1 files changed, 68 insertions, 0 deletions
diff --git a/src/buf_filt.cpp b/src/buf_filt.cpp
new file mode 100644
index 000000000..a6df82074
--- /dev/null
+++ b/src/buf_filt.cpp
@@ -0,0 +1,68 @@
+/*************************************************
+* Buffering Filter Source File                   *
+* (C) 1999-2006 The Botan Project                *
+*************************************************/
+
+#include <botan/buf_filt.h>
+#include <algorithm>
+
+namespace Botan {
+
+/*************************************************
+* Buffering_Filter Constructor                   *
+*************************************************/
+Buffering_Filter::Buffering_Filter(u32bit b, u32bit i) : INITIAL_BLOCK_SIZE(i),
+                                                         BLOCK_SIZE(b)
+   {
+   initial_block_pos = block_pos = 0;
+   initial.create(INITIAL_BLOCK_SIZE);
+   block.create(BLOCK_SIZE);
+   }
+
+/*************************************************
+* Reset the Buffering Filter                     *
+*************************************************/
+void Buffering_Filter::end_msg()
+   {
+   if(initial_block_pos != INITIAL_BLOCK_SIZE)
+      throw Exception("Buffering_Filter: Not enough data for first block");
+   final_block(block, block_pos);
+   initial_block_pos = block_pos = 0;
+   initial.clear();
+   block.clear();
+   }
+
+/*************************************************
+* Buffer input into blocks                       *
+*************************************************/
+void Buffering_Filter::write(const byte input[], u32bit length)
+   {
+   if(initial_block_pos != INITIAL_BLOCK_SIZE)
+      {
+      u32bit copied = std::min(INITIAL_BLOCK_SIZE - initial_block_pos, length);
+      initial.copy(initial_block_pos, input, copied);
+      input += copied;
+      length -= copied;
+      initial_block_pos += copied;
+      if(initial_block_pos == INITIAL_BLOCK_SIZE)
+         initial_block(initial);
+      }
+   block.copy(block_pos, input, length);
+   if(block_pos + length >= BLOCK_SIZE)
+      {
+      main_block(block);
+      input += (BLOCK_SIZE - block_pos);
+      length -= (BLOCK_SIZE - block_pos);
+      while(length >= BLOCK_SIZE)
+         {
+         main_block(input);
+         input += BLOCK_SIZE;
+         length -= BLOCK_SIZE;
+         }
+      block.copy(input, length);
+      block_pos = 0;
+      }
+   block_pos += length;
+   }
+
+}