[security] Fix buffer overflow.

src/inexact.c

@@ -6,8 +6,9 @@
  * and related and neighboring rights to this software to the public domain
  * worldwide. This software is distributed without any warranty.
  *
- * You should have received a copy of the CC0 Public Domain Dedication along with
- * this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
  */
 
 #include "inexact.h"
@@ -293,6 +294,11 @@ int get_seckey(const char *keyfile, unsigned char *skey, unsigned char *pkey) {
     /* max_size = base64(sizeof(curve25519_key)) = 64 * 4 / 3 + 1 -> 86 */
     unsigned char file_data[87] = {0};
 
+    if (sz > sizeof(file_data)) {
+        printf("Bad key size\n");
+        goto exit;
+    }
+
     size_t readed = fread(&file_data, 1, sz, fs);
     if (readed != sz) {
         printf("read file '%s' failed: %s.\n", keyfile, strerror(errno));
@@ -418,6 +424,12 @@ int get_pubkey(const char *keyfile, unsigned char *pkey) {
 
     /* max_size = base64(sizeof(curve25519_key)) = 32 * 4 / 3 + 1 -> 44 */
     unsigned char file_data[44] = {0};
+
+    if (sz > sizeof(file_data)) {
+        printf("Bad key size\n");
+        goto exit;
+    }
+
     size_t readed = fread(&file_data, 1, sz, fs);
     if (readed != sz) {
         printf("read file '%s' failed: %s.\n", keyfile, strerror(errno));

src/main.c

@@ -53,7 +53,7 @@ int main(int argc, char *argv[]) {
 
     int exitcode = 0;
     const char progname[] = "inexact";
-    const char ver[] = "beta 1.0";
+    const char ver[] = "beta 1.01";
     FILE *fo = NULL;
 
     int nerrors;