checkKey: handle NULL error string from OpenSSL more gracefully

fixes PowerDNS#10641
Habbie · Aug 10, 2021 · 843bc50 · 843bc50
1 parent c5f74c4
commit 843bc50
Showing 1 changed file with 10 additions and 2 deletions.
diff --git a/pdns/opensslsigners.cc b/pdns/opensslsigners.cc
@@ -491,7 +491,11 @@ bool OpenSSLRSADNSCryptoKeyEngine::checkKey(vector<string> *errorMessages) const
   if (RSA_check_key(d_key.get()) != 1) {
     retval = false;
     if (errorMessages != nullptr) {
-      errorMessages->push_back(ERR_reason_error_string(ERR_get_error()));
+      auto errmsg = ERR_reason_error_string(ERR_get_error());
+      if (errmsg == nullptr) {
+        errmsg = "Unknown OpenSSL error";
+      }
+      errorMessages->push_back(errmsg);
     }
   }
   return retval;
@@ -802,7 +806,11 @@ bool OpenSSLECDSADNSCryptoKeyEngine::checkKey(vector<string> *errorMessages) con
   if (EC_KEY_check_key(d_eckey.get()) != 1) {
     retval = false;
     if (errorMessages != nullptr) {
-      errorMessages->push_back(ERR_reason_error_string(ERR_get_error()));
+      auto errmsg = ERR_reason_error_string(ERR_get_error());
+      if (errmsg == nullptr) {
+        errmsg = "Unknown OpenSSL error";
+      }
+      errorMessages->push_back(errmsg);
     }
   }
   return retval;