1 files changed, 111 insertions, 1 deletions

diff --git a/sshd.c b/sshd.c
index 51a1aaf6e..45e50fac3 100644
--- a/sshd.c
+++ b/sshd.c
@@ -122,6 +122,10 @@
 #include "version.h"
 #include "ssherr.h"
 
+#ifdef USE_SECURITY_SESSION_API
+#include <Security/AuthSession.h>
+#endif
+
 /* Re-exec fds */
 #define REEXEC_DEVCRYPTO_RESERVED_FD    (STDERR_FILENO + 1)
 #define REEXEC_STARTUP_PIPE_FD          (STDERR_FILENO + 2)
@@ -529,7 +533,7 @@ privsep_preauth_child(void)
 
 #ifdef GSSAPI
         /* Cache supported mechanism OIDs for later use */
-        if (options.gss_authentication)
+        if (options.gss_authentication || options.gss_keyex)
                 ssh_gssapi_prepare_supported_oids();
 #endif
 
@@ -1708,10 +1712,13 @@ main(int ac, char **av)
                     key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp);
                 free(fp);
         }
+#ifndef GSSAPI
+        /* The GSSAPI key exchange can run without a host key */
         if (!sensitive_data.have_ssh2_key) {
                 logit("sshd: no hostkeys available -- exiting.");
                 exit(1);
         }
+#endif
 
         /*
          * Load certificates. They are stored in an array at identical
@@ -1987,6 +1994,60 @@ main(int ac, char **av)
             remote_ip, remote_port, laddr,  ssh_local_port(ssh));
         free(laddr);
 
+#ifdef USE_SECURITY_SESSION_API
+        /*
+         * Create a new security session for use by the new user login if
+         * the current session is the root session or we are not launched
+         * by inetd (eg: debugging mode or server mode).  We do not
+         * necessarily need to create a session if we are launched from
+         * inetd because Panther xinetd will create a session for us.
+         *
+         * The only case where this logic will fail is if there is an
+         * inetd running in a non-root session which is not creating
+         * new sessions for us.  Then all the users will end up in the
+         * same session (bad).
+         *
+         * When the client exits, the session will be destroyed for us
+         * automatically.
+         *
+         * We must create the session before any credentials are stored
+         * (including AFS pags, which happens a few lines below).
+         */
+        {
+                OSStatus err = 0;
+                SecuritySessionId sid = 0;
+                SessionAttributeBits sattrs = 0;
+
+                err = SessionGetInfo(callerSecuritySession, &sid, &sattrs);
+                if (err)
+                        error("SessionGetInfo() failed with error %.8X",
+                            (unsigned) err);
+                else
+                        debug("Current Session ID is %.8X / Session Attributes are %.8X",
+                            (unsigned) sid, (unsigned) sattrs);
+
+                if (inetd_flag && !(sattrs & sessionIsRoot))
+                        debug("Running in inetd mode in a non-root session... "
+                            "assuming inetd created the session for us.");
+                else {
+                        debug("Creating new security session...");
+                        err = SessionCreate(0, sessionHasTTY | sessionIsRemote);
+                        if (err)
+                                error("SessionCreate() failed with error %.8X",
+                                    (unsigned) err);
+
+                        err = SessionGetInfo(callerSecuritySession, &sid, 
+                            &sattrs);
+                        if (err)
+                                error("SessionGetInfo() failed with error %.8X",
+                                    (unsigned) err);
+                        else
+                                debug("New Session ID is %.8X / Session Attributes are %.8X",
+                                    (unsigned) sid, (unsigned) sattrs);
+                }
+        }
+#endif
+
         /*
          * We don't want to listen forever unless the other side
          * successfully authenticates itself.  So we set up an alarm which is
@@ -2170,6 +2231,48 @@ do_ssh2_kex(void)
         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
             list_hostkey_types());
 
+#ifdef GSSAPI
+        {
+        char *orig;
+        char *gss = NULL;
+        char *newstr = NULL;
+        orig = myproposal[PROPOSAL_KEX_ALGS];
+
+        /* 
+         * If we don't have a host key, then there's no point advertising
+         * the other key exchange algorithms
+         */
+
+        if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0)
+                orig = NULL;
+
+        if (options.gss_keyex)
+                gss = ssh_gssapi_server_mechanisms();
+        else
+                gss = NULL;
+
+        if (gss && orig)
+                xasprintf(&newstr, "%s,%s", gss, orig);
+        else if (gss)
+                newstr = gss;
+        else if (orig)
+                newstr = orig;
+
+        /* 
+         * If we've got GSSAPI mechanisms, then we've got the 'null' host
+         * key alg, but we can't tell people about it unless its the only
+         * host key algorithm we support
+         */
+        if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0)
+                myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null";
+
+        if (newstr)
+                myproposal[PROPOSAL_KEX_ALGS] = newstr;
+        else
+                fatal("No supported key exchange algorithms");
+        }
+#endif
+
         /* start key exchange */
         if ((r = kex_setup(active_state, myproposal)) != 0)
                 fatal("kex_setup: %s", ssh_err(r));
@@ -2187,6 +2290,13 @@ do_ssh2_kex(void)
 # endif
 #endif
         kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+#ifdef GSSAPI
+        if (options.gss_keyex) {
+                kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
+                kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
+                kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
+        }
+#endif
         kex->server = 1;
         kex->client_version_string=client_version_string;
         kex->server_version_string=server_version_string;