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pivy-agent.c
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pivy-agent.c
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/*
* Newly written portions Copyright 2018 Joyent, Inc.
* Copyright 2023 The University of Queensland
* Author: Alex Wilson <[email protected]>, <[email protected]>
*
* 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.
*/
/*
* Partially derived from the original OpenSSH agent.c.
*
* Original copyright and license from OpenSSH:
*
* Author: Tatu Ylonen <[email protected]>
* Copyright (c) 1995 Tatu Ylonen <[email protected]>, 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 <sys/types.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/un.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include "debug.h"
#include <openssl/err.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/evp.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <paths.h>
#include <poll.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <unistd.h>
#include <libgen.h>
#include <pwd.h>
#include "utils.h"
#include "openssh/config.h"
#include "openssh/ssh2.h"
#include "openssh/sshbuf.h"
#include "openssh/sshkey.h"
#include "openssh/authfd.h"
#include "openssh/ssherr.h"
#include "bunyan.h"
#include "tlv.h"
#include "piv.h"
#include "errf.h"
#include "slot-spec.h"
#if defined(__APPLE__)
#include <PCSC/wintypes.h>
#include <PCSC/winscard.h>
#else
#include <wintypes.h>
#include <winscard.h>
#endif
#if defined(__sun)
#include <ucred.h>
#include <procfs.h>
#include <zone.h>
#endif
#if defined(__OpenBSD__)
#include <sys/sysctl.h>
#endif
#if defined(__APPLE__)
#include <sys/proc_info.h>
#include <sys/ucred.h>
#include <libproc.h>
#endif
#include "openssh/digest.h"
#include "openssh/cipher.h"
#include "openssh/ssherr.h"
#define MINIMUM(a,b) (((a) < (b)) ? (a) : (b))
/*
* Name of the environment variable containing the process ID of the
* authentication agent.
*/
#define SSH_AGENTPID_ENV_NAME "SSH_AGENT_PID"
/*
* Name of the environment variable containing the pathname of the
* authentication socket.
*/
#define SSH_AUTHSOCKET_ENV_NAME "SSH_AUTH_SOCK"
/* Listen backlog for sshd, ssh-agent and forwarding sockets */
#define SSH_LISTEN_BACKLOG 128
#define MAX_PIN_LEN 16
#define parserrf(sshfunc, rc) \
errf("ParseError", ssherrf(sshfunc, rc), \
"failed to parse request in %s", __func__)
#define nopinerrf(cause) \
errf("NoPINError", cause, "no PIN has been supplied to the agent " \
"(try ssh-add -X)")
#define flagserrf(val) \
errf("FlagsError", NULL, "unsupported flags value: %x", val)
#define pcscerrf(call, rv) \
errf("PCSCError", NULL, call " failed: %d (%s)", \
rv, pcsc_stringify_error(rv))
typedef enum confirm_mode {
C_NEVER,
C_CONNECTION,
C_FORWARDED
} confirm_mode_t;
static struct piv_token *ks = NULL;
static struct piv_token *selk = NULL;
static boolean_t txnopen = B_FALSE;
static uint64_t txntimeout = 0;
static struct piv_ctx *ctx;
static uint64_t last_update;
static uint8_t *guid = NULL;
static size_t guid_len = 0;
static boolean_t sign_9d = B_FALSE;
static confirm_mode_t confirm_mode = C_NEVER;
static struct slotspec *slot_ena;
typedef struct uid_entry {
struct uid_entry *ue_next;
uid_t ue_uid;
} uid_entry_t;
#define UID_MOD 32
static uid_entry_t *uid_allow[UID_MOD] = { NULL };
static boolean_t allow_any_uid = B_FALSE;
#if defined(__sun)
typedef struct zone_entry {
struct zone_entry *ze_next;
zoneid_t ze_zid;
} zone_entry_t;
#define ZID_MOD 32
static zone_entry_t *zone_allow[ZID_MOD] = { NULL };
static boolean_t allow_any_zoneid = B_FALSE;
#endif
static char *pinmem = NULL;
static char *pin = NULL;
static size_t pin_len = 0;
static struct sshkey *cak = NULL;
static struct bunyan_frame *msg_log_frame;
/* Maximum accepted message length */
#define AGENT_MAX_LEN (256*1024)
typedef enum sock_type {
AUTH_UNUSED,
AUTH_SOCKET,
AUTH_CONNECTION
} sock_type_t;
typedef enum authz {
AUTHZ_NOT_YET = 0,
AUTHZ_DENIED,
AUTHZ_ALLOWED
} authz_t;
typedef enum sessbind {
SESSBIND_NONE = 0,
SESSBIND_AUTH,
SESSBIND_FWD
} sessbind_t;
typedef struct pid_entry {
boolean_t pe_valid;
uint64_t pe_time;
pid_t pe_pid;
uint64_t pe_start_time;
uint pe_conn_count;
uint64_t pe_last_auth;
} pid_entry_t;
typedef struct socket_entry {
int se_fd;
sock_type_t se_type;
pid_t se_pid;
uid_t se_uid;
gid_t se_gid;
char *se_exepath;
char *se_exeargs;
authz_t se_authz;
struct sshbuf *se_input;
struct sshbuf *se_output;
struct sshbuf *se_request;
pid_entry_t *se_pid_ent;
uint se_pid_idx;
sessbind_t se_sbind;
#if defined(__sun)
zoneid_t se_zid;
char se_zname[128];
#endif
} socket_entry_t;
u_int sockets_alloc = 0;
socket_entry_t *sockets = NULL;
pid_entry_t *pids = NULL;
uint pids_alloc = 0;
int max_fd = 0;
const time_t card_probe_interval_nopin = 120;
const time_t card_probe_interval_pin = 30;
const uint card_probe_limit = 3;
const uint64_t pid_auth_cache_time = 15000;
time_t card_probe_interval = 120; /* card_probe_interval_nopin */
uint card_probe_fails = 0;
uint64_t card_probe_next = 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 + 20];
char socket_dir[PATH_MAX];
/* 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;
extern void bunyan_timestamp(char *, size_t);
static int ssh_dbglevel = BNY_WARN;
static void
sdebug(const char *fmt, ...)
{
va_list args;
char ts[128];
if (ssh_dbglevel > BNY_TRACE)
return;
bunyan_timestamp(ts, sizeof (ts));
va_start(args, fmt);
fprintf(stderr, "[%s] TRACE: ", ts);
vfprintf(stderr, fmt, args);
fprintf(stderr, "\n");
va_end(args);
}
static void
error(const char *fmt, ...)
{
va_list args;
char ts[128];
if (ssh_dbglevel > BNY_ERROR)
return;
bunyan_timestamp(ts, sizeof (ts));
va_start(args, fmt);
fprintf(stderr, "[%s] ERROR: ", ts);
vfprintf(stderr, fmt, args);
fprintf(stderr, "\n");
va_end(args);
}
static void
fatal(const char *fmt, ...)
{
va_list args;
char ts[128];
va_start(args, fmt);
bunyan_timestamp(ts, sizeof (ts));
fprintf(stderr, "[%s] FATAL: ", ts);
vfprintf(stderr, fmt, args);
fprintf(stderr, "\n");
va_end(args);
exit(1);
}
static uint64_t
monotime(void)
{
struct timeval tv;
uint64_t msec;
gettimeofday(&tv, NULL);
msec = tv.tv_sec * 1000;
msec += tv.tv_usec / 1000;
return (msec);
}
static inline boolean_t
is_slot_enabled(struct piv_slot *slot)
{
return (slotspec_test(slot_ena, piv_slot_id(slot)));
}
static void
add_uid(uid_t uid)
{
uid_entry_t *ue;
uint slot = uid % UID_MOD;
ue = calloc(1, sizeof (uid_entry_t));
ue->ue_uid = uid;
ue->ue_next = uid_allow[slot];
uid_allow[slot] = ue;
}
static int
check_uid(uid_t uid)
{
uid_entry_t *ue;
uint slot = uid % UID_MOD;
for (ue = uid_allow[slot]; ue != NULL; ue = ue->ue_next) {
if (ue->ue_uid == uid)
return (1);
}
return (0);
}
#if defined(__sun)
static void
add_zid(zoneid_t zid)
{
zone_entry_t *ze;
uint slot = zid % ZID_MOD;
ze = calloc(1, sizeof (zone_entry_t));
ze->ze_zid = zid;
ze->ze_next = zone_allow[slot];
zone_allow[slot] = ze;
}
static int
check_zid(zoneid_t zid)
{
zone_entry_t *ze;
uint slot = zid % ZID_MOD;
for (ze = zone_allow[slot]; ze != NULL; ze = ze->ze_next) {
if (ze->ze_zid == zid)
return (1);
}
return (0);
}
#endif
static void
agent_piv_close(boolean_t force)
{
uint64_t now = monotime();
VERIFY(txnopen);
if (force || now >= txntimeout) {
bunyan_log(BNY_TRACE, "closing txn",
"now", BNY_UINT64, now,
"txntimeout", BNY_UINT64, txntimeout, NULL);
piv_txn_end(selk);
txnopen = B_FALSE;
}
}
static char *
piv_token_shortid(struct piv_token *pk)
{
char *guid;
if (piv_token_has_chuid(pk)) {
guid = strdup(piv_token_guid_hex(pk));
} else {
guid = strdup("0000000000");
}
guid[8] = '\0';
return (guid);
}
static const char *
pin_type_to_name(enum piv_pin type)
{
switch (type) {
case PIV_PIN:
return ("PIV PIN");
case PIV_GLOBAL_PIN:
return ("Global PIN");
case PIV_PUK:
return ("PUK");
default:
VERIFY(0);
return (NULL);
}
}
static errf_t *
valid_pin(const char *pin)
{
int i;
if (strlen(pin) < 4 || strlen(pin) > 8) {
return (errf("InvalidPIN", NULL, "PIN must be 4-8 characters "
"(was given %d)", strlen(pin)));
}
for (i = 0; pin[i] != 0; ++i) {
if (!(pin[i] >= '0' && pin[i] <= '9') &&
!(pin[i] >= 'a' && pin[i] <= 'z') &&
!(pin[i] >= 'A' && pin[i] <= 'Z')) {
return (errf("InvalidPIN", NULL, "PIN contains "
"invalid characters: '%c'", pin[i]));
}
}
return (NULL);
}
static void
set_probe_interval(boolean_t pin_loaded)
{
uint64_t now;
now = monotime();
if (pin_loaded)
card_probe_interval = card_probe_interval_pin;
else
card_probe_interval = card_probe_interval_nopin;
now += card_probe_interval * 1000;
if (now <= card_probe_next)
card_probe_next = now;
}
static void
extend_probe_deadline(void)
{
uint64_t now;
now = monotime();
now += card_probe_interval * 1000;
card_probe_next = now;
}
static void
drop_pin(void)
{
if (pin_len != 0) {
bunyan_log(BNY_INFO, "clearing PIN from memory", NULL);
explicit_bzero(pin, pin_len);
}
pin_len = 0;
set_probe_interval(B_FALSE);
}
static errf_t *
auth_cak(void)
{
struct piv_slot *slot;
errf_t *err;
slot = piv_get_slot(selk, PIV_SLOT_CARD_AUTH);
if (slot == NULL) {
err = errf("CAKAuthError", NULL, "No key was found in the "
"CARD_AUTH (CAK) slot");
return (err);
}
err = piv_auth_key(selk, slot, cak);
if (err) {
err = errf("CAKAuthError", err, "Key in CARD_AUTH slot (CAK) "
"does not match the configured CAK: this card may be "
"a fake!");
return (err);
}
return (NULL);
}
static errf_t *
agent_piv_open(void)
{
struct piv_slot *slot;
errf_t *err = NULL;
if (txnopen) {
txntimeout = monotime() + 2000;
return (NULL);
}
if (selk == NULL || (err = piv_txn_begin(selk))) {
errf_free(err);
selk = NULL;
if (ks != NULL)
piv_release(ks);
findagain:
err = piv_find(ctx, guid, guid_len, &ks);
if (err && errf_caused_by(err, "PCSCContextError")) {
ks = NULL;
bunyan_log(BNY_TRACE, "got context error, re-initing",
"error", BNY_ERF, err, NULL);
errf_free(err);
piv_close(ctx);
ctx = piv_open();
err = piv_establish_context(ctx, SCARD_SCOPE_SYSTEM);
if (err)
return (err);
goto findagain;
} else if (err) {
ks = NULL;
err = errf("EnumerationError", err, "Failed to "
"find specified PIV token on the system");
return (err);
}
selk = ks;
if (selk == NULL) {
err = errf("NotFoundError", NULL, "PIV card with "
"given GUID is not present on the system");
if (monotime() - last_update > 5000)
drop_pin();
return (err);
}
if ((err = piv_txn_begin(selk))) {
return (err);
}
if ((err = piv_select(selk))) {
piv_txn_end(selk);
return (err);
}
err = piv_read_all_certs(selk);
if (err && !errf_caused_by(err, "NotFoundError") &&
!errf_caused_by(err, "NotSupportedError")) {
piv_txn_end(selk);
return (err);
}
if (cak != NULL && (err = auth_cak())) {
piv_txn_end(selk);
drop_pin();
return (err);
}
last_update = monotime();
} else {
if ((err = piv_select(selk))) {
piv_txn_end(selk);
return (err);
}
}
if (cak == NULL) {
slot = piv_get_slot(selk, PIV_SLOT_CARD_AUTH);
if (slot != NULL)
VERIFY0(sshkey_demote(piv_slot_pubkey(slot), &cak));
}
bunyan_log(BNY_TRACE, "opened new txn", NULL);
txnopen = B_TRUE;
txntimeout = monotime() + 2000;
card_probe_fails = 0;
return (NULL);
}
static void
probe_card(void)
{
errf_t *err;
uint64_t now;
now = monotime();
card_probe_next = now + card_probe_interval * 1000;
if (card_probe_fails > card_probe_limit)
return;
bunyan_log(BNY_TRACE, "doing idle probe", NULL);
if ((err = agent_piv_open())) {
bunyan_log(BNY_TRACE, "error opening for idle probe",
"error", BNY_ERF, err, NULL);
errf_free(err);
/*
* Allow one failure due to connectivity issues before we
* drop the PIN (so that transient glitches aren't so
* inconvenient).
*/
if (card_probe_fails++ > 0)
drop_pin();
selk = NULL;
card_probe_next = now + card_probe_interval * 1000;
return;
}
if (cak != NULL && (err = auth_cak())) {
bunyan_log(BNY_WARN, "CAK authentication failed",
"error", BNY_ERF, err, NULL);
agent_piv_close(B_TRUE);
/* Always drop PIN on a CAK failure. */
drop_pin();
selk = NULL;
card_probe_fails++;
card_probe_next = now + card_probe_interval * 1000;
return;
}
agent_piv_close(B_FALSE);
card_probe_fails = 0;
}
static errf_t *
wrap_pin_error(errf_t *err, int retries)
{
if (errf_caused_by(err, "PermissionError")) {
if (retries == 0) {
err = errf("TokenLocked", err,
"PIV token is locked due to too many "
"invalid PIN code attempts");
} else {
err = errf("InvalidPIN", err,
"Invalid PIN code supplied (%d attempts "
"remaining)", retries);
drop_pin();
}
} else if (errf_caused_by(err, "MinRetriesError")) {
err = errf("TokenLocked", err,
"Refusing to use up the last PIN code attempt: "
"unlock the token with another tool to clear "
"the counter (e.g. pivy-tool with -f)");
drop_pin();
}
return (err);
}
static const char *askpass = NULL;
static const char *confirm = NULL;
static const char *notify = NULL;
static void
try_askpass(void)
{
int p[2], status;
pid_t kid, ret;
size_t len;
errf_t *err;
uint retries = 1;
char prompt[64], buf[1024];
char *guid = piv_token_shortid(selk);
enum piv_pin auth = piv_token_default_auth(selk);
snprintf(prompt, 64, "Enter %s for token %s",
pin_type_to_name(auth), guid);
if (askpass == NULL)
askpass = getenv("SSH_ASKPASS");
if (askpass == NULL)
return;
if (pipe(p) == -1)
return;
if ((kid = fork()) == -1)
return;
if (kid == 0) {
close(p[0]);
if (dup2(p[1], STDOUT_FILENO) == -1)
exit(1);
execlp(askpass, askpass, prompt, (char *)NULL);
exit(1);
}
close(p[1]);
len = 0;
do {
ssize_t r = read(p[0], buf + len, sizeof(buf) - 1 - len);
if (r == -1 && errno == EINTR)
continue;
if (r <= 0)
break;
len += r;
} while (sizeof(buf) - 1 - len > 0);
buf[len] = '\0';
close(p[0]);
while ((ret = waitpid(kid, &status, 0)) == -1)
if (errno != EINTR)
break;
if (ret == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
explicit_bzero(buf, sizeof(buf));
bunyan_log(BNY_WARN, "executing askpass failed",
"exit_status", BNY_UINT, (uint)WEXITSTATUS(status),
NULL);
return;
}
buf[strcspn(buf, "\r\n")] = '\0';
if ((err = valid_pin(buf))) {
errf_free(err);
goto out;
}
if ((err = agent_piv_open())) {
errf_free(err);
goto out;
}
err = piv_verify_pin(selk, auth, buf, &retries, B_FALSE);
if (err != ERRF_OK) {
err = wrap_pin_error(err, retries);
bunyan_log(BNY_WARN, "failed to use PIN provided by askpass",
"error", BNY_ERF, err, NULL);
errf_free(err);
goto out;
}
extend_probe_deadline();
agent_piv_close(B_FALSE);
if (pin_len != 0)
explicit_bzero(pin, pin_len);
pin_len = strlen(buf);
bcopy(buf, pin, pin_len);
bunyan_log(BNY_INFO, "storing PIN in memory", NULL);
set_probe_interval(B_TRUE);
out:
explicit_bzero(buf, sizeof(buf));
}
static void
send_touch_notify(socket_entry_t *e, enum piv_slotid slotid)
{
int status;
pid_t kid, ret;
char msg[1024];
char title[256];
char *guid;
if (notify == NULL)
notify = getenv("SSH_NOTIFY_SEND");
if (notify == NULL)
return;
guid = piv_token_shortid(selk);
snprintf(title, sizeof (title),
"pivy-agent for token %s", guid);
snprintf(msg, sizeof (msg),
"Touch confirmation may be required to use key in slot %02X",
slotid);
free(guid);
guid = NULL;
if ((kid = fork()) == -1)
return;
if (kid == 0) {
close(STDOUT_FILENO);
close(STDIN_FILENO);
execlp(notify, notify, title, msg, (char *)NULL);
exit(128);
}
while ((ret = waitpid(kid, &status, 0)) == -1)
if (errno != EINTR)
break;
if (ret == -1 || !WIFEXITED(status) ||
(WEXITSTATUS(status) != 0 && WEXITSTATUS(status) != 1)) {
bunyan_log(BNY_WARN, "executing notify failed",
"exit_status", BNY_UINT, (uint)WEXITSTATUS(status),
NULL);
return;
}
}
static void
try_confirm_client(socket_entry_t *e, enum piv_slotid slotid)
{
int status;
pid_t kid, ret;
boolean_t add_zenity_args = B_FALSE;
boolean_t add_notify_send_args = B_FALSE;
char prompt[1024], buf[64];
size_t len;
char *guid;
int p[2];
if (confirm_mode == C_NEVER) {
e->se_authz = AUTHZ_ALLOWED;
return;
}
if (confirm_mode == C_FORWARDED) {
const char *ssh = NULL;
const size_t len = strlen(e->se_exepath);
const uint64_t now = monotime();
const int64_t delta = now - e->se_pid_ent->pe_last_auth;
/*
* If we've seen a session-bind for auth, this isn't a
* forwarded connection.
*/
if (e->se_sbind == SESSBIND_AUTH) {
e->se_authz = AUTHZ_ALLOWED;
return;
}
/*
* If we haven't seen a session-bind at all, sniff whether this
* is an "ssh" process connected to us. If this is the very
* first connection that "ssh" process has made, assume it's
* the auth socket.
*/
if (e->se_sbind == SESSBIND_NONE) {
if (len >= 4)
ssh = &e->se_exepath[len - 4];
if (ssh != NULL && strcmp(ssh, "/ssh") != 0)
ssh = NULL;
if (len == 3 && strcmp(e->se_exepath, "ssh") == 0)
ssh = e->se_exepath;
if (e->se_pid_idx == 0 || ssh == NULL) {
e->se_authz = AUTHZ_ALLOWED;
return;
}
}
/*
* Otherwise, check if the user has authorised this PID
* recently -- if they have, this connection is ok (and we
* should renew the PID's authorisation).
*/
if (e->se_pid_ent->pe_pid != 0 &&
pid_auth_cache_time > 0 &&
delta < pid_auth_cache_time) {
e->se_pid_ent->pe_last_auth = now;
e->se_authz = AUTHZ_ALLOWED;
return;
}
}
/* Otherwise we're going to try to obtain user consent. */
if (askpass == NULL)
askpass = getenv("SSH_ASKPASS");
if (confirm == NULL)
confirm = getenv("SSH_CONFIRM");
if (askpass == NULL && confirm == NULL) {
e->se_authz = AUTHZ_DENIED;
return;
}
if (confirm != NULL) {
char *tmp = strdup(confirm);
const char *execname = basename(tmp);
if (strcmp(execname, "zenity") == 0)
add_zenity_args = B_TRUE;
if (strcmp(execname, "notify-send") == 0)
add_notify_send_args = B_TRUE;
free(tmp);
}
bunyan_log(BNY_INFO, "requesting user confirmation",
"exec", BNY_STRING, confirm,
"zenity", BNY_INT, add_zenity_args,
"notify-send", BNY_INT, add_notify_send_args,
NULL);
guid = piv_token_shortid(selk);
snprintf(prompt, sizeof (prompt),
"%sA new client is trying to use PIV token %s\r\n\r\n"
"Client PID: %d\r\nClient executable: %s\r\nClient cmd: %s\r\n"
"Slot requested: %02x",
(add_zenity_args ? "--text=" : ""),
guid, (int)e->se_pid,
(e->se_exepath == NULL) ? "(unknown)" : e->se_exepath,
(e->se_exeargs == NULL) ? "(unknown)" : e->se_exeargs,
(uint)slotid);
free(guid);
guid = NULL;
if (pipe(p) == -1)
return;
if ((kid = fork()) == -1)
return;
if (kid == 0) {
close(STDOUT_FILENO);
close(STDIN_FILENO);
close(p[0]);
if (dup2(p[1], STDOUT_FILENO) == -1)
exit(1);
if (confirm && add_zenity_args) {
execlp(confirm, confirm,
"--question", "--ok-label=Allow",
"--cancel-label=Block", "--width=300",
"--title=pivy-agent",
"--icon-name=application-certificate-symbolic",
prompt,
(char *)NULL);
} else if (confirm && add_notify_send_args) {
execlp(confirm, confirm,
"--app-name=pivy-agent",
"--icon=user-info",
"--urgency=critical",
"--expire-time=0",
"--wait",
"--action=allow=Allow",
"--action=deny=Deny",
"pivy-agent confirmation",
prompt,
(char *)NULL);
} else if (confirm) {
execlp(confirm, confirm, prompt, (char *)NULL);
} else {
setenv("SSH_ASKPASS_PROMPT", "confirm", 1);
execlp(askpass, askpass, prompt, (char *)NULL);
}
exit(128);
}
close(p[1]);
while ((ret = waitpid(kid, &status, 0)) == -1)
if (errno != EINTR)
break;
if (ret == -1 || !WIFEXITED(status) ||
(WEXITSTATUS(status) != 0 && WEXITSTATUS(status) != 1)) {
bunyan_log(BNY_WARN, "executing confirm failed",
"exit_status", BNY_UINT, (uint)WEXITSTATUS(status),
NULL);
return;
}
len = 0;
do {
ssize_t r = read(p[0], buf + len, sizeof(buf) - 1 - len);
if (r == -1 && errno == EINTR)
continue;
if (r <= 0)
break;
len += r;
} while (sizeof(buf) - 1 - len > 0);
buf[len] = '\0';
close(p[0]);
if (WEXITSTATUS(status) == 0 && (!add_notify_send_args ||
strcmp(buf, "allow\n") == 0)) {
e->se_authz = AUTHZ_ALLOWED;
e->se_pid_ent->pe_last_auth = monotime();
} else {