Annotation of src/usr.bin/ssh/gss-genr.c, Revision 1.5
1.5 ! stevesk 1: /* $OpenBSD: gss-genr.c,v 1.4 2005/07/17 07:17:55 djm Exp $ */
1.1 markus 2:
3: /*
4: * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27: #include "includes.h"
28:
29: #ifdef GSSAPI
30:
31: #include "xmalloc.h"
32: #include "bufaux.h"
33: #include "log.h"
1.2 markus 34: #include "ssh2.h"
1.1 markus 35:
36: #include "ssh-gss.h"
37:
1.2 markus 38: extern u_char *session_id2;
39: extern u_int session_id2_len;
1.1 markus 40:
41: /* Check that the OID in a data stream matches that in the context */
42: int
43: ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
44: {
45: return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
46: ctx->oid->length == len &&
47: memcmp(ctx->oid->elements, data, len) == 0);
48: }
49:
50: /* Set the contexts OID from a data stream */
51: void
52: ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len)
53: {
54: if (ctx->oid != GSS_C_NO_OID) {
55: xfree(ctx->oid->elements);
56: xfree(ctx->oid);
57: }
58: ctx->oid = xmalloc(sizeof(gss_OID_desc));
59: ctx->oid->length = len;
60: ctx->oid->elements = xmalloc(len);
61: memcpy(ctx->oid->elements, data, len);
62: }
63:
64: /* Set the contexts OID */
65: void
66: ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
67: {
68: ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
69: }
70:
71: /* All this effort to report an error ... */
72: void
73: ssh_gssapi_error(Gssctxt *ctxt)
74: {
75: debug("%s", ssh_gssapi_last_error(ctxt, NULL, NULL));
76: }
77:
78: char *
1.4 djm 79: ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
80: OM_uint32 *minor_status)
1.1 markus 81: {
82: OM_uint32 lmin;
83: gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
84: OM_uint32 ctx;
85: Buffer b;
86: char *ret;
87:
88: buffer_init(&b);
89:
90: if (major_status != NULL)
91: *major_status = ctxt->major;
92: if (minor_status != NULL)
93: *minor_status = ctxt->minor;
94:
95: ctx = 0;
96: /* The GSSAPI error */
97: do {
98: gss_display_status(&lmin, ctxt->major,
99: GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);
100:
101: buffer_append(&b, msg.value, msg.length);
102: buffer_put_char(&b, '\n');
103:
104: gss_release_buffer(&lmin, &msg);
105: } while (ctx != 0);
106:
107: /* The mechanism specific error */
108: do {
109: gss_display_status(&lmin, ctxt->minor,
110: GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);
111:
112: buffer_append(&b, msg.value, msg.length);
113: buffer_put_char(&b, '\n');
114:
115: gss_release_buffer(&lmin, &msg);
116: } while (ctx != 0);
117:
118: buffer_put_char(&b, '\0');
119: ret = xmalloc(buffer_len(&b));
120: buffer_get(&b, ret, buffer_len(&b));
121: buffer_free(&b);
122: return (ret);
123: }
124:
125: /*
126: * Initialise our GSSAPI context. We use this opaque structure to contain all
127: * of the data which both the client and server need to persist across
128: * {accept,init}_sec_context calls, so that when we do it from the userauth
129: * stuff life is a little easier
130: */
131: void
132: ssh_gssapi_build_ctx(Gssctxt **ctx)
133: {
134: *ctx = xmalloc(sizeof (Gssctxt));
135: (*ctx)->major = 0;
136: (*ctx)->minor = 0;
137: (*ctx)->context = GSS_C_NO_CONTEXT;
138: (*ctx)->name = GSS_C_NO_NAME;
139: (*ctx)->oid = GSS_C_NO_OID;
140: (*ctx)->creds = GSS_C_NO_CREDENTIAL;
141: (*ctx)->client = GSS_C_NO_NAME;
142: (*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
143: }
144:
145: /* Delete our context, providing it has been built correctly */
146: void
147: ssh_gssapi_delete_ctx(Gssctxt **ctx)
148: {
149: OM_uint32 ms;
150:
151: if ((*ctx) == NULL)
152: return;
153: if ((*ctx)->context != GSS_C_NO_CONTEXT)
154: gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
155: if ((*ctx)->name != GSS_C_NO_NAME)
156: gss_release_name(&ms, &(*ctx)->name);
157: if ((*ctx)->oid != GSS_C_NO_OID) {
158: xfree((*ctx)->oid->elements);
159: xfree((*ctx)->oid);
160: (*ctx)->oid = GSS_C_NO_OID;
161: }
162: if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
163: gss_release_cred(&ms, &(*ctx)->creds);
164: if ((*ctx)->client != GSS_C_NO_NAME)
165: gss_release_name(&ms, &(*ctx)->client);
166: if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
167: gss_release_cred(&ms, &(*ctx)->client_creds);
168:
169: xfree(*ctx);
170: *ctx = NULL;
171: }
172:
173: /*
174: * Wrapper to init_sec_context
175: * Requires that the context contains:
176: * oid
177: * server name (from ssh_gssapi_import_name)
178: */
179: OM_uint32
180: ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
181: gss_buffer_desc* send_tok, OM_uint32 *flags)
182: {
183: int deleg_flag = 0;
184:
185: if (deleg_creds) {
186: deleg_flag = GSS_C_DELEG_FLAG;
187: debug("Delegating credentials");
188: }
189:
190: ctx->major = gss_init_sec_context(&ctx->minor,
191: GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
192: GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
193: 0, NULL, recv_tok, NULL, send_tok, flags, NULL);
194:
195: if (GSS_ERROR(ctx->major))
196: ssh_gssapi_error(ctx);
197:
198: return (ctx->major);
199: }
200:
201: /* Create a service name for the given host */
202: OM_uint32
203: ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
204: {
205: gss_buffer_desc gssbuf;
206:
207: gssbuf.length = sizeof("host@") + strlen(host);
208: gssbuf.value = xmalloc(gssbuf.length);
209: snprintf(gssbuf.value, gssbuf.length, "host@%s", host);
210:
211: if ((ctx->major = gss_import_name(&ctx->minor,
212: &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
213: ssh_gssapi_error(ctx);
214:
215: xfree(gssbuf.value);
216: return (ctx->major);
217: }
218:
219: /* Acquire credentials for a server running on the current host.
220: * Requires that the context structure contains a valid OID
221: */
222:
223: /* Returns a GSSAPI error code */
224: OM_uint32
225: ssh_gssapi_acquire_cred(Gssctxt *ctx)
226: {
227: OM_uint32 status;
228: char lname[MAXHOSTNAMELEN];
229: gss_OID_set oidset;
230:
231: gss_create_empty_oid_set(&status, &oidset);
232: gss_add_oid_set_member(&status, ctx->oid, &oidset);
233:
234: if (gethostname(lname, MAXHOSTNAMELEN))
235: return (-1);
236:
237: if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname)))
238: return (ctx->major);
239:
240: if ((ctx->major = gss_acquire_cred(&ctx->minor,
241: ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
242: ssh_gssapi_error(ctx);
243:
244: gss_release_oid_set(&status, &oidset);
245: return (ctx->major);
1.2 markus 246: }
247:
248: OM_uint32
249: ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
250: {
251: if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
252: GSS_C_QOP_DEFAULT, buffer, hash)))
253: ssh_gssapi_error(ctx);
1.3 djm 254:
1.2 markus 255: return (ctx->major);
256: }
257:
258: void
1.3 djm 259: ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
260: const char *context)
261: {
1.2 markus 262: buffer_init(b);
263: buffer_put_string(b, session_id2, session_id2_len);
264: buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
265: buffer_put_cstring(b, user);
266: buffer_put_cstring(b, service);
267: buffer_put_cstring(b, context);
1.1 markus 268: }
269:
270: OM_uint32
271: ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid) {
272: if (*ctx)
273: ssh_gssapi_delete_ctx(ctx);
274: ssh_gssapi_build_ctx(ctx);
275: ssh_gssapi_set_oid(*ctx, oid);
276: return (ssh_gssapi_acquire_cred(*ctx));
277: }
278:
279: #endif /* GSSAPI */