1 /* $NetBSD: gss_accept_sec_context.c,v 1.2 2017/01/28 21:31:46 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2005 Doug Rabson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: src/lib/libgssapi/gss_accept_sec_context.c,v 1.1 2005/12/29 14:40:20 dfr Exp $ 29 */ 30 31 #include "mech_locl.h" 32 33 static OM_uint32 34 parse_header(const gss_buffer_t input_token, gss_OID mech_oid) 35 { 36 unsigned char *p = input_token->value; 37 size_t len = input_token->length; 38 size_t a, b; 39 40 /* 41 * Token must start with [APPLICATION 0] SEQUENCE. 42 * But if it doesn't assume it is DCE-STYLE Kerberos! 43 */ 44 if (len == 0) 45 return (GSS_S_DEFECTIVE_TOKEN); 46 47 p++; 48 len--; 49 50 /* 51 * Decode the length and make sure it agrees with the 52 * token length. 53 */ 54 if (len == 0) 55 return (GSS_S_DEFECTIVE_TOKEN); 56 if ((*p & 0x80) == 0) { 57 a = *p; 58 p++; 59 len--; 60 } else { 61 b = *p & 0x7f; 62 p++; 63 len--; 64 if (len < b) 65 return (GSS_S_DEFECTIVE_TOKEN); 66 a = 0; 67 while (b) { 68 a = (a << 8) | *p; 69 p++; 70 len--; 71 b--; 72 } 73 } 74 if (a != len) 75 return (GSS_S_DEFECTIVE_TOKEN); 76 77 /* 78 * Decode the OID for the mechanism. Simplify life by 79 * assuming that the OID length is less than 128 bytes. 80 */ 81 if (len < 2 || *p != 0x06) 82 return (GSS_S_DEFECTIVE_TOKEN); 83 if ((p[1] & 0x80) || p[1] > (len - 2)) 84 return (GSS_S_DEFECTIVE_TOKEN); 85 mech_oid->length = p[1]; 86 p += 2; 87 len -= 2; 88 mech_oid->elements = p; 89 90 return GSS_S_COMPLETE; 91 } 92 93 static gss_OID_desc krb5_mechanism = 94 {9, rk_UNCONST("\x2a\x86\x48\x86\xf7\x12\x01\x02\x02")}; 95 static gss_OID_desc ntlm_mechanism = 96 {10, rk_UNCONST("\x2b\x06\x01\x04\x01\x82\x37\x02\x02\x0a")}; 97 static gss_OID_desc spnego_mechanism = 98 {6, rk_UNCONST("\x2b\x06\x01\x05\x05\x02")}; 99 100 static OM_uint32 101 choose_mech(const gss_buffer_t input, gss_OID mech_oid) 102 { 103 OM_uint32 status; 104 105 /* 106 * First try to parse the gssapi token header and see if it's a 107 * correct header, use that in the first hand. 108 */ 109 110 status = parse_header(input, mech_oid); 111 if (status == GSS_S_COMPLETE) 112 return GSS_S_COMPLETE; 113 114 /* 115 * Lets guess what mech is really is, callback function to mech ?? 116 */ 117 118 if (input->length > 8 && 119 memcmp((const char *)input->value, "NTLMSSP\x00", 8) == 0) 120 { 121 *mech_oid = ntlm_mechanism; 122 return GSS_S_COMPLETE; 123 } else if (input->length != 0 && 124 ((const char *)input->value)[0] == 0x6E) 125 { 126 /* Could be a raw AP-REQ (check for APPLICATION tag) */ 127 *mech_oid = krb5_mechanism; 128 return GSS_S_COMPLETE; 129 } else if (input->length == 0) { 130 /* 131 * There is the a wierd mode of SPNEGO (in CIFS and 132 * SASL GSS-SPENGO where the first token is zero 133 * length and the acceptor returns a mech_list, lets 134 * hope that is what is happening now. 135 * 136 * http://msdn.microsoft.com/en-us/library/cc213114.aspx 137 * "NegTokenInit2 Variation for Server-Initiation" 138 */ 139 *mech_oid = spnego_mechanism; 140 return GSS_S_COMPLETE; 141 } 142 return status; 143 } 144 145 146 GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL 147 gss_accept_sec_context(OM_uint32 *minor_status, 148 gss_ctx_id_t *context_handle, 149 gss_const_cred_id_t acceptor_cred_handle, 150 const gss_buffer_t input_token, 151 const gss_channel_bindings_t input_chan_bindings, 152 gss_name_t *src_name, 153 gss_OID *mech_type, 154 gss_buffer_t output_token, 155 OM_uint32 *ret_flags, 156 OM_uint32 *time_rec, 157 gss_cred_id_t *delegated_cred_handle) 158 { 159 OM_uint32 major_status, mech_ret_flags, junk; 160 gssapi_mech_interface m; 161 struct _gss_context *ctx = (struct _gss_context *) *context_handle; 162 struct _gss_cred *cred = (struct _gss_cred *) acceptor_cred_handle; 163 struct _gss_mechanism_cred *mc; 164 gss_cred_id_t acceptor_mc, delegated_mc; 165 gss_name_t src_mn; 166 gss_OID mech_ret_type = NULL; 167 168 *minor_status = 0; 169 if (src_name) 170 *src_name = GSS_C_NO_NAME; 171 if (mech_type) 172 *mech_type = GSS_C_NO_OID; 173 if (ret_flags) 174 *ret_flags = 0; 175 if (time_rec) 176 *time_rec = 0; 177 if (delegated_cred_handle) 178 *delegated_cred_handle = GSS_C_NO_CREDENTIAL; 179 _mg_buffer_zero(output_token); 180 181 182 /* 183 * If this is the first call (*context_handle is NULL), we must 184 * parse the input token to figure out the mechanism to use. 185 */ 186 if (*context_handle == GSS_C_NO_CONTEXT) { 187 gss_OID_desc mech_oid; 188 189 major_status = choose_mech(input_token, &mech_oid); 190 if (major_status != GSS_S_COMPLETE) 191 return major_status; 192 193 /* 194 * Now that we have a mechanism, we can find the 195 * implementation. 196 */ 197 ctx = malloc(sizeof(struct _gss_context)); 198 if (!ctx) { 199 *minor_status = ENOMEM; 200 return (GSS_S_DEFECTIVE_TOKEN); 201 } 202 memset(ctx, 0, sizeof(struct _gss_context)); 203 m = ctx->gc_mech = __gss_get_mechanism(&mech_oid); 204 if (!m) { 205 free(ctx); 206 return (GSS_S_BAD_MECH); 207 } 208 *context_handle = (gss_ctx_id_t) ctx; 209 } else { 210 m = ctx->gc_mech; 211 } 212 213 if (cred) { 214 HEIM_SLIST_FOREACH(mc, &cred->gc_mc, gmc_link) 215 if (mc->gmc_mech == m) 216 break; 217 if (!mc) { 218 gss_delete_sec_context(&junk, context_handle, NULL); 219 return (GSS_S_BAD_MECH); 220 } 221 acceptor_mc = mc->gmc_cred; 222 } else { 223 acceptor_mc = GSS_C_NO_CREDENTIAL; 224 } 225 delegated_mc = GSS_C_NO_CREDENTIAL; 226 227 mech_ret_flags = 0; 228 major_status = m->gm_accept_sec_context(minor_status, 229 &ctx->gc_ctx, 230 acceptor_mc, 231 input_token, 232 input_chan_bindings, 233 &src_mn, 234 &mech_ret_type, 235 output_token, 236 &mech_ret_flags, 237 time_rec, 238 &delegated_mc); 239 if (major_status != GSS_S_COMPLETE && 240 major_status != GSS_S_CONTINUE_NEEDED) 241 { 242 _gss_mg_error(m, major_status, *minor_status); 243 gss_delete_sec_context(&junk, context_handle, NULL); 244 return (major_status); 245 } 246 247 if (mech_type) 248 *mech_type = mech_ret_type; 249 250 if (src_name && src_mn) { 251 /* 252 * Make a new name and mark it as an MN. 253 */ 254 struct _gss_name *name = _gss_make_name(m, src_mn); 255 256 if (!name) { 257 m->gm_release_name(minor_status, &src_mn); 258 gss_delete_sec_context(&junk, context_handle, NULL); 259 return (GSS_S_FAILURE); 260 } 261 *src_name = (gss_name_t) name; 262 } else if (src_mn) { 263 m->gm_release_name(minor_status, &src_mn); 264 } 265 266 if (mech_ret_flags & GSS_C_DELEG_FLAG) { 267 if (!delegated_cred_handle) { 268 m->gm_release_cred(minor_status, &delegated_mc); 269 mech_ret_flags &= 270 ~(GSS_C_DELEG_FLAG|GSS_C_DELEG_POLICY_FLAG); 271 } else if (gss_oid_equal(mech_ret_type, &m->gm_mech_oid) == 0) { 272 /* 273 * If the returned mech_type is not the same 274 * as the mech, assume its pseudo mech type 275 * and the returned type is already a 276 * mech-glue object 277 */ 278 *delegated_cred_handle = delegated_mc; 279 280 } else if (delegated_mc) { 281 struct _gss_cred *dcred; 282 struct _gss_mechanism_cred *dmc; 283 284 dcred = malloc(sizeof(struct _gss_cred)); 285 if (!dcred) { 286 *minor_status = ENOMEM; 287 gss_delete_sec_context(&junk, context_handle, NULL); 288 return (GSS_S_FAILURE); 289 } 290 HEIM_SLIST_INIT(&dcred->gc_mc); 291 dmc = malloc(sizeof(struct _gss_mechanism_cred)); 292 if (!dmc) { 293 free(dcred); 294 *minor_status = ENOMEM; 295 gss_delete_sec_context(&junk, context_handle, NULL); 296 return (GSS_S_FAILURE); 297 } 298 dmc->gmc_mech = m; 299 dmc->gmc_mech_oid = &m->gm_mech_oid; 300 dmc->gmc_cred = delegated_mc; 301 HEIM_SLIST_INSERT_HEAD(&dcred->gc_mc, dmc, gmc_link); 302 303 *delegated_cred_handle = (gss_cred_id_t) dcred; 304 } 305 } 306 307 if (ret_flags) 308 *ret_flags = mech_ret_flags; 309 return (major_status); 310 } 311
Indexes created Fri Jun 12 00:25:51 UTC 2026