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     size_t n = numBytes;
  40     return writeFileSizet(fileName, bytes, n);
  41 }
  42
  43 int writeFileSizet(
  44         const char                      *fileName,
  45         const unsigned char     *bytes,
  46         size_t                  numBytes)
  47 {
  48         int             rtn;
  49         int     fd;
  50
  51         fd = open(fileName, O_RDWR | O_CREAT | O_TRUNC, 0600);
  52         if(fd < 0) {
  53                 return errno;
  54         }
  55         rtn = (int)lseek(fd, 0, SEEK_SET);
  56         if(rtn < 0) {
  57                 return errno;
  58         }
  59         rtn = (int)write(fd, bytes, (size_t)numBytes);
  60         if(rtn != (int)numBytes) {
  61                 if(rtn >= 0) {
  62                         printf("writeFile: short write\n");
  63                 }
  64                 rtn = EIO;
  65         }
  66         else {
  67                 rtn = 0;
  68         }
  69         close(fd);
  70         return rtn;
  71 }
  72
  73 /*
  74  * Read entire file.
  75  */
  76 int readFile(
  77         const char              *fileName,
  78         unsigned char   **bytes,                // mallocd and returned
  79         unsigned                *numBytes)              // returned
  80 {
  81         int rtn;
  82         int fd;
  83         unsigned char *buf;
  84         struct stat     sb;
  85         unsigned size;
  86
  87         *numBytes = 0;
  88         *bytes = NULL;
  89         fd = open(fileName, O_RDONLY, 0);
  90         if(fd < 0) {
  91                 return errno;
  92         }
  93         rtn = fstat(fd, &sb);
  94         if(rtn) {
  95                 goto errOut;
  96         }
  97         size = (unsigned)sb.st_size;
  98         buf = malloc(size);
  99         if(buf == NULL) {
 100                 rtn = ENOMEM;
 101                 goto errOut;
 102         }
 103         rtn = (int)lseek(fd, 0, SEEK_SET);
 104         if(rtn < 0) {
 105                 free(buf);
 106                 goto errOut;
 107         }
 108         rtn = (int)read(fd, buf, (size_t)size);
 109         if(rtn != (int)size) {
 110                 if(rtn >= 0) {
 111                         printf("readFile: short read\n");
 112                 }
 113                 free(buf);
 114                 rtn = EIO;
 115         }
 116         else {
 117                 rtn = 0;
 118                 *bytes = buf;
 119                 *numBytes = size;
 120         }
 121 errOut:
 122         close(fd);
 123         return rtn;
 124 }