source4/auth/kerberos/gssapi_parse.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    simple GSSAPI wrappers
   5
   6    Copyright (C) Andrew Tridgell 2001
   7    Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2002
   8    Copyright (C) Luke Howard     2003
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "../lib/util/asn1.h"
  26 #include "auth/gensec/gensec.h"
  27 #include "system/kerberos.h"
  28 #include "auth/kerberos/kerberos.h"
  29
  30 /*
  31   generate a krb5 GSS-API wrapper packet given a ticket
  32 */
  33 DATA_BLOB gensec_gssapi_gen_krb5_wrap(TALLOC_CTX *mem_ctx, const DATA_BLOB *ticket, const uint8_t tok_id[2])
  34 {
  35         struct asn1_data *data;
  36         DATA_BLOB ret;
  37
  38         data = asn1_init(mem_ctx);
  39         if (!data || !ticket->data) {
  40                 return data_blob(NULL,0);
  41         }
  42
  43         asn1_push_tag(data, ASN1_APPLICATION(0));
  44         asn1_write_OID(data, GENSEC_OID_KERBEROS5);
  45
  46         asn1_write(data, tok_id, 2);
  47         asn1_write(data, ticket->data, ticket->length);
  48         asn1_pop_tag(data);
  49
  50         if (data->has_error) {
  51                 DEBUG(1,("Failed to build krb5 wrapper at offset %d\n", (int)data->ofs));
  52                 asn1_free(data);
  53                 return data_blob(NULL,0);
  54         }
  55
  56         ret = data_blob_talloc(mem_ctx, data->data, data->length);
  57         asn1_free(data);
  58
  59         return ret;
  60 }
  61
  62 /*
  63   parse a krb5 GSS-API wrapper packet giving a ticket
  64 */
  65 bool gensec_gssapi_parse_krb5_wrap(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob, DATA_BLOB *ticket, uint8_t tok_id[2])
  66 {
  67         bool ret;
  68         struct asn1_data *data = asn1_init(mem_ctx);
  69         int data_remaining;
  70
  71         if (!data) {
  72                 return false;
  73         }
  74
  75         asn1_load(data, *blob);
  76         asn1_start_tag(data, ASN1_APPLICATION(0));
  77         asn1_check_OID(data, GENSEC_OID_KERBEROS5);
  78
  79         data_remaining = asn1_tag_remaining(data);
  80
  81         if (data_remaining < 3) {
  82                 data->has_error = true;
  83         } else {
  84                 asn1_read(data, tok_id, 2);
  85                 data_remaining -= 2;
  86                 *ticket = data_blob_talloc(mem_ctx, NULL, data_remaining);
  87                 asn1_read(data, ticket->data, ticket->length);
  88         }
  89
  90         asn1_end_tag(data);
  91
  92         ret = !data->has_error;
  93
  94         asn1_free(data);
  95
  96         return ret;
  97 }
  98
  99
 100 /*
 101   check a GSS-API wrapper packet givin an expected OID
 102 */
 103 bool gensec_gssapi_check_oid(const DATA_BLOB *blob, const char *oid)
 104 {
 105         bool ret;
 106         struct asn1_data *data = asn1_init(NULL);
 107
 108         if (!data) return false;
 109
 110         asn1_load(data, *blob);
 111         asn1_start_tag(data, ASN1_APPLICATION(0));
 112         asn1_check_OID(data, oid);
 113
 114         ret = !data->has_error;
 115
 116         asn1_free(data);
 117
 118         return ret;
 119 }
 120
 121