mirror of
https://github.com/git/git.git
synced 2024-11-27 12:03:55 +08:00
d4e85a1afe
Previously, get_sha1_hex() would read one character past the end of a null-terminated string whose strlen was an even number less than 40. Although the function correctly returned -1 in these cases, the extra memory access might have been to uninitialized (or even, conceivably, unallocated) memory. Add a check to avoid reading past the end of a string. This problem was discovered by Thomas Rast <trast@student.ethz.ch> using valgrind. Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
76 lines
2.3 KiB
C
76 lines
2.3 KiB
C
#include "cache.h"
|
|
|
|
const signed char hexval_table[256] = {
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
|
|
0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
|
|
8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
|
|
-1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
|
|
-1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
|
|
-1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
|
|
};
|
|
|
|
int get_sha1_hex(const char *hex, unsigned char *sha1)
|
|
{
|
|
int i;
|
|
for (i = 0; i < 20; i++) {
|
|
unsigned int val;
|
|
/*
|
|
* hex[1]=='\0' is caught when val is checked below,
|
|
* but if hex[0] is NUL we have to avoid reading
|
|
* past the end of the string:
|
|
*/
|
|
if (!hex[0])
|
|
return -1;
|
|
val = (hexval(hex[0]) << 4) | hexval(hex[1]);
|
|
if (val & ~0xff)
|
|
return -1;
|
|
*sha1++ = val;
|
|
hex += 2;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
char *sha1_to_hex(const unsigned char *sha1)
|
|
{
|
|
static int bufno;
|
|
static char hexbuffer[4][50];
|
|
static const char hex[] = "0123456789abcdef";
|
|
char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
|
|
int i;
|
|
|
|
for (i = 0; i < 20; i++) {
|
|
unsigned int val = *sha1++;
|
|
*buf++ = hex[val >> 4];
|
|
*buf++ = hex[val & 0xf];
|
|
}
|
|
*buf = '\0';
|
|
|
|
return buffer;
|
|
}
|