text_cmds/sort/commoncrypto.c

   1 /* mdXhl.c
   2  * ----------------------------------------------------------------------------
   3  * "THE BEER-WARE LICENSE" (Revision 42):
   4  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
   5  * can do whatever you want with this stuff. If we meet some day, and you think
   6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
   7  * ----------------------------------------------------------------------------
   8  */
   9
  10 #include <sys/cdefs.h>
  11 __FBSDID("$FreeBSD: head/lib/libmd/mdXhl.c 294037 2016-01-14 21:08:23Z jtl $");
  12
  13 #include <sys/types.h>
  14 #include <sys/stat.h>
  15 #include <fcntl.h>
  16 #include <unistd.h>
  17
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21
  22 #include "commoncrypto.h"
  23
  24 #define LENGTH CC_MD5_DIGEST_LENGTH
  25
  26 char *MD5FileChunk(const char *, char *, off_t, off_t);
  27
  28 char *
  29 MD5End(CC_MD5_CTX *ctx, char *buf)
  30 {
  31         int i;
  32         unsigned char digest[LENGTH];
  33         static const char hex[]="0123456789abcdef";
  34
  35         if (!buf)
  36                 buf = malloc(2*LENGTH + 1);
  37         if (!buf)
  38                 return 0;
  39         CC_MD5_Final(digest, ctx);
  40         for (i = 0; i < LENGTH; i++) {
  41                 buf[i+i] = hex[digest[i] >> 4];
  42                 buf[i+i+1] = hex[digest[i] & 0x0f];
  43         }
  44         buf[i+i] = '\0';
  45         return buf;
  46 }
  47
  48 char *
  49 MD5File(const char *filename, char *buf)
  50 {
  51         return (MD5FileChunk(filename, buf, 0, 0));
  52 }
  53
  54 char *
  55 MD5FileChunk(const char *filename, char *buf, off_t ofs, off_t len)
  56 {
  57         unsigned char buffer[16*1024];
  58         CC_MD5_CTX ctx;
  59         int fd, readrv, e;
  60         off_t remain;
  61
  62         if (len < 0) {
  63                 errno = EINVAL;
  64                 return NULL;
  65         }
  66
  67         CC_MD5_Init(&ctx);
  68         fd = open(filename, O_RDONLY);
  69         if (fd < 0)
  70                 return NULL;
  71         if (ofs != 0) {
  72                 errno = 0;
  73                 if (lseek(fd, ofs, SEEK_SET) != ofs ||
  74                     (ofs == -1 && errno != 0)) {
  75                         readrv = -1;
  76                         goto error;
  77                 }
  78         }
  79         remain = len;
  80         readrv = 0;
  81         while (len == 0 || remain > 0) {
  82                 if (len == 0 || remain > (off_t)sizeof(buffer))
  83                         readrv = read(fd, buffer, sizeof(buffer));
  84                 else
  85                         readrv = read(fd, buffer, remain);
  86                 if (readrv <= 0)
  87                         break;
  88                 CC_MD5_Update(&ctx, buffer, readrv);
  89                 remain -= readrv;
  90         }
  91 error:
  92         e = errno;
  93         close(fd);
  94         errno = e;
  95         if (readrv < 0)
  96                 return NULL;
  97         return (MD5End(&ctx, buf));
  98 }