src/lib/krb5/krb/ser_key.c

   1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
   2 /* lib/krb5/krb/ser_key.c - Serialize krb5_keyblock structure */
   3 /*
   4  * Copyright 1995, 2008 by the Massachusetts Institute of Technology.
   5  * All Rights Reserved.
   6  *
   7  * Export of this software from the United States of America may
   8  *   require a specific license from the United States Government.
   9  *   It is the responsibility of any person or organization contemplating
  10  *   export to obtain such a license before exporting.
  11  *
  12  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
  13  * distribute this software and its documentation for any purpose and
  14  * without fee is hereby granted, provided that the above copyright
  15  * notice appear in all copies and that both that copyright notice and
  16  * this permission notice appear in supporting documentation, and that
  17  * the name of M.I.T. not be used in advertising or publicity pertaining
  18  * to distribution of the software without specific, written prior
  19  * permission.  Furthermore if you modify this software you must label
  20  * your software as modified software and not distribute it in such a
  21  * fashion that it might be confused with the original M.I.T. software.
  22  * M.I.T. makes no representations about the suitability of
  23  * this software for any purpose.  It is provided "as is" without express
  24  * or implied warranty.
  25  */
  26
  27 #include "k5-int.h"
  28 #include "int-proto.h"
  29
  30 krb5_error_code
  31 k5_size_keyblock(krb5_keyblock *keyblock, size_t *sizep)
  32 {
  33     krb5_error_code     kret;
  34
  35     /*
  36      * krb5_keyblock requires:
  37      *  krb5_int32                      for KV5M_KEYBLOCK
  38      *  krb5_int32                      for enctype
  39      *  krb5_int32                      for length
  40      *  keyblock->length                for contents
  41      *  krb5_int32                      for KV5M_KEYBLOCK
  42      */
  43     kret = EINVAL;
  44     if (keyblock != NULL) {
  45         *sizep += 4 * sizeof(krb5_int32) + keyblock->length;
  46         kret = 0;
  47     }
  48     return(kret);
  49 }
  50
  51 krb5_error_code
  52 k5_externalize_keyblock(krb5_keyblock *keyblock,
  53                         krb5_octet **buffer, size_t *lenremain)
  54 {
  55     krb5_error_code     kret;
  56     size_t              required;
  57     krb5_octet          *bp;
  58     size_t              remain;
  59
  60     required = 0;
  61     bp = *buffer;
  62     remain = *lenremain;
  63     kret = EINVAL;
  64     if (keyblock != NULL) {
  65         kret = ENOMEM;
  66         if (!k5_size_keyblock(keyblock, &required) && required <= remain) {
  67             /* Our identifier */
  68             (void) krb5_ser_pack_int32(KV5M_KEYBLOCK, &bp, &remain);
  69
  70             /* Our enctype */
  71             (void) krb5_ser_pack_int32((krb5_int32) keyblock->enctype,
  72                                        &bp, &remain);
  73
  74             /* Our length */
  75             (void) krb5_ser_pack_int32((krb5_int32) keyblock->length,
  76                                        &bp, &remain);
  77
  78             /* Our contents */
  79             (void) krb5_ser_pack_bytes(keyblock->contents,
  80                                        (size_t) keyblock->length,
  81                                        &bp, &remain);
  82
  83             /* Finally, our trailer */
  84             (void) krb5_ser_pack_int32(KV5M_KEYBLOCK, &bp, &remain);
  85
  86             kret = 0;
  87             *buffer = bp;
  88             *lenremain = remain;
  89         }
  90     }
  91     return(kret);
  92 }
  93
  94 krb5_error_code
  95 k5_internalize_keyblock(krb5_keyblock **argp,
  96                         krb5_octet **buffer, size_t *lenremain)
  97 {
  98     krb5_error_code     kret;
  99     krb5_keyblock       *keyblock;
 100     krb5_int32          ibuf;
 101     krb5_octet          *bp;
 102     size_t              remain;
 103
 104     bp = *buffer;
 105     remain = *lenremain;
 106     kret = EINVAL;
 107     /* Read our magic number */
 108     if (krb5_ser_unpack_int32(&ibuf, &bp, &remain))
 109         ibuf = 0;
 110     if (ibuf == KV5M_KEYBLOCK) {
 111         kret = ENOMEM;
 112
 113         /* Get a keyblock */
 114         if ((remain >= (3*sizeof(krb5_int32))) &&
 115             (keyblock = (krb5_keyblock *) calloc(1, sizeof(krb5_keyblock)))) {
 116             /* Get the enctype */
 117             (void) krb5_ser_unpack_int32(&ibuf, &bp, &remain);
 118             keyblock->enctype = (krb5_enctype) ibuf;
 119
 120             /* Get the length */
 121             (void) krb5_ser_unpack_int32(&ibuf, &bp, &remain);
 122             keyblock->length = (int) ibuf;
 123
 124             /* Get the string */
 125             if ((keyblock->contents = (krb5_octet *) malloc((size_t) (ibuf)))&&
 126                 !(kret = krb5_ser_unpack_bytes(keyblock->contents,
 127                                                (size_t) ibuf,
 128                                                &bp, &remain))) {
 129                 kret = krb5_ser_unpack_int32(&ibuf, &bp, &remain);
 130                 if (!kret && (ibuf == KV5M_KEYBLOCK)) {
 131                     kret = 0;
 132                     *buffer = bp;
 133                     *lenremain = remain;
 134                     keyblock->magic = KV5M_KEYBLOCK;
 135                     *argp = keyblock;
 136                 }
 137                 else
 138                     kret = EINVAL;
 139             }
 140             if (kret) {
 141                 if (keyblock->contents)
 142                     free(keyblock->contents);
 143                 free(keyblock);
 144             }
 145         }
 146     }
 147     return(kret);
 148 }