From e75069f79aa6b8a61034a9a4db9b6265b8be8ae4 Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Fri, 22 Jan 2021 22:50:25 +0000
Subject: [PATCH] Tidy initialisation in hash_questions.c

---
 src/dnsmasq.c        |  2 +-
 src/dnsmasq.h        |  1 +
 src/hash_questions.c | 32 ++++++++++++++++----------------
 3 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/src/dnsmasq.c b/src/dnsmasq.c
index 2306c48..14c66f6 100644
--- a/src/dnsmasq.c
+++ b/src/dnsmasq.c
@@ -390,8 +390,8 @@ int main (int argc, char **argv)
   if (daemon->port != 0)
     {
       cache_init();
-
       blockdata_init();
+      hash_questions_init();
     }
 
 #ifdef HAVE_INOTIFY
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index 360c226..8493285 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -1261,6 +1261,7 @@ size_t filter_rrsigs(struct dns_header *header, size_t plen);
 int setup_timestamp(void);
 
 /* hash_questions.c */
+void hash_questions_init(void);
 unsigned char *hash_questions(struct dns_header *header, size_t plen, char *name);
 
 /* crypto.c */
diff --git a/src/hash_questions.c b/src/hash_questions.c
index 51d88c2..fad32d7 100644
--- a/src/hash_questions.c
+++ b/src/hash_questions.c
@@ -29,27 +29,24 @@
 #include "dnsmasq.h"
 
 #if defined(HAVE_DNSSEC) || defined(HAVE_NETTLEHASH)
+
+static const struct nettle_hash *hash;
+static void *ctx;
+static unsigned char *digest;
+
+void hash_questions_init(void)
+{
+  if (!(hash = hash_find("sha256")) || !hash_init(hash, &ctx, &digest))
+    die(_("Failed to create SHA-256 hash object"), NULL, EC_MISC);
+}
+
 unsigned char *hash_questions(struct dns_header *header, size_t plen, char *name)
 {
   int q;
   unsigned char *p = (unsigned char *)(header+1);
-  const struct nettle_hash *hash;
-  void *ctx;
-  unsigned char *digest;
-  
-  if (!(hash = hash_find("sha256")) || !hash_init(hash, &ctx, &digest))
-    {
-      /* don't think this can ever happen. */
-      static unsigned char dummy[HASH_SIZE];
-      static int warned = 0;
 
-      if (!warned)
-	my_syslog(LOG_ERR, _("Failed to create SHA-256 hash object"));
-      warned = 1;
-     
-      return dummy;
-    }
-  
+  hash->init(ctx);
+
   for (q = ntohs(header->qdcount); q != 0; q--) 
     {
       char *cp, c;
@@ -91,6 +88,9 @@ static void sha256_init(SHA256_CTX *ctx);
 static void sha256_update(SHA256_CTX *ctx, const BYTE data[], size_t len);
 static void sha256_final(SHA256_CTX *ctx, BYTE hash[]);
 
+void hash_questions_init(void)
+{
+}
 
 unsigned char *hash_questions(struct dns_header *header, size_t plen, char *name)
 {