From c00e4d75528cf5c1cc803c798459d56ae614ea1f Mon Sep 17 00:00:00 2001 From: dtucker Date: Wed, 2 Feb 2005 13:20:53 +0000 Subject: [PATCH] - (dtucker) [Makefile.in auth.c auth.h auth1.c auth2.c loginrec.c monitor.c monitor.h monitor_wrap.c monitor_wrap.h session.c sshd.c] Bug #125: (first stage) Add audit instrumentation to sshd, currently disabled by default. with suggestions from and djm@ --- ChangeLog | 4 ++++ Makefile.in | 2 +- auth.c | 42 ++++++++++++++++++++++++++++++++ auth.h | 1 + auth1.c | 12 ++++++++-- auth2.c | 15 ++++++++++-- loginrec.c | 7 ++++++ monitor.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++ monitor.h | 1 + monitor_wrap.c | 30 +++++++++++++++++++++++ monitor_wrap.h | 6 +++++ session.c | 16 +++++++++++++ sshd.c | 12 ++++++++++ 13 files changed, 208 insertions(+), 5 deletions(-) diff --git a/ChangeLog b/ChangeLog index 1f676b5c..908b4493 100644 --- a/ChangeLog +++ b/ChangeLog @@ -14,6 +14,10 @@ attempts (currently only for password, kbdint and C/R, only on Linux and HP-UX), based on code from login.c from util-linux. With ashok_kovai at hotmail.com, ok djm@ + - (dtucker) [Makefile.in auth.c auth.h auth1.c auth2.c loginrec.c monitor.c + monitor.h monitor_wrap.c monitor_wrap.h session.c sshd.c] Bug #125: + (first stage) Add audit instrumentation to sshd, currently disabled by + default. with suggestions from and djm@ 20050201 - (dtucker) [log.c] Bug #973: force log_init() to open syslog, since on some diff --git a/Makefile.in b/Makefile.in index d0f27afb..b2e33336 100644 --- a/Makefile.in +++ b/Makefile.in @@ -85,7 +85,7 @@ SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o auth-rsa.o auth-rh-rsa.o \ monitor_mm.o monitor.o monitor_wrap.o kexdhs.o kexgexs.o \ auth-krb5.o \ auth2-gss.o gss-serv.o gss-serv-krb5.o \ - loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o + loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o audit.o MANPAGES = scp.1.out ssh-add.1.out ssh-agent.1.out ssh-keygen.1.out ssh-keyscan.1.out ssh.1.out sshd.8.out sftp-server.8.out sftp.1.out ssh-rand-helper.8.out ssh-keysign.8.out sshd_config.5.out ssh_config.5.out MANPAGES_IN = scp.1 ssh-add.1 ssh-agent.1 ssh-keygen.1 ssh-keyscan.1 ssh.1 sshd.8 sftp-server.8 sftp.1 ssh-rand-helper.8 ssh-keysign.8 sshd_config.5 ssh_config.5 diff --git a/auth.c b/auth.c index b6c00c12..bbf3a54a 100644 --- a/auth.c +++ b/auth.c @@ -51,6 +51,7 @@ RCSID("$OpenBSD: auth.c,v 1.57 2005/01/22 08:17:59 dtucker Exp $"); #include "bufaux.h" #include "packet.h" #include "loginrec.h" +#include "monitor_wrap.h" /* import */ extern ServerOptions options; @@ -251,6 +252,44 @@ auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) record_failed_login(authctxt->user, get_canonical_hostname(options.use_dns), "ssh"); #endif +#ifdef AUDIT_EVENTS + if (authenticated == 0 && !authctxt->postponed) { + ssh_audit_event_t event; + + debug3("audit failed auth attempt, method %s euid %d", + method, (int)geteuid()); + /* + * Because the auth loop is used in both monitor and slave, + * we must be careful to send each event only once and with + * enough privs to write the event. + */ + event = audit_classify_auth(method); + switch(event) { + case AUTH_FAIL_NONE: + case AUTH_FAIL_PASSWD: + case AUTH_FAIL_KBDINT: + if (geteuid() == 0) + audit_event(event); + break; + case AUTH_FAIL_PUBKEY: + case AUTH_FAIL_HOSTBASED: + case AUTH_FAIL_GSSAPI: + /* + * This is required to handle the case where privsep + * is enabled but it's root logging in, since + * use_privsep won't be cleared until after a + * successful login. + */ + if (geteuid() == 0) + audit_event(event); + else + PRIVSEP(audit_event(event)); + break; + default: + error("unknown authentication audit event %d", event); + } + } +#endif } /* @@ -476,6 +515,9 @@ getpwnamallow(const char *user) record_failed_login(user, get_canonical_hostname(options.use_dns), "ssh"); #endif +#ifdef AUDIT_EVENTS + audit_event(INVALID_USER); +#endif /* AUDIT_EVENTS */ return (NULL); } if (!allowed_user(pw)) diff --git a/auth.h b/auth.h index 6c0089dc..8d1f9340 100644 --- a/auth.h +++ b/auth.h @@ -130,6 +130,7 @@ int auth_shadow_pwexpired(Authctxt *); #endif #include "auth-pam.h" +#include "audit.h" void remove_kbdint_device(const char *); void disable_forwarding(void); diff --git a/auth1.c b/auth1.c index 2a9d18b9..aeb5d8cb 100644 --- a/auth1.c +++ b/auth1.c @@ -247,8 +247,12 @@ do_authloop(Authctxt *authctxt) #else /* Special handling for root */ if (authenticated && authctxt->pw->pw_uid == 0 && - !auth_root_allowed(get_authname(type))) + !auth_root_allowed(get_authname(type))) { authenticated = 0; +# ifdef AUDIT_EVENTS + PRIVSEP(audit_event(LOGIN_ROOT_DENIED)); +# endif + } #endif #ifdef USE_PAM @@ -283,8 +287,12 @@ do_authloop(Authctxt *authctxt) if (authenticated) return; - if (authctxt->failures++ > options.max_authtries) + if (authctxt->failures++ > options.max_authtries) { +#ifdef AUDIT_EVENTS + PRIVSEP(audit_event(LOGIN_EXCEED_MAXTRIES)); +#endif packet_disconnect(AUTH_FAIL_MSG, authctxt->user); + } packet_start(SSH_SMSG_FAILURE); packet_send(); diff --git a/auth2.c b/auth2.c index 60e261f7..2727e0ff 100644 --- a/auth2.c +++ b/auth2.c @@ -166,6 +166,9 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt) #ifdef USE_PAM if (options.use_pam) PRIVSEP(start_pam(authctxt)); +#endif +#ifdef AUDIT_EVENTS + PRIVSEP(audit_event(INVALID_USER)); #endif } setproctitle("%s%s", authctxt->valid ? user : "unknown", @@ -214,8 +217,12 @@ userauth_finish(Authctxt *authctxt, int authenticated, char *method) /* Special handling for root */ if (authenticated && authctxt->pw->pw_uid == 0 && - !auth_root_allowed(method)) + !auth_root_allowed(method)) { authenticated = 0; +#ifdef AUDIT_EVENTS + PRIVSEP(audit_event(LOGIN_ROOT_DENIED)); +#endif + } #ifdef USE_PAM if (options.use_pam && authenticated) { @@ -255,8 +262,12 @@ userauth_finish(Authctxt *authctxt, int authenticated, char *method) /* now we can break out */ authctxt->success = 1; } else { - if (authctxt->failures++ > options.max_authtries) + if (authctxt->failures++ > options.max_authtries) { +#ifdef AUDIT_EVENTS + PRIVSEP(audit_event(LOGIN_EXCEED_MAXTRIES)); +#endif packet_disconnect(AUTH_FAIL_MSG, authctxt->user); + } methods = authmethods_get(); packet_start(SSH2_MSG_USERAUTH_FAILURE); packet_put_cstring(methods); diff --git a/loginrec.c b/loginrec.c index 491b7afb..f87492a6 100644 --- a/loginrec.c +++ b/loginrec.c @@ -154,6 +154,7 @@ #include "atomicio.h" #include "packet.h" #include "canohost.h" +#include "auth.h" #ifdef HAVE_UTIL_H # include @@ -442,6 +443,12 @@ login_write(struct logininfo *li) if (li->type == LTYPE_LOGIN && !sys_auth_record_login(li->username,li->hostname,li->line)) logit("Writing login record failed for %s", li->username); +#endif +#ifdef AUDIT_EVENTS + if (li->type == LTYPE_LOGIN) + audit_session_open(li->line); + else if (li->type == LTYPE_LOGOUT) + audit_session_close(li->line); #endif return (0); } diff --git a/monitor.c b/monitor.c index 00d4a785..ce7784aa 100644 --- a/monitor.c +++ b/monitor.c @@ -143,6 +143,11 @@ int mm_answer_gss_userok(int, Buffer *); int mm_answer_gss_checkmic(int, Buffer *); #endif +#ifdef AUDIT_EVENTS +int mm_answer_audit_event(int, Buffer *); +int mm_answer_audit_command(int, Buffer *); +#endif + static Authctxt *authctxt; static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ @@ -186,6 +191,9 @@ struct mon_table mon_dispatch_proto20[] = { {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, #endif +#ifdef AUDIT_EVENTS + {MONITOR_REQ_AUDIT_EVENT, 0, mm_answer_audit_event}, +#endif #ifdef BSD_AUTH {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond}, @@ -211,6 +219,10 @@ struct mon_table mon_dispatch_postauth20[] = { {MONITOR_REQ_PTY, 0, mm_answer_pty}, {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup}, {MONITOR_REQ_TERM, 0, mm_answer_term}, +#ifdef 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} }; @@ -238,6 +250,9 @@ struct mon_table mon_dispatch_proto15[] = { {MONITOR_REQ_PAM_QUERY, MON_ISAUTH, mm_answer_pam_query}, {MONITOR_REQ_PAM_RESPOND, MON_ISAUTH, mm_answer_pam_respond}, {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx}, +#endif +#ifdef AUDIT_EVENTS + {MONITOR_REQ_AUDIT_EVENT, 0, mm_answer_audit_event}, #endif {0, 0, NULL} }; @@ -246,6 +261,10 @@ struct mon_table mon_dispatch_postauth15[] = { {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty}, {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup}, {MONITOR_REQ_TERM, 0, mm_answer_term}, +#ifdef AUDIT_EVENTS + {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, + {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT|MON_ONCE, mm_answer_audit_command}, +#endif {0, 0, NULL} }; @@ -609,6 +628,9 @@ mm_answer_pwnamallow(int sock, Buffer *m) if (options.use_pam) monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1); #endif +#ifdef AUDIT_EVENTS + monitor_permit(mon_dispatch, MONITOR_REQ_AUDIT_EVENT, 1); +#endif return (0); } @@ -1491,6 +1513,49 @@ mm_answer_term(int sock, Buffer *req) exit(res); } +#ifdef AUDIT_EVENTS +/* Report that an audit event occurred */ +int +mm_answer_audit_event(int socket, Buffer *m) +{ + ssh_audit_event_t event; + + debug3("%s entering", __func__); + + event = buffer_get_int(m); + buffer_free(m); + switch(event) { + case AUTH_FAIL_PUBKEY: + case AUTH_FAIL_HOSTBASED: + case AUTH_FAIL_GSSAPI: + case LOGIN_EXCEED_MAXTRIES: + case LOGIN_ROOT_DENIED: + case CONNECTION_CLOSE: + audit_event(event); + break; + default: + fatal("Audit event type %d not permitted", event); + } + + return (0); +} + +int +mm_answer_audit_command(int socket, Buffer *m) +{ + u_int len; + char *cmd; + + debug3("%s entering", __func__); + cmd = buffer_get_string(m, &len); + /* sanity check command, if so how? */ + audit_run_command(cmd); + xfree(cmd); + buffer_free(m); + return (0); +} +#endif /* AUDIT_EVENTS */ + void monitor_apply_keystate(struct monitor *pmonitor) { diff --git a/monitor.h b/monitor.h index 621a4ad1..13ce3e1c 100644 --- a/monitor.h +++ b/monitor.h @@ -59,6 +59,7 @@ enum monitor_reqtype { MONITOR_REQ_PAM_QUERY, MONITOR_ANS_PAM_QUERY, MONITOR_REQ_PAM_RESPOND, MONITOR_ANS_PAM_RESPOND, MONITOR_REQ_PAM_FREE_CTX, MONITOR_ANS_PAM_FREE_CTX, + MONITOR_REQ_AUDIT_EVENT, MONITOR_REQ_AUDIT_COMMAND, MONITOR_REQ_TERM }; diff --git a/monitor_wrap.c b/monitor_wrap.c index 23857639..983b2407 100644 --- a/monitor_wrap.c +++ b/monitor_wrap.c @@ -1103,6 +1103,36 @@ mm_auth_rsa_verify_response(Key *key, BIGNUM *p, u_char response[16]) return (success); } +#ifdef AUDIT_EVENTS +void +mm_audit_event(ssh_audit_event_t event) +{ + Buffer m; + + debug3("%s entering", __func__); + + buffer_init(&m); + buffer_put_int(&m, event); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_EVENT, &m); + buffer_free(&m); +} + +void +mm_audit_run_command(const char *command) +{ + Buffer m; + + debug3("%s entering command %s", __func__, command); + + buffer_init(&m); + buffer_put_cstring(&m, command); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, &m); + buffer_free(&m); +} +#endif /* AUDIT_EVENTS */ + #ifdef GSSAPI OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid) diff --git a/monitor_wrap.h b/monitor_wrap.h index e5cf5718..7ed241aa 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -74,6 +74,12 @@ int mm_sshpam_respond(void *, u_int, char **); void mm_sshpam_free_ctx(void *); #endif +#ifdef AUDIT_EVENTS +#include "audit.h" +void mm_audit_event(ssh_audit_event_t); +void mm_audit_run_command(const char *); +#endif + struct Session; void mm_terminate(void); int mm_pty_allocate(int *, int *, char *, int); diff --git a/session.c b/session.c index 4d7ac9de..b645144c 100644 --- a/session.c +++ b/session.c @@ -665,6 +665,18 @@ do_exec(Session *s, const char *command) debug("Forced command '%.900s'", command); } +#ifdef AUDIT_EVENTS + if (command != NULL) + PRIVSEP(audit_run_command(command)); + else if (s->ttyfd == -1) { + char *shell = s->pw->pw_shell; + + if (shell[0] == '\0') /* empty shell means /bin/sh */ + shell =_PATH_BSHELL; + PRIVSEP(audit_run_command(shell)); + } +#endif + #ifdef GSSAPI if (options.gss_authentication) { temporarily_use_uid(s->pw); @@ -2321,6 +2333,10 @@ do_cleanup(Authctxt *authctxt) } #endif +#ifdef AUDIT_EVENTS + PRIVSEP(audit_event(CONNECTION_CLOSE)); +#endif + /* remove agent socket */ auth_sock_cleanup_proc(authctxt->pw); diff --git a/sshd.c b/sshd.c index 23d6962c..e61870ea 100644 --- a/sshd.c +++ b/sshd.c @@ -1628,6 +1628,9 @@ main(int ac, char **av) remote_port = get_remote_port(); remote_ip = get_remote_ipaddr(); +#ifdef AUDIT_EVENTS + audit_connection_from(remote_ip, remote_port); +#endif #ifdef LIBWRAP /* Check whether logins are denied from this host. */ if (packet_connection_is_on_socket()) { @@ -1697,6 +1700,10 @@ main(int ac, char **av) } authenticated: +#ifdef AUDIT_EVENTS + audit_event(AUTH_SUCCESS); +#endif + /* * In privilege separation, we fork another child and prepare * file descriptor passing. @@ -2010,5 +2017,10 @@ cleanup_exit(int i) { if (the_authctxt) do_cleanup(the_authctxt); +#ifdef AUDIT_EVENTS + /* done after do_cleanup so it can cancel the PAM auth 'thread' */ + if (!use_privsep || mm_is_monitor()) + audit_event(CONNECTION_ABANDON); +#endif _exit(i); } -- 2.45.1