1 files changed, 157 insertions, 0 deletions
diff --git a/src/modes/cbc/cbc.cpp b/src/modes/cbc/cbc.cpp
new file mode 100644
index 000000000..9ad598bed
--- /dev/null
+++ b/src/modes/cbc/cbc.cpp
@@ -0,0 +1,157 @@
+/*************************************************
+* CBC Mode Source File                           *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/cbc.h>
+#include <botan/lookup.h>
+#include <botan/xor_buf.h>
+#include <algorithm>
+
+namespace Botan {
+
+/*************************************************
+* CBC Encryption Constructor                     *
+*************************************************/
+CBC_Encryption::CBC_Encryption(const std::string& cipher_name,
+                               const std::string& padding_name) :
+   BlockCipherMode(cipher_name, "CBC", block_size_of(cipher_name)),
+   padder(get_bc_pad(padding_name))
+   {
+   if(!padder->valid_blocksize(BLOCK_SIZE))
+      throw Invalid_Block_Size(name(), padder->name());
+   }
+
+/*************************************************
+* CBC Encryption Constructor                     *
+*************************************************/
+CBC_Encryption::CBC_Encryption(const std::string& cipher_name,
+                               const std::string& padding_name,
+                               const SymmetricKey& key,
+                               const InitializationVector& iv) :
+   BlockCipherMode(cipher_name, "CBC", block_size_of(cipher_name)),
+   padder(get_bc_pad(padding_name))
+   {
+   if(!padder->valid_blocksize(BLOCK_SIZE))
+      throw Invalid_Block_Size(name(), padder->name());
+   set_key(key);
+   set_iv(iv);
+   }
+
+/*************************************************
+* Encrypt in CBC mode                            *
+*************************************************/
+void CBC_Encryption::write(const byte input[], u32bit length)
+   {
+   while(length)
+      {
+      u32bit xored = std::min(BLOCK_SIZE - position, length);
+      xor_buf(state + position, input, xored);
+      input += xored;
+      length -= xored;
+      position += xored;
+      if(position == BLOCK_SIZE)
+         {
+         cipher->encrypt(state);
+         send(state, BLOCK_SIZE);
+         position = 0;
+         }
+      }
+   }
+
+/*************************************************
+* Finish encrypting in CBC mode                  *
+*************************************************/
+void CBC_Encryption::end_msg()
+   {
+   SecureVector<byte> padding(BLOCK_SIZE);
+   padder->pad(padding, padding.size(), position);
+   write(padding, padder->pad_bytes(BLOCK_SIZE, position));
+   if(position != 0)
+      throw Exception(name() + ": Did not pad to full blocksize");
+   }
+
+/*************************************************
+* Return a CBC mode name                         *
+*************************************************/
+std::string CBC_Encryption::name() const
+   {
+   return (cipher->name() + "/" + mode_name + "/" + padder->name());
+   }
+
+/*************************************************
+* CBC Decryption Constructor                     *
+*************************************************/
+CBC_Decryption::CBC_Decryption(const std::string& cipher_name,
+                               const std::string& padding_name) :
+   BlockCipherMode(cipher_name, "CBC", block_size_of(cipher_name)),
+   padder(get_bc_pad(padding_name))
+   {
+   if(!padder->valid_blocksize(BLOCK_SIZE))
+      throw Invalid_Block_Size(name(), padder->name());
+   temp.create(BLOCK_SIZE);
+   }
+
+/*************************************************
+* CBC Decryption Constructor                     *
+*************************************************/
+CBC_Decryption::CBC_Decryption(const std::string& cipher_name,
+                               const std::string& padding_name,
+                               const SymmetricKey& key,
+                               const InitializationVector& iv) :
+   BlockCipherMode(cipher_name, "CBC", block_size_of(cipher_name)),
+   padder(get_bc_pad(padding_name))
+   {
+   if(!padder->valid_blocksize(BLOCK_SIZE))
+      throw Invalid_Block_Size(name(), padder->name());
+   temp.create(BLOCK_SIZE);
+   set_key(key);
+   set_iv(iv);
+   }
+
+/*************************************************
+* Decrypt in CBC mode                            *
+*************************************************/
+void CBC_Decryption::write(const byte input[], u32bit length)
+   {
+   while(length)
+      {
+      if(position == BLOCK_SIZE)
+         {
+         cipher->decrypt(buffer, temp);
+         xor_buf(temp, state, BLOCK_SIZE);
+         send(temp, BLOCK_SIZE);
+         state = buffer;
+         position = 0;
+         }
+      u32bit added = std::min(BLOCK_SIZE - position, length);
+      buffer.copy(position, input, added);
+      input += added;
+      length -= added;
+      position += added;
+      }
+   }
+
+/*************************************************
+* Finish decrypting in CBC mode                  *
+*************************************************/
+void CBC_Decryption::end_msg()
+   {
+   if(position != BLOCK_SIZE)
+      throw Decoding_Error(name());
+   cipher->decrypt(buffer, temp);
+   xor_buf(temp, state, BLOCK_SIZE);
+   send(temp, padder->unpad(temp, BLOCK_SIZE));
+   state = buffer;
+   position = 0;
+   }
+
+/*************************************************
+* Return a CBC mode name                         *
+*************************************************/
+std::string CBC_Decryption::name() const
+   {
+   return (cipher->name() + "/" + mode_name + "/" + padder->name());
+   }
+
+}