From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Wed, 6 Jan 2021 09:25:12 +0000 (+0100)
Subject: Only call std::string::reserve() when needed in hashQNameWithSalt()
X-Git-Tag: dnsdist-1.6.0-alpha1^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a2e730183d4a5dec3c601f8228ce9bb22f241598;p=thirdparty%2Fpdns.git

Only call std::string::reserve() when needed in hashQNameWithSalt()
---

diff --git a/pdns/dnssecinfra.cc b/pdns/dnssecinfra.cc
index 152fd3bf80..110f5f1dfa 100644
--- a/pdns/dnssecinfra.cc
+++ b/pdns/dnssecinfra.cc
@@ -494,9 +494,6 @@ string hashQNameWithSalt(const std::string& salt, unsigned int iterations, const
   unsigned int times = iterations;
   unsigned char hash[SHA_DIGEST_LENGTH];
   string toHash(qname.toDNSStringLC() + salt);
-  if (toHash.capacity() < (salt.size() + sizeof(hash))) {
-    toHash.reserve(salt.size() + sizeof(hash));
-  }
 
   for (;;) {
     /* so the first time we hash the (lowercased) qname plus the salt,
@@ -511,6 +508,9 @@ string hashQNameWithSalt(const std::string& salt, unsigned int iterations, const
       /* first time, we need to replace the qname + salt with
          the hash plus salt, since the qname will not likely
          match the size of the hash */
+      if (toHash.capacity() < (sizeof(hash) + salt.size())) {
+        toHash.reserve(sizeof(hash) + salt.size());
+      }
       toHash.assign(reinterpret_cast<char*>(hash), sizeof(hash));
       toHash.append(salt);
     }