Convert compression filters to in-place transforms and refactor

to minimize the amount of logic needed in the files specific to each
library.

1 files changed, 99 insertions, 0 deletions

diff --git a/src/lib/compression/compression.h b/src/lib/compression/compression.h
new file mode 100644
index 000000000..10c7f1a64
--- /dev/null
+++ b/src/lib/compression/compression.h
@@ -0,0 +1,99 @@
+/*
+* Compression Transform
+* (C) 2014 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_COMPRESSION_TRANSFORM_H__
+#define BOTAN_COMPRESSION_TRANSFORM_H__
+
+#include <botan/transform.h>
+
+namespace Botan {
+
+class BOTAN_DLL Compressor_Transformation : public Transformation
+   {
+   public:
+      size_t update_granularity() const override { return 1; }
+
+      size_t minimum_final_size() const override { return 0; }
+
+      size_t default_nonce_length() const override { return 0; }
+
+      bool valid_nonce_length(size_t nonce_len) const override
+         { return nonce_len == 0; }
+
+      virtual void flush(secure_vector<byte>& buf, size_t offset = 0) { update(buf, offset); }
+
+      size_t output_length(size_t) const override
+         {
+         throw std::runtime_error(name() + " output length indeterminate");
+         }
+   };
+
+class Compression_Stream
+   {
+   public:
+      virtual ~Compression_Stream() {}
+
+      virtual void next_in(byte* b, size_t len) = 0;
+
+      virtual void next_out(byte* b, size_t len) = 0;
+
+      virtual size_t avail_in() const = 0;
+
+      virtual size_t avail_out() const = 0;
+
+      virtual u32bit run_flag() const = 0;
+      virtual u32bit flush_flag() const = 0;
+      virtual u32bit finish_flag() const = 0;
+
+      virtual bool run(u32bit flags) = 0;
+   };
+
+class BOTAN_DLL Stream_Compression : public Compressor_Transformation
+   {
+   public:
+      void update(secure_vector<byte>& buf, size_t offset = 0) override;
+
+      void flush(secure_vector<byte>& buf, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& buf, size_t offset = 0) override;
+
+      void clear() override;
+
+   private:
+      secure_vector<byte> start_raw(const byte[], size_t) override;
+
+      void process(secure_vector<byte>& buf, size_t offset, u32bit flags);
+
+      virtual Compression_Stream* make_stream() const = 0;
+
+      secure_vector<byte> m_buffer;
+      std::unique_ptr<Compression_Stream> m_stream;
+   };
+
+class BOTAN_DLL Stream_Decompression : public Compressor_Transformation
+   {
+   public:
+      void update(secure_vector<byte>& buf, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& buf, size_t offset = 0) override;
+
+      void clear() override;
+
+   private:
+      secure_vector<byte> start_raw(const byte[], size_t) override;
+
+      void process(secure_vector<byte>& buf, size_t offset, u32bit flags);
+
+      virtual Compression_Stream* make_stream() const = 0;
+
+      secure_vector<byte> m_buffer;
+      std::unique_ptr<Compression_Stream> m_stream;
+   };
+
+}
+
+#endif