Files
sudo/plugins/sudoers/filedigest.c

142 lines
3.5 KiB
C

/*
* Copyright (c) 2013-2017 Todd C. Miller <Todd.Miller@sudo.ws>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <config.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#if defined(HAVE_STDINT_H)
# include <stdint.h>
#elif defined(HAVE_INTTYPES_H)
# include <inttypes.h>
#endif
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include "sudoers.h"
#ifdef HAVE_SHA224UPDATE
# include <sha2.h>
#else
# include "compat/sha2.h"
#endif
static struct digest_function {
const unsigned int digest_len;
void (*init)(SHA2_CTX *);
#ifdef SHA2_VOID_PTR
void (*update)(SHA2_CTX *, const void *, size_t);
void (*final)(void *, SHA2_CTX *);
#else
void (*update)(SHA2_CTX *, const unsigned char *, size_t);
void (*final)(unsigned char *, SHA2_CTX *);
#endif
} digest_functions[] = {
{
SHA224_DIGEST_LENGTH,
SHA224Init,
SHA224Update,
SHA224Final
}, {
SHA256_DIGEST_LENGTH,
SHA256Init,
SHA256Update,
SHA256Final
}, {
SHA384_DIGEST_LENGTH,
SHA384Init,
SHA384Update,
SHA384Final
}, {
SHA512_DIGEST_LENGTH,
SHA512Init,
SHA512Update,
SHA512Final
}, {
0
}
};
unsigned char *
sudo_filedigest(int fd, const char *file, int digest_type, size_t *digest_len)
{
struct digest_function *func = NULL;
unsigned char *file_digest = NULL;
unsigned char buf[32 * 1024];
size_t nread;
SHA2_CTX ctx;
int i, fd2;
FILE *fp = NULL;
debug_decl(sudo_filedigest, SUDOERS_DEBUG_UTIL)
for (i = 0; digest_functions[i].digest_len != 0; i++) {
if (digest_type == i) {
func = &digest_functions[i];
break;
}
}
if (func == NULL) {
sudo_warnx(U_("unsupported digest type %d for %s"), digest_type, file);
goto bad;
}
if ((fd2 = dup(fd)) == -1) {
sudo_debug_printf(SUDO_DEBUG_INFO, "unable to dup %s: %s",
file, strerror(errno));
goto bad;
}
if ((fp = fdopen(fd2, "r")) == NULL) {
sudo_debug_printf(SUDO_DEBUG_INFO, "unable to fdopen %s: %s",
file, strerror(errno));
close(fd2);
goto bad;
}
if ((file_digest = malloc(func->digest_len)) == NULL) {
sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
goto bad;
}
func->init(&ctx);
while ((nread = fread(buf, 1, sizeof(buf), fp)) != 0) {
func->update(&ctx, buf, nread);
}
if (ferror(fp)) {
sudo_warnx(U_("%s: read error"), file);
goto bad;
}
func->final(file_digest, &ctx);
fclose(fp);
*digest_len = func->digest_len;
debug_return_ptr(file_digest);
bad:
free(file_digest);
if (fp != NULL)
fclose(fp);
debug_return_ptr(NULL);
}