func__);

	kore_buf_init(&buf, sizeof(hdr) + slen);
	kore_buf_append(&buf, &hdr, sizeof(hdr));
	kore_buf_append(&buf, cert, slen);

	kore_msg_send(KORE_MSG_WORKER_ALL, KORE_ACME_CHALLENGE_SET_CERT,
	    buf.data, buf.offset);

	kore_buf_cleanup(&buf);
	kore_free(cert);
	X509_free(x509);
}

static void
keymgr_x509_ext(X509 *x509, int extnid, const char *fmt, ...)
{
	int			len;
	X509_EXTENSION		*ext;
	va_list			args;
	char			buf[1024];

	va_start(args, fmt);
	len = vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	if (len == -1 || (size_t)len >= sizeof(buf))
		fatalx("failed to create buffer for extension %d", extnid);

	if ((ext = X509V3_EXT_conf_nid(NULL, NULL, extnid, buf)) == NULL)
		fatalx("X509V3_EXT_conf_nid: %s", ssl_errno_s);

	if (!X509_add_ext(x509, ext, -1))
		fatalx("X509_add_ext: %s", ssl_errno_s);

	X509_EXTENSION_free(ext);
}

static char *
keymgr_bignum_base64(const BIGNUM *bn)
{
	int		len;
	void		*buf;
	char		*encoded;

	len = BN_num_bytes(bn);
	buf = kore_calloc(1, len);

	if (BN_bn2bin(bn, buf) != len)
		fatalx("BN_bn2bin: %s", ssl_errno_s);

	if (!kore_base64url_encode(buf, len, &encoded, KORE_BASE64_RAW))
		fatalx("failed to base64 encode BIGNUM");

	return (encoded);
}
#endif