Files
sudo/plugins/sudoers/filedigest_gcrypt.c
Todd C. Miller b9954fb9b9 Add support for using the message digest functions in libgcrypt
instead of sudo's own SHA2 implementation.
2017-02-20 16:44:12 -07:00

114 lines
3.1 KiB
C

/*
* Copyright (c) 2017 Todd C. Miller <Todd.Miller@courtesan.com>
*
* 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 */
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <gcrypt.h>
#include "sudoers.h"
#include "parse.h"
unsigned char *
sudo_filedigest(int fd, const char *file, int digest_type, size_t *digest_lenp)
{
unsigned char *file_digest = NULL;
unsigned char buf[32 * 1024];
int fd2, gcry_digest_type;
size_t digest_len, nread;
gcry_error_t error;
gcry_md_hd_t ctx;
FILE *fp = NULL;
debug_decl(sudo_filedigest, SUDOERS_DEBUG_UTIL)
switch (digest_type) {
case SUDO_DIGEST_SHA224:
gcry_digest_type = GCRY_MD_SHA224;
break;
case SUDO_DIGEST_SHA256:
gcry_digest_type = GCRY_MD_SHA256;
break;
case SUDO_DIGEST_SHA384:
gcry_digest_type = GCRY_MD_SHA384;
break;
case SUDO_DIGEST_SHA512:
gcry_digest_type = GCRY_MD_SHA512;
break;
default:
sudo_warnx(U_("unsupported digest type %d for %s"), digest_type, file);
debug_return_ptr(NULL);
}
error = gcry_md_open(&ctx, gcry_digest_type, 0);
if (error != 0) {
sudo_warnx(U_("%s: %s"), digest_type_to_name(digest_type),
gcry_strerror(error));
goto bad;
}
digest_len = gcry_md_get_algo_dlen(gcry_digest_type);
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(digest_len)) == NULL) {
sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
goto bad;
}
while ((nread = fread(buf, 1, sizeof(buf), fp)) != 0) {
gcry_md_write(ctx, buf, nread);
}
if (ferror(fp)) {
sudo_warnx(U_("%s: read error"), file);
goto bad;
}
gcry_md_final(ctx);
fclose(fp);
memcpy(file_digest, gcry_md_read(ctx, 0), digest_len);
*digest_lenp = digest_len;
debug_return_ptr(file_digest);
bad:
free(file_digest);
gcry_md_close(ctx);
if (fp != NULL)
fclose(fp);
debug_return_ptr(NULL);
}