libsecurity_keychain/libDER/libDERUtils/fileIo.c

   1 /*
   2  * Copyright (c) 2005-2007,2010 Apple Inc. All Rights Reserved.
   3  */
   4
   5 #include <unistd.h>
   6 #include <fcntl.h>
   7 #include <errno.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <sys/types.h>
  11 #include <sys/stat.h>
  12 #include "fileIo.h"
  13
  14 int writeFile(
  15         const char                      *fileName,
  16         const unsigned char     *bytes,
  17         unsigned                        numBytes)
  18 {
  19         int             rtn;
  20         int     fd;
  21
  22         fd = open(fileName, O_RDWR | O_CREAT | O_TRUNC, 0600);
  23         if(fd <= 0) {
  24                 return errno;
  25         }
  26         rtn = write(fd, bytes, (size_t)numBytes);
  27         if(rtn != (int)numBytes) {
  28                 if(rtn >= 0) {
  29                         fprintf(stderr, "writeFile: short write\n");
  30                 }
  31                 rtn = EIO;
  32         }
  33         else {
  34                 rtn = 0;
  35         }
  36         close(fd);
  37         return rtn;
  38 }
  39
  40 /*
  41  * Read entire file.
  42  */
  43 int readFile(
  44         const char              *fileName,
  45         unsigned char   **bytes,                // mallocd and returned
  46         unsigned                *numBytes)              // returned
  47 {
  48         int rtn;
  49         int fd;
  50         char *buf;
  51         struct stat     sb;
  52         size_t size;
  53
  54         *numBytes = 0;
  55         *bytes = NULL;
  56         fd = open(fileName, O_RDONLY, 0);
  57         if(fd <= 0) {
  58                 return errno;
  59         }
  60         rtn = fstat(fd, &sb);
  61         if(rtn) {
  62                 goto errOut;
  63         }
  64         size = (size_t) sb.st_size;
  65         buf = (char *)malloc(size);
  66         if(buf == NULL) {
  67                 rtn = ENOMEM;
  68                 goto errOut;
  69         }
  70         rtn = read(fd, buf, (size_t)size);
  71         if(rtn != (int)size) {
  72                 if(rtn >= 0) {
  73                         fprintf(stderr, "readFile: short read\n");
  74                 }
  75                 rtn = EIO;
  76         }
  77         else {
  78                 rtn = 0;
  79                 *bytes = (unsigned char *)buf;
  80                 *numBytes = size;
  81         }
  82 errOut:
  83         close(fd);
  84         return rtn;
  85 }