crypto/dist/heimdal/lib/krb5/store_mem.c

   1 /*
   2  * Copyright (c) 1997 - 2000, 2002 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 #include "store-int.h"
  36
  37 __RCSID("$Heimdal: store_mem.c 20307 2007-04-11 11:16:28Z lha $"
  38         "$NetBSD$");
  39
  40 typedef struct mem_storage{
  41     unsigned char *base;
  42     size_t size;
  43     unsigned char *ptr;
  44 }mem_storage;
  45
  46 static ssize_t
  47 mem_fetch(krb5_storage *sp, void *data, size_t size)
  48 {
  49     mem_storage *s = (mem_storage*)sp->data;
  50     if(size > s->base + s->size - s->ptr)
  51         size = s->base + s->size - s->ptr;
  52     memmove(data, s->ptr, size);
  53     sp->seek(sp, size, SEEK_CUR);
  54     return size;
  55 }
  56
  57 static ssize_t
  58 mem_store(krb5_storage *sp, const void *data, size_t size)
  59 {
  60     mem_storage *s = (mem_storage*)sp->data;
  61     if(size > s->base + s->size - s->ptr)
  62         size = s->base + s->size - s->ptr;
  63     memmove(s->ptr, data, size);
  64     sp->seek(sp, size, SEEK_CUR);
  65     return size;
  66 }
  67
  68 static ssize_t
  69 mem_no_store(krb5_storage *sp, const void *data, size_t size)
  70 {
  71     return -1;
  72 }
  73
  74 static off_t
  75 mem_seek(krb5_storage *sp, off_t offset, int whence)
  76 {
  77     mem_storage *s = (mem_storage*)sp->data;
  78     switch(whence){
  79     case SEEK_SET:
  80         if(offset > s->size)
  81             offset = s->size;
  82         if(offset < 0)
  83             offset = 0;
  84         s->ptr = s->base + offset;
  85         break;
  86     case SEEK_CUR:
  87         return sp->seek(sp, s->ptr - s->base + offset, SEEK_SET);
  88     case SEEK_END:
  89         return sp->seek(sp, s->size + offset, SEEK_SET);
  90     default:
  91         errno = EINVAL;
  92         return -1;
  93     }
  94     return s->ptr - s->base;
  95 }
  96
  97 krb5_storage * KRB5_LIB_FUNCTION
  98 krb5_storage_from_mem(void *buf, size_t len)
  99 {
 100     krb5_storage *sp = malloc(sizeof(krb5_storage));
 101     mem_storage *s;
 102     if(sp == NULL)
 103         return NULL;
 104     s = malloc(sizeof(*s));
 105     if(s == NULL) {
 106         free(sp);
 107         return NULL;
 108     }
 109     sp->data = s;
 110     sp->flags = 0;
 111     sp->eof_code = HEIM_ERR_EOF;
 112     s->base = buf;
 113     s->size = len;
 114     s->ptr = buf;
 115     sp->fetch = mem_fetch;
 116     sp->store = mem_store;
 117     sp->seek = mem_seek;
 118     sp->free = NULL;
 119     return sp;
 120 }
 121
 122 krb5_storage * KRB5_LIB_FUNCTION
 123 krb5_storage_from_data(krb5_data *data)
 124 {
 125     return krb5_storage_from_mem(data->data, data->length);
 126 }
 127
 128 krb5_storage * KRB5_LIB_FUNCTION
 129 krb5_storage_from_readonly_mem(const void *buf, size_t len)
 130 {
 131     krb5_storage *sp = malloc(sizeof(krb5_storage));
 132     mem_storage *s;
 133     if(sp == NULL)
 134         return NULL;
 135     s = malloc(sizeof(*s));
 136     if(s == NULL) {
 137         free(sp);
 138         return NULL;
 139     }
 140     sp->data = s;
 141     sp->flags = 0;
 142     sp->eof_code = HEIM_ERR_EOF;
 143     s->base = rk_UNCONST(buf);
 144     s->size = len;
 145     s->ptr = rk_UNCONST(buf);
 146     sp->fetch = mem_fetch;
 147     sp->store = mem_no_store;
 148     sp->seek = mem_seek;
 149     sp->free = NULL;
 150     return sp;
 151 }