Add a runtime map of string->func() which when called return

Transforms and BlockCiphers. Registration for all types is done at
startup but is very cheap as just a std::function and a std::map entry
are created, no actual objects are created until needed. This is a
huge improvement over Algorithm_Factory which used T::clone() as the
function and thus kept a prototype object of each type in memory.

Replace existing lookup mechanisms for ciphers, AEADs, and compression
to use the transform lookup. The existing Engine framework remains in
place for BlockCipher, but the engines now just call to the registry
instead of having hardcoded lookups.

s/Transformation/Transform/ with typedefs for compatability.

Remove lib/selftest code (for runtime selftesting): not the right approach.

1 files changed, 17 insertions, 42 deletions

diff --git a/src/lib/compression/compression.cpp b/src/lib/compression/compression.cpp
index 428271e9a..e5221aba6 100644
--- a/src/lib/compression/compression.cpp
+++ b/src/lib/compression/compression.cpp
@@ -6,67 +6,42 @@
 */
 
 #include <botan/compression.h>
-
-#if defined(BOTAN_HAS_ZLIB_TRANSFORM)
-  #include <botan/zlib.h>
-#endif
-
-#if defined(BOTAN_HAS_BZIP2_TRANSFORM)
-  #include <botan/bzip2.h>
-#endif
-
-#if defined(BOTAN_HAS_LZMA_TRANSFORM)
-  #include <botan/lzma.h>
-#endif
+#include <botan/algo_registry.h>
 
 namespace Botan {
 
-Compressor_Transformation* make_compressor(const std::string& type, size_t level)
+Transform* make_compressor(const std::string& type, size_t level)
    {
-#if defined(BOTAN_HAS_ZLIB_TRANSFORM)
+   const std::string comp_suffix = "_Compression(" + std::to_string(level) + ")";
+
    if(type == "zlib")
-      return new Zlib_Compression(level);
+      return get_transform("Zlib" + comp_suffix);
    if(type == "deflate")
-      return new Deflate_Compression(level);
+      return get_transform("Deflate" + comp_suffix);
    if(type == "gzip" || type == "gz")
-      return new Gzip_Compression(level);
-#endif
-
-#if defined(BOTAN_HAS_BZIP2_TRANSFORM)
+      return get_transform("Gzip" + comp_suffix);
    if(type == "bzip2" || type == "bz2")
-      return new Bzip2_Compression(level);
-#endif
-
-#if defined(BOTAN_HAS_LZMA_TRANSFORM)
+      return get_transform("Bzip2", comp_suffix);
    if(type == "lzma" || type == "xz")
-      return new LZMA_Compression(level);
-#endif
+      return get_transform("LZMA", comp_suffix);
 
-   throw std::runtime_error("Unknown compression type " + type);
+   return nullptr;
    }
 
-Compressor_Transformation* make_decompressor(const std::string& type)
+Transform* make_decompressor(const std::string& type)
    {
-#if defined(BOTAN_HAS_ZLIB_TRANSFORM)
    if(type == "zlib")
-      return new Zlib_Decompression;
+      return get_transform("Zlib_Decompression");
    if(type == "deflate")
-      return new Deflate_Decompression;
+      return get_transform("Deflate_Decompression");
    if(type == "gzip" || type == "gz")
-      return new Gzip_Decompression;
-#endif
-
-#if defined(BOTAN_HAS_BZIP2_TRANSFORM)
+      return get_transform("Gzip_Decompression");
    if(type == "bzip2" || type == "bz2")
-      return new Bzip2_Decompression;
-#endif
-
-#if defined(BOTAN_HAS_LZMA_TRANSFORM)
+      return get_transform("Bzip2_Decompression");
    if(type == "lzma" || type == "xz")
-      return new LZMA_Decompression;
-#endif
+      return get_transform("LZMA_Decompression");
 
-   throw std::runtime_error("Unknown compression type " + type);
+   return nullptr;
    }
 
 void Stream_Compression::clear()