Handle dependencies re static linking. GH #279

Previously we were hanging on the type destructors to pull in
the relevant objects. However that fails in many simple cases
where the object is never deleted.

For every type involved in the algo registry add static create
and providers functions to access the algo registry. Modify
lookup.h to be inline and call those functions, and move
a few to sub-headers (eg, get_pbkdf going to pbkdf.h). So
accessing the registry involves going through the same file
that handles the initialization, so there is no way to end up
with missing objs.

1 files changed, 24 insertions, 4 deletions

diff --git a/src/lib/kdf/kdf.cpp b/src/lib/kdf/kdf.cpp
index 836e9b982..3eba8a5cd 100644
--- a/src/lib/kdf/kdf.cpp
+++ b/src/lib/kdf/kdf.cpp
@@ -6,7 +6,7 @@
 */
 
 #include <botan/kdf.h>
-#include <botan/internal/kdf_utils.h>
+#include <botan/internal/algo_registry.h>
 
 #if defined(BOTAN_HAS_HKDF)
 #include <botan/hkdf.h>
@@ -32,10 +32,29 @@
 #include <botan/prf_x942.h>
 #endif
 
+#define BOTAN_REGISTER_KDF_NOARGS(type, name)                    \
+   BOTAN_REGISTER_NAMED_T(KDF, name, type, (make_new_T<type>))
+#define BOTAN_REGISTER_KDF_1HASH(type, name)                    \
+   BOTAN_REGISTER_NAMED_T(KDF, name, type, (make_new_T_1X<type, HashFunction>))
+
+#define BOTAN_REGISTER_KDF_NAMED_1STR(type, name) \
+   BOTAN_REGISTER_NAMED_T(KDF, name, type, (make_new_T_1str_req<type>))
+
 namespace Botan {
 
 KDF::~KDF() {}
 
+std::unique_ptr<KDF> KDF::create(const std::string& algo_spec,
+                                                 const std::string& provider)
+   {
+   return std::unique_ptr<KDF>(make_a<KDF>(algo_spec, provider));
+   }
+
+std::vector<std::string> KDF::providers(const std::string& algo_spec)
+   {
+   return providers_of<KDF>(KDF::Spec(algo_spec));
+   }
+
 KDF* get_kdf(const std::string& algo_spec)
    {
    SCAN_Name request(algo_spec);
@@ -43,9 +62,10 @@ KDF* get_kdf(const std::string& algo_spec)
    if(request.algo_name() == "Raw")
       return nullptr; // No KDF
 
-   if(KDF* kdf = make_a<KDF>(algo_spec))
-      return kdf;
-   throw Algorithm_Not_Found(algo_spec);
+   auto kdf = KDF::create(algo_spec);
+   if(!kdf)
+      throw Algorithm_Not_Found(algo_spec);
+   return kdf.release();
    }
 
 #if defined(BOTAN_HAS_HKDF)