1/* $NetBSD: 8003.c,v 1.2 2017/01/28 21:31:46 christos Exp $ */ 2 3/* 4 * Copyright (c) 1997 - 2003 Kungliga Tekniska H��gskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include "gsskrb5_locl.h" 37 38krb5_error_code 39_gsskrb5_encode_om_uint32(OM_uint32 n, u_char *p) 40{ 41 p[0] = (n >> 0) & 0xFF; 42 p[1] = (n >> 8) & 0xFF; 43 p[2] = (n >> 16) & 0xFF; 44 p[3] = (n >> 24) & 0xFF; 45 return 0; 46} 47 48krb5_error_code 49_gsskrb5_encode_be_om_uint32(OM_uint32 n, u_char *p) 50{ 51 p[0] = (n >> 24) & 0xFF; 52 p[1] = (n >> 16) & 0xFF; 53 p[2] = (n >> 8) & 0xFF; 54 p[3] = (n >> 0) & 0xFF; 55 return 0; 56} 57 58krb5_error_code 59_gsskrb5_decode_om_uint32(const void *ptr, OM_uint32 *n) 60{ 61 const u_char *p = ptr; 62 *n = (p[0] << 0) | (p[1] << 8) | (p[2] << 16) | (p[3] << 24); 63 return 0; 64} 65 66krb5_error_code 67_gsskrb5_decode_be_om_uint32(const void *ptr, OM_uint32 *n) 68{ 69 const u_char *p = ptr; 70 *n = (p[0] <<24) | (p[1] << 16) | (p[2] << 8) | (p[3] << 0); 71 return 0; 72} 73 74static krb5_error_code 75hash_input_chan_bindings (const gss_channel_bindings_t b, 76 u_char *p) 77{ 78 u_char num[4]; 79 EVP_MD_CTX *ctx; 80 81 ctx = EVP_MD_CTX_create(); 82 EVP_DigestInit_ex(ctx, EVP_md5(), NULL); 83 84 _gsskrb5_encode_om_uint32 (b->initiator_addrtype, num); 85 EVP_DigestUpdate(ctx, num, sizeof(num)); 86 _gsskrb5_encode_om_uint32 (b->initiator_address.length, num); 87 EVP_DigestUpdate(ctx, num, sizeof(num)); 88 if (b->initiator_address.length) 89 EVP_DigestUpdate(ctx, 90 b->initiator_address.value, 91 b->initiator_address.length); 92 _gsskrb5_encode_om_uint32 (b->acceptor_addrtype, num); 93 EVP_DigestUpdate(ctx, num, sizeof(num)); 94 _gsskrb5_encode_om_uint32 (b->acceptor_address.length, num); 95 EVP_DigestUpdate(ctx, num, sizeof(num)); 96 if (b->acceptor_address.length) 97 EVP_DigestUpdate(ctx, 98 b->acceptor_address.value, 99 b->acceptor_address.length); 100 _gsskrb5_encode_om_uint32 (b->application_data.length, num); 101 EVP_DigestUpdate(ctx, num, sizeof(num)); 102 if (b->application_data.length) 103 EVP_DigestUpdate(ctx, 104 b->application_data.value, 105 b->application_data.length); 106 EVP_DigestFinal_ex(ctx, p, NULL); 107 EVP_MD_CTX_destroy(ctx); 108 109 return 0; 110} 111 112/* 113 * create a checksum over the chanel bindings in 114 * `input_chan_bindings', `flags' and `fwd_data' and return it in 115 * `result' 116 */ 117 118OM_uint32 119_gsskrb5_create_8003_checksum ( 120 OM_uint32 *minor_status, 121 const gss_channel_bindings_t input_chan_bindings, 122 OM_uint32 flags, 123 const krb5_data *fwd_data, 124 Checksum *result) 125{ 126 u_char *p; 127 128 /* 129 * see rfc1964 (section 1.1.1 (Initial Token), and the checksum value 130 * field's format) */ 131 result->cksumtype = CKSUMTYPE_GSSAPI; 132 if (fwd_data->length > 0 && (flags & GSS_C_DELEG_FLAG)) 133 result->checksum.length = 24 + 4 + fwd_data->length; 134 else 135 result->checksum.length = 24; 136 result->checksum.data = malloc (result->checksum.length); 137 if (result->checksum.data == NULL) { 138 *minor_status = ENOMEM; 139 return GSS_S_FAILURE; 140 } 141 142 p = result->checksum.data; 143 _gsskrb5_encode_om_uint32 (16, p); 144 p += 4; 145 if (input_chan_bindings == GSS_C_NO_CHANNEL_BINDINGS) { 146 memset (p, 0, 16); 147 } else { 148 hash_input_chan_bindings (input_chan_bindings, p); 149 } 150 p += 16; 151 _gsskrb5_encode_om_uint32 (flags, p); 152 p += 4; 153 154 if (fwd_data->length > 0 && (flags & GSS_C_DELEG_FLAG)) { 155 156 *p++ = (1 >> 0) & 0xFF; /* DlgOpt */ /* == 1 */ 157 *p++ = (1 >> 8) & 0xFF; /* DlgOpt */ /* == 0 */ 158 *p++ = (fwd_data->length >> 0) & 0xFF; /* Dlgth */ 159 *p++ = (fwd_data->length >> 8) & 0xFF; /* Dlgth */ 160 memcpy(p, (unsigned char *) fwd_data->data, fwd_data->length); 161 162 /* p += fwd_data->length; */ /* commented out to quiet warning */ 163 } 164 165 return GSS_S_COMPLETE; 166} 167 168/* 169 * verify the checksum in `cksum' over `input_chan_bindings' 170 * returning `flags' and `fwd_data' 171 */ 172 173OM_uint32 174_gsskrb5_verify_8003_checksum( 175 OM_uint32 *minor_status, 176 const gss_channel_bindings_t input_chan_bindings, 177 const Checksum *cksum, 178 OM_uint32 *flags, 179 krb5_data *fwd_data) 180{ 181 unsigned char hash[16]; 182 unsigned char *p; 183 OM_uint32 length; 184 int DlgOpt; 185 static unsigned char zeros[16]; 186 187 /* XXX should handle checksums > 24 bytes */ 188 if(cksum->cksumtype != CKSUMTYPE_GSSAPI || cksum->checksum.length < 24) { 189 *minor_status = 0; 190 return GSS_S_BAD_BINDINGS; 191 } 192 193 p = cksum->checksum.data; 194 _gsskrb5_decode_om_uint32(p, &length); 195 if(length != sizeof(hash)) { 196 *minor_status = 0; 197 return GSS_S_BAD_BINDINGS; 198 } 199 200 p += 4; 201 202 if (input_chan_bindings != GSS_C_NO_CHANNEL_BINDINGS 203 && memcmp(p, zeros, sizeof(zeros)) != 0) { 204 if(hash_input_chan_bindings(input_chan_bindings, hash) != 0) { 205 *minor_status = 0; 206 return GSS_S_BAD_BINDINGS; 207 } 208 if(ct_memcmp(hash, p, sizeof(hash)) != 0) { 209 *minor_status = 0; 210 return GSS_S_BAD_BINDINGS; 211 } 212 } 213 214 p += sizeof(hash); 215 216 _gsskrb5_decode_om_uint32(p, flags); 217 p += 4; 218 219 if (cksum->checksum.length > 24 && (*flags & GSS_C_DELEG_FLAG)) { 220 if(cksum->checksum.length < 28) { 221 *minor_status = 0; 222 return GSS_S_BAD_BINDINGS; 223 } 224 225 DlgOpt = (p[0] << 0) | (p[1] << 8); 226 p += 2; 227 if (DlgOpt != 1) { 228 *minor_status = 0; 229 return GSS_S_BAD_BINDINGS; 230 } 231 232 fwd_data->length = (p[0] << 0) | (p[1] << 8); 233 p += 2; 234 if(cksum->checksum.length < 28 + fwd_data->length) { 235 *minor_status = 0; 236 return GSS_S_BAD_BINDINGS; 237 } 238 fwd_data->data = malloc(fwd_data->length); 239 if (fwd_data->data == NULL) { 240 *minor_status = ENOMEM; 241 return GSS_S_FAILURE; 242 } 243 memcpy(fwd_data->data, p, fwd_data->length); 244 } 245 246 return GSS_S_COMPLETE; 247} 248