GPG signatures have a timestamp which is checked and if it's in the
future, verification will fail.
Signed-off-by: Florian Pritz <bluewind(a)xinu.at>
---
Allan suggested to improve the error message printed when verification
fails, but since I already have this patch I can just as well submit it.
lib/libalpm/signing.c | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
diff --git a/lib/libalpm/signing.c b/lib/libalpm/signing.c
index 1e41716..6148976 100644
--- a/lib/libalpm/signing.c
+++ b/lib/libalpm/signing.c
@@ -20,6 +20,8 @@
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
+#include <time.h>
+#include <errno.h>
#if HAVE_LIBGPGME
#include <locale.h> /* setlocale() */
@@ -127,6 +129,10 @@ static int init_gpgme(alpm_handle_t *handle)
gpgme_error_t err;
gpgme_engine_info_t enginfo;
+ const static char *timestamp_file = "timestamp";
+ int len;
+ char *timestamp_path;
+
if(init) {
/* we already successfully initialized the library */
return 0;
@@ -143,6 +149,34 @@ static int init_gpgme(alpm_handle_t *handle)
"pacman-key --init");
}
+ len = strlen(sigdir) + strlen(timestamp_file) + 1;
+ CALLOC(timestamp_path, len, sizeof(char), RET_ERR(handle, ALPM_ERR_MEMORY, -1));
+ snprintf(timestamp_path, len, "%s%s", sigdir, timestamp_file);
+
+ /* check if time went backwards since last run */
+ if(!_alpm_access(handle, sigdir, timestamp_file, F_OK)) {
+ struct stat sb;
+ time_t t;
+
+ if(stat(timestamp_path, &sb) == -1) {
+ /* TODO: should we really error here? */
+ RET_ERR(handle, ALPM_ERR_SYSTEM, -1);
+ }
+
+ t = time(NULL);
+ if(t == ((time_t)-1)) {
+ _alpm_log(handle, ALPM_LOG_ERROR, _("Failed to determine system time: %s\n"), strerror(errno));
+ }
+
+ if(sb.st_mtime > t) {
+ _alpm_log(handle, ALPM_LOG_WARNING, _("Time went backwards, signature verification might fail.\n"));
+ }
+ }
+ /* create file if missing, else update timestamp */
+ close(creat(timestamp_path, O_RDWR));
+
+ free(timestamp_path);
+
/* calling gpgme_check_version() returns the current version and runs
* some internal library setup code */
version = gpgme_check_version(NULL);
--
1.7.11.1