From 09729861646bbcf842e830789e3a0173b6cdb7c2 Mon Sep 17 00:00:00 2001
From: Karol Babioch <karol@babioch.de>
Date: Thu, 17 May 2018 16:03:21 +0200
Subject: [PATCH] util.c: Check whether generate_random() was invoked
 successfully

This evaluates the return code from generate_random() within
write_chalresp_state() and returns immediately in case of an error.

This fixes #161.
---
 util.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/util.c b/util.c
index a9a6fe6..2e52651 100644
--- a/util.c
+++ b/util.c
@@ -508,7 +508,10 @@ write_chalresp_state(FILE *f, CR_STATE *state)
     iterations = state->iterations;
   }
 
-  generate_random(salt, CR_SALT_SIZE);
+  if (generate_random(salt, CR_CHALLENGE_SIZE)) {
+    goto out;
+  }
+
   yk_pbkdf2(response_hex, salt, CR_SALT_SIZE, iterations,
       hash, CR_RESPONSE_SIZE, &prf_method);