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