Description: Handle SELinux authorisation roles Rejected upstream due to discomfort with magic usernames; a better approach will need an SSH protocol change. In the meantime, this came from Debian's SELinux maintainer, so we'll keep it until we have something better. Author: Manoj Srivastava Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1641 Bug-Debian: http://bugs.debian.org/394795 Last-Update: 2010-02-27 Index: b/auth.h =================================================================== --- a/auth.h +++ b/auth.h @@ -59,6 +59,7 @@ char *service; struct passwd *pw; /* set if 'valid' */ char *style; + char *role; void *kbdintctxt; void *jpake_ctx; #ifdef BSD_AUTH Index: b/auth1.c =================================================================== --- a/auth1.c +++ b/auth1.c @@ -383,7 +383,7 @@ do_authentication(Authctxt *authctxt) { u_int ulen; - char *user, *style = NULL; + char *user, *style = NULL, *role = NULL; /* Get the name of the user that we wish to log in as. */ packet_read_expect(SSH_CMSG_USER); @@ -392,11 +392,17 @@ user = packet_get_string(&ulen); packet_check_eom(); + if ((role = strchr(user, '/')) != NULL) + *role++ = '\0'; + if ((style = strchr(user, ':')) != NULL) *style++ = '\0'; + else if (role && (style = strchr(role, ':')) != NULL) + *style++ = '\0'; authctxt->user = user; authctxt->style = style; + authctxt->role = role; /* Verify that the user is a valid user. */ if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL) Index: b/auth2.c =================================================================== --- a/auth2.c +++ b/auth2.c @@ -217,7 +217,7 @@ { Authctxt *authctxt = ctxt; Authmethod *m = NULL; - char *user, *service, *method, *style = NULL; + char *user, *service, *method, *style = NULL, *role = NULL; int authenticated = 0; if (authctxt == NULL) @@ -229,8 +229,13 @@ debug("userauth-request for user %s service %s method %s", user, service, method); debug("attempt %d failures %d", authctxt->attempt, authctxt->failures); + if ((role = strchr(user, '/')) != NULL) + *role++ = 0; + if ((style = strchr(user, ':')) != NULL) *style++ = 0; + else if (role && (style = strchr(role, ':')) != NULL) + *style++ = '\0'; if (authctxt->attempt++ == 0) { /* setup auth context */ @@ -254,8 +259,9 @@ use_privsep ? " [net]" : ""); authctxt->service = xstrdup(service); authctxt->style = style ? xstrdup(style) : NULL; + authctxt->role = role ? xstrdup(role) : NULL; if (use_privsep) - mm_inform_authserv(service, style); + mm_inform_authserv(service, style, role); userauth_banner(); } else if (strcmp(user, authctxt->user) != 0 || strcmp(service, authctxt->service) != 0) { Index: b/monitor.c =================================================================== --- a/monitor.c +++ b/monitor.c @@ -137,6 +137,7 @@ int mm_answer_pwnamallow(int, Buffer *); int mm_answer_auth2_read_banner(int, Buffer *); int mm_answer_authserv(int, Buffer *); +int mm_answer_authrole(int, Buffer *); int mm_answer_authpassword(int, Buffer *); int mm_answer_bsdauthquery(int, Buffer *); int mm_answer_bsdauthrespond(int, Buffer *); @@ -215,6 +216,7 @@ {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_AUTHROLE, MON_ONCE, mm_answer_authrole}, {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner}, {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword}, #ifdef USE_PAM @@ -699,6 +701,7 @@ else { /* Allow service/style information on the auth context */ monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1); + monitor_permit(mon_dispatch, MONITOR_REQ_AUTHROLE, 1); monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1); } @@ -732,14 +735,37 @@ authctxt->service = buffer_get_string(m, NULL); authctxt->style = buffer_get_string(m, NULL); - debug3("%s: service=%s, style=%s", - __func__, authctxt->service, authctxt->style); + authctxt->role = buffer_get_string(m, NULL); + debug3("%s: service=%s, style=%s, role=%s", + __func__, authctxt->service, authctxt->style, authctxt->role); if (strlen(authctxt->style) == 0) { xfree(authctxt->style); authctxt->style = NULL; } + if (strlen(authctxt->role) == 0) { + xfree(authctxt->role); + authctxt->role = NULL; + } + + return (0); +} + +int +mm_answer_authrole(int sock, Buffer *m) +{ + monitor_permit_authentications(1); + + authctxt->role = buffer_get_string(m, NULL); + debug3("%s: role=%s", + __func__, authctxt->role); + + if (strlen(authctxt->role) == 0) { + xfree(authctxt->role); + authctxt->role = NULL; + } + return (0); } Index: b/monitor.h =================================================================== --- a/monitor.h +++ b/monitor.h @@ -30,7 +30,7 @@ enum monitor_reqtype { MONITOR_REQ_MODULI, MONITOR_ANS_MODULI, - MONITOR_REQ_FREE, MONITOR_REQ_AUTHSERV, + MONITOR_REQ_FREE, MONITOR_REQ_AUTHSERV, MONITOR_REQ_AUTHROLE, MONITOR_REQ_SIGN, MONITOR_ANS_SIGN, MONITOR_REQ_PWNAM, MONITOR_ANS_PWNAM, MONITOR_REQ_AUTH2_READ_BANNER, MONITOR_ANS_AUTH2_READ_BANNER, Index: b/monitor_wrap.c =================================================================== --- a/monitor_wrap.c +++ b/monitor_wrap.c @@ -279,10 +279,10 @@ return (banner); } -/* Inform the privileged process about service and style */ +/* Inform the privileged process about service, style, and role */ void -mm_inform_authserv(char *service, char *style) +mm_inform_authserv(char *service, char *style, char *role) { Buffer m; @@ -291,11 +291,29 @@ buffer_init(&m); buffer_put_cstring(&m, service); buffer_put_cstring(&m, style ? style : ""); + buffer_put_cstring(&m, role ? role : ""); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m); buffer_free(&m); } + +/* Inform the privileged process about role */ + +void +mm_inform_authrole(char *role) +{ + Buffer m; + + debug3("%s entering", __func__); + + buffer_init(&m); + buffer_put_cstring(&m, role ? role : ""); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHROLE, &m); + + buffer_free(&m); +} /* Do the password authentication */ int Index: b/monitor_wrap.h =================================================================== --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -40,7 +40,8 @@ int mm_is_monitor(void); DH *mm_choose_dh(int, int, int); int mm_key_sign(Key *, u_char **, u_int *, u_char *, u_int); -void mm_inform_authserv(char *, char *); +void mm_inform_authserv(char *, char *, char *); +void mm_inform_authrole(char *); struct passwd *mm_getpwnamallow(const char *); char *mm_auth2_read_banner(void); int mm_auth_password(struct Authctxt *, char *); Index: b/openbsd-compat/port-linux.c =================================================================== --- a/openbsd-compat/port-linux.c +++ b/openbsd-compat/port-linux.c @@ -28,6 +28,12 @@ #include #ifdef WITH_SELINUX +#include "key.h" +#include "hostfile.h" +#include "auth.h" +#ifdef HAVE_GETSEUSERBYNAME +#include "xmalloc.h" +#endif #include "log.h" #include "port-linux.h" @@ -35,6 +41,8 @@ #include #include +extern Authctxt *the_authctxt; + /* Wrapper around is_selinux_enabled() to log its return value once only */ int ssh_selinux_enabled(void) @@ -53,8 +61,8 @@ static security_context_t ssh_selinux_getctxbyname(char *pwname) { - security_context_t sc; - char *sename = NULL, *lvl = NULL; + security_context_t sc = NULL; + char *sename = NULL, *role = NULL, *lvl = NULL; int r; #ifdef HAVE_GETSEUSERBYNAME @@ -64,11 +72,20 @@ sename = pwname; lvl = NULL; #endif + if (the_authctxt) + role = the_authctxt->role; #ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL - r = get_default_context_with_level(sename, lvl, NULL, &sc); + if (role != NULL && role[0]) + r = get_default_context_with_rolelevel(sename, role, lvl, NULL, + &sc); + else + r = get_default_context_with_level(sename, lvl, NULL, &sc); #else - r = get_default_context(sename, NULL, &sc); + if (role != NULL && role[0]) + r = get_default_context_with_role(sename, role, NULL, &sc); + else + r = get_default_context(sename, NULL, &sc); #endif if (r != 0) {