freebsd-skq/lib/libmd/mdXhl.c
Jonathan T. Looney 492e9ee5a9 Improvements to the MDXFileChunk() template function:
- Remove unneeded fstat()/lseek() calls.
- Return NULL and set errno to EINVAL on negative length.
- Fix small style problems and expand variable names.

After this change, it is possible to use this code for some irregular
files. For example, 'md5 /dev/md0' should now succeed.

Differential Revision:	https://reviews.freebsd.org/D4748
Suggested by:	bde
Reviewed by:	bde, allanjude, delphij
2016-01-14 21:08:23 +00:00

121 lines
2.5 KiB
C

/* mdXhl.c
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@FreeBSD.org> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include "mdX.h"
char *
MDXEnd(MDX_CTX *ctx, char *buf)
{
int i;
unsigned char digest[LENGTH];
static const char hex[]="0123456789abcdef";
if (!buf)
buf = malloc(2*LENGTH + 1);
if (!buf)
return 0;
MDXFinal(digest, ctx);
for (i = 0; i < LENGTH; i++) {
buf[i+i] = hex[digest[i] >> 4];
buf[i+i+1] = hex[digest[i] & 0x0f];
}
buf[i+i] = '\0';
return buf;
}
char *
MDXFile(const char *filename, char *buf)
{
return (MDXFileChunk(filename, buf, 0, 0));
}
char *
MDXFileChunk(const char *filename, char *buf, off_t ofs, off_t len)
{
unsigned char buffer[16*1024];
MDX_CTX ctx;
struct stat stbuf;
int fd, readrv, e;
off_t remain;
if (len < 0) {
errno = EINVAL;
return NULL;
}
MDXInit(&ctx);
fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
if (ofs != 0) {
errno = 0;
if (lseek(fd, ofs, SEEK_SET) != ofs ||
(ofs == -1 && errno != 0)) {
readrv = -1;
goto error;
}
}
remain = len;
readrv = 0;
while (len == 0 || remain > 0) {
if (len == 0 || remain > sizeof(buffer))
readrv = read(fd, buffer, sizeof(buffer));
else
readrv = read(fd, buffer, remain);
if (readrv <= 0)
break;
MDXUpdate(&ctx, buffer, readrv);
remain -= readrv;
}
error:
e = errno;
close(fd);
errno = e;
if (readrv < 0)
return NULL;
return (MDXEnd(&ctx, buf));
}
char *
MDXData (const void *data, unsigned int len, char *buf)
{
MDX_CTX ctx;
MDXInit(&ctx);
MDXUpdate(&ctx,data,len);
return (MDXEnd(&ctx, buf));
}
#ifdef WEAK_REFS
/* When building libmd, provide weak references. Note: this is not
activated in the context of compiling these sources for internal
use in libcrypt.
*/
#undef MDXEnd
__weak_reference(_libmd_MDXEnd, MDXEnd);
#undef MDXFile
__weak_reference(_libmd_MDXFile, MDXFile);
#undef MDXFileChunk
__weak_reference(_libmd_MDXFileChunk, MDXFileChunk);
#undef MDXData
__weak_reference(_libmd_MDXData, MDXData);
#endif