#include "includes.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif
#include <pwd.h>
#include <signal.h>
#ifdef HAVE_STDINT_H
# include <stdint.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <unistd.h>
#ifdef HAVE_POLL_H
#include <poll.h>
#else
# ifdef HAVE_SYS_POLL_H
# include <sys/poll.h>
# endif
#endif
#ifdef WITH_OPENSSL
#include <openssl/dh.h>
#endif
#include "openbsd-compat/sys-tree.h"
#include "openbsd-compat/sys-queue.h"
#include "openbsd-compat/openssl-compat.h"
#include "atomicio.h"
#include "xmalloc.h"
#include "ssh.h"
#include "sshkey.h"
#include "sshbuf.h"
#include "hostfile.h"
#include "auth.h"
#include "cipher.h"
#include "kex.h"
#include "dh.h"
#include "auth-pam.h"
#include "packet.h"
#include "auth-options.h"
#include "sshpty.h"
#include "channels.h"
#include "session.h"
#include "sshlogin.h"
#include "canohost.h"
#include "log.h"
#include "misc.h"
#include "servconf.h"
#include "monitor.h"
#include "blocklist_client.h"
#ifdef GSSAPI
#include "ssh-gss.h"
#endif
#include "monitor_wrap.h"
#include "monitor_fdpass.h"
#include "compat.h"
#include "ssh2.h"
#include "authfd.h"
#include "match.h"
#include "ssherr.h"
#include "sk-api.h"
#include "srclimit.h"
#ifdef GSSAPI
static Gssctxt *gsscontext = NULL;
#endif
extern ServerOptions options;
extern u_int utmp_len;
extern struct sshbuf *cfg;
extern struct sshbuf *loginmsg;
extern struct include_list includes;
extern struct sshauthopt *auth_opts;
static struct sshbuf *child_state;
int mm_answer_moduli(struct ssh *, int, struct sshbuf *);
int mm_answer_sign(struct ssh *, int, struct sshbuf *);
int mm_answer_pwnamallow(struct ssh *, int, struct sshbuf *);
int mm_answer_auth2_read_banner(struct ssh *, int, struct sshbuf *);
int mm_answer_authserv(struct ssh *, int, struct sshbuf *);
int mm_answer_authpassword(struct ssh *, int, struct sshbuf *);
int mm_answer_bsdauthquery(struct ssh *, int, struct sshbuf *);
int mm_answer_bsdauthrespond(struct ssh *, int, struct sshbuf *);
int mm_answer_keyallowed(struct ssh *, int, struct sshbuf *);
int mm_answer_keyverify(struct ssh *, int, struct sshbuf *);
int mm_answer_pty(struct ssh *, int, struct sshbuf *);
int mm_answer_pty_cleanup(struct ssh *, int, struct sshbuf *);
int mm_answer_term(struct ssh *, int, struct sshbuf *);
int mm_answer_state(struct ssh *, int, struct sshbuf *);
#ifdef USE_PAM
int mm_answer_pam_start(struct ssh *, int, struct sshbuf *);
int mm_answer_pam_account(struct ssh *, int, struct sshbuf *);
int mm_answer_pam_init_ctx(struct ssh *, int, struct sshbuf *);
int mm_answer_pam_query(struct ssh *, int, struct sshbuf *);
int mm_answer_pam_respond(struct ssh *, int, struct sshbuf *);
int mm_answer_pam_free_ctx(struct ssh *, int, struct sshbuf *);
#endif
#ifdef GSSAPI
int mm_answer_gss_setup_ctx(struct ssh *, int, struct sshbuf *);
int mm_answer_gss_accept_ctx(struct ssh *, int, struct sshbuf *);
int mm_answer_gss_userok(struct ssh *, int, struct sshbuf *);
int mm_answer_gss_checkmic(struct ssh *, int, struct sshbuf *);
#endif
#ifdef SSH_AUDIT_EVENTS
int mm_answer_audit_event(struct ssh *, int, struct sshbuf *);
int mm_answer_audit_command(struct ssh *, int, struct sshbuf *);
#endif
static Authctxt *authctxt;
static u_char *key_blob = NULL;
static size_t key_bloblen = 0;
static u_int key_blobtype = MM_NOKEY;
static struct sshauthopt *key_opts = NULL;
static char *hostbased_cuser = NULL;
static char *hostbased_chost = NULL;
static char *auth_method = "unknown";
static char *auth_submethod = NULL;
static u_int session_id2_len = 0;
static u_char *session_id2 = NULL;
static pid_t monitor_child_pid;
int auth_attempted = 0;
struct mon_table {
enum monitor_reqtype type;
int flags;
int (*f)(struct ssh *, int, struct sshbuf *);
};
#define MON_ISAUTH 0x0004
#define MON_AUTHDECIDE 0x0008
#define MON_ONCE 0x0010
#define MON_ALOG 0x0020
#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
#define MON_PERMIT 0x1000
static int monitor_read(struct ssh *, struct monitor *, struct mon_table *,
struct mon_table **);
static int monitor_read_log(struct monitor *);
struct mon_table mon_dispatch_proto20[] = {
{MONITOR_REQ_STATE, MON_ONCE, mm_answer_state},
#ifdef WITH_OPENSSL
{MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
#endif
{MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
{MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
{MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
{MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
{MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
#ifdef USE_PAM
{MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
{MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
{MONITOR_REQ_PAM_INIT_CTX, MON_ONCE, mm_answer_pam_init_ctx},
{MONITOR_REQ_PAM_QUERY, 0, mm_answer_pam_query},
{MONITOR_REQ_PAM_RESPOND, MON_ONCE, mm_answer_pam_respond},
{MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
#endif
#ifdef SSH_AUDIT_EVENTS
{MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
#endif
#ifdef BSD_AUTH
{MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
{MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
#endif
{MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
{MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
#ifdef GSSAPI
{MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
{MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
{MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok},
{MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic},
#endif
{0, 0, NULL}
};
struct mon_table mon_dispatch_postauth20[] = {
{MONITOR_REQ_STATE, MON_ONCE, mm_answer_state},
#ifdef WITH_OPENSSL
{MONITOR_REQ_MODULI, 0, mm_answer_moduli},
#endif
{MONITOR_REQ_SIGN, 0, mm_answer_sign},
{MONITOR_REQ_PTY, 0, mm_answer_pty},
{MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
{MONITOR_REQ_TERM, 0, mm_answer_term},
#ifdef SSH_AUDIT_EVENTS
{MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
{MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
#endif
{0, 0, NULL}
};
struct mon_table *mon_dispatch;
static void
monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
{
while (ent->f != NULL) {
if (ent->type == type) {
ent->flags &= ~MON_PERMIT;
ent->flags |= permit ? MON_PERMIT : 0;
return;
}
ent++;
}
}
static void
monitor_permit_authentications(int permit)
{
struct mon_table *ent = mon_dispatch;
while (ent->f != NULL) {
if (ent->flags & MON_AUTH) {
ent->flags &= ~MON_PERMIT;
ent->flags |= permit ? MON_PERMIT : 0;
}
ent++;
}
}
void
monitor_child_preauth(struct ssh *ssh, struct monitor *pmonitor)
{
struct mon_table *ent;
int authenticated = 0, partial = 0;
debug3("preauth child monitor started");
if (pmonitor->m_recvfd >= 0)
close(pmonitor->m_recvfd);
if (pmonitor->m_log_sendfd >= 0)
close(pmonitor->m_log_sendfd);
pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
authctxt = (Authctxt *)ssh->authctxt;
memset(authctxt, 0, sizeof(*authctxt));
ssh->authctxt = authctxt;
authctxt->loginmsg = loginmsg;
mon_dispatch = mon_dispatch_proto20;
monitor_permit(mon_dispatch, MONITOR_REQ_STATE, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
while (!authenticated) {
partial = 0;
auth_method = "unknown";
auth_submethod = NULL;
auth2_authctxt_reset_info(authctxt);
authenticated = (monitor_read(ssh, pmonitor,
mon_dispatch, &ent) == 1);
if ((ent->flags & MON_AUTH) != 0)
auth_attempted = 1;
if (options.num_auth_methods != 0) {
if (authenticated &&
!auth2_update_methods_lists(authctxt,
auth_method, auth_submethod)) {
debug3_f("method %s: partial", auth_method);
authenticated = 0;
partial = 1;
}
}
if (authenticated) {
if (!(ent->flags & MON_AUTHDECIDE))
fatal_f("unexpected authentication from %d",
ent->type);
if (authctxt->pw->pw_uid == 0 &&
!auth_root_allowed(ssh, auth_method))
authenticated = 0;
#ifdef USE_PAM
if (options.use_pam && authenticated) {
struct sshbuf *m;
if ((m = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed",
__func__);
mm_request_receive_expect(pmonitor->m_sendfd,
MONITOR_REQ_PAM_ACCOUNT, m);
authenticated = mm_answer_pam_account(
ssh, pmonitor->m_sendfd, m);
sshbuf_free(m);
}
#endif
}
if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
auth_log(ssh, authenticated, partial,
auth_method, auth_submethod);
if (!partial && !authenticated)
authctxt->failures++;
if (authenticated || partial) {
auth2_update_session_info(authctxt,
auth_method, auth_submethod);
}
}
if (authctxt->failures > options.max_authtries) {
BLOCKLIST_NOTIFY(ssh, BLOCKLIST_AUTH_FAIL,
"Too many authentication attempts");
fatal_f("privsep child made too many authentication "
"attempts");
}
}
if (!authctxt->valid) {
BLOCKLIST_NOTIFY(ssh, BLOCKLIST_AUTH_FAIL,
"Authenticated invalid user");
fatal_f("authenticated invalid user");
}
if (strcmp(auth_method, "unknown") == 0) {
BLOCKLIST_NOTIFY(ssh, BLOCKLIST_AUTH_FAIL,
"Authentication method name unknown");
fatal_f("authentication method name unknown");
}
debug_f("user %s authenticated by privileged process", authctxt->user);
auth_attempted = 0;
ssh->authctxt = NULL;
ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
mm_get_keystate(ssh, pmonitor);
while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
;
if (pmonitor->m_recvfd >= 0)
close(pmonitor->m_recvfd);
if (pmonitor->m_log_sendfd >= 0)
close(pmonitor->m_log_sendfd);
pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
}
static void
monitor_set_child_handler(pid_t pid)
{
monitor_child_pid = pid;
}
static void
monitor_child_handler(int sig)
{
kill(monitor_child_pid, sig);
}
void
monitor_child_postauth(struct ssh *ssh, struct monitor *pmonitor)
{
close(pmonitor->m_recvfd);
pmonitor->m_recvfd = -1;
monitor_set_child_handler(pmonitor->m_pid);
ssh_signal(SIGHUP, &monitor_child_handler);
ssh_signal(SIGTERM, &monitor_child_handler);
ssh_signal(SIGINT, &monitor_child_handler);
#ifdef SIGXFSZ
ssh_signal(SIGXFSZ, SIG_IGN);
#endif
mon_dispatch = mon_dispatch_postauth20;
monitor_permit(mon_dispatch, MONITOR_REQ_STATE, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
if (auth_opts->permit_pty_flag) {
monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
}
for (;;)
monitor_read(ssh, pmonitor, mon_dispatch, NULL);
}
static int
monitor_read_log(struct monitor *pmonitor)
{
struct sshbuf *logmsg;
u_int len, level, forced;
char *msg;
u_char *p;
int r;
if ((logmsg = sshbuf_new()) == NULL)
fatal_f("sshbuf_new");
if ((r = sshbuf_reserve(logmsg, 4, &p)) != 0)
fatal_fr(r, "reserve len");
if (atomicio(read, pmonitor->m_log_recvfd, p, 4) != 4) {
if (errno == EPIPE) {
sshbuf_free(logmsg);
debug_f("child log fd closed");
close(pmonitor->m_log_recvfd);
pmonitor->m_log_recvfd = -1;
return -1;
}
fatal_f("log fd read: %s", strerror(errno));
}
if ((r = sshbuf_get_u32(logmsg, &len)) != 0)
fatal_fr(r, "parse len");
if (len <= 4 || len > 8192)
fatal_f("invalid log message length %u", len);
sshbuf_reset(logmsg);
if ((r = sshbuf_reserve(logmsg, len, &p)) != 0)
fatal_fr(r, "reserve msg");
if (atomicio(read, pmonitor->m_log_recvfd, p, len) != len)
fatal_f("log fd read: %s", strerror(errno));
if ((r = sshbuf_get_u32(logmsg, &level)) != 0 ||
(r = sshbuf_get_u32(logmsg, &forced)) != 0 ||
(r = sshbuf_get_cstring(logmsg, &msg, NULL)) != 0)
fatal_fr(r, "parse");
if (log_level_name(level) == NULL)
fatal_f("invalid log level %u (corrupted message?)", level);
sshlogdirect(level, forced, "%s [%s]", msg,
mon_dispatch == mon_dispatch_postauth20 ? "postauth" : "preauth");
sshbuf_free(logmsg);
free(msg);
return 0;
}
static int
monitor_read(struct ssh *ssh, struct monitor *pmonitor, struct mon_table *ent,
struct mon_table **pent)
{
struct sshbuf *m;
int r, ret;
u_char type;
struct pollfd pfd[2];
for (;;) {
memset(&pfd, 0, sizeof(pfd));
pfd[0].fd = pmonitor->m_sendfd;
pfd[0].events = POLLIN;
pfd[1].fd = pmonitor->m_log_recvfd;
pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
fatal_f("poll: %s", strerror(errno));
}
if (pfd[1].revents) {
monitor_read_log(pmonitor);
continue;
}
if (pfd[0].revents)
break;
}
if ((m = sshbuf_new()) == NULL)
fatal_f("sshbuf_new");
mm_request_receive(pmonitor->m_sendfd, m);
if ((r = sshbuf_get_u8(m, &type)) != 0)
fatal_fr(r, "parse type");
debug3_f("checking request %d", type);
while (ent->f != NULL) {
if (ent->type == type)
break;
ent++;
}
if (ent->f != NULL) {
if (!(ent->flags & MON_PERMIT))
fatal_f("unpermitted request %d", type);
ret = (*ent->f)(ssh, pmonitor->m_sendfd, m);
sshbuf_free(m);
if (ent->flags & MON_ONCE) {
debug2_f("%d used once, disabling now", type);
ent->flags &= ~MON_PERMIT;
}
if (pent != NULL)
*pent = ent;
return ret;
}
fatal_f("unsupported request: %d", type);
return (-1);
}
static int
monitor_allowed_key(const u_char *blob, u_int bloblen)
{
if (key_blob == NULL || key_bloblen != bloblen ||
timingsafe_bcmp(key_blob, blob, key_bloblen))
return (0);
return (1);
}
static void
monitor_reset_key_state(void)
{
free(key_blob);
free(hostbased_cuser);
free(hostbased_chost);
sshauthopt_free(key_opts);
key_blob = NULL;
key_bloblen = 0;
key_blobtype = MM_NOKEY;
key_opts = NULL;
hostbased_cuser = NULL;
hostbased_chost = NULL;
}
int
mm_answer_state(struct ssh *ssh, int sock, struct sshbuf *m)
{
struct sshbuf *inc = NULL, *hostkeys = NULL;
struct sshbuf *opts = NULL, *confdata = NULL;
struct include_item *item = NULL;
int postauth;
int r;
sshbuf_reset(m);
debug_f("config len %zu", sshbuf_len(cfg));
if ((m = sshbuf_new()) == NULL ||
(inc = sshbuf_new()) == NULL ||
(opts = sshbuf_new()) == NULL ||
(confdata = sshbuf_new()) == NULL)
fatal_f("sshbuf_new failed");
TAILQ_FOREACH(item, &includes, entry) {
if ((r = sshbuf_put_cstring(inc, item->selector)) != 0 ||
(r = sshbuf_put_cstring(inc, item->filename)) != 0 ||
(r = sshbuf_put_stringb(inc, item->contents)) != 0)
fatal_fr(r, "compose includes");
}
hostkeys = pack_hostkeys();
if ((r = sshbuf_put_stringb(m, cfg)) != 0 ||
(r = sshbuf_put_u64(m, options.timing_secret)) != 0 ||
(r = sshbuf_put_stringb(m, hostkeys)) != 0 ||
(r = sshbuf_put_stringb(m, ssh->kex->server_version)) != 0 ||
(r = sshbuf_put_stringb(m, ssh->kex->client_version)) != 0 ||
(r = sshbuf_put_stringb(m, inc)) != 0)
fatal_fr(r, "compose config");
postauth = (authctxt && authctxt->pw && authctxt->authenticated);
if (postauth) {
fatal_f("internal error: called in postauth");
}
sshbuf_free(inc);
sshbuf_free(opts);
sshbuf_free(confdata);
mm_request_send(sock, MONITOR_ANS_STATE, m);
debug3_f("done");
return (0);
}
#ifdef WITH_OPENSSL
int
mm_answer_moduli(struct ssh *ssh, int sock, struct sshbuf *m)
{
DH *dh;
const BIGNUM *dh_p, *dh_g;
int r;
u_int min, want, max;
if ((r = sshbuf_get_u32(m, &min)) != 0 ||
(r = sshbuf_get_u32(m, &want)) != 0 ||
(r = sshbuf_get_u32(m, &max)) != 0)
fatal_fr(r, "parse");
debug3_f("got parameters: %d %d %d", min, want, max);
if (max < min || want < min || max < want)
fatal_f("bad parameters: %d %d %d", min, want, max);
sshbuf_reset(m);
dh = choose_dh(min, want, max);
if (dh == NULL) {
if ((r = sshbuf_put_u8(m, 0)) != 0)
fatal_fr(r, "assemble empty");
return (0);
} else {
DH_get0_pqg(dh, &dh_p, NULL, &dh_g);
if ((r = sshbuf_put_u8(m, 1)) != 0 ||
(r = sshbuf_put_bignum2(m, dh_p)) != 0 ||
(r = sshbuf_put_bignum2(m, dh_g)) != 0)
fatal_fr(r, "assemble");
DH_free(dh);
}
mm_request_send(sock, MONITOR_ANS_MODULI, m);
return (0);
}
#endif
int
mm_answer_sign(struct ssh *ssh, int sock, struct sshbuf *m)
{
extern int auth_sock;
struct sshkey *pubkey, *key;
struct sshbuf *sigbuf = NULL;
u_char *p = NULL, *signature = NULL;
char *alg = NULL;
size_t datlen, siglen;
int r, is_proof = 0, keyid;
u_int compat;
const char proof_req[] = "hostkeys-prove-00@openssh.com";
debug3_f("entering");
if ((r = sshkey_froms(m, &pubkey)) != 0 ||
(r = sshbuf_get_string(m, &p, &datlen)) != 0 ||
(r = sshbuf_get_cstring(m, &alg, NULL)) != 0 ||
(r = sshbuf_get_u32(m, &compat)) != 0)
fatal_fr(r, "parse");
if ((keyid = get_hostkey_index(pubkey, 1, ssh)) == -1)
fatal_f("unknown hostkey");
debug_f("hostkey %s index %d", sshkey_ssh_name(pubkey), keyid);
sshkey_free(pubkey);
if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) {
if (session_id2_len == 0)
fatal_f("bad data length: %zu", datlen);
if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL)
fatal_f("no hostkey for index %d", keyid);
if ((sigbuf = sshbuf_new()) == NULL)
fatal_f("sshbuf_new");
if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||
(r = sshbuf_put_string(sigbuf, session_id2,
session_id2_len)) != 0 ||
(r = sshkey_puts(key, sigbuf)) != 0)
fatal_fr(r, "assemble private key proof");
if (datlen != sshbuf_len(sigbuf) ||
memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0)
fatal_f("bad data length: %zu, hostkey proof len %zu",
datlen, sshbuf_len(sigbuf));
sshbuf_free(sigbuf);
is_proof = 1;
}
if (session_id2_len == 0) {
session_id2_len = datlen;
session_id2 = xmalloc(session_id2_len);
memcpy(session_id2, p, session_id2_len);
}
if ((key = get_hostkey_by_index(keyid)) != NULL) {
if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg,
options.sk_provider, NULL, compat)) != 0)
fatal_fr(r, "sign");
} else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL &&
auth_sock > 0) {
if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen,
p, datlen, alg, compat)) != 0)
fatal_fr(r, "agent sign");
} else
fatal_f("no hostkey from index %d", keyid);
debug3_f("%s %s signature len=%zu", alg,
is_proof ? "hostkey proof" : "KEX", siglen);
sshbuf_reset(m);
if ((r = sshbuf_put_string(m, signature, siglen)) != 0)
fatal_fr(r, "assemble");
free(alg);
free(p);
free(signature);
mm_request_send(sock, MONITOR_ANS_SIGN, m);
monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
return (0);
}
#define PUTPW(b, id) \
do { \
if ((r = sshbuf_put_string(b, \
&pwent->id, sizeof(pwent->id))) != 0) \
fatal_fr(r, "assemble %s", #id); \
} while (0)
void
mm_encode_server_options(struct sshbuf *m)
{
int r;
u_int i;
if ((r = sshbuf_put_string(m, &options, sizeof(options))) != 0)
fatal_fr(r, "assemble options");
#define M_CP_STROPT(x) do { \
if (options.x != NULL && \
(r = sshbuf_put_cstring(m, options.x)) != 0) \
fatal_fr(r, "assemble %s", #x); \
} while (0)
#define M_CP_STRARRAYOPT(x, nx) do { \
for (i = 0; i < options.nx; i++) { \
if ((r = sshbuf_put_cstring(m, options.x[i])) != 0) \
fatal_fr(r, "assemble %s", #x); \
} \
} while (0)
COPY_MATCH_STRING_OPTS();
#undef M_CP_STROPT
#undef M_CP_STRARRAYOPT
}
int
mm_answer_pwnamallow(struct ssh *ssh, int sock, struct sshbuf *m)
{
struct passwd *pwent;
int r, allowed = 0;
debug3_f("entering");
if (authctxt->attempt++ != 0)
fatal_f("multiple attempts for getpwnam");
if ((r = sshbuf_get_cstring(m, &authctxt->user, NULL)) != 0)
fatal_fr(r, "parse");
pwent = getpwnamallow(ssh, authctxt->user);
setproctitle("%s [priv]", pwent ? authctxt->user : "unknown");
sshbuf_reset(m);
if (pwent == NULL) {
if ((r = sshbuf_put_u8(m, 0)) != 0)
fatal_fr(r, "assemble fakepw");
authctxt->pw = fakepw();
goto out;
}
allowed = 1;
authctxt->pw = pwent;
authctxt->valid = 1;
if ((r = sshbuf_put_u8(m, 1)) != 0)
fatal_fr(r, "assemble ok");
PUTPW(m, pw_uid);
PUTPW(m, pw_gid);
#ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
PUTPW(m, pw_change);
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
PUTPW(m, pw_expire);
#endif
if ((r = sshbuf_put_cstring(m, pwent->pw_name)) != 0 ||
(r = sshbuf_put_cstring(m, "*")) != 0 ||
#ifdef HAVE_STRUCT_PASSWD_PW_GECOS
(r = sshbuf_put_cstring(m, pwent->pw_gecos)) != 0 ||
#endif
#ifdef HAVE_STRUCT_PASSWD_PW_CLASS
(r = sshbuf_put_cstring(m, pwent->pw_class)) != 0 ||
#endif
(r = sshbuf_put_cstring(m, pwent->pw_dir)) != 0 ||
(r = sshbuf_put_cstring(m, pwent->pw_shell)) != 0)
fatal_fr(r, "assemble pw");
out:
ssh_packet_set_log_preamble(ssh, "%suser %s",
authctxt->valid ? "authenticating" : "invalid ", authctxt->user);
if (options.refuse_connection) {
logit("administratively prohibited connection for "
"%s%s from %.128s port %d",
authctxt->valid ? "" : "invalid user ",
authctxt->user, ssh_remote_ipaddr(ssh),
ssh_remote_port(ssh));
cleanup_exit(EXIT_CONFIG_REFUSED);
}
mm_encode_server_options(m);
if (auth2_setup_methods_lists(authctxt) != 0) {
debug_f("no valid authentication method lists");
}
debug3_f("sending MONITOR_ANS_PWNAM: %d", allowed);
mm_request_send(sock, MONITOR_ANS_PWNAM, m);
monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
#ifdef USE_PAM
if (options.use_pam)
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
#endif
return (0);
}
int mm_answer_auth2_read_banner(struct ssh *ssh, int sock, struct sshbuf *m)
{
char *banner;
int r;
sshbuf_reset(m);
banner = auth2_read_banner();
if ((r = sshbuf_put_cstring(m, banner != NULL ? banner : "")) != 0)
fatal_fr(r, "assemble");
mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
free(banner);
return (0);
}
int
mm_answer_authserv(struct ssh *ssh, int sock, struct sshbuf *m)
{
int r;
monitor_permit_authentications(1);
if ((r = sshbuf_get_cstring(m, &authctxt->service, NULL)) != 0 ||
(r = sshbuf_get_cstring(m, &authctxt->style, NULL)) != 0)
fatal_fr(r, "parse");
debug3_f("service=%s, style=%s", authctxt->service, authctxt->style);
if (strlen(authctxt->style) == 0) {
free(authctxt->style);
authctxt->style = NULL;
}
return (0);
}
static int
key_base_type_match(const char *method, const struct sshkey *key,
const char *list)
{
char *s, *l, *ol = xstrdup(list);
int found = 0;
l = ol;
for ((s = strsep(&l, ",")); s && *s != '\0'; (s = strsep(&l, ","))) {
if (sshkey_type_from_name(s) == key->type) {
found = 1;
break;
}
}
if (!found) {
error("%s key type %s is not in permitted list %s", method,
sshkey_ssh_name(key), list);
}
free(ol);
return found;
}
int
mm_answer_authpassword(struct ssh *ssh, int sock, struct sshbuf *m)
{
static int call_count;
char *passwd;
int r, authenticated;
size_t plen;
if (!options.password_authentication)
fatal_f("password authentication not enabled");
if ((r = sshbuf_get_cstring(m, &passwd, &plen)) != 0)
fatal_fr(r, "parse");
authenticated = options.password_authentication &&
auth_password(ssh, passwd);
freezero(passwd, plen);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, authenticated)) != 0)
fatal_fr(r, "assemble");
#ifdef USE_PAM
if ((r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0)
fatal_fr(r, "assemble PAM");
#endif
debug3("%s: sending result %d", __func__, authenticated);
debug3_f("sending result %d", authenticated);
mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
call_count++;
if (plen == 0 && call_count == 1)
auth_method = "none";
else
auth_method = "password";
return (authenticated);
}
#ifdef BSD_AUTH
int
mm_answer_bsdauthquery(struct ssh *ssh, int sock, struct sshbuf *m)
{
char *name, *infotxt;
u_int numprompts, *echo_on, success;
char **prompts;
int r;
if (!options.kbd_interactive_authentication)
fatal_f("kbd-int authentication not enabled");
success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
&prompts, &echo_on) < 0 ? 0 : 1;
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, success)) != 0)
fatal_fr(r, "assemble");
if (success) {
if ((r = sshbuf_put_cstring(m, prompts[0])) != 0)
fatal_fr(r, "assemble prompt");
}
debug3_f("sending challenge success: %u", success);
mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
if (success) {
free(name);
free(infotxt);
free(prompts);
free(echo_on);
}
return (0);
}
int
mm_answer_bsdauthrespond(struct ssh *ssh, int sock, struct sshbuf *m)
{
char *response;
int r, authok;
if (!options.kbd_interactive_authentication)
fatal_f("kbd-int authentication not enabled");
if (authctxt->as == NULL)
fatal_f("no bsd auth session");
if ((r = sshbuf_get_cstring(m, &response, NULL)) != 0)
fatal_fr(r, "parse");
authok = options.kbd_interactive_authentication &&
auth_userresponse(authctxt->as, response, 0);
authctxt->as = NULL;
debug3_f("<%s> = <%d>", response, authok);
free(response);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, authok)) != 0)
fatal_fr(r, "assemble");
debug3_f("sending authenticated: %d", authok);
mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
auth_method = "keyboard-interactive";
auth_submethod = "bsdauth";
return (authok != 0);
}
#endif
#ifdef USE_PAM
int
mm_answer_pam_start(struct ssh *ssh, int sock, struct sshbuf *m)
{
if (!options.use_pam)
fatal("UsePAM not set, but ended up in %s anyway", __func__);
start_pam(ssh);
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
if (options.kbd_interactive_authentication)
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
return (0);
}
int
mm_answer_pam_account(struct ssh *ssh, int sock, struct sshbuf *m)
{
u_int ret;
int r;
if (!options.use_pam)
fatal("%s: PAM not enabled", __func__);
ret = do_pam_account();
if ((r = sshbuf_put_u32(m, ret)) != 0 ||
(r = sshbuf_put_stringb(m, loginmsg)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
return (ret);
}
static void *sshpam_ctxt, *sshpam_authok;
extern KbdintDevice sshpam_device;
int
mm_answer_pam_init_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
{
u_int ok = 0;
int r;
debug3("%s", __func__);
if (!options.kbd_interactive_authentication)
fatal("%s: kbd-int authentication not enabled", __func__);
if (sshpam_ctxt != NULL)
fatal("%s: already called", __func__);
sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
sshpam_authok = NULL;
sshbuf_reset(m);
if (sshpam_ctxt != NULL) {
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_QUERY, 1);
ok = 1;
}
if ((r = sshbuf_put_u32(m, ok)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
return (0);
}
int
mm_answer_pam_query(struct ssh *ssh, int sock, struct sshbuf *m)
{
char *name = NULL, *info = NULL, **prompts = NULL;
u_int i, num = 0, *echo_on = 0;
int r, ret;
debug3("%s", __func__);
sshpam_authok = NULL;
if (sshpam_ctxt == NULL)
fatal("%s: no context", __func__);
ret = (sshpam_device.query)(sshpam_ctxt, &name, &info,
&num, &prompts, &echo_on);
if (ret == 0 && num == 0)
sshpam_authok = sshpam_ctxt;
if (num > 1 || name == NULL || info == NULL)
fatal("sshpam_device.query failed");
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_RESPOND, 1);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, ret)) != 0 ||
(r = sshbuf_put_cstring(m, name)) != 0 ||
(r = sshbuf_put_cstring(m, info)) != 0 ||
(r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0 ||
(r = sshbuf_put_u32(m, num)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
free(name);
free(info);
for (i = 0; i < num; ++i) {
if ((r = sshbuf_put_cstring(m, prompts[i])) != 0 ||
(r = sshbuf_put_u32(m, echo_on[i])) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
free(prompts[i]);
}
free(prompts);
free(echo_on);
auth_method = "keyboard-interactive";
auth_submethod = "pam";
mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
return (0);
}
int
mm_answer_pam_respond(struct ssh *ssh, int sock, struct sshbuf *m)
{
char **resp;
u_int i, num;
int r, ret;
debug3("%s", __func__);
if (sshpam_ctxt == NULL)
fatal("%s: no context", __func__);
sshpam_authok = NULL;
if ((r = sshbuf_get_u32(m, &num)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (num > PAM_MAX_NUM_MSG) {
fatal_f("Too many PAM messages, got %u, expected <= %u",
num, (unsigned)PAM_MAX_NUM_MSG);
}
if (num > 0) {
resp = xcalloc(num, sizeof(char *));
for (i = 0; i < num; ++i) {
if ((r = sshbuf_get_cstring(m, &(resp[i]), NULL)) != 0)
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
}
ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
for (i = 0; i < num; ++i)
free(resp[i]);
free(resp);
} else {
ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
}
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, ret)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
auth_method = "keyboard-interactive";
auth_submethod = "pam";
if (ret == 0)
sshpam_authok = sshpam_ctxt;
return (0);
}
int
mm_answer_pam_free_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
{
int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt;
debug3("%s", __func__);
if (sshpam_ctxt == NULL)
fatal("%s: no context", __func__);
(sshpam_device.free_ctx)(sshpam_ctxt);
sshpam_ctxt = sshpam_authok = NULL;
sshbuf_reset(m);
mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
auth_method = "keyboard-interactive";
auth_submethod = "pam";
return r;
}
#endif
int
mm_answer_keyallowed(struct ssh *ssh, int sock, struct sshbuf *m)
{
struct sshkey *key = NULL;
char *cuser, *chost;
u_int pubkey_auth_attempt;
u_int type = 0;
int r, allowed = 0;
struct sshauthopt *opts = NULL;
debug3_f("entering");
if ((r = sshbuf_get_u32(m, &type)) != 0 ||
(r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 ||
(r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
(r = sshkey_froms(m, &key)) != 0 ||
(r = sshbuf_get_u32(m, &pubkey_auth_attempt)) != 0)
fatal_fr(r, "parse");
if (key != NULL && authctxt->valid) {
switch (type) {
case MM_USERKEY:
auth_method = "publickey";
if (!options.pubkey_authentication)
break;
if (auth2_key_already_used(authctxt, key))
break;
if (!key_base_type_match(auth_method, key,
options.pubkey_accepted_algos))
break;
allowed = user_key_allowed(ssh, authctxt->pw, key,
pubkey_auth_attempt, &opts);
break;
case MM_HOSTKEY:
auth_method = "hostbased";
if (!options.hostbased_authentication)
break;
if (auth2_key_already_used(authctxt, key))
break;
if (!key_base_type_match(auth_method, key,
options.hostbased_accepted_algos))
break;
allowed = hostbased_key_allowed(ssh, authctxt->pw,
cuser, chost, key);
auth2_record_info(authctxt,
"client user \"%.100s\", client host \"%.100s\"",
cuser, chost);
break;
default:
fatal_f("unknown key type %u", type);
break;
}
}
debug3_f("%s authentication%s: %s key is %s", auth_method,
pubkey_auth_attempt ? "" : " test",
(key == NULL || !authctxt->valid) ? "invalid" : sshkey_type(key),
allowed ? "allowed" : "not allowed");
auth2_record_key(authctxt, 0, key);
monitor_reset_key_state();
if (allowed) {
if ((r = sshkey_to_blob(key, &key_blob, &key_bloblen)) != 0)
fatal_fr(r, "sshkey_to_blob");
key_blobtype = type;
key_opts = opts;
hostbased_cuser = cuser;
hostbased_chost = chost;
} else {
auth_log(ssh, 0, 0, auth_method, NULL);
free(cuser);
free(chost);
}
sshkey_free(key);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, allowed)) != 0)
fatal_fr(r, "assemble");
if (opts != NULL && (r = sshauthopt_serialise(opts, m, 1)) != 0)
fatal_fr(r, "sshauthopt_serialise");
mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
if (!allowed)
sshauthopt_free(opts);
return (0);
}
static int
monitor_valid_userblob(struct ssh *ssh, const u_char *data, u_int datalen)
{
struct sshbuf *b;
struct sshkey *hostkey = NULL;
const u_char *p;
char *userstyle, *cp;
size_t len;
u_char type;
int hostbound = 0, r, fail = 0;
if ((b = sshbuf_from(data, datalen)) == NULL)
fatal_f("sshbuf_from");
if (ssh->compat & SSH_OLD_SESSIONID) {
p = sshbuf_ptr(b);
len = sshbuf_len(b);
if ((session_id2 == NULL) ||
(len < session_id2_len) ||
(timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
fail++;
if ((r = sshbuf_consume(b, session_id2_len)) != 0)
fatal_fr(r, "consume");
} else {
if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
fatal_fr(r, "parse sessionid");
if ((session_id2 == NULL) ||
(len != session_id2_len) ||
(timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
fail++;
}
if ((r = sshbuf_get_u8(b, &type)) != 0)
fatal_fr(r, "parse type");
if (type != SSH2_MSG_USERAUTH_REQUEST)
fail++;
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
fatal_fr(r, "parse userstyle");
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
if (strcmp(userstyle, cp) != 0) {
logit("wrong user name passed to monitor: "
"expected %s != %.100s", userstyle, cp);
fail++;
}
free(userstyle);
free(cp);
if ((r = sshbuf_skip_string(b)) != 0 ||
(r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
fatal_fr(r, "parse method");
if (strcmp("publickey", cp) != 0) {
if (strcmp("publickey-hostbound-v00@openssh.com", cp) == 0)
hostbound = 1;
else
fail++;
}
free(cp);
if ((r = sshbuf_get_u8(b, &type)) != 0)
fatal_fr(r, "parse pktype");
if (type == 0)
fail++;
if ((r = sshbuf_skip_string(b)) != 0 ||
(r = sshbuf_skip_string(b)) != 0 ||
(hostbound && (r = sshkey_froms(b, &hostkey)) != 0))
fatal_fr(r, "parse pk");
if (sshbuf_len(b) != 0)
fail++;
sshbuf_free(b);
if (hostkey != NULL) {
if (get_hostkey_index(hostkey, 1, ssh) == -1)
fatal_f("hostbound hostkey does not match");
sshkey_free(hostkey);
}
return (fail == 0);
}
static int
monitor_valid_hostbasedblob(const u_char *data, u_int datalen,
const char *cuser, const char *chost)
{
struct sshbuf *b;
const u_char *p;
char *cp, *userstyle;
size_t len;
int r, fail = 0;
u_char type;
if ((b = sshbuf_from(data, datalen)) == NULL)
fatal_f("sshbuf_new");
if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
fatal_fr(r, "parse sessionid");
if ((session_id2 == NULL) ||
(len != session_id2_len) ||
(timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
fail++;
if ((r = sshbuf_get_u8(b, &type)) != 0)
fatal_fr(r, "parse type");
if (type != SSH2_MSG_USERAUTH_REQUEST)
fail++;
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
fatal_fr(r, "parse userstyle");
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
if (strcmp(userstyle, cp) != 0) {
logit("wrong user name passed to monitor: "
"expected %s != %.100s", userstyle, cp);
fail++;
}
free(userstyle);
free(cp);
if ((r = sshbuf_skip_string(b)) != 0 ||
(r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
fatal_fr(r, "parse method");
if (strcmp(cp, "hostbased") != 0)
fail++;
free(cp);
if ((r = sshbuf_skip_string(b)) != 0 ||
(r = sshbuf_skip_string(b)) != 0)
fatal_fr(r, "parse pk");
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
fatal_fr(r, "parse host");
if (((len = strlen(cp)) > 0) && cp[len - 1] == '.')
cp[len - 1] = '\0';
if (strcmp(cp, chost) != 0)
fail++;
free(cp);
if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
fatal_fr(r, "parse ruser");
if (strcmp(cp, cuser) != 0)
fail++;
free(cp);
if (sshbuf_len(b) != 0)
fail++;
sshbuf_free(b);
return (fail == 0);
}
int
mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m)
{
struct sshkey *key;
const u_char *signature, *data, *blob;
char *sigalg = NULL, *fp = NULL;
size_t signaturelen, datalen, bloblen;
int r, ret, req_presence = 0, req_verify = 0, valid_data = 0;
int encoded_ret;
struct sshkey_sig_details *sig_details = NULL;
if ((r = sshbuf_get_string_direct(m, &blob, &bloblen)) != 0 ||
(r = sshbuf_get_string_direct(m, &signature, &signaturelen)) != 0 ||
(r = sshbuf_get_string_direct(m, &data, &datalen)) != 0 ||
(r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0)
fatal_fr(r, "parse");
if (hostbased_cuser == NULL || hostbased_chost == NULL ||
!monitor_allowed_key(blob, bloblen))
fatal_f("bad key, not previously allowed");
if (*sigalg == '\0') {
free(sigalg);
sigalg = NULL;
}
if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
fatal_fr(r, "parse key");
switch (key_blobtype) {
case MM_USERKEY:
valid_data = monitor_valid_userblob(ssh, data, datalen);
auth_method = "publickey";
break;
case MM_HOSTKEY:
valid_data = monitor_valid_hostbasedblob(data, datalen,
hostbased_cuser, hostbased_chost);
auth_method = "hostbased";
break;
default:
valid_data = 0;
break;
}
if (!valid_data)
fatal_f("bad %s signature data blob",
key_blobtype == MM_USERKEY ? "userkey" :
(key_blobtype == MM_HOSTKEY ? "hostkey" : "unknown"));
if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
SSH_FP_DEFAULT)) == NULL)
fatal_f("sshkey_fingerprint failed");
ret = sshkey_verify(key, signature, signaturelen, data, datalen,
sigalg, ssh->compat, &sig_details);
debug3_f("%s %s signature using %s %s%s%s", auth_method,
sshkey_type(key), sigalg == NULL ? "default" : sigalg,
(ret == 0) ? "verified" : "unverified",
(ret != 0) ? ": " : "", (ret != 0) ? ssh_err(ret) : "");
if (ret == 0 && key_blobtype == MM_USERKEY && sig_details != NULL) {
req_presence = (options.pubkey_auth_options &
PUBKEYAUTH_TOUCH_REQUIRED) ||
!key_opts->no_require_user_presence;
if (req_presence &&
(sig_details->sk_flags & SSH_SK_USER_PRESENCE_REQD) == 0) {
error("public key %s %s signature for %s%s from %.128s "
"port %d rejected: user presence "
"(authenticator touch) requirement not met ",
sshkey_type(key), fp,
authctxt->valid ? "" : "invalid user ",
authctxt->user, ssh_remote_ipaddr(ssh),
ssh_remote_port(ssh));
ret = SSH_ERR_SIGNATURE_INVALID;
}
req_verify = (options.pubkey_auth_options &
PUBKEYAUTH_VERIFY_REQUIRED) || key_opts->require_verify;
if (req_verify &&
(sig_details->sk_flags & SSH_SK_USER_VERIFICATION_REQD) == 0) {
error("public key %s %s signature for %s%s from %.128s "
"port %d rejected: user verification requirement "
"not met ", sshkey_type(key), fp,
authctxt->valid ? "" : "invalid user ",
authctxt->user, ssh_remote_ipaddr(ssh),
ssh_remote_port(ssh));
ret = SSH_ERR_SIGNATURE_INVALID;
}
}
auth2_record_key(authctxt, ret == 0, key);
if (key_blobtype == MM_USERKEY && ret == 0)
auth_activate_options(ssh, key_opts);
monitor_reset_key_state();
sshbuf_reset(m);
encoded_ret = (ret != 0);
if ((r = sshbuf_put_u32(m, encoded_ret)) != 0 ||
(r = sshbuf_put_u8(m, sig_details != NULL)) != 0)
fatal_fr(r, "assemble");
if (sig_details != NULL) {
if ((r = sshbuf_put_u32(m, sig_details->sk_counter)) != 0 ||
(r = sshbuf_put_u8(m, sig_details->sk_flags)) != 0)
fatal_fr(r, "assemble sk");
}
sshkey_sig_details_free(sig_details);
mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
free(sigalg);
free(fp);
sshkey_free(key);
return ret == 0;
}
static void
mm_record_login(struct ssh *ssh, Session *s, struct passwd *pw)
{
socklen_t fromlen;
struct sockaddr_storage from;
memset(&from, 0, sizeof(from));
fromlen = sizeof(from);
if (ssh_packet_connection_is_on_socket(ssh)) {
if (getpeername(ssh_packet_get_connection_in(ssh),
(struct sockaddr *)&from, &fromlen) == -1) {
debug("getpeername: %.100s", strerror(errno));
cleanup_exit(255);
}
}
record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns),
(struct sockaddr *)&from, fromlen);
}
static void
mm_session_close(Session *s)
{
debug3_f("session %d pid %ld", s->self, (long)s->pid);
if (s->ttyfd != -1) {
debug3_f("tty %s ptyfd %d", s->tty, s->ptyfd);
session_pty_cleanup2(s);
}
session_unused(s->self);
}
int
mm_answer_pty(struct ssh *ssh, int sock, struct sshbuf *m)
{
extern struct monitor *pmonitor;
Session *s;
int r, res, fd0;
debug3_f("entering");
sshbuf_reset(m);
s = session_new();
if (s == NULL)
goto error;
s->authctxt = authctxt;
s->pw = authctxt->pw;
s->pid = pmonitor->m_pid;
res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
if (res == 0)
goto error;
pty_setowner(authctxt->pw, s->tty);
if ((r = sshbuf_put_u32(m, 1)) != 0 ||
(r = sshbuf_put_cstring(m, s->tty)) != 0)
fatal_fr(r, "assemble");
if (dup2(s->ttyfd, 0) == -1)
fatal_f("dup2");
mm_record_login(ssh, s, authctxt->pw);
close(0);
if ((r = sshbuf_put_stringb(m, loginmsg)) != 0)
fatal_fr(r, "assemble loginmsg");
sshbuf_reset(loginmsg);
mm_request_send(sock, MONITOR_ANS_PTY, m);
if (mm_send_fd(sock, s->ptyfd) == -1 ||
mm_send_fd(sock, s->ttyfd) == -1)
fatal_f("send fds failed");
if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) == -1)
fatal_f("open(/dev/null): %s", strerror(errno));
if (fd0 != 0)
error_f("fd0 %d != 0", fd0);
close(s->ttyfd);
s->ttyfd = s->ptyfd;
s->ptymaster = s->ptyfd;
debug3_f("tty %s ptyfd %d", s->tty, s->ttyfd);
return (0);
error:
if (s != NULL)
mm_session_close(s);
if ((r = sshbuf_put_u32(m, 0)) != 0)
fatal_fr(r, "assemble 0");
mm_request_send(sock, MONITOR_ANS_PTY, m);
return (0);
}
int
mm_answer_pty_cleanup(struct ssh *ssh, int sock, struct sshbuf *m)
{
Session *s;
char *tty;
int r;
debug3_f("entering");
if ((r = sshbuf_get_cstring(m, &tty, NULL)) != 0)
fatal_fr(r, "parse tty");
if ((s = session_by_tty(tty)) != NULL)
mm_session_close(s);
sshbuf_reset(m);
free(tty);
return (0);
}
int
mm_answer_term(struct ssh *ssh, int sock, struct sshbuf *req)
{
extern struct monitor *pmonitor;
int res, status;
debug3_f("tearing down sessions");
session_destroy_all(ssh, &mm_session_close);
#ifdef USE_PAM
if (options.use_pam)
sshpam_cleanup();
#endif
while (waitpid(pmonitor->m_pid, &status, 0) == -1)
if (errno != EINTR)
exit(1);
res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
exit(res);
}
#ifdef SSH_AUDIT_EVENTS
int
mm_answer_audit_event(struct ssh *ssh, int socket, struct sshbuf *m)
{
u_int n;
ssh_audit_event_t event;
int r;
debug3("%s entering", __func__);
if ((r = sshbuf_get_u32(m, &n)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
event = (ssh_audit_event_t)n;
switch (event) {
case SSH_AUTH_FAIL_PUBKEY:
case SSH_AUTH_FAIL_HOSTBASED:
case SSH_AUTH_FAIL_GSSAPI:
case SSH_LOGIN_EXCEED_MAXTRIES:
case SSH_LOGIN_ROOT_DENIED:
case SSH_CONNECTION_CLOSE:
case SSH_INVALID_USER:
audit_event(ssh, event);
break;
default:
fatal("Audit event type %d not permitted", event);
}
return (0);
}
int
mm_answer_audit_command(struct ssh *ssh, int socket, struct sshbuf *m)
{
char *cmd;
int r;
debug3("%s entering", __func__);
if ((r = sshbuf_get_cstring(m, &cmd, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
audit_run_command(cmd);
free(cmd);
return (0);
}
#endif
void
monitor_clear_keystate(struct ssh *ssh, struct monitor *pmonitor)
{
ssh_clear_newkeys(ssh, MODE_IN);
ssh_clear_newkeys(ssh, MODE_OUT);
sshbuf_free(child_state);
child_state = NULL;
}
void
monitor_apply_keystate(struct ssh *ssh, struct monitor *pmonitor)
{
struct kex *kex;
int r;
debug3_f("packet_set_state");
if ((r = ssh_packet_set_state(ssh, child_state)) != 0)
fatal_fr(r, "packet_set_state");
sshbuf_free(child_state);
child_state = NULL;
if ((kex = ssh->kex) == NULL)
fatal_f("internal error: ssh->kex == NULL");
if (session_id2_len != sshbuf_len(ssh->kex->session_id)) {
fatal_f("incorrect session id length %zu (expected %u)",
sshbuf_len(ssh->kex->session_id), session_id2_len);
}
if (memcmp(sshbuf_ptr(ssh->kex->session_id), session_id2,
session_id2_len) != 0)
fatal_f("session ID mismatch");
#ifdef WITH_OPENSSL
kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server;
kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server;
kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server;
kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
# ifdef OPENSSL_HAS_ECC
kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
# endif
#endif
kex->kex[KEX_C25519_SHA256] = kex_gen_server;
kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
kex->kex[KEX_KEM_MLKEM768X25519_SHA256] = kex_gen_server;
kex->load_host_public_key=&get_hostkey_public_by_type;
kex->load_host_private_key=&get_hostkey_private_by_type;
kex->host_key_index=&get_hostkey_index;
kex->sign = sshd_hostkey_sign;
}
void
mm_get_keystate(struct ssh *ssh, struct monitor *pmonitor)
{
debug3_f("Waiting for new keys");
if ((child_state = sshbuf_new()) == NULL)
fatal_f("sshbuf_new failed");
mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT,
child_state);
debug3_f("GOT new keys");
}
#define FD_CLOSEONEXEC(x) do { \
if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
fatal("fcntl(%d, F_SETFD)", x); \
} while (0)
static void
monitor_openfds(struct monitor *mon, int do_logfds)
{
int pair[2];
#ifdef SO_ZEROIZE
int on = 1;
#endif
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
fatal_f("socketpair: %s", strerror(errno));
#ifdef SO_ZEROIZE
if (setsockopt(pair[0], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
error("setsockopt SO_ZEROIZE(0): %.100s", strerror(errno));
if (setsockopt(pair[1], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
error("setsockopt SO_ZEROIZE(1): %.100s", strerror(errno));
#endif
FD_CLOSEONEXEC(pair[0]);
FD_CLOSEONEXEC(pair[1]);
mon->m_recvfd = pair[0];
mon->m_sendfd = pair[1];
if (do_logfds) {
if (pipe(pair) == -1)
fatal_f("pipe: %s", strerror(errno));
FD_CLOSEONEXEC(pair[0]);
FD_CLOSEONEXEC(pair[1]);
mon->m_log_recvfd = pair[0];
mon->m_log_sendfd = pair[1];
} else
mon->m_log_recvfd = mon->m_log_sendfd = -1;
}
struct monitor *
monitor_init(void)
{
struct monitor *mon;
mon = xcalloc(1, sizeof(*mon));
monitor_openfds(mon, 1);
return mon;
}
void
monitor_reinit(struct monitor *mon)
{
monitor_openfds(mon, 0);
}
#ifdef GSSAPI
int
mm_answer_gss_setup_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
{
gss_OID_desc goid;
OM_uint32 major;
size_t len;
u_char *p;
int r;
if (!options.gss_authentication)
fatal_f("GSSAPI authentication not enabled");
if ((r = sshbuf_get_string(m, &p, &len)) != 0)
fatal_fr(r, "parse");
goid.elements = p;
goid.length = len;
major = ssh_gssapi_server_ctx(&gsscontext, &goid);
free(goid.elements);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, major)) != 0)
fatal_fr(r, "assemble");
mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
return (0);
}
int
mm_answer_gss_accept_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
{
gss_buffer_desc in;
gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
OM_uint32 major, minor;
OM_uint32 flags = 0;
int r;
if (!options.gss_authentication)
fatal_f("GSSAPI authentication not enabled");
if ((r = ssh_gssapi_get_buffer_desc(m, &in)) != 0)
fatal_fr(r, "ssh_gssapi_get_buffer_desc");
major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
free(in.value);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, major)) != 0 ||
(r = sshbuf_put_string(m, out.value, out.length)) != 0 ||
(r = sshbuf_put_u32(m, flags)) != 0)
fatal_fr(r, "assemble");
mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
gss_release_buffer(&minor, &out);
if (major == GSS_S_COMPLETE) {
monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
}
return (0);
}
int
mm_answer_gss_checkmic(struct ssh *ssh, int sock, struct sshbuf *m)
{
gss_buffer_desc gssbuf, mic;
OM_uint32 ret;
int r;
if (!options.gss_authentication)
fatal_f("GSSAPI authentication not enabled");
if ((r = ssh_gssapi_get_buffer_desc(m, &gssbuf)) != 0 ||
(r = ssh_gssapi_get_buffer_desc(m, &mic)) != 0)
fatal_fr(r, "ssh_gssapi_get_buffer_desc");
ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
free(gssbuf.value);
free(mic.value);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, ret)) != 0)
fatal_fr(r, "assemble");
mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
if (!GSS_ERROR(ret))
monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
return (0);
}
int
mm_answer_gss_userok(struct ssh *ssh, int sock, struct sshbuf *m)
{
int r, authenticated;
const char *displayname;
if (!options.gss_authentication)
fatal_f("GSSAPI authentication not enabled");
authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, authenticated)) != 0)
fatal_fr(r, "assemble");
debug3_f("sending result %d", authenticated);
mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
auth_method = "gssapi-with-mic";
if ((displayname = ssh_gssapi_displayname()) != NULL)
auth2_record_info(authctxt, "%s", displayname);
return (authenticated);
}
#endif
