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 <srivasta@debian.org>
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;
 
@@ -291,12 +291,30 @@
 	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
 mm_auth_password(Authctxt *authctxt, char *password)
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
@@ -29,6 +29,12 @@
 #include <string.h>
 #include <stdio.h>
 
+#ifdef WITH_SELINUX
+#include "key.h"
+#include "hostfile.h"
+#include "auth.h"
+#endif
+
 #include "log.h"
 #include "xmalloc.h"
 #include "port-linux.h"
@@ -38,6 +44,8 @@
 #include <selinux/flask.h>
 #include <selinux/get_context_list.h>
 
+extern Authctxt *the_authctxt;
+
 /* Wrapper around is_selinux_enabled() to log its return value once only */
 int
 ssh_selinux_enabled(void)
@@ -56,8 +64,8 @@
 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
@@ -67,11 +75,20 @@
 	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) {
