Add a facility in SCAN_Name for provider names

1 files changed, 24 insertions, 2 deletions

diff --git a/src/utils/scan_name.cpp b/src/utils/scan_name.cpp
index 91d017811..77e15fa07 100644
--- a/src/utils/scan_name.cpp
+++ b/src/utils/scan_name.cpp
@@ -10,12 +10,34 @@ SCAN Name Abstraction
 
 namespace Botan {
 
-SCAN_Name::SCAN_Name(const std::string& algo_spec)
+SCAN_Name::SCAN_Name(const std::string& algo_spec,
+                     const std::string& prov_names)
    {
    name = parse_algorithm_name(algo_spec);
-
    for(u32bit i = 0; i != name.size(); ++i)
       name[i] = global_state().deref_alias(name[i]);
+
+   if(prov_names.find(',') != std::string::npos)
+      {
+      std::vector<std::string> prov_names_vec = split_on(prov_names, ',');
+      for(u32bit i = 0; i != prov_names_vec.size(); ++i)
+         providers.insert(prov_names_vec[i]);
+      }
+   else if(prov_names != "")
+      providers.insert(prov_names);
+   }
+
+bool SCAN_Name::provider_allowed(const std::string& provider) const
+   {
+   // If not providers were specified by the user, then allow any;
+   // usually the source order will try to perfer one of the better
+   // ones first.
+
+   // The core provider is always enabled
+   if(provider == "core" || providers.empty())
+      return true;
+
+   return (providers.find(provider) != providers.end());
    }
 
 std::string SCAN_Name::argument(u32bit i) const