1 files changed, 149 insertions, 0 deletions
diff --git a/src/lib/modes/ecb/ecb.cpp b/src/lib/modes/ecb/ecb.cpp
new file mode 100644
index 000000000..f026eb035
--- /dev/null
+++ b/src/lib/modes/ecb/ecb.cpp
@@ -0,0 +1,149 @@
+/*
+* ECB Mode
+* (C) 1999-2009,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/ecb.h>
+#include <botan/loadstor.h>
+#include <botan/internal/xor_buf.h>
+#include <botan/internal/rounding.h>
+
+namespace Botan {
+
+ECB_Mode::ECB_Mode(BlockCipher* cipher, BlockCipherModePaddingMethod* padding) :
+   m_cipher(cipher),
+   m_padding(padding)
+   {
+   if(!m_padding->valid_blocksize(cipher->block_size()))
+      throw std::invalid_argument("Padding " + m_padding->name() +
+                                  " cannot be used with " +
+                                  cipher->name() + "/ECB");
+   }
+
+void ECB_Mode::clear()
+   {
+   m_cipher->clear();
+   }
+
+std::string ECB_Mode::name() const
+   {
+   return cipher().name() + "/ECB/" + padding().name();
+   }
+
+size_t ECB_Mode::update_granularity() const
+   {
+   return cipher().parallel_bytes();
+   }
+
+Key_Length_Specification ECB_Mode::key_spec() const
+   {
+   return cipher().key_spec();
+   }
+
+size_t ECB_Mode::default_nonce_length() const
+   {
+   return 0;
+   }
+
+bool ECB_Mode::valid_nonce_length(size_t n) const
+   {
+   return (n == 0);
+   }
+
+void ECB_Mode::key_schedule(const byte key[], size_t length)
+   {
+   m_cipher->set_key(key, length);
+   }
+
+secure_vector<byte> ECB_Mode::start(const byte[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   return secure_vector<byte>();
+   }
+
+size_t ECB_Encryption::minimum_final_size() const
+   {
+   return 0;
+   }
+
+size_t ECB_Encryption::output_length(size_t input_length) const
+   {
+   return round_up(input_length, cipher().block_size());
+   }
+
+void ECB_Encryption::update(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+   const size_t sz = buffer.size() - offset;
+   byte* buf = &buffer[offset];
+
+   const size_t BS = cipher().block_size();
+
+   BOTAN_ASSERT(sz % BS == 0, "ECB input is full blocks");
+   const size_t blocks = sz / BS;
+
+   cipher().encrypt_n(&buf[0], &buf[0], blocks);
+   }
+
+void ECB_Encryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+   const size_t sz = buffer.size() - offset;
+
+   const size_t BS = cipher().block_size();
+
+   const size_t bytes_in_final_block = sz % BS;
+
+   padding().add_padding(buffer, bytes_in_final_block, BS);
+
+   if(buffer.size() % BS)
+      throw std::runtime_error("Did not pad to full block size in " + name());
+
+   update(buffer, offset);
+   }
+
+size_t ECB_Decryption::output_length(size_t input_length) const
+   {
+   return input_length;
+   }
+
+size_t ECB_Decryption::minimum_final_size() const
+   {
+   return cipher().block_size();
+   }
+
+void ECB_Decryption::update(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+   const size_t sz = buffer.size() - offset;
+   byte* buf = &buffer[offset];
+
+   const size_t BS = cipher().block_size();
+
+   BOTAN_ASSERT(sz % BS == 0, "Input is full blocks");
+   size_t blocks = sz / BS;
+
+   cipher().decrypt_n(&buf[0], &buf[0], blocks);
+   }
+
+void ECB_Decryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+   const size_t sz = buffer.size() - offset;
+
+   const size_t BS = cipher().block_size();
+
+   if(sz == 0 || sz % BS)
+      throw Decoding_Error(name() + ": Ciphertext not a multiple of block size");
+
+   update(buffer, offset);
+
+   const size_t pad_bytes = BS - padding().unpad(&buffer[buffer.size()-BS], BS);
+   buffer.resize(buffer.size() - pad_bytes); // remove padding
+   }
+
+}