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.

9 files changed, 41 insertions, 41 deletions

diff --git a/src/lib/kdf/hkdf/hkdf.cpp b/src/lib/kdf/hkdf/hkdf.cpp
index df6e49fad..d4c688afc 100644
--- a/src/lib/kdf/hkdf/hkdf.cpp
+++ b/src/lib/kdf/hkdf/hkdf.cpp
@@ -5,8 +5,8 @@
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
-#include <botan/internal/kdf_utils.h>
 #include <botan/hkdf.h>
+#include <botan/lookup.h>
 
 namespace Botan {
 
diff --git a/src/lib/kdf/info.txt b/src/lib/kdf/info.txt
index 35032e159..68aa46895 100644
--- a/src/lib/kdf/info.txt
+++ b/src/lib/kdf/info.txt
@@ -7,7 +7,3 @@ base
 <header:public>
 kdf.h
 </header:public>
-
-<header:internal>
-kdf_utils.h
-</header:internal>
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)
diff --git a/src/lib/kdf/kdf.h b/src/lib/kdf/kdf.h
index 936e7c5f1..a8d4650e0 100644
--- a/src/lib/kdf/kdf.h
+++ b/src/lib/kdf/kdf.h
@@ -23,6 +23,19 @@ class BOTAN_DLL KDF
    public:
       virtual ~KDF();
 
+      /**
+      * Create an instance based on a name
+      * Will return a null pointer if the algo/provider combination cannot
+      * be found. If providers is empty then best available is chosen.
+      */
+      static std::unique_ptr<KDF> create(const std::string& algo_spec,
+                                         const std::string& provider = "");
+
+      /**
+      * Returns the list of available providers for this algorithm, empty if not available
+      */
+      static std::vector<std::string> providers(const std::string& algo_spec);
+
       virtual std::string name() const = 0;
 
       virtual size_t kdf(byte key[], size_t key_len,
diff --git a/src/lib/kdf/kdf1/kdf1.cpp b/src/lib/kdf/kdf1/kdf1.cpp
index c87bacd27..c7ea3c37e 100644
--- a/src/lib/kdf/kdf1/kdf1.cpp
+++ b/src/lib/kdf/kdf1/kdf1.cpp
@@ -5,7 +5,6 @@
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
-#include <botan/internal/kdf_utils.h>
 #include <botan/kdf1.h>
 
 namespace Botan {
diff --git a/src/lib/kdf/kdf2/kdf2.cpp b/src/lib/kdf/kdf2/kdf2.cpp
index 1b1c3638a..df2b7a91c 100644
--- a/src/lib/kdf/kdf2/kdf2.cpp
+++ b/src/lib/kdf/kdf2/kdf2.cpp
@@ -5,7 +5,6 @@
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
-#include <botan/internal/kdf_utils.h>
 #include <botan/kdf2.h>
 
 namespace Botan {
diff --git a/src/lib/kdf/kdf_utils.h b/src/lib/kdf/kdf_utils.h
deleted file mode 100644
index f67892437..000000000
--- a/src/lib/kdf/kdf_utils.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
-* KDF Utility Header
-* (C) 2015 Jack Lloyd
-*
-* Botan is released under the Simplified BSD License (see license.txt)
-*/
-
-#ifndef BOTAN_KDF_UTILS_H__
-#define BOTAN_KDF_UTILS_H__
-
-#include <botan/kdf.h>
-#include <botan/internal/algo_registry.h>
-#include <botan/exceptn.h>
-#include <botan/internal/xor_buf.h>
-
-namespace Botan {
-
-#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>))
-
-}
-
-#endif
diff --git a/src/lib/kdf/prf_tls/prf_tls.cpp b/src/lib/kdf/prf_tls/prf_tls.cpp
index ef130d5ba..08a2a0899 100644
--- a/src/lib/kdf/prf_tls/prf_tls.cpp
+++ b/src/lib/kdf/prf_tls/prf_tls.cpp
@@ -5,9 +5,10 @@
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
-#include <botan/internal/kdf_utils.h>
 #include <botan/prf_tls.h>
 #include <botan/hmac.h>
+#include <botan/lookup.h>
+#include <botan/internal/xor_buf.h>
 
 namespace Botan {
 
diff --git a/src/lib/kdf/prf_x942/prf_x942.cpp b/src/lib/kdf/prf_x942/prf_x942.cpp
index e8f234e49..443e207f2 100644
--- a/src/lib/kdf/prf_x942/prf_x942.cpp
+++ b/src/lib/kdf/prf_x942/prf_x942.cpp
@@ -5,12 +5,12 @@
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
-#include <botan/internal/kdf_utils.h>
 #include <botan/prf_x942.h>
 #include <botan/der_enc.h>
 #include <botan/oids.h>
 #include <botan/hash.h>
 #include <botan/loadstor.h>
+#include <botan/lookup.h>
 #include <algorithm>
 
 namespace Botan {