From 836328be2e9a8ede43b075bae73426ce4ffcb60c Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Thu, 17 May 2007 01:52:26 +0000
Subject: [PATCH]  r12777@catbus:  nickm | 2007-05-16 21:52:23 -0400  Fix dumb
 bug introduced in r10199

svn:r10202
---
 src/common/crypto.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/common/crypto.c b/src/common/crypto.c
index 4bb58f2d76..40cb5fafae 100644
--- a/src/common/crypto.c
+++ b/src/common/crypto.c
@@ -1494,12 +1494,14 @@ crypto_expand_key_material(const char *key_in, size_t key_in_len,
   tor_assert(key_out_len <= DIGEST_LEN*256);
 
   memcpy(tmp, key_in, key_in_len);
-  for (cp = key_out, i=0; key_out_len >= DIGEST_LEN;
+  for (cp = key_out, i=0; key_out_len;
        ++i, cp += DIGEST_LEN, key_out_len -= DIGEST_LEN) {
     tmp[key_in_len] = i;
     if (crypto_digest(digest, tmp, key_in_len+1))
       goto err;
     memcpy(cp, digest, MIN(DIGEST_LEN, key_out_len));
+    if (key_out_len < DIGEST_LEN)
+      break;
   }
   memset(tmp, 0, key_in_len+1);
   tor_free(tmp);