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-rw-r--r--debian/patches/gssapi.patch3142
1 files changed, 3142 insertions, 0 deletions
diff --git a/debian/patches/gssapi.patch b/debian/patches/gssapi.patch
new file mode 100644
index 000000000..d8439bf03
--- /dev/null
+++ b/debian/patches/gssapi.patch
@@ -0,0 +1,3142 @@
1From 9dfcd1a0e691c1cad34b168e27b3ed31ab6986cd Mon Sep 17 00:00:00 2001
2From: Simon Wilkinson <simon@sxw.org.uk>
3Date: Sun, 9 Feb 2014 16:09:48 +0000
4Subject: GSSAPI key exchange support
5
6This patch has been rejected upstream: "None of the OpenSSH developers are
7in favour of adding this, and this situation has not changed for several
8years. This is not a slight on Simon's patch, which is of fine quality, but
9just that a) we don't trust GSSAPI implementations that much and b) we don't
10like adding new KEX since they are pre-auth attack surface. This one is
11particularly scary, since it requires hooks out to typically root-owned
12system resources."
13
14However, quite a lot of people rely on this in Debian, and it's better to
15have it merged into the main openssh package rather than having separate
16-krb5 packages (as we used to have). It seems to have a generally good
17security history.
18
19Bug: https://bugzilla.mindrot.org/show_bug.cgi?id=1242
20Last-Updated: 2014-03-19
21
22Patch-Name: gssapi.patch
23---
24 ChangeLog.gssapi | 113 +++++++++++++++++++
25 Makefile.in | 3 +-
26 auth-krb5.c | 17 ++-
27 auth2-gss.c | 48 +++++++-
28 auth2.c | 2 +
29 clientloop.c | 13 +++
30 config.h.in | 6 +
31 configure | 57 ++++++++++
32 configure.ac | 24 ++++
33 gss-genr.c | 275 ++++++++++++++++++++++++++++++++++++++++++++-
34 gss-serv-krb5.c | 85 ++++++++++++--
35 gss-serv.c | 221 +++++++++++++++++++++++++++++++-----
36 kex.c | 16 +++
37 kex.h | 14 +++
38 kexgssc.c | 332 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
39 kexgsss.c | 289 ++++++++++++++++++++++++++++++++++++++++++++++++
40 key.c | 3 +-
41 key.h | 1 +
42 monitor.c | 108 +++++++++++++++++-
43 monitor.h | 3 +
44 monitor_wrap.c | 47 +++++++-
45 monitor_wrap.h | 4 +-
46 readconf.c | 42 +++++++
47 readconf.h | 5 +
48 servconf.c | 38 ++++++-
49 servconf.h | 3 +
50 ssh-gss.h | 41 ++++++-
51 ssh_config | 2 +
52 ssh_config.5 | 34 +++++-
53 sshconnect2.c | 124 ++++++++++++++++++++-
54 sshd.c | 110 ++++++++++++++++++
55 sshd_config | 2 +
56 sshd_config.5 | 28 +++++
57 33 files changed, 2051 insertions(+), 59 deletions(-)
58 create mode 100644 ChangeLog.gssapi
59 create mode 100644 kexgssc.c
60 create mode 100644 kexgsss.c
61
62diff --git a/ChangeLog.gssapi b/ChangeLog.gssapi
63new file mode 100644
64index 0000000..f117a33
65--- /dev/null
66+++ b/ChangeLog.gssapi
67@@ -0,0 +1,113 @@
68+20110101
69+ - Finally update for OpenSSH 5.6p1
70+ - Add GSSAPIServerIdentity option from Jim Basney
71+
72+20100308
73+ - [ Makefile.in, key.c, key.h ]
74+ Updates for OpenSSH 5.4p1
75+ - [ servconf.c ]
76+ Include GSSAPI options in the sshd -T configuration dump, and flag
77+ some older configuration options as being unsupported. Thanks to Colin
78+ Watson.
79+ -
80+
81+20100124
82+ - [ sshconnect2.c ]
83+ Adapt to deal with additional element in Authmethod structure. Thanks to
84+ Colin Watson
85+
86+20090615
87+ - [ gss-genr.c gss-serv.c kexgssc.c kexgsss.c monitor.c sshconnect2.c
88+ sshd.c ]
89+ Fix issues identified by Greg Hudson following a code review
90+ Check return value of gss_indicate_mechs
91+ Protect GSSAPI calls in monitor, so they can only be used if enabled
92+ Check return values of bignum functions in key exchange
93+ Use BN_clear_free to clear other side's DH value
94+ Make ssh_gssapi_id_kex more robust
95+ Only configure kex table pointers if GSSAPI is enabled
96+ Don't leak mechanism list, or gss mechanism list
97+ Cast data.length before printing
98+ If serverkey isn't provided, use an empty string, rather than NULL
99+
100+20090201
101+ - [ gss-genr.c gss-serv.c kex.h kexgssc.c readconf.c readconf.h ssh-gss.h
102+ ssh_config.5 sshconnet2.c ]
103+ Add support for the GSSAPIClientIdentity option, which allows the user
104+ to specify which GSSAPI identity to use to contact a given server
105+
106+20080404
107+ - [ gss-serv.c ]
108+ Add code to actually implement GSSAPIStrictAcceptCheck, which had somehow
109+ been omitted from a previous version of this patch. Reported by Borislav
110+ Stoichkov
111+
112+20070317
113+ - [ gss-serv-krb5.c ]
114+ Remove C99ism, where new_ccname was being declared in the middle of a
115+ function
116+
117+20061220
118+ - [ servconf.c ]
119+ Make default for GSSAPIStrictAcceptorCheck be Yes, to match previous, and
120+ documented, behaviour. Reported by Dan Watson.
121+
122+20060910
123+ - [ gss-genr.c kexgssc.c kexgsss.c kex.h monitor.c sshconnect2.c sshd.c
124+ ssh-gss.h ]
125+ add support for gss-group14-sha1 key exchange mechanisms
126+ - [ gss-serv.c servconf.c servconf.h sshd_config sshd_config.5 ]
127+ Add GSSAPIStrictAcceptorCheck option to allow the disabling of
128+ acceptor principal checking on multi-homed machines.
129+ <Bugzilla #928>
130+ - [ sshd_config ssh_config ]
131+ Add settings for GSSAPIKeyExchange and GSSAPITrustDNS to the sample
132+ configuration files
133+ - [ kexgss.c kegsss.c sshconnect2.c sshd.c ]
134+ Code cleanup. Replace strlen/xmalloc/snprintf sequences with xasprintf()
135+ Limit length of error messages displayed by client
136+
137+20060909
138+ - [ gss-genr.c gss-serv.c ]
139+ move ssh_gssapi_acquire_cred() and ssh_gssapi_server_ctx to be server
140+ only, where they belong
141+ <Bugzilla #1225>
142+
143+20060829
144+ - [ gss-serv-krb5.c ]
145+ Fix CCAPI credentials cache name when creating KRB5CCNAME environment
146+ variable
147+
148+20060828
149+ - [ gss-genr.c ]
150+ Avoid Heimdal context freeing problem
151+ <Fixed upstream 20060829>
152+
153+20060818
154+ - [ gss-genr.c ssh-gss.h sshconnect2.c ]
155+ Make sure that SPENGO is disabled
156+ <Bugzilla #1218 - Fixed upstream 20060818>
157+
158+20060421
159+ - [ gssgenr.c, sshconnect2.c ]
160+ a few type changes (signed versus unsigned, int versus size_t) to
161+ fix compiler errors/warnings
162+ (from jbasney AT ncsa.uiuc.edu)
163+ - [ kexgssc.c, sshconnect2.c ]
164+ fix uninitialized variable warnings
165+ (from jbasney AT ncsa.uiuc.edu)
166+ - [ gssgenr.c ]
167+ pass oid to gss_display_status (helpful when using GSSAPI mechglue)
168+ (from jbasney AT ncsa.uiuc.edu)
169+ <Bugzilla #1220 >
170+ - [ gss-serv-krb5.c ]
171+ #ifdef HAVE_GSSAPI_KRB5 should be #ifdef HAVE_GSSAPI_KRB5_H
172+ (from jbasney AT ncsa.uiuc.edu)
173+ <Fixed upstream 20060304>
174+ - [ readconf.c, readconf.h, ssh_config.5, sshconnect2.c
175+ add client-side GssapiKeyExchange option
176+ (from jbasney AT ncsa.uiuc.edu)
177+ - [ sshconnect2.c ]
178+ add support for GssapiTrustDns option for gssapi-with-mic
179+ (from jbasney AT ncsa.uiuc.edu)
180+ <gssapi-with-mic support is Bugzilla #1008>
181diff --git a/Makefile.in b/Makefile.in
182index 28a8ec4..ee1d2c3 100644
183--- a/Makefile.in
184+++ b/Makefile.in
185@@ -72,6 +72,7 @@ LIBSSH_OBJS=authfd.o authfile.o bufaux.o bufbn.o buffer.o \
186 atomicio.o key.o dispatch.o kex.o mac.o uidswap.o uuencode.o misc.o \
187 monitor_fdpass.o rijndael.o ssh-dss.o ssh-ecdsa.o ssh-rsa.o dh.o \
188 kexdh.o kexgex.o kexdhc.o kexgexc.o bufec.o kexecdh.o kexecdhc.o \
189+ kexgssc.o \
190 msg.o progressmeter.o dns.o entropy.o gss-genr.o umac.o umac128.o \
191 ssh-pkcs11.o krl.o smult_curve25519_ref.o \
192 kexc25519.o kexc25519c.o poly1305.o chacha.o cipher-chachapoly.o \
193@@ -91,7 +92,7 @@ SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o auth-rsa.o auth-rh-rsa.o \
194 auth2-none.o auth2-passwd.o auth2-pubkey.o \
195 monitor_mm.o monitor.o monitor_wrap.o kexdhs.o kexgexs.o kexecdhs.o \
196 kexc25519s.o auth-krb5.o \
197- auth2-gss.o gss-serv.o gss-serv-krb5.o \
198+ auth2-gss.o gss-serv.o gss-serv-krb5.o kexgsss.o \
199 loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o \
200 sftp-server.o sftp-common.o \
201 roaming_common.o roaming_serv.o \
202diff --git a/auth-krb5.c b/auth-krb5.c
203index 6c62bdf..69a1a53 100644
204--- a/auth-krb5.c
205+++ b/auth-krb5.c
206@@ -182,8 +182,13 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
207
208 len = strlen(authctxt->krb5_ticket_file) + 6;
209 authctxt->krb5_ccname = xmalloc(len);
210+#ifdef USE_CCAPI
211+ snprintf(authctxt->krb5_ccname, len, "API:%s",
212+ authctxt->krb5_ticket_file);
213+#else
214 snprintf(authctxt->krb5_ccname, len, "FILE:%s",
215 authctxt->krb5_ticket_file);
216+#endif
217
218 #ifdef USE_PAM
219 if (options.use_pam)
220@@ -240,15 +245,22 @@ krb5_cleanup_proc(Authctxt *authctxt)
221 #ifndef HEIMDAL
222 krb5_error_code
223 ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
224- int tmpfd, ret, oerrno;
225+ int ret, oerrno;
226 char ccname[40];
227 mode_t old_umask;
228+#ifdef USE_CCAPI
229+ char cctemplate[] = "API:krb5cc_%d";
230+#else
231+ char cctemplate[] = "FILE:/tmp/krb5cc_%d_XXXXXXXXXX";
232+ int tmpfd;
233+#endif
234
235 ret = snprintf(ccname, sizeof(ccname),
236- "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
237+ cctemplate, geteuid());
238 if (ret < 0 || (size_t)ret >= sizeof(ccname))
239 return ENOMEM;
240
241+#ifndef USE_CCAPI
242 old_umask = umask(0177);
243 tmpfd = mkstemp(ccname + strlen("FILE:"));
244 oerrno = errno;
245@@ -265,6 +277,7 @@ ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
246 return oerrno;
247 }
248 close(tmpfd);
249+#endif
250
251 return (krb5_cc_resolve(ctx, ccname, ccache));
252 }
253diff --git a/auth2-gss.c b/auth2-gss.c
254index c28a705..3ff2d72 100644
255--- a/auth2-gss.c
256+++ b/auth2-gss.c
257@@ -1,7 +1,7 @@
258 /* $OpenBSD: auth2-gss.c,v 1.21 2014/02/26 20:28:44 djm Exp $ */
259
260 /*
261- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
262+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
263 *
264 * Redistribution and use in source and binary forms, with or without
265 * modification, are permitted provided that the following conditions
266@@ -52,6 +52,40 @@ static void input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
267 static void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
268 static void input_gssapi_errtok(int, u_int32_t, void *);
269
270+/*
271+ * The 'gssapi_keyex' userauth mechanism.
272+ */
273+static int
274+userauth_gsskeyex(Authctxt *authctxt)
275+{
276+ int authenticated = 0;
277+ Buffer b;
278+ gss_buffer_desc mic, gssbuf;
279+ u_int len;
280+
281+ mic.value = packet_get_string(&len);
282+ mic.length = len;
283+
284+ packet_check_eom();
285+
286+ ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
287+ "gssapi-keyex");
288+
289+ gssbuf.value = buffer_ptr(&b);
290+ gssbuf.length = buffer_len(&b);
291+
292+ /* gss_kex_context is NULL with privsep, so we can't check it here */
293+ if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context,
294+ &gssbuf, &mic))))
295+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
296+ authctxt->pw));
297+
298+ buffer_free(&b);
299+ free(mic.value);
300+
301+ return (authenticated);
302+}
303+
304 /*
305 * We only support those mechanisms that we know about (ie ones that we know
306 * how to check local user kuserok and the like)
307@@ -235,7 +269,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
308
309 packet_check_eom();
310
311- authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
312+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
313+ authctxt->pw));
314
315 authctxt->postponed = 0;
316 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
317@@ -270,7 +305,8 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
318 gssbuf.length = buffer_len(&b);
319
320 if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
321- authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
322+ authenticated =
323+ PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw));
324 else
325 logit("GSSAPI MIC check failed");
326
327@@ -285,6 +321,12 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
328 userauth_finish(authctxt, authenticated, "gssapi-with-mic", NULL);
329 }
330
331+Authmethod method_gsskeyex = {
332+ "gssapi-keyex",
333+ userauth_gsskeyex,
334+ &options.gss_authentication
335+};
336+
337 Authmethod method_gssapi = {
338 "gssapi-with-mic",
339 userauth_gssapi,
340diff --git a/auth2.c b/auth2.c
341index a5490c0..fbe3e1b 100644
342--- a/auth2.c
343+++ b/auth2.c
344@@ -69,6 +69,7 @@ extern Authmethod method_passwd;
345 extern Authmethod method_kbdint;
346 extern Authmethod method_hostbased;
347 #ifdef GSSAPI
348+extern Authmethod method_gsskeyex;
349 extern Authmethod method_gssapi;
350 #endif
351
352@@ -76,6 +77,7 @@ Authmethod *authmethods[] = {
353 &method_none,
354 &method_pubkey,
355 #ifdef GSSAPI
356+ &method_gsskeyex,
357 &method_gssapi,
358 #endif
359 &method_passwd,
360diff --git a/clientloop.c b/clientloop.c
361index 59ad3a2..6d8cd7d 100644
362--- a/clientloop.c
363+++ b/clientloop.c
364@@ -111,6 +111,10 @@
365 #include "msg.h"
366 #include "roaming.h"
367
368+#ifdef GSSAPI
369+#include "ssh-gss.h"
370+#endif
371+
372 /* import options */
373 extern Options options;
374
375@@ -1608,6 +1612,15 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
376 /* Do channel operations unless rekeying in progress. */
377 if (!rekeying) {
378 channel_after_select(readset, writeset);
379+
380+#ifdef GSSAPI
381+ if (options.gss_renewal_rekey &&
382+ ssh_gssapi_credentials_updated(NULL)) {
383+ debug("credentials updated - forcing rekey");
384+ need_rekeying = 1;
385+ }
386+#endif
387+
388 if (need_rekeying || packet_need_rekeying()) {
389 debug("need rekeying");
390 xxx_kex->done = 0;
391diff --git a/config.h.in b/config.h.in
392index 0401ad1..6bc422c 100644
393--- a/config.h.in
394+++ b/config.h.in
395@@ -1622,6 +1622,9 @@
396 /* Use btmp to log bad logins */
397 #undef USE_BTMP
398
399+/* platform uses an in-memory credentials cache */
400+#undef USE_CCAPI
401+
402 /* Use libedit for sftp */
403 #undef USE_LIBEDIT
404
405@@ -1637,6 +1640,9 @@
406 /* Use PIPES instead of a socketpair() */
407 #undef USE_PIPES
408
409+/* platform has the Security Authorization Session API */
410+#undef USE_SECURITY_SESSION_API
411+
412 /* Define if you have Solaris process contracts */
413 #undef USE_SOLARIS_PROCESS_CONTRACTS
414
415diff --git a/configure b/configure
416index d690393..b6b5b6d 100755
417--- a/configure
418+++ b/configure
419@@ -7170,6 +7170,63 @@ $as_echo "#define SSH_TUN_COMPAT_AF 1" >>confdefs.h
420
421 $as_echo "#define SSH_TUN_PREPEND_AF 1" >>confdefs.h
422
423+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking if we have the Security Authorization Session API" >&5
424+$as_echo_n "checking if we have the Security Authorization Session API... " >&6; }
425+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
426+/* end confdefs.h. */
427+#include <Security/AuthSession.h>
428+int
429+main ()
430+{
431+SessionCreate(0, 0);
432+ ;
433+ return 0;
434+}
435+_ACEOF
436+if ac_fn_c_try_compile "$LINENO"; then :
437+ ac_cv_use_security_session_api="yes"
438+
439+$as_echo "#define USE_SECURITY_SESSION_API 1" >>confdefs.h
440+
441+ LIBS="$LIBS -framework Security"
442+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
443+$as_echo "yes" >&6; }
444+else
445+ ac_cv_use_security_session_api="no"
446+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
447+$as_echo "no" >&6; }
448+fi
449+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
450+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking if we have an in-memory credentials cache" >&5
451+$as_echo_n "checking if we have an in-memory credentials cache... " >&6; }
452+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
453+/* end confdefs.h. */
454+#include <Kerberos/Kerberos.h>
455+int
456+main ()
457+{
458+cc_context_t c;
459+ (void) cc_initialize (&c, 0, NULL, NULL);
460+ ;
461+ return 0;
462+}
463+_ACEOF
464+if ac_fn_c_try_compile "$LINENO"; then :
465+
466+$as_echo "#define USE_CCAPI 1" >>confdefs.h
467+
468+ LIBS="$LIBS -framework Security"
469+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
470+$as_echo "yes" >&6; }
471+ if test "x$ac_cv_use_security_session_api" = "xno"; then
472+ as_fn_error $? "*** Need a security framework to use the credentials cache API ***" "$LINENO" 5
473+ fi
474+else
475+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
476+$as_echo "no" >&6; }
477+
478+fi
479+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
480
481 ac_fn_c_check_decl "$LINENO" "AU_IPv4" "ac_cv_have_decl_AU_IPv4" "$ac_includes_default"
482 if test "x$ac_cv_have_decl_AU_IPv4" = xyes; then :
483diff --git a/configure.ac b/configure.ac
484index 7c6ce08..d235fb0 100644
485--- a/configure.ac
486+++ b/configure.ac
487@@ -584,6 +584,30 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
488 [Use tunnel device compatibility to OpenBSD])
489 AC_DEFINE([SSH_TUN_PREPEND_AF], [1],
490 [Prepend the address family to IP tunnel traffic])
491+ AC_MSG_CHECKING([if we have the Security Authorization Session API])
492+ AC_TRY_COMPILE([#include <Security/AuthSession.h>],
493+ [SessionCreate(0, 0);],
494+ [ac_cv_use_security_session_api="yes"
495+ AC_DEFINE([USE_SECURITY_SESSION_API], [1],
496+ [platform has the Security Authorization Session API])
497+ LIBS="$LIBS -framework Security"
498+ AC_MSG_RESULT([yes])],
499+ [ac_cv_use_security_session_api="no"
500+ AC_MSG_RESULT([no])])
501+ AC_MSG_CHECKING([if we have an in-memory credentials cache])
502+ AC_TRY_COMPILE(
503+ [#include <Kerberos/Kerberos.h>],
504+ [cc_context_t c;
505+ (void) cc_initialize (&c, 0, NULL, NULL);],
506+ [AC_DEFINE([USE_CCAPI], [1],
507+ [platform uses an in-memory credentials cache])
508+ LIBS="$LIBS -framework Security"
509+ AC_MSG_RESULT([yes])
510+ if test "x$ac_cv_use_security_session_api" = "xno"; then
511+ AC_MSG_ERROR([*** Need a security framework to use the credentials cache API ***])
512+ fi],
513+ [AC_MSG_RESULT([no])]
514+ )
515 m4_pattern_allow([AU_IPv])
516 AC_CHECK_DECL([AU_IPv4], [],
517 AC_DEFINE([AU_IPv4], [0], [System only supports IPv4 audit records])
518diff --git a/gss-genr.c b/gss-genr.c
519index b39281b..1e569ad 100644
520--- a/gss-genr.c
521+++ b/gss-genr.c
522@@ -1,7 +1,7 @@
523 /* $OpenBSD: gss-genr.c,v 1.22 2013/11/08 00:39:15 djm Exp $ */
524
525 /*
526- * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
527+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
528 *
529 * Redistribution and use in source and binary forms, with or without
530 * modification, are permitted provided that the following conditions
531@@ -39,12 +39,167 @@
532 #include "buffer.h"
533 #include "log.h"
534 #include "ssh2.h"
535+#include "cipher.h"
536+#include "key.h"
537+#include "kex.h"
538+#include <openssl/evp.h>
539
540 #include "ssh-gss.h"
541
542 extern u_char *session_id2;
543 extern u_int session_id2_len;
544
545+typedef struct {
546+ char *encoded;
547+ gss_OID oid;
548+} ssh_gss_kex_mapping;
549+
550+/*
551+ * XXX - It would be nice to find a more elegant way of handling the
552+ * XXX passing of the key exchange context to the userauth routines
553+ */
554+
555+Gssctxt *gss_kex_context = NULL;
556+
557+static ssh_gss_kex_mapping *gss_enc2oid = NULL;
558+
559+int
560+ssh_gssapi_oid_table_ok(void) {
561+ return (gss_enc2oid != NULL);
562+}
563+
564+/*
565+ * Return a list of the gss-group1-sha1 mechanisms supported by this program
566+ *
567+ * We test mechanisms to ensure that we can use them, to avoid starting
568+ * a key exchange with a bad mechanism
569+ */
570+
571+char *
572+ssh_gssapi_client_mechanisms(const char *host, const char *client) {
573+ gss_OID_set gss_supported;
574+ OM_uint32 min_status;
575+
576+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported)))
577+ return NULL;
578+
579+ return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism,
580+ host, client));
581+}
582+
583+char *
584+ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check,
585+ const char *host, const char *client) {
586+ Buffer buf;
587+ size_t i;
588+ int oidpos, enclen;
589+ char *mechs, *encoded;
590+ u_char digest[EVP_MAX_MD_SIZE];
591+ char deroid[2];
592+ const EVP_MD *evp_md = EVP_md5();
593+ EVP_MD_CTX md;
594+
595+ if (gss_enc2oid != NULL) {
596+ for (i = 0; gss_enc2oid[i].encoded != NULL; i++)
597+ free(gss_enc2oid[i].encoded);
598+ free(gss_enc2oid);
599+ }
600+
601+ gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) *
602+ (gss_supported->count + 1));
603+
604+ buffer_init(&buf);
605+
606+ oidpos = 0;
607+ for (i = 0; i < gss_supported->count; i++) {
608+ if (gss_supported->elements[i].length < 128 &&
609+ (*check)(NULL, &(gss_supported->elements[i]), host, client)) {
610+
611+ deroid[0] = SSH_GSS_OIDTYPE;
612+ deroid[1] = gss_supported->elements[i].length;
613+
614+ EVP_DigestInit(&md, evp_md);
615+ EVP_DigestUpdate(&md, deroid, 2);
616+ EVP_DigestUpdate(&md,
617+ gss_supported->elements[i].elements,
618+ gss_supported->elements[i].length);
619+ EVP_DigestFinal(&md, digest, NULL);
620+
621+ encoded = xmalloc(EVP_MD_size(evp_md) * 2);
622+ enclen = __b64_ntop(digest, EVP_MD_size(evp_md),
623+ encoded, EVP_MD_size(evp_md) * 2);
624+
625+ if (oidpos != 0)
626+ buffer_put_char(&buf, ',');
627+
628+ buffer_append(&buf, KEX_GSS_GEX_SHA1_ID,
629+ sizeof(KEX_GSS_GEX_SHA1_ID) - 1);
630+ buffer_append(&buf, encoded, enclen);
631+ buffer_put_char(&buf, ',');
632+ buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID,
633+ sizeof(KEX_GSS_GRP1_SHA1_ID) - 1);
634+ buffer_append(&buf, encoded, enclen);
635+ buffer_put_char(&buf, ',');
636+ buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID,
637+ sizeof(KEX_GSS_GRP14_SHA1_ID) - 1);
638+ buffer_append(&buf, encoded, enclen);
639+
640+ gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]);
641+ gss_enc2oid[oidpos].encoded = encoded;
642+ oidpos++;
643+ }
644+ }
645+ gss_enc2oid[oidpos].oid = NULL;
646+ gss_enc2oid[oidpos].encoded = NULL;
647+
648+ buffer_put_char(&buf, '\0');
649+
650+ mechs = xmalloc(buffer_len(&buf));
651+ buffer_get(&buf, mechs, buffer_len(&buf));
652+ buffer_free(&buf);
653+
654+ if (strlen(mechs) == 0) {
655+ free(mechs);
656+ mechs = NULL;
657+ }
658+
659+ return (mechs);
660+}
661+
662+gss_OID
663+ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) {
664+ int i = 0;
665+
666+ switch (kex_type) {
667+ case KEX_GSS_GRP1_SHA1:
668+ if (strlen(name) < sizeof(KEX_GSS_GRP1_SHA1_ID))
669+ return GSS_C_NO_OID;
670+ name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1;
671+ break;
672+ case KEX_GSS_GRP14_SHA1:
673+ if (strlen(name) < sizeof(KEX_GSS_GRP14_SHA1_ID))
674+ return GSS_C_NO_OID;
675+ name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1;
676+ break;
677+ case KEX_GSS_GEX_SHA1:
678+ if (strlen(name) < sizeof(KEX_GSS_GEX_SHA1_ID))
679+ return GSS_C_NO_OID;
680+ name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1;
681+ break;
682+ default:
683+ return GSS_C_NO_OID;
684+ }
685+
686+ while (gss_enc2oid[i].encoded != NULL &&
687+ strcmp(name, gss_enc2oid[i].encoded) != 0)
688+ i++;
689+
690+ if (gss_enc2oid[i].oid != NULL && ctx != NULL)
691+ ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid);
692+
693+ return gss_enc2oid[i].oid;
694+}
695+
696 /* Check that the OID in a data stream matches that in the context */
697 int
698 ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
699@@ -197,7 +352,7 @@ ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
700 }
701
702 ctx->major = gss_init_sec_context(&ctx->minor,
703- GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
704+ ctx->client_creds, &ctx->context, ctx->name, ctx->oid,
705 GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
706 0, NULL, recv_tok, NULL, send_tok, flags, NULL);
707
708@@ -227,8 +382,42 @@ ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
709 }
710
711 OM_uint32
712+ssh_gssapi_client_identity(Gssctxt *ctx, const char *name)
713+{
714+ gss_buffer_desc gssbuf;
715+ gss_name_t gssname;
716+ OM_uint32 status;
717+ gss_OID_set oidset;
718+
719+ gssbuf.value = (void *) name;
720+ gssbuf.length = strlen(gssbuf.value);
721+
722+ gss_create_empty_oid_set(&status, &oidset);
723+ gss_add_oid_set_member(&status, ctx->oid, &oidset);
724+
725+ ctx->major = gss_import_name(&ctx->minor, &gssbuf,
726+ GSS_C_NT_USER_NAME, &gssname);
727+
728+ if (!ctx->major)
729+ ctx->major = gss_acquire_cred(&ctx->minor,
730+ gssname, 0, oidset, GSS_C_INITIATE,
731+ &ctx->client_creds, NULL, NULL);
732+
733+ gss_release_name(&status, &gssname);
734+ gss_release_oid_set(&status, &oidset);
735+
736+ if (ctx->major)
737+ ssh_gssapi_error(ctx);
738+
739+ return(ctx->major);
740+}
741+
742+OM_uint32
743 ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
744 {
745+ if (ctx == NULL)
746+ return -1;
747+
748 if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
749 GSS_C_QOP_DEFAULT, buffer, hash)))
750 ssh_gssapi_error(ctx);
751@@ -236,6 +425,19 @@ ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
752 return (ctx->major);
753 }
754
755+/* Priviledged when used by server */
756+OM_uint32
757+ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
758+{
759+ if (ctx == NULL)
760+ return -1;
761+
762+ ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
763+ gssbuf, gssmic, NULL);
764+
765+ return (ctx->major);
766+}
767+
768 void
769 ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
770 const char *context)
771@@ -249,11 +451,16 @@ ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
772 }
773
774 int
775-ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
776+ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host,
777+ const char *client)
778 {
779 gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
780 OM_uint32 major, minor;
781 gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
782+ Gssctxt *intctx = NULL;
783+
784+ if (ctx == NULL)
785+ ctx = &intctx;
786
787 /* RFC 4462 says we MUST NOT do SPNEGO */
788 if (oid->length == spnego_oid.length &&
789@@ -263,6 +470,10 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
790 ssh_gssapi_build_ctx(ctx);
791 ssh_gssapi_set_oid(*ctx, oid);
792 major = ssh_gssapi_import_name(*ctx, host);
793+
794+ if (!GSS_ERROR(major) && client)
795+ major = ssh_gssapi_client_identity(*ctx, client);
796+
797 if (!GSS_ERROR(major)) {
798 major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token,
799 NULL);
800@@ -272,10 +483,66 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
801 GSS_C_NO_BUFFER);
802 }
803
804- if (GSS_ERROR(major))
805+ if (GSS_ERROR(major) || intctx != NULL)
806 ssh_gssapi_delete_ctx(ctx);
807
808 return (!GSS_ERROR(major));
809 }
810
811+int
812+ssh_gssapi_credentials_updated(Gssctxt *ctxt) {
813+ static gss_name_t saved_name = GSS_C_NO_NAME;
814+ static OM_uint32 saved_lifetime = 0;
815+ static gss_OID saved_mech = GSS_C_NO_OID;
816+ static gss_name_t name;
817+ static OM_uint32 last_call = 0;
818+ OM_uint32 lifetime, now, major, minor;
819+ int equal;
820+
821+ now = time(NULL);
822+
823+ if (ctxt) {
824+ debug("Rekey has happened - updating saved versions");
825+
826+ if (saved_name != GSS_C_NO_NAME)
827+ gss_release_name(&minor, &saved_name);
828+
829+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
830+ &saved_name, &saved_lifetime, NULL, NULL);
831+
832+ if (!GSS_ERROR(major)) {
833+ saved_mech = ctxt->oid;
834+ saved_lifetime+= now;
835+ } else {
836+ /* Handle the error */
837+ }
838+ return 0;
839+ }
840+
841+ if (now - last_call < 10)
842+ return 0;
843+
844+ last_call = now;
845+
846+ if (saved_mech == GSS_C_NO_OID)
847+ return 0;
848+
849+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
850+ &name, &lifetime, NULL, NULL);
851+ if (major == GSS_S_CREDENTIALS_EXPIRED)
852+ return 0;
853+ else if (GSS_ERROR(major))
854+ return 0;
855+
856+ major = gss_compare_name(&minor, saved_name, name, &equal);
857+ gss_release_name(&minor, &name);
858+ if (GSS_ERROR(major))
859+ return 0;
860+
861+ if (equal && (saved_lifetime < lifetime + now - 10))
862+ return 1;
863+
864+ return 0;
865+}
866+
867 #endif /* GSSAPI */
868diff --git a/gss-serv-krb5.c b/gss-serv-krb5.c
869index 759fa10..e678a27 100644
870--- a/gss-serv-krb5.c
871+++ b/gss-serv-krb5.c
872@@ -1,7 +1,7 @@
873 /* $OpenBSD: gss-serv-krb5.c,v 1.8 2013/07/20 01:55:13 djm Exp $ */
874
875 /*
876- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
877+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
878 *
879 * Redistribution and use in source and binary forms, with or without
880 * modification, are permitted provided that the following conditions
881@@ -120,8 +120,8 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
882 krb5_error_code problem;
883 krb5_principal princ;
884 OM_uint32 maj_status, min_status;
885- int len;
886 const char *errmsg;
887+ const char *new_ccname;
888
889 if (client->creds == NULL) {
890 debug("No credentials stored");
891@@ -180,11 +180,16 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
892 return;
893 }
894
895- client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache));
896+ new_ccname = krb5_cc_get_name(krb_context, ccache);
897+
898 client->store.envvar = "KRB5CCNAME";
899- len = strlen(client->store.filename) + 6;
900- client->store.envval = xmalloc(len);
901- snprintf(client->store.envval, len, "FILE:%s", client->store.filename);
902+#ifdef USE_CCAPI
903+ xasprintf(&client->store.envval, "API:%s", new_ccname);
904+ client->store.filename = NULL;
905+#else
906+ xasprintf(&client->store.envval, "FILE:%s", new_ccname);
907+ client->store.filename = xstrdup(new_ccname);
908+#endif
909
910 #ifdef USE_PAM
911 if (options.use_pam)
912@@ -196,6 +201,71 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
913 return;
914 }
915
916+int
917+ssh_gssapi_krb5_updatecreds(ssh_gssapi_ccache *store,
918+ ssh_gssapi_client *client)
919+{
920+ krb5_ccache ccache = NULL;
921+ krb5_principal principal = NULL;
922+ char *name = NULL;
923+ krb5_error_code problem;
924+ OM_uint32 maj_status, min_status;
925+
926+ if ((problem = krb5_cc_resolve(krb_context, store->envval, &ccache))) {
927+ logit("krb5_cc_resolve(): %.100s",
928+ krb5_get_err_text(krb_context, problem));
929+ return 0;
930+ }
931+
932+ /* Find out who the principal in this cache is */
933+ if ((problem = krb5_cc_get_principal(krb_context, ccache,
934+ &principal))) {
935+ logit("krb5_cc_get_principal(): %.100s",
936+ krb5_get_err_text(krb_context, problem));
937+ krb5_cc_close(krb_context, ccache);
938+ return 0;
939+ }
940+
941+ if ((problem = krb5_unparse_name(krb_context, principal, &name))) {
942+ logit("krb5_unparse_name(): %.100s",
943+ krb5_get_err_text(krb_context, problem));
944+ krb5_free_principal(krb_context, principal);
945+ krb5_cc_close(krb_context, ccache);
946+ return 0;
947+ }
948+
949+
950+ if (strcmp(name,client->exportedname.value)!=0) {
951+ debug("Name in local credentials cache differs. Not storing");
952+ krb5_free_principal(krb_context, principal);
953+ krb5_cc_close(krb_context, ccache);
954+ krb5_free_unparsed_name(krb_context, name);
955+ return 0;
956+ }
957+ krb5_free_unparsed_name(krb_context, name);
958+
959+ /* Name matches, so lets get on with it! */
960+
961+ if ((problem = krb5_cc_initialize(krb_context, ccache, principal))) {
962+ logit("krb5_cc_initialize(): %.100s",
963+ krb5_get_err_text(krb_context, problem));
964+ krb5_free_principal(krb_context, principal);
965+ krb5_cc_close(krb_context, ccache);
966+ return 0;
967+ }
968+
969+ krb5_free_principal(krb_context, principal);
970+
971+ if ((maj_status = gss_krb5_copy_ccache(&min_status, client->creds,
972+ ccache))) {
973+ logit("gss_krb5_copy_ccache() failed. Sorry!");
974+ krb5_cc_close(krb_context, ccache);
975+ return 0;
976+ }
977+
978+ return 1;
979+}
980+
981 ssh_gssapi_mech gssapi_kerberos_mech = {
982 "toWM5Slw5Ew8Mqkay+al2g==",
983 "Kerberos",
984@@ -203,7 +273,8 @@ ssh_gssapi_mech gssapi_kerberos_mech = {
985 NULL,
986 &ssh_gssapi_krb5_userok,
987 NULL,
988- &ssh_gssapi_krb5_storecreds
989+ &ssh_gssapi_krb5_storecreds,
990+ &ssh_gssapi_krb5_updatecreds
991 };
992
993 #endif /* KRB5 */
994diff --git a/gss-serv.c b/gss-serv.c
995index e61b37b..c33463b 100644
996--- a/gss-serv.c
997+++ b/gss-serv.c
998@@ -1,7 +1,7 @@
999 /* $OpenBSD: gss-serv.c,v 1.26 2014/02/26 20:28:44 djm Exp $ */
1000
1001 /*
1002- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
1003+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
1004 *
1005 * Redistribution and use in source and binary forms, with or without
1006 * modification, are permitted provided that the following conditions
1007@@ -45,15 +45,21 @@
1008 #include "channels.h"
1009 #include "session.h"
1010 #include "misc.h"
1011+#include "servconf.h"
1012+#include "uidswap.h"
1013
1014 #include "ssh-gss.h"
1015+#include "monitor_wrap.h"
1016+
1017+extern ServerOptions options;
1018
1019 static ssh_gssapi_client gssapi_client =
1020 { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER,
1021- GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL, NULL}};
1022+ GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, NULL,
1023+ {NULL, NULL, NULL, NULL, NULL}, 0, 0};
1024
1025 ssh_gssapi_mech gssapi_null_mech =
1026- { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL};
1027+ { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL};
1028
1029 #ifdef KRB5
1030 extern ssh_gssapi_mech gssapi_kerberos_mech;
1031@@ -100,25 +106,32 @@ ssh_gssapi_acquire_cred(Gssctxt *ctx)
1032 char lname[MAXHOSTNAMELEN];
1033 gss_OID_set oidset;
1034
1035- gss_create_empty_oid_set(&status, &oidset);
1036- gss_add_oid_set_member(&status, ctx->oid, &oidset);
1037+ if (options.gss_strict_acceptor) {
1038+ gss_create_empty_oid_set(&status, &oidset);
1039+ gss_add_oid_set_member(&status, ctx->oid, &oidset);
1040
1041- if (gethostname(lname, MAXHOSTNAMELEN)) {
1042- gss_release_oid_set(&status, &oidset);
1043- return (-1);
1044- }
1045+ if (gethostname(lname, MAXHOSTNAMELEN)) {
1046+ gss_release_oid_set(&status, &oidset);
1047+ return (-1);
1048+ }
1049+
1050+ if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
1051+ gss_release_oid_set(&status, &oidset);
1052+ return (ctx->major);
1053+ }
1054+
1055+ if ((ctx->major = gss_acquire_cred(&ctx->minor,
1056+ ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds,
1057+ NULL, NULL)))
1058+ ssh_gssapi_error(ctx);
1059
1060- if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
1061 gss_release_oid_set(&status, &oidset);
1062 return (ctx->major);
1063+ } else {
1064+ ctx->name = GSS_C_NO_NAME;
1065+ ctx->creds = GSS_C_NO_CREDENTIAL;
1066 }
1067-
1068- if ((ctx->major = gss_acquire_cred(&ctx->minor,
1069- ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
1070- ssh_gssapi_error(ctx);
1071-
1072- gss_release_oid_set(&status, &oidset);
1073- return (ctx->major);
1074+ return GSS_S_COMPLETE;
1075 }
1076
1077 /* Privileged */
1078@@ -133,6 +146,29 @@ ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
1079 }
1080
1081 /* Unprivileged */
1082+char *
1083+ssh_gssapi_server_mechanisms(void) {
1084+ gss_OID_set supported;
1085+
1086+ ssh_gssapi_supported_oids(&supported);
1087+ return (ssh_gssapi_kex_mechs(supported, &ssh_gssapi_server_check_mech,
1088+ NULL, NULL));
1089+}
1090+
1091+/* Unprivileged */
1092+int
1093+ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data,
1094+ const char *dummy) {
1095+ Gssctxt *ctx = NULL;
1096+ int res;
1097+
1098+ res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid)));
1099+ ssh_gssapi_delete_ctx(&ctx);
1100+
1101+ return (res);
1102+}
1103+
1104+/* Unprivileged */
1105 void
1106 ssh_gssapi_supported_oids(gss_OID_set *oidset)
1107 {
1108@@ -142,7 +178,9 @@ ssh_gssapi_supported_oids(gss_OID_set *oidset)
1109 gss_OID_set supported;
1110
1111 gss_create_empty_oid_set(&min_status, oidset);
1112- gss_indicate_mechs(&min_status, &supported);
1113+
1114+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported)))
1115+ return;
1116
1117 while (supported_mechs[i]->name != NULL) {
1118 if (GSS_ERROR(gss_test_oid_set_member(&min_status,
1119@@ -268,8 +306,48 @@ OM_uint32
1120 ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
1121 {
1122 int i = 0;
1123+ int equal = 0;
1124+ gss_name_t new_name = GSS_C_NO_NAME;
1125+ gss_buffer_desc ename = GSS_C_EMPTY_BUFFER;
1126+
1127+ if (options.gss_store_rekey && client->used && ctx->client_creds) {
1128+ if (client->mech->oid.length != ctx->oid->length ||
1129+ (memcmp(client->mech->oid.elements,
1130+ ctx->oid->elements, ctx->oid->length) !=0)) {
1131+ debug("Rekeyed credentials have different mechanism");
1132+ return GSS_S_COMPLETE;
1133+ }
1134+
1135+ if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
1136+ ctx->client_creds, ctx->oid, &new_name,
1137+ NULL, NULL, NULL))) {
1138+ ssh_gssapi_error(ctx);
1139+ return (ctx->major);
1140+ }
1141+
1142+ ctx->major = gss_compare_name(&ctx->minor, client->name,
1143+ new_name, &equal);
1144
1145- gss_buffer_desc ename;
1146+ if (GSS_ERROR(ctx->major)) {
1147+ ssh_gssapi_error(ctx);
1148+ return (ctx->major);
1149+ }
1150+
1151+ if (!equal) {
1152+ debug("Rekeyed credentials have different name");
1153+ return GSS_S_COMPLETE;
1154+ }
1155+
1156+ debug("Marking rekeyed credentials for export");
1157+
1158+ gss_release_name(&ctx->minor, &client->name);
1159+ gss_release_cred(&ctx->minor, &client->creds);
1160+ client->name = new_name;
1161+ client->creds = ctx->client_creds;
1162+ ctx->client_creds = GSS_C_NO_CREDENTIAL;
1163+ client->updated = 1;
1164+ return GSS_S_COMPLETE;
1165+ }
1166
1167 client->mech = NULL;
1168
1169@@ -284,6 +362,13 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
1170 if (client->mech == NULL)
1171 return GSS_S_FAILURE;
1172
1173+ if (ctx->client_creds &&
1174+ (ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
1175+ ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) {
1176+ ssh_gssapi_error(ctx);
1177+ return (ctx->major);
1178+ }
1179+
1180 if ((ctx->major = gss_display_name(&ctx->minor, ctx->client,
1181 &client->displayname, NULL))) {
1182 ssh_gssapi_error(ctx);
1183@@ -301,6 +386,8 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
1184 return (ctx->major);
1185 }
1186
1187+ gss_release_buffer(&ctx->minor, &ename);
1188+
1189 /* We can't copy this structure, so we just move the pointer to it */
1190 client->creds = ctx->client_creds;
1191 ctx->client_creds = GSS_C_NO_CREDENTIAL;
1192@@ -348,7 +435,7 @@ ssh_gssapi_do_child(char ***envp, u_int *envsizep)
1193
1194 /* Privileged */
1195 int
1196-ssh_gssapi_userok(char *user)
1197+ssh_gssapi_userok(char *user, struct passwd *pw)
1198 {
1199 OM_uint32 lmin;
1200
1201@@ -358,9 +445,11 @@ ssh_gssapi_userok(char *user)
1202 return 0;
1203 }
1204 if (gssapi_client.mech && gssapi_client.mech->userok)
1205- if ((*gssapi_client.mech->userok)(&gssapi_client, user))
1206+ if ((*gssapi_client.mech->userok)(&gssapi_client, user)) {
1207+ gssapi_client.used = 1;
1208+ gssapi_client.store.owner = pw;
1209 return 1;
1210- else {
1211+ } else {
1212 /* Destroy delegated credentials if userok fails */
1213 gss_release_buffer(&lmin, &gssapi_client.displayname);
1214 gss_release_buffer(&lmin, &gssapi_client.exportedname);
1215@@ -374,14 +463,90 @@ ssh_gssapi_userok(char *user)
1216 return (0);
1217 }
1218
1219-/* Privileged */
1220-OM_uint32
1221-ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
1222+/* These bits are only used for rekeying. The unpriviledged child is running
1223+ * as the user, the monitor is root.
1224+ *
1225+ * In the child, we want to :
1226+ * *) Ask the monitor to store our credentials into the store we specify
1227+ * *) If it succeeds, maybe do a PAM update
1228+ */
1229+
1230+/* Stuff for PAM */
1231+
1232+#ifdef USE_PAM
1233+static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg,
1234+ struct pam_response **resp, void *data)
1235 {
1236- ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
1237- gssbuf, gssmic, NULL);
1238+ return (PAM_CONV_ERR);
1239+}
1240+#endif
1241
1242- return (ctx->major);
1243+void
1244+ssh_gssapi_rekey_creds(void) {
1245+ int ok;
1246+ int ret;
1247+#ifdef USE_PAM
1248+ pam_handle_t *pamh = NULL;
1249+ struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL};
1250+ char *envstr;
1251+#endif
1252+
1253+ if (gssapi_client.store.filename == NULL &&
1254+ gssapi_client.store.envval == NULL &&
1255+ gssapi_client.store.envvar == NULL)
1256+ return;
1257+
1258+ ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store));
1259+
1260+ if (!ok)
1261+ return;
1262+
1263+ debug("Rekeyed credentials stored successfully");
1264+
1265+ /* Actually managing to play with the ssh pam stack from here will
1266+ * be next to impossible. In any case, we may want different options
1267+ * for rekeying. So, use our own :)
1268+ */
1269+#ifdef USE_PAM
1270+ if (!use_privsep) {
1271+ debug("Not even going to try and do PAM with privsep disabled");
1272+ return;
1273+ }
1274+
1275+ ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name,
1276+ &pamconv, &pamh);
1277+ if (ret)
1278+ return;
1279+
1280+ xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar,
1281+ gssapi_client.store.envval);
1282+
1283+ ret = pam_putenv(pamh, envstr);
1284+ if (!ret)
1285+ pam_setcred(pamh, PAM_REINITIALIZE_CRED);
1286+ pam_end(pamh, PAM_SUCCESS);
1287+#endif
1288+}
1289+
1290+int
1291+ssh_gssapi_update_creds(ssh_gssapi_ccache *store) {
1292+ int ok = 0;
1293+
1294+ /* Check we've got credentials to store */
1295+ if (!gssapi_client.updated)
1296+ return 0;
1297+
1298+ gssapi_client.updated = 0;
1299+
1300+ temporarily_use_uid(gssapi_client.store.owner);
1301+ if (gssapi_client.mech && gssapi_client.mech->updatecreds)
1302+ ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client);
1303+ else
1304+ debug("No update function for this mechanism");
1305+
1306+ restore_uid();
1307+
1308+ return ok;
1309 }
1310
1311 #endif
1312diff --git a/kex.c b/kex.c
1313index 74e2b86..d114ee3 100644
1314--- a/kex.c
1315+++ b/kex.c
1316@@ -51,6 +51,10 @@
1317 #include "roaming.h"
1318 #include "digest.h"
1319
1320+#ifdef GSSAPI
1321+#include "ssh-gss.h"
1322+#endif
1323+
1324 #if OPENSSL_VERSION_NUMBER >= 0x00907000L
1325 # if defined(HAVE_EVP_SHA256)
1326 # define evp_ssh_sha256 EVP_sha256
1327@@ -92,6 +96,14 @@ static const struct kexalg kexalgs[] = {
1328 #endif
1329 { NULL, -1, -1, -1},
1330 };
1331+static const struct kexalg kexalg_prefixes[] = {
1332+#ifdef GSSAPI
1333+ { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
1334+ { KEX_GSS_GRP1_SHA1_ID, KEX_GSS_GRP1_SHA1, 0, SSH_DIGEST_SHA1 },
1335+ { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
1336+#endif
1337+ { NULL, -1, -1, -1 },
1338+};
1339
1340 char *
1341 kex_alg_list(char sep)
1342@@ -120,6 +132,10 @@ kex_alg_by_name(const char *name)
1343 if (strcmp(k->name, name) == 0)
1344 return k;
1345 }
1346+ for (k = kexalg_prefixes; k->name != NULL; k++) {
1347+ if (strncmp(k->name, name, strlen(k->name)) == 0)
1348+ return k;
1349+ }
1350 return NULL;
1351 }
1352
1353diff --git a/kex.h b/kex.h
1354index c85680e..ea698c4 100644
1355--- a/kex.h
1356+++ b/kex.h
1357@@ -76,6 +76,9 @@ enum kex_exchange {
1358 KEX_DH_GEX_SHA256,
1359 KEX_ECDH_SHA2,
1360 KEX_C25519_SHA256,
1361+ KEX_GSS_GRP1_SHA1,
1362+ KEX_GSS_GRP14_SHA1,
1363+ KEX_GSS_GEX_SHA1,
1364 KEX_MAX
1365 };
1366
1367@@ -135,6 +138,12 @@ struct Kex {
1368 int flags;
1369 int hash_alg;
1370 int ec_nid;
1371+#ifdef GSSAPI
1372+ int gss_deleg_creds;
1373+ int gss_trust_dns;
1374+ char *gss_host;
1375+ char *gss_client;
1376+#endif
1377 char *client_version_string;
1378 char *server_version_string;
1379 int (*verify_host_key)(Key *);
1380@@ -167,6 +176,11 @@ void kexecdh_server(Kex *);
1381 void kexc25519_client(Kex *);
1382 void kexc25519_server(Kex *);
1383
1384+#ifdef GSSAPI
1385+void kexgss_client(Kex *);
1386+void kexgss_server(Kex *);
1387+#endif
1388+
1389 void
1390 kex_dh_hash(char *, char *, char *, int, char *, int, u_char *, int,
1391 BIGNUM *, BIGNUM *, BIGNUM *, u_char **, u_int *);
1392diff --git a/kexgssc.c b/kexgssc.c
1393new file mode 100644
1394index 0000000..92a31c5
1395--- /dev/null
1396+++ b/kexgssc.c
1397@@ -0,0 +1,332 @@
1398+/*
1399+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
1400+ *
1401+ * Redistribution and use in source and binary forms, with or without
1402+ * modification, are permitted provided that the following conditions
1403+ * are met:
1404+ * 1. Redistributions of source code must retain the above copyright
1405+ * notice, this list of conditions and the following disclaimer.
1406+ * 2. Redistributions in binary form must reproduce the above copyright
1407+ * notice, this list of conditions and the following disclaimer in the
1408+ * documentation and/or other materials provided with the distribution.
1409+ *
1410+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
1411+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
1412+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
1413+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
1414+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
1415+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1416+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1417+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1418+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1419+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1420+ */
1421+
1422+#include "includes.h"
1423+
1424+#ifdef GSSAPI
1425+
1426+#include "includes.h"
1427+
1428+#include <openssl/crypto.h>
1429+#include <openssl/bn.h>
1430+
1431+#include <string.h>
1432+
1433+#include "xmalloc.h"
1434+#include "buffer.h"
1435+#include "ssh2.h"
1436+#include "key.h"
1437+#include "cipher.h"
1438+#include "kex.h"
1439+#include "log.h"
1440+#include "packet.h"
1441+#include "dh.h"
1442+
1443+#include "ssh-gss.h"
1444+
1445+void
1446+kexgss_client(Kex *kex) {
1447+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1448+ gss_buffer_desc recv_tok, gssbuf, msg_tok, *token_ptr;
1449+ Gssctxt *ctxt;
1450+ OM_uint32 maj_status, min_status, ret_flags;
1451+ u_int klen, kout, slen = 0, hashlen, strlen;
1452+ DH *dh;
1453+ BIGNUM *dh_server_pub = NULL;
1454+ BIGNUM *shared_secret = NULL;
1455+ BIGNUM *p = NULL;
1456+ BIGNUM *g = NULL;
1457+ u_char *kbuf, *hash;
1458+ u_char *serverhostkey = NULL;
1459+ u_char *empty = "";
1460+ char *msg;
1461+ int type = 0;
1462+ int first = 1;
1463+ int nbits = 0, min = DH_GRP_MIN, max = DH_GRP_MAX;
1464+
1465+ /* Initialise our GSSAPI world */
1466+ ssh_gssapi_build_ctx(&ctxt);
1467+ if (ssh_gssapi_id_kex(ctxt, kex->name, kex->kex_type)
1468+ == GSS_C_NO_OID)
1469+ fatal("Couldn't identify host exchange");
1470+
1471+ if (ssh_gssapi_import_name(ctxt, kex->gss_host))
1472+ fatal("Couldn't import hostname");
1473+
1474+ if (kex->gss_client &&
1475+ ssh_gssapi_client_identity(ctxt, kex->gss_client))
1476+ fatal("Couldn't acquire client credentials");
1477+
1478+ switch (kex->kex_type) {
1479+ case KEX_GSS_GRP1_SHA1:
1480+ dh = dh_new_group1();
1481+ break;
1482+ case KEX_GSS_GRP14_SHA1:
1483+ dh = dh_new_group14();
1484+ break;
1485+ case KEX_GSS_GEX_SHA1:
1486+ debug("Doing group exchange\n");
1487+ nbits = dh_estimate(kex->we_need * 8);
1488+ packet_start(SSH2_MSG_KEXGSS_GROUPREQ);
1489+ packet_put_int(min);
1490+ packet_put_int(nbits);
1491+ packet_put_int(max);
1492+
1493+ packet_send();
1494+
1495+ packet_read_expect(SSH2_MSG_KEXGSS_GROUP);
1496+
1497+ if ((p = BN_new()) == NULL)
1498+ fatal("BN_new() failed");
1499+ packet_get_bignum2(p);
1500+ if ((g = BN_new()) == NULL)
1501+ fatal("BN_new() failed");
1502+ packet_get_bignum2(g);
1503+ packet_check_eom();
1504+
1505+ if (BN_num_bits(p) < min || BN_num_bits(p) > max)
1506+ fatal("GSSGRP_GEX group out of range: %d !< %d !< %d",
1507+ min, BN_num_bits(p), max);
1508+
1509+ dh = dh_new_group(g, p);
1510+ break;
1511+ default:
1512+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
1513+ }
1514+
1515+ /* Step 1 - e is dh->pub_key */
1516+ dh_gen_key(dh, kex->we_need * 8);
1517+
1518+ /* This is f, we initialise it now to make life easier */
1519+ dh_server_pub = BN_new();
1520+ if (dh_server_pub == NULL)
1521+ fatal("dh_server_pub == NULL");
1522+
1523+ token_ptr = GSS_C_NO_BUFFER;
1524+
1525+ do {
1526+ debug("Calling gss_init_sec_context");
1527+
1528+ maj_status = ssh_gssapi_init_ctx(ctxt,
1529+ kex->gss_deleg_creds, token_ptr, &send_tok,
1530+ &ret_flags);
1531+
1532+ if (GSS_ERROR(maj_status)) {
1533+ if (send_tok.length != 0) {
1534+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
1535+ packet_put_string(send_tok.value,
1536+ send_tok.length);
1537+ }
1538+ fatal("gss_init_context failed");
1539+ }
1540+
1541+ /* If we've got an old receive buffer get rid of it */
1542+ if (token_ptr != GSS_C_NO_BUFFER)
1543+ free(recv_tok.value);
1544+
1545+ if (maj_status == GSS_S_COMPLETE) {
1546+ /* If mutual state flag is not true, kex fails */
1547+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
1548+ fatal("Mutual authentication failed");
1549+
1550+ /* If integ avail flag is not true kex fails */
1551+ if (!(ret_flags & GSS_C_INTEG_FLAG))
1552+ fatal("Integrity check failed");
1553+ }
1554+
1555+ /*
1556+ * If we have data to send, then the last message that we
1557+ * received cannot have been a 'complete'.
1558+ */
1559+ if (send_tok.length != 0) {
1560+ if (first) {
1561+ packet_start(SSH2_MSG_KEXGSS_INIT);
1562+ packet_put_string(send_tok.value,
1563+ send_tok.length);
1564+ packet_put_bignum2(dh->pub_key);
1565+ first = 0;
1566+ } else {
1567+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
1568+ packet_put_string(send_tok.value,
1569+ send_tok.length);
1570+ }
1571+ packet_send();
1572+ gss_release_buffer(&min_status, &send_tok);
1573+
1574+ /* If we've sent them data, they should reply */
1575+ do {
1576+ type = packet_read();
1577+ if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
1578+ debug("Received KEXGSS_HOSTKEY");
1579+ if (serverhostkey)
1580+ fatal("Server host key received more than once");
1581+ serverhostkey =
1582+ packet_get_string(&slen);
1583+ }
1584+ } while (type == SSH2_MSG_KEXGSS_HOSTKEY);
1585+
1586+ switch (type) {
1587+ case SSH2_MSG_KEXGSS_CONTINUE:
1588+ debug("Received GSSAPI_CONTINUE");
1589+ if (maj_status == GSS_S_COMPLETE)
1590+ fatal("GSSAPI Continue received from server when complete");
1591+ recv_tok.value = packet_get_string(&strlen);
1592+ recv_tok.length = strlen;
1593+ break;
1594+ case SSH2_MSG_KEXGSS_COMPLETE:
1595+ debug("Received GSSAPI_COMPLETE");
1596+ packet_get_bignum2(dh_server_pub);
1597+ msg_tok.value = packet_get_string(&strlen);
1598+ msg_tok.length = strlen;
1599+
1600+ /* Is there a token included? */
1601+ if (packet_get_char()) {
1602+ recv_tok.value=
1603+ packet_get_string(&strlen);
1604+ recv_tok.length = strlen;
1605+ /* If we're already complete - protocol error */
1606+ if (maj_status == GSS_S_COMPLETE)
1607+ packet_disconnect("Protocol error: received token when complete");
1608+ } else {
1609+ /* No token included */
1610+ if (maj_status != GSS_S_COMPLETE)
1611+ packet_disconnect("Protocol error: did not receive final token");
1612+ }
1613+ break;
1614+ case SSH2_MSG_KEXGSS_ERROR:
1615+ debug("Received Error");
1616+ maj_status = packet_get_int();
1617+ min_status = packet_get_int();
1618+ msg = packet_get_string(NULL);
1619+ (void) packet_get_string_ptr(NULL);
1620+ fatal("GSSAPI Error: \n%.400s",msg);
1621+ default:
1622+ packet_disconnect("Protocol error: didn't expect packet type %d",
1623+ type);
1624+ }
1625+ token_ptr = &recv_tok;
1626+ } else {
1627+ /* No data, and not complete */
1628+ if (maj_status != GSS_S_COMPLETE)
1629+ fatal("Not complete, and no token output");
1630+ }
1631+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
1632+
1633+ /*
1634+ * We _must_ have received a COMPLETE message in reply from the
1635+ * server, which will have set dh_server_pub and msg_tok
1636+ */
1637+
1638+ if (type != SSH2_MSG_KEXGSS_COMPLETE)
1639+ fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it");
1640+
1641+ /* Check f in range [1, p-1] */
1642+ if (!dh_pub_is_valid(dh, dh_server_pub))
1643+ packet_disconnect("bad server public DH value");
1644+
1645+ /* compute K=f^x mod p */
1646+ klen = DH_size(dh);
1647+ kbuf = xmalloc(klen);
1648+ kout = DH_compute_key(kbuf, dh_server_pub, dh);
1649+ if (kout < 0)
1650+ fatal("DH_compute_key: failed");
1651+
1652+ shared_secret = BN_new();
1653+ if (shared_secret == NULL)
1654+ fatal("kexgss_client: BN_new failed");
1655+
1656+ if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
1657+ fatal("kexdh_client: BN_bin2bn failed");
1658+
1659+ memset(kbuf, 0, klen);
1660+ free(kbuf);
1661+
1662+ switch (kex->kex_type) {
1663+ case KEX_GSS_GRP1_SHA1:
1664+ case KEX_GSS_GRP14_SHA1:
1665+ kex_dh_hash( kex->client_version_string,
1666+ kex->server_version_string,
1667+ buffer_ptr(&kex->my), buffer_len(&kex->my),
1668+ buffer_ptr(&kex->peer), buffer_len(&kex->peer),
1669+ (serverhostkey ? serverhostkey : empty), slen,
1670+ dh->pub_key, /* e */
1671+ dh_server_pub, /* f */
1672+ shared_secret, /* K */
1673+ &hash, &hashlen
1674+ );
1675+ break;
1676+ case KEX_GSS_GEX_SHA1:
1677+ kexgex_hash(
1678+ kex->hash_alg,
1679+ kex->client_version_string,
1680+ kex->server_version_string,
1681+ buffer_ptr(&kex->my), buffer_len(&kex->my),
1682+ buffer_ptr(&kex->peer), buffer_len(&kex->peer),
1683+ (serverhostkey ? serverhostkey : empty), slen,
1684+ min, nbits, max,
1685+ dh->p, dh->g,
1686+ dh->pub_key,
1687+ dh_server_pub,
1688+ shared_secret,
1689+ &hash, &hashlen
1690+ );
1691+ break;
1692+ default:
1693+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
1694+ }
1695+
1696+ gssbuf.value = hash;
1697+ gssbuf.length = hashlen;
1698+
1699+ /* Verify that the hash matches the MIC we just got. */
1700+ if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok)))
1701+ packet_disconnect("Hash's MIC didn't verify");
1702+
1703+ free(msg_tok.value);
1704+
1705+ DH_free(dh);
1706+ free(serverhostkey);
1707+ BN_clear_free(dh_server_pub);
1708+
1709+ /* save session id */
1710+ if (kex->session_id == NULL) {
1711+ kex->session_id_len = hashlen;
1712+ kex->session_id = xmalloc(kex->session_id_len);
1713+ memcpy(kex->session_id, hash, kex->session_id_len);
1714+ }
1715+
1716+ if (kex->gss_deleg_creds)
1717+ ssh_gssapi_credentials_updated(ctxt);
1718+
1719+ if (gss_kex_context == NULL)
1720+ gss_kex_context = ctxt;
1721+ else
1722+ ssh_gssapi_delete_ctx(&ctxt);
1723+
1724+ kex_derive_keys_bn(kex, hash, hashlen, shared_secret);
1725+ BN_clear_free(shared_secret);
1726+ kex_finish(kex);
1727+}
1728+
1729+#endif /* GSSAPI */
1730diff --git a/kexgsss.c b/kexgsss.c
1731new file mode 100644
1732index 0000000..8095259
1733--- /dev/null
1734+++ b/kexgsss.c
1735@@ -0,0 +1,289 @@
1736+/*
1737+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
1738+ *
1739+ * Redistribution and use in source and binary forms, with or without
1740+ * modification, are permitted provided that the following conditions
1741+ * are met:
1742+ * 1. Redistributions of source code must retain the above copyright
1743+ * notice, this list of conditions and the following disclaimer.
1744+ * 2. Redistributions in binary form must reproduce the above copyright
1745+ * notice, this list of conditions and the following disclaimer in the
1746+ * documentation and/or other materials provided with the distribution.
1747+ *
1748+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
1749+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
1750+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
1751+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
1752+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
1753+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1754+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1755+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1756+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1757+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1758+ */
1759+
1760+#include "includes.h"
1761+
1762+#ifdef GSSAPI
1763+
1764+#include <string.h>
1765+
1766+#include <openssl/crypto.h>
1767+#include <openssl/bn.h>
1768+
1769+#include "xmalloc.h"
1770+#include "buffer.h"
1771+#include "ssh2.h"
1772+#include "key.h"
1773+#include "cipher.h"
1774+#include "kex.h"
1775+#include "log.h"
1776+#include "packet.h"
1777+#include "dh.h"
1778+#include "ssh-gss.h"
1779+#include "monitor_wrap.h"
1780+#include "servconf.h"
1781+
1782+extern ServerOptions options;
1783+
1784+void
1785+kexgss_server(Kex *kex)
1786+{
1787+ OM_uint32 maj_status, min_status;
1788+
1789+ /*
1790+ * Some GSSAPI implementations use the input value of ret_flags (an
1791+ * output variable) as a means of triggering mechanism specific
1792+ * features. Initializing it to zero avoids inadvertently
1793+ * activating this non-standard behaviour.
1794+ */
1795+
1796+ OM_uint32 ret_flags = 0;
1797+ gss_buffer_desc gssbuf, recv_tok, msg_tok;
1798+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1799+ Gssctxt *ctxt = NULL;
1800+ u_int slen, klen, kout, hashlen;
1801+ u_char *kbuf, *hash;
1802+ DH *dh;
1803+ int min = -1, max = -1, nbits = -1;
1804+ BIGNUM *shared_secret = NULL;
1805+ BIGNUM *dh_client_pub = NULL;
1806+ int type = 0;
1807+ gss_OID oid;
1808+ char *mechs;
1809+
1810+ /* Initialise GSSAPI */
1811+
1812+ /* If we're rekeying, privsep means that some of the private structures
1813+ * in the GSSAPI code are no longer available. This kludges them back
1814+ * into life
1815+ */
1816+ if (!ssh_gssapi_oid_table_ok()) {
1817+ mechs = ssh_gssapi_server_mechanisms();
1818+ free(mechs);
1819+ }
1820+
1821+ debug2("%s: Identifying %s", __func__, kex->name);
1822+ oid = ssh_gssapi_id_kex(NULL, kex->name, kex->kex_type);
1823+ if (oid == GSS_C_NO_OID)
1824+ fatal("Unknown gssapi mechanism");
1825+
1826+ debug2("%s: Acquiring credentials", __func__);
1827+
1828+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid))))
1829+ fatal("Unable to acquire credentials for the server");
1830+
1831+ switch (kex->kex_type) {
1832+ case KEX_GSS_GRP1_SHA1:
1833+ dh = dh_new_group1();
1834+ break;
1835+ case KEX_GSS_GRP14_SHA1:
1836+ dh = dh_new_group14();
1837+ break;
1838+ case KEX_GSS_GEX_SHA1:
1839+ debug("Doing group exchange");
1840+ packet_read_expect(SSH2_MSG_KEXGSS_GROUPREQ);
1841+ min = packet_get_int();
1842+ nbits = packet_get_int();
1843+ max = packet_get_int();
1844+ min = MAX(DH_GRP_MIN, min);
1845+ max = MIN(DH_GRP_MAX, max);
1846+ packet_check_eom();
1847+ if (max < min || nbits < min || max < nbits)
1848+ fatal("GSS_GEX, bad parameters: %d !< %d !< %d",
1849+ min, nbits, max);
1850+ dh = PRIVSEP(choose_dh(min, nbits, max));
1851+ if (dh == NULL)
1852+ packet_disconnect("Protocol error: no matching group found");
1853+
1854+ packet_start(SSH2_MSG_KEXGSS_GROUP);
1855+ packet_put_bignum2(dh->p);
1856+ packet_put_bignum2(dh->g);
1857+ packet_send();
1858+
1859+ packet_write_wait();
1860+ break;
1861+ default:
1862+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
1863+ }
1864+
1865+ dh_gen_key(dh, kex->we_need * 8);
1866+
1867+ do {
1868+ debug("Wait SSH2_MSG_GSSAPI_INIT");
1869+ type = packet_read();
1870+ switch(type) {
1871+ case SSH2_MSG_KEXGSS_INIT:
1872+ if (dh_client_pub != NULL)
1873+ fatal("Received KEXGSS_INIT after initialising");
1874+ recv_tok.value = packet_get_string(&slen);
1875+ recv_tok.length = slen;
1876+
1877+ if ((dh_client_pub = BN_new()) == NULL)
1878+ fatal("dh_client_pub == NULL");
1879+
1880+ packet_get_bignum2(dh_client_pub);
1881+
1882+ /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */
1883+ break;
1884+ case SSH2_MSG_KEXGSS_CONTINUE:
1885+ recv_tok.value = packet_get_string(&slen);
1886+ recv_tok.length = slen;
1887+ break;
1888+ default:
1889+ packet_disconnect(
1890+ "Protocol error: didn't expect packet type %d",
1891+ type);
1892+ }
1893+
1894+ maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok,
1895+ &send_tok, &ret_flags));
1896+
1897+ free(recv_tok.value);
1898+
1899+ if (maj_status != GSS_S_COMPLETE && send_tok.length == 0)
1900+ fatal("Zero length token output when incomplete");
1901+
1902+ if (dh_client_pub == NULL)
1903+ fatal("No client public key");
1904+
1905+ if (maj_status & GSS_S_CONTINUE_NEEDED) {
1906+ debug("Sending GSSAPI_CONTINUE");
1907+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
1908+ packet_put_string(send_tok.value, send_tok.length);
1909+ packet_send();
1910+ gss_release_buffer(&min_status, &send_tok);
1911+ }
1912+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
1913+
1914+ if (GSS_ERROR(maj_status)) {
1915+ if (send_tok.length > 0) {
1916+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
1917+ packet_put_string(send_tok.value, send_tok.length);
1918+ packet_send();
1919+ }
1920+ fatal("accept_ctx died");
1921+ }
1922+
1923+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
1924+ fatal("Mutual Authentication flag wasn't set");
1925+
1926+ if (!(ret_flags & GSS_C_INTEG_FLAG))
1927+ fatal("Integrity flag wasn't set");
1928+
1929+ if (!dh_pub_is_valid(dh, dh_client_pub))
1930+ packet_disconnect("bad client public DH value");
1931+
1932+ klen = DH_size(dh);
1933+ kbuf = xmalloc(klen);
1934+ kout = DH_compute_key(kbuf, dh_client_pub, dh);
1935+ if (kout < 0)
1936+ fatal("DH_compute_key: failed");
1937+
1938+ shared_secret = BN_new();
1939+ if (shared_secret == NULL)
1940+ fatal("kexgss_server: BN_new failed");
1941+
1942+ if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
1943+ fatal("kexgss_server: BN_bin2bn failed");
1944+
1945+ memset(kbuf, 0, klen);
1946+ free(kbuf);
1947+
1948+ switch (kex->kex_type) {
1949+ case KEX_GSS_GRP1_SHA1:
1950+ case KEX_GSS_GRP14_SHA1:
1951+ kex_dh_hash(
1952+ kex->client_version_string, kex->server_version_string,
1953+ buffer_ptr(&kex->peer), buffer_len(&kex->peer),
1954+ buffer_ptr(&kex->my), buffer_len(&kex->my),
1955+ NULL, 0, /* Change this if we start sending host keys */
1956+ dh_client_pub, dh->pub_key, shared_secret,
1957+ &hash, &hashlen
1958+ );
1959+ break;
1960+ case KEX_GSS_GEX_SHA1:
1961+ kexgex_hash(
1962+ kex->hash_alg,
1963+ kex->client_version_string, kex->server_version_string,
1964+ buffer_ptr(&kex->peer), buffer_len(&kex->peer),
1965+ buffer_ptr(&kex->my), buffer_len(&kex->my),
1966+ NULL, 0,
1967+ min, nbits, max,
1968+ dh->p, dh->g,
1969+ dh_client_pub,
1970+ dh->pub_key,
1971+ shared_secret,
1972+ &hash, &hashlen
1973+ );
1974+ break;
1975+ default:
1976+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
1977+ }
1978+
1979+ BN_clear_free(dh_client_pub);
1980+
1981+ if (kex->session_id == NULL) {
1982+ kex->session_id_len = hashlen;
1983+ kex->session_id = xmalloc(kex->session_id_len);
1984+ memcpy(kex->session_id, hash, kex->session_id_len);
1985+ }
1986+
1987+ gssbuf.value = hash;
1988+ gssbuf.length = hashlen;
1989+
1990+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt,&gssbuf,&msg_tok))))
1991+ fatal("Couldn't get MIC");
1992+
1993+ packet_start(SSH2_MSG_KEXGSS_COMPLETE);
1994+ packet_put_bignum2(dh->pub_key);
1995+ packet_put_string(msg_tok.value,msg_tok.length);
1996+
1997+ if (send_tok.length != 0) {
1998+ packet_put_char(1); /* true */
1999+ packet_put_string(send_tok.value, send_tok.length);
2000+ } else {
2001+ packet_put_char(0); /* false */
2002+ }
2003+ packet_send();
2004+
2005+ gss_release_buffer(&min_status, &send_tok);
2006+ gss_release_buffer(&min_status, &msg_tok);
2007+
2008+ if (gss_kex_context == NULL)
2009+ gss_kex_context = ctxt;
2010+ else
2011+ ssh_gssapi_delete_ctx(&ctxt);
2012+
2013+ DH_free(dh);
2014+
2015+ kex_derive_keys_bn(kex, hash, hashlen, shared_secret);
2016+ BN_clear_free(shared_secret);
2017+ kex_finish(kex);
2018+
2019+ /* If this was a rekey, then save out any delegated credentials we
2020+ * just exchanged. */
2021+ if (options.gss_store_rekey)
2022+ ssh_gssapi_rekey_creds();
2023+}
2024+#endif /* GSSAPI */
2025diff --git a/key.c b/key.c
2026index 168e1b7..3d640e7 100644
2027--- a/key.c
2028+++ b/key.c
2029@@ -985,6 +985,7 @@ static const struct keytype keytypes[] = {
2030 KEY_DSA_CERT_V00, 0, 1 },
2031 { "ssh-ed25519-cert-v01@openssh.com", "ED25519-CERT",
2032 KEY_ED25519_CERT, 0, 1 },
2033+ { "null", "null", KEY_NULL, 0, 0 },
2034 { NULL, NULL, -1, -1, 0 }
2035 };
2036
2037@@ -1063,7 +1064,7 @@ key_alg_list(int certs_only, int plain_only)
2038 const struct keytype *kt;
2039
2040 for (kt = keytypes; kt->type != -1; kt++) {
2041- if (kt->name == NULL)
2042+ if (kt->name == NULL || kt->type == KEY_NULL)
2043 continue;
2044 if ((certs_only && !kt->cert) || (plain_only && kt->cert))
2045 continue;
2046diff --git a/key.h b/key.h
2047index d8ad13d..c8aeba2 100644
2048--- a/key.h
2049+++ b/key.h
2050@@ -46,6 +46,7 @@ enum types {
2051 KEY_ED25519_CERT,
2052 KEY_RSA_CERT_V00,
2053 KEY_DSA_CERT_V00,
2054+ KEY_NULL,
2055 KEY_UNSPEC
2056 };
2057 enum fp_type {
2058diff --git a/monitor.c b/monitor.c
2059index 531c4f9..2918814 100644
2060--- a/monitor.c
2061+++ b/monitor.c
2062@@ -175,6 +175,8 @@ int mm_answer_gss_setup_ctx(int, Buffer *);
2063 int mm_answer_gss_accept_ctx(int, Buffer *);
2064 int mm_answer_gss_userok(int, Buffer *);
2065 int mm_answer_gss_checkmic(int, Buffer *);
2066+int mm_answer_gss_sign(int, Buffer *);
2067+int mm_answer_gss_updatecreds(int, Buffer *);
2068 #endif
2069
2070 #ifdef SSH_AUDIT_EVENTS
2071@@ -247,11 +249,18 @@ struct mon_table mon_dispatch_proto20[] = {
2072 {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
2073 {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
2074 {MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
2075+ {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign},
2076 #endif
2077 {0, 0, NULL}
2078 };
2079
2080 struct mon_table mon_dispatch_postauth20[] = {
2081+#ifdef GSSAPI
2082+ {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx},
2083+ {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
2084+ {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign},
2085+ {MONITOR_REQ_GSSUPCREDS, 0, mm_answer_gss_updatecreds},
2086+#endif
2087 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
2088 {MONITOR_REQ_SIGN, 0, mm_answer_sign},
2089 {MONITOR_REQ_PTY, 0, mm_answer_pty},
2090@@ -360,6 +369,10 @@ monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
2091 /* Permit requests for moduli and signatures */
2092 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
2093 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
2094+#ifdef GSSAPI
2095+ /* and for the GSSAPI key exchange */
2096+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
2097+#endif
2098 } else {
2099 mon_dispatch = mon_dispatch_proto15;
2100
2101@@ -465,6 +478,10 @@ monitor_child_postauth(struct monitor *pmonitor)
2102 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
2103 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
2104 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
2105+#ifdef GSSAPI
2106+ /* and for the GSSAPI key exchange */
2107+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
2108+#endif
2109 } else {
2110 mon_dispatch = mon_dispatch_postauth15;
2111 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
2112@@ -1834,6 +1851,13 @@ mm_get_kex(Buffer *m)
2113 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
2114 kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
2115 kex->kex[KEX_C25519_SHA256] = kexc25519_server;
2116+#ifdef GSSAPI
2117+ if (options.gss_keyex) {
2118+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
2119+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
2120+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
2121+ }
2122+#endif
2123 kex->server = 1;
2124 kex->hostkey_type = buffer_get_int(m);
2125 kex->kex_type = buffer_get_int(m);
2126@@ -2041,6 +2065,9 @@ mm_answer_gss_setup_ctx(int sock, Buffer *m)
2127 OM_uint32 major;
2128 u_int len;
2129
2130+ if (!options.gss_authentication && !options.gss_keyex)
2131+ fatal("In GSSAPI monitor when GSSAPI is disabled");
2132+
2133 goid.elements = buffer_get_string(m, &len);
2134 goid.length = len;
2135
2136@@ -2068,6 +2095,9 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m)
2137 OM_uint32 flags = 0; /* GSI needs this */
2138 u_int len;
2139
2140+ if (!options.gss_authentication && !options.gss_keyex)
2141+ fatal("In GSSAPI monitor when GSSAPI is disabled");
2142+
2143 in.value = buffer_get_string(m, &len);
2144 in.length = len;
2145 major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
2146@@ -2085,6 +2115,7 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m)
2147 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
2148 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2149 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
2150+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN, 1);
2151 }
2152 return (0);
2153 }
2154@@ -2096,6 +2127,9 @@ mm_answer_gss_checkmic(int sock, Buffer *m)
2155 OM_uint32 ret;
2156 u_int len;
2157
2158+ if (!options.gss_authentication && !options.gss_keyex)
2159+ fatal("In GSSAPI monitor when GSSAPI is disabled");
2160+
2161 gssbuf.value = buffer_get_string(m, &len);
2162 gssbuf.length = len;
2163 mic.value = buffer_get_string(m, &len);
2164@@ -2122,7 +2156,11 @@ mm_answer_gss_userok(int sock, Buffer *m)
2165 {
2166 int authenticated;
2167
2168- authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
2169+ if (!options.gss_authentication && !options.gss_keyex)
2170+ fatal("In GSSAPI monitor when GSSAPI is disabled");
2171+
2172+ authenticated = authctxt->valid &&
2173+ ssh_gssapi_userok(authctxt->user, authctxt->pw);
2174
2175 buffer_clear(m);
2176 buffer_put_int(m, authenticated);
2177@@ -2135,5 +2173,73 @@ mm_answer_gss_userok(int sock, Buffer *m)
2178 /* Monitor loop will terminate if authenticated */
2179 return (authenticated);
2180 }
2181+
2182+int
2183+mm_answer_gss_sign(int socket, Buffer *m)
2184+{
2185+ gss_buffer_desc data;
2186+ gss_buffer_desc hash = GSS_C_EMPTY_BUFFER;
2187+ OM_uint32 major, minor;
2188+ u_int len;
2189+
2190+ if (!options.gss_authentication && !options.gss_keyex)
2191+ fatal("In GSSAPI monitor when GSSAPI is disabled");
2192+
2193+ data.value = buffer_get_string(m, &len);
2194+ data.length = len;
2195+ if (data.length != 20)
2196+ fatal("%s: data length incorrect: %d", __func__,
2197+ (int) data.length);
2198+
2199+ /* Save the session ID on the first time around */
2200+ if (session_id2_len == 0) {
2201+ session_id2_len = data.length;
2202+ session_id2 = xmalloc(session_id2_len);
2203+ memcpy(session_id2, data.value, session_id2_len);
2204+ }
2205+ major = ssh_gssapi_sign(gsscontext, &data, &hash);
2206+
2207+ free(data.value);
2208+
2209+ buffer_clear(m);
2210+ buffer_put_int(m, major);
2211+ buffer_put_string(m, hash.value, hash.length);
2212+
2213+ mm_request_send(socket, MONITOR_ANS_GSSSIGN, m);
2214+
2215+ gss_release_buffer(&minor, &hash);
2216+
2217+ /* Turn on getpwnam permissions */
2218+ monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
2219+
2220+ /* And credential updating, for when rekeying */
2221+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSUPCREDS, 1);
2222+
2223+ return (0);
2224+}
2225+
2226+int
2227+mm_answer_gss_updatecreds(int socket, Buffer *m) {
2228+ ssh_gssapi_ccache store;
2229+ int ok;
2230+
2231+ store.filename = buffer_get_string(m, NULL);
2232+ store.envvar = buffer_get_string(m, NULL);
2233+ store.envval = buffer_get_string(m, NULL);
2234+
2235+ ok = ssh_gssapi_update_creds(&store);
2236+
2237+ free(store.filename);
2238+ free(store.envvar);
2239+ free(store.envval);
2240+
2241+ buffer_clear(m);
2242+ buffer_put_int(m, ok);
2243+
2244+ mm_request_send(socket, MONITOR_ANS_GSSUPCREDS, m);
2245+
2246+ return(0);
2247+}
2248+
2249 #endif /* GSSAPI */
2250
2251diff --git a/monitor.h b/monitor.h
2252index 5bc41b5..7f32b0c 100644
2253--- a/monitor.h
2254+++ b/monitor.h
2255@@ -65,6 +65,9 @@ enum monitor_reqtype {
2256 MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111,
2257 MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113,
2258
2259+ MONITOR_REQ_GSSSIGN = 150, MONITOR_ANS_GSSSIGN = 151,
2260+ MONITOR_REQ_GSSUPCREDS = 152, MONITOR_ANS_GSSUPCREDS = 153,
2261+
2262 };
2263
2264 struct mm_master;
2265diff --git a/monitor_wrap.c b/monitor_wrap.c
2266index 1a47e41..60b987d 100644
2267--- a/monitor_wrap.c
2268+++ b/monitor_wrap.c
2269@@ -1271,7 +1271,7 @@ mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
2270 }
2271
2272 int
2273-mm_ssh_gssapi_userok(char *user)
2274+mm_ssh_gssapi_userok(char *user, struct passwd *pw)
2275 {
2276 Buffer m;
2277 int authenticated = 0;
2278@@ -1288,5 +1288,50 @@ mm_ssh_gssapi_userok(char *user)
2279 debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
2280 return (authenticated);
2281 }
2282+
2283+OM_uint32
2284+mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash)
2285+{
2286+ Buffer m;
2287+ OM_uint32 major;
2288+ u_int len;
2289+
2290+ buffer_init(&m);
2291+ buffer_put_string(&m, data->value, data->length);
2292+
2293+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, &m);
2294+ mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, &m);
2295+
2296+ major = buffer_get_int(&m);
2297+ hash->value = buffer_get_string(&m, &len);
2298+ hash->length = len;
2299+
2300+ buffer_free(&m);
2301+
2302+ return(major);
2303+}
2304+
2305+int
2306+mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store)
2307+{
2308+ Buffer m;
2309+ int ok;
2310+
2311+ buffer_init(&m);
2312+
2313+ buffer_put_cstring(&m, store->filename ? store->filename : "");
2314+ buffer_put_cstring(&m, store->envvar ? store->envvar : "");
2315+ buffer_put_cstring(&m, store->envval ? store->envval : "");
2316+
2317+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, &m);
2318+ mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, &m);
2319+
2320+ ok = buffer_get_int(&m);
2321+
2322+ buffer_free(&m);
2323+
2324+ return (ok);
2325+}
2326+
2327 #endif /* GSSAPI */
2328
2329diff --git a/monitor_wrap.h b/monitor_wrap.h
2330index 18c2501..a4e9d24 100644
2331--- a/monitor_wrap.h
2332+++ b/monitor_wrap.h
2333@@ -58,8 +58,10 @@ BIGNUM *mm_auth_rsa_generate_challenge(Key *);
2334 OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
2335 OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *,
2336 gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *);
2337-int mm_ssh_gssapi_userok(char *user);
2338+int mm_ssh_gssapi_userok(char *user, struct passwd *);
2339 OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
2340+OM_uint32 mm_ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
2341+int mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *);
2342 #endif
2343
2344 #ifdef USE_PAM
2345diff --git a/readconf.c b/readconf.c
2346index dc884c9..7613ff2 100644
2347--- a/readconf.c
2348+++ b/readconf.c
2349@@ -141,6 +141,8 @@ typedef enum {
2350 oClearAllForwardings, oNoHostAuthenticationForLocalhost,
2351 oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
2352 oAddressFamily, oGssAuthentication, oGssDelegateCreds,
2353+ oGssTrustDns, oGssKeyEx, oGssClientIdentity, oGssRenewalRekey,
2354+ oGssServerIdentity,
2355 oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
2356 oSendEnv, oControlPath, oControlMaster, oControlPersist,
2357 oHashKnownHosts,
2358@@ -183,10 +185,19 @@ static struct {
2359 { "afstokenpassing", oUnsupported },
2360 #if defined(GSSAPI)
2361 { "gssapiauthentication", oGssAuthentication },
2362+ { "gssapikeyexchange", oGssKeyEx },
2363 { "gssapidelegatecredentials", oGssDelegateCreds },
2364+ { "gssapitrustdns", oGssTrustDns },
2365+ { "gssapiclientidentity", oGssClientIdentity },
2366+ { "gssapiserveridentity", oGssServerIdentity },
2367+ { "gssapirenewalforcesrekey", oGssRenewalRekey },
2368 #else
2369 { "gssapiauthentication", oUnsupported },
2370+ { "gssapikeyexchange", oUnsupported },
2371 { "gssapidelegatecredentials", oUnsupported },
2372+ { "gssapitrustdns", oUnsupported },
2373+ { "gssapiclientidentity", oUnsupported },
2374+ { "gssapirenewalforcesrekey", oUnsupported },
2375 #endif
2376 { "fallbacktorsh", oDeprecated },
2377 { "usersh", oDeprecated },
2378@@ -841,10 +852,30 @@ parse_time:
2379 intptr = &options->gss_authentication;
2380 goto parse_flag;
2381
2382+ case oGssKeyEx:
2383+ intptr = &options->gss_keyex;
2384+ goto parse_flag;
2385+
2386 case oGssDelegateCreds:
2387 intptr = &options->gss_deleg_creds;
2388 goto parse_flag;
2389
2390+ case oGssTrustDns:
2391+ intptr = &options->gss_trust_dns;
2392+ goto parse_flag;
2393+
2394+ case oGssClientIdentity:
2395+ charptr = &options->gss_client_identity;
2396+ goto parse_string;
2397+
2398+ case oGssServerIdentity:
2399+ charptr = &options->gss_server_identity;
2400+ goto parse_string;
2401+
2402+ case oGssRenewalRekey:
2403+ intptr = &options->gss_renewal_rekey;
2404+ goto parse_flag;
2405+
2406 case oBatchMode:
2407 intptr = &options->batch_mode;
2408 goto parse_flag;
2409@@ -1497,7 +1528,12 @@ initialize_options(Options * options)
2410 options->pubkey_authentication = -1;
2411 options->challenge_response_authentication = -1;
2412 options->gss_authentication = -1;
2413+ options->gss_keyex = -1;
2414 options->gss_deleg_creds = -1;
2415+ options->gss_trust_dns = -1;
2416+ options->gss_renewal_rekey = -1;
2417+ options->gss_client_identity = NULL;
2418+ options->gss_server_identity = NULL;
2419 options->password_authentication = -1;
2420 options->kbd_interactive_authentication = -1;
2421 options->kbd_interactive_devices = NULL;
2422@@ -1616,8 +1652,14 @@ fill_default_options(Options * options)
2423 options->challenge_response_authentication = 1;
2424 if (options->gss_authentication == -1)
2425 options->gss_authentication = 0;
2426+ if (options->gss_keyex == -1)
2427+ options->gss_keyex = 0;
2428 if (options->gss_deleg_creds == -1)
2429 options->gss_deleg_creds = 0;
2430+ if (options->gss_trust_dns == -1)
2431+ options->gss_trust_dns = 0;
2432+ if (options->gss_renewal_rekey == -1)
2433+ options->gss_renewal_rekey = 0;
2434 if (options->password_authentication == -1)
2435 options->password_authentication = 1;
2436 if (options->kbd_interactive_authentication == -1)
2437diff --git a/readconf.h b/readconf.h
2438index 75e3f8f..5cc97f0 100644
2439--- a/readconf.h
2440+++ b/readconf.h
2441@@ -54,7 +54,12 @@ typedef struct {
2442 int challenge_response_authentication;
2443 /* Try S/Key or TIS, authentication. */
2444 int gss_authentication; /* Try GSS authentication */
2445+ int gss_keyex; /* Try GSS key exchange */
2446 int gss_deleg_creds; /* Delegate GSS credentials */
2447+ int gss_trust_dns; /* Trust DNS for GSS canonicalization */
2448+ int gss_renewal_rekey; /* Credential renewal forces rekey */
2449+ char *gss_client_identity; /* Principal to initiate GSSAPI with */
2450+ char *gss_server_identity; /* GSSAPI target principal */
2451 int password_authentication; /* Try password
2452 * authentication. */
2453 int kbd_interactive_authentication; /* Try keyboard-interactive auth. */
2454diff --git a/servconf.c b/servconf.c
2455index 7ba65d5..0083cf8 100644
2456--- a/servconf.c
2457+++ b/servconf.c
2458@@ -108,7 +108,10 @@ initialize_server_options(ServerOptions *options)
2459 options->kerberos_ticket_cleanup = -1;
2460 options->kerberos_get_afs_token = -1;
2461 options->gss_authentication=-1;
2462+ options->gss_keyex = -1;
2463 options->gss_cleanup_creds = -1;
2464+ options->gss_strict_acceptor = -1;
2465+ options->gss_store_rekey = -1;
2466 options->password_authentication = -1;
2467 options->kbd_interactive_authentication = -1;
2468 options->challenge_response_authentication = -1;
2469@@ -244,8 +247,14 @@ fill_default_server_options(ServerOptions *options)
2470 options->kerberos_get_afs_token = 0;
2471 if (options->gss_authentication == -1)
2472 options->gss_authentication = 0;
2473+ if (options->gss_keyex == -1)
2474+ options->gss_keyex = 0;
2475 if (options->gss_cleanup_creds == -1)
2476 options->gss_cleanup_creds = 1;
2477+ if (options->gss_strict_acceptor == -1)
2478+ options->gss_strict_acceptor = 1;
2479+ if (options->gss_store_rekey == -1)
2480+ options->gss_store_rekey = 0;
2481 if (options->password_authentication == -1)
2482 options->password_authentication = 1;
2483 if (options->kbd_interactive_authentication == -1)
2484@@ -340,7 +349,9 @@ typedef enum {
2485 sBanner, sUseDNS, sHostbasedAuthentication,
2486 sHostbasedUsesNameFromPacketOnly, sClientAliveInterval,
2487 sClientAliveCountMax, sAuthorizedKeysFile,
2488- sGssAuthentication, sGssCleanupCreds, sAcceptEnv, sPermitTunnel,
2489+ sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor,
2490+ sGssKeyEx, sGssStoreRekey,
2491+ sAcceptEnv, sPermitTunnel,
2492 sMatch, sPermitOpen, sForceCommand, sChrootDirectory,
2493 sUsePrivilegeSeparation, sAllowAgentForwarding,
2494 sHostCertificate,
2495@@ -407,10 +418,20 @@ static struct {
2496 #ifdef GSSAPI
2497 { "gssapiauthentication", sGssAuthentication, SSHCFG_ALL },
2498 { "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL },
2499+ { "gssapicleanupcreds", sGssCleanupCreds, SSHCFG_GLOBAL },
2500+ { "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL },
2501+ { "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL },
2502+ { "gssapistorecredentialsonrekey", sGssStoreRekey, SSHCFG_GLOBAL },
2503 #else
2504 { "gssapiauthentication", sUnsupported, SSHCFG_ALL },
2505 { "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL },
2506+ { "gssapicleanupcreds", sUnsupported, SSHCFG_GLOBAL },
2507+ { "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL },
2508+ { "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL },
2509+ { "gssapistorecredentialsonrekey", sUnsupported, SSHCFG_GLOBAL },
2510 #endif
2511+ { "gssusesessionccache", sUnsupported, SSHCFG_GLOBAL },
2512+ { "gssapiusesessioncredcache", sUnsupported, SSHCFG_GLOBAL },
2513 { "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL },
2514 { "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL },
2515 { "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL },
2516@@ -1086,10 +1107,22 @@ process_server_config_line(ServerOptions *options, char *line,
2517 intptr = &options->gss_authentication;
2518 goto parse_flag;
2519
2520+ case sGssKeyEx:
2521+ intptr = &options->gss_keyex;
2522+ goto parse_flag;
2523+
2524 case sGssCleanupCreds:
2525 intptr = &options->gss_cleanup_creds;
2526 goto parse_flag;
2527
2528+ case sGssStrictAcceptor:
2529+ intptr = &options->gss_strict_acceptor;
2530+ goto parse_flag;
2531+
2532+ case sGssStoreRekey:
2533+ intptr = &options->gss_store_rekey;
2534+ goto parse_flag;
2535+
2536 case sPasswordAuthentication:
2537 intptr = &options->password_authentication;
2538 goto parse_flag;
2539@@ -1995,7 +2028,10 @@ dump_config(ServerOptions *o)
2540 #endif
2541 #ifdef GSSAPI
2542 dump_cfg_fmtint(sGssAuthentication, o->gss_authentication);
2543+ dump_cfg_fmtint(sGssKeyEx, o->gss_keyex);
2544 dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds);
2545+ dump_cfg_fmtint(sGssStrictAcceptor, o->gss_strict_acceptor);
2546+ dump_cfg_fmtint(sGssStoreRekey, o->gss_store_rekey);
2547 #endif
2548 dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication);
2549 dump_cfg_fmtint(sKbdInteractiveAuthentication,
2550diff --git a/servconf.h b/servconf.h
2551index 752d1c5..c922eb5 100644
2552--- a/servconf.h
2553+++ b/servconf.h
2554@@ -112,7 +112,10 @@ typedef struct {
2555 int kerberos_get_afs_token; /* If true, try to get AFS token if
2556 * authenticated with Kerberos. */
2557 int gss_authentication; /* If true, permit GSSAPI authentication */
2558+ int gss_keyex; /* If true, permit GSSAPI key exchange */
2559 int gss_cleanup_creds; /* If true, destroy cred cache on logout */
2560+ int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */
2561+ int gss_store_rekey;
2562 int password_authentication; /* If true, permit password
2563 * authentication. */
2564 int kbd_interactive_authentication; /* If true, permit */
2565diff --git a/ssh-gss.h b/ssh-gss.h
2566index a99d7f0..914701b 100644
2567--- a/ssh-gss.h
2568+++ b/ssh-gss.h
2569@@ -1,6 +1,6 @@
2570 /* $OpenBSD: ssh-gss.h,v 1.11 2014/02/26 20:28:44 djm Exp $ */
2571 /*
2572- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
2573+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
2574 *
2575 * Redistribution and use in source and binary forms, with or without
2576 * modification, are permitted provided that the following conditions
2577@@ -61,10 +61,22 @@
2578
2579 #define SSH_GSS_OIDTYPE 0x06
2580
2581+#define SSH2_MSG_KEXGSS_INIT 30
2582+#define SSH2_MSG_KEXGSS_CONTINUE 31
2583+#define SSH2_MSG_KEXGSS_COMPLETE 32
2584+#define SSH2_MSG_KEXGSS_HOSTKEY 33
2585+#define SSH2_MSG_KEXGSS_ERROR 34
2586+#define SSH2_MSG_KEXGSS_GROUPREQ 40
2587+#define SSH2_MSG_KEXGSS_GROUP 41
2588+#define KEX_GSS_GRP1_SHA1_ID "gss-group1-sha1-"
2589+#define KEX_GSS_GRP14_SHA1_ID "gss-group14-sha1-"
2590+#define KEX_GSS_GEX_SHA1_ID "gss-gex-sha1-"
2591+
2592 typedef struct {
2593 char *filename;
2594 char *envvar;
2595 char *envval;
2596+ struct passwd *owner;
2597 void *data;
2598 } ssh_gssapi_ccache;
2599
2600@@ -72,8 +84,11 @@ typedef struct {
2601 gss_buffer_desc displayname;
2602 gss_buffer_desc exportedname;
2603 gss_cred_id_t creds;
2604+ gss_name_t name;
2605 struct ssh_gssapi_mech_struct *mech;
2606 ssh_gssapi_ccache store;
2607+ int used;
2608+ int updated;
2609 } ssh_gssapi_client;
2610
2611 typedef struct ssh_gssapi_mech_struct {
2612@@ -84,6 +99,7 @@ typedef struct ssh_gssapi_mech_struct {
2613 int (*userok) (ssh_gssapi_client *, char *);
2614 int (*localname) (ssh_gssapi_client *, char **);
2615 void (*storecreds) (ssh_gssapi_client *);
2616+ int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *);
2617 } ssh_gssapi_mech;
2618
2619 typedef struct {
2620@@ -94,10 +110,11 @@ typedef struct {
2621 gss_OID oid; /* client */
2622 gss_cred_id_t creds; /* server */
2623 gss_name_t client; /* server */
2624- gss_cred_id_t client_creds; /* server */
2625+ gss_cred_id_t client_creds; /* both */
2626 } Gssctxt;
2627
2628 extern ssh_gssapi_mech *supported_mechs[];
2629+extern Gssctxt *gss_kex_context;
2630
2631 int ssh_gssapi_check_oid(Gssctxt *, void *, size_t);
2632 void ssh_gssapi_set_oid_data(Gssctxt *, void *, size_t);
2633@@ -119,16 +136,32 @@ void ssh_gssapi_build_ctx(Gssctxt **);
2634 void ssh_gssapi_delete_ctx(Gssctxt **);
2635 OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
2636 void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *);
2637-int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *);
2638+int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *, const char *);
2639+OM_uint32 ssh_gssapi_client_identity(Gssctxt *, const char *);
2640+int ssh_gssapi_credentials_updated(Gssctxt *);
2641
2642 /* In the server */
2643+typedef int ssh_gssapi_check_fn(Gssctxt **, gss_OID, const char *,
2644+ const char *);
2645+char *ssh_gssapi_client_mechanisms(const char *, const char *);
2646+char *ssh_gssapi_kex_mechs(gss_OID_set, ssh_gssapi_check_fn *, const char *,
2647+ const char *);
2648+gss_OID ssh_gssapi_id_kex(Gssctxt *, char *, int);
2649+int ssh_gssapi_server_check_mech(Gssctxt **,gss_OID, const char *,
2650+ const char *);
2651 OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
2652-int ssh_gssapi_userok(char *name);
2653+int ssh_gssapi_userok(char *name, struct passwd *);
2654 OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
2655 void ssh_gssapi_do_child(char ***, u_int *);
2656 void ssh_gssapi_cleanup_creds(void);
2657 void ssh_gssapi_storecreds(void);
2658
2659+char *ssh_gssapi_server_mechanisms(void);
2660+int ssh_gssapi_oid_table_ok(void);
2661+
2662+int ssh_gssapi_update_creds(ssh_gssapi_ccache *store);
2663+void ssh_gssapi_rekey_creds(void);
2664+
2665 #endif /* GSSAPI */
2666
2667 #endif /* _SSH_GSS_H */
2668diff --git a/ssh_config b/ssh_config
2669index 03a228f..228e5ab 100644
2670--- a/ssh_config
2671+++ b/ssh_config
2672@@ -26,6 +26,8 @@
2673 # HostbasedAuthentication no
2674 # GSSAPIAuthentication no
2675 # GSSAPIDelegateCredentials no
2676+# GSSAPIKeyExchange no
2677+# GSSAPITrustDNS no
2678 # BatchMode no
2679 # CheckHostIP yes
2680 # AddressFamily any
2681diff --git a/ssh_config.5 b/ssh_config.5
2682index b580392..e7accd6 100644
2683--- a/ssh_config.5
2684+++ b/ssh_config.5
2685@@ -682,11 +682,43 @@ Specifies whether user authentication based on GSSAPI is allowed.
2686 The default is
2687 .Dq no .
2688 Note that this option applies to protocol version 2 only.
2689+.It Cm GSSAPIKeyExchange
2690+Specifies whether key exchange based on GSSAPI may be used. When using
2691+GSSAPI key exchange the server need not have a host key.
2692+The default is
2693+.Dq no .
2694+Note that this option applies to protocol version 2 only.
2695+.It Cm GSSAPIClientIdentity
2696+If set, specifies the GSSAPI client identity that ssh should use when
2697+connecting to the server. The default is unset, which means that the default
2698+identity will be used.
2699+.It Cm GSSAPIServerIdentity
2700+If set, specifies the GSSAPI server identity that ssh should expect when
2701+connecting to the server. The default is unset, which means that the
2702+expected GSSAPI server identity will be determined from the target
2703+hostname.
2704 .It Cm GSSAPIDelegateCredentials
2705 Forward (delegate) credentials to the server.
2706 The default is
2707 .Dq no .
2708-Note that this option applies to protocol version 2 only.
2709+Note that this option applies to protocol version 2 connections using GSSAPI.
2710+.It Cm GSSAPIRenewalForcesRekey
2711+If set to
2712+.Dq yes
2713+then renewal of the client's GSSAPI credentials will force the rekeying of the
2714+ssh connection. With a compatible server, this can delegate the renewed
2715+credentials to a session on the server.
2716+The default is
2717+.Dq no .
2718+.It Cm GSSAPITrustDns
2719+Set to
2720+.Dq yes to indicate that the DNS is trusted to securely canonicalize
2721+the name of the host being connected to. If
2722+.Dq no, the hostname entered on the
2723+command line will be passed untouched to the GSSAPI library.
2724+The default is
2725+.Dq no .
2726+This option only applies to protocol version 2 connections using GSSAPI.
2727 .It Cm HashKnownHosts
2728 Indicates that
2729 .Xr ssh 1
2730diff --git a/sshconnect2.c b/sshconnect2.c
2731index 7f4ff41..66cb035 100644
2732--- a/sshconnect2.c
2733+++ b/sshconnect2.c
2734@@ -158,9 +158,34 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
2735 {
2736 Kex *kex;
2737
2738+#ifdef GSSAPI
2739+ char *orig = NULL, *gss = NULL;
2740+ char *gss_host = NULL;
2741+#endif
2742+
2743 xxx_host = host;
2744 xxx_hostaddr = hostaddr;
2745
2746+#ifdef GSSAPI
2747+ if (options.gss_keyex) {
2748+ /* Add the GSSAPI mechanisms currently supported on this
2749+ * client to the key exchange algorithm proposal */
2750+ orig = myproposal[PROPOSAL_KEX_ALGS];
2751+
2752+ if (options.gss_trust_dns)
2753+ gss_host = (char *)get_canonical_hostname(1);
2754+ else
2755+ gss_host = host;
2756+
2757+ gss = ssh_gssapi_client_mechanisms(gss_host, options.gss_client_identity);
2758+ if (gss) {
2759+ debug("Offering GSSAPI proposal: %s", gss);
2760+ xasprintf(&myproposal[PROPOSAL_KEX_ALGS],
2761+ "%s,%s", gss, orig);
2762+ }
2763+ }
2764+#endif
2765+
2766 if (options.ciphers == (char *)-1) {
2767 logit("No valid ciphers for protocol version 2 given, using defaults.");
2768 options.ciphers = NULL;
2769@@ -196,6 +221,17 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
2770 if (options.kex_algorithms != NULL)
2771 myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
2772
2773+#ifdef GSSAPI
2774+ /* If we've got GSSAPI algorithms, then we also support the
2775+ * 'null' hostkey, as a last resort */
2776+ if (options.gss_keyex && gss) {
2777+ orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
2778+ xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],
2779+ "%s,null", orig);
2780+ free(gss);
2781+ }
2782+#endif
2783+
2784 if (options.rekey_limit || options.rekey_interval)
2785 packet_set_rekey_limits((u_int32_t)options.rekey_limit,
2786 (time_t)options.rekey_interval);
2787@@ -208,10 +244,30 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
2788 kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
2789 kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
2790 kex->kex[KEX_C25519_SHA256] = kexc25519_client;
2791+#ifdef GSSAPI
2792+ if (options.gss_keyex) {
2793+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client;
2794+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client;
2795+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client;
2796+ }
2797+#endif
2798 kex->client_version_string=client_version_string;
2799 kex->server_version_string=server_version_string;
2800 kex->verify_host_key=&verify_host_key_callback;
2801
2802+#ifdef GSSAPI
2803+ if (options.gss_keyex) {
2804+ kex->gss_deleg_creds = options.gss_deleg_creds;
2805+ kex->gss_trust_dns = options.gss_trust_dns;
2806+ kex->gss_client = options.gss_client_identity;
2807+ if (options.gss_server_identity) {
2808+ kex->gss_host = options.gss_server_identity;
2809+ } else {
2810+ kex->gss_host = gss_host;
2811+ }
2812+ }
2813+#endif
2814+
2815 xxx_kex = kex;
2816
2817 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
2818@@ -301,6 +357,7 @@ void input_gssapi_token(int type, u_int32_t, void *);
2819 void input_gssapi_hash(int type, u_int32_t, void *);
2820 void input_gssapi_error(int, u_int32_t, void *);
2821 void input_gssapi_errtok(int, u_int32_t, void *);
2822+int userauth_gsskeyex(Authctxt *authctxt);
2823 #endif
2824
2825 void userauth(Authctxt *, char *);
2826@@ -316,6 +373,11 @@ static char *authmethods_get(void);
2827
2828 Authmethod authmethods[] = {
2829 #ifdef GSSAPI
2830+ {"gssapi-keyex",
2831+ userauth_gsskeyex,
2832+ NULL,
2833+ &options.gss_authentication,
2834+ NULL},
2835 {"gssapi-with-mic",
2836 userauth_gssapi,
2837 NULL,
2838@@ -612,19 +674,31 @@ userauth_gssapi(Authctxt *authctxt)
2839 static u_int mech = 0;
2840 OM_uint32 min;
2841 int ok = 0;
2842+ const char *gss_host;
2843+
2844+ if (options.gss_server_identity)
2845+ gss_host = options.gss_server_identity;
2846+ else if (options.gss_trust_dns)
2847+ gss_host = get_canonical_hostname(1);
2848+ else
2849+ gss_host = authctxt->host;
2850
2851 /* Try one GSSAPI method at a time, rather than sending them all at
2852 * once. */
2853
2854 if (gss_supported == NULL)
2855- gss_indicate_mechs(&min, &gss_supported);
2856+ if (GSS_ERROR(gss_indicate_mechs(&min, &gss_supported))) {
2857+ gss_supported = NULL;
2858+ return 0;
2859+ }
2860
2861 /* Check to see if the mechanism is usable before we offer it */
2862 while (mech < gss_supported->count && !ok) {
2863 /* My DER encoding requires length<128 */
2864 if (gss_supported->elements[mech].length < 128 &&
2865 ssh_gssapi_check_mechanism(&gssctxt,
2866- &gss_supported->elements[mech], authctxt->host)) {
2867+ &gss_supported->elements[mech], gss_host,
2868+ options.gss_client_identity)) {
2869 ok = 1; /* Mechanism works */
2870 } else {
2871 mech++;
2872@@ -721,8 +795,8 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt)
2873 {
2874 Authctxt *authctxt = ctxt;
2875 Gssctxt *gssctxt;
2876- int oidlen;
2877- char *oidv;
2878+ u_int oidlen;
2879+ u_char *oidv;
2880
2881 if (authctxt == NULL)
2882 fatal("input_gssapi_response: no authentication context");
2883@@ -831,6 +905,48 @@ input_gssapi_error(int type, u_int32_t plen, void *ctxt)
2884 free(msg);
2885 free(lang);
2886 }
2887+
2888+int
2889+userauth_gsskeyex(Authctxt *authctxt)
2890+{
2891+ Buffer b;
2892+ gss_buffer_desc gssbuf;
2893+ gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
2894+ OM_uint32 ms;
2895+
2896+ static int attempt = 0;
2897+ if (attempt++ >= 1)
2898+ return (0);
2899+
2900+ if (gss_kex_context == NULL) {
2901+ debug("No valid Key exchange context");
2902+ return (0);
2903+ }
2904+
2905+ ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service,
2906+ "gssapi-keyex");
2907+
2908+ gssbuf.value = buffer_ptr(&b);
2909+ gssbuf.length = buffer_len(&b);
2910+
2911+ if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) {
2912+ buffer_free(&b);
2913+ return (0);
2914+ }
2915+
2916+ packet_start(SSH2_MSG_USERAUTH_REQUEST);
2917+ packet_put_cstring(authctxt->server_user);
2918+ packet_put_cstring(authctxt->service);
2919+ packet_put_cstring(authctxt->method->name);
2920+ packet_put_string(mic.value, mic.length);
2921+ packet_send();
2922+
2923+ buffer_free(&b);
2924+ gss_release_buffer(&ms, &mic);
2925+
2926+ return (1);
2927+}
2928+
2929 #endif /* GSSAPI */
2930
2931 int
2932diff --git a/sshd.c b/sshd.c
2933index 7523de9..d787fea 100644
2934--- a/sshd.c
2935+++ b/sshd.c
2936@@ -122,6 +122,10 @@
2937 #include "ssh-sandbox.h"
2938 #include "version.h"
2939
2940+#ifdef USE_SECURITY_SESSION_API
2941+#include <Security/AuthSession.h>
2942+#endif
2943+
2944 #ifdef LIBWRAP
2945 #include <tcpd.h>
2946 #include <syslog.h>
2947@@ -1728,10 +1732,13 @@ main(int ac, char **av)
2948 logit("Disabling protocol version 1. Could not load host key");
2949 options.protocol &= ~SSH_PROTO_1;
2950 }
2951+#ifndef GSSAPI
2952+ /* The GSSAPI key exchange can run without a host key */
2953 if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
2954 logit("Disabling protocol version 2. Could not load host key");
2955 options.protocol &= ~SSH_PROTO_2;
2956 }
2957+#endif
2958 if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
2959 logit("sshd: no hostkeys available -- exiting.");
2960 exit(1);
2961@@ -2058,6 +2065,60 @@ main(int ac, char **av)
2962 remote_ip, remote_port,
2963 get_local_ipaddr(sock_in), get_local_port());
2964
2965+#ifdef USE_SECURITY_SESSION_API
2966+ /*
2967+ * Create a new security session for use by the new user login if
2968+ * the current session is the root session or we are not launched
2969+ * by inetd (eg: debugging mode or server mode). We do not
2970+ * necessarily need to create a session if we are launched from
2971+ * inetd because Panther xinetd will create a session for us.
2972+ *
2973+ * The only case where this logic will fail is if there is an
2974+ * inetd running in a non-root session which is not creating
2975+ * new sessions for us. Then all the users will end up in the
2976+ * same session (bad).
2977+ *
2978+ * When the client exits, the session will be destroyed for us
2979+ * automatically.
2980+ *
2981+ * We must create the session before any credentials are stored
2982+ * (including AFS pags, which happens a few lines below).
2983+ */
2984+ {
2985+ OSStatus err = 0;
2986+ SecuritySessionId sid = 0;
2987+ SessionAttributeBits sattrs = 0;
2988+
2989+ err = SessionGetInfo(callerSecuritySession, &sid, &sattrs);
2990+ if (err)
2991+ error("SessionGetInfo() failed with error %.8X",
2992+ (unsigned) err);
2993+ else
2994+ debug("Current Session ID is %.8X / Session Attributes are %.8X",
2995+ (unsigned) sid, (unsigned) sattrs);
2996+
2997+ if (inetd_flag && !(sattrs & sessionIsRoot))
2998+ debug("Running in inetd mode in a non-root session... "
2999+ "assuming inetd created the session for us.");
3000+ else {
3001+ debug("Creating new security session...");
3002+ err = SessionCreate(0, sessionHasTTY | sessionIsRemote);
3003+ if (err)
3004+ error("SessionCreate() failed with error %.8X",
3005+ (unsigned) err);
3006+
3007+ err = SessionGetInfo(callerSecuritySession, &sid,
3008+ &sattrs);
3009+ if (err)
3010+ error("SessionGetInfo() failed with error %.8X",
3011+ (unsigned) err);
3012+ else
3013+ debug("New Session ID is %.8X / Session Attributes are %.8X",
3014+ (unsigned) sid, (unsigned) sattrs);
3015+ }
3016+ }
3017+#endif
3018+
3019 /*
3020 * We don't want to listen forever unless the other side
3021 * successfully authenticates itself. So we set up an alarm which is
3022@@ -2469,6 +2530,48 @@ do_ssh2_kex(void)
3023 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
3024 list_hostkey_types());
3025
3026+#ifdef GSSAPI
3027+ {
3028+ char *orig;
3029+ char *gss = NULL;
3030+ char *newstr = NULL;
3031+ orig = myproposal[PROPOSAL_KEX_ALGS];
3032+
3033+ /*
3034+ * If we don't have a host key, then there's no point advertising
3035+ * the other key exchange algorithms
3036+ */
3037+
3038+ if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0)
3039+ orig = NULL;
3040+
3041+ if (options.gss_keyex)
3042+ gss = ssh_gssapi_server_mechanisms();
3043+ else
3044+ gss = NULL;
3045+
3046+ if (gss && orig)
3047+ xasprintf(&newstr, "%s,%s", gss, orig);
3048+ else if (gss)
3049+ newstr = gss;
3050+ else if (orig)
3051+ newstr = orig;
3052+
3053+ /*
3054+ * If we've got GSSAPI mechanisms, then we've got the 'null' host
3055+ * key alg, but we can't tell people about it unless its the only
3056+ * host key algorithm we support
3057+ */
3058+ if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0)
3059+ myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null";
3060+
3061+ if (newstr)
3062+ myproposal[PROPOSAL_KEX_ALGS] = newstr;
3063+ else
3064+ fatal("No supported key exchange algorithms");
3065+ }
3066+#endif
3067+
3068 /* start key exchange */
3069 kex = kex_setup(myproposal);
3070 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
3071@@ -2477,6 +2580,13 @@ do_ssh2_kex(void)
3072 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
3073 kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
3074 kex->kex[KEX_C25519_SHA256] = kexc25519_server;
3075+#ifdef GSSAPI
3076+ if (options.gss_keyex) {
3077+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
3078+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
3079+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
3080+ }
3081+#endif
3082 kex->server = 1;
3083 kex->client_version_string=client_version_string;
3084 kex->server_version_string=server_version_string;
3085diff --git a/sshd_config b/sshd_config
3086index e9045bc..d9b8594 100644
3087--- a/sshd_config
3088+++ b/sshd_config
3089@@ -84,6 +84,8 @@ AuthorizedKeysFile .ssh/authorized_keys
3090 # GSSAPI options
3091 #GSSAPIAuthentication no
3092 #GSSAPICleanupCredentials yes
3093+#GSSAPIStrictAcceptorCheck yes
3094+#GSSAPIKeyExchange no
3095
3096 # Set this to 'yes' to enable PAM authentication, account processing,
3097 # and session processing. If this is enabled, PAM authentication will
3098diff --git a/sshd_config.5 b/sshd_config.5
3099index ce71efe..ceed88a 100644
3100--- a/sshd_config.5
3101+++ b/sshd_config.5
3102@@ -493,12 +493,40 @@ Specifies whether user authentication based on GSSAPI is allowed.
3103 The default is
3104 .Dq no .
3105 Note that this option applies to protocol version 2 only.
3106+.It Cm GSSAPIKeyExchange
3107+Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange
3108+doesn't rely on ssh keys to verify host identity.
3109+The default is
3110+.Dq no .
3111+Note that this option applies to protocol version 2 only.
3112 .It Cm GSSAPICleanupCredentials
3113 Specifies whether to automatically destroy the user's credentials cache
3114 on logout.
3115 The default is
3116 .Dq yes .
3117 Note that this option applies to protocol version 2 only.
3118+.It Cm GSSAPIStrictAcceptorCheck
3119+Determines whether to be strict about the identity of the GSSAPI acceptor
3120+a client authenticates against. If
3121+.Dq yes
3122+then the client must authenticate against the
3123+.Pa host
3124+service on the current hostname. If
3125+.Dq no
3126+then the client may authenticate against any service key stored in the
3127+machine's default store. This facility is provided to assist with operation
3128+on multi homed machines.
3129+The default is
3130+.Dq yes .
3131+Note that this option applies only to protocol version 2 GSSAPI connections,
3132+and setting it to
3133+.Dq no
3134+may only work with recent Kerberos GSSAPI libraries.
3135+.It Cm GSSAPIStoreCredentialsOnRekey
3136+Controls whether the user's GSSAPI credentials should be updated following a
3137+successful connection rekeying. This option can be used to accepted renewed
3138+or updated credentials from a compatible client. The default is
3139+.Dq no .
3140 .It Cm HostbasedAuthentication
3141 Specifies whether rhosts or /etc/hosts.equiv authentication together
3142 with successful public key client host authentication is allowed
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 09:14:13 +0000