Line data Source code
1 : /*-
2 : * Copyright (c) 2005 Doug Rabson
3 : * All rights reserved.
4 : *
5 : * Redistribution and use in source and binary forms, with or without
6 : * modification, are permitted provided that the following conditions
7 : * are met:
8 : * 1. Redistributions of source code must retain the above copyright
9 : * notice, this list of conditions and the following disclaimer.
10 : * 2. Redistributions in binary form must reproduce the above copyright
11 : * notice, this list of conditions and the following disclaimer in the
12 : * documentation and/or other materials provided with the distribution.
13 : *
14 : * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 : * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 : * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 : * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 : * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 : * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 : * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 : * SUCH DAMAGE.
25 : *
26 : * $FreeBSD: src/lib/libgssapi/gss_accept_sec_context.c,v 1.1 2005/12/29 14:40:20 dfr Exp $
27 : */
28 :
29 : #include "mech_locl.h"
30 :
31 : static OM_uint32
32 44781 : parse_header(const gss_buffer_t input_token, gss_OID mech_oid)
33 : {
34 44781 : unsigned char *p = input_token->value;
35 44781 : size_t len = input_token->length;
36 : size_t a, b;
37 :
38 : /*
39 : * Token must start with [APPLICATION 0] SEQUENCE.
40 : * But if it doesn't assume it is DCE-STYLE Kerberos!
41 : */
42 44781 : if (len == 0)
43 0 : return (GSS_S_DEFECTIVE_TOKEN);
44 :
45 44781 : p++;
46 44781 : len--;
47 :
48 : /*
49 : * Decode the length and make sure it agrees with the
50 : * token length.
51 : */
52 44781 : if (len == 0)
53 0 : return (GSS_S_DEFECTIVE_TOKEN);
54 44781 : if ((*p & 0x80) == 0) {
55 2 : a = *p;
56 2 : p++;
57 2 : len--;
58 : } else {
59 44779 : b = *p & 0x7f;
60 44779 : p++;
61 44779 : len--;
62 44779 : if (len < b)
63 0 : return (GSS_S_DEFECTIVE_TOKEN);
64 44041 : a = 0;
65 178378 : while (b) {
66 89558 : a = (a << 8) | *p;
67 89558 : p++;
68 89558 : len--;
69 89558 : b--;
70 : }
71 : }
72 44781 : if (a != len)
73 0 : return (GSS_S_DEFECTIVE_TOKEN);
74 :
75 : /*
76 : * Decode the OID for the mechanism. Simplify life by
77 : * assuming that the OID length is less than 128 bytes.
78 : */
79 44781 : if (len < 2 || *p != 0x06)
80 28027 : return (GSS_S_DEFECTIVE_TOKEN);
81 16658 : if ((p[1] & 0x80) || p[1] > (len - 2))
82 0 : return (GSS_S_DEFECTIVE_TOKEN);
83 16658 : mech_oid->length = p[1];
84 16658 : p += 2;
85 16658 : len -= 2;
86 16658 : mech_oid->elements = p;
87 :
88 16658 : return GSS_S_COMPLETE;
89 : }
90 :
91 : static gss_OID_desc krb5_mechanism =
92 : {9, rk_UNCONST("\x2a\x86\x48\x86\xf7\x12\x01\x02\x02")};
93 : static gss_OID_desc ntlm_mechanism =
94 : {10, rk_UNCONST("\x2b\x06\x01\x04\x01\x82\x37\x02\x02\x0a")};
95 : static gss_OID_desc spnego_mechanism =
96 : {6, rk_UNCONST("\x2b\x06\x01\x05\x05\x02")};
97 :
98 : static OM_uint32
99 44781 : choose_mech(const gss_buffer_t input, gss_OID mech_oid)
100 : {
101 : OM_uint32 status;
102 :
103 : /*
104 : * First try to parse the gssapi token header and see if it's a
105 : * correct header, use that in the first hand.
106 : */
107 :
108 44781 : status = parse_header(input, mech_oid);
109 44781 : if (status == GSS_S_COMPLETE)
110 16016 : return GSS_S_COMPLETE;
111 :
112 : /*
113 : * Lets guess what mech is really is, callback function to mech ??
114 : */
115 :
116 56246 : if (input->length > 8 &&
117 28123 : memcmp((const char *)input->value, "NTLMSSP\x00", 8) == 0)
118 : {
119 0 : *mech_oid = ntlm_mechanism;
120 0 : return GSS_S_COMPLETE;
121 56246 : } else if (input->length != 0 &&
122 28123 : ((const char *)input->value)[0] == 0x6E)
123 : {
124 : /* Could be a raw AP-REQ (check for APPLICATION tag) */
125 28121 : *mech_oid = krb5_mechanism;
126 28121 : return GSS_S_COMPLETE;
127 2 : } else if (input->length == 0) {
128 : /*
129 : * There is the a wierd mode of SPNEGO (in CIFS and
130 : * SASL GSS-SPENGO where the first token is zero
131 : * length and the acceptor returns a mech_list, lets
132 : * hope that is what is happening now.
133 : *
134 : * http://msdn.microsoft.com/en-us/library/cc213114.aspx
135 : * "NegTokenInit2 Variation for Server-Initiation"
136 : */
137 0 : *mech_oid = spnego_mechanism;
138 0 : return GSS_S_COMPLETE;
139 : }
140 2 : return status;
141 : }
142 :
143 :
144 : GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
145 72865 : gss_accept_sec_context(OM_uint32 *minor_status,
146 : gss_ctx_id_t *context_handle,
147 : const gss_cred_id_t acceptor_cred_handle,
148 : const gss_buffer_t input_token,
149 : const gss_channel_bindings_t input_chan_bindings,
150 : gss_name_t *src_name,
151 : gss_OID *mech_type,
152 : gss_buffer_t output_token,
153 : OM_uint32 *ret_flags,
154 : OM_uint32 *time_rec,
155 : gss_cred_id_t *delegated_cred_handle)
156 : {
157 : OM_uint32 major_status, mech_ret_flags, junk;
158 : gssapi_mech_interface m;
159 72865 : struct _gss_context *ctx = (struct _gss_context *) *context_handle;
160 72865 : struct _gss_cred *cred = (struct _gss_cred *) acceptor_cred_handle;
161 : struct _gss_mechanism_cred *mc;
162 : gss_cred_id_t acceptor_mc, delegated_mc;
163 : gss_name_t src_mn;
164 72865 : gss_OID mech_ret_type = NULL;
165 :
166 72865 : *minor_status = 0;
167 72865 : if (src_name)
168 72865 : *src_name = GSS_C_NO_NAME;
169 72865 : if (mech_type)
170 72865 : *mech_type = GSS_C_NO_OID;
171 72865 : if (ret_flags)
172 72865 : *ret_flags = 0;
173 72865 : if (time_rec)
174 72865 : *time_rec = 0;
175 72865 : if (delegated_cred_handle)
176 72865 : *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
177 72865 : _mg_buffer_zero(output_token);
178 :
179 :
180 : /*
181 : * If this is the first call (*context_handle is NULL), we must
182 : * parse the input token to figure out the mechanism to use.
183 : */
184 72865 : if (*context_handle == GSS_C_NO_CONTEXT) {
185 : gss_OID_desc mech_oid;
186 :
187 44781 : major_status = choose_mech(input_token, &mech_oid);
188 44781 : if (major_status != GSS_S_COMPLETE)
189 4 : return major_status;
190 :
191 : /*
192 : * Now that we have a mechanism, we can find the
193 : * implementation.
194 : */
195 44779 : ctx = malloc(sizeof(struct _gss_context));
196 44779 : if (!ctx) {
197 0 : *minor_status = ENOMEM;
198 0 : return (GSS_S_DEFECTIVE_TOKEN);
199 : }
200 44779 : memset(ctx, 0, sizeof(struct _gss_context));
201 44779 : m = ctx->gc_mech = __gss_get_mechanism(&mech_oid);
202 44779 : if (!m) {
203 0 : free(ctx);
204 0 : return (GSS_S_BAD_MECH);
205 : }
206 44779 : *context_handle = (gss_ctx_id_t) ctx;
207 : } else {
208 28084 : m = ctx->gc_mech;
209 : }
210 :
211 72863 : if (cred) {
212 72863 : HEIM_SLIST_FOREACH(mc, &cred->gc_mc, gmc_link)
213 72863 : if (mc->gmc_mech == m)
214 72029 : break;
215 72863 : if (!mc) {
216 0 : gss_delete_sec_context(&junk, context_handle, NULL);
217 0 : return (GSS_S_BAD_MECH);
218 : }
219 72863 : acceptor_mc = mc->gmc_cred;
220 : } else {
221 0 : acceptor_mc = GSS_C_NO_CREDENTIAL;
222 : }
223 72863 : delegated_mc = GSS_C_NO_CREDENTIAL;
224 :
225 72863 : mech_ret_flags = 0;
226 72863 : major_status = m->gm_accept_sec_context(minor_status,
227 : &ctx->gc_ctx,
228 : acceptor_mc,
229 : input_token,
230 : input_chan_bindings,
231 : &src_mn,
232 : &mech_ret_type,
233 : output_token,
234 : &mech_ret_flags,
235 : time_rec,
236 : &delegated_mc);
237 72863 : if (major_status != GSS_S_COMPLETE &&
238 : major_status != GSS_S_CONTINUE_NEEDED)
239 : {
240 39 : _gss_mg_error(m, major_status, *minor_status);
241 39 : gss_delete_sec_context(&junk, context_handle, NULL);
242 39 : return (major_status);
243 : }
244 :
245 72824 : if (mech_type)
246 72824 : *mech_type = mech_ret_type;
247 :
248 145648 : if (src_name && src_mn) {
249 : /*
250 : * Make a new name and mark it as an MN.
251 : */
252 72824 : struct _gss_name *name = _gss_make_name(m, src_mn);
253 :
254 72824 : if (!name) {
255 0 : m->gm_release_name(minor_status, &src_mn);
256 0 : gss_delete_sec_context(&junk, context_handle, NULL);
257 0 : return (GSS_S_FAILURE);
258 : }
259 72824 : *src_name = (gss_name_t) name;
260 0 : } else if (src_mn) {
261 0 : m->gm_release_name(minor_status, &src_mn);
262 : }
263 :
264 72824 : if (mech_ret_flags & GSS_C_DELEG_FLAG) {
265 42518 : if (!delegated_cred_handle) {
266 0 : m->gm_release_cred(minor_status, &delegated_mc);
267 0 : mech_ret_flags &=
268 : ~(GSS_C_DELEG_FLAG|GSS_C_DELEG_POLICY_FLAG);
269 42518 : } else if (gss_oid_equal(mech_ret_type, &m->gm_mech_oid) == 0) {
270 : /*
271 : * If the returned mech_type is not the same
272 : * as the mech, assume its pseudo mech type
273 : * and the returned type is already a
274 : * mech-glue object
275 : */
276 0 : *delegated_cred_handle = delegated_mc;
277 :
278 42518 : } else if (delegated_mc) {
279 : struct _gss_cred *dcred;
280 : struct _gss_mechanism_cred *dmc;
281 :
282 42166 : dcred = malloc(sizeof(struct _gss_cred));
283 42166 : if (!dcred) {
284 0 : *minor_status = ENOMEM;
285 0 : gss_delete_sec_context(&junk, context_handle, NULL);
286 0 : return (GSS_S_FAILURE);
287 : }
288 42166 : HEIM_SLIST_INIT(&dcred->gc_mc);
289 42166 : dmc = malloc(sizeof(struct _gss_mechanism_cred));
290 42166 : if (!dmc) {
291 0 : free(dcred);
292 0 : *minor_status = ENOMEM;
293 0 : gss_delete_sec_context(&junk, context_handle, NULL);
294 0 : return (GSS_S_FAILURE);
295 : }
296 42166 : dmc->gmc_mech = m;
297 42166 : dmc->gmc_mech_oid = &m->gm_mech_oid;
298 42166 : dmc->gmc_cred = delegated_mc;
299 42166 : HEIM_SLIST_INSERT_HEAD(&dcred->gc_mc, dmc, gmc_link);
300 :
301 42166 : *delegated_cred_handle = (gss_cred_id_t) dcred;
302 : }
303 : }
304 :
305 72824 : if (ret_flags)
306 72824 : *ret_flags = mech_ret_flags;
307 71990 : return (major_status);
308 : }
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