gss_accept_sec_context.c revision 178692
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: head/lib/libgssapi/gss_accept_sec_context.c 178692 2008-04-30 11:29:22Z dfr $ 27 */ 28 29#include <gssapi/gssapi.h> 30#include <stdlib.h> 31#include <string.h> 32#include <errno.h> 33 34#include "mech_switch.h" 35#include "context.h" 36#include "cred.h" 37#include "name.h" 38 39OM_uint32 gss_accept_sec_context(OM_uint32 *minor_status, 40 gss_ctx_id_t *context_handle, 41 const gss_cred_id_t acceptor_cred_handle, 42 const gss_buffer_t input_token, 43 const gss_channel_bindings_t input_chan_bindings, 44 gss_name_t *src_name, 45 gss_OID *mech_type, 46 gss_buffer_t output_token, 47 OM_uint32 *ret_flags, 48 OM_uint32 *time_rec, 49 gss_cred_id_t *delegated_cred_handle) 50{ 51 OM_uint32 major_status, mech_ret_flags; 52 struct _gss_mech_switch *m; 53 struct _gss_context *ctx = (struct _gss_context *) *context_handle; 54 struct _gss_cred *cred = (struct _gss_cred *) acceptor_cred_handle; 55 struct _gss_mechanism_cred *mc; 56 gss_cred_id_t acceptor_mc, delegated_mc; 57 gss_name_t src_mn; 58 int allocated_ctx; 59 60 *minor_status = 0; 61 if (src_name) *src_name = 0; 62 if (mech_type) *mech_type = 0; 63 if (ret_flags) *ret_flags = 0; 64 if (time_rec) *time_rec = 0; 65 if (delegated_cred_handle) *delegated_cred_handle = 0; 66 output_token->length = 0; 67 output_token->value = 0; 68 69 /* 70 * If this is the first call (*context_handle is NULL), we must 71 * parse the input token to figure out the mechanism to use. 72 */ 73 if (*context_handle == GSS_C_NO_CONTEXT) { 74 unsigned char *p = input_token->value; 75 size_t len = input_token->length; 76 size_t a, b; 77 gss_OID_desc mech_oid; 78 79 /* 80 * Token must start with [APPLICATION 0] SEQUENCE. 81 */ 82 if (len == 0 || *p != 0x60) 83 return (GSS_S_DEFECTIVE_TOKEN); 84 p++; 85 len--; 86 87 /* 88 * Decode the length and make sure it agrees with the 89 * token length. 90 */ 91 if (len == 0) 92 return (GSS_S_DEFECTIVE_TOKEN); 93 if ((*p & 0x80) == 0) { 94 a = *p; 95 p++; 96 len--; 97 } else { 98 b = *p & 0x7f; 99 p++; 100 len--; 101 if (len < b) 102 return (GSS_S_DEFECTIVE_TOKEN); 103 a = 0; 104 while (b) { 105 a = (a << 8) | *p; 106 p++; 107 len--; 108 b--; 109 } 110 } 111 if (a != len) 112 return (GSS_S_DEFECTIVE_TOKEN); 113 114 /* 115 * Decode the OID for the mechanism. Simplify life by 116 * assuming that the OID length is less than 128 bytes. 117 */ 118 if (len < 2 || *p != 0x06) 119 return (GSS_S_DEFECTIVE_TOKEN); 120 if ((p[1] & 0x80) || p[1] > (len - 2)) 121 return (GSS_S_DEFECTIVE_TOKEN); 122 mech_oid.length = p[1]; 123 p += 2; 124 len -= 2; 125 mech_oid.elements = p; 126 127 /* 128 * Now that we have a mechanism, we can find the 129 * implementation. 130 */ 131 ctx = malloc(sizeof(struct _gss_context)); 132 if (!ctx) { 133 *minor_status = ENOMEM; 134 return (GSS_S_DEFECTIVE_TOKEN); 135 } 136 memset(ctx, 0, sizeof(struct _gss_context)); 137 m = ctx->gc_mech = _gss_find_mech_switch(&mech_oid); 138 if (!m) { 139 free(ctx); 140 return (GSS_S_BAD_MECH); 141 } 142 allocated_ctx = 1; 143 } else { 144 m = ctx->gc_mech; 145 allocated_ctx = 0; 146 } 147 148 if (cred) { 149 SLIST_FOREACH(mc, &cred->gc_mc, gmc_link) 150 if (mc->gmc_mech == m) 151 break; 152 if (!mc) 153 return (GSS_S_BAD_MECH); 154 acceptor_mc = mc->gmc_cred; 155 } else { 156 acceptor_mc = GSS_C_NO_CREDENTIAL; 157 } 158 delegated_mc = GSS_C_NO_CREDENTIAL; 159 160 major_status = m->gm_accept_sec_context(minor_status, 161 &ctx->gc_ctx, 162 acceptor_mc, 163 input_token, 164 input_chan_bindings, 165 &src_mn, 166 mech_type, 167 output_token, 168 &mech_ret_flags, 169 time_rec, 170 &delegated_mc); 171 if (major_status != GSS_S_COMPLETE && 172 major_status != GSS_S_CONTINUE_NEEDED) 173 return (major_status); 174 175 if (!src_name) { 176 m->gm_release_name(minor_status, &src_mn); 177 } else { 178 /* 179 * Make a new name and mark it as an MN. 180 */ 181 struct _gss_name *name = _gss_make_name(m, src_mn); 182 183 if (!name) { 184 m->gm_release_name(minor_status, &src_mn); 185 return (GSS_S_FAILURE); 186 } 187 *src_name = (gss_name_t) name; 188 } 189 190 if (delegated_mc == GSS_C_NO_CREDENTIAL) 191 mech_ret_flags &= ~GSS_C_DELEG_FLAG; 192 193 if (mech_ret_flags & GSS_C_DELEG_FLAG) { 194 if (!delegated_cred_handle) { 195 m->gm_release_cred(minor_status, &delegated_mc); 196 mech_ret_flags &= ~GSS_C_DELEG_FLAG; 197 } else { 198 struct _gss_cred *cred; 199 struct _gss_mechanism_cred *mc; 200 201 cred = malloc(sizeof(struct _gss_cred)); 202 if (!cred) { 203 *minor_status = ENOMEM; 204 return (GSS_S_FAILURE); 205 } 206 SLIST_INIT(&cred->gc_mc); 207 mc = malloc(sizeof(struct _gss_mechanism_cred)); 208 if (!mc) { 209 free(cred); 210 *minor_status = ENOMEM; 211 return (GSS_S_FAILURE); 212 } 213 m->gm_inquire_cred(minor_status, delegated_mc, 214 0, 0, &cred->gc_usage, 0); 215 mc->gmc_mech = m; 216 mc->gmc_mech_oid = &m->gm_mech_oid; 217 mc->gmc_cred = delegated_mc; 218 SLIST_INSERT_HEAD(&cred->gc_mc, mc, gmc_link); 219 220 *delegated_cred_handle = (gss_cred_id_t) cred; 221 } 222 } 223 224 if (ret_flags) 225 *ret_flags = mech_ret_flags; 226 *context_handle = (gss_ctx_id_t) ctx; 227 return (major_status); 228} 229