2 * Copyright (c) 2005 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #include <gssapi/gssapi.h>
34 #include "mech_switch.h"
41 parse_header(const gss_buffer_t input_token, gss_OID mech_oid)
43 unsigned char *p = input_token->value;
44 size_t len = input_token->length;
48 * Token must start with [APPLICATION 0] SEQUENCE.
49 * But if it doesn't assume it is DCE-STYLE Kerberos!
52 return (GSS_S_DEFECTIVE_TOKEN);
58 * Decode the length and make sure it agrees with the
62 return (GSS_S_DEFECTIVE_TOKEN);
63 if ((*p & 0x80) == 0) {
72 return (GSS_S_DEFECTIVE_TOKEN);
82 return (GSS_S_DEFECTIVE_TOKEN);
85 * Decode the OID for the mechanism. Simplify life by
86 * assuming that the OID length is less than 128 bytes.
88 if (len < 2 || *p != 0x06)
89 return (GSS_S_DEFECTIVE_TOKEN);
90 if ((p[1] & 0x80) || p[1] > (len - 2))
91 return (GSS_S_DEFECTIVE_TOKEN);
92 mech_oid->length = p[1];
95 mech_oid->elements = p;
97 return (GSS_S_COMPLETE);
100 static gss_OID_desc krb5_mechanism =
101 {9, (void *)(uintptr_t) "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02"};
102 static gss_OID_desc ntlm_mechanism =
103 {10, (void *)(uintptr_t) "\x2b\x06\x01\x04\x01\x82\x37\x02\x02\x0a"};
104 static gss_OID_desc spnego_mechanism =
105 {6, (void *)(uintptr_t) "\x2b\x06\x01\x05\x05\x02"};
108 choose_mech(const gss_buffer_t input, gss_OID mech_oid)
113 * First try to parse the gssapi token header and see if it's a
114 * correct header, use that in the first hand.
117 status = parse_header(input, mech_oid);
118 if (status == GSS_S_COMPLETE)
119 return (GSS_S_COMPLETE);
122 * Lets guess what mech is really is, callback function to mech ??
125 if (input->length > 8 &&
126 memcmp((const char *)input->value, "NTLMSSP\x00", 8) == 0)
128 *mech_oid = ntlm_mechanism;
129 return (GSS_S_COMPLETE);
130 } else if (input->length != 0 &&
131 ((const char *)input->value)[0] == 0x6E)
133 /* Could be a raw AP-REQ (check for APPLICATION tag) */
134 *mech_oid = krb5_mechanism;
135 return (GSS_S_COMPLETE);
136 } else if (input->length == 0) {
138 * There is the a wierd mode of SPNEGO (in CIFS and
139 * SASL GSS-SPENGO where the first token is zero
140 * length and the acceptor returns a mech_list, lets
141 * hope that is what is happening now.
143 *mech_oid = spnego_mechanism;
144 return (GSS_S_COMPLETE);
149 OM_uint32 gss_accept_sec_context(OM_uint32 *minor_status,
150 gss_ctx_id_t *context_handle,
151 const gss_cred_id_t acceptor_cred_handle,
152 const gss_buffer_t input_token,
153 const gss_channel_bindings_t input_chan_bindings,
154 gss_name_t *src_name,
156 gss_buffer_t output_token,
157 OM_uint32 *ret_flags,
159 gss_cred_id_t *delegated_cred_handle)
161 OM_uint32 major_status, mech_ret_flags;
162 struct _gss_mech_switch *m;
163 struct _gss_context *ctx = (struct _gss_context *) *context_handle;
164 struct _gss_cred *cred = (struct _gss_cred *) acceptor_cred_handle;
165 struct _gss_mechanism_cred *mc;
166 gss_cred_id_t acceptor_mc, delegated_mc;
172 *src_name = GSS_C_NO_NAME;
174 *mech_type = GSS_C_NO_OID;
179 if (delegated_cred_handle)
180 *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
181 _gss_buffer_zero(output_token);
184 * If this is the first call (*context_handle is NULL), we must
185 * parse the input token to figure out the mechanism to use.
187 if (*context_handle == GSS_C_NO_CONTEXT) {
188 gss_OID_desc mech_oid;
190 major_status = choose_mech(input_token, &mech_oid);
191 if (major_status != GSS_S_COMPLETE)
192 return (major_status);
195 * Now that we have a mechanism, we can find the
198 ctx = malloc(sizeof(struct _gss_context));
200 *minor_status = ENOMEM;
201 return (GSS_S_DEFECTIVE_TOKEN);
203 memset(ctx, 0, sizeof(struct _gss_context));
204 m = ctx->gc_mech = _gss_find_mech_switch(&mech_oid);
207 return (GSS_S_BAD_MECH);
216 SLIST_FOREACH(mc, &cred->gc_mc, gmc_link)
217 if (mc->gmc_mech == m)
220 return (GSS_S_BAD_MECH);
221 acceptor_mc = mc->gmc_cred;
223 acceptor_mc = GSS_C_NO_CREDENTIAL;
225 delegated_mc = GSS_C_NO_CREDENTIAL;
228 major_status = m->gm_accept_sec_context(minor_status,
239 if (major_status != GSS_S_COMPLETE &&
240 major_status != GSS_S_CONTINUE_NEEDED) {
241 _gss_mg_error(m, major_status, *minor_status);
242 return (major_status);
245 if (src_name && src_mn) {
247 * Make a new name and mark it as an MN.
249 struct _gss_name *name = _gss_make_name(m, src_mn);
252 m->gm_release_name(minor_status, &src_mn);
253 return (GSS_S_FAILURE);
255 *src_name = (gss_name_t) name;
257 m->gm_release_name(minor_status, &src_mn);
260 if (delegated_mc == GSS_C_NO_CREDENTIAL)
261 mech_ret_flags &= ~GSS_C_DELEG_FLAG;
263 if (mech_ret_flags & GSS_C_DELEG_FLAG) {
264 if (!delegated_cred_handle) {
265 m->gm_release_cred(minor_status, &delegated_mc);
266 mech_ret_flags &= ~GSS_C_DELEG_FLAG;
268 struct _gss_cred *dcred;
269 struct _gss_mechanism_cred *dmc;
271 dcred = malloc(sizeof(struct _gss_cred));
273 *minor_status = ENOMEM;
274 return (GSS_S_FAILURE);
276 SLIST_INIT(&dcred->gc_mc);
277 dmc = malloc(sizeof(struct _gss_mechanism_cred));
280 *minor_status = ENOMEM;
281 return (GSS_S_FAILURE);
284 dmc->gmc_mech_oid = &m->gm_mech_oid;
285 dmc->gmc_cred = delegated_mc;
286 SLIST_INSERT_HEAD(&dcred->gc_mc, dmc, gmc_link);
288 *delegated_cred_handle = (gss_cred_id_t) dcred;
293 *ret_flags = mech_ret_flags;
294 *context_handle = (gss_ctx_id_t) ctx;
295 return (major_status);