OSX/libsecurity_cdsa_utils/lib/cuFileIo.c

   1 /*
   2  * Copyright (c) 2001-2003,2011-2012,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please
   7  * obtain a copy of the License at http://www.apple.com/publicsource and
   8  * read it before using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  12  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  13  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  14  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  15  * Please see the License for the specific language governing rights and
  16  * limitations under the License.
  17  */
  18
  19 /*
  20         File:            cuFileIo.c
  21
  22         Description: simple file read/write utilities
  23 */
  24
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <sys/types.h>
  31 #include <sys/stat.h>
  32 #include "cuFileIo.h"
  33
  34 int writeFile(
  35         const char                      *fileName,
  36         const unsigned char     *bytes,
  37         unsigned                        numBytes)
  38 {
  39         int             rtn;
  40         int     fd;
  41
  42         fd = open(fileName, O_RDWR | O_CREAT | O_TRUNC, 0600);
  43         if(fd < 0) {
  44                 return errno;
  45         }
  46         rtn = (int)lseek(fd, 0, SEEK_SET);
  47         if(rtn < 0) {
  48                 return errno;
  49         }
  50         rtn = (int)write(fd, bytes, (size_t)numBytes);
  51         if(rtn != (int)numBytes) {
  52                 if(rtn >= 0) {
  53                         printf("writeFile: short write\n");
  54                 }
  55                 rtn = EIO;
  56         }
  57         else {
  58                 rtn = 0;
  59         }
  60         close(fd);
  61         return rtn;
  62 }
  63
  64 /*
  65  * Read entire file.
  66  */
  67 int readFile(
  68         const char              *fileName,
  69         unsigned char   **bytes,                // mallocd and returned
  70         unsigned                *numBytes)              // returned
  71 {
  72         int rtn;
  73         int fd;
  74         unsigned char *buf;
  75         struct stat     sb;
  76         unsigned size;
  77
  78         *numBytes = 0;
  79         *bytes = NULL;
  80         fd = open(fileName, O_RDONLY, 0);
  81         if(fd < 0) {
  82                 return errno;
  83         }
  84         rtn = fstat(fd, &sb);
  85         if(rtn) {
  86                 goto errOut;
  87         }
  88         size = (unsigned)sb.st_size;
  89         buf = malloc(size);
  90         if(buf == NULL) {
  91                 rtn = ENOMEM;
  92                 goto errOut;
  93         }
  94         rtn = (int)lseek(fd, 0, SEEK_SET);
  95         if(rtn < 0) {
  96                 goto errOut;
  97         }
  98         rtn = (int)read(fd, buf, (size_t)size);
  99         if(rtn != (int)size) {
 100                 if(rtn >= 0) {
 101                         printf("readFile: short read\n");
 102                 }
 103                 rtn = EIO;
 104         }
 105         else {
 106                 rtn = 0;
 107                 *bytes = buf;
 108                 *numBytes = size;
 109         }
 110 errOut:
 111         close(fd);
 112         return rtn;
 113 }