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.

4 files changed, 28 insertions, 0 deletions

diff --git a/src/lib/stream/ctr/ctr.cpp b/src/lib/stream/ctr/ctr.cpp
index d025a03d3..e6d4b9d3e 100644
--- a/src/lib/stream/ctr/ctr.cpp
+++ b/src/lib/stream/ctr/ctr.cpp
@@ -7,6 +7,7 @@
 
 #include <botan/internal/stream_utils.h>
 #include <botan/ctr.h>
+#include <botan/lookup.h>
 
 namespace Botan {
 
diff --git a/src/lib/stream/ofb/ofb.cpp b/src/lib/stream/ofb/ofb.cpp
index 73ffef980..1979c676f 100644
--- a/src/lib/stream/ofb/ofb.cpp
+++ b/src/lib/stream/ofb/ofb.cpp
@@ -7,6 +7,7 @@
 
 #include <botan/internal/stream_utils.h>
 #include <botan/ofb.h>
+#include <botan/lookup.h>
 
 namespace Botan {
 
diff --git a/src/lib/stream/stream_cipher.cpp b/src/lib/stream/stream_cipher.cpp
index 2f1538914..3b8d35bc7 100644
--- a/src/lib/stream/stream_cipher.cpp
+++ b/src/lib/stream/stream_cipher.cpp
@@ -30,6 +30,18 @@
 
 namespace Botan {
 
+std::unique_ptr<StreamCipher> StreamCipher::create(const std::string& algo_spec,
+                                                   const std::string& provider)
+   {
+   return std::unique_ptr<StreamCipher>(make_a<StreamCipher>(algo_spec, provider));
+   }
+
+std::vector<std::string> StreamCipher::providers(const std::string& algo_spec)
+   {
+   return providers_of<StreamCipher>(StreamCipher::Spec(algo_spec));
+   }
+
+StreamCipher::StreamCipher() {}
 StreamCipher::~StreamCipher() {}
 
 void StreamCipher::set_iv(const byte[], size_t iv_len)
diff --git a/src/lib/stream/stream_cipher.h b/src/lib/stream/stream_cipher.h
index 5500bca49..68c97f1c1 100644
--- a/src/lib/stream/stream_cipher.h
+++ b/src/lib/stream/stream_cipher.h
@@ -23,6 +23,19 @@ class BOTAN_DLL StreamCipher : public SymmetricAlgorithm
       typedef SCAN_Name Spec;
 
       /**
+      * 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<StreamCipher> 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);
+
+      /**
       * Encrypt or decrypt a message
       * @param in the plaintext
       * @param out the byte array to hold the output, i.e. the ciphertext
@@ -68,6 +81,7 @@ class BOTAN_DLL StreamCipher : public SymmetricAlgorithm
       */
       virtual StreamCipher* clone() const = 0;
 
+      StreamCipher();
       virtual ~StreamCipher();
    };