1 files changed, 182 insertions, 0 deletions
diff --git a/src/lib/base/transform.h b/src/lib/base/transform.h
new file mode 100644
index 000000000..75bd5004a
--- /dev/null
+++ b/src/lib/base/transform.h
@@ -0,0 +1,182 @@
+/*
+* Transforms of data
+* (C) 2013 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_TRANSFORM_H__
+#define BOTAN_TRANSFORM_H__
+
+#include <botan/secmem.h>
+#include <botan/key_spec.h>
+#include <botan/exceptn.h>
+#include <botan/symkey.h>
+#include <botan/scan_name.h>
+#include <string>
+#include <vector>
+
+namespace Botan {
+
+/**
+* Interface for general transformations on data
+*/
+class BOTAN_DLL Transform
+   {
+   public:
+      typedef SCAN_Name Spec;
+
+      /**
+      * Begin processing a message.
+      * @param nonce the per message nonce
+      */
+      template<typename Alloc>
+      secure_vector<byte> start(const std::vector<byte, Alloc>& nonce)
+         {
+         return start(&nonce[0], nonce.size());
+         }
+
+      /**
+      * Begin processing a message.
+      * @param nonce the per message nonce
+      */
+      template<typename Alloc>
+      BOTAN_DEPRECATED("Use Transform::start")
+      secure_vector<byte> start_vec(const std::vector<byte, Alloc>& nonce)
+         {
+         return start(&nonce[0], nonce.size());
+         }
+
+      /**
+      * Begin processing a message.
+      * @param nonce the per message nonce
+      * @param nonce_len length of nonce
+      */
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len)
+         {
+         return start_raw(nonce, nonce_len);
+         }
+
+      /**
+      * Begin processing a message.
+      */
+      secure_vector<byte> start()
+         {
+         return start_raw(nullptr, 0);
+         }
+
+      virtual secure_vector<byte> start_raw(const byte nonce[], size_t nonce_len) = 0;
+
+      /**
+      * Process some data. Input must be in size update_granularity() byte blocks.
+      * @param blocks in/out paramter which will possibly be resized
+      * @param offset an offset into blocks to begin processing
+      */
+      virtual void update(secure_vector<byte>& blocks, size_t offset = 0) = 0;
+
+      /**
+      * Complete processing of a message.
+      *
+      * @param final_block in/out parameter which must be at least
+      *        minimum_final_size() bytes, and will be set to any final output
+      * @param offset an offset into final_block to begin processing
+      */
+      virtual void finish(secure_vector<byte>& final_block, size_t offset = 0) = 0;
+
+      /**
+      * Returns the size of the output if this transform is used to process a
+      * message with input_length bytes. Will throw if unable to give a precise
+      * answer.
+      */
+      virtual size_t output_length(size_t input_length) const = 0;
+
+      /**
+      * @return size of required blocks to update
+      */
+      virtual size_t update_granularity() const = 0;
+
+      /**
+      * @return required minimium size to finalize() - may be any
+      *         length larger than this.
+      */
+      virtual size_t minimum_final_size() const = 0;
+
+      /**
+      * Return the default size for a nonce
+      */
+      virtual size_t default_nonce_length() const = 0;
+
+      /**
+      * Return true iff nonce_len is a valid length for the nonce
+      */
+      virtual bool valid_nonce_length(size_t nonce_len) const = 0;
+
+      /**
+      * Return some short name describing the provider of this tranformation.
+      * Useful in cases where multiple implementations are available (eg,
+      * different implementations of AES). Default "core" is used for the
+      * 'standard' implementation included in the library.
+      */
+      virtual std::string provider() const { return "core"; }
+
+      virtual std::string name() const = 0;
+
+      virtual void clear() = 0;
+
+      virtual ~Transform() {}
+   };
+
+class BOTAN_DLL Keyed_Transform : public Transform
+   {
+   public:
+      /**
+      * @return object describing limits on key size
+      */
+      virtual Key_Length_Specification key_spec() const = 0;
+
+      /**
+      * Check whether a given key length is valid for this algorithm.
+      * @param length the key length to be checked.
+      * @return true if the key length is valid.
+      */
+      bool valid_keylength(size_t length) const
+         {
+         return key_spec().valid_keylength(length);
+         }
+
+      template<typename Alloc>
+      void set_key(const std::vector<byte, Alloc>& key)
+         {
+         set_key(&key[0], key.size());
+         }
+
+      void set_key(const SymmetricKey& key)
+         {
+         set_key(key.begin(), key.length());
+         }
+
+      /**
+      * Set the symmetric key of this transform
+      * @param key contains the key material
+      * @param length in bytes of key param
+      */
+      void set_key(const byte key[], size_t length)
+         {
+         if(!valid_keylength(length))
+            throw Invalid_Key_Length(name(), length);
+         key_schedule(key, length);
+         }
+
+   private:
+      virtual void key_schedule(const byte key[], size_t length) = 0;
+   };
+
+typedef Transform Transformation;
+
+BOTAN_DLL Transform* get_transform(const std::string& specstr,
+                                   const std::string& provider = "",
+                                   const std::string& dirstr = "");
+
+}
+
+#endif