crypto/dist/heimdal/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 __RCSID("$Heimdal: recvauth.c 20306 2007-04-11 11:15:55Z lha $"
  37         "$NetBSD$");
  38
  39 /*
  40  * See `sendauth.c' for the format.
  41  */
  42
  43 static krb5_boolean
  44 match_exact(const void *data, const char *appl_version)
  45 {
  46     return strcmp(data, appl_version) == 0;
  47 }
  48
  49 krb5_error_code KRB5_LIB_FUNCTION
  50 krb5_recvauth(krb5_context context,
  51               krb5_auth_context *auth_context,
  52               krb5_pointer p_fd,
  53               const char *appl_version,
  54               krb5_principal server,
  55               int32_t flags,
  56               krb5_keytab keytab,
  57               krb5_ticket **ticket)
  58 {
  59     return krb5_recvauth_match_version(context, auth_context, p_fd,
  60                                        match_exact, appl_version,
  61                                        server, flags,
  62                                        keytab, ticket);
  63 }
  64
  65 krb5_error_code KRB5_LIB_FUNCTION
  66 krb5_recvauth_match_version(krb5_context context,
  67                             krb5_auth_context *auth_context,
  68                             krb5_pointer p_fd,
  69                             krb5_boolean (*match_appl_version)(const void *,
  70                                                                const char*),
  71                             const void *match_data,
  72                             krb5_principal server,
  73                             int32_t flags,
  74                             krb5_keytab keytab,
  75                             krb5_ticket **ticket)
  76 {
  77     krb5_error_code ret;
  78     const char *version = KRB5_SENDAUTH_VERSION;
  79     char her_version[sizeof(KRB5_SENDAUTH_VERSION)];
  80     char *her_appl_version;
  81     uint32_t len;
  82     u_char repl;
  83     krb5_data data;
  84     krb5_flags ap_options;
  85     ssize_t n;
  86
  87     /*
  88      * If there are no addresses in auth_context, get them from `fd'.
  89      */
  90
  91     if (*auth_context == NULL) {
  92         ret = krb5_auth_con_init (context, auth_context);
  93         if (ret)
  94             return ret;
  95     }
  96
  97     ret = krb5_auth_con_setaddrs_from_fd (context,
  98                                           *auth_context,
  99                                           p_fd);
 100     if (ret)
 101         return ret;
 102
 103     if(!(flags & KRB5_RECVAUTH_IGNORE_VERSION)) {
 104         n = krb5_net_read (context, p_fd, &len, 4);
 105         if (n < 0) {
 106             ret = errno;
 107             krb5_set_error_string (context, "read: %s", strerror(errno));
 108             return ret;
 109         }
 110         if (n == 0) {
 111             krb5_set_error_string (context, "Failed to receive sendauth data");
 112             return KRB5_SENDAUTH_BADAUTHVERS;
 113         }
 114         len = ntohl(len);
 115         if (len != sizeof(her_version)
 116             || krb5_net_read (context, p_fd, her_version, len) != len
 117             || strncmp (version, her_version, len)) {
 118             repl = 1;
 119             krb5_net_write (context, p_fd, &repl, 1);
 120             krb5_clear_error_string (context);
 121             return KRB5_SENDAUTH_BADAUTHVERS;
 122         }
 123     }
 124
 125     n = krb5_net_read (context, p_fd, &len, 4);
 126     if (n < 0) {
 127         ret = errno;
 128         krb5_set_error_string (context, "read: %s", strerror(errno));
 129         return ret;
 130     }
 131     if (n == 0) {
 132         krb5_clear_error_string (context);
 133         return KRB5_SENDAUTH_BADAPPLVERS;
 134     }
 135     len = ntohl(len);
 136     her_appl_version = malloc (len);
 137     if (her_appl_version == NULL) {
 138         repl = 2;
 139         krb5_net_write (context, p_fd, &repl, 1);
 140         krb5_set_error_string (context, "malloc: out of memory");
 141         return ENOMEM;
 142     }
 143     if (krb5_net_read (context, p_fd, her_appl_version, len) != len
 144         || !(*match_appl_version)(match_data, her_appl_version)) {
 145         repl = 2;
 146         krb5_net_write (context, p_fd, &repl, 1);
 147         krb5_set_error_string (context, "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_string (context, "write: %s", strerror(errno));
 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_string (context, "write: %s", strerror(errno));
 198         return ret;
 199     }
 200
 201     if (ap_options & AP_OPTS_MUTUAL_REQUIRED) {
 202         ret = krb5_mk_rep (context, *auth_context, &data);
 203         if (ret)
 204             return ret;
 205
 206         ret = krb5_write_message (context, p_fd, &data);
 207         if (ret)
 208             return ret;
 209         krb5_data_free (&data);
 210     }
 211     return 0;
 212 }