forked from openssh/openssh-portable
/
ssh-agent.c
1302 lines (1186 loc) · 31.4 KB
/
ssh-agent.c
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/* $OpenBSD: ssh-agent.c,v 1.228 2018/02/23 15:58:37 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* The authentication agent program.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
#endif
#ifdef HAVE_SYS_UN_H
# include <sys/un.h>
#endif
#include "openbsd-compat/sys-queue.h"
#ifdef WITH_OPENSSL
#include <openssl/evp.h>
#include "openbsd-compat/openssl-compat.h"
#endif
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#ifdef HAVE_PATHS_H
# include <paths.h>
#endif
#ifdef HAVE_POLL_H
# include <poll.h>
#endif
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_UTIL_H
# include <util.h>
#endif
#include "xmalloc.h"
#include "ssh.h"
#include "sshbuf.h"
#include "sshkey.h"
#include "authfd.h"
#include "compat.h"
#include "log.h"
#include "misc.h"
#include "digest.h"
#include "ssherr.h"
#include "match.h"
#ifdef ENABLE_PKCS11
#include "ssh-pkcs11.h"
#endif
#ifndef DEFAULT_PKCS11_WHITELIST
# define DEFAULT_PKCS11_WHITELIST "/usr/lib*/*,/usr/local/lib*/*"
#endif
/* Maximum accepted message length */
#define AGENT_MAX_LEN (256*1024)
typedef enum {
AUTH_UNUSED,
AUTH_SOCKET,
AUTH_CONNECTION
} sock_type;
typedef struct {
int fd;
sock_type type;
struct sshbuf *input;
struct sshbuf *output;
struct sshbuf *request;
} SocketEntry;
u_int sockets_alloc = 0;
SocketEntry *sockets = NULL;
typedef struct identity {
TAILQ_ENTRY(identity) next;
struct sshkey *key;
char *comment;
char *provider;
time_t death;
u_int confirm;
} Identity;
struct idtable {
int nentries;
TAILQ_HEAD(idqueue, identity) idlist;
};
/* private key table */
struct idtable *idtab;
int max_fd = 0;
/* pid of shell == parent of agent */
pid_t parent_pid = -1;
time_t parent_alive_interval = 0;
/* pid of process for which cleanup_socket is applicable */
pid_t cleanup_pid = 0;
/* pathname and directory for AUTH_SOCKET */
char socket_name[PATH_MAX];
char socket_dir[PATH_MAX];
/* PKCS#11 path whitelist */
static char *pkcs11_whitelist;
/* locking */
#define LOCK_SIZE 32
#define LOCK_SALT_SIZE 16
#define LOCK_ROUNDS 1
int locked = 0;
u_char lock_pwhash[LOCK_SIZE];
u_char lock_salt[LOCK_SALT_SIZE];
extern char *__progname;
/* Default lifetime in seconds (0 == forever) */
static long lifetime = 0;
static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
static void
close_socket(SocketEntry *e)
{
close(e->fd);
e->fd = -1;
e->type = AUTH_UNUSED;
sshbuf_free(e->input);
sshbuf_free(e->output);
sshbuf_free(e->request);
}
static void
idtab_init(void)
{
idtab = xcalloc(1, sizeof(*idtab));
TAILQ_INIT(&idtab->idlist);
idtab->nentries = 0;
}
static void
free_identity(Identity *id)
{
sshkey_free(id->key);
free(id->provider);
free(id->comment);
free(id);
}
/* return matching private key for given public key */
static Identity *
lookup_identity(struct sshkey *key)
{
Identity *id;
TAILQ_FOREACH(id, &idtab->idlist, next) {
if (sshkey_equal(key, id->key))
return (id);
}
return (NULL);
}
/* Check confirmation of keysign request */
static int
confirm_key(Identity *id)
{
char *p;
int ret = -1;
p = sshkey_fingerprint(id->key, fingerprint_hash, SSH_FP_DEFAULT);
if (p != NULL &&
ask_permission("Allow use of key %s?\nKey fingerprint %s.",
id->comment, p))
ret = 0;
free(p);
return (ret);
}
static void
send_status(SocketEntry *e, int success)
{
int r;
if ((r = sshbuf_put_u32(e->output, 1)) != 0 ||
(r = sshbuf_put_u8(e->output, success ?
SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
}
/* send list of supported public keys to 'client' */
static void
process_request_identities(SocketEntry *e)
{
Identity *id;
struct sshbuf *msg;
int r;
if ((msg = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
(r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
TAILQ_FOREACH(id, &idtab->idlist, next) {
if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
!= 0 ||
(r = sshbuf_put_cstring(msg, id->comment)) != 0) {
error("%s: put key/comment: %s", __func__,
ssh_err(r));
continue;
}
}
if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
sshbuf_free(msg);
}
static char *
agent_decode_alg(struct sshkey *key, u_int flags)
{
if (key->type == KEY_RSA) {
if (flags & SSH_AGENT_RSA_SHA2_256)
return "rsa-sha2-256";
else if (flags & SSH_AGENT_RSA_SHA2_512)
return "rsa-sha2-512";
}
return NULL;
}
/* ssh2 only */
static void
process_sign_request2(SocketEntry *e)
{
const u_char *data;
u_char *signature = NULL;
size_t dlen, slen = 0;
u_int compat = 0, flags;
int r, ok = -1;
struct sshbuf *msg;
struct sshkey *key = NULL;
struct identity *id;
if ((msg = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((r = sshkey_froms(e->request, &key)) != 0 ||
(r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
(r = sshbuf_get_u32(e->request, &flags)) != 0) {
error("%s: couldn't parse request: %s", __func__, ssh_err(r));
goto send;
}
if ((id = lookup_identity(key)) == NULL) {
verbose("%s: %s key not found", __func__, sshkey_type(key));
goto send;
}
if (id->confirm && confirm_key(id) != 0) {
verbose("%s: user refused key", __func__);
goto send;
}
if ((r = sshkey_sign(id->key, &signature, &slen,
data, dlen, agent_decode_alg(key, flags), compat)) != 0) {
error("%s: sshkey_sign: %s", __func__, ssh_err(r));
goto send;
}
/* Success */
ok = 0;
send:
sshkey_free(key);
if (ok == 0) {
if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
(r = sshbuf_put_string(msg, signature, slen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
} else if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
sshbuf_free(msg);
free(signature);
}
/* shared */
static void
process_remove_identity(SocketEntry *e)
{
int r, success = 0;
struct sshkey *key = NULL;
Identity *id;
if ((r = sshkey_froms(e->request, &key)) != 0) {
error("%s: get key: %s", __func__, ssh_err(r));
goto done;
}
if ((id = lookup_identity(key)) == NULL) {
debug("%s: key not found", __func__);
goto done;
}
/* We have this key, free it. */
if (idtab->nentries < 1)
fatal("%s: internal error: nentries %d",
__func__, idtab->nentries);
TAILQ_REMOVE(&idtab->idlist, id, next);
free_identity(id);
idtab->nentries--;
sshkey_free(key);
success = 1;
done:
send_status(e, success);
}
static void
process_remove_all_identities(SocketEntry *e)
{
Identity *id;
/* Loop over all identities and clear the keys. */
for (id = TAILQ_FIRST(&idtab->idlist); id;
id = TAILQ_FIRST(&idtab->idlist)) {
TAILQ_REMOVE(&idtab->idlist, id, next);
free_identity(id);
}
/* Mark that there are no identities. */
idtab->nentries = 0;
/* Send success. */
send_status(e, 1);
}
/* removes expired keys and returns number of seconds until the next expiry */
static time_t
reaper(void)
{
time_t deadline = 0, now = monotime();
Identity *id, *nxt;
for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
nxt = TAILQ_NEXT(id, next);
if (id->death == 0)
continue;
if (now >= id->death) {
debug("expiring key '%s'", id->comment);
TAILQ_REMOVE(&idtab->idlist, id, next);
free_identity(id);
idtab->nentries--;
} else
deadline = (deadline == 0) ? id->death :
MINIMUM(deadline, id->death);
}
if (deadline == 0 || deadline <= now)
return 0;
else
return (deadline - now);
}
static void
process_add_identity(SocketEntry *e)
{
Identity *id;
int success = 0, confirm = 0;
u_int seconds, maxsign;
char *comment = NULL;
time_t death = 0;
struct sshkey *k = NULL;
u_char ctype;
int r = SSH_ERR_INTERNAL_ERROR;
if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
k == NULL ||
(r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
error("%s: decode private key: %s", __func__, ssh_err(r));
goto err;
}
while (sshbuf_len(e->request)) {
if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
error("%s: buffer error: %s", __func__, ssh_err(r));
goto err;
}
switch (ctype) {
case SSH_AGENT_CONSTRAIN_LIFETIME:
if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
error("%s: bad lifetime constraint: %s",
__func__, ssh_err(r));
goto err;
}
death = monotime() + seconds;
break;
case SSH_AGENT_CONSTRAIN_CONFIRM:
confirm = 1;
break;
case SSH_AGENT_CONSTRAIN_MAXSIGN:
if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
error("%s: bad maxsign constraint: %s",
__func__, ssh_err(r));
goto err;
}
if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
error("%s: cannot enable maxsign: %s",
__func__, ssh_err(r));
goto err;
}
break;
default:
error("%s: Unknown constraint %d", __func__, ctype);
err:
sshbuf_reset(e->request);
free(comment);
sshkey_free(k);
goto send;
}
}
success = 1;
if (lifetime && !death)
death = monotime() + lifetime;
if ((id = lookup_identity(k)) == NULL) {
id = xcalloc(1, sizeof(Identity));
TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
/* Increment the number of identities. */
idtab->nentries++;
} else {
/* key state might have been updated */
sshkey_free(id->key);
free(id->comment);
}
id->key = k;
id->comment = comment;
id->death = death;
id->confirm = confirm;
send:
send_status(e, success);
}
/* XXX todo: encrypt sensitive data with passphrase */
static void
process_lock_agent(SocketEntry *e, int lock)
{
int r, success = 0, delay;
char *passwd;
u_char passwdhash[LOCK_SIZE];
static u_int fail_count = 0;
size_t pwlen;
/*
* This is deliberately fatal: the user has requested that we lock,
* but we can't parse their request properly. The only safe thing to
* do is abort.
*/
if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (pwlen == 0) {
debug("empty password not supported");
} else if (locked && !lock) {
if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
fatal("bcrypt_pbkdf");
if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
debug("agent unlocked");
locked = 0;
fail_count = 0;
explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
success = 1;
} else {
/* delay in 0.1s increments up to 10s */
if (fail_count < 100)
fail_count++;
delay = 100000 * fail_count;
debug("unlock failed, delaying %0.1lf seconds",
(double)delay/1000000);
usleep(delay);
}
explicit_bzero(passwdhash, sizeof(passwdhash));
} else if (!locked && lock) {
debug("agent locked");
locked = 1;
arc4random_buf(lock_salt, sizeof(lock_salt));
if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
fatal("bcrypt_pbkdf");
success = 1;
}
explicit_bzero(passwd, pwlen);
free(passwd);
send_status(e, success);
}
static void
no_identities(SocketEntry *e)
{
struct sshbuf *msg;
int r;
if ((msg = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
(r = sshbuf_put_u32(msg, 0)) != 0 ||
(r = sshbuf_put_stringb(e->output, msg)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
sshbuf_free(msg);
}
#ifdef ENABLE_PKCS11
static void
process_add_smartcard_key(SocketEntry *e)
{
char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
int r, i, count = 0, success = 0, confirm = 0;
u_int seconds;
time_t death = 0;
u_char type;
struct sshkey **keys = NULL, *k;
Identity *id;
if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
(r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
error("%s: buffer error: %s", __func__, ssh_err(r));
goto send;
}
while (sshbuf_len(e->request)) {
if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
error("%s: buffer error: %s", __func__, ssh_err(r));
goto send;
}
switch (type) {
case SSH_AGENT_CONSTRAIN_LIFETIME:
if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
error("%s: buffer error: %s",
__func__, ssh_err(r));
goto send;
}
death = monotime() + seconds;
break;
case SSH_AGENT_CONSTRAIN_CONFIRM:
confirm = 1;
break;
default:
error("%s: Unknown constraint type %d", __func__, type);
goto send;
}
}
if (realpath(provider, canonical_provider) == NULL) {
verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
provider, strerror(errno));
goto send;
}
if (match_pattern_list(canonical_provider, pkcs11_whitelist, 0) != 1) {
verbose("refusing PKCS#11 add of \"%.100s\": "
"provider not whitelisted", canonical_provider);
goto send;
}
debug("%s: add %.100s", __func__, canonical_provider);
if (lifetime && !death)
death = monotime() + lifetime;
count = pkcs11_add_provider(canonical_provider, pin, &keys);
for (i = 0; i < count; i++) {
k = keys[i];
if (lookup_identity(k) == NULL) {
id = xcalloc(1, sizeof(Identity));
id->key = k;
id->provider = xstrdup(canonical_provider);
id->comment = xstrdup(canonical_provider); /* XXX */
id->death = death;
id->confirm = confirm;
TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
idtab->nentries++;
success = 1;
} else {
sshkey_free(k);
}
keys[i] = NULL;
}
send:
free(pin);
free(provider);
free(keys);
send_status(e, success);
}
static void
process_remove_smartcard_key(SocketEntry *e)
{
char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
int r, success = 0;
Identity *id, *nxt;
if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
(r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
error("%s: buffer error: %s", __func__, ssh_err(r));
goto send;
}
free(pin);
if (realpath(provider, canonical_provider) == NULL) {
verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
provider, strerror(errno));
goto send;
}
debug("%s: remove %.100s", __func__, canonical_provider);
for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
nxt = TAILQ_NEXT(id, next);
/* Skip file--based keys */
if (id->provider == NULL)
continue;
if (!strcmp(canonical_provider, id->provider)) {
TAILQ_REMOVE(&idtab->idlist, id, next);
free_identity(id);
idtab->nentries--;
}
}
if (pkcs11_del_provider(canonical_provider) == 0)
success = 1;
else
error("%s: pkcs11_del_provider failed", __func__);
send:
free(provider);
send_status(e, success);
}
#endif /* ENABLE_PKCS11 */
/* dispatch incoming messages */
static int
process_message(u_int socknum)
{
u_int msg_len;
u_char type;
const u_char *cp;
int r;
SocketEntry *e;
if (socknum >= sockets_alloc) {
fatal("%s: socket number %u >= allocated %u",
__func__, socknum, sockets_alloc);
}
e = &sockets[socknum];
if (sshbuf_len(e->input) < 5)
return 0; /* Incomplete message header. */
cp = sshbuf_ptr(e->input);
msg_len = PEEK_U32(cp);
if (msg_len > AGENT_MAX_LEN) {
debug("%s: socket %u (fd=%d) message too long %u > %u",
__func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
return -1;
}
if (sshbuf_len(e->input) < msg_len + 4)
return 0; /* Incomplete message body. */
/* move the current input to e->request */
sshbuf_reset(e->request);
if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
(r = sshbuf_get_u8(e->request, &type)) != 0) {
if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
r == SSH_ERR_STRING_TOO_LARGE) {
debug("%s: buffer error: %s", __func__, ssh_err(r));
return -1;
}
fatal("%s: buffer error: %s", __func__, ssh_err(r));
}
debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
/* check wheter agent is locked */
if (locked && type != SSH_AGENTC_UNLOCK) {
sshbuf_reset(e->request);
switch (type) {
case SSH2_AGENTC_REQUEST_IDENTITIES:
/* send empty lists */
no_identities(e);
break;
default:
/* send a fail message for all other request types */
send_status(e, 0);
}
return 0;
}
switch (type) {
case SSH_AGENTC_LOCK:
case SSH_AGENTC_UNLOCK:
process_lock_agent(e, type == SSH_AGENTC_LOCK);
break;
case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
process_remove_all_identities(e); /* safe for !WITH_SSH1 */
break;
/* ssh2 */
case SSH2_AGENTC_SIGN_REQUEST:
process_sign_request2(e);
break;
case SSH2_AGENTC_REQUEST_IDENTITIES:
process_request_identities(e);
break;
case SSH2_AGENTC_ADD_IDENTITY:
case SSH2_AGENTC_ADD_ID_CONSTRAINED:
process_add_identity(e);
break;
case SSH2_AGENTC_REMOVE_IDENTITY:
process_remove_identity(e);
break;
case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
process_remove_all_identities(e);
break;
#ifdef ENABLE_PKCS11
case SSH_AGENTC_ADD_SMARTCARD_KEY:
case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
process_add_smartcard_key(e);
break;
case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
process_remove_smartcard_key(e);
break;
#endif /* ENABLE_PKCS11 */
default:
/* Unknown message. Respond with failure. */
error("Unknown message %d", type);
sshbuf_reset(e->request);
send_status(e, 0);
break;
}
return 0;
}
static void
new_socket(sock_type type, int fd)
{
u_int i, old_alloc, new_alloc;
set_nonblock(fd);
if (fd > max_fd)
max_fd = fd;
for (i = 0; i < sockets_alloc; i++)
if (sockets[i].type == AUTH_UNUSED) {
sockets[i].fd = fd;
if ((sockets[i].input = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((sockets[i].output = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((sockets[i].request = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
sockets[i].type = type;
return;
}
old_alloc = sockets_alloc;
new_alloc = sockets_alloc + 10;
sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
for (i = old_alloc; i < new_alloc; i++)
sockets[i].type = AUTH_UNUSED;
sockets_alloc = new_alloc;
sockets[old_alloc].fd = fd;
if ((sockets[old_alloc].input = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((sockets[old_alloc].output = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((sockets[old_alloc].request = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
sockets[old_alloc].type = type;
}
static int
handle_socket_read(u_int socknum)
{
struct sockaddr_un sunaddr;
socklen_t slen;
uid_t euid;
gid_t egid;
int fd;
slen = sizeof(sunaddr);
fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
if (fd < 0) {
error("accept from AUTH_SOCKET: %s", strerror(errno));
return -1;
}
if (getpeereid(fd, &euid, &egid) < 0) {
error("getpeereid %d failed: %s", fd, strerror(errno));
close(fd);
return -1;
}
if ((euid != 0) && (getuid() != euid)) {
error("uid mismatch: peer euid %u != uid %u",
(u_int) euid, (u_int) getuid());
close(fd);
return -1;
}
new_socket(AUTH_CONNECTION, fd);
return 0;
}
static int
handle_conn_read(u_int socknum)
{
char buf[1024];
ssize_t len;
int r;
if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
if (len == -1) {
if (errno == EAGAIN || errno == EINTR)
return 0;
error("%s: read error on socket %u (fd %d): %s",
__func__, socknum, sockets[socknum].fd,
strerror(errno));
}
return -1;
}
if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
explicit_bzero(buf, sizeof(buf));
process_message(socknum);
return 0;
}
static int
handle_conn_write(u_int socknum)
{
ssize_t len;
int r;
if (sshbuf_len(sockets[socknum].output) == 0)
return 0; /* shouldn't happen */
if ((len = write(sockets[socknum].fd,
sshbuf_ptr(sockets[socknum].output),
sshbuf_len(sockets[socknum].output))) <= 0) {
if (len == -1) {
if (errno == EAGAIN || errno == EINTR)
return 0;
error("%s: read error on socket %u (fd %d): %s",
__func__, socknum, sockets[socknum].fd,
strerror(errno));
}
return -1;
}
if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
return 0;
}
static void
after_poll(struct pollfd *pfd, size_t npfd)
{
size_t i;
u_int socknum;
for (i = 0; i < npfd; i++) {
if (pfd[i].revents == 0)
continue;
/* Find sockets entry */
for (socknum = 0; socknum < sockets_alloc; socknum++) {
if (sockets[socknum].type != AUTH_SOCKET &&
sockets[socknum].type != AUTH_CONNECTION)
continue;
if (pfd[i].fd == sockets[socknum].fd)
break;
}
if (socknum >= sockets_alloc) {
error("%s: no socket for fd %d", __func__, pfd[i].fd);
continue;
}
/* Process events */
switch (sockets[socknum].type) {
case AUTH_SOCKET:
if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
handle_socket_read(socknum) != 0)
close_socket(&sockets[socknum]);
break;
case AUTH_CONNECTION:
if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
handle_conn_read(socknum) != 0) {
close_socket(&sockets[socknum]);
break;
}
if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
handle_conn_write(socknum) != 0)
close_socket(&sockets[socknum]);
break;
default:
break;
}
}
}
static int
prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp)
{
struct pollfd *pfd = *pfdp;
size_t i, j, npfd = 0;
time_t deadline;
/* Count active sockets */
for (i = 0; i < sockets_alloc; i++) {
switch (sockets[i].type) {
case AUTH_SOCKET:
case AUTH_CONNECTION:
npfd++;
break;
case AUTH_UNUSED:
break;
default:
fatal("Unknown socket type %d", sockets[i].type);
break;
}
}
if (npfd != *npfdp &&
(pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
fatal("%s: recallocarray failed", __func__);
*pfdp = pfd;
*npfdp = npfd;
for (i = j = 0; i < sockets_alloc; i++) {
switch (sockets[i].type) {
case AUTH_SOCKET:
case AUTH_CONNECTION:
pfd[j].fd = sockets[i].fd;
pfd[j].revents = 0;
/* XXX backoff when input buffer full */
pfd[j].events = POLLIN;
if (sshbuf_len(sockets[i].output) > 0)
pfd[j].events |= POLLOUT;
j++;
break;
default:
break;
}
}
deadline = reaper();
if (parent_alive_interval != 0)
deadline = (deadline == 0) ? parent_alive_interval :
MINIMUM(deadline, parent_alive_interval);
if (deadline == 0) {
*timeoutp = -1; /* INFTIM */
} else {
if (deadline > INT_MAX / 1000)
*timeoutp = INT_MAX / 1000;
else
*timeoutp = deadline * 1000;
}
return (1);
}
static void
cleanup_socket(void)
{
if (cleanup_pid != 0 && getpid() != cleanup_pid)
return;
debug("%s: cleanup", __func__);
if (socket_name[0])
unlink(socket_name);
if (socket_dir[0])
rmdir(socket_dir);
}