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authorColin Watson <cjwatson@debian.org>2018-08-24 12:49:36 +0100
committerColin Watson <cjwatson@debian.org>2018-08-24 12:49:36 +0100
commite6547182a54f0f268ee36e7c99319eeddffbaff2 (patch)
tree417527229ad3f3764ba71ea383f478a168895087 /auth2-gss.c
parented6ae9c1a014a08ff5db3d768f01f2e427eeb476 (diff)
parent71508e06fab14bc415a79a08f5535ad7bffa93d9 (diff)
Import openssh_7.8p1.orig.tar.gz
Diffstat (limited to 'auth2-gss.c')
-rw-r--r--auth2-gss.c107
1 files changed, 66 insertions, 41 deletions
diff --git a/auth2-gss.c b/auth2-gss.c
index 589283b72..9351e0428 100644
--- a/auth2-gss.c
+++ b/auth2-gss.c
@@ -1,4 +1,4 @@
1/* $OpenBSD: auth2-gss.c,v 1.26 2017/06/24 06:34:38 djm Exp $ */ 1/* $OpenBSD: auth2-gss.c,v 1.29 2018/07/31 03:10:27 djm Exp $ */
2 2
3/* 3/*
4 * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. 4 * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
@@ -33,13 +33,14 @@
33#include <stdarg.h> 33#include <stdarg.h>
34 34
35#include "xmalloc.h" 35#include "xmalloc.h"
36#include "key.h" 36#include "sshkey.h"
37#include "hostfile.h" 37#include "hostfile.h"
38#include "auth.h" 38#include "auth.h"
39#include "ssh2.h" 39#include "ssh2.h"
40#include "log.h" 40#include "log.h"
41#include "dispatch.h" 41#include "dispatch.h"
42#include "buffer.h" 42#include "sshbuf.h"
43#include "ssherr.h"
43#include "misc.h" 44#include "misc.h"
44#include "servconf.h" 45#include "servconf.h"
45#include "packet.h" 46#include "packet.h"
@@ -63,16 +64,15 @@ userauth_gssapi(struct ssh *ssh)
63 Authctxt *authctxt = ssh->authctxt; 64 Authctxt *authctxt = ssh->authctxt;
64 gss_OID_desc goid = {0, NULL}; 65 gss_OID_desc goid = {0, NULL};
65 Gssctxt *ctxt = NULL; 66 Gssctxt *ctxt = NULL;
66 int mechs; 67 int r, present;
67 int present; 68 u_int mechs;
68 OM_uint32 ms; 69 OM_uint32 ms;
69 u_int len; 70 size_t len;
70 u_char *doid = NULL; 71 u_char *doid = NULL;
71 72
72 if (!authctxt->valid || authctxt->user == NULL) 73 if ((r = sshpkt_get_u32(ssh, &mechs)) != 0)
73 return (0); 74 fatal("%s: %s", __func__, ssh_err(r));
74 75
75 mechs = packet_get_int();
76 if (mechs == 0) { 76 if (mechs == 0) {
77 debug("Mechanism negotiation is not supported"); 77 debug("Mechanism negotiation is not supported");
78 return (0); 78 return (0);
@@ -84,7 +84,8 @@ userauth_gssapi(struct ssh *ssh)
84 free(doid); 84 free(doid);
85 85
86 present = 0; 86 present = 0;
87 doid = packet_get_string(&len); 87 if ((r = sshpkt_get_string(ssh, &doid, &len)) != 0)
88 fatal("%s: %s", __func__, ssh_err(r));
88 89
89 if (len > 2 && doid[0] == SSH_GSS_OIDTYPE && 90 if (len > 2 && doid[0] == SSH_GSS_OIDTYPE &&
90 doid[1] == len - 2) { 91 doid[1] == len - 2) {
@@ -102,6 +103,12 @@ userauth_gssapi(struct ssh *ssh)
102 return (0); 103 return (0);
103 } 104 }
104 105
106 if (!authctxt->valid || authctxt->user == NULL) {
107 debug2("%s: disabled because of invalid user", __func__);
108 free(doid);
109 return (0);
110 }
111
105 if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) { 112 if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) {
106 if (ctxt != NULL) 113 if (ctxt != NULL)
107 ssh_gssapi_delete_ctx(&ctxt); 114 ssh_gssapi_delete_ctx(&ctxt);
@@ -112,12 +119,12 @@ userauth_gssapi(struct ssh *ssh)
112 119
113 authctxt->methoddata = (void *)ctxt; 120 authctxt->methoddata = (void *)ctxt;
114 121
115 packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
116
117 /* Return the OID that we received */ 122 /* Return the OID that we received */
118 packet_put_string(doid, len); 123 if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE)) != 0 ||
124 (r = sshpkt_put_string(ssh, doid, len)) != 0 ||
125 (r = sshpkt_send(ssh)) != 0)
126 fatal("%s: %s", __func__, ssh_err(r));
119 127
120 packet_send();
121 free(doid); 128 free(doid);
122 129
123 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); 130 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
@@ -135,36 +142,45 @@ input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
135 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; 142 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
136 gss_buffer_desc recv_tok; 143 gss_buffer_desc recv_tok;
137 OM_uint32 maj_status, min_status, flags; 144 OM_uint32 maj_status, min_status, flags;
138 u_int len; 145 u_char *p;
146 size_t len;
147 int r;
139 148
140 if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) 149 if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
141 fatal("No authentication or GSSAPI context"); 150 fatal("No authentication or GSSAPI context");
142 151
143 gssctxt = authctxt->methoddata; 152 gssctxt = authctxt->methoddata;
144 recv_tok.value = packet_get_string(&len); 153 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
145 recv_tok.length = len; /* u_int vs. size_t */ 154 (r = sshpkt_get_end(ssh)) != 0)
146 155 fatal("%s: %s", __func__, ssh_err(r));
147 packet_check_eom();
148 156
157 recv_tok.value = p;
158 recv_tok.length = len;
149 maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok, 159 maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
150 &send_tok, &flags)); 160 &send_tok, &flags));
151 161
152 free(recv_tok.value); 162 free(p);
153 163
154 if (GSS_ERROR(maj_status)) { 164 if (GSS_ERROR(maj_status)) {
155 if (send_tok.length != 0) { 165 if (send_tok.length != 0) {
156 packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); 166 if ((r = sshpkt_start(ssh,
157 packet_put_string(send_tok.value, send_tok.length); 167 SSH2_MSG_USERAUTH_GSSAPI_ERRTOK)) != 0 ||
158 packet_send(); 168 (r = sshpkt_put_string(ssh, send_tok.value,
169 send_tok.length)) != 0 ||
170 (r = sshpkt_send(ssh)) != 0)
171 fatal("%s: %s", __func__, ssh_err(r));
159 } 172 }
160 authctxt->postponed = 0; 173 authctxt->postponed = 0;
161 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); 174 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
162 userauth_finish(ssh, 0, "gssapi-with-mic", NULL); 175 userauth_finish(ssh, 0, "gssapi-with-mic", NULL);
163 } else { 176 } else {
164 if (send_tok.length != 0) { 177 if (send_tok.length != 0) {
165 packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); 178 if ((r = sshpkt_start(ssh,
166 packet_put_string(send_tok.value, send_tok.length); 179 SSH2_MSG_USERAUTH_GSSAPI_TOKEN)) != 0 ||
167 packet_send(); 180 (r = sshpkt_put_string(ssh, send_tok.value,
181 send_tok.length)) != 0 ||
182 (r = sshpkt_send(ssh)) != 0)
183 fatal("%s: %s", __func__, ssh_err(r));
168 } 184 }
169 if (maj_status == GSS_S_COMPLETE) { 185 if (maj_status == GSS_S_COMPLETE) {
170 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); 186 ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
@@ -190,17 +206,20 @@ input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
190 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; 206 gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
191 gss_buffer_desc recv_tok; 207 gss_buffer_desc recv_tok;
192 OM_uint32 maj_status; 208 OM_uint32 maj_status;
193 u_int len; 209 int r;
210 u_char *p;
211 size_t len;
194 212
195 if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) 213 if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
196 fatal("No authentication or GSSAPI context"); 214 fatal("No authentication or GSSAPI context");
197 215
198 gssctxt = authctxt->methoddata; 216 gssctxt = authctxt->methoddata;
199 recv_tok.value = packet_get_string(&len); 217 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
218 (r = sshpkt_get_end(ssh)) != 0)
219 fatal("%s: %s", __func__, ssh_err(r));
220 recv_tok.value = p;
200 recv_tok.length = len; 221 recv_tok.length = len;
201 222
202 packet_check_eom();
203
204 /* Push the error token into GSSAPI to see what it says */ 223 /* Push the error token into GSSAPI to see what it says */
205 maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok, 224 maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
206 &send_tok, NULL)); 225 &send_tok, NULL));
@@ -227,7 +246,7 @@ static int
227input_gssapi_exchange_complete(int type, u_int32_t plen, struct ssh *ssh) 246input_gssapi_exchange_complete(int type, u_int32_t plen, struct ssh *ssh)
228{ 247{
229 Authctxt *authctxt = ssh->authctxt; 248 Authctxt *authctxt = ssh->authctxt;
230 int authenticated; 249 int r, authenticated;
231 const char *displayname; 250 const char *displayname;
232 251
233 if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) 252 if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
@@ -238,7 +257,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, struct ssh *ssh)
238 * the dispatcher once the exchange is complete 257 * the dispatcher once the exchange is complete
239 */ 258 */
240 259
241 packet_check_eom(); 260 if ((r = sshpkt_get_end(ssh)) != 0)
261 fatal("%s: %s", __func__, ssh_err(r));
242 262
243 authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); 263 authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
244 264
@@ -260,32 +280,37 @@ input_gssapi_mic(int type, u_int32_t plen, struct ssh *ssh)
260{ 280{
261 Authctxt *authctxt = ssh->authctxt; 281 Authctxt *authctxt = ssh->authctxt;
262 Gssctxt *gssctxt; 282 Gssctxt *gssctxt;
263 int authenticated = 0; 283 int r, authenticated = 0;
264 Buffer b; 284 struct sshbuf *b;
265 gss_buffer_desc mic, gssbuf; 285 gss_buffer_desc mic, gssbuf;
266 u_int len;
267 const char *displayname; 286 const char *displayname;
287 u_char *p;
288 size_t len;
268 289
269 if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) 290 if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
270 fatal("No authentication or GSSAPI context"); 291 fatal("No authentication or GSSAPI context");
271 292
272 gssctxt = authctxt->methoddata; 293 gssctxt = authctxt->methoddata;
273 294
274 mic.value = packet_get_string(&len); 295 if ((r = sshpkt_get_string(ssh, &p, &len)) != 0)
296 fatal("%s: %s", __func__, ssh_err(r));
297 if ((b = sshbuf_new()) == NULL)
298 fatal("%s: sshbuf_new failed", __func__);
299 mic.value = p;
275 mic.length = len; 300 mic.length = len;
276 301 ssh_gssapi_buildmic(b, authctxt->user, authctxt->service,
277 ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
278 "gssapi-with-mic"); 302 "gssapi-with-mic");
279 303
280 gssbuf.value = buffer_ptr(&b); 304 if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
281 gssbuf.length = buffer_len(&b); 305 fatal("%s: sshbuf_mutable_ptr failed", __func__);
306 gssbuf.length = sshbuf_len(b);
282 307
283 if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic)))) 308 if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
284 authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); 309 authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
285 else 310 else
286 logit("GSSAPI MIC check failed"); 311 logit("GSSAPI MIC check failed");
287 312
288 buffer_free(&b); 313 sshbuf_free(b);
289 free(mic.value); 314 free(mic.value);
290 315
291 if ((!use_privsep || mm_is_monitor()) && 316 if ((!use_privsep || mm_is_monitor()) &&