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-rw-r--r--debian/patches/gssapi.patch3298
1 files changed, 3298 insertions, 0 deletions
diff --git a/debian/patches/gssapi.patch b/debian/patches/gssapi.patch
new file mode 100644
index 000000000..deddbcb80
--- /dev/null
+++ b/debian/patches/gssapi.patch
@@ -0,0 +1,3298 @@
1From d51c7ac3328464dec21514fb398ab5c140a0664f 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: 2017-01-16
21
22Patch-Name: gssapi.patch
23---
24 ChangeLog.gssapi | 113 +++++++++++++++++++
25 Makefile.in | 3 +-
26 auth-krb5.c | 17 ++-
27 auth.c | 96 +---------------
28 auth2-gss.c | 48 +++++++-
29 auth2.c | 2 +
30 canohost.c | 93 +++++++++++++++
31 canohost.h | 3 +
32 clientloop.c | 15 ++-
33 config.h.in | 6 +
34 configure.ac | 24 ++++
35 gss-genr.c | 275 +++++++++++++++++++++++++++++++++++++++++++-
36 gss-serv-krb5.c | 85 ++++++++++++--
37 gss-serv.c | 184 +++++++++++++++++++++++++++---
38 kex.c | 19 ++++
39 kex.h | 14 +++
40 kexgssc.c | 338 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
41 kexgsss.c | 295 ++++++++++++++++++++++++++++++++++++++++++++++++
42 monitor.c | 115 +++++++++++++++++--
43 monitor.h | 3 +
44 monitor_wrap.c | 47 +++++++-
45 monitor_wrap.h | 4 +-
46 readconf.c | 43 +++++++
47 readconf.h | 5 +
48 servconf.c | 26 +++++
49 servconf.h | 2 +
50 ssh-gss.h | 41 ++++++-
51 ssh_config | 2 +
52 ssh_config.5 | 32 ++++++
53 sshconnect2.c | 131 ++++++++++++++++++++-
54 sshd.c | 112 +++++++++++++++++-
55 sshd_config | 2 +
56 sshd_config.5 | 10 ++
57 sshkey.c | 3 +-
58 sshkey.h | 1 +
59 35 files changed, 2062 insertions(+), 147 deletions(-)
60 create mode 100644 ChangeLog.gssapi
61 create mode 100644 kexgssc.c
62 create mode 100644 kexgsss.c
63
64diff --git a/ChangeLog.gssapi b/ChangeLog.gssapi
65new file mode 100644
66index 00000000..f117a336
67--- /dev/null
68+++ b/ChangeLog.gssapi
69@@ -0,0 +1,113 @@
70+20110101
71+ - Finally update for OpenSSH 5.6p1
72+ - Add GSSAPIServerIdentity option from Jim Basney
73+
74+20100308
75+ - [ Makefile.in, key.c, key.h ]
76+ Updates for OpenSSH 5.4p1
77+ - [ servconf.c ]
78+ Include GSSAPI options in the sshd -T configuration dump, and flag
79+ some older configuration options as being unsupported. Thanks to Colin
80+ Watson.
81+ -
82+
83+20100124
84+ - [ sshconnect2.c ]
85+ Adapt to deal with additional element in Authmethod structure. Thanks to
86+ Colin Watson
87+
88+20090615
89+ - [ gss-genr.c gss-serv.c kexgssc.c kexgsss.c monitor.c sshconnect2.c
90+ sshd.c ]
91+ Fix issues identified by Greg Hudson following a code review
92+ Check return value of gss_indicate_mechs
93+ Protect GSSAPI calls in monitor, so they can only be used if enabled
94+ Check return values of bignum functions in key exchange
95+ Use BN_clear_free to clear other side's DH value
96+ Make ssh_gssapi_id_kex more robust
97+ Only configure kex table pointers if GSSAPI is enabled
98+ Don't leak mechanism list, or gss mechanism list
99+ Cast data.length before printing
100+ If serverkey isn't provided, use an empty string, rather than NULL
101+
102+20090201
103+ - [ gss-genr.c gss-serv.c kex.h kexgssc.c readconf.c readconf.h ssh-gss.h
104+ ssh_config.5 sshconnet2.c ]
105+ Add support for the GSSAPIClientIdentity option, which allows the user
106+ to specify which GSSAPI identity to use to contact a given server
107+
108+20080404
109+ - [ gss-serv.c ]
110+ Add code to actually implement GSSAPIStrictAcceptCheck, which had somehow
111+ been omitted from a previous version of this patch. Reported by Borislav
112+ Stoichkov
113+
114+20070317
115+ - [ gss-serv-krb5.c ]
116+ Remove C99ism, where new_ccname was being declared in the middle of a
117+ function
118+
119+20061220
120+ - [ servconf.c ]
121+ Make default for GSSAPIStrictAcceptorCheck be Yes, to match previous, and
122+ documented, behaviour. Reported by Dan Watson.
123+
124+20060910
125+ - [ gss-genr.c kexgssc.c kexgsss.c kex.h monitor.c sshconnect2.c sshd.c
126+ ssh-gss.h ]
127+ add support for gss-group14-sha1 key exchange mechanisms
128+ - [ gss-serv.c servconf.c servconf.h sshd_config sshd_config.5 ]
129+ Add GSSAPIStrictAcceptorCheck option to allow the disabling of
130+ acceptor principal checking on multi-homed machines.
131+ <Bugzilla #928>
132+ - [ sshd_config ssh_config ]
133+ Add settings for GSSAPIKeyExchange and GSSAPITrustDNS to the sample
134+ configuration files
135+ - [ kexgss.c kegsss.c sshconnect2.c sshd.c ]
136+ Code cleanup. Replace strlen/xmalloc/snprintf sequences with xasprintf()
137+ Limit length of error messages displayed by client
138+
139+20060909
140+ - [ gss-genr.c gss-serv.c ]
141+ move ssh_gssapi_acquire_cred() and ssh_gssapi_server_ctx to be server
142+ only, where they belong
143+ <Bugzilla #1225>
144+
145+20060829
146+ - [ gss-serv-krb5.c ]
147+ Fix CCAPI credentials cache name when creating KRB5CCNAME environment
148+ variable
149+
150+20060828
151+ - [ gss-genr.c ]
152+ Avoid Heimdal context freeing problem
153+ <Fixed upstream 20060829>
154+
155+20060818
156+ - [ gss-genr.c ssh-gss.h sshconnect2.c ]
157+ Make sure that SPENGO is disabled
158+ <Bugzilla #1218 - Fixed upstream 20060818>
159+
160+20060421
161+ - [ gssgenr.c, sshconnect2.c ]
162+ a few type changes (signed versus unsigned, int versus size_t) to
163+ fix compiler errors/warnings
164+ (from jbasney AT ncsa.uiuc.edu)
165+ - [ kexgssc.c, sshconnect2.c ]
166+ fix uninitialized variable warnings
167+ (from jbasney AT ncsa.uiuc.edu)
168+ - [ gssgenr.c ]
169+ pass oid to gss_display_status (helpful when using GSSAPI mechglue)
170+ (from jbasney AT ncsa.uiuc.edu)
171+ <Bugzilla #1220 >
172+ - [ gss-serv-krb5.c ]
173+ #ifdef HAVE_GSSAPI_KRB5 should be #ifdef HAVE_GSSAPI_KRB5_H
174+ (from jbasney AT ncsa.uiuc.edu)
175+ <Fixed upstream 20060304>
176+ - [ readconf.c, readconf.h, ssh_config.5, sshconnect2.c
177+ add client-side GssapiKeyExchange option
178+ (from jbasney AT ncsa.uiuc.edu)
179+ - [ sshconnect2.c ]
180+ add support for GssapiTrustDns option for gssapi-with-mic
181+ (from jbasney AT ncsa.uiuc.edu)
182+ <gssapi-with-mic support is Bugzilla #1008>
183diff --git a/Makefile.in b/Makefile.in
184index 5870e9e6..6b774c1a 100644
185--- a/Makefile.in
186+++ b/Makefile.in
187@@ -92,6 +92,7 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
188 kex.o kexdh.o kexgex.o kexecdh.o kexc25519.o \
189 kexdhc.o kexgexc.o kexecdhc.o kexc25519c.o \
190 kexdhs.o kexgexs.o kexecdhs.o kexc25519s.o \
191+ kexgssc.o \
192 platform-pledge.o platform-tracing.o
193
194 SSHOBJS= ssh.o readconf.o clientloop.o sshtty.o \
195@@ -105,7 +106,7 @@ SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o \
196 auth-skey.o auth-bsdauth.o auth2-hostbased.o auth2-kbdint.o \
197 auth2-none.o auth2-passwd.o auth2-pubkey.o \
198 monitor.o monitor_wrap.o auth-krb5.o \
199- auth2-gss.o gss-serv.o gss-serv-krb5.o \
200+ auth2-gss.o gss-serv.o gss-serv-krb5.o kexgsss.o \
201 loginrec.o auth-pam.o auth-shadow.o auth-sia.o md5crypt.o \
202 sftp-server.o sftp-common.o \
203 sandbox-null.o sandbox-rlimit.o sandbox-systrace.o sandbox-darwin.o \
204diff --git a/auth-krb5.c b/auth-krb5.c
205index a5a81ed2..38e7fee2 100644
206--- a/auth-krb5.c
207+++ b/auth-krb5.c
208@@ -182,8 +182,13 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
209
210 len = strlen(authctxt->krb5_ticket_file) + 6;
211 authctxt->krb5_ccname = xmalloc(len);
212+#ifdef USE_CCAPI
213+ snprintf(authctxt->krb5_ccname, len, "API:%s",
214+ authctxt->krb5_ticket_file);
215+#else
216 snprintf(authctxt->krb5_ccname, len, "FILE:%s",
217 authctxt->krb5_ticket_file);
218+#endif
219
220 #ifdef USE_PAM
221 if (options.use_pam)
222@@ -240,15 +245,22 @@ krb5_cleanup_proc(Authctxt *authctxt)
223 #ifndef HEIMDAL
224 krb5_error_code
225 ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
226- int tmpfd, ret, oerrno;
227+ int ret, oerrno;
228 char ccname[40];
229 mode_t old_umask;
230+#ifdef USE_CCAPI
231+ char cctemplate[] = "API:krb5cc_%d";
232+#else
233+ char cctemplate[] = "FILE:/tmp/krb5cc_%d_XXXXXXXXXX";
234+ int tmpfd;
235+#endif
236
237 ret = snprintf(ccname, sizeof(ccname),
238- "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
239+ cctemplate, geteuid());
240 if (ret < 0 || (size_t)ret >= sizeof(ccname))
241 return ENOMEM;
242
243+#ifndef USE_CCAPI
244 old_umask = umask(0177);
245 tmpfd = mkstemp(ccname + strlen("FILE:"));
246 oerrno = errno;
247@@ -265,6 +277,7 @@ ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
248 return oerrno;
249 }
250 close(tmpfd);
251+#endif
252
253 return (krb5_cc_resolve(ctx, ccname, ccache));
254 }
255diff --git a/auth.c b/auth.c
256index 6ee6116d..c6390687 100644
257--- a/auth.c
258+++ b/auth.c
259@@ -372,7 +372,8 @@ auth_root_allowed(const char *method)
260 case PERMIT_NO_PASSWD:
261 if (strcmp(method, "publickey") == 0 ||
262 strcmp(method, "hostbased") == 0 ||
263- strcmp(method, "gssapi-with-mic") == 0)
264+ strcmp(method, "gssapi-with-mic") == 0 ||
265+ strcmp(method, "gssapi-keyex") == 0)
266 return 1;
267 break;
268 case PERMIT_FORCED_ONLY:
269@@ -794,99 +795,6 @@ fakepw(void)
270 return (&fake);
271 }
272
273-/*
274- * Returns the remote DNS hostname as a string. The returned string must not
275- * be freed. NB. this will usually trigger a DNS query the first time it is
276- * called.
277- * This function does additional checks on the hostname to mitigate some
278- * attacks on legacy rhosts-style authentication.
279- * XXX is RhostsRSAAuthentication vulnerable to these?
280- * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?)
281- */
282-
283-static char *
284-remote_hostname(struct ssh *ssh)
285-{
286- struct sockaddr_storage from;
287- socklen_t fromlen;
288- struct addrinfo hints, *ai, *aitop;
289- char name[NI_MAXHOST], ntop2[NI_MAXHOST];
290- const char *ntop = ssh_remote_ipaddr(ssh);
291-
292- /* Get IP address of client. */
293- fromlen = sizeof(from);
294- memset(&from, 0, sizeof(from));
295- if (getpeername(ssh_packet_get_connection_in(ssh),
296- (struct sockaddr *)&from, &fromlen) < 0) {
297- debug("getpeername failed: %.100s", strerror(errno));
298- return strdup(ntop);
299- }
300-
301- ipv64_normalise_mapped(&from, &fromlen);
302- if (from.ss_family == AF_INET6)
303- fromlen = sizeof(struct sockaddr_in6);
304-
305- debug3("Trying to reverse map address %.100s.", ntop);
306- /* Map the IP address to a host name. */
307- if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name),
308- NULL, 0, NI_NAMEREQD) != 0) {
309- /* Host name not found. Use ip address. */
310- return strdup(ntop);
311- }
312-
313- /*
314- * if reverse lookup result looks like a numeric hostname,
315- * someone is trying to trick us by PTR record like following:
316- * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5
317- */
318- memset(&hints, 0, sizeof(hints));
319- hints.ai_socktype = SOCK_DGRAM; /*dummy*/
320- hints.ai_flags = AI_NUMERICHOST;
321- if (getaddrinfo(name, NULL, &hints, &ai) == 0) {
322- logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
323- name, ntop);
324- freeaddrinfo(ai);
325- return strdup(ntop);
326- }
327-
328- /* Names are stored in lowercase. */
329- lowercase(name);
330-
331- /*
332- * Map it back to an IP address and check that the given
333- * address actually is an address of this host. This is
334- * necessary because anyone with access to a name server can
335- * define arbitrary names for an IP address. Mapping from
336- * name to IP address can be trusted better (but can still be
337- * fooled if the intruder has access to the name server of
338- * the domain).
339- */
340- memset(&hints, 0, sizeof(hints));
341- hints.ai_family = from.ss_family;
342- hints.ai_socktype = SOCK_STREAM;
343- if (getaddrinfo(name, NULL, &hints, &aitop) != 0) {
344- logit("reverse mapping checking getaddrinfo for %.700s "
345- "[%s] failed.", name, ntop);
346- return strdup(ntop);
347- }
348- /* Look for the address from the list of addresses. */
349- for (ai = aitop; ai; ai = ai->ai_next) {
350- if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2,
351- sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 &&
352- (strcmp(ntop, ntop2) == 0))
353- break;
354- }
355- freeaddrinfo(aitop);
356- /* If we reached the end of the list, the address was not there. */
357- if (ai == NULL) {
358- /* Address not found for the host name. */
359- logit("Address %.100s maps to %.600s, but this does not "
360- "map back to the address.", ntop, name);
361- return strdup(ntop);
362- }
363- return strdup(name);
364-}
365-
366 /*
367 * Return the canonical name of the host in the other side of the current
368 * connection. The host name is cached, so it is efficient to call this
369diff --git a/auth2-gss.c b/auth2-gss.c
370index 1ca83577..3b5036df 100644
371--- a/auth2-gss.c
372+++ b/auth2-gss.c
373@@ -1,7 +1,7 @@
374 /* $OpenBSD: auth2-gss.c,v 1.22 2015/01/19 20:07:45 markus Exp $ */
375
376 /*
377- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
378+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
379 *
380 * Redistribution and use in source and binary forms, with or without
381 * modification, are permitted provided that the following conditions
382@@ -53,6 +53,40 @@ static int input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
383 static int input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
384 static int input_gssapi_errtok(int, u_int32_t, void *);
385
386+/*
387+ * The 'gssapi_keyex' userauth mechanism.
388+ */
389+static int
390+userauth_gsskeyex(Authctxt *authctxt)
391+{
392+ int authenticated = 0;
393+ Buffer b;
394+ gss_buffer_desc mic, gssbuf;
395+ u_int len;
396+
397+ mic.value = packet_get_string(&len);
398+ mic.length = len;
399+
400+ packet_check_eom();
401+
402+ ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
403+ "gssapi-keyex");
404+
405+ gssbuf.value = buffer_ptr(&b);
406+ gssbuf.length = buffer_len(&b);
407+
408+ /* gss_kex_context is NULL with privsep, so we can't check it here */
409+ if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context,
410+ &gssbuf, &mic))))
411+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
412+ authctxt->pw));
413+
414+ buffer_free(&b);
415+ free(mic.value);
416+
417+ return (authenticated);
418+}
419+
420 /*
421 * We only support those mechanisms that we know about (ie ones that we know
422 * how to check local user kuserok and the like)
423@@ -238,7 +272,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
424
425 packet_check_eom();
426
427- authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
428+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
429+ authctxt->pw));
430
431 authctxt->postponed = 0;
432 dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
433@@ -274,7 +309,8 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
434 gssbuf.length = buffer_len(&b);
435
436 if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
437- authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
438+ authenticated =
439+ PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw));
440 else
441 logit("GSSAPI MIC check failed");
442
443@@ -290,6 +326,12 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
444 return 0;
445 }
446
447+Authmethod method_gsskeyex = {
448+ "gssapi-keyex",
449+ userauth_gsskeyex,
450+ &options.gss_authentication
451+};
452+
453 Authmethod method_gssapi = {
454 "gssapi-with-mic",
455 userauth_gssapi,
456diff --git a/auth2.c b/auth2.c
457index 97dd2ef0..946e9235 100644
458--- a/auth2.c
459+++ b/auth2.c
460@@ -70,6 +70,7 @@ extern Authmethod method_passwd;
461 extern Authmethod method_kbdint;
462 extern Authmethod method_hostbased;
463 #ifdef GSSAPI
464+extern Authmethod method_gsskeyex;
465 extern Authmethod method_gssapi;
466 #endif
467
468@@ -77,6 +78,7 @@ Authmethod *authmethods[] = {
469 &method_none,
470 &method_pubkey,
471 #ifdef GSSAPI
472+ &method_gsskeyex,
473 &method_gssapi,
474 #endif
475 &method_passwd,
476diff --git a/canohost.c b/canohost.c
477index f71a0856..404731d2 100644
478--- a/canohost.c
479+++ b/canohost.c
480@@ -35,6 +35,99 @@
481 #include "canohost.h"
482 #include "misc.h"
483
484+/*
485+ * Returns the remote DNS hostname as a string. The returned string must not
486+ * be freed. NB. this will usually trigger a DNS query the first time it is
487+ * called.
488+ * This function does additional checks on the hostname to mitigate some
489+ * attacks on legacy rhosts-style authentication.
490+ * XXX is RhostsRSAAuthentication vulnerable to these?
491+ * XXX Can we remove these checks? (or if not, remove RhostsRSAAuthentication?)
492+ */
493+
494+char *
495+remote_hostname(struct ssh *ssh)
496+{
497+ struct sockaddr_storage from;
498+ socklen_t fromlen;
499+ struct addrinfo hints, *ai, *aitop;
500+ char name[NI_MAXHOST], ntop2[NI_MAXHOST];
501+ const char *ntop = ssh_remote_ipaddr(ssh);
502+
503+ /* Get IP address of client. */
504+ fromlen = sizeof(from);
505+ memset(&from, 0, sizeof(from));
506+ if (getpeername(ssh_packet_get_connection_in(ssh),
507+ (struct sockaddr *)&from, &fromlen) < 0) {
508+ debug("getpeername failed: %.100s", strerror(errno));
509+ return strdup(ntop);
510+ }
511+
512+ ipv64_normalise_mapped(&from, &fromlen);
513+ if (from.ss_family == AF_INET6)
514+ fromlen = sizeof(struct sockaddr_in6);
515+
516+ debug3("Trying to reverse map address %.100s.", ntop);
517+ /* Map the IP address to a host name. */
518+ if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name),
519+ NULL, 0, NI_NAMEREQD) != 0) {
520+ /* Host name not found. Use ip address. */
521+ return strdup(ntop);
522+ }
523+
524+ /*
525+ * if reverse lookup result looks like a numeric hostname,
526+ * someone is trying to trick us by PTR record like following:
527+ * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5
528+ */
529+ memset(&hints, 0, sizeof(hints));
530+ hints.ai_socktype = SOCK_DGRAM; /*dummy*/
531+ hints.ai_flags = AI_NUMERICHOST;
532+ if (getaddrinfo(name, NULL, &hints, &ai) == 0) {
533+ logit("Nasty PTR record \"%s\" is set up for %s, ignoring",
534+ name, ntop);
535+ freeaddrinfo(ai);
536+ return strdup(ntop);
537+ }
538+
539+ /* Names are stored in lowercase. */
540+ lowercase(name);
541+
542+ /*
543+ * Map it back to an IP address and check that the given
544+ * address actually is an address of this host. This is
545+ * necessary because anyone with access to a name server can
546+ * define arbitrary names for an IP address. Mapping from
547+ * name to IP address can be trusted better (but can still be
548+ * fooled if the intruder has access to the name server of
549+ * the domain).
550+ */
551+ memset(&hints, 0, sizeof(hints));
552+ hints.ai_family = from.ss_family;
553+ hints.ai_socktype = SOCK_STREAM;
554+ if (getaddrinfo(name, NULL, &hints, &aitop) != 0) {
555+ logit("reverse mapping checking getaddrinfo for %.700s "
556+ "[%s] failed.", name, ntop);
557+ return strdup(ntop);
558+ }
559+ /* Look for the address from the list of addresses. */
560+ for (ai = aitop; ai; ai = ai->ai_next) {
561+ if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2,
562+ sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 &&
563+ (strcmp(ntop, ntop2) == 0))
564+ break;
565+ }
566+ freeaddrinfo(aitop);
567+ /* If we reached the end of the list, the address was not there. */
568+ if (ai == NULL) {
569+ /* Address not found for the host name. */
570+ logit("Address %.100s maps to %.600s, but this does not "
571+ "map back to the address.", ntop, name);
572+ return strdup(ntop);
573+ }
574+ return strdup(name);
575+}
576+
577 void
578 ipv64_normalise_mapped(struct sockaddr_storage *addr, socklen_t *len)
579 {
580diff --git a/canohost.h b/canohost.h
581index 26d62855..0cadc9f1 100644
582--- a/canohost.h
583+++ b/canohost.h
584@@ -15,6 +15,9 @@
585 #ifndef _CANOHOST_H
586 #define _CANOHOST_H
587
588+struct ssh;
589+
590+char *remote_hostname(struct ssh *);
591 char *get_peer_ipaddr(int);
592 int get_peer_port(int);
593 char *get_local_ipaddr(int);
594diff --git a/clientloop.c b/clientloop.c
595index 06481623..38b0330e 100644
596--- a/clientloop.c
597+++ b/clientloop.c
598@@ -113,6 +113,10 @@
599 #include "ssherr.h"
600 #include "hostfile.h"
601
602+#ifdef GSSAPI
603+#include "ssh-gss.h"
604+#endif
605+
606 /* import options */
607 extern Options options;
608
609@@ -1664,9 +1668,18 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
610 break;
611
612 /* Do channel operations unless rekeying in progress. */
613- if (!ssh_packet_is_rekeying(active_state))
614+ if (!ssh_packet_is_rekeying(active_state)) {
615 channel_after_select(readset, writeset);
616
617+#ifdef GSSAPI
618+ if (options.gss_renewal_rekey &&
619+ ssh_gssapi_credentials_updated(NULL)) {
620+ debug("credentials updated - forcing rekey");
621+ need_rekeying = 1;
622+ }
623+#endif
624+ }
625+
626 /* Buffer input from the connection. */
627 client_process_net_input(readset);
628
629diff --git a/config.h.in b/config.h.in
630index b65420e4..fd8a73f1 100644
631--- a/config.h.in
632+++ b/config.h.in
633@@ -1670,6 +1670,9 @@
634 /* Use btmp to log bad logins */
635 #undef USE_BTMP
636
637+/* platform uses an in-memory credentials cache */
638+#undef USE_CCAPI
639+
640 /* Use libedit for sftp */
641 #undef USE_LIBEDIT
642
643@@ -1685,6 +1688,9 @@
644 /* Use PIPES instead of a socketpair() */
645 #undef USE_PIPES
646
647+/* platform has the Security Authorization Session API */
648+#undef USE_SECURITY_SESSION_API
649+
650 /* Define if you have Solaris privileges */
651 #undef USE_SOLARIS_PRIVS
652
653diff --git a/configure.ac b/configure.ac
654index c2878e3d..ead34acf 100644
655--- a/configure.ac
656+++ b/configure.ac
657@@ -623,6 +623,30 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
658 [Use tunnel device compatibility to OpenBSD])
659 AC_DEFINE([SSH_TUN_PREPEND_AF], [1],
660 [Prepend the address family to IP tunnel traffic])
661+ AC_MSG_CHECKING([if we have the Security Authorization Session API])
662+ AC_TRY_COMPILE([#include <Security/AuthSession.h>],
663+ [SessionCreate(0, 0);],
664+ [ac_cv_use_security_session_api="yes"
665+ AC_DEFINE([USE_SECURITY_SESSION_API], [1],
666+ [platform has the Security Authorization Session API])
667+ LIBS="$LIBS -framework Security"
668+ AC_MSG_RESULT([yes])],
669+ [ac_cv_use_security_session_api="no"
670+ AC_MSG_RESULT([no])])
671+ AC_MSG_CHECKING([if we have an in-memory credentials cache])
672+ AC_TRY_COMPILE(
673+ [#include <Kerberos/Kerberos.h>],
674+ [cc_context_t c;
675+ (void) cc_initialize (&c, 0, NULL, NULL);],
676+ [AC_DEFINE([USE_CCAPI], [1],
677+ [platform uses an in-memory credentials cache])
678+ LIBS="$LIBS -framework Security"
679+ AC_MSG_RESULT([yes])
680+ if test "x$ac_cv_use_security_session_api" = "xno"; then
681+ AC_MSG_ERROR([*** Need a security framework to use the credentials cache API ***])
682+ fi],
683+ [AC_MSG_RESULT([no])]
684+ )
685 m4_pattern_allow([AU_IPv])
686 AC_CHECK_DECL([AU_IPv4], [],
687 AC_DEFINE([AU_IPv4], [0], [System only supports IPv4 audit records])
688diff --git a/gss-genr.c b/gss-genr.c
689index 62559ed9..0b3ae073 100644
690--- a/gss-genr.c
691+++ b/gss-genr.c
692@@ -1,7 +1,7 @@
693 /* $OpenBSD: gss-genr.c,v 1.24 2016/09/12 01:22:38 deraadt Exp $ */
694
695 /*
696- * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
697+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
698 *
699 * Redistribution and use in source and binary forms, with or without
700 * modification, are permitted provided that the following conditions
701@@ -40,12 +40,167 @@
702 #include "buffer.h"
703 #include "log.h"
704 #include "ssh2.h"
705+#include "cipher.h"
706+#include "key.h"
707+#include "kex.h"
708+#include <openssl/evp.h>
709
710 #include "ssh-gss.h"
711
712 extern u_char *session_id2;
713 extern u_int session_id2_len;
714
715+typedef struct {
716+ char *encoded;
717+ gss_OID oid;
718+} ssh_gss_kex_mapping;
719+
720+/*
721+ * XXX - It would be nice to find a more elegant way of handling the
722+ * XXX passing of the key exchange context to the userauth routines
723+ */
724+
725+Gssctxt *gss_kex_context = NULL;
726+
727+static ssh_gss_kex_mapping *gss_enc2oid = NULL;
728+
729+int
730+ssh_gssapi_oid_table_ok(void) {
731+ return (gss_enc2oid != NULL);
732+}
733+
734+/*
735+ * Return a list of the gss-group1-sha1 mechanisms supported by this program
736+ *
737+ * We test mechanisms to ensure that we can use them, to avoid starting
738+ * a key exchange with a bad mechanism
739+ */
740+
741+char *
742+ssh_gssapi_client_mechanisms(const char *host, const char *client) {
743+ gss_OID_set gss_supported;
744+ OM_uint32 min_status;
745+
746+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported)))
747+ return NULL;
748+
749+ return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism,
750+ host, client));
751+}
752+
753+char *
754+ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check,
755+ const char *host, const char *client) {
756+ Buffer buf;
757+ size_t i;
758+ int oidpos, enclen;
759+ char *mechs, *encoded;
760+ u_char digest[EVP_MAX_MD_SIZE];
761+ char deroid[2];
762+ const EVP_MD *evp_md = EVP_md5();
763+ EVP_MD_CTX md;
764+
765+ if (gss_enc2oid != NULL) {
766+ for (i = 0; gss_enc2oid[i].encoded != NULL; i++)
767+ free(gss_enc2oid[i].encoded);
768+ free(gss_enc2oid);
769+ }
770+
771+ gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) *
772+ (gss_supported->count + 1));
773+
774+ buffer_init(&buf);
775+
776+ oidpos = 0;
777+ for (i = 0; i < gss_supported->count; i++) {
778+ if (gss_supported->elements[i].length < 128 &&
779+ (*check)(NULL, &(gss_supported->elements[i]), host, client)) {
780+
781+ deroid[0] = SSH_GSS_OIDTYPE;
782+ deroid[1] = gss_supported->elements[i].length;
783+
784+ EVP_DigestInit(&md, evp_md);
785+ EVP_DigestUpdate(&md, deroid, 2);
786+ EVP_DigestUpdate(&md,
787+ gss_supported->elements[i].elements,
788+ gss_supported->elements[i].length);
789+ EVP_DigestFinal(&md, digest, NULL);
790+
791+ encoded = xmalloc(EVP_MD_size(evp_md) * 2);
792+ enclen = __b64_ntop(digest, EVP_MD_size(evp_md),
793+ encoded, EVP_MD_size(evp_md) * 2);
794+
795+ if (oidpos != 0)
796+ buffer_put_char(&buf, ',');
797+
798+ buffer_append(&buf, KEX_GSS_GEX_SHA1_ID,
799+ sizeof(KEX_GSS_GEX_SHA1_ID) - 1);
800+ buffer_append(&buf, encoded, enclen);
801+ buffer_put_char(&buf, ',');
802+ buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID,
803+ sizeof(KEX_GSS_GRP1_SHA1_ID) - 1);
804+ buffer_append(&buf, encoded, enclen);
805+ buffer_put_char(&buf, ',');
806+ buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID,
807+ sizeof(KEX_GSS_GRP14_SHA1_ID) - 1);
808+ buffer_append(&buf, encoded, enclen);
809+
810+ gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]);
811+ gss_enc2oid[oidpos].encoded = encoded;
812+ oidpos++;
813+ }
814+ }
815+ gss_enc2oid[oidpos].oid = NULL;
816+ gss_enc2oid[oidpos].encoded = NULL;
817+
818+ buffer_put_char(&buf, '\0');
819+
820+ mechs = xmalloc(buffer_len(&buf));
821+ buffer_get(&buf, mechs, buffer_len(&buf));
822+ buffer_free(&buf);
823+
824+ if (strlen(mechs) == 0) {
825+ free(mechs);
826+ mechs = NULL;
827+ }
828+
829+ return (mechs);
830+}
831+
832+gss_OID
833+ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) {
834+ int i = 0;
835+
836+ switch (kex_type) {
837+ case KEX_GSS_GRP1_SHA1:
838+ if (strlen(name) < sizeof(KEX_GSS_GRP1_SHA1_ID))
839+ return GSS_C_NO_OID;
840+ name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1;
841+ break;
842+ case KEX_GSS_GRP14_SHA1:
843+ if (strlen(name) < sizeof(KEX_GSS_GRP14_SHA1_ID))
844+ return GSS_C_NO_OID;
845+ name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1;
846+ break;
847+ case KEX_GSS_GEX_SHA1:
848+ if (strlen(name) < sizeof(KEX_GSS_GEX_SHA1_ID))
849+ return GSS_C_NO_OID;
850+ name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1;
851+ break;
852+ default:
853+ return GSS_C_NO_OID;
854+ }
855+
856+ while (gss_enc2oid[i].encoded != NULL &&
857+ strcmp(name, gss_enc2oid[i].encoded) != 0)
858+ i++;
859+
860+ if (gss_enc2oid[i].oid != NULL && ctx != NULL)
861+ ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid);
862+
863+ return gss_enc2oid[i].oid;
864+}
865+
866 /* Check that the OID in a data stream matches that in the context */
867 int
868 ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
869@@ -198,7 +353,7 @@ ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
870 }
871
872 ctx->major = gss_init_sec_context(&ctx->minor,
873- GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
874+ ctx->client_creds, &ctx->context, ctx->name, ctx->oid,
875 GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
876 0, NULL, recv_tok, NULL, send_tok, flags, NULL);
877
878@@ -227,9 +382,43 @@ ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
879 return (ctx->major);
880 }
881
882+OM_uint32
883+ssh_gssapi_client_identity(Gssctxt *ctx, const char *name)
884+{
885+ gss_buffer_desc gssbuf;
886+ gss_name_t gssname;
887+ OM_uint32 status;
888+ gss_OID_set oidset;
889+
890+ gssbuf.value = (void *) name;
891+ gssbuf.length = strlen(gssbuf.value);
892+
893+ gss_create_empty_oid_set(&status, &oidset);
894+ gss_add_oid_set_member(&status, ctx->oid, &oidset);
895+
896+ ctx->major = gss_import_name(&ctx->minor, &gssbuf,
897+ GSS_C_NT_USER_NAME, &gssname);
898+
899+ if (!ctx->major)
900+ ctx->major = gss_acquire_cred(&ctx->minor,
901+ gssname, 0, oidset, GSS_C_INITIATE,
902+ &ctx->client_creds, NULL, NULL);
903+
904+ gss_release_name(&status, &gssname);
905+ gss_release_oid_set(&status, &oidset);
906+
907+ if (ctx->major)
908+ ssh_gssapi_error(ctx);
909+
910+ return(ctx->major);
911+}
912+
913 OM_uint32
914 ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
915 {
916+ if (ctx == NULL)
917+ return -1;
918+
919 if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
920 GSS_C_QOP_DEFAULT, buffer, hash)))
921 ssh_gssapi_error(ctx);
922@@ -237,6 +426,19 @@ ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
923 return (ctx->major);
924 }
925
926+/* Priviledged when used by server */
927+OM_uint32
928+ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
929+{
930+ if (ctx == NULL)
931+ return -1;
932+
933+ ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
934+ gssbuf, gssmic, NULL);
935+
936+ return (ctx->major);
937+}
938+
939 void
940 ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
941 const char *context)
942@@ -250,11 +452,16 @@ ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
943 }
944
945 int
946-ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
947+ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host,
948+ const char *client)
949 {
950 gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
951 OM_uint32 major, minor;
952 gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
953+ Gssctxt *intctx = NULL;
954+
955+ if (ctx == NULL)
956+ ctx = &intctx;
957
958 /* RFC 4462 says we MUST NOT do SPNEGO */
959 if (oid->length == spnego_oid.length &&
960@@ -264,6 +471,10 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
961 ssh_gssapi_build_ctx(ctx);
962 ssh_gssapi_set_oid(*ctx, oid);
963 major = ssh_gssapi_import_name(*ctx, host);
964+
965+ if (!GSS_ERROR(major) && client)
966+ major = ssh_gssapi_client_identity(*ctx, client);
967+
968 if (!GSS_ERROR(major)) {
969 major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token,
970 NULL);
971@@ -273,10 +484,66 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
972 GSS_C_NO_BUFFER);
973 }
974
975- if (GSS_ERROR(major))
976+ if (GSS_ERROR(major) || intctx != NULL)
977 ssh_gssapi_delete_ctx(ctx);
978
979 return (!GSS_ERROR(major));
980 }
981
982+int
983+ssh_gssapi_credentials_updated(Gssctxt *ctxt) {
984+ static gss_name_t saved_name = GSS_C_NO_NAME;
985+ static OM_uint32 saved_lifetime = 0;
986+ static gss_OID saved_mech = GSS_C_NO_OID;
987+ static gss_name_t name;
988+ static OM_uint32 last_call = 0;
989+ OM_uint32 lifetime, now, major, minor;
990+ int equal;
991+
992+ now = time(NULL);
993+
994+ if (ctxt) {
995+ debug("Rekey has happened - updating saved versions");
996+
997+ if (saved_name != GSS_C_NO_NAME)
998+ gss_release_name(&minor, &saved_name);
999+
1000+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
1001+ &saved_name, &saved_lifetime, NULL, NULL);
1002+
1003+ if (!GSS_ERROR(major)) {
1004+ saved_mech = ctxt->oid;
1005+ saved_lifetime+= now;
1006+ } else {
1007+ /* Handle the error */
1008+ }
1009+ return 0;
1010+ }
1011+
1012+ if (now - last_call < 10)
1013+ return 0;
1014+
1015+ last_call = now;
1016+
1017+ if (saved_mech == GSS_C_NO_OID)
1018+ return 0;
1019+
1020+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
1021+ &name, &lifetime, NULL, NULL);
1022+ if (major == GSS_S_CREDENTIALS_EXPIRED)
1023+ return 0;
1024+ else if (GSS_ERROR(major))
1025+ return 0;
1026+
1027+ major = gss_compare_name(&minor, saved_name, name, &equal);
1028+ gss_release_name(&minor, &name);
1029+ if (GSS_ERROR(major))
1030+ return 0;
1031+
1032+ if (equal && (saved_lifetime < lifetime + now - 10))
1033+ return 1;
1034+
1035+ return 0;
1036+}
1037+
1038 #endif /* GSSAPI */
1039diff --git a/gss-serv-krb5.c b/gss-serv-krb5.c
1040index 795992d9..fd8b3718 100644
1041--- a/gss-serv-krb5.c
1042+++ b/gss-serv-krb5.c
1043@@ -1,7 +1,7 @@
1044 /* $OpenBSD: gss-serv-krb5.c,v 1.8 2013/07/20 01:55:13 djm Exp $ */
1045
1046 /*
1047- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
1048+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
1049 *
1050 * Redistribution and use in source and binary forms, with or without
1051 * modification, are permitted provided that the following conditions
1052@@ -121,8 +121,8 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
1053 krb5_error_code problem;
1054 krb5_principal princ;
1055 OM_uint32 maj_status, min_status;
1056- int len;
1057 const char *errmsg;
1058+ const char *new_ccname;
1059
1060 if (client->creds == NULL) {
1061 debug("No credentials stored");
1062@@ -181,11 +181,16 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
1063 return;
1064 }
1065
1066- client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache));
1067+ new_ccname = krb5_cc_get_name(krb_context, ccache);
1068+
1069 client->store.envvar = "KRB5CCNAME";
1070- len = strlen(client->store.filename) + 6;
1071- client->store.envval = xmalloc(len);
1072- snprintf(client->store.envval, len, "FILE:%s", client->store.filename);
1073+#ifdef USE_CCAPI
1074+ xasprintf(&client->store.envval, "API:%s", new_ccname);
1075+ client->store.filename = NULL;
1076+#else
1077+ xasprintf(&client->store.envval, "FILE:%s", new_ccname);
1078+ client->store.filename = xstrdup(new_ccname);
1079+#endif
1080
1081 #ifdef USE_PAM
1082 if (options.use_pam)
1083@@ -197,6 +202,71 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
1084 return;
1085 }
1086
1087+int
1088+ssh_gssapi_krb5_updatecreds(ssh_gssapi_ccache *store,
1089+ ssh_gssapi_client *client)
1090+{
1091+ krb5_ccache ccache = NULL;
1092+ krb5_principal principal = NULL;
1093+ char *name = NULL;
1094+ krb5_error_code problem;
1095+ OM_uint32 maj_status, min_status;
1096+
1097+ if ((problem = krb5_cc_resolve(krb_context, store->envval, &ccache))) {
1098+ logit("krb5_cc_resolve(): %.100s",
1099+ krb5_get_err_text(krb_context, problem));
1100+ return 0;
1101+ }
1102+
1103+ /* Find out who the principal in this cache is */
1104+ if ((problem = krb5_cc_get_principal(krb_context, ccache,
1105+ &principal))) {
1106+ logit("krb5_cc_get_principal(): %.100s",
1107+ krb5_get_err_text(krb_context, problem));
1108+ krb5_cc_close(krb_context, ccache);
1109+ return 0;
1110+ }
1111+
1112+ if ((problem = krb5_unparse_name(krb_context, principal, &name))) {
1113+ logit("krb5_unparse_name(): %.100s",
1114+ krb5_get_err_text(krb_context, problem));
1115+ krb5_free_principal(krb_context, principal);
1116+ krb5_cc_close(krb_context, ccache);
1117+ return 0;
1118+ }
1119+
1120+
1121+ if (strcmp(name,client->exportedname.value)!=0) {
1122+ debug("Name in local credentials cache differs. Not storing");
1123+ krb5_free_principal(krb_context, principal);
1124+ krb5_cc_close(krb_context, ccache);
1125+ krb5_free_unparsed_name(krb_context, name);
1126+ return 0;
1127+ }
1128+ krb5_free_unparsed_name(krb_context, name);
1129+
1130+ /* Name matches, so lets get on with it! */
1131+
1132+ if ((problem = krb5_cc_initialize(krb_context, ccache, principal))) {
1133+ logit("krb5_cc_initialize(): %.100s",
1134+ krb5_get_err_text(krb_context, problem));
1135+ krb5_free_principal(krb_context, principal);
1136+ krb5_cc_close(krb_context, ccache);
1137+ return 0;
1138+ }
1139+
1140+ krb5_free_principal(krb_context, principal);
1141+
1142+ if ((maj_status = gss_krb5_copy_ccache(&min_status, client->creds,
1143+ ccache))) {
1144+ logit("gss_krb5_copy_ccache() failed. Sorry!");
1145+ krb5_cc_close(krb_context, ccache);
1146+ return 0;
1147+ }
1148+
1149+ return 1;
1150+}
1151+
1152 ssh_gssapi_mech gssapi_kerberos_mech = {
1153 "toWM5Slw5Ew8Mqkay+al2g==",
1154 "Kerberos",
1155@@ -204,7 +274,8 @@ ssh_gssapi_mech gssapi_kerberos_mech = {
1156 NULL,
1157 &ssh_gssapi_krb5_userok,
1158 NULL,
1159- &ssh_gssapi_krb5_storecreds
1160+ &ssh_gssapi_krb5_storecreds,
1161+ &ssh_gssapi_krb5_updatecreds
1162 };
1163
1164 #endif /* KRB5 */
1165diff --git a/gss-serv.c b/gss-serv.c
1166index 53993d67..2e27cbf9 100644
1167--- a/gss-serv.c
1168+++ b/gss-serv.c
1169@@ -1,7 +1,7 @@
1170 /* $OpenBSD: gss-serv.c,v 1.29 2015/05/22 03:50:02 djm Exp $ */
1171
1172 /*
1173- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
1174+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
1175 *
1176 * Redistribution and use in source and binary forms, with or without
1177 * modification, are permitted provided that the following conditions
1178@@ -45,17 +45,22 @@
1179 #include "session.h"
1180 #include "misc.h"
1181 #include "servconf.h"
1182+#include "uidswap.h"
1183
1184 #include "ssh-gss.h"
1185+#include "monitor_wrap.h"
1186+
1187+extern ServerOptions options;
1188
1189 extern ServerOptions options;
1190
1191 static ssh_gssapi_client gssapi_client =
1192 { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER,
1193- GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL, NULL}};
1194+ GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, NULL,
1195+ {NULL, NULL, NULL, NULL, NULL}, 0, 0};
1196
1197 ssh_gssapi_mech gssapi_null_mech =
1198- { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL};
1199+ { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL};
1200
1201 #ifdef KRB5
1202 extern ssh_gssapi_mech gssapi_kerberos_mech;
1203@@ -141,6 +146,28 @@ ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
1204 return (ssh_gssapi_acquire_cred(*ctx));
1205 }
1206
1207+/* Unprivileged */
1208+char *
1209+ssh_gssapi_server_mechanisms(void) {
1210+ if (supported_oids == NULL)
1211+ ssh_gssapi_prepare_supported_oids();
1212+ return (ssh_gssapi_kex_mechs(supported_oids,
1213+ &ssh_gssapi_server_check_mech, NULL, NULL));
1214+}
1215+
1216+/* Unprivileged */
1217+int
1218+ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data,
1219+ const char *dummy) {
1220+ Gssctxt *ctx = NULL;
1221+ int res;
1222+
1223+ res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid)));
1224+ ssh_gssapi_delete_ctx(&ctx);
1225+
1226+ return (res);
1227+}
1228+
1229 /* Unprivileged */
1230 void
1231 ssh_gssapi_supported_oids(gss_OID_set *oidset)
1232@@ -151,7 +178,9 @@ ssh_gssapi_supported_oids(gss_OID_set *oidset)
1233 gss_OID_set supported;
1234
1235 gss_create_empty_oid_set(&min_status, oidset);
1236- gss_indicate_mechs(&min_status, &supported);
1237+
1238+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported)))
1239+ return;
1240
1241 while (supported_mechs[i]->name != NULL) {
1242 if (GSS_ERROR(gss_test_oid_set_member(&min_status,
1243@@ -277,8 +306,48 @@ OM_uint32
1244 ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
1245 {
1246 int i = 0;
1247+ int equal = 0;
1248+ gss_name_t new_name = GSS_C_NO_NAME;
1249+ gss_buffer_desc ename = GSS_C_EMPTY_BUFFER;
1250+
1251+ if (options.gss_store_rekey && client->used && ctx->client_creds) {
1252+ if (client->mech->oid.length != ctx->oid->length ||
1253+ (memcmp(client->mech->oid.elements,
1254+ ctx->oid->elements, ctx->oid->length) !=0)) {
1255+ debug("Rekeyed credentials have different mechanism");
1256+ return GSS_S_COMPLETE;
1257+ }
1258+
1259+ if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
1260+ ctx->client_creds, ctx->oid, &new_name,
1261+ NULL, NULL, NULL))) {
1262+ ssh_gssapi_error(ctx);
1263+ return (ctx->major);
1264+ }
1265+
1266+ ctx->major = gss_compare_name(&ctx->minor, client->name,
1267+ new_name, &equal);
1268+
1269+ if (GSS_ERROR(ctx->major)) {
1270+ ssh_gssapi_error(ctx);
1271+ return (ctx->major);
1272+ }
1273+
1274+ if (!equal) {
1275+ debug("Rekeyed credentials have different name");
1276+ return GSS_S_COMPLETE;
1277+ }
1278
1279- gss_buffer_desc ename;
1280+ debug("Marking rekeyed credentials for export");
1281+
1282+ gss_release_name(&ctx->minor, &client->name);
1283+ gss_release_cred(&ctx->minor, &client->creds);
1284+ client->name = new_name;
1285+ client->creds = ctx->client_creds;
1286+ ctx->client_creds = GSS_C_NO_CREDENTIAL;
1287+ client->updated = 1;
1288+ return GSS_S_COMPLETE;
1289+ }
1290
1291 client->mech = NULL;
1292
1293@@ -293,6 +362,13 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
1294 if (client->mech == NULL)
1295 return GSS_S_FAILURE;
1296
1297+ if (ctx->client_creds &&
1298+ (ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
1299+ ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) {
1300+ ssh_gssapi_error(ctx);
1301+ return (ctx->major);
1302+ }
1303+
1304 if ((ctx->major = gss_display_name(&ctx->minor, ctx->client,
1305 &client->displayname, NULL))) {
1306 ssh_gssapi_error(ctx);
1307@@ -310,6 +386,8 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
1308 return (ctx->major);
1309 }
1310
1311+ gss_release_buffer(&ctx->minor, &ename);
1312+
1313 /* We can't copy this structure, so we just move the pointer to it */
1314 client->creds = ctx->client_creds;
1315 ctx->client_creds = GSS_C_NO_CREDENTIAL;
1316@@ -357,7 +435,7 @@ ssh_gssapi_do_child(char ***envp, u_int *envsizep)
1317
1318 /* Privileged */
1319 int
1320-ssh_gssapi_userok(char *user)
1321+ssh_gssapi_userok(char *user, struct passwd *pw)
1322 {
1323 OM_uint32 lmin;
1324
1325@@ -367,9 +445,11 @@ ssh_gssapi_userok(char *user)
1326 return 0;
1327 }
1328 if (gssapi_client.mech && gssapi_client.mech->userok)
1329- if ((*gssapi_client.mech->userok)(&gssapi_client, user))
1330+ if ((*gssapi_client.mech->userok)(&gssapi_client, user)) {
1331+ gssapi_client.used = 1;
1332+ gssapi_client.store.owner = pw;
1333 return 1;
1334- else {
1335+ } else {
1336 /* Destroy delegated credentials if userok fails */
1337 gss_release_buffer(&lmin, &gssapi_client.displayname);
1338 gss_release_buffer(&lmin, &gssapi_client.exportedname);
1339@@ -383,14 +463,90 @@ ssh_gssapi_userok(char *user)
1340 return (0);
1341 }
1342
1343-/* Privileged */
1344-OM_uint32
1345-ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
1346+/* These bits are only used for rekeying. The unpriviledged child is running
1347+ * as the user, the monitor is root.
1348+ *
1349+ * In the child, we want to :
1350+ * *) Ask the monitor to store our credentials into the store we specify
1351+ * *) If it succeeds, maybe do a PAM update
1352+ */
1353+
1354+/* Stuff for PAM */
1355+
1356+#ifdef USE_PAM
1357+static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg,
1358+ struct pam_response **resp, void *data)
1359 {
1360- ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
1361- gssbuf, gssmic, NULL);
1362+ return (PAM_CONV_ERR);
1363+}
1364+#endif
1365
1366- return (ctx->major);
1367+void
1368+ssh_gssapi_rekey_creds(void) {
1369+ int ok;
1370+ int ret;
1371+#ifdef USE_PAM
1372+ pam_handle_t *pamh = NULL;
1373+ struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL};
1374+ char *envstr;
1375+#endif
1376+
1377+ if (gssapi_client.store.filename == NULL &&
1378+ gssapi_client.store.envval == NULL &&
1379+ gssapi_client.store.envvar == NULL)
1380+ return;
1381+
1382+ ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store));
1383+
1384+ if (!ok)
1385+ return;
1386+
1387+ debug("Rekeyed credentials stored successfully");
1388+
1389+ /* Actually managing to play with the ssh pam stack from here will
1390+ * be next to impossible. In any case, we may want different options
1391+ * for rekeying. So, use our own :)
1392+ */
1393+#ifdef USE_PAM
1394+ if (!use_privsep) {
1395+ debug("Not even going to try and do PAM with privsep disabled");
1396+ return;
1397+ }
1398+
1399+ ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name,
1400+ &pamconv, &pamh);
1401+ if (ret)
1402+ return;
1403+
1404+ xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar,
1405+ gssapi_client.store.envval);
1406+
1407+ ret = pam_putenv(pamh, envstr);
1408+ if (!ret)
1409+ pam_setcred(pamh, PAM_REINITIALIZE_CRED);
1410+ pam_end(pamh, PAM_SUCCESS);
1411+#endif
1412+}
1413+
1414+int
1415+ssh_gssapi_update_creds(ssh_gssapi_ccache *store) {
1416+ int ok = 0;
1417+
1418+ /* Check we've got credentials to store */
1419+ if (!gssapi_client.updated)
1420+ return 0;
1421+
1422+ gssapi_client.updated = 0;
1423+
1424+ temporarily_use_uid(gssapi_client.store.owner);
1425+ if (gssapi_client.mech && gssapi_client.mech->updatecreds)
1426+ ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client);
1427+ else
1428+ debug("No update function for this mechanism");
1429+
1430+ restore_uid();
1431+
1432+ return ok;
1433 }
1434
1435 #endif
1436diff --git a/kex.c b/kex.c
1437index cf4ac0dc..556a32e9 100644
1438--- a/kex.c
1439+++ b/kex.c
1440@@ -54,6 +54,10 @@
1441 #include "sshbuf.h"
1442 #include "digest.h"
1443
1444+#ifdef GSSAPI
1445+#include "ssh-gss.h"
1446+#endif
1447+
1448 #if OPENSSL_VERSION_NUMBER >= 0x00907000L
1449 # if defined(HAVE_EVP_SHA256)
1450 # define evp_ssh_sha256 EVP_sha256
1451@@ -113,6 +117,14 @@ static const struct kexalg kexalgs[] = {
1452 #endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */
1453 { NULL, -1, -1, -1},
1454 };
1455+static const struct kexalg kexalg_prefixes[] = {
1456+#ifdef GSSAPI
1457+ { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
1458+ { KEX_GSS_GRP1_SHA1_ID, KEX_GSS_GRP1_SHA1, 0, SSH_DIGEST_SHA1 },
1459+ { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
1460+#endif
1461+ { NULL, -1, -1, -1 },
1462+};
1463
1464 char *
1465 kex_alg_list(char sep)
1466@@ -145,6 +157,10 @@ kex_alg_by_name(const char *name)
1467 if (strcmp(k->name, name) == 0)
1468 return k;
1469 }
1470+ for (k = kexalg_prefixes; k->name != NULL; k++) {
1471+ if (strncmp(k->name, name, strlen(k->name)) == 0)
1472+ return k;
1473+ }
1474 return NULL;
1475 }
1476
1477@@ -605,6 +621,9 @@ kex_free(struct kex *kex)
1478 sshbuf_free(kex->peer);
1479 sshbuf_free(kex->my);
1480 free(kex->session_id);
1481+#ifdef GSSAPI
1482+ free(kex->gss_host);
1483+#endif /* GSSAPI */
1484 free(kex->client_version_string);
1485 free(kex->server_version_string);
1486 free(kex->failed_choice);
1487diff --git a/kex.h b/kex.h
1488index 3794f212..fd56171d 100644
1489--- a/kex.h
1490+++ b/kex.h
1491@@ -99,6 +99,9 @@ enum kex_exchange {
1492 KEX_DH_GEX_SHA256,
1493 KEX_ECDH_SHA2,
1494 KEX_C25519_SHA256,
1495+ KEX_GSS_GRP1_SHA1,
1496+ KEX_GSS_GRP14_SHA1,
1497+ KEX_GSS_GEX_SHA1,
1498 KEX_MAX
1499 };
1500
1501@@ -147,6 +150,12 @@ struct kex {
1502 u_int flags;
1503 int hash_alg;
1504 int ec_nid;
1505+#ifdef GSSAPI
1506+ int gss_deleg_creds;
1507+ int gss_trust_dns;
1508+ char *gss_host;
1509+ char *gss_client;
1510+#endif
1511 char *client_version_string;
1512 char *server_version_string;
1513 char *failed_choice;
1514@@ -197,6 +206,11 @@ int kexecdh_server(struct ssh *);
1515 int kexc25519_client(struct ssh *);
1516 int kexc25519_server(struct ssh *);
1517
1518+#ifdef GSSAPI
1519+int kexgss_client(struct ssh *);
1520+int kexgss_server(struct ssh *);
1521+#endif
1522+
1523 int kex_dh_hash(int, const char *, const char *,
1524 const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
1525 const BIGNUM *, const BIGNUM *, const BIGNUM *, u_char *, size_t *);
1526diff --git a/kexgssc.c b/kexgssc.c
1527new file mode 100644
1528index 00000000..10447f2b
1529--- /dev/null
1530+++ b/kexgssc.c
1531@@ -0,0 +1,338 @@
1532+/*
1533+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
1534+ *
1535+ * Redistribution and use in source and binary forms, with or without
1536+ * modification, are permitted provided that the following conditions
1537+ * are met:
1538+ * 1. Redistributions of source code must retain the above copyright
1539+ * notice, this list of conditions and the following disclaimer.
1540+ * 2. Redistributions in binary form must reproduce the above copyright
1541+ * notice, this list of conditions and the following disclaimer in the
1542+ * documentation and/or other materials provided with the distribution.
1543+ *
1544+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
1545+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
1546+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
1547+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
1548+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
1549+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1550+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1551+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1552+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1553+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1554+ */
1555+
1556+#include "includes.h"
1557+
1558+#ifdef GSSAPI
1559+
1560+#include "includes.h"
1561+
1562+#include <openssl/crypto.h>
1563+#include <openssl/bn.h>
1564+
1565+#include <string.h>
1566+
1567+#include "xmalloc.h"
1568+#include "buffer.h"
1569+#include "ssh2.h"
1570+#include "key.h"
1571+#include "cipher.h"
1572+#include "kex.h"
1573+#include "log.h"
1574+#include "packet.h"
1575+#include "dh.h"
1576+#include "digest.h"
1577+
1578+#include "ssh-gss.h"
1579+
1580+int
1581+kexgss_client(struct ssh *ssh) {
1582+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1583+ gss_buffer_desc recv_tok, gssbuf, msg_tok, *token_ptr;
1584+ Gssctxt *ctxt;
1585+ OM_uint32 maj_status, min_status, ret_flags;
1586+ u_int klen, kout, slen = 0, strlen;
1587+ DH *dh;
1588+ BIGNUM *dh_server_pub = NULL;
1589+ BIGNUM *shared_secret = NULL;
1590+ BIGNUM *p = NULL;
1591+ BIGNUM *g = NULL;
1592+ u_char *kbuf;
1593+ u_char *serverhostkey = NULL;
1594+ u_char *empty = "";
1595+ char *msg;
1596+ int type = 0;
1597+ int first = 1;
1598+ int nbits = 0, min = DH_GRP_MIN, max = DH_GRP_MAX;
1599+ u_char hash[SSH_DIGEST_MAX_LENGTH];
1600+ size_t hashlen;
1601+
1602+ /* Initialise our GSSAPI world */
1603+ ssh_gssapi_build_ctx(&ctxt);
1604+ if (ssh_gssapi_id_kex(ctxt, ssh->kex->name, ssh->kex->kex_type)
1605+ == GSS_C_NO_OID)
1606+ fatal("Couldn't identify host exchange");
1607+
1608+ if (ssh_gssapi_import_name(ctxt, ssh->kex->gss_host))
1609+ fatal("Couldn't import hostname");
1610+
1611+ if (ssh->kex->gss_client &&
1612+ ssh_gssapi_client_identity(ctxt, ssh->kex->gss_client))
1613+ fatal("Couldn't acquire client credentials");
1614+
1615+ switch (ssh->kex->kex_type) {
1616+ case KEX_GSS_GRP1_SHA1:
1617+ dh = dh_new_group1();
1618+ break;
1619+ case KEX_GSS_GRP14_SHA1:
1620+ dh = dh_new_group14();
1621+ break;
1622+ case KEX_GSS_GEX_SHA1:
1623+ debug("Doing group exchange\n");
1624+ nbits = dh_estimate(ssh->kex->we_need * 8);
1625+ packet_start(SSH2_MSG_KEXGSS_GROUPREQ);
1626+ packet_put_int(min);
1627+ packet_put_int(nbits);
1628+ packet_put_int(max);
1629+
1630+ packet_send();
1631+
1632+ packet_read_expect(SSH2_MSG_KEXGSS_GROUP);
1633+
1634+ if ((p = BN_new()) == NULL)
1635+ fatal("BN_new() failed");
1636+ packet_get_bignum2(p);
1637+ if ((g = BN_new()) == NULL)
1638+ fatal("BN_new() failed");
1639+ packet_get_bignum2(g);
1640+ packet_check_eom();
1641+
1642+ if (BN_num_bits(p) < min || BN_num_bits(p) > max)
1643+ fatal("GSSGRP_GEX group out of range: %d !< %d !< %d",
1644+ min, BN_num_bits(p), max);
1645+
1646+ dh = dh_new_group(g, p);
1647+ break;
1648+ default:
1649+ fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type);
1650+ }
1651+
1652+ /* Step 1 - e is dh->pub_key */
1653+ dh_gen_key(dh, ssh->kex->we_need * 8);
1654+
1655+ /* This is f, we initialise it now to make life easier */
1656+ dh_server_pub = BN_new();
1657+ if (dh_server_pub == NULL)
1658+ fatal("dh_server_pub == NULL");
1659+
1660+ token_ptr = GSS_C_NO_BUFFER;
1661+
1662+ do {
1663+ debug("Calling gss_init_sec_context");
1664+
1665+ maj_status = ssh_gssapi_init_ctx(ctxt,
1666+ ssh->kex->gss_deleg_creds, token_ptr, &send_tok,
1667+ &ret_flags);
1668+
1669+ if (GSS_ERROR(maj_status)) {
1670+ if (send_tok.length != 0) {
1671+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
1672+ packet_put_string(send_tok.value,
1673+ send_tok.length);
1674+ }
1675+ fatal("gss_init_context failed");
1676+ }
1677+
1678+ /* If we've got an old receive buffer get rid of it */
1679+ if (token_ptr != GSS_C_NO_BUFFER)
1680+ free(recv_tok.value);
1681+
1682+ if (maj_status == GSS_S_COMPLETE) {
1683+ /* If mutual state flag is not true, kex fails */
1684+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
1685+ fatal("Mutual authentication failed");
1686+
1687+ /* If integ avail flag is not true kex fails */
1688+ if (!(ret_flags & GSS_C_INTEG_FLAG))
1689+ fatal("Integrity check failed");
1690+ }
1691+
1692+ /*
1693+ * If we have data to send, then the last message that we
1694+ * received cannot have been a 'complete'.
1695+ */
1696+ if (send_tok.length != 0) {
1697+ if (first) {
1698+ packet_start(SSH2_MSG_KEXGSS_INIT);
1699+ packet_put_string(send_tok.value,
1700+ send_tok.length);
1701+ packet_put_bignum2(dh->pub_key);
1702+ first = 0;
1703+ } else {
1704+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
1705+ packet_put_string(send_tok.value,
1706+ send_tok.length);
1707+ }
1708+ packet_send();
1709+ gss_release_buffer(&min_status, &send_tok);
1710+
1711+ /* If we've sent them data, they should reply */
1712+ do {
1713+ type = packet_read();
1714+ if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
1715+ debug("Received KEXGSS_HOSTKEY");
1716+ if (serverhostkey)
1717+ fatal("Server host key received more than once");
1718+ serverhostkey =
1719+ packet_get_string(&slen);
1720+ }
1721+ } while (type == SSH2_MSG_KEXGSS_HOSTKEY);
1722+
1723+ switch (type) {
1724+ case SSH2_MSG_KEXGSS_CONTINUE:
1725+ debug("Received GSSAPI_CONTINUE");
1726+ if (maj_status == GSS_S_COMPLETE)
1727+ fatal("GSSAPI Continue received from server when complete");
1728+ recv_tok.value = packet_get_string(&strlen);
1729+ recv_tok.length = strlen;
1730+ break;
1731+ case SSH2_MSG_KEXGSS_COMPLETE:
1732+ debug("Received GSSAPI_COMPLETE");
1733+ packet_get_bignum2(dh_server_pub);
1734+ msg_tok.value = packet_get_string(&strlen);
1735+ msg_tok.length = strlen;
1736+
1737+ /* Is there a token included? */
1738+ if (packet_get_char()) {
1739+ recv_tok.value=
1740+ packet_get_string(&strlen);
1741+ recv_tok.length = strlen;
1742+ /* If we're already complete - protocol error */
1743+ if (maj_status == GSS_S_COMPLETE)
1744+ packet_disconnect("Protocol error: received token when complete");
1745+ } else {
1746+ /* No token included */
1747+ if (maj_status != GSS_S_COMPLETE)
1748+ packet_disconnect("Protocol error: did not receive final token");
1749+ }
1750+ break;
1751+ case SSH2_MSG_KEXGSS_ERROR:
1752+ debug("Received Error");
1753+ maj_status = packet_get_int();
1754+ min_status = packet_get_int();
1755+ msg = packet_get_string(NULL);
1756+ (void) packet_get_string_ptr(NULL);
1757+ fatal("GSSAPI Error: \n%.400s",msg);
1758+ default:
1759+ packet_disconnect("Protocol error: didn't expect packet type %d",
1760+ type);
1761+ }
1762+ token_ptr = &recv_tok;
1763+ } else {
1764+ /* No data, and not complete */
1765+ if (maj_status != GSS_S_COMPLETE)
1766+ fatal("Not complete, and no token output");
1767+ }
1768+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
1769+
1770+ /*
1771+ * We _must_ have received a COMPLETE message in reply from the
1772+ * server, which will have set dh_server_pub and msg_tok
1773+ */
1774+
1775+ if (type != SSH2_MSG_KEXGSS_COMPLETE)
1776+ fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it");
1777+
1778+ /* Check f in range [1, p-1] */
1779+ if (!dh_pub_is_valid(dh, dh_server_pub))
1780+ packet_disconnect("bad server public DH value");
1781+
1782+ /* compute K=f^x mod p */
1783+ klen = DH_size(dh);
1784+ kbuf = xmalloc(klen);
1785+ kout = DH_compute_key(kbuf, dh_server_pub, dh);
1786+ if (kout < 0)
1787+ fatal("DH_compute_key: failed");
1788+
1789+ shared_secret = BN_new();
1790+ if (shared_secret == NULL)
1791+ fatal("kexgss_client: BN_new failed");
1792+
1793+ if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
1794+ fatal("kexdh_client: BN_bin2bn failed");
1795+
1796+ memset(kbuf, 0, klen);
1797+ free(kbuf);
1798+
1799+ hashlen = sizeof(hash);
1800+ switch (ssh->kex->kex_type) {
1801+ case KEX_GSS_GRP1_SHA1:
1802+ case KEX_GSS_GRP14_SHA1:
1803+ kex_dh_hash(
1804+ ssh->kex->hash_alg,
1805+ ssh->kex->client_version_string,
1806+ ssh->kex->server_version_string,
1807+ buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my),
1808+ buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer),
1809+ (serverhostkey ? serverhostkey : empty), slen,
1810+ dh->pub_key, /* e */
1811+ dh_server_pub, /* f */
1812+ shared_secret, /* K */
1813+ hash, &hashlen
1814+ );
1815+ break;
1816+ case KEX_GSS_GEX_SHA1:
1817+ kexgex_hash(
1818+ ssh->kex->hash_alg,
1819+ ssh->kex->client_version_string,
1820+ ssh->kex->server_version_string,
1821+ buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my),
1822+ buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer),
1823+ (serverhostkey ? serverhostkey : empty), slen,
1824+ min, nbits, max,
1825+ dh->p, dh->g,
1826+ dh->pub_key,
1827+ dh_server_pub,
1828+ shared_secret,
1829+ hash, &hashlen
1830+ );
1831+ break;
1832+ default:
1833+ fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type);
1834+ }
1835+
1836+ gssbuf.value = hash;
1837+ gssbuf.length = hashlen;
1838+
1839+ /* Verify that the hash matches the MIC we just got. */
1840+ if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok)))
1841+ packet_disconnect("Hash's MIC didn't verify");
1842+
1843+ free(msg_tok.value);
1844+
1845+ DH_free(dh);
1846+ free(serverhostkey);
1847+ BN_clear_free(dh_server_pub);
1848+
1849+ /* save session id */
1850+ if (ssh->kex->session_id == NULL) {
1851+ ssh->kex->session_id_len = hashlen;
1852+ ssh->kex->session_id = xmalloc(ssh->kex->session_id_len);
1853+ memcpy(ssh->kex->session_id, hash, ssh->kex->session_id_len);
1854+ }
1855+
1856+ if (ssh->kex->gss_deleg_creds)
1857+ ssh_gssapi_credentials_updated(ctxt);
1858+
1859+ if (gss_kex_context == NULL)
1860+ gss_kex_context = ctxt;
1861+ else
1862+ ssh_gssapi_delete_ctx(&ctxt);
1863+
1864+ kex_derive_keys_bn(ssh, hash, hashlen, shared_secret);
1865+ BN_clear_free(shared_secret);
1866+ return kex_send_newkeys(ssh);
1867+}
1868+
1869+#endif /* GSSAPI */
1870diff --git a/kexgsss.c b/kexgsss.c
1871new file mode 100644
1872index 00000000..38ca082b
1873--- /dev/null
1874+++ b/kexgsss.c
1875@@ -0,0 +1,295 @@
1876+/*
1877+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
1878+ *
1879+ * Redistribution and use in source and binary forms, with or without
1880+ * modification, are permitted provided that the following conditions
1881+ * are met:
1882+ * 1. Redistributions of source code must retain the above copyright
1883+ * notice, this list of conditions and the following disclaimer.
1884+ * 2. Redistributions in binary form must reproduce the above copyright
1885+ * notice, this list of conditions and the following disclaimer in the
1886+ * documentation and/or other materials provided with the distribution.
1887+ *
1888+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
1889+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
1890+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
1891+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
1892+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
1893+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1894+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1895+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1896+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1897+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1898+ */
1899+
1900+#include "includes.h"
1901+
1902+#ifdef GSSAPI
1903+
1904+#include <string.h>
1905+
1906+#include <openssl/crypto.h>
1907+#include <openssl/bn.h>
1908+
1909+#include "xmalloc.h"
1910+#include "buffer.h"
1911+#include "ssh2.h"
1912+#include "key.h"
1913+#include "cipher.h"
1914+#include "kex.h"
1915+#include "log.h"
1916+#include "packet.h"
1917+#include "dh.h"
1918+#include "ssh-gss.h"
1919+#include "monitor_wrap.h"
1920+#include "misc.h"
1921+#include "servconf.h"
1922+#include "digest.h"
1923+
1924+extern ServerOptions options;
1925+
1926+int
1927+kexgss_server(struct ssh *ssh)
1928+{
1929+ OM_uint32 maj_status, min_status;
1930+
1931+ /*
1932+ * Some GSSAPI implementations use the input value of ret_flags (an
1933+ * output variable) as a means of triggering mechanism specific
1934+ * features. Initializing it to zero avoids inadvertently
1935+ * activating this non-standard behaviour.
1936+ */
1937+
1938+ OM_uint32 ret_flags = 0;
1939+ gss_buffer_desc gssbuf, recv_tok, msg_tok;
1940+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1941+ Gssctxt *ctxt = NULL;
1942+ u_int slen, klen, kout;
1943+ u_char *kbuf;
1944+ DH *dh;
1945+ int min = -1, max = -1, nbits = -1;
1946+ BIGNUM *shared_secret = NULL;
1947+ BIGNUM *dh_client_pub = NULL;
1948+ int type = 0;
1949+ gss_OID oid;
1950+ char *mechs;
1951+ u_char hash[SSH_DIGEST_MAX_LENGTH];
1952+ size_t hashlen;
1953+
1954+ /* Initialise GSSAPI */
1955+
1956+ /* If we're rekeying, privsep means that some of the private structures
1957+ * in the GSSAPI code are no longer available. This kludges them back
1958+ * into life
1959+ */
1960+ if (!ssh_gssapi_oid_table_ok()) {
1961+ mechs = ssh_gssapi_server_mechanisms();
1962+ free(mechs);
1963+ }
1964+
1965+ debug2("%s: Identifying %s", __func__, ssh->kex->name);
1966+ oid = ssh_gssapi_id_kex(NULL, ssh->kex->name, ssh->kex->kex_type);
1967+ if (oid == GSS_C_NO_OID)
1968+ fatal("Unknown gssapi mechanism");
1969+
1970+ debug2("%s: Acquiring credentials", __func__);
1971+
1972+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid))))
1973+ fatal("Unable to acquire credentials for the server");
1974+
1975+ switch (ssh->kex->kex_type) {
1976+ case KEX_GSS_GRP1_SHA1:
1977+ dh = dh_new_group1();
1978+ break;
1979+ case KEX_GSS_GRP14_SHA1:
1980+ dh = dh_new_group14();
1981+ break;
1982+ case KEX_GSS_GEX_SHA1:
1983+ debug("Doing group exchange");
1984+ packet_read_expect(SSH2_MSG_KEXGSS_GROUPREQ);
1985+ min = packet_get_int();
1986+ nbits = packet_get_int();
1987+ max = packet_get_int();
1988+ packet_check_eom();
1989+ if (max < min || nbits < min || max < nbits)
1990+ fatal("GSS_GEX, bad parameters: %d !< %d !< %d",
1991+ min, nbits, max);
1992+ dh = PRIVSEP(choose_dh(MAX(DH_GRP_MIN, min),
1993+ nbits, MIN(DH_GRP_MAX, max)));
1994+ if (dh == NULL)
1995+ packet_disconnect("Protocol error: no matching group found");
1996+
1997+ packet_start(SSH2_MSG_KEXGSS_GROUP);
1998+ packet_put_bignum2(dh->p);
1999+ packet_put_bignum2(dh->g);
2000+ packet_send();
2001+
2002+ packet_write_wait();
2003+ break;
2004+ default:
2005+ fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type);
2006+ }
2007+
2008+ dh_gen_key(dh, ssh->kex->we_need * 8);
2009+
2010+ do {
2011+ debug("Wait SSH2_MSG_GSSAPI_INIT");
2012+ type = packet_read();
2013+ switch(type) {
2014+ case SSH2_MSG_KEXGSS_INIT:
2015+ if (dh_client_pub != NULL)
2016+ fatal("Received KEXGSS_INIT after initialising");
2017+ recv_tok.value = packet_get_string(&slen);
2018+ recv_tok.length = slen;
2019+
2020+ if ((dh_client_pub = BN_new()) == NULL)
2021+ fatal("dh_client_pub == NULL");
2022+
2023+ packet_get_bignum2(dh_client_pub);
2024+
2025+ /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */
2026+ break;
2027+ case SSH2_MSG_KEXGSS_CONTINUE:
2028+ recv_tok.value = packet_get_string(&slen);
2029+ recv_tok.length = slen;
2030+ break;
2031+ default:
2032+ packet_disconnect(
2033+ "Protocol error: didn't expect packet type %d",
2034+ type);
2035+ }
2036+
2037+ maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok,
2038+ &send_tok, &ret_flags));
2039+
2040+ free(recv_tok.value);
2041+
2042+ if (maj_status != GSS_S_COMPLETE && send_tok.length == 0)
2043+ fatal("Zero length token output when incomplete");
2044+
2045+ if (dh_client_pub == NULL)
2046+ fatal("No client public key");
2047+
2048+ if (maj_status & GSS_S_CONTINUE_NEEDED) {
2049+ debug("Sending GSSAPI_CONTINUE");
2050+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
2051+ packet_put_string(send_tok.value, send_tok.length);
2052+ packet_send();
2053+ gss_release_buffer(&min_status, &send_tok);
2054+ }
2055+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
2056+
2057+ if (GSS_ERROR(maj_status)) {
2058+ if (send_tok.length > 0) {
2059+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
2060+ packet_put_string(send_tok.value, send_tok.length);
2061+ packet_send();
2062+ }
2063+ fatal("accept_ctx died");
2064+ }
2065+
2066+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
2067+ fatal("Mutual Authentication flag wasn't set");
2068+
2069+ if (!(ret_flags & GSS_C_INTEG_FLAG))
2070+ fatal("Integrity flag wasn't set");
2071+
2072+ if (!dh_pub_is_valid(dh, dh_client_pub))
2073+ packet_disconnect("bad client public DH value");
2074+
2075+ klen = DH_size(dh);
2076+ kbuf = xmalloc(klen);
2077+ kout = DH_compute_key(kbuf, dh_client_pub, dh);
2078+ if (kout < 0)
2079+ fatal("DH_compute_key: failed");
2080+
2081+ shared_secret = BN_new();
2082+ if (shared_secret == NULL)
2083+ fatal("kexgss_server: BN_new failed");
2084+
2085+ if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
2086+ fatal("kexgss_server: BN_bin2bn failed");
2087+
2088+ memset(kbuf, 0, klen);
2089+ free(kbuf);
2090+
2091+ hashlen = sizeof(hash);
2092+ switch (ssh->kex->kex_type) {
2093+ case KEX_GSS_GRP1_SHA1:
2094+ case KEX_GSS_GRP14_SHA1:
2095+ kex_dh_hash(
2096+ ssh->kex->hash_alg,
2097+ ssh->kex->client_version_string, ssh->kex->server_version_string,
2098+ buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer),
2099+ buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my),
2100+ NULL, 0, /* Change this if we start sending host keys */
2101+ dh_client_pub, dh->pub_key, shared_secret,
2102+ hash, &hashlen
2103+ );
2104+ break;
2105+ case KEX_GSS_GEX_SHA1:
2106+ kexgex_hash(
2107+ ssh->kex->hash_alg,
2108+ ssh->kex->client_version_string, ssh->kex->server_version_string,
2109+ buffer_ptr(ssh->kex->peer), buffer_len(ssh->kex->peer),
2110+ buffer_ptr(ssh->kex->my), buffer_len(ssh->kex->my),
2111+ NULL, 0,
2112+ min, nbits, max,
2113+ dh->p, dh->g,
2114+ dh_client_pub,
2115+ dh->pub_key,
2116+ shared_secret,
2117+ hash, &hashlen
2118+ );
2119+ break;
2120+ default:
2121+ fatal("%s: Unexpected KEX type %d", __func__, ssh->kex->kex_type);
2122+ }
2123+
2124+ BN_clear_free(dh_client_pub);
2125+
2126+ if (ssh->kex->session_id == NULL) {
2127+ ssh->kex->session_id_len = hashlen;
2128+ ssh->kex->session_id = xmalloc(ssh->kex->session_id_len);
2129+ memcpy(ssh->kex->session_id, hash, ssh->kex->session_id_len);
2130+ }
2131+
2132+ gssbuf.value = hash;
2133+ gssbuf.length = hashlen;
2134+
2135+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt,&gssbuf,&msg_tok))))
2136+ fatal("Couldn't get MIC");
2137+
2138+ packet_start(SSH2_MSG_KEXGSS_COMPLETE);
2139+ packet_put_bignum2(dh->pub_key);
2140+ packet_put_string(msg_tok.value,msg_tok.length);
2141+
2142+ if (send_tok.length != 0) {
2143+ packet_put_char(1); /* true */
2144+ packet_put_string(send_tok.value, send_tok.length);
2145+ } else {
2146+ packet_put_char(0); /* false */
2147+ }
2148+ packet_send();
2149+
2150+ gss_release_buffer(&min_status, &send_tok);
2151+ gss_release_buffer(&min_status, &msg_tok);
2152+
2153+ if (gss_kex_context == NULL)
2154+ gss_kex_context = ctxt;
2155+ else
2156+ ssh_gssapi_delete_ctx(&ctxt);
2157+
2158+ DH_free(dh);
2159+
2160+ kex_derive_keys_bn(ssh, hash, hashlen, shared_secret);
2161+ BN_clear_free(shared_secret);
2162+ kex_send_newkeys(ssh);
2163+
2164+ /* If this was a rekey, then save out any delegated credentials we
2165+ * just exchanged. */
2166+ if (options.gss_store_rekey)
2167+ ssh_gssapi_rekey_creds();
2168+ return 0;
2169+}
2170+#endif /* GSSAPI */
2171diff --git a/monitor.c b/monitor.c
2172index 96d22b7e..506645c7 100644
2173--- a/monitor.c
2174+++ b/monitor.c
2175@@ -157,6 +157,8 @@ int mm_answer_gss_setup_ctx(int, Buffer *);
2176 int mm_answer_gss_accept_ctx(int, Buffer *);
2177 int mm_answer_gss_userok(int, Buffer *);
2178 int mm_answer_gss_checkmic(int, Buffer *);
2179+int mm_answer_gss_sign(int, Buffer *);
2180+int mm_answer_gss_updatecreds(int, Buffer *);
2181 #endif
2182
2183 #ifdef SSH_AUDIT_EVENTS
2184@@ -230,11 +232,18 @@ struct mon_table mon_dispatch_proto20[] = {
2185 {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
2186 {MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok},
2187 {MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic},
2188+ {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign},
2189 #endif
2190 {0, 0, NULL}
2191 };
2192
2193 struct mon_table mon_dispatch_postauth20[] = {
2194+#ifdef GSSAPI
2195+ {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx},
2196+ {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
2197+ {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign},
2198+ {MONITOR_REQ_GSSUPCREDS, 0, mm_answer_gss_updatecreds},
2199+#endif
2200 #ifdef WITH_OPENSSL
2201 {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
2202 #endif
2203@@ -302,6 +311,10 @@ monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
2204 /* Permit requests for moduli and signatures */
2205 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
2206 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
2207+#ifdef GSSAPI
2208+ /* and for the GSSAPI key exchange */
2209+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
2210+#endif
2211
2212 /* The first few requests do not require asynchronous access */
2213 while (!authenticated) {
2214@@ -402,6 +415,10 @@ monitor_child_postauth(struct monitor *pmonitor)
2215 monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
2216 monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
2217 monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
2218+#ifdef GSSAPI
2219+ /* and for the GSSAPI key exchange */
2220+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
2221+#endif
2222
2223 if (!no_pty_flag) {
2224 monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
2225@@ -1606,6 +1623,13 @@ monitor_apply_keystate(struct monitor *pmonitor)
2226 # endif
2227 #endif /* WITH_OPENSSL */
2228 kex->kex[KEX_C25519_SHA256] = kexc25519_server;
2229+#ifdef GSSAPI
2230+ if (options.gss_keyex) {
2231+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
2232+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
2233+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
2234+ }
2235+#endif
2236 kex->load_host_public_key=&get_hostkey_public_by_type;
2237 kex->load_host_private_key=&get_hostkey_private_by_type;
2238 kex->host_key_index=&get_hostkey_index;
2239@@ -1685,8 +1709,8 @@ mm_answer_gss_setup_ctx(int sock, Buffer *m)
2240 OM_uint32 major;
2241 u_int len;
2242
2243- if (!options.gss_authentication)
2244- fatal("%s: GSSAPI authentication not enabled", __func__);
2245+ if (!options.gss_authentication && !options.gss_keyex)
2246+ fatal("%s: GSSAPI not enabled", __func__);
2247
2248 goid.elements = buffer_get_string(m, &len);
2249 goid.length = len;
2250@@ -1715,8 +1739,8 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m)
2251 OM_uint32 flags = 0; /* GSI needs this */
2252 u_int len;
2253
2254- if (!options.gss_authentication)
2255- fatal("%s: GSSAPI authentication not enabled", __func__);
2256+ if (!options.gss_authentication && !options.gss_keyex)
2257+ fatal("%s: GSSAPI not enabled", __func__);
2258
2259 in.value = buffer_get_string(m, &len);
2260 in.length = len;
2261@@ -1735,6 +1759,7 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m)
2262 monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
2263 monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
2264 monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
2265+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN, 1);
2266 }
2267 return (0);
2268 }
2269@@ -1746,8 +1771,8 @@ mm_answer_gss_checkmic(int sock, Buffer *m)
2270 OM_uint32 ret;
2271 u_int len;
2272
2273- if (!options.gss_authentication)
2274- fatal("%s: GSSAPI authentication not enabled", __func__);
2275+ if (!options.gss_authentication && !options.gss_keyex)
2276+ fatal("%s: GSSAPI not enabled", __func__);
2277
2278 gssbuf.value = buffer_get_string(m, &len);
2279 gssbuf.length = len;
2280@@ -1775,10 +1800,11 @@ mm_answer_gss_userok(int sock, Buffer *m)
2281 {
2282 int authenticated;
2283
2284- if (!options.gss_authentication)
2285- fatal("%s: GSSAPI authentication not enabled", __func__);
2286+ if (!options.gss_authentication && !options.gss_keyex)
2287+ fatal("%s: GSSAPI not enabled", __func__);
2288
2289- authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
2290+ authenticated = authctxt->valid &&
2291+ ssh_gssapi_userok(authctxt->user, authctxt->pw);
2292
2293 buffer_clear(m);
2294 buffer_put_int(m, authenticated);
2295@@ -1791,5 +1817,76 @@ mm_answer_gss_userok(int sock, Buffer *m)
2296 /* Monitor loop will terminate if authenticated */
2297 return (authenticated);
2298 }
2299+
2300+int
2301+mm_answer_gss_sign(int socket, Buffer *m)
2302+{
2303+ gss_buffer_desc data;
2304+ gss_buffer_desc hash = GSS_C_EMPTY_BUFFER;
2305+ OM_uint32 major, minor;
2306+ u_int len;
2307+
2308+ if (!options.gss_authentication && !options.gss_keyex)
2309+ fatal("%s: GSSAPI not enabled", __func__);
2310+
2311+ data.value = buffer_get_string(m, &len);
2312+ data.length = len;
2313+ if (data.length != 20)
2314+ fatal("%s: data length incorrect: %d", __func__,
2315+ (int) data.length);
2316+
2317+ /* Save the session ID on the first time around */
2318+ if (session_id2_len == 0) {
2319+ session_id2_len = data.length;
2320+ session_id2 = xmalloc(session_id2_len);
2321+ memcpy(session_id2, data.value, session_id2_len);
2322+ }
2323+ major = ssh_gssapi_sign(gsscontext, &data, &hash);
2324+
2325+ free(data.value);
2326+
2327+ buffer_clear(m);
2328+ buffer_put_int(m, major);
2329+ buffer_put_string(m, hash.value, hash.length);
2330+
2331+ mm_request_send(socket, MONITOR_ANS_GSSSIGN, m);
2332+
2333+ gss_release_buffer(&minor, &hash);
2334+
2335+ /* Turn on getpwnam permissions */
2336+ monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
2337+
2338+ /* And credential updating, for when rekeying */
2339+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSUPCREDS, 1);
2340+
2341+ return (0);
2342+}
2343+
2344+int
2345+mm_answer_gss_updatecreds(int socket, Buffer *m) {
2346+ ssh_gssapi_ccache store;
2347+ int ok;
2348+
2349+ if (!options.gss_authentication && !options.gss_keyex)
2350+ fatal("%s: GSSAPI not enabled", __func__);
2351+
2352+ store.filename = buffer_get_string(m, NULL);
2353+ store.envvar = buffer_get_string(m, NULL);
2354+ store.envval = buffer_get_string(m, NULL);
2355+
2356+ ok = ssh_gssapi_update_creds(&store);
2357+
2358+ free(store.filename);
2359+ free(store.envvar);
2360+ free(store.envval);
2361+
2362+ buffer_clear(m);
2363+ buffer_put_int(m, ok);
2364+
2365+ mm_request_send(socket, MONITOR_ANS_GSSUPCREDS, m);
2366+
2367+ return(0);
2368+}
2369+
2370 #endif /* GSSAPI */
2371
2372diff --git a/monitor.h b/monitor.h
2373index d68f6745..ec41404c 100644
2374--- a/monitor.h
2375+++ b/monitor.h
2376@@ -65,6 +65,9 @@ enum monitor_reqtype {
2377 MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111,
2378 MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113,
2379
2380+ MONITOR_REQ_GSSSIGN = 150, MONITOR_ANS_GSSSIGN = 151,
2381+ MONITOR_REQ_GSSUPCREDS = 152, MONITOR_ANS_GSSUPCREDS = 153,
2382+
2383 };
2384
2385 struct monitor {
2386diff --git a/monitor_wrap.c b/monitor_wrap.c
2387index 64ff9288..d5cb640a 100644
2388--- a/monitor_wrap.c
2389+++ b/monitor_wrap.c
2390@@ -924,7 +924,7 @@ mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
2391 }
2392
2393 int
2394-mm_ssh_gssapi_userok(char *user)
2395+mm_ssh_gssapi_userok(char *user, struct passwd *pw)
2396 {
2397 Buffer m;
2398 int authenticated = 0;
2399@@ -941,5 +941,50 @@ mm_ssh_gssapi_userok(char *user)
2400 debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
2401 return (authenticated);
2402 }
2403+
2404+OM_uint32
2405+mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash)
2406+{
2407+ Buffer m;
2408+ OM_uint32 major;
2409+ u_int len;
2410+
2411+ buffer_init(&m);
2412+ buffer_put_string(&m, data->value, data->length);
2413+
2414+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, &m);
2415+ mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, &m);
2416+
2417+ major = buffer_get_int(&m);
2418+ hash->value = buffer_get_string(&m, &len);
2419+ hash->length = len;
2420+
2421+ buffer_free(&m);
2422+
2423+ return(major);
2424+}
2425+
2426+int
2427+mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store)
2428+{
2429+ Buffer m;
2430+ int ok;
2431+
2432+ buffer_init(&m);
2433+
2434+ buffer_put_cstring(&m, store->filename ? store->filename : "");
2435+ buffer_put_cstring(&m, store->envvar ? store->envvar : "");
2436+ buffer_put_cstring(&m, store->envval ? store->envval : "");
2437+
2438+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, &m);
2439+ mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, &m);
2440+
2441+ ok = buffer_get_int(&m);
2442+
2443+ buffer_free(&m);
2444+
2445+ return (ok);
2446+}
2447+
2448 #endif /* GSSAPI */
2449
2450diff --git a/monitor_wrap.h b/monitor_wrap.h
2451index db5902f5..8f9dd896 100644
2452--- a/monitor_wrap.h
2453+++ b/monitor_wrap.h
2454@@ -55,8 +55,10 @@ int mm_key_verify(Key *, u_char *, u_int, u_char *, u_int);
2455 OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
2456 OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *,
2457 gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *);
2458-int mm_ssh_gssapi_userok(char *user);
2459+int mm_ssh_gssapi_userok(char *user, struct passwd *);
2460 OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
2461+OM_uint32 mm_ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
2462+int mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *);
2463 #endif
2464
2465 #ifdef USE_PAM
2466diff --git a/readconf.c b/readconf.c
2467index 9d59493f..00d9cc30 100644
2468--- a/readconf.c
2469+++ b/readconf.c
2470@@ -160,6 +160,8 @@ typedef enum {
2471 oClearAllForwardings, oNoHostAuthenticationForLocalhost,
2472 oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
2473 oAddressFamily, oGssAuthentication, oGssDelegateCreds,
2474+ oGssTrustDns, oGssKeyEx, oGssClientIdentity, oGssRenewalRekey,
2475+ oGssServerIdentity,
2476 oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
2477 oSendEnv, oControlPath, oControlMaster, oControlPersist,
2478 oHashKnownHosts,
2479@@ -196,10 +198,20 @@ static struct {
2480 /* Sometimes-unsupported options */
2481 #if defined(GSSAPI)
2482 { "gssapiauthentication", oGssAuthentication },
2483+ { "gssapikeyexchange", oGssKeyEx },
2484 { "gssapidelegatecredentials", oGssDelegateCreds },
2485+ { "gssapitrustdns", oGssTrustDns },
2486+ { "gssapiclientidentity", oGssClientIdentity },
2487+ { "gssapiserveridentity", oGssServerIdentity },
2488+ { "gssapirenewalforcesrekey", oGssRenewalRekey },
2489 # else
2490 { "gssapiauthentication", oUnsupported },
2491+ { "gssapikeyexchange", oUnsupported },
2492 { "gssapidelegatecredentials", oUnsupported },
2493+ { "gssapitrustdns", oUnsupported },
2494+ { "gssapiclientidentity", oUnsupported },
2495+ { "gssapiserveridentity", oUnsupported },
2496+ { "gssapirenewalforcesrekey", oUnsupported },
2497 #endif
2498 #ifdef ENABLE_PKCS11
2499 { "smartcarddevice", oPKCS11Provider },
2500@@ -973,10 +985,30 @@ parse_time:
2501 intptr = &options->gss_authentication;
2502 goto parse_flag;
2503
2504+ case oGssKeyEx:
2505+ intptr = &options->gss_keyex;
2506+ goto parse_flag;
2507+
2508 case oGssDelegateCreds:
2509 intptr = &options->gss_deleg_creds;
2510 goto parse_flag;
2511
2512+ case oGssTrustDns:
2513+ intptr = &options->gss_trust_dns;
2514+ goto parse_flag;
2515+
2516+ case oGssClientIdentity:
2517+ charptr = &options->gss_client_identity;
2518+ goto parse_string;
2519+
2520+ case oGssServerIdentity:
2521+ charptr = &options->gss_server_identity;
2522+ goto parse_string;
2523+
2524+ case oGssRenewalRekey:
2525+ intptr = &options->gss_renewal_rekey;
2526+ goto parse_flag;
2527+
2528 case oBatchMode:
2529 intptr = &options->batch_mode;
2530 goto parse_flag;
2531@@ -1798,7 +1830,12 @@ initialize_options(Options * options)
2532 options->pubkey_authentication = -1;
2533 options->challenge_response_authentication = -1;
2534 options->gss_authentication = -1;
2535+ options->gss_keyex = -1;
2536 options->gss_deleg_creds = -1;
2537+ options->gss_trust_dns = -1;
2538+ options->gss_renewal_rekey = -1;
2539+ options->gss_client_identity = NULL;
2540+ options->gss_server_identity = NULL;
2541 options->password_authentication = -1;
2542 options->kbd_interactive_authentication = -1;
2543 options->kbd_interactive_devices = NULL;
2544@@ -1942,8 +1979,14 @@ fill_default_options(Options * options)
2545 options->challenge_response_authentication = 1;
2546 if (options->gss_authentication == -1)
2547 options->gss_authentication = 0;
2548+ if (options->gss_keyex == -1)
2549+ options->gss_keyex = 0;
2550 if (options->gss_deleg_creds == -1)
2551 options->gss_deleg_creds = 0;
2552+ if (options->gss_trust_dns == -1)
2553+ options->gss_trust_dns = 0;
2554+ if (options->gss_renewal_rekey == -1)
2555+ options->gss_renewal_rekey = 0;
2556 if (options->password_authentication == -1)
2557 options->password_authentication = 1;
2558 if (options->kbd_interactive_authentication == -1)
2559diff --git a/readconf.h b/readconf.h
2560index cef55f71..fd3d7c75 100644
2561--- a/readconf.h
2562+++ b/readconf.h
2563@@ -45,7 +45,12 @@ typedef struct {
2564 int challenge_response_authentication;
2565 /* Try S/Key or TIS, authentication. */
2566 int gss_authentication; /* Try GSS authentication */
2567+ int gss_keyex; /* Try GSS key exchange */
2568 int gss_deleg_creds; /* Delegate GSS credentials */
2569+ int gss_trust_dns; /* Trust DNS for GSS canonicalization */
2570+ int gss_renewal_rekey; /* Credential renewal forces rekey */
2571+ char *gss_client_identity; /* Principal to initiate GSSAPI with */
2572+ char *gss_server_identity; /* GSSAPI target principal */
2573 int password_authentication; /* Try password
2574 * authentication. */
2575 int kbd_interactive_authentication; /* Try keyboard-interactive auth. */
2576diff --git a/servconf.c b/servconf.c
2577index 56b83165..d796b7c8 100644
2578--- a/servconf.c
2579+++ b/servconf.c
2580@@ -113,8 +113,10 @@ initialize_server_options(ServerOptions *options)
2581 options->kerberos_ticket_cleanup = -1;
2582 options->kerberos_get_afs_token = -1;
2583 options->gss_authentication=-1;
2584+ options->gss_keyex = -1;
2585 options->gss_cleanup_creds = -1;
2586 options->gss_strict_acceptor = -1;
2587+ options->gss_store_rekey = -1;
2588 options->password_authentication = -1;
2589 options->kbd_interactive_authentication = -1;
2590 options->challenge_response_authentication = -1;
2591@@ -267,10 +269,14 @@ fill_default_server_options(ServerOptions *options)
2592 options->kerberos_get_afs_token = 0;
2593 if (options->gss_authentication == -1)
2594 options->gss_authentication = 0;
2595+ if (options->gss_keyex == -1)
2596+ options->gss_keyex = 0;
2597 if (options->gss_cleanup_creds == -1)
2598 options->gss_cleanup_creds = 1;
2599 if (options->gss_strict_acceptor == -1)
2600 options->gss_strict_acceptor = 1;
2601+ if (options->gss_store_rekey == -1)
2602+ options->gss_store_rekey = 0;
2603 if (options->password_authentication == -1)
2604 options->password_authentication = 1;
2605 if (options->kbd_interactive_authentication == -1)
2606@@ -407,6 +413,7 @@ typedef enum {
2607 sHostKeyAlgorithms,
2608 sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile,
2609 sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor,
2610+ sGssKeyEx, sGssStoreRekey,
2611 sAcceptEnv, sPermitTunnel,
2612 sMatch, sPermitOpen, sForceCommand, sChrootDirectory,
2613 sUsePrivilegeSeparation, sAllowAgentForwarding,
2614@@ -480,12 +487,20 @@ static struct {
2615 #ifdef GSSAPI
2616 { "gssapiauthentication", sGssAuthentication, SSHCFG_ALL },
2617 { "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL },
2618+ { "gssapicleanupcreds", sGssCleanupCreds, SSHCFG_GLOBAL },
2619 { "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL },
2620+ { "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL },
2621+ { "gssapistorecredentialsonrekey", sGssStoreRekey, SSHCFG_GLOBAL },
2622 #else
2623 { "gssapiauthentication", sUnsupported, SSHCFG_ALL },
2624 { "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL },
2625+ { "gssapicleanupcreds", sUnsupported, SSHCFG_GLOBAL },
2626 { "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL },
2627+ { "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL },
2628+ { "gssapistorecredentialsonrekey", sUnsupported, SSHCFG_GLOBAL },
2629 #endif
2630+ { "gssusesessionccache", sUnsupported, SSHCFG_GLOBAL },
2631+ { "gssapiusesessioncredcache", sUnsupported, SSHCFG_GLOBAL },
2632 { "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL },
2633 { "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL },
2634 { "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL },
2635@@ -1217,6 +1232,10 @@ process_server_config_line(ServerOptions *options, char *line,
2636 intptr = &options->gss_authentication;
2637 goto parse_flag;
2638
2639+ case sGssKeyEx:
2640+ intptr = &options->gss_keyex;
2641+ goto parse_flag;
2642+
2643 case sGssCleanupCreds:
2644 intptr = &options->gss_cleanup_creds;
2645 goto parse_flag;
2646@@ -1225,6 +1244,10 @@ process_server_config_line(ServerOptions *options, char *line,
2647 intptr = &options->gss_strict_acceptor;
2648 goto parse_flag;
2649
2650+ case sGssStoreRekey:
2651+ intptr = &options->gss_store_rekey;
2652+ goto parse_flag;
2653+
2654 case sPasswordAuthentication:
2655 intptr = &options->password_authentication;
2656 goto parse_flag;
2657@@ -2250,7 +2273,10 @@ dump_config(ServerOptions *o)
2658 #endif
2659 #ifdef GSSAPI
2660 dump_cfg_fmtint(sGssAuthentication, o->gss_authentication);
2661+ dump_cfg_fmtint(sGssKeyEx, o->gss_keyex);
2662 dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds);
2663+ dump_cfg_fmtint(sGssStrictAcceptor, o->gss_strict_acceptor);
2664+ dump_cfg_fmtint(sGssStoreRekey, o->gss_store_rekey);
2665 #endif
2666 dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication);
2667 dump_cfg_fmtint(sKbdInteractiveAuthentication,
2668diff --git a/servconf.h b/servconf.h
2669index 5853a974..90dfa4c2 100644
2670--- a/servconf.h
2671+++ b/servconf.h
2672@@ -112,8 +112,10 @@ typedef struct {
2673 int kerberos_get_afs_token; /* If true, try to get AFS token if
2674 * authenticated with Kerberos. */
2675 int gss_authentication; /* If true, permit GSSAPI authentication */
2676+ int gss_keyex; /* If true, permit GSSAPI key exchange */
2677 int gss_cleanup_creds; /* If true, destroy cred cache on logout */
2678 int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */
2679+ int gss_store_rekey;
2680 int password_authentication; /* If true, permit password
2681 * authentication. */
2682 int kbd_interactive_authentication; /* If true, permit */
2683diff --git a/ssh-gss.h b/ssh-gss.h
2684index a99d7f08..914701bc 100644
2685--- a/ssh-gss.h
2686+++ b/ssh-gss.h
2687@@ -1,6 +1,6 @@
2688 /* $OpenBSD: ssh-gss.h,v 1.11 2014/02/26 20:28:44 djm Exp $ */
2689 /*
2690- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
2691+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
2692 *
2693 * Redistribution and use in source and binary forms, with or without
2694 * modification, are permitted provided that the following conditions
2695@@ -61,10 +61,22 @@
2696
2697 #define SSH_GSS_OIDTYPE 0x06
2698
2699+#define SSH2_MSG_KEXGSS_INIT 30
2700+#define SSH2_MSG_KEXGSS_CONTINUE 31
2701+#define SSH2_MSG_KEXGSS_COMPLETE 32
2702+#define SSH2_MSG_KEXGSS_HOSTKEY 33
2703+#define SSH2_MSG_KEXGSS_ERROR 34
2704+#define SSH2_MSG_KEXGSS_GROUPREQ 40
2705+#define SSH2_MSG_KEXGSS_GROUP 41
2706+#define KEX_GSS_GRP1_SHA1_ID "gss-group1-sha1-"
2707+#define KEX_GSS_GRP14_SHA1_ID "gss-group14-sha1-"
2708+#define KEX_GSS_GEX_SHA1_ID "gss-gex-sha1-"
2709+
2710 typedef struct {
2711 char *filename;
2712 char *envvar;
2713 char *envval;
2714+ struct passwd *owner;
2715 void *data;
2716 } ssh_gssapi_ccache;
2717
2718@@ -72,8 +84,11 @@ typedef struct {
2719 gss_buffer_desc displayname;
2720 gss_buffer_desc exportedname;
2721 gss_cred_id_t creds;
2722+ gss_name_t name;
2723 struct ssh_gssapi_mech_struct *mech;
2724 ssh_gssapi_ccache store;
2725+ int used;
2726+ int updated;
2727 } ssh_gssapi_client;
2728
2729 typedef struct ssh_gssapi_mech_struct {
2730@@ -84,6 +99,7 @@ typedef struct ssh_gssapi_mech_struct {
2731 int (*userok) (ssh_gssapi_client *, char *);
2732 int (*localname) (ssh_gssapi_client *, char **);
2733 void (*storecreds) (ssh_gssapi_client *);
2734+ int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *);
2735 } ssh_gssapi_mech;
2736
2737 typedef struct {
2738@@ -94,10 +110,11 @@ typedef struct {
2739 gss_OID oid; /* client */
2740 gss_cred_id_t creds; /* server */
2741 gss_name_t client; /* server */
2742- gss_cred_id_t client_creds; /* server */
2743+ gss_cred_id_t client_creds; /* both */
2744 } Gssctxt;
2745
2746 extern ssh_gssapi_mech *supported_mechs[];
2747+extern Gssctxt *gss_kex_context;
2748
2749 int ssh_gssapi_check_oid(Gssctxt *, void *, size_t);
2750 void ssh_gssapi_set_oid_data(Gssctxt *, void *, size_t);
2751@@ -119,16 +136,32 @@ void ssh_gssapi_build_ctx(Gssctxt **);
2752 void ssh_gssapi_delete_ctx(Gssctxt **);
2753 OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
2754 void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *);
2755-int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *);
2756+int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *, const char *);
2757+OM_uint32 ssh_gssapi_client_identity(Gssctxt *, const char *);
2758+int ssh_gssapi_credentials_updated(Gssctxt *);
2759
2760 /* In the server */
2761+typedef int ssh_gssapi_check_fn(Gssctxt **, gss_OID, const char *,
2762+ const char *);
2763+char *ssh_gssapi_client_mechanisms(const char *, const char *);
2764+char *ssh_gssapi_kex_mechs(gss_OID_set, ssh_gssapi_check_fn *, const char *,
2765+ const char *);
2766+gss_OID ssh_gssapi_id_kex(Gssctxt *, char *, int);
2767+int ssh_gssapi_server_check_mech(Gssctxt **,gss_OID, const char *,
2768+ const char *);
2769 OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
2770-int ssh_gssapi_userok(char *name);
2771+int ssh_gssapi_userok(char *name, struct passwd *);
2772 OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
2773 void ssh_gssapi_do_child(char ***, u_int *);
2774 void ssh_gssapi_cleanup_creds(void);
2775 void ssh_gssapi_storecreds(void);
2776
2777+char *ssh_gssapi_server_mechanisms(void);
2778+int ssh_gssapi_oid_table_ok(void);
2779+
2780+int ssh_gssapi_update_creds(ssh_gssapi_ccache *store);
2781+void ssh_gssapi_rekey_creds(void);
2782+
2783 #endif /* GSSAPI */
2784
2785 #endif /* _SSH_GSS_H */
2786diff --git a/ssh_config b/ssh_config
2787index 90fb63f0..4e879cd2 100644
2788--- a/ssh_config
2789+++ b/ssh_config
2790@@ -26,6 +26,8 @@
2791 # HostbasedAuthentication no
2792 # GSSAPIAuthentication no
2793 # GSSAPIDelegateCredentials no
2794+# GSSAPIKeyExchange no
2795+# GSSAPITrustDNS no
2796 # BatchMode no
2797 # CheckHostIP yes
2798 # AddressFamily any
2799diff --git a/ssh_config.5 b/ssh_config.5
2800index 532745b2..ec60273e 100644
2801--- a/ssh_config.5
2802+++ b/ssh_config.5
2803@@ -752,10 +752,42 @@ The default is
2804 Specifies whether user authentication based on GSSAPI is allowed.
2805 The default is
2806 .Cm no .
2807+.It Cm GSSAPIKeyExchange
2808+Specifies whether key exchange based on GSSAPI may be used. When using
2809+GSSAPI key exchange the server need not have a host key.
2810+The default is
2811+.Cm no .
2812+.It Cm GSSAPIClientIdentity
2813+If set, specifies the GSSAPI client identity that ssh should use when
2814+connecting to the server. The default is unset, which means that the default
2815+identity will be used.
2816+.It Cm GSSAPIServerIdentity
2817+If set, specifies the GSSAPI server identity that ssh should expect when
2818+connecting to the server. The default is unset, which means that the
2819+expected GSSAPI server identity will be determined from the target
2820+hostname.
2821 .It Cm GSSAPIDelegateCredentials
2822 Forward (delegate) credentials to the server.
2823 The default is
2824 .Cm no .
2825+.It Cm GSSAPIRenewalForcesRekey
2826+If set to
2827+.Cm yes
2828+then renewal of the client's GSSAPI credentials will force the rekeying of the
2829+ssh connection. With a compatible server, this can delegate the renewed
2830+credentials to a session on the server.
2831+The default is
2832+.Cm no .
2833+.It Cm GSSAPITrustDns
2834+Set to
2835+.Cm yes
2836+to indicate that the DNS is trusted to securely canonicalize
2837+the name of the host being connected to. If
2838+.Cm no ,
2839+the hostname entered on the
2840+command line will be passed untouched to the GSSAPI library.
2841+The default is
2842+.Cm no .
2843 .It Cm HashKnownHosts
2844 Indicates that
2845 .Xr ssh 1
2846diff --git a/sshconnect2.c b/sshconnect2.c
2847index f8a54bee..5743c2c4 100644
2848--- a/sshconnect2.c
2849+++ b/sshconnect2.c
2850@@ -162,6 +162,11 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
2851 struct kex *kex;
2852 int r;
2853
2854+#ifdef GSSAPI
2855+ char *orig = NULL, *gss = NULL;
2856+ char *gss_host = NULL;
2857+#endif
2858+
2859 xxx_host = host;
2860 xxx_hostaddr = hostaddr;
2861
2862@@ -192,6 +197,35 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
2863 order_hostkeyalgs(host, hostaddr, port));
2864 }
2865
2866+#ifdef GSSAPI
2867+ if (options.gss_keyex) {
2868+ /* Add the GSSAPI mechanisms currently supported on this
2869+ * client to the key exchange algorithm proposal */
2870+ orig = myproposal[PROPOSAL_KEX_ALGS];
2871+
2872+ if (options.gss_server_identity)
2873+ gss_host = xstrdup(options.gss_server_identity);
2874+ else if (options.gss_trust_dns)
2875+ gss_host = remote_hostname(active_state);
2876+ else
2877+ gss_host = xstrdup(host);
2878+
2879+ gss = ssh_gssapi_client_mechanisms(gss_host,
2880+ options.gss_client_identity);
2881+ if (gss) {
2882+ debug("Offering GSSAPI proposal: %s", gss);
2883+ xasprintf(&myproposal[PROPOSAL_KEX_ALGS],
2884+ "%s,%s", gss, orig);
2885+
2886+ /* If we've got GSSAPI algorithms, then we also
2887+ * support the 'null' hostkey, as a last resort */
2888+ orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
2889+ xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],
2890+ "%s,null", orig);
2891+ }
2892+ }
2893+#endif
2894+
2895 if (options.rekey_limit || options.rekey_interval)
2896 packet_set_rekey_limits(options.rekey_limit,
2897 options.rekey_interval);
2898@@ -213,15 +247,41 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
2899 # endif
2900 #endif
2901 kex->kex[KEX_C25519_SHA256] = kexc25519_client;
2902+#ifdef GSSAPI
2903+ if (options.gss_keyex) {
2904+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client;
2905+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client;
2906+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client;
2907+ }
2908+#endif
2909 kex->client_version_string=client_version_string;
2910 kex->server_version_string=server_version_string;
2911 kex->verify_host_key=&verify_host_key_callback;
2912
2913+#ifdef GSSAPI
2914+ if (options.gss_keyex) {
2915+ kex->gss_deleg_creds = options.gss_deleg_creds;
2916+ kex->gss_trust_dns = options.gss_trust_dns;
2917+ kex->gss_client = options.gss_client_identity;
2918+ kex->gss_host = gss_host;
2919+ }
2920+#endif
2921+
2922 dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
2923
2924 /* remove ext-info from the KEX proposals for rekeying */
2925 myproposal[PROPOSAL_KEX_ALGS] =
2926 compat_kex_proposal(options.kex_algorithms);
2927+#ifdef GSSAPI
2928+ /* repair myproposal after it was crumpled by the */
2929+ /* ext-info removal above */
2930+ if (gss) {
2931+ orig = myproposal[PROPOSAL_KEX_ALGS];
2932+ xasprintf(&myproposal[PROPOSAL_KEX_ALGS],
2933+ "%s,%s", gss, orig);
2934+ free(gss);
2935+ }
2936+#endif
2937 if ((r = kex_prop2buf(kex->my, myproposal)) != 0)
2938 fatal("kex_prop2buf: %s", ssh_err(r));
2939
2940@@ -311,6 +371,7 @@ int input_gssapi_token(int type, u_int32_t, void *);
2941 int input_gssapi_hash(int type, u_int32_t, void *);
2942 int input_gssapi_error(int, u_int32_t, void *);
2943 int input_gssapi_errtok(int, u_int32_t, void *);
2944+int userauth_gsskeyex(Authctxt *authctxt);
2945 #endif
2946
2947 void userauth(Authctxt *, char *);
2948@@ -327,6 +388,11 @@ static char *authmethods_get(void);
2949
2950 Authmethod authmethods[] = {
2951 #ifdef GSSAPI
2952+ {"gssapi-keyex",
2953+ userauth_gsskeyex,
2954+ NULL,
2955+ &options.gss_authentication,
2956+ NULL},
2957 {"gssapi-with-mic",
2958 userauth_gssapi,
2959 NULL,
2960@@ -652,25 +718,40 @@ userauth_gssapi(Authctxt *authctxt)
2961 static u_int mech = 0;
2962 OM_uint32 min;
2963 int ok = 0;
2964+ char *gss_host;
2965+
2966+ if (options.gss_server_identity)
2967+ gss_host = xstrdup(options.gss_server_identity);
2968+ else if (options.gss_trust_dns)
2969+ gss_host = remote_hostname(active_state);
2970+ else
2971+ gss_host = xstrdup(authctxt->host);
2972
2973 /* Try one GSSAPI method at a time, rather than sending them all at
2974 * once. */
2975
2976 if (gss_supported == NULL)
2977- gss_indicate_mechs(&min, &gss_supported);
2978+ if (GSS_ERROR(gss_indicate_mechs(&min, &gss_supported))) {
2979+ gss_supported = NULL;
2980+ free(gss_host);
2981+ return 0;
2982+ }
2983
2984 /* Check to see if the mechanism is usable before we offer it */
2985 while (mech < gss_supported->count && !ok) {
2986 /* My DER encoding requires length<128 */
2987 if (gss_supported->elements[mech].length < 128 &&
2988 ssh_gssapi_check_mechanism(&gssctxt,
2989- &gss_supported->elements[mech], authctxt->host)) {
2990+ &gss_supported->elements[mech], gss_host,
2991+ options.gss_client_identity)) {
2992 ok = 1; /* Mechanism works */
2993 } else {
2994 mech++;
2995 }
2996 }
2997
2998+ free(gss_host);
2999+
3000 if (!ok)
3001 return 0;
3002
3003@@ -761,8 +842,8 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt)
3004 {
3005 Authctxt *authctxt = ctxt;
3006 Gssctxt *gssctxt;
3007- int oidlen;
3008- char *oidv;
3009+ u_int oidlen;
3010+ u_char *oidv;
3011
3012 if (authctxt == NULL)
3013 fatal("input_gssapi_response: no authentication context");
3014@@ -875,6 +956,48 @@ input_gssapi_error(int type, u_int32_t plen, void *ctxt)
3015 free(lang);
3016 return 0;
3017 }
3018+
3019+int
3020+userauth_gsskeyex(Authctxt *authctxt)
3021+{
3022+ Buffer b;
3023+ gss_buffer_desc gssbuf;
3024+ gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
3025+ OM_uint32 ms;
3026+
3027+ static int attempt = 0;
3028+ if (attempt++ >= 1)
3029+ return (0);
3030+
3031+ if (gss_kex_context == NULL) {
3032+ debug("No valid Key exchange context");
3033+ return (0);
3034+ }
3035+
3036+ ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service,
3037+ "gssapi-keyex");
3038+
3039+ gssbuf.value = buffer_ptr(&b);
3040+ gssbuf.length = buffer_len(&b);
3041+
3042+ if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) {
3043+ buffer_free(&b);
3044+ return (0);
3045+ }
3046+
3047+ packet_start(SSH2_MSG_USERAUTH_REQUEST);
3048+ packet_put_cstring(authctxt->server_user);
3049+ packet_put_cstring(authctxt->service);
3050+ packet_put_cstring(authctxt->method->name);
3051+ packet_put_string(mic.value, mic.length);
3052+ packet_send();
3053+
3054+ buffer_free(&b);
3055+ gss_release_buffer(&ms, &mic);
3056+
3057+ return (1);
3058+}
3059+
3060 #endif /* GSSAPI */
3061
3062 int
3063diff --git a/sshd.c b/sshd.c
3064index 010a2c38..20a7a5f3 100644
3065--- a/sshd.c
3066+++ b/sshd.c
3067@@ -123,6 +123,10 @@
3068 #include "version.h"
3069 #include "ssherr.h"
3070
3071+#ifdef USE_SECURITY_SESSION_API
3072+#include <Security/AuthSession.h>
3073+#endif
3074+
3075 /* Re-exec fds */
3076 #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
3077 #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
3078@@ -531,7 +535,7 @@ privsep_preauth_child(void)
3079
3080 #ifdef GSSAPI
3081 /* Cache supported mechanism OIDs for later use */
3082- if (options.gss_authentication)
3083+ if (options.gss_authentication || options.gss_keyex)
3084 ssh_gssapi_prepare_supported_oids();
3085 #endif
3086
3087@@ -1719,10 +1723,13 @@ main(int ac, char **av)
3088 key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp);
3089 free(fp);
3090 }
3091+#ifndef GSSAPI
3092+ /* The GSSAPI key exchange can run without a host key */
3093 if (!sensitive_data.have_ssh2_key) {
3094 logit("sshd: no hostkeys available -- exiting.");
3095 exit(1);
3096 }
3097+#endif
3098
3099 /*
3100 * Load certificates. They are stored in an array at identical
3101@@ -1992,6 +1999,60 @@ main(int ac, char **av)
3102 remote_ip, remote_port, laddr, ssh_local_port(ssh));
3103 free(laddr);
3104
3105+#ifdef USE_SECURITY_SESSION_API
3106+ /*
3107+ * Create a new security session for use by the new user login if
3108+ * the current session is the root session or we are not launched
3109+ * by inetd (eg: debugging mode or server mode). We do not
3110+ * necessarily need to create a session if we are launched from
3111+ * inetd because Panther xinetd will create a session for us.
3112+ *
3113+ * The only case where this logic will fail is if there is an
3114+ * inetd running in a non-root session which is not creating
3115+ * new sessions for us. Then all the users will end up in the
3116+ * same session (bad).
3117+ *
3118+ * When the client exits, the session will be destroyed for us
3119+ * automatically.
3120+ *
3121+ * We must create the session before any credentials are stored
3122+ * (including AFS pags, which happens a few lines below).
3123+ */
3124+ {
3125+ OSStatus err = 0;
3126+ SecuritySessionId sid = 0;
3127+ SessionAttributeBits sattrs = 0;
3128+
3129+ err = SessionGetInfo(callerSecuritySession, &sid, &sattrs);
3130+ if (err)
3131+ error("SessionGetInfo() failed with error %.8X",
3132+ (unsigned) err);
3133+ else
3134+ debug("Current Session ID is %.8X / Session Attributes are %.8X",
3135+ (unsigned) sid, (unsigned) sattrs);
3136+
3137+ if (inetd_flag && !(sattrs & sessionIsRoot))
3138+ debug("Running in inetd mode in a non-root session... "
3139+ "assuming inetd created the session for us.");
3140+ else {
3141+ debug("Creating new security session...");
3142+ err = SessionCreate(0, sessionHasTTY | sessionIsRemote);
3143+ if (err)
3144+ error("SessionCreate() failed with error %.8X",
3145+ (unsigned) err);
3146+
3147+ err = SessionGetInfo(callerSecuritySession, &sid,
3148+ &sattrs);
3149+ if (err)
3150+ error("SessionGetInfo() failed with error %.8X",
3151+ (unsigned) err);
3152+ else
3153+ debug("New Session ID is %.8X / Session Attributes are %.8X",
3154+ (unsigned) sid, (unsigned) sattrs);
3155+ }
3156+ }
3157+#endif
3158+
3159 /*
3160 * We don't want to listen forever unless the other side
3161 * successfully authenticates itself. So we set up an alarm which is
3162@@ -2173,6 +2234,48 @@ do_ssh2_kex(void)
3163 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
3164 list_hostkey_types());
3165
3166+#ifdef GSSAPI
3167+ {
3168+ char *orig;
3169+ char *gss = NULL;
3170+ char *newstr = NULL;
3171+ orig = myproposal[PROPOSAL_KEX_ALGS];
3172+
3173+ /*
3174+ * If we don't have a host key, then there's no point advertising
3175+ * the other key exchange algorithms
3176+ */
3177+
3178+ if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0)
3179+ orig = NULL;
3180+
3181+ if (options.gss_keyex)
3182+ gss = ssh_gssapi_server_mechanisms();
3183+ else
3184+ gss = NULL;
3185+
3186+ if (gss && orig)
3187+ xasprintf(&newstr, "%s,%s", gss, orig);
3188+ else if (gss)
3189+ newstr = gss;
3190+ else if (orig)
3191+ newstr = orig;
3192+
3193+ /*
3194+ * If we've got GSSAPI mechanisms, then we've got the 'null' host
3195+ * key alg, but we can't tell people about it unless its the only
3196+ * host key algorithm we support
3197+ */
3198+ if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0)
3199+ myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null";
3200+
3201+ if (newstr)
3202+ myproposal[PROPOSAL_KEX_ALGS] = newstr;
3203+ else
3204+ fatal("No supported key exchange algorithms");
3205+ }
3206+#endif
3207+
3208 /* start key exchange */
3209 if ((r = kex_setup(active_state, myproposal)) != 0)
3210 fatal("kex_setup: %s", ssh_err(r));
3211@@ -2190,6 +2293,13 @@ do_ssh2_kex(void)
3212 # endif
3213 #endif
3214 kex->kex[KEX_C25519_SHA256] = kexc25519_server;
3215+#ifdef GSSAPI
3216+ if (options.gss_keyex) {
3217+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
3218+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
3219+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
3220+ }
3221+#endif
3222 kex->server = 1;
3223 kex->client_version_string=client_version_string;
3224 kex->server_version_string=server_version_string;
3225diff --git a/sshd_config b/sshd_config
3226index 4eb2e02e..c01dd656 100644
3227--- a/sshd_config
3228+++ b/sshd_config
3229@@ -70,6 +70,8 @@ AuthorizedKeysFile .ssh/authorized_keys
3230 # GSSAPI options
3231 #GSSAPIAuthentication no
3232 #GSSAPICleanupCredentials yes
3233+#GSSAPIStrictAcceptorCheck yes
3234+#GSSAPIKeyExchange no
3235
3236 # Set this to 'yes' to enable PAM authentication, account processing,
3237 # and session processing. If this is enabled, PAM authentication will
3238diff --git a/sshd_config.5 b/sshd_config.5
3239index ac6ccc79..3f819c76 100644
3240--- a/sshd_config.5
3241+++ b/sshd_config.5
3242@@ -627,6 +627,11 @@ The default is
3243 Specifies whether user authentication based on GSSAPI is allowed.
3244 The default is
3245 .Cm no .
3246+.It Cm GSSAPIKeyExchange
3247+Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange
3248+doesn't rely on ssh keys to verify host identity.
3249+The default is
3250+.Cm no .
3251 .It Cm GSSAPICleanupCredentials
3252 Specifies whether to automatically destroy the user's credentials cache
3253 on logout.
3254@@ -646,6 +651,11 @@ machine's default store.
3255 This facility is provided to assist with operation on multi homed machines.
3256 The default is
3257 .Cm yes .
3258+.It Cm GSSAPIStoreCredentialsOnRekey
3259+Controls whether the user's GSSAPI credentials should be updated following a
3260+successful connection rekeying. This option can be used to accepted renewed
3261+or updated credentials from a compatible client. The default is
3262+.Cm no .
3263 .It Cm HostbasedAcceptedKeyTypes
3264 Specifies the key types that will be accepted for hostbased authentication
3265 as a comma-separated pattern list.
3266diff --git a/sshkey.c b/sshkey.c
3267index 53a7674b..54001989 100644
3268--- a/sshkey.c
3269+++ b/sshkey.c
3270@@ -116,6 +116,7 @@ static const struct keytype keytypes[] = {
3271 # endif /* OPENSSL_HAS_NISTP521 */
3272 # endif /* OPENSSL_HAS_ECC */
3273 #endif /* WITH_OPENSSL */
3274+ { "null", "null", KEY_NULL, 0, 0, 0 },
3275 { NULL, NULL, -1, -1, 0, 0 }
3276 };
3277
3278@@ -204,7 +205,7 @@ sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep)
3279 const struct keytype *kt;
3280
3281 for (kt = keytypes; kt->type != -1; kt++) {
3282- if (kt->name == NULL)
3283+ if (kt->name == NULL || kt->type == KEY_NULL)
3284 continue;
3285 if (!include_sigonly && kt->sigonly)
3286 continue;
3287diff --git a/sshkey.h b/sshkey.h
3288index 1b9e42f4..f91e4a08 100644
3289--- a/sshkey.h
3290+++ b/sshkey.h
3291@@ -62,6 +62,7 @@ enum sshkey_types {
3292 KEY_DSA_CERT,
3293 KEY_ECDSA_CERT,
3294 KEY_ED25519_CERT,
3295+ KEY_NULL,
3296 KEY_UNSPEC
3297 };
3298
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-13 16:05:09 +0000