Add virtual hook to remove dep of Default_Engine on Engine itself

3 files changed, 14 insertions, 16 deletions

diff --git a/src/engine/def_engine/eng_def.h b/src/engine/def_engine/eng_def.h
index 36ef14a69..3d3fba809 100644
--- a/src/engine/def_engine/eng_def.h
+++ b/src/engine/def_engine/eng_def.h
@@ -55,6 +55,8 @@ class BOTAN_DLL Default_Engine : public Engine
       Modular_Exponentiator* mod_exp(const BigInt&,
                                      Power_Mod::Usage_Hints) const;
 
+      virtual bool can_add_algorithms() { return true; }
+
       Keyed_Filter* get_cipher(const std::string&, Cipher_Dir);
    private:
       BlockCipher* find_block_cipher(const std::string&) const;
diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index ce32fa3b4..75b49b6a6 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -7,7 +7,6 @@
 #include <botan/libstate.h>
 #include <botan/lookup.h>
 #include <botan/look_add.h>
-#include <botan/eng_def.h>
 
 namespace Botan {
 
@@ -287,10 +286,9 @@ void add_algorithm(Library_State& libstate, BlockCipher* algo)
    {
    Library_State::Engine_Iterator i(libstate);
 
-   while(Engine* engine_base = i.next())
+   while(Engine* engine = i.next())
       {
-      Default_Engine* engine = dynamic_cast<Default_Engine*>(engine_base);
-      if(engine)
+      if(engine->can_add_algorithms())
          {
          engine->add_algorithm(algo);
          return;
@@ -307,10 +305,9 @@ void add_algorithm(Library_State& libstate, StreamCipher* algo)
    {
    Library_State::Engine_Iterator i(libstate);
 
-   while(Engine* engine_base = i.next())
+   while(Engine* engine = i.next())
       {
-      Default_Engine* engine = dynamic_cast<Default_Engine*>(engine_base);
-      if(engine)
+      if(engine->can_add_algorithms())
          {
          engine->add_algorithm(algo);
          return;
@@ -327,10 +324,9 @@ void add_algorithm(Library_State& libstate, HashFunction* algo)
    {
    Library_State::Engine_Iterator i(libstate);
 
-   while(Engine* engine_base = i.next())
+   while(Engine* engine = i.next())
       {
-      Default_Engine* engine = dynamic_cast<Default_Engine*>(engine_base);
-      if(engine)
+      if(engine->can_add_algorithms())
          {
          engine->add_algorithm(algo);
          return;
@@ -348,10 +344,9 @@ void add_algorithm(Library_State& libstate,
    {
    Library_State::Engine_Iterator i(libstate);
 
-   while(Engine* engine_base = i.next())
+   while(Engine* engine = i.next())
       {
-      Default_Engine* engine = dynamic_cast<Default_Engine*>(engine_base);
-      if(engine)
+      if(engine->can_add_algorithms())
          {
          engine->add_algorithm(algo);
          return;
@@ -369,10 +364,9 @@ void add_algorithm(Library_State& libstate,
    {
    Library_State::Engine_Iterator i(libstate);
 
-   while(Engine* engine_base = i.next())
+   while(Engine* engine = i.next())
       {
-      Default_Engine* engine = dynamic_cast<Default_Engine*>(engine_base);
-      if(engine)
+      if(engine->can_add_algorithms())
          {
          engine->add_algorithm(algo);
          return;
diff --git a/src/engine/engine.h b/src/engine/engine.h
index d7fae2348..f21c67a79 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -122,6 +122,8 @@ class BOTAN_DLL Engine
       const class BlockCipherModePaddingMethod*
          bc_pad(const std::string&) const;
 
+      virtual bool can_add_algorithms() { return false; }
+
       void add_algorithm(BlockCipher*) const;
       void add_algorithm(StreamCipher*) const;
       void add_algorithm(HashFunction*) const;