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
26 * $FreeBSD: src/lib/libgssapi/gss_accept_sec_context.c,v 1.1 2005/12/29 14:40:20 dfr Exp $
29 #include "mech_locl.h"
30 RCSID("$Id: gss_accept_sec_context.c 22071 2007-11-14 20:04:50Z lha $");
33 parse_header(const gss_buffer_t input_token, gss_OID mech_oid)
35 unsigned char *p = input_token->value;
36 size_t len = input_token->length;
40 * Token must start with [APPLICATION 0] SEQUENCE.
41 * But if it doesn't assume it is DCE-STYLE Kerberos!
44 return (GSS_S_DEFECTIVE_TOKEN);
50 * Decode the length and make sure it agrees with the
54 return (GSS_S_DEFECTIVE_TOKEN);
55 if ((*p & 0x80) == 0) {
64 return (GSS_S_DEFECTIVE_TOKEN);
74 return (GSS_S_DEFECTIVE_TOKEN);
77 * Decode the OID for the mechanism. Simplify life by
78 * assuming that the OID length is less than 128 bytes.
80 if (len < 2 || *p != 0x06)
81 return (GSS_S_DEFECTIVE_TOKEN);
82 if ((p[1] & 0x80) || p[1] > (len - 2))
83 return (GSS_S_DEFECTIVE_TOKEN);
84 mech_oid->length = p[1];
87 mech_oid->elements = p;
89 return GSS_S_COMPLETE;
92 static gss_OID_desc krb5_mechanism =
93 {9, rk_UNCONST("\x2a\x86\x48\x86\xf7\x12\x01\x02\x02")};
94 static gss_OID_desc ntlm_mechanism =
95 {10, rk_UNCONST("\x2b\x06\x01\x04\x01\x82\x37\x02\x02\x0a")};
96 static gss_OID_desc spnego_mechanism =
97 {6, rk_UNCONST("\x2b\x06\x01\x05\x05\x02")};
100 choose_mech(const gss_buffer_t input, gss_OID mech_oid)
105 * First try to parse the gssapi token header and see if it's a
106 * correct header, use that in the first hand.
109 status = parse_header(input, mech_oid);
110 if (status == GSS_S_COMPLETE)
111 return GSS_S_COMPLETE;
114 * Lets guess what mech is really is, callback function to mech ??
117 if (input->length > 8 &&
118 memcmp((const char *)input->value, "NTLMSSP\x00", 8) == 0)
120 *mech_oid = ntlm_mechanism;
121 return GSS_S_COMPLETE;
122 } else if (input->length != 0 &&
123 ((const char *)input->value)[0] == 0x6E)
125 /* Could be a raw AP-REQ (check for APPLICATION tag) */
126 *mech_oid = krb5_mechanism;
127 return GSS_S_COMPLETE;
128 } else if (input->length == 0) {
130 * There is the a wierd mode of SPNEGO (in CIFS and
131 * SASL GSS-SPENGO where the first token is zero
132 * length and the acceptor returns a mech_list, lets
133 * hope that is what is happening now.
135 *mech_oid = spnego_mechanism;
136 return GSS_S_COMPLETE;
142 OM_uint32 gss_accept_sec_context(OM_uint32 *minor_status,
143 gss_ctx_id_t *context_handle,
144 const gss_cred_id_t acceptor_cred_handle,
145 const gss_buffer_t input_token,
146 const gss_channel_bindings_t input_chan_bindings,
147 gss_name_t *src_name,
149 gss_buffer_t output_token,
150 OM_uint32 *ret_flags,
152 gss_cred_id_t *delegated_cred_handle)
154 OM_uint32 major_status, mech_ret_flags;
155 gssapi_mech_interface m;
156 struct _gss_context *ctx = (struct _gss_context *) *context_handle;
157 struct _gss_cred *cred = (struct _gss_cred *) acceptor_cred_handle;
158 struct _gss_mechanism_cred *mc;
159 gss_cred_id_t acceptor_mc, delegated_mc;
165 *src_name = GSS_C_NO_NAME;
167 *mech_type = GSS_C_NO_OID;
172 if (delegated_cred_handle)
173 *delegated_cred_handle = GSS_C_NO_CREDENTIAL;
174 _mg_buffer_zero(output_token);
178 * If this is the first call (*context_handle is NULL), we must
179 * parse the input token to figure out the mechanism to use.
181 if (*context_handle == GSS_C_NO_CONTEXT) {
182 gss_OID_desc mech_oid;
184 major_status = choose_mech(input_token, &mech_oid);
185 if (major_status != GSS_S_COMPLETE)
189 * Now that we have a mechanism, we can find the
192 ctx = malloc(sizeof(struct _gss_context));
194 *minor_status = ENOMEM;
195 return (GSS_S_DEFECTIVE_TOKEN);
197 memset(ctx, 0, sizeof(struct _gss_context));
198 m = ctx->gc_mech = __gss_get_mechanism(&mech_oid);
201 return (GSS_S_BAD_MECH);
210 SLIST_FOREACH(mc, &cred->gc_mc, gmc_link)
211 if (mc->gmc_mech == m)
214 return (GSS_S_BAD_MECH);
215 acceptor_mc = mc->gmc_cred;
217 acceptor_mc = GSS_C_NO_CREDENTIAL;
219 delegated_mc = GSS_C_NO_CREDENTIAL;
222 major_status = m->gm_accept_sec_context(minor_status,
233 if (major_status != GSS_S_COMPLETE &&
234 major_status != GSS_S_CONTINUE_NEEDED)
236 _gss_mg_error(m, major_status, *minor_status);
237 return (major_status);
240 if (src_name && src_mn) {
242 * Make a new name and mark it as an MN.
244 struct _gss_name *name = _gss_make_name(m, src_mn);
247 m->gm_release_name(minor_status, &src_mn);
248 return (GSS_S_FAILURE);
250 *src_name = (gss_name_t) name;
252 m->gm_release_name(minor_status, &src_mn);
255 if (mech_ret_flags & GSS_C_DELEG_FLAG) {
256 if (!delegated_cred_handle) {
257 m->gm_release_cred(minor_status, &delegated_mc);
258 *ret_flags &= ~GSS_C_DELEG_FLAG;
259 } else if (delegated_mc) {
260 struct _gss_cred *dcred;
261 struct _gss_mechanism_cred *dmc;
263 dcred = malloc(sizeof(struct _gss_cred));
265 *minor_status = ENOMEM;
266 return (GSS_S_FAILURE);
268 SLIST_INIT(&dcred->gc_mc);
269 dmc = malloc(sizeof(struct _gss_mechanism_cred));
272 *minor_status = ENOMEM;
273 return (GSS_S_FAILURE);
276 dmc->gmc_mech_oid = &m->gm_mech_oid;
277 dmc->gmc_cred = delegated_mc;
278 SLIST_INSERT_HEAD(&dcred->gc_mc, dmc, gmc_link);
280 *delegated_cred_handle = (gss_cred_id_t) dcred;
285 *ret_flags = mech_ret_flags;
286 *context_handle = (gss_ctx_id_t) ctx;
287 return (major_status);