lib/krb5/recvauth.c

   1 /*
   2  * Copyright (c) 1997-2007 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 /*
  37  * See `sendauth.c' for the format.
  38  */
  39
  40 static krb5_boolean
  41 match_exact(const void *data, const char *appl_version)
  42 {
  43     return strcmp(data, appl_version) == 0;
  44 }
  45
  46 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  47 krb5_recvauth(krb5_context context,
  48               krb5_auth_context *auth_context,
  49               krb5_pointer p_fd,
  50               const char *appl_version,
  51               krb5_principal server,
  52               int32_t flags,
  53               krb5_keytab keytab,
  54               krb5_ticket **ticket)
  55 {
  56     return krb5_recvauth_match_version(context, auth_context, p_fd,
  57                                        match_exact, appl_version,
  58                                        server, flags,
  59                                        keytab, ticket);
  60 }
  61
  62 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  63 krb5_recvauth_match_version(krb5_context context,
  64                             krb5_auth_context *auth_context,
  65                             krb5_pointer p_fd,
  66                             krb5_boolean (*match_appl_version)(const void *,
  67                                                                const char*),
  68                             const void *match_data,
  69                             krb5_principal server,
  70                             int32_t flags,
  71                             krb5_keytab keytab,
  72                             krb5_ticket **ticket)
  73 {
  74     krb5_error_code ret;
  75     const char *version = KRB5_SENDAUTH_VERSION;
  76     char her_version[sizeof(KRB5_SENDAUTH_VERSION)];
  77     char *her_appl_version;
  78     uint32_t len;
  79     u_char repl;
  80     krb5_data data;
  81     krb5_flags ap_options;
  82     ssize_t n;
  83
  84     /*
  85      * If there are no addresses in auth_context, get them from `fd'.
  86      */
  87
  88     if (*auth_context == NULL) {
  89         ret = krb5_auth_con_init (context, auth_context);
  90         if (ret)
  91             return ret;
  92     }
  93
  94     ret = krb5_auth_con_setaddrs_from_fd (context,
  95                                           *auth_context,
  96                                           p_fd);
  97     if (ret)
  98         return ret;
  99
 100     if(!(flags & KRB5_RECVAUTH_IGNORE_VERSION)) {
 101         n = krb5_net_read (context, p_fd, &len, 4);
 102         if (n < 0) {
 103             ret = errno;
 104             krb5_set_error_message(context, ret, "read: %s", strerror(ret));
 105             return ret;
 106         }
 107         if (n == 0) {
 108             krb5_set_error_message(context, KRB5_SENDAUTH_BADAUTHVERS,
 109                                    N_("Failed to receive sendauth data", ""));
 110             return KRB5_SENDAUTH_BADAUTHVERS;
 111         }
 112         len = ntohl(len);
 113         if (len != sizeof(her_version)
 114             || krb5_net_read (context, p_fd, her_version, len) != len
 115             || strncmp (version, her_version, len)) {
 116             repl = 1;
 117             krb5_net_write (context, p_fd, &repl, 1);
 118             krb5_clear_error_message (context);
 119             return KRB5_SENDAUTH_BADAUTHVERS;
 120         }
 121     }
 122
 123     n = krb5_net_read (context, p_fd, &len, 4);
 124     if (n < 0) {
 125         ret = errno;
 126         krb5_set_error_message(context, ret, "read: %s", strerror(ret));
 127         return ret;
 128     }
 129     if (n == 0) {
 130         krb5_clear_error_message (context);
 131         return KRB5_SENDAUTH_BADAPPLVERS;
 132     }
 133     len = ntohl(len);
 134     her_appl_version = malloc (len);
 135     if (her_appl_version == NULL) {
 136         repl = 2;
 137         krb5_net_write (context, p_fd, &repl, 1);
 138         krb5_set_error_message(context, ENOMEM,
 139                                N_("malloc: out of memory", ""));
 140         return ENOMEM;
 141     }
 142     if (krb5_net_read (context, p_fd, her_appl_version, len) != len
 143         || !(*match_appl_version)(match_data, her_appl_version)) {
 144         repl = 2;
 145         krb5_net_write (context, p_fd, &repl, 1);
 146         krb5_set_error_message(context, KRB5_SENDAUTH_BADAPPLVERS,
 147                                N_("wrong sendauth version (%s)", ""),
 148                                her_appl_version);
 149         free (her_appl_version);
 150         return KRB5_SENDAUTH_BADAPPLVERS;
 151     }
 152     free (her_appl_version);
 153
 154     repl = 0;
 155     if (krb5_net_write (context, p_fd, &repl, 1) != 1) {
 156         ret = errno;
 157         krb5_set_error_message(context, ret, "write: %s", strerror(ret));
 158         return ret;
 159     }
 160
 161     krb5_data_zero (&data);
 162     ret = krb5_read_message (context, p_fd, &data);
 163     if (ret)
 164         return ret;
 165
 166     ret = krb5_rd_req (context,
 167                        auth_context,
 168                        &data,
 169                        server,
 170                        keytab,
 171                        &ap_options,
 172                        ticket);
 173     krb5_data_free (&data);
 174     if (ret) {
 175         krb5_data error_data;
 176         krb5_error_code ret2;
 177
 178         ret2 = krb5_mk_error (context,
 179                               ret,
 180                               NULL,
 181                               NULL,
 182                               NULL,
 183                               server,
 184                               NULL,
 185                               NULL,
 186                               &error_data);
 187         if (ret2 == 0) {
 188             krb5_write_message (context, p_fd, &error_data);
 189             krb5_data_free (&error_data);
 190         }
 191         return ret;
 192     }
 193
 194     len = 0;
 195     if (krb5_net_write (context, p_fd, &len, 4) != 4) {
 196         ret = errno;
 197         krb5_set_error_message(context, ret, "write: %s", strerror(ret));
 198         krb5_free_ticket(context, *ticket);
 199         *ticket = NULL;
 200         return ret;
 201     }
 202
 203     if (ap_options & AP_OPTS_MUTUAL_REQUIRED) {
 204         ret = krb5_mk_rep (context, *auth_context, &data);
 205         if (ret) {
 206             krb5_free_ticket(context, *ticket);
 207             *ticket = NULL;
 208             return ret;
 209         }
 210
 211         ret = krb5_write_message (context, p_fd, &data);
 212         if (ret) {
 213             krb5_free_ticket(context, *ticket);
 214             *ticket = NULL;
 215             return ret;
 216         }
 217         krb5_data_free (&data);
 218     }
 219     return 0;
 220 }