release/src/router/nfs-utils/utils/gssd/context_lucid.c

   1 /*
   2  * COPYRIGHT (c) 2006
   3  * The Regents of the University of Michigan
   4  * ALL RIGHTS RESERVED
   5  *
   6  * Permission is granted to use, copy, create derivative works
   7  * and redistribute this software and such derivative works
   8  * for any purpose, so long as the name of The University of
   9  * Michigan is not used in any advertising or publicity
  10  * pertaining to the use of distribution of this software
  11  * without specific, written prior authorization.  If the
  12  * above copyright notice or any other identification of the
  13  * University of Michigan is included in any copy of any
  14  * portion of this software, then the disclaimer below must
  15  * also be included.
  16  *
  17  * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
  18  * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
  19  * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
  20  * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
  21  * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
  22  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
  23  * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
  24  * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
  25  * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
  26  * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
  27  * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGES.
  29  */
  30
  31 #ifdef HAVE_CONFIG_H
  32 #include <config.h>
  33 #endif  /* HAVE_CONFIG_H */
  34
  35 #ifdef HAVE_LUCID_CONTEXT_SUPPORT
  36
  37 /*
  38  * Newer versions of MIT and Heimdal have lucid context support.
  39  * We can use common code if it is supported.
  40  */
  41
  42 #include <stdio.h>
  43 #include <syslog.h>
  44 #include <string.h>
  45
  46 #include <gssapi/gssapi_krb5.h>
  47
  48 #include "gss_util.h"
  49 #include "gss_oids.h"
  50 #include "err_util.h"
  51 #include "context.h"
  52
  53 #ifndef OM_uint64
  54 typedef uint64_t OM_uint64;
  55 #endif
  56
  57 static int
  58 write_lucid_keyblock(char **p, char *end, gss_krb5_lucid_key_t *key)
  59 {
  60         gss_buffer_desc tmp;
  61
  62         if (WRITE_BYTES(p, end, key->type)) return -1;
  63         tmp.length = key->length;
  64         tmp.value = key->data;
  65         if (write_buffer(p, end, &tmp)) return -1;
  66         return 0;
  67 }
  68
  69 static int
  70 prepare_krb5_rfc1964_buffer(gss_krb5_lucid_context_v1_t *lctx,
  71         gss_buffer_desc *buf, int32_t *endtime)
  72 {
  73         char *p, *end;
  74         static int constant_zero = 0;
  75         unsigned char fakeseed[16];
  76         uint32_t word_send_seq;
  77         gss_krb5_lucid_key_t enc_key;
  78         int i;
  79         char *skd, *dkd;
  80         gss_buffer_desc fakeoid;
  81
  82         /*
  83          * The new Kerberos interface to get the gss context
  84          * does not include the seed or seed_init fields
  85          * because we never really use them.  But for now,
  86          * send down a fake buffer so we can use the same
  87          * interface to the kernel.
  88          */
  89         memset(&enc_key, 0, sizeof(enc_key));
  90         memset(&fakeoid, 0, sizeof(fakeoid));
  91
  92         if (!(buf->value = calloc(1, MAX_CTX_LEN)))
  93                 goto out_err;
  94         p = buf->value;
  95         end = buf->value + MAX_CTX_LEN;
  96
  97         if (WRITE_BYTES(&p, end, lctx->initiate)) goto out_err;
  98
  99         /* seed_init and seed not used by kernel anyway */
 100         if (WRITE_BYTES(&p, end, constant_zero)) goto out_err;
 101         if (write_bytes(&p, end, &fakeseed, 16)) goto out_err;
 102
 103         if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.sign_alg)) goto out_err;
 104         if (WRITE_BYTES(&p, end, lctx->rfc1964_kd.seal_alg)) goto out_err;
 105         if (WRITE_BYTES(&p, end, lctx->endtime)) goto out_err;
 106         if (endtime)
 107                 *endtime = lctx->endtime;
 108         word_send_seq = lctx->send_seq; /* XXX send_seq is 64-bit */
 109         if (WRITE_BYTES(&p, end, word_send_seq)) goto out_err;
 110         if (write_oid(&p, end, &krb5oid)) goto out_err;
 111
 112 #ifdef HAVE_HEIMDAL
 113         /*
 114          * The kernel gss code expects des-cbc-raw for all flavors of des.
 115          * The keytype from MIT has this type, but Heimdal does not.
 116          * Force the Heimdal keytype to 4 (des-cbc-raw).
 117          * Note that the rfc1964 version only supports DES enctypes.
 118          */
 119         if (lctx->rfc1964_kd.ctx_key.type != 4) {
 120                 printerr(1, "prepare_krb5_rfc1964_buffer: "
 121                             "overriding heimdal keytype (%d => %d)\n",
 122                             lctx->rfc1964_kd.ctx_key.type, 4);
 123                 lctx->rfc1964_kd.ctx_key.type = 4;
 124         }
 125 #endif
 126         printerr(2, "prepare_krb5_rfc1964_buffer: serializing keys with "
 127                  "enctype %d and length %d\n",
 128                  lctx->rfc1964_kd.ctx_key.type,
 129                  lctx->rfc1964_kd.ctx_key.length);
 130
 131         /* derive the encryption key and copy it into buffer */
 132         enc_key.type = lctx->rfc1964_kd.ctx_key.type;
 133         enc_key.length = lctx->rfc1964_kd.ctx_key.length;
 134         if ((enc_key.data = calloc(1, enc_key.length)) == NULL)
 135                 goto out_err;
 136         skd = (char *) lctx->rfc1964_kd.ctx_key.data;
 137         dkd = (char *) enc_key.data;
 138         for (i = 0; i < enc_key.length; i++)
 139                 dkd[i] = skd[i] ^ 0xf0;
 140         if (write_lucid_keyblock(&p, end, &enc_key)) {
 141                 free(enc_key.data);
 142                 goto out_err;
 143         }
 144         free(enc_key.data);
 145
 146         if (write_lucid_keyblock(&p, end, &lctx->rfc1964_kd.ctx_key))
 147                 goto out_err;
 148
 149         buf->length = p - (char *)buf->value;
 150         return 0;
 151 out_err:
 152         printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
 153         if (buf->value) free(buf->value);
 154         buf->length = 0;
 155         if (enc_key.data) free(enc_key.data);
 156         return -1;
 157 }
 158
 159 static int
 160 prepare_krb5_rfc_cfx_buffer(gss_krb5_lucid_context_v1_t *lctx,
 161         gss_buffer_desc *buf, int32_t *endtime)
 162 {
 163         printerr(0, "ERROR: prepare_krb5_rfc_cfx_buffer: not implemented\n");
 164         return -1;
 165 }
 166
 167
 168 int
 169 serialize_krb5_ctx(gss_ctx_id_t ctx, gss_buffer_desc *buf, int32_t *endtime)
 170 {
 171         OM_uint32 maj_stat, min_stat;
 172         void *return_ctx = 0;
 173         OM_uint32 vers;
 174         gss_krb5_lucid_context_v1_t *lctx = 0;
 175         int retcode = 0;
 176
 177         printerr(2, "DEBUG: serialize_krb5_ctx: lucid version!\n");
 178         maj_stat = gss_export_lucid_sec_context(&min_stat, &ctx,
 179                                                 1, &return_ctx);
 180         if (maj_stat != GSS_S_COMPLETE) {
 181                 pgsserr("gss_export_lucid_sec_context",
 182                         maj_stat, min_stat, &krb5oid);
 183                 goto out_err;
 184         }
 185
 186         /* Check the version returned, we only support v1 right now */
 187         vers = ((gss_krb5_lucid_context_version_t *)return_ctx)->version;
 188         switch (vers) {
 189         case 1:
 190                 lctx = (gss_krb5_lucid_context_v1_t *) return_ctx;
 191                 break;
 192         default:
 193                 printerr(0, "ERROR: unsupported lucid sec context version %d\n",
 194                         vers);
 195                 goto out_err;
 196                 break;
 197         }
 198
 199         /* Now lctx points to a lucid context that we can send down to kernel */
 200         if (lctx->protocol == 0)
 201                 retcode = prepare_krb5_rfc1964_buffer(lctx, buf, endtime);
 202         else
 203                 retcode = prepare_krb5_rfc_cfx_buffer(lctx, buf, endtime);
 204
 205         maj_stat = gss_free_lucid_sec_context(&min_stat, ctx, return_ctx);
 206         if (maj_stat != GSS_S_COMPLETE) {
 207                 pgsserr("gss_export_lucid_sec_context",
 208                         maj_stat, min_stat, &krb5oid);
 209                 printerr(0, "WARN: failed to free lucid sec context\n");
 210         }
 211
 212         if (retcode) {
 213                 printerr(1, "serialize_krb5_ctx: prepare_krb5_*_buffer "
 214                          "failed (retcode = %d)\n", retcode);
 215                 goto out_err;
 216         }
 217
 218         return 0;
 219
 220 out_err:
 221         printerr(0, "ERROR: failed serializing krb5 context for kernel\n");
 222         return -1;
 223 }
 224 #endif /* HAVE_LUCID_CONTEXT_SUPPORT */