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-rw-r--r--src/modes/xts/xts.cpp285
1 files changed, 0 insertions, 285 deletions
diff --git a/src/modes/xts/xts.cpp b/src/modes/xts/xts.cpp
deleted file mode 100644
index 02da5fa5d..000000000
--- a/src/modes/xts/xts.cpp
+++ /dev/null
@@ -1,285 +0,0 @@
-/*
-* XTS Mode
-* (C) 2009,2013 Jack Lloyd
-*
-* Distributed under the terms of the Botan license
-*/
-
-#include <botan/xts.h>
-#include <botan/loadstor.h>
-#include <botan/internal/xor_buf.h>
-#include <botan/internal/rounding.h>
-
-namespace Botan {
-
-namespace {
-
-void poly_double_128(byte out[], const byte in[])
- {
- u64bit X0 = load_le<u64bit>(in, 0);
- u64bit X1 = load_le<u64bit>(in, 1);
-
- const bool carry = (X1 >> 63);
-
- X1 = (X1 << 1) | (X0 >> 63);
- X0 = (X0 << 1);
-
- if(carry)
- X0 ^= 0x87;
-
- store_le(out, X0, X1);
- }
-
-void poly_double_64(byte out[], const byte in[])
- {
- u64bit X = load_le<u64bit>(in, 0);
- const bool carry = (X >> 63);
- X <<= 1;
- if(carry)
- X ^= 0x1B;
- store_le(X, out);
- }
-
-inline void poly_double(byte out[], const byte in[], size_t size)
- {
- if(size == 8)
- poly_double_64(out, in);
- else
- poly_double_128(out, in);
- }
-
-}
-
-XTS_Mode::XTS_Mode(BlockCipher* cipher) : m_cipher(cipher)
- {
- if(m_cipher->block_size() != 8 && m_cipher->block_size() != 16)
- throw std::invalid_argument("Bad cipher for XTS: " + cipher->name());
-
- m_tweak_cipher.reset(m_cipher->clone());
- m_tweak.resize(update_granularity());
- }
-
-void XTS_Mode::clear()
- {
- m_cipher->clear();
- m_tweak_cipher->clear();
- zeroise(m_tweak);
- }
-
-std::string XTS_Mode::name() const
- {
- return cipher().name() + "/XTS";
- }
-
-size_t XTS_Mode::update_granularity() const
- {
- return cipher().parallel_bytes();
- }
-
-size_t XTS_Mode::minimum_final_size() const
- {
- return cipher().block_size() + 1;
- }
-
-Key_Length_Specification XTS_Mode::key_spec() const
- {
- return cipher().key_spec().multiple(2);
- }
-
-size_t XTS_Mode::default_nonce_length() const
- {
- return cipher().block_size();
- }
-
-bool XTS_Mode::valid_nonce_length(size_t n) const
- {
- return cipher().block_size() == n;
- }
-
-void XTS_Mode::key_schedule(const byte key[], size_t length)
- {
- const size_t key_half = length / 2;
-
- if(length % 2 == 1 || !m_cipher->valid_keylength(key_half))
- throw Invalid_Key_Length(name(), length);
-
- m_cipher->set_key(&key[0], key_half);
- m_tweak_cipher->set_key(&key[key_half], key_half);
- }
-
-secure_vector<byte> XTS_Mode::start(const byte nonce[], size_t nonce_len)
- {
- if(!valid_nonce_length(nonce_len))
- throw Invalid_IV_Length(name(), nonce_len);
-
- copy_mem(&m_tweak[0], nonce, nonce_len);
- m_tweak_cipher->encrypt(&m_tweak[0]);
-
- update_tweak(0);
-
- return secure_vector<byte>();
- }
-
-void XTS_Mode::update_tweak(size_t which)
- {
- const size_t BS = m_tweak_cipher->block_size();
-
- if(which > 0)
- poly_double(&m_tweak[0], &m_tweak[(which-1)*BS], BS);
-
- const size_t blocks_in_tweak = update_granularity() / BS;
-
- for(size_t i = 1; i < blocks_in_tweak; ++i)
- poly_double(&m_tweak[i*BS], &m_tweak[(i-1)*BS], BS);
- }
-
-size_t XTS_Encryption::output_length(size_t input_length) const
- {
- return round_up(input_length, cipher().block_size());
- }
-
-void XTS_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, "Input is full blocks");
- size_t blocks = sz / BS;
-
- const size_t blocks_in_tweak = update_granularity() / BS;
-
- while(blocks)
- {
- const size_t to_proc = std::min(blocks, blocks_in_tweak);
- const size_t to_proc_bytes = to_proc * BS;
-
- xor_buf(buf, tweak(), to_proc_bytes);
- cipher().encrypt_n(buf, buf, to_proc);
- xor_buf(buf, tweak(), to_proc_bytes);
-
- buf += to_proc * BS;
- blocks -= to_proc;
-
- update_tweak(to_proc);
- }
- }
-
-void XTS_Encryption::finish(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];
-
- BOTAN_ASSERT(sz >= minimum_final_size(), "Have sufficient final input");
-
- const size_t BS = cipher().block_size();
-
- if(sz % BS == 0)
- {
- update(buffer, offset);
- }
- else
- {
- // steal ciphertext
- const size_t full_blocks = ((sz / BS) - 1) * BS;
- const size_t final_bytes = sz - full_blocks;
- BOTAN_ASSERT(final_bytes > BS && final_bytes < 2*BS, "Left over size in expected range");
-
- secure_vector<byte> last(buf + full_blocks, buf + full_blocks + final_bytes);
- buffer.resize(full_blocks + offset);
- update(buffer, offset);
-
- xor_buf(last, tweak(), BS);
- cipher().encrypt(last);
- xor_buf(last, tweak(), BS);
-
- for(size_t i = 0; i != final_bytes - BS; ++i)
- std::swap(last[i], last[i + BS]);
-
- xor_buf(last, tweak() + BS, BS);
- cipher().encrypt(last);
- xor_buf(last, tweak() + BS, BS);
-
- buffer += last;
- }
- }
-
-size_t XTS_Decryption::output_length(size_t input_length) const
- {
- // might be less
- return input_length;
- }
-
-void XTS_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;
-
- const size_t blocks_in_tweak = update_granularity() / BS;
-
- while(blocks)
- {
- const size_t to_proc = std::min(blocks, blocks_in_tweak);
- const size_t to_proc_bytes = to_proc * BS;
-
- xor_buf(buf, tweak(), to_proc_bytes);
- cipher().decrypt_n(buf, buf, to_proc);
- xor_buf(buf, tweak(), to_proc_bytes);
-
- buf += to_proc * BS;
- blocks -= to_proc;
-
- update_tweak(to_proc);
- }
- }
-
-void XTS_Decryption::finish(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];
-
- BOTAN_ASSERT(sz >= minimum_final_size(), "Have sufficient final input");
-
- const size_t BS = cipher().block_size();
-
- if(sz % BS == 0)
- {
- update(buffer, offset);
- }
- else
- {
- // steal ciphertext
- const size_t full_blocks = ((sz / BS) - 1) * BS;
- const size_t final_bytes = sz - full_blocks;
- BOTAN_ASSERT(final_bytes > BS && final_bytes < 2*BS, "Left over size in expected range");
-
- secure_vector<byte> last(buf + full_blocks, buf + full_blocks + final_bytes);
- buffer.resize(full_blocks + offset);
- update(buffer, offset);
-
- xor_buf(last, tweak() + BS, BS);
- cipher().decrypt(last);
- xor_buf(last, tweak() + BS, BS);
-
- for(size_t i = 0; i != final_bytes - BS; ++i)
- std::swap(last[i], last[i + BS]);
-
- xor_buf(last, tweak(), BS);
- cipher().decrypt(last);
- xor_buf(last, tweak(), BS);
-
- buffer += last;
- }
- }
-
-}
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