diff -up openssh-5.8p1/misc.c.mls openssh-5.8p1/misc.c --- openssh-5.8p1/misc.c.mls 2011-01-13 02:21:36.000000000 +0100 +++ openssh-5.8p1/misc.c 2011-02-12 15:05:06.000000000 +0100 @@ -427,6 +427,7 @@ char * colon(char *cp) { int flag = 0; + int start = 1; if (*cp == ':') /* Leading colon is part of file name. */ return NULL; @@ -442,6 +443,13 @@ colon(char *cp) return (cp); if (*cp == '/') return NULL; + if (start) { + /* Slash on beginning or after dots only denotes file name. */ + if (*cp == '/') + return (0); + if (*cp != '.') + start = 0; + } } return NULL; } diff -up openssh-5.8p1/openbsd-compat/port-linux.c.mls openssh-5.8p1/openbsd-compat/port-linux.c --- openssh-5.8p1/openbsd-compat/port-linux.c.mls 2011-02-12 15:05:06.000000000 +0100 +++ openssh-5.8p1/openbsd-compat/port-linux.c 2011-02-12 15:09:23.000000000 +0100 @@ -40,13 +40,164 @@ #ifdef WITH_SELINUX #include #include +#include #include +#include +#include + +#ifdef HAVE_LINUX_AUDIT +#include +#include +#endif extern ServerOptions options; extern Authctxt *the_authctxt; extern int inetd_flag; extern int rexeced_flag; +/* Send audit message */ +static int +send_audit_message(int success, security_context_t default_context, + security_context_t selected_context) +{ + int rc=0; +#ifdef HAVE_LINUX_AUDIT + char *msg = NULL; + int audit_fd = audit_open(); + security_context_t default_raw=NULL; + security_context_t selected_raw=NULL; + rc = -1; + if (audit_fd < 0) { + if (errno == EINVAL || errno == EPROTONOSUPPORT || + errno == EAFNOSUPPORT) + return 0; /* No audit support in kernel */ + error("Error connecting to audit system."); + return rc; + } + if (selinux_trans_to_raw_context(default_context, &default_raw) < 0) { + error("Error translating default context."); + default_raw = NULL; + } + if (selinux_trans_to_raw_context(selected_context, &selected_raw) < 0) { + error("Error translating selected context."); + selected_raw = NULL; + } + if (asprintf(&msg, "sshd: default-context=%s selected-context=%s", + default_raw ? default_raw : (default_context ? default_context: "?"), + selected_context ? selected_raw : (selected_context ? selected_context :"?")) < 0) { + error("Error allocating memory."); + goto out; + } + if (audit_log_user_message(audit_fd, AUDIT_USER_ROLE_CHANGE, + msg, NULL, NULL, NULL, success) <= 0) { + error("Error sending audit message."); + goto out; + } + rc = 0; + out: + free(msg); + freecon(default_raw); + freecon(selected_raw); + close(audit_fd); +#endif + return rc; +} + +static int +mls_range_allowed(security_context_t src, security_context_t dst) +{ + struct av_decision avd; + int retval; + unsigned int bit = CONTEXT__CONTAINS; + + debug("%s: src:%s dst:%s", __func__, src, dst); + retval = security_compute_av(src, dst, SECCLASS_CONTEXT, bit, &avd); + if (retval || ((bit & avd.allowed) != bit)) + return 0; + + return 1; +} + +static int +get_user_context(const char *sename, const char *role, const char *lvl, + security_context_t *sc) { +#ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL + if (lvl == NULL || lvl[0] == '\0' || get_default_context_with_level(sename, lvl, NULL, sc) != 0) { + /* User may have requested a level completely outside of his + allowed range. We get a context just for auditing as the + range check below will certainly fail for default context. */ +#endif + if (get_default_context(sename, NULL, sc) != 0) { + *sc = NULL; + return -1; + } +#ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL + } +#endif + if (role != NULL && role[0]) { + context_t con; + char *type=NULL; + if (get_default_type(role, &type) != 0) { + error("get_default_type: failed to get default type for '%s'", + role); + goto out; + } + con = context_new(*sc); + if (!con) { + goto out; + } + context_role_set(con, role); + context_type_set(con, type); + freecon(*sc); + *sc = strdup(context_str(con)); + context_free(con); + if (!*sc) + return -1; + } +#ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL + if (lvl != NULL && lvl[0]) { + /* verify that the requested range is obtained */ + context_t con; + security_context_t obtained_raw; + security_context_t requested_raw; + con = context_new(*sc); + if (!con) { + goto out; + } + context_range_set(con, lvl); + if (selinux_trans_to_raw_context(*sc, &obtained_raw) < 0) { + context_free(con); + goto out; + } + if (selinux_trans_to_raw_context(context_str(con), &requested_raw) < 0) { + freecon(obtained_raw); + context_free(con); + goto out; + } + + debug("get_user_context: obtained context '%s' requested context '%s'", + obtained_raw, requested_raw); + if (strcmp(obtained_raw, requested_raw)) { + /* set the context to the real requested one but fail */ + freecon(requested_raw); + freecon(obtained_raw); + freecon(*sc); + *sc = strdup(context_str(con)); + context_free(con); + return -1; + } + freecon(requested_raw); + freecon(obtained_raw); + context_free(con); + } +#endif + return 0; + out: + freecon(*sc); + *sc = NULL; + return -1; +} + static void ssh_selinux_get_role_level(char **role, const char **level) { @@ -65,14 +216,15 @@ ssh_selinux_get_role_level(char **role, } /* Return the default security context for the given username */ -static security_context_t -ssh_selinux_getctxbyname(char *pwname) +static int +ssh_selinux_getctxbyname(char *pwname, + security_context_t *default_sc, security_context_t *user_sc) { - security_context_t sc = NULL; char *sename, *lvl; char *role; const char *reqlvl; int r = 0; + context_t con = NULL; ssh_selinux_get_role_level(&role, &reqlvl); #ifdef HAVE_GETSEUSERBYNAME @@ -82,38 +235,63 @@ ssh_selinux_getctxbyname(char *pwname) } #else sename = pwname; - lvl = NULL; + lvl = ""; #endif if (r == 0) { #ifdef HAVE_GET_DEFAULT_CONTEXT_WITH_LEVEL - 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); + r = get_default_context_with_level(sename, lvl, NULL, default_sc); #else - if (role != NULL && role[0]) - r = get_default_context_with_role(sename, role, NULL, &sc); - else - r = get_default_context(sename, NULL, &sc); + r = get_default_context(sename, NULL, default_sc); #endif } - if (r != 0) { - switch (security_getenforce()) { - case -1: - fatal("%s: ssh_selinux_getctxbyname: " - "security_getenforce() failed", __func__); - case 0: - error("%s: Failed to get default SELinux security " - "context for %s", __func__, pwname); - break; - default: - fatal("%s: Failed to get default SELinux security " - "context for %s (in enforcing mode)", - __func__, pwname); + if (r == 0) { + /* If launched from xinetd, we must use current level */ + if (inetd_flag && !rexeced_flag) { + security_context_t sshdsc=NULL; + + if (getcon_raw(&sshdsc) < 0) + fatal("failed to allocate security context"); + + if ((con=context_new(sshdsc)) == NULL) + fatal("failed to allocate selinux context"); + reqlvl = context_range_get(con); + freecon(sshdsc); + if (reqlvl !=NULL && lvl != NULL && strcmp(reqlvl, lvl) == 0) + /* we actually don't change level */ + reqlvl = ""; + + debug("%s: current connection level '%s'", __func__, reqlvl); + } + + if ((reqlvl != NULL && reqlvl[0]) || (role != NULL && role[0])) { + r = get_user_context(sename, role, reqlvl, user_sc); + + if (r == 0 && reqlvl != NULL && reqlvl[0]) { + security_context_t default_level_sc = *default_sc; + if (role != NULL && role[0]) { + if (get_user_context(sename, role, lvl, &default_level_sc) < 0) + default_level_sc = *default_sc; + } + /* verify that the requested range is contained in the user range */ + if (mls_range_allowed(default_level_sc, *user_sc)) { + logit("permit MLS level %s (user range %s)", reqlvl, lvl); + } else { + r = -1; + error("deny MLS level %s (user range %s)", reqlvl, lvl); + } + if (default_level_sc != *default_sc) + freecon(default_level_sc); + } + } else { + *user_sc = *default_sc; } } + if (r != 0) { + error("%s: Failed to get default SELinux security " + "context for %s", __func__, pwname); + } #ifdef HAVE_GETSEUSERBYNAME if (sename != NULL) @@ -121,8 +299,12 @@ ssh_selinux_getctxbyname(char *pwname) if (lvl != NULL) xfree(lvl); #endif - - return (sc); + if (role != NULL) + xfree(role); + if (con) + context_free(con); + + return (r); } /* Setup environment variables for pam_selinux */ @@ -160,6 +342,8 @@ void ssh_selinux_setup_exec_context(char *pwname) { security_context_t user_ctx = NULL; + int r = 0; + security_context_t default_ctx = NULL; if (!ssh_selinux_enabled()) return; @@ -184,22 +368,45 @@ ssh_selinux_setup_exec_context(char *pwn debug3("%s: setting execution context", __func__); - user_ctx = ssh_selinux_getctxbyname(pwname); - if (setexeccon(user_ctx) != 0) { + r = ssh_selinux_getctxbyname(pwname, &default_ctx, &user_ctx); + if (r >= 0) { + r = setexeccon(user_ctx); + if (r < 0) { + error("%s: Failed to set SELinux execution context %s for %s", + __func__, user_ctx, pwname); + } +#ifdef HAVE_SETKEYCREATECON + else if (setkeycreatecon(user_ctx) < 0) { + error("%s: Failed to set SELinux keyring creation context %s for %s", + __func__, user_ctx, pwname); + } +#endif + } + if (user_ctx == NULL) { + user_ctx = default_ctx; + } + if (r < 0 || user_ctx != default_ctx) { + /* audit just the case when user changed a role or there was + a failure */ + send_audit_message(r >= 0, default_ctx, user_ctx); + } + if (r < 0) { switch (security_getenforce()) { case -1: fatal("%s: security_getenforce() failed", __func__); case 0: - error("%s: Failed to set SELinux execution " - "context for %s", __func__, pwname); + error("%s: SELinux failure. Continuing in permissive mode.", + __func__); break; default: - fatal("%s: Failed to set SELinux execution context " - "for %s (in enforcing mode)", __func__, pwname); + fatal("%s: SELinux failure. Aborting connection.", + __func__); } } - if (user_ctx != NULL) + if (user_ctx != NULL && user_ctx != default_ctx) freecon(user_ctx); + if (default_ctx != NULL) + freecon(default_ctx); debug3("%s: done", __func__); } @@ -217,7 +424,10 @@ ssh_selinux_setup_pty(char *pwname, cons debug3("%s: setting TTY context on %s", __func__, tty); - user_ctx = ssh_selinux_getctxbyname(pwname); + if (getexeccon(&user_ctx) < 0) { + error("%s: getexeccon: %s", __func__, strerror(errno)); + goto out; + } /* XXX: should these calls fatal() upon failure in enforcing mode? */ diff -up openssh-5.8p1/sshd.c.mls openssh-5.8p1/sshd.c --- openssh-5.8p1/sshd.c.mls 2011-02-12 15:05:05.000000000 +0100 +++ openssh-5.8p1/sshd.c 2011-02-12 15:05:06.000000000 +0100 @@ -2011,6 +2011,9 @@ main(int ac, char **av) restore_uid(); } #endif +#ifdef WITH_SELINUX + ssh_selinux_setup_exec_context(authctxt->pw->pw_name); +#endif #ifdef USE_PAM if (options.use_pam) { do_pam_setcred(1);