Move lib into src

38 files changed, 3833 insertions, 0 deletions

diff --git a/src/lib/modes/aead/aead.cpp b/src/lib/modes/aead/aead.cpp
new file mode 100644
index 000000000..da860c26a
--- /dev/null
+++ b/src/lib/modes/aead/aead.cpp
@@ -0,0 +1,122 @@
+/*
+* Interface for AEAD modes
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/aead.h>
+#include <botan/libstate.h>
+
+#if defined(BOTAN_HAS_AEAD_CCM)
+  #include <botan/ccm.h>
+#endif
+
+#if defined(BOTAN_HAS_AEAD_EAX)
+  #include <botan/eax.h>
+#endif
+
+#if defined(BOTAN_HAS_AEAD_GCM)
+  #include <botan/gcm.h>
+#endif
+
+#if defined(BOTAN_HAS_AEAD_SIV)
+  #include <botan/siv.h>
+#endif
+
+#if defined(BOTAN_HAS_AEAD_OCB)
+  #include <botan/ocb.h>
+#endif
+
+namespace Botan {
+
+AEAD_Mode* get_aead(const std::string& algo_spec, Cipher_Dir direction)
+   {
+   Algorithm_Factory& af = global_state().algorithm_factory();
+
+   const std::vector<std::string> algo_parts = split_on(algo_spec, '/');
+   if(algo_parts.empty())
+      throw Invalid_Algorithm_Name(algo_spec);
+
+   if(algo_parts.size() < 2)
+      return nullptr;
+
+   const std::string cipher_name = algo_parts[0];
+   const BlockCipher* cipher = af.prototype_block_cipher(cipher_name);
+   if(!cipher)
+      return nullptr;
+
+   const std::vector<std::string> mode_info = parse_algorithm_name(algo_parts[1]);
+
+   if(mode_info.empty())
+      return nullptr;
+
+   const std::string mode_name = mode_info[0];
+
+   const size_t tag_size = (mode_info.size() > 1) ? to_u32bit(mode_info[1]) : cipher->block_size();
+
+#if defined(BOTAN_HAS_AEAD_CCM)
+   if(mode_name == "CCM-8")
+      {
+      if(direction == ENCRYPTION)
+         return new CCM_Encryption(cipher->clone(), 8, 3);
+      else
+         return new CCM_Decryption(cipher->clone(), 8, 3);
+      }
+
+   if(mode_name == "CCM" || mode_name == "CCM-8")
+      {
+      const size_t L = (mode_info.size() > 2) ? to_u32bit(mode_info[2]) : 3;
+
+      if(direction == ENCRYPTION)
+         return new CCM_Encryption(cipher->clone(), tag_size, L);
+      else
+         return new CCM_Decryption(cipher->clone(), tag_size, L);
+      }
+#endif
+
+#if defined(BOTAN_HAS_AEAD_EAX)
+   if(mode_name == "EAX")
+      {
+      if(direction == ENCRYPTION)
+         return new EAX_Encryption(cipher->clone(), tag_size);
+      else
+         return new EAX_Decryption(cipher->clone(), tag_size);
+      }
+#endif
+
+#if defined(BOTAN_HAS_AEAD_SIV)
+   if(mode_name == "SIV")
+      {
+      BOTAN_ASSERT(tag_size == 16, "Valid tag size for SIV");
+      if(direction == ENCRYPTION)
+         return new SIV_Encryption(cipher->clone());
+      else
+         return new SIV_Decryption(cipher->clone());
+      }
+#endif
+
+#if defined(BOTAN_HAS_AEAD_GCM)
+   if(mode_name == "GCM")
+      {
+      if(direction == ENCRYPTION)
+         return new GCM_Encryption(cipher->clone(), tag_size);
+      else
+         return new GCM_Decryption(cipher->clone(), tag_size);
+      }
+#endif
+
+#if defined(BOTAN_HAS_AEAD_OCB)
+   if(mode_name == "OCB")
+      {
+      if(direction == ENCRYPTION)
+         return new OCB_Encryption(cipher->clone(), tag_size);
+      else
+         return new OCB_Decryption(cipher->clone(), tag_size);
+      }
+#endif
+
+   return nullptr;
+   }
+
+}
diff --git a/src/lib/modes/aead/aead.h b/src/lib/modes/aead/aead.h
new file mode 100644
index 000000000..8df98fcad
--- /dev/null
+++ b/src/lib/modes/aead/aead.h
@@ -0,0 +1,66 @@
+/*
+* Interface for AEAD modes
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_AEAD_MODE_H__
+#define BOTAN_AEAD_MODE_H__
+
+#include <botan/cipher_mode.h>
+
+namespace Botan {
+
+/**
+* Interface for AEAD (Authenticated Encryption with Associated Data)
+* modes. These modes provide both encryption and message
+* authentication, and can authenticate additional per-message data
+* which is not included in the ciphertext (for instance a sequence
+* number).
+*/
+class BOTAN_DLL AEAD_Mode : public Cipher_Mode
+   {
+   public:
+      bool authenticated() const override { return true; }
+
+      /**
+      * Set associated data that is not included in the ciphertext but
+      * that should be authenticated. Must be called after set_key
+      * and before finish.
+      *
+      * Unless reset by another call, the associated data is kept
+      * between messages. Thus, if the AD does not change, calling
+      * once (after set_key) is the optimum.
+      *
+      * @param ad the associated data
+      * @param ad_len length of add in bytes
+      */
+      virtual void set_associated_data(const byte ad[], size_t ad_len) = 0;
+
+      template<typename Alloc>
+      void set_associated_data_vec(const std::vector<byte, Alloc>& ad)
+         {
+         set_associated_data(&ad[0], ad.size());
+         }
+
+      /**
+      * Default AEAD nonce size (a commonly supported value among AEAD
+      * modes, and large enough that random collisions are unlikely).
+      */
+      size_t default_nonce_length() const override { return 12; }
+
+      /**
+      * Return the size of the authentication tag used (in bytes)
+      */
+      virtual size_t tag_size() const = 0;
+   };
+
+/**
+* Get an AEAD mode by name (eg "AES-128/GCM" or "Serpent/EAX")
+*/
+BOTAN_DLL AEAD_Mode* get_aead(const std::string& name, Cipher_Dir direction);
+
+}
+
+#endif
diff --git a/src/lib/modes/aead/ccm/ccm.cpp b/src/lib/modes/aead/ccm/ccm.cpp
new file mode 100644
index 000000000..50fc38738
--- /dev/null
+++ b/src/lib/modes/aead/ccm/ccm.cpp
@@ -0,0 +1,266 @@
+/*
+* CCM Mode Encryption
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/ccm.h>
+#include <botan/parsing.h>
+#include <botan/internal/xor_buf.h>
+#include <algorithm>
+
+namespace Botan {
+
+/*
+* CCM_Mode Constructor
+*/
+CCM_Mode::CCM_Mode(BlockCipher* cipher, size_t tag_size, size_t L) :
+   m_tag_size(tag_size),
+   m_L(L),
+   m_cipher(cipher)
+   {
+   if(m_cipher->block_size() != BS)
+      throw std::invalid_argument(m_cipher->name() + " cannot be used with CCM mode");
+
+   if(L < 2 || L > 8)
+      throw std::invalid_argument("Invalid CCM L value " + std::to_string(L));
+
+   if(tag_size < 4 || tag_size > 16 || tag_size % 2 != 0)
+      throw std::invalid_argument("invalid CCM tag length " + std::to_string(tag_size));
+   }
+
+void CCM_Mode::clear()
+   {
+   m_cipher.reset();
+   m_msg_buf.clear();
+   m_ad_buf.clear();
+   }
+
+std::string CCM_Mode::name() const
+   {
+   return (m_cipher->name() + "/CCM(" + std::to_string(tag_size()) + "," + std::to_string(L())) + ")";
+   }
+
+bool CCM_Mode::valid_nonce_length(size_t n) const
+   {
+   return (n == (15-L()));
+   }
+
+size_t CCM_Mode::default_nonce_length() const
+   {
+   return (15-L());
+   }
+
+size_t CCM_Mode::update_granularity() const
+   {
+   /*
+   This value does not particularly matter as regardless CCM_Mode::update
+   buffers all input, so in theory this could be 1. However as for instance
+   Transformation_Filter creates update_granularity() byte buffers, use a
+   somewhat large size to avoid bouncing on a tiny buffer.
+   */
+   return m_cipher->parallel_bytes();
+   }
+
+Key_Length_Specification CCM_Mode::key_spec() const
+   {
+   return m_cipher->key_spec();
+   }
+
+void CCM_Mode::key_schedule(const byte key[], size_t length)
+   {
+   m_cipher->set_key(key, length);
+   }
+
+void CCM_Mode::set_associated_data(const byte ad[], size_t length)
+   {
+   m_ad_buf.clear();
+
+   if(length)
+      {
+      // FIXME: support larger AD using length encoding rules
+      BOTAN_ASSERT(length < (0xFFFF - 0xFF), "Supported CCM AD length");
+
+      m_ad_buf.push_back(get_byte<u16bit>(0, length));
+      m_ad_buf.push_back(get_byte<u16bit>(1, length));
+      m_ad_buf += std::make_pair(ad, length);
+      while(m_ad_buf.size() % BS)
+         m_ad_buf.push_back(0); // pad with zeros to full block size
+      }
+   }
+
+secure_vector<byte> CCM_Mode::start(const byte nonce[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   m_nonce.assign(nonce, nonce + nonce_len);
+   m_msg_buf.clear();
+
+   return secure_vector<byte>();
+   }
+
+void CCM_Mode::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];
+
+   m_msg_buf.insert(m_msg_buf.end(), buf, buf + sz);
+   buffer.resize(offset); // truncate msg
+   }
+
+void CCM_Mode::encode_length(size_t len, byte out[])
+   {
+   const size_t len_bytes = L();
+
+   BOTAN_ASSERT(len_bytes < sizeof(size_t), "Length field fits");
+
+   for(size_t i = 0; i != len_bytes; ++i)
+      out[i] = get_byte(sizeof(size_t)-i, len);
+
+   BOTAN_ASSERT((len >> (len_bytes*8)) == 0, "Message length fits in field");
+   }
+
+void CCM_Mode::inc(secure_vector<byte>& C)
+   {
+   for(size_t i = 0; i != C.size(); ++i)
+      if(++C[C.size()-i-1])
+         break;
+   }
+
+secure_vector<byte> CCM_Mode::format_b0(size_t sz)
+   {
+   secure_vector<byte> B0(BS);
+
+   const byte b_flags = (m_ad_buf.size() ? 64 : 0) + (((tag_size()/2)-1) << 3) + (L()-1);
+
+   B0[0] = b_flags;
+   copy_mem(&B0[1], &m_nonce[0], m_nonce.size());
+   encode_length(sz, &B0[m_nonce.size()+1]);
+
+   return B0;
+   }
+
+secure_vector<byte> CCM_Mode::format_c0()
+   {
+   secure_vector<byte> C(BS);
+
+   const byte a_flags = L()-1;
+
+   C[0] = a_flags;
+   copy_mem(&C[1], &m_nonce[0], m_nonce.size());
+
+   return C;
+   }
+
+void CCM_Encryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+
+   buffer.insert(buffer.begin() + offset, msg_buf().begin(), msg_buf().end());
+
+   const size_t sz = buffer.size() - offset;
+   byte* buf = &buffer[offset];
+
+   const secure_vector<byte>& ad = ad_buf();
+   BOTAN_ASSERT(ad.size() % BS == 0, "AD is block size multiple");
+
+   const BlockCipher& E = cipher();
+
+   secure_vector<byte> T(BS);
+   E.encrypt(format_b0(sz), T);
+
+   for(size_t i = 0; i != ad.size(); i += BS)
+      {
+      xor_buf(&T[0], &ad[i], BS);
+      E.encrypt(T);
+      }
+
+   secure_vector<byte> C = format_c0();
+   secure_vector<byte> S0(BS);
+   E.encrypt(C, S0);
+   inc(C);
+
+   secure_vector<byte> X(BS);
+
+   const byte* buf_end = &buf[sz];
+
+   while(buf != buf_end)
+      {
+      const size_t to_proc = std::min<size_t>(BS, buf_end - buf);
+
+      xor_buf(&T[0], buf, to_proc);
+      E.encrypt(T);
+
+      E.encrypt(C, X);
+      xor_buf(buf, &X[0], to_proc);
+      inc(C);
+
+      buf += to_proc;
+      }
+
+   T ^= S0;
+
+   buffer += std::make_pair(&T[0], tag_size());
+   }
+
+void CCM_Decryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+
+   buffer.insert(buffer.begin() + offset, msg_buf().begin(), msg_buf().end());
+
+   const size_t sz = buffer.size() - offset;
+   byte* buf = &buffer[offset];
+
+   BOTAN_ASSERT(sz >= tag_size(), "We have the tag");
+
+   const secure_vector<byte>& ad = ad_buf();
+   BOTAN_ASSERT(ad.size() % BS == 0, "AD is block size multiple");
+
+   const BlockCipher& E = cipher();
+
+   secure_vector<byte> T(BS);
+   E.encrypt(format_b0(sz - tag_size()), T);
+
+   for(size_t i = 0; i != ad.size(); i += BS)
+      {
+      xor_buf(&T[0], &ad[i], BS);
+      E.encrypt(T);
+      }
+
+   secure_vector<byte> C = format_c0();
+
+   secure_vector<byte> S0(BS);
+   E.encrypt(C, S0);
+   inc(C);
+
+   secure_vector<byte> X(BS);
+
+   const byte* buf_end = &buf[sz - tag_size()];
+
+   while(buf != buf_end)
+      {
+      const size_t to_proc = std::min<size_t>(BS, buf_end - buf);
+
+      E.encrypt(C, X);
+      xor_buf(buf, &X[0], to_proc);
+      inc(C);
+
+      xor_buf(&T[0], buf, to_proc);
+      E.encrypt(T);
+
+      buf += to_proc;
+      }
+
+   T ^= S0;
+
+   if(!same_mem(&T[0], buf_end, tag_size()))
+      throw Integrity_Failure("CCM tag check failed");
+
+   buffer.resize(buffer.size() - tag_size());
+   }
+
+}
diff --git a/src/lib/modes/aead/ccm/ccm.h b/src/lib/modes/aead/ccm/ccm.h
new file mode 100644
index 000000000..87dd5805c
--- /dev/null
+++ b/src/lib/modes/aead/ccm/ccm.h
@@ -0,0 +1,128 @@
+/*
+* CCM Mode
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_AEAD_CCM_H__
+#define BOTAN_AEAD_CCM_H__
+
+#include <botan/aead.h>
+#include <botan/block_cipher.h>
+#include <botan/stream_cipher.h>
+#include <botan/mac.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* Base class for CCM encryption and decryption
+* @see RFC 3610
+*/
+class BOTAN_DLL CCM_Mode : public AEAD_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void set_associated_data(const byte ad[], size_t ad_len) override;
+
+      std::string name() const override;
+
+      size_t update_granularity() const;
+
+      Key_Length_Specification key_spec() const override;
+
+      bool valid_nonce_length(size_t) const override;
+
+      size_t default_nonce_length() const override;
+
+      void clear();
+
+      size_t tag_size() const { return m_tag_size; }
+
+   protected:
+      const size_t BS = 16; // intrinsic to CCM definition
+
+      CCM_Mode(BlockCipher* cipher, size_t tag_size, size_t L);
+
+      size_t L() const { return m_L; }
+
+      const BlockCipher& cipher() const { return *m_cipher; }
+
+      void encode_length(size_t len, byte out[]);
+
+      void inc(secure_vector<byte>& C);
+
+      const secure_vector<byte>& ad_buf() const { return m_ad_buf; }
+
+      secure_vector<byte>& msg_buf() { return m_msg_buf; }
+
+      secure_vector<byte> format_b0(size_t msg_size);
+      secure_vector<byte> format_c0();
+   private:
+      void key_schedule(const byte key[], size_t length) override;
+
+      const size_t m_tag_size;
+      const size_t m_L;
+
+      std::unique_ptr<BlockCipher> m_cipher;
+      secure_vector<byte> m_nonce, m_msg_buf, m_ad_buf;
+   };
+
+/**
+* CCM Encryption
+*/
+class BOTAN_DLL CCM_Encryption : public CCM_Mode
+   {
+   public:
+      /**
+      * @param cipher a 128-bit block cipher
+      * @param tag_size is how big the auth tag will be (even values
+      *                 between 4 and 16 are accepted)
+      * @param L length of L parameter. The total message length
+      *           must be less than 2**L bytes, and the nonce is 15-L bytes.
+      */
+      CCM_Encryption(BlockCipher* cipher, size_t tag_size = 16, size_t L = 3) :
+         CCM_Mode(cipher, tag_size, L) {}
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override
+         { return input_length + tag_size(); }
+
+      size_t minimum_final_size() const override { return 0; }
+   };
+
+/**
+* CCM Decryption
+*/
+class BOTAN_DLL CCM_Decryption : public CCM_Mode
+   {
+   public:
+      /**
+      * @param cipher a 128-bit block cipher
+      * @param tag_size is how big the auth tag will be (even values
+      *                 between 4 and 16 are accepted)
+      * @param L length of L parameter. The total message length
+      *           must be less than 2**L bytes, and the nonce is 15-L bytes.
+      */
+      CCM_Decryption(BlockCipher* cipher, size_t tag_size = 16, size_t L = 3) :
+         CCM_Mode(cipher, tag_size, L) {}
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override
+         {
+         BOTAN_ASSERT(input_length > tag_size(), "Sufficient input");
+         return input_length - tag_size();
+         }
+
+      size_t minimum_final_size() const override { return tag_size(); }
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/aead/ccm/info.txt b/src/lib/modes/aead/ccm/info.txt
new file mode 100644
index 000000000..ee8373caf
--- /dev/null
+++ b/src/lib/modes/aead/ccm/info.txt
@@ -0,0 +1 @@
+define AEAD_CCM 20131128
diff --git a/src/lib/modes/aead/eax/eax.cpp b/src/lib/modes/aead/eax/eax.cpp
new file mode 100644
index 000000000..249bf5f7e
--- /dev/null
+++ b/src/lib/modes/aead/eax/eax.cpp
@@ -0,0 +1,170 @@
+/*
+* EAX Mode Encryption
+* (C) 1999-2007 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/eax.h>
+#include <botan/cmac.h>
+#include <botan/ctr.h>
+#include <botan/parsing.h>
+#include <botan/internal/xor_buf.h>
+#include <algorithm>
+
+namespace Botan {
+
+namespace {
+
+/*
+* EAX MAC-based PRF
+*/
+secure_vector<byte> eax_prf(byte tag, size_t block_size,
+                           MessageAuthenticationCode& mac,
+                           const byte in[], size_t length)
+   {
+   for(size_t i = 0; i != block_size - 1; ++i)
+      mac.update(0);
+   mac.update(tag);
+   mac.update(in, length);
+   return mac.final();
+   }
+
+}
+
+/*
+* EAX_Mode Constructor
+*/
+EAX_Mode::EAX_Mode(BlockCipher* cipher, size_t tag_size) :
+   m_tag_size(tag_size ? tag_size : cipher->block_size()),
+   m_cipher(cipher),
+   m_ctr(new CTR_BE(m_cipher->clone())),
+   m_cmac(new CMAC(m_cipher->clone()))
+   {
+   if(m_tag_size < 8 || m_tag_size > m_cmac->output_length())
+      throw Invalid_Argument(name() + ": Bad tag size " + std::to_string(tag_size));
+   }
+
+void EAX_Mode::clear()
+   {
+   m_cipher.reset();
+   m_ctr.reset();
+   m_cmac.reset();
+   zeroise(m_ad_mac);
+   zeroise(m_nonce_mac);
+   }
+
+std::string EAX_Mode::name() const
+   {
+   return (m_cipher->name() + "/EAX");
+   }
+
+size_t EAX_Mode::update_granularity() const
+   {
+   return 8 * m_cipher->parallel_bytes();
+   }
+
+Key_Length_Specification EAX_Mode::key_spec() const
+   {
+   return m_cipher->key_spec();
+   }
+
+/*
+* Set the EAX key
+*/
+void EAX_Mode::key_schedule(const byte key[], size_t length)
+   {
+   /*
+   * These could share the key schedule, which is one nice part of EAX,
+   * but it's much easier to ignore that here...
+   */
+   m_ctr->set_key(key, length);
+   m_cmac->set_key(key, length);
+
+   m_ad_mac = eax_prf(1, block_size(), *m_cmac, nullptr, 0);
+   }
+
+/*
+* Set the EAX associated data
+*/
+void EAX_Mode::set_associated_data(const byte ad[], size_t length)
+   {
+   m_ad_mac = eax_prf(1, block_size(), *m_cmac, ad, length);
+   }
+
+secure_vector<byte> EAX_Mode::start(const byte nonce[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   m_nonce_mac = eax_prf(0, block_size(), *m_cmac, nonce, nonce_len);
+
+   m_ctr->set_iv(&m_nonce_mac[0], m_nonce_mac.size());
+
+   for(size_t i = 0; i != block_size() - 1; ++i)
+      m_cmac->update(0);
+   m_cmac->update(2);
+
+   return secure_vector<byte>();
+   }
+
+void EAX_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];
+
+   m_ctr->cipher(buf, buf, sz);
+   m_cmac->update(buf, sz);
+   }
+
+void EAX_Encryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   update(buffer, offset);
+
+   secure_vector<byte> data_mac = m_cmac->final();
+   xor_buf(data_mac, m_nonce_mac, data_mac.size());
+   xor_buf(data_mac, m_ad_mac, data_mac.size());
+
+   buffer += std::make_pair(&data_mac[0], tag_size());
+   }
+
+void EAX_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];
+
+   m_cmac->update(buf, sz);
+   m_ctr->cipher(buf, buf, sz);
+   }
+
+void EAX_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 >= tag_size(), "Have the tag as part of final input");
+
+   const size_t remaining = sz - tag_size();
+
+   if(remaining)
+      {
+      m_cmac->update(buf, remaining);
+      m_ctr->cipher(buf, buf, remaining);
+      }
+
+   const byte* included_tag = &buf[remaining];
+
+   secure_vector<byte> mac = m_cmac->final();
+   mac ^= m_nonce_mac;
+   mac ^= m_ad_mac;
+
+   if(!same_mem(&mac[0], included_tag, tag_size()))
+      throw Integrity_Failure("EAX tag check failed");
+
+   buffer.resize(offset + remaining);
+   }
+
+}
diff --git a/src/lib/modes/aead/eax/eax.h b/src/lib/modes/aead/eax/eax.h
new file mode 100644
index 000000000..224fb5298
--- /dev/null
+++ b/src/lib/modes/aead/eax/eax.h
@@ -0,0 +1,114 @@
+/*
+* EAX Mode
+* (C) 1999-2007,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_AEAD_EAX_H__
+#define BOTAN_AEAD_EAX_H__
+
+#include <botan/aead.h>
+#include <botan/block_cipher.h>
+#include <botan/stream_cipher.h>
+#include <botan/mac.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* EAX base class
+*/
+class BOTAN_DLL EAX_Mode : public AEAD_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      void set_associated_data(const byte ad[], size_t ad_len) override;
+
+      std::string name() const override;
+
+      size_t update_granularity() const;
+
+      Key_Length_Specification key_spec() const override;
+
+      // EAX supports arbitrary nonce lengths
+      bool valid_nonce_length(size_t) const override { return true; }
+
+      size_t tag_size() const { return m_tag_size; }
+
+      void clear();
+   protected:
+      void key_schedule(const byte key[], size_t length) override;
+
+      /**
+      * @param cipher the cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      EAX_Mode(BlockCipher* cipher, size_t tag_size);
+
+      size_t block_size() const { return m_cipher->block_size(); }
+
+      size_t m_tag_size;
+
+      std::unique_ptr<BlockCipher> m_cipher;
+      std::unique_ptr<StreamCipher> m_ctr;
+      std::unique_ptr<MessageAuthenticationCode> m_cmac;
+
+      secure_vector<byte> m_ad_mac;
+
+      secure_vector<byte> m_nonce_mac;
+   };
+
+/**
+* EAX Encryption
+*/
+class BOTAN_DLL EAX_Encryption : public EAX_Mode
+   {
+   public:
+      /**
+      * @param cipher a 128-bit block cipher
+      * @param tag_size is how big the auth tag will be
+      */
+      EAX_Encryption(BlockCipher* cipher, size_t tag_size = 0) :
+         EAX_Mode(cipher, tag_size) {}
+
+      size_t output_length(size_t input_length) const override
+         { return input_length + tag_size(); }
+
+      size_t minimum_final_size() const override { return 0; }
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   };
+
+/**
+* EAX Decryption
+*/
+class BOTAN_DLL EAX_Decryption : public EAX_Mode
+   {
+   public:
+      /**
+      * @param cipher a 128-bit block cipher
+      * @param tag_size is how big the auth tag will be
+      */
+      EAX_Decryption(BlockCipher* cipher, size_t tag_size = 0) :
+         EAX_Mode(cipher, tag_size) {}
+
+      size_t output_length(size_t input_length) const override
+         {
+         BOTAN_ASSERT(input_length > tag_size(), "Sufficient input");
+         return input_length - tag_size();
+         }
+
+      size_t minimum_final_size() const override { return tag_size(); }
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/aead/eax/info.txt b/src/lib/modes/aead/eax/info.txt
new file mode 100644
index 000000000..75775fa16
--- /dev/null
+++ b/src/lib/modes/aead/eax/info.txt
@@ -0,0 +1,7 @@
+define AEAD_EAX 20131128
+
+<requires>
+block
+cmac
+ctr
+</requires>
diff --git a/src/lib/modes/aead/gcm/clmul/clmul.cpp b/src/lib/modes/aead/gcm/clmul/clmul.cpp
new file mode 100644
index 000000000..cc6d581e3
--- /dev/null
+++ b/src/lib/modes/aead/gcm/clmul/clmul.cpp
@@ -0,0 +1,76 @@
+/*
+* CLMUL hook
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/internal/clmul.h>
+#include <immintrin.h>
+
+namespace Botan {
+
+void gcm_multiply_clmul(byte x[16], const byte H[16])
+   {
+   /*
+   * Algorithms 1 and 5 from Intel's CLMUL guide
+   */
+   const __m128i BSWAP_MASK = _mm_set_epi8(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15);
+
+   __m128i a = _mm_loadu_si128(reinterpret_cast<const __m128i*>(&x[0]));
+   __m128i b = _mm_loadu_si128(reinterpret_cast<const __m128i*>(&H[0]));
+
+   a = _mm_shuffle_epi8(a, BSWAP_MASK);
+   b = _mm_shuffle_epi8(b, BSWAP_MASK);
+
+   __m128i T0, T1, T2, T3, T4, T5;
+
+   T0 = _mm_clmulepi64_si128(a, b, 0x00);
+   T1 = _mm_clmulepi64_si128(a, b, 0x01);
+   T2 = _mm_clmulepi64_si128(a, b, 0x10);
+   T3 = _mm_clmulepi64_si128(a, b, 0x11);
+
+   T1 = _mm_xor_si128(T1, T2);
+   T2 = _mm_slli_si128(T1, 8);
+   T1 = _mm_srli_si128(T1, 8);
+   T0 = _mm_xor_si128(T0, T2);
+   T3 = _mm_xor_si128(T3, T1);
+
+   T4 = _mm_srli_epi32(T0, 31);
+   T0 = _mm_slli_epi32(T0, 1);
+
+   T5 = _mm_srli_epi32(T3, 31);
+   T3 = _mm_slli_epi32(T3, 1);
+
+   T2 = _mm_srli_si128(T4, 12);
+   T5 = _mm_slli_si128(T5, 4);
+   T4 = _mm_slli_si128(T4, 4);
+   T0 = _mm_or_si128(T0, T4);
+   T3 = _mm_or_si128(T3, T5);
+   T3 = _mm_or_si128(T3, T2);
+
+   T4 = _mm_slli_epi32(T0, 31);
+   T5 = _mm_slli_epi32(T0, 30);
+   T2 = _mm_slli_epi32(T0, 25);
+
+   T4 = _mm_xor_si128(T4, T5);
+   T4 = _mm_xor_si128(T4, T2);
+   T5 = _mm_srli_si128(T4, 4);
+   T3 = _mm_xor_si128(T3, T5);
+   T4 = _mm_slli_si128(T4, 12);
+   T0 = _mm_xor_si128(T0, T4);
+   T3 = _mm_xor_si128(T3, T0);
+
+   T4 = _mm_srli_epi32(T0, 1);
+   T1 = _mm_srli_epi32(T0, 2);
+   T2 = _mm_srli_epi32(T0, 7);
+   T3 = _mm_xor_si128(T3, T1);
+   T3 = _mm_xor_si128(T3, T2);
+   T3 = _mm_xor_si128(T3, T4);
+
+   T3 = _mm_shuffle_epi8(T3, BSWAP_MASK);
+
+   _mm_storeu_si128(reinterpret_cast<__m128i*>(&x[0]), T3);
+   }
+
+}
diff --git a/src/lib/modes/aead/gcm/clmul/clmul.h b/src/lib/modes/aead/gcm/clmul/clmul.h
new file mode 100644
index 000000000..ba197f2f7
--- /dev/null
+++ b/src/lib/modes/aead/gcm/clmul/clmul.h
@@ -0,0 +1,14 @@
+/*
+* CLMUL hook
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/types.h>
+
+namespace Botan {
+
+void gcm_multiply_clmul(byte x[16], const byte H[16]);
+
+}
diff --git a/src/lib/modes/aead/gcm/clmul/info.txt b/src/lib/modes/aead/gcm/clmul/info.txt
new file mode 100644
index 000000000..8a21b6ac2
--- /dev/null
+++ b/src/lib/modes/aead/gcm/clmul/info.txt
@@ -0,0 +1,8 @@
+
+define GCM_CLMUL 20131227
+
+need_isa clmul,ssse3
+
+<header:internal>
+clmul.h
+</header:internal>
diff --git a/src/lib/modes/aead/gcm/gcm.cpp b/src/lib/modes/aead/gcm/gcm.cpp
new file mode 100644
index 000000000..b39e6ac92
--- /dev/null
+++ b/src/lib/modes/aead/gcm/gcm.cpp
@@ -0,0 +1,290 @@
+/*
+* GCM Mode Encryption
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/gcm.h>
+#include <botan/ctr.h>
+#include <botan/internal/xor_buf.h>
+#include <botan/loadstor.h>
+
+#if defined(BOTAN_HAS_GCM_CLMUL)
+  #include <botan/internal/clmul.h>
+  #include <botan/cpuid.h>
+#endif
+
+namespace Botan {
+
+void GHASH::gcm_multiply(secure_vector<byte>& x) const
+   {
+#if defined(BOTAN_HAS_GCM_CLMUL)
+   if(CPUID::has_clmul())
+      return gcm_multiply_clmul(&x[0], &m_H[0]);
+#endif
+
+   static const u64bit R = 0xE100000000000000;
+
+   u64bit H[2] = {
+      load_be<u64bit>(&m_H[0], 0),
+      load_be<u64bit>(&m_H[0], 1)
+   };
+
+   u64bit Z[2] = { 0, 0 };
+
+   // SSE2 might be useful here
+
+   for(size_t i = 0; i != 2; ++i)
+      {
+      const u64bit X = load_be<u64bit>(&x[0], i);
+
+      for(size_t j = 0; j != 64; ++j)
+         {
+         if((X >> (63-j)) & 1)
+            {
+            Z[0] ^= H[0];
+            Z[1] ^= H[1];
+            }
+
+         const u64bit r = (H[1] & 1) ? R : 0;
+
+         H[1] = (H[0] << 63) | (H[1] >> 1);
+         H[0] = (H[0] >> 1) ^ r;
+         }
+      }
+
+   store_be<u64bit>(&x[0], Z[0], Z[1]);
+   }
+
+void GHASH::ghash_update(secure_vector<byte>& ghash,
+                         const byte input[], size_t length)
+   {
+   const size_t BS = 16;
+
+   /*
+   This assumes if less than block size input then we're just on the
+   final block and should pad with zeros
+   */
+   while(length)
+      {
+      const size_t to_proc = std::min(length, BS);
+
+      xor_buf(&ghash[0], &input[0], to_proc);
+
+      gcm_multiply(ghash);
+
+      input += to_proc;
+      length -= to_proc;
+      }
+   }
+
+void GHASH::key_schedule(const byte key[], size_t length)
+   {
+   m_H.assign(key, key+length);
+   m_H_ad.resize(16);
+   m_ad_len = 0;
+   m_text_len = 0;
+   }
+
+void GHASH::start(const byte nonce[], size_t len)
+   {
+   m_nonce.assign(nonce, nonce + len);
+   m_ghash = m_H_ad;
+   }
+
+void GHASH::set_associated_data(const byte input[], size_t length)
+   {
+   zeroise(m_H_ad);
+
+   ghash_update(m_H_ad, input, length);
+   m_ad_len = length;
+   }
+
+void GHASH::update(const byte input[], size_t length)
+   {
+   BOTAN_ASSERT(m_ghash.size() == 16, "Key was set");
+
+   m_text_len += length;
+
+   ghash_update(m_ghash, input, length);
+   }
+
+void GHASH::add_final_block(secure_vector<byte>& hash,
+                            size_t ad_len, size_t text_len)
+   {
+   secure_vector<byte> final_block(16);
+   store_be<u64bit>(&final_block[0], 8*ad_len, 8*text_len);
+   ghash_update(hash, &final_block[0], final_block.size());
+   }
+
+secure_vector<byte> GHASH::final()
+   {
+   add_final_block(m_ghash, m_ad_len, m_text_len);
+
+   secure_vector<byte> mac;
+   mac.swap(m_ghash);
+
+   mac ^= m_nonce;
+   m_text_len = 0;
+   return mac;
+   }
+
+secure_vector<byte> GHASH::nonce_hash(const byte nonce[], size_t nonce_len)
+   {
+   BOTAN_ASSERT(m_ghash.size() == 0, "nonce_hash called during wrong time");
+   secure_vector<byte> y0(16);
+
+   ghash_update(y0, nonce, nonce_len);
+   add_final_block(y0, 0, nonce_len);
+
+   return y0;
+   }
+
+void GHASH::clear()
+   {
+   zeroise(m_H);
+   zeroise(m_H_ad);
+   m_ghash.clear();
+   m_text_len = m_ad_len = 0;
+   }
+
+/*
+* GCM_Mode Constructor
+*/
+GCM_Mode::GCM_Mode(BlockCipher* cipher, size_t tag_size) :
+   m_tag_size(tag_size),
+   m_cipher_name(cipher->name())
+   {
+   if(cipher->block_size() != BS)
+      throw std::invalid_argument("GCM requires a 128 bit cipher so cannot be used with " +
+                                  cipher->name());
+
+   m_ghash.reset(new GHASH);
+
+   m_ctr.reset(new CTR_BE(cipher)); // CTR_BE takes ownership of cipher
+
+   if(m_tag_size != 8 && m_tag_size != 16)
+      throw Invalid_Argument(name() + ": Bad tag size " + std::to_string(m_tag_size));
+   }
+
+void GCM_Mode::clear()
+   {
+   m_ctr->clear();
+   m_ghash->clear();
+   }
+
+std::string GCM_Mode::name() const
+   {
+   return (m_cipher_name + "/GCM");
+   }
+
+size_t GCM_Mode::update_granularity() const
+   {
+   return 4096; // CTR-BE's internal block size
+   }
+
+Key_Length_Specification GCM_Mode::key_spec() const
+   {
+   return m_ctr->key_spec();
+   }
+
+void GCM_Mode::key_schedule(const byte key[], size_t keylen)
+   {
+   m_ctr->set_key(key, keylen);
+
+   const std::vector<byte> zeros(BS);
+   m_ctr->set_iv(&zeros[0], zeros.size());
+
+   secure_vector<byte> H(BS);
+   m_ctr->encipher(H);
+   m_ghash->set_key(H);
+   }
+
+void GCM_Mode::set_associated_data(const byte ad[], size_t ad_len)
+   {
+   m_ghash->set_associated_data(ad, ad_len);
+   }
+
+secure_vector<byte> GCM_Mode::start(const byte nonce[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   secure_vector<byte> y0(BS);
+
+   if(nonce_len == 12)
+      {
+      copy_mem(&y0[0], nonce, nonce_len);
+      y0[15] = 1;
+      }
+   else
+      {
+      y0 = m_ghash->nonce_hash(nonce, nonce_len);
+      }
+
+   m_ctr->set_iv(&y0[0], y0.size());
+
+   secure_vector<byte> m_enc_y0(BS);
+   m_ctr->encipher(m_enc_y0);
+
+   m_ghash->start(&m_enc_y0[0], m_enc_y0.size());
+
+   return secure_vector<byte>();
+   }
+
+void GCM_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];
+
+   m_ctr->cipher(buf, buf, sz);
+   m_ghash->update(buf, sz);
+   }
+
+void GCM_Encryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   update(buffer, offset);
+   auto mac = m_ghash->final();
+   buffer += std::make_pair(&mac[0], tag_size());
+   }
+
+void GCM_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];
+
+   m_ghash->update(buf, sz);
+   m_ctr->cipher(buf, buf, sz);
+   }
+
+void GCM_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 >= tag_size(), "Have the tag as part of final input");
+
+   const size_t remaining = sz - tag_size();
+
+   // handle any final input before the tag
+   if(remaining)
+      {
+      m_ghash->update(buf, remaining);
+      m_ctr->cipher(buf, buf, remaining);
+      }
+
+   auto mac = m_ghash->final();
+
+   const byte* included_tag = &buffer[remaining];
+
+   if(!same_mem(&mac[0], included_tag, tag_size()))
+      throw Integrity_Failure("GCM tag check failed");
+
+   buffer.resize(offset + remaining);
+   }
+
+}
diff --git a/src/lib/modes/aead/gcm/gcm.h b/src/lib/modes/aead/gcm/gcm.h
new file mode 100644
index 000000000..12d66a3d1
--- /dev/null
+++ b/src/lib/modes/aead/gcm/gcm.h
@@ -0,0 +1,150 @@
+/*
+* GCM Mode
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_AEAD_GCM_H__
+#define BOTAN_AEAD_GCM_H__
+
+#include <botan/aead.h>
+#include <botan/block_cipher.h>
+#include <botan/stream_cipher.h>
+#include <memory>
+
+namespace Botan {
+
+class GHASH;
+
+/**
+* GCM Mode
+*/
+class BOTAN_DLL GCM_Mode : public AEAD_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      void set_associated_data(const byte ad[], size_t ad_len) override;
+
+      std::string name() const override;
+
+      size_t update_granularity() const;
+
+      Key_Length_Specification key_spec() const override;
+
+      // GCM supports arbitrary nonce lengths
+      bool valid_nonce_length(size_t) const override { return true; }
+
+      size_t tag_size() const { return m_tag_size; }
+
+      void clear();
+   protected:
+      void key_schedule(const byte key[], size_t length) override;
+
+      GCM_Mode(BlockCipher* cipher, size_t tag_size);
+
+      const size_t BS = 16;
+
+      const size_t m_tag_size;
+      const std::string m_cipher_name;
+
+      std::unique_ptr<StreamCipher> m_ctr;
+      std::unique_ptr<GHASH> m_ghash;
+   };
+
+/**
+* GCM Encryption
+*/
+class BOTAN_DLL GCM_Encryption : public GCM_Mode
+   {
+   public:
+      /**
+      * @param cipher the 128 bit block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      GCM_Encryption(BlockCipher* cipher, size_t tag_size = 16) :
+         GCM_Mode(cipher, tag_size) {}
+
+      size_t output_length(size_t input_length) const override
+         { return input_length + tag_size(); }
+
+      size_t minimum_final_size() const override { return 0; }
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   };
+
+/**
+* GCM Decryption
+*/
+class BOTAN_DLL GCM_Decryption : public GCM_Mode
+   {
+   public:
+      /**
+      * @param cipher the 128 bit block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      GCM_Decryption(BlockCipher* cipher, size_t tag_size = 16) :
+         GCM_Mode(cipher, tag_size) {}
+
+      size_t output_length(size_t input_length) const override
+         {
+         BOTAN_ASSERT(input_length > tag_size(), "Sufficient input");
+         return input_length - tag_size();
+         }
+
+      size_t minimum_final_size() const override { return tag_size(); }
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   };
+
+/**
+* GCM's GHASH
+* Maybe a Transform?
+*/
+class BOTAN_DLL GHASH : public SymmetricAlgorithm
+   {
+   public:
+      void set_associated_data(const byte ad[], size_t ad_len);
+
+      secure_vector<byte> nonce_hash(const byte nonce[], size_t len);
+
+      void start(const byte nonce[], size_t len);
+
+      /*
+      * Assumes input len is multiple of 16
+      */
+      void update(const byte in[], size_t len);
+
+      secure_vector<byte> final();
+
+      Key_Length_Specification key_spec() const { return Key_Length_Specification(16); }
+
+      void clear();
+
+      std::string name() const { return "GHASH"; }
+   private:
+      void key_schedule(const byte key[], size_t key_len) override;
+
+      void gcm_multiply(secure_vector<byte>& x) const;
+
+      void ghash_update(secure_vector<byte>& x,
+                        const byte input[], size_t input_len);
+
+      void add_final_block(secure_vector<byte>& x,
+                           size_t ad_len, size_t pt_len);
+
+      secure_vector<byte> m_H;
+      secure_vector<byte> m_H_ad;
+      secure_vector<byte> m_nonce;
+      secure_vector<byte> m_ghash;
+      size_t m_ad_len = 0, m_text_len = 0;
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/aead/gcm/info.txt b/src/lib/modes/aead/gcm/info.txt
new file mode 100644
index 000000000..cf5f68bb5
--- /dev/null
+++ b/src/lib/modes/aead/gcm/info.txt
@@ -0,0 +1,6 @@
+define AEAD_GCM 20131128
+
+<requires>
+block
+ctr
+</requires>
diff --git a/src/lib/modes/aead/info.txt b/src/lib/modes/aead/info.txt
new file mode 100644
index 000000000..102f05b7b
--- /dev/null
+++ b/src/lib/modes/aead/info.txt
@@ -0,0 +1 @@
+define AEAD_MODES 20131128
diff --git a/src/lib/modes/aead/ocb/info.txt b/src/lib/modes/aead/ocb/info.txt
new file mode 100644
index 000000000..be4cefdd0
--- /dev/null
+++ b/src/lib/modes/aead/ocb/info.txt
@@ -0,0 +1,6 @@
+define AEAD_OCB 20131128
+
+<requires>
+block
+cmac
+</requires>
diff --git a/src/lib/modes/aead/ocb/ocb.cpp b/src/lib/modes/aead/ocb/ocb.cpp
new file mode 100644
index 000000000..fd66bb2e9
--- /dev/null
+++ b/src/lib/modes/aead/ocb/ocb.cpp
@@ -0,0 +1,432 @@
+/*
+* OCB Mode
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/ocb.h>
+#include <botan/cmac.h>
+#include <botan/internal/xor_buf.h>
+#include <botan/internal/bit_ops.h>
+#include <algorithm>
+
+namespace Botan {
+
+namespace {
+
+const size_t BS = 16; // intrinsic to OCB definition
+
+}
+
+// Has to be in Botan namespace so unique_ptr can reference it
+class L_computer
+   {
+   public:
+      L_computer(const BlockCipher& cipher)
+         {
+         m_L_star.resize(cipher.block_size());
+         cipher.encrypt(m_L_star);
+         m_L_dollar = poly_double(star());
+         m_L.push_back(poly_double(dollar()));
+         }
+
+      const secure_vector<byte>& star() const { return m_L_star; }
+
+      const secure_vector<byte>& dollar() const { return m_L_dollar; }
+
+      const secure_vector<byte>& operator()(size_t i) const { return get(i); }
+
+      const secure_vector<byte>& compute_offsets(secure_vector<byte>& offset,
+                                                 size_t block_index,
+                                                 size_t blocks) const
+         {
+         m_offset_buf.resize(blocks*BS);
+
+         for(size_t i = 0; i != blocks; ++i)
+            { // could be done in parallel
+            offset ^= get(ctz(block_index + 1 + i));
+            copy_mem(&m_offset_buf[BS*i], &offset[0], BS);
+            }
+
+         return m_offset_buf;
+         }
+
+   private:
+      const secure_vector<byte>& get(size_t i) const
+         {
+         while(m_L.size() <= i)
+            m_L.push_back(poly_double(m_L.back()));
+
+         return m_L.at(i);
+         }
+
+      secure_vector<byte> poly_double(const secure_vector<byte>& in) const
+         {
+         return CMAC::poly_double(in, 0x87);
+         }
+
+      secure_vector<byte> m_L_dollar, m_L_star;
+      mutable std::vector<secure_vector<byte>> m_L;
+      mutable secure_vector<byte> m_offset_buf;
+   };
+
+namespace {
+
+/*
+* OCB's HASH
+*/
+secure_vector<byte> ocb_hash(const L_computer& L,
+                             const BlockCipher& cipher,
+                             const byte ad[], size_t ad_len)
+   {
+   secure_vector<byte> sum(BS);
+   secure_vector<byte> offset(BS);
+
+   secure_vector<byte> buf(BS);
+
+   const size_t ad_blocks = (ad_len / BS);
+   const size_t ad_remainder = (ad_len % BS);
+
+   for(size_t i = 0; i != ad_blocks; ++i)
+      {
+      // this loop could run in parallel
+      offset ^= L(ctz(i+1));
+
+      buf = offset;
+      xor_buf(&buf[0], &ad[BS*i], BS);
+
+      cipher.encrypt(buf);
+
+      sum ^= buf;
+      }
+
+   if(ad_remainder)
+      {
+      offset ^= L.star();
+
+      buf = offset;
+      xor_buf(&buf[0], &ad[BS*ad_blocks], ad_remainder);
+      buf[ad_len % BS] ^= 0x80;
+
+      cipher.encrypt(buf);
+
+      sum ^= buf;
+      }
+
+   return sum;
+   }
+
+}
+
+OCB_Mode::OCB_Mode(BlockCipher* cipher, size_t tag_size) :
+   m_cipher(cipher),
+   m_checksum(m_cipher->parallel_bytes()),
+   m_offset(BS),
+   m_ad_hash(BS),
+   m_tag_size(tag_size)
+   {
+   if(m_cipher->block_size() != BS)
+      throw std::invalid_argument("OCB requires a 128 bit cipher so cannot be used with " +
+                                  m_cipher->name());
+
+   if(m_tag_size != 8 && m_tag_size != 12 && m_tag_size != 16)
+      throw std::invalid_argument("OCB cannot produce a " + std::to_string(m_tag_size) +
+                                  " byte tag");
+
+   }
+
+OCB_Mode::~OCB_Mode() { /* for unique_ptr destructor */ }
+
+void OCB_Mode::clear()
+   {
+   m_cipher.reset();
+   m_L.reset();
+
+   zeroise(m_ad_hash);
+   zeroise(m_offset);
+   zeroise(m_checksum);
+   }
+
+bool OCB_Mode::valid_nonce_length(size_t length) const
+   {
+   return (length > 0 && length < 16);
+   }
+
+std::string OCB_Mode::name() const
+   {
+   return m_cipher->name() + "/OCB"; // include tag size
+   }
+
+size_t OCB_Mode::update_granularity() const
+   {
+   return m_cipher->parallel_bytes();
+   }
+
+Key_Length_Specification OCB_Mode::key_spec() const
+   {
+   return m_cipher->key_spec();
+   }
+
+void OCB_Mode::key_schedule(const byte key[], size_t length)
+   {
+   m_cipher->set_key(key, length);
+   m_L.reset(new L_computer(*m_cipher));
+   }
+
+void OCB_Mode::set_associated_data(const byte ad[], size_t ad_len)
+   {
+   BOTAN_ASSERT(m_L, "A key was set");
+   m_ad_hash = ocb_hash(*m_L, *m_cipher, &ad[0], ad_len);
+   }
+
+secure_vector<byte>
+OCB_Mode::update_nonce(const byte nonce[], size_t nonce_len)
+   {
+   BOTAN_ASSERT(nonce_len < BS, "Nonce is less than 128 bits");
+
+   secure_vector<byte> nonce_buf(BS);
+
+   copy_mem(&nonce_buf[BS - nonce_len], nonce, nonce_len);
+   nonce_buf[0] = ((tag_size() * 8) % 128) << 1;
+   nonce_buf[BS - nonce_len - 1] = 1;
+
+   const byte bottom = nonce_buf[15] & 0x3F;
+   nonce_buf[15] &= 0xC0;
+
+   const bool need_new_stretch = (m_last_nonce != nonce_buf);
+
+   if(need_new_stretch)
+      {
+      m_last_nonce = nonce_buf;
+
+      m_cipher->encrypt(nonce_buf);
+
+      for(size_t i = 0; i != 8; ++i)
+         nonce_buf.push_back(nonce_buf[i] ^ nonce_buf[i+1]);
+
+      m_stretch = nonce_buf;
+      }
+
+   // now set the offset from stretch and bottom
+
+   const size_t shift_bytes = bottom / 8;
+   const size_t shift_bits  = bottom % 8;
+
+   secure_vector<byte> offset(BS);
+   for(size_t i = 0; i != BS; ++i)
+      {
+      offset[i]  = (m_stretch[i+shift_bytes] << shift_bits);
+      offset[i] |= (m_stretch[i+shift_bytes+1] >> (8-shift_bits));
+      }
+
+   return offset;
+   }
+
+secure_vector<byte> OCB_Mode::start(const byte nonce[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   BOTAN_ASSERT(m_L, "A key was set");
+
+   m_offset = update_nonce(nonce, nonce_len);
+   zeroise(m_checksum);
+   m_block_index = 0;
+
+   return secure_vector<byte>();
+   }
+
+void OCB_Encryption::encrypt(byte buffer[], size_t blocks)
+   {
+   const L_computer& L = *m_L; // convenient name
+
+   const size_t par_blocks = m_checksum.size() / BS;
+
+   while(blocks)
+      {
+      const size_t proc_blocks = std::min(blocks, par_blocks);
+      const size_t proc_bytes = proc_blocks * BS;
+
+      const auto& offsets = L.compute_offsets(m_offset, m_block_index, proc_blocks);
+
+      xor_buf(&m_checksum[0], &buffer[0], proc_bytes);
+
+      xor_buf(&buffer[0], &offsets[0], proc_bytes);
+      m_cipher->encrypt_n(&buffer[0], &buffer[0], proc_blocks);
+      xor_buf(&buffer[0], &offsets[0], proc_bytes);
+
+      buffer += proc_bytes;
+      blocks -= proc_blocks;
+      m_block_index += proc_blocks;
+      }
+   }
+
+void OCB_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];
+
+   BOTAN_ASSERT(sz % BS == 0, "Input length is an even number of blocks");
+
+   encrypt(buf, sz / BS);
+   }
+
+void OCB_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];
+
+   if(sz)
+      {
+      const size_t final_full_blocks = sz / BS;
+      const size_t remainder_bytes = sz - (final_full_blocks * BS);
+
+      encrypt(buf, final_full_blocks);
+
+      if(remainder_bytes)
+         {
+         BOTAN_ASSERT(remainder_bytes < BS, "Only a partial block left");
+         byte* remainder = &buf[sz - remainder_bytes];
+
+         xor_buf(&m_checksum[0], &remainder[0], remainder_bytes);
+         m_checksum[remainder_bytes] ^= 0x80;
+
+         m_offset ^= m_L->star(); // Offset_*
+
+         secure_vector<byte> buf(BS);
+         m_cipher->encrypt(m_offset, buf);
+         xor_buf(&remainder[0], &buf[0], remainder_bytes);
+         }
+      }
+
+   secure_vector<byte> checksum(BS);
+
+   // fold checksum
+   for(size_t i = 0; i != m_checksum.size(); ++i)
+      checksum[i % checksum.size()] ^= m_checksum[i];
+
+   // now compute the tag
+   secure_vector<byte> mac = m_offset;
+   mac ^= checksum;
+   mac ^= m_L->dollar();
+
+   m_cipher->encrypt(mac);
+
+   mac ^= m_ad_hash;
+
+   buffer += std::make_pair(&mac[0], tag_size());
+
+   zeroise(m_checksum);
+   zeroise(m_offset);
+   m_block_index = 0;
+   }
+
+void OCB_Decryption::decrypt(byte buffer[], size_t blocks)
+   {
+   const L_computer& L = *m_L; // convenient name
+
+   const size_t par_bytes = m_cipher->parallel_bytes();
+
+   BOTAN_ASSERT(par_bytes % BS == 0, "Cipher is parallel in full blocks");
+
+   const size_t par_blocks = par_bytes / BS;
+
+   while(blocks)
+      {
+      const size_t proc_blocks = std::min(blocks, par_blocks);
+      const size_t proc_bytes = proc_blocks * BS;
+
+      const auto& offsets = L.compute_offsets(m_offset, m_block_index, proc_blocks);
+
+      xor_buf(&buffer[0], &offsets[0], proc_bytes);
+      m_cipher->decrypt_n(&buffer[0], &buffer[0], proc_blocks);
+      xor_buf(&buffer[0], &offsets[0], proc_bytes);
+
+      xor_buf(&m_checksum[0], &buffer[0], proc_bytes);
+
+      buffer += proc_bytes;
+      blocks -= proc_blocks;
+      m_block_index += proc_blocks;
+      }
+   }
+
+void OCB_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];
+
+   BOTAN_ASSERT(sz % BS == 0, "Input length is an even number of blocks");
+
+   decrypt(buf, sz / BS);
+   }
+
+void OCB_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 >= tag_size(), "We have the tag");
+
+   const size_t remaining = sz - tag_size();
+
+   if(remaining)
+      {
+      const size_t final_full_blocks = remaining / BS;
+      const size_t final_bytes = remaining - (final_full_blocks * BS);
+
+      decrypt(&buf[0], final_full_blocks);
+
+      if(final_bytes)
+         {
+         BOTAN_ASSERT(final_bytes < BS, "Only a partial block left");
+
+         byte* remainder = &buf[remaining - final_bytes];
+
+         m_offset ^= m_L->star(); // Offset_*
+
+         secure_vector<byte> pad(BS);
+         m_cipher->encrypt(m_offset, pad); // P_*
+
+         xor_buf(&remainder[0], &pad[0], final_bytes);
+
+         xor_buf(&m_checksum[0], &remainder[0], final_bytes);
+         m_checksum[final_bytes] ^= 0x80;
+         }
+      }
+
+   secure_vector<byte> checksum(BS);
+
+   // fold checksum
+   for(size_t i = 0; i != m_checksum.size(); ++i)
+      checksum[i % checksum.size()] ^= m_checksum[i];
+
+   // compute the mac
+   secure_vector<byte> mac = m_offset;
+   mac ^= checksum;
+   mac ^= m_L->dollar();
+
+   m_cipher->encrypt(mac);
+
+   mac ^= m_ad_hash;
+
+   // reset state
+   zeroise(m_checksum);
+   zeroise(m_offset);
+   m_block_index = 0;
+
+   // compare mac
+   const byte* included_tag = &buf[remaining];
+
+   if(!same_mem(&mac[0], included_tag, tag_size()))
+      throw Integrity_Failure("OCB tag check failed");
+
+   // remove tag from end of message
+   buffer.resize(remaining + offset);
+   }
+
+}
diff --git a/src/lib/modes/aead/ocb/ocb.h b/src/lib/modes/aead/ocb/ocb.h
new file mode 100644
index 000000000..e7d042de3
--- /dev/null
+++ b/src/lib/modes/aead/ocb/ocb.h
@@ -0,0 +1,124 @@
+/*
+* OCB Mode
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_AEAD_OCB_H__
+#define BOTAN_AEAD_OCB_H__
+
+#include <botan/aead.h>
+#include <botan/block_cipher.h>
+#include <botan/buf_filt.h>
+#include <memory>
+
+namespace Botan {
+
+class L_computer;
+
+/**
+* OCB Mode (base class for OCB_Encryption and OCB_Decryption). Note
+* that OCB is patented, but is freely licensed in some circumstances.
+*
+* @see "The OCB Authenticated-Encryption Algorithm" internet draft
+        http://tools.ietf.org/html/draft-irtf-cfrg-ocb-03
+* @see Free Licenses http://www.cs.ucdavis.edu/~rogaway/ocb/license.htm
+* @see OCB home page http://www.cs.ucdavis.edu/~rogaway/ocb
+*/
+class BOTAN_DLL OCB_Mode : public AEAD_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      void set_associated_data(const byte ad[], size_t ad_len) override;
+
+      std::string name() const override;
+
+      size_t update_granularity() const;
+
+      Key_Length_Specification key_spec() const override;
+
+      bool valid_nonce_length(size_t) const override;
+
+      size_t tag_size() const { return m_tag_size; }
+
+      void clear();
+
+      ~OCB_Mode();
+   protected:
+      /**
+      * @param cipher the 128-bit block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      OCB_Mode(BlockCipher* cipher, size_t tag_size);
+
+      void key_schedule(const byte key[], size_t length) override;
+
+      // fixme make these private
+      std::unique_ptr<BlockCipher> m_cipher;
+      std::unique_ptr<L_computer> m_L;
+
+      size_t m_block_index = 0;
+
+      secure_vector<byte> m_checksum;
+      secure_vector<byte> m_offset;
+      secure_vector<byte> m_ad_hash;
+   private:
+      secure_vector<byte> update_nonce(const byte nonce[], size_t nonce_len);
+
+      size_t m_tag_size = 0;
+      secure_vector<byte> m_last_nonce;
+      secure_vector<byte> m_stretch;
+   };
+
+class BOTAN_DLL OCB_Encryption : public OCB_Mode
+   {
+   public:
+      /**
+      * @param cipher the 128-bit block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      OCB_Encryption(BlockCipher* cipher, size_t tag_size = 16) :
+         OCB_Mode(cipher, tag_size) {}
+
+      size_t output_length(size_t input_length) const override
+         { return input_length + tag_size(); }
+
+      size_t minimum_final_size() const override { return 0; }
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   private:
+      void encrypt(byte input[], size_t blocks);
+   };
+
+class BOTAN_DLL OCB_Decryption : public OCB_Mode
+   {
+   public:
+      /**
+      * @param cipher the 128-bit block cipher to use
+      * @param tag_size is how big the auth tag will be
+      */
+      OCB_Decryption(BlockCipher* cipher, size_t tag_size = 16) :
+         OCB_Mode(cipher, tag_size) {}
+
+      size_t output_length(size_t input_length) const override
+         {
+         BOTAN_ASSERT(input_length > tag_size(), "Sufficient input");
+         return input_length - tag_size();
+         }
+
+      size_t minimum_final_size() const override { return tag_size(); }
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   private:
+      void decrypt(byte input[], size_t blocks);
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/aead/siv/info.txt b/src/lib/modes/aead/siv/info.txt
new file mode 100644
index 000000000..b1e38568e
--- /dev/null
+++ b/src/lib/modes/aead/siv/info.txt
@@ -0,0 +1,3 @@
+define AEAD_SIV 20131202
+
+load_on auto
diff --git a/src/lib/modes/aead/siv/siv.cpp b/src/lib/modes/aead/siv/siv.cpp
new file mode 100644
index 000000000..a89c3dd08
--- /dev/null
+++ b/src/lib/modes/aead/siv/siv.cpp
@@ -0,0 +1,180 @@
+/*
+* SIV Mode Encryption
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/siv.h>
+#include <botan/cmac.h>
+#include <botan/ctr.h>
+#include <botan/parsing.h>
+#include <botan/internal/xor_buf.h>
+#include <algorithm>
+
+namespace Botan {
+
+SIV_Mode::SIV_Mode(BlockCipher* cipher) :
+   m_name(cipher->name() + "/SIV"),
+   m_ctr(new CTR_BE(cipher->clone())),
+   m_cmac(new CMAC(cipher))
+   {
+   }
+
+void SIV_Mode::clear()
+   {
+   m_ctr.reset();
+   m_nonce.clear();
+   m_msg_buf.clear();
+   m_ad_macs.clear();
+   }
+
+std::string SIV_Mode::name() const
+   {
+   return m_name;
+   }
+
+bool SIV_Mode::valid_nonce_length(size_t) const
+   {
+   return true;
+   }
+
+size_t SIV_Mode::update_granularity() const
+   {
+   /*
+   This value does not particularly matter as regardless SIV_Mode::update
+   buffers all input, so in theory this could be 1. However as for instance
+   Transformation_Filter creates update_granularity() byte buffers, use a
+   somewhat large size to avoid bouncing on a tiny buffer.
+   */
+   return 128;
+   }
+
+Key_Length_Specification SIV_Mode::key_spec() const
+   {
+   return m_cmac->key_spec().multiple(2);
+   }
+
+void SIV_Mode::key_schedule(const byte key[], size_t length)
+   {
+   const size_t keylen = length / 2;
+   m_cmac->set_key(key, keylen);
+   m_ctr->set_key(key + keylen, keylen);
+   m_ad_macs.clear();
+   }
+
+void SIV_Mode::set_associated_data_n(size_t n, const byte ad[], size_t length)
+   {
+   if(n >= m_ad_macs.size())
+      m_ad_macs.resize(n+1);
+
+   m_ad_macs[n] = m_cmac->process(ad, length);
+   }
+
+secure_vector<byte> SIV_Mode::start(const byte nonce[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   if(nonce_len)
+      m_nonce = m_cmac->process(nonce, nonce_len);
+   else
+      m_nonce.clear();
+
+   m_msg_buf.clear();
+
+   return secure_vector<byte>();
+   }
+
+void SIV_Mode::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];
+
+   m_msg_buf.insert(m_msg_buf.end(), buf, buf + sz);
+   buffer.resize(offset); // truncate msg
+   }
+
+secure_vector<byte> SIV_Mode::S2V(const byte* text, size_t text_len)
+   {
+   const byte zero[16] = { 0 };
+
+   secure_vector<byte> V = cmac().process(zero, 16);
+
+   for(size_t i = 0; i != m_ad_macs.size(); ++i)
+      {
+      V = CMAC::poly_double(V, 0x87);
+      V ^= m_ad_macs[i];
+      }
+
+   if(m_nonce.size())
+      {
+      V = CMAC::poly_double(V, 0x87);
+      V ^= m_nonce;
+      }
+
+   if(text_len < 16)
+      {
+      V = CMAC::poly_double(V, 0x87);
+      xor_buf(&V[0], text, text_len);
+      V[text_len] ^= 0x80;
+      return cmac().process(V);
+      }
+
+   cmac().update(text, text_len - 16);
+   xor_buf(&V[0], &text[text_len - 16], 16);
+   cmac().update(V);
+
+   return cmac().final();
+   }
+
+void SIV_Mode::set_ctr_iv(secure_vector<byte> V)
+   {
+   V[8] &= 0x7F;
+   V[12] &= 0x7F;
+
+   ctr().set_iv(&V[0], V.size());
+   }
+
+void SIV_Encryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+
+   buffer.insert(buffer.begin() + offset, msg_buf().begin(), msg_buf().end());
+
+   secure_vector<byte> V = S2V(&buffer[offset], buffer.size() - offset);
+
+   buffer.insert(buffer.begin() + offset, V.begin(), V.end());
+
+   set_ctr_iv(V);
+   ctr().cipher1(&buffer[offset + V.size()], buffer.size() - offset - V.size());
+   }
+
+void SIV_Decryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+
+   buffer.insert(buffer.begin() + offset, msg_buf().begin(), msg_buf().end());
+
+   const size_t sz = buffer.size() - offset;
+
+   BOTAN_ASSERT(sz >= tag_size(), "We have the tag");
+
+   secure_vector<byte> V(&buffer[offset], &buffer[offset + 16]);
+
+   set_ctr_iv(V);
+
+   ctr().cipher(&buffer[offset + V.size()],
+                &buffer[offset],
+                buffer.size() - offset - V.size());
+
+   secure_vector<byte> T = S2V(&buffer[offset], buffer.size() - offset - V.size());
+
+   if(T != V)
+      throw Integrity_Failure("SIV tag check failed");
+
+   buffer.resize(buffer.size() - tag_size());
+   }
+
+}
diff --git a/src/lib/modes/aead/siv/siv.h b/src/lib/modes/aead/siv/siv.h
new file mode 100644
index 000000000..31df4d049
--- /dev/null
+++ b/src/lib/modes/aead/siv/siv.h
@@ -0,0 +1,114 @@
+/*
+* SIV Mode
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_AEAD_SIV_H__
+#define BOTAN_AEAD_SIV_H__
+
+#include <botan/aead.h>
+#include <botan/block_cipher.h>
+#include <botan/stream_cipher.h>
+#include <botan/mac.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* Base class for SIV encryption and decryption (@see RFC 5297)
+*/
+class BOTAN_DLL SIV_Mode : public AEAD_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void set_associated_data_n(size_t n, const byte ad[], size_t ad_len);
+
+      void set_associated_data(const byte ad[], size_t ad_len) override
+         {
+         set_associated_data_n(0, ad, ad_len);
+         }
+
+      std::string name() const override;
+
+      size_t update_granularity() const;
+
+      Key_Length_Specification key_spec() const override;
+
+      bool valid_nonce_length(size_t) const override;
+
+      void clear();
+
+      size_t tag_size() const { return 16; }
+
+   protected:
+      SIV_Mode(BlockCipher* cipher);
+
+      StreamCipher& ctr() { return *m_ctr; }
+
+      void set_ctr_iv(secure_vector<byte> V);
+
+      secure_vector<byte>& msg_buf() { return m_msg_buf; }
+
+      secure_vector<byte> S2V(const byte text[], size_t text_len);
+   private:
+      MessageAuthenticationCode& cmac() { return *m_cmac; }
+
+      void key_schedule(const byte key[], size_t length) override;
+
+      const std::string m_name;
+
+      std::unique_ptr<StreamCipher> m_ctr;
+      std::unique_ptr<MessageAuthenticationCode> m_cmac;
+      secure_vector<byte> m_nonce, m_msg_buf;
+      std::vector<secure_vector<byte>> m_ad_macs;
+   };
+
+/**
+* SIV Encryption
+*/
+class BOTAN_DLL SIV_Encryption : public SIV_Mode
+   {
+   public:
+      /**
+      * @param cipher a block cipher
+      */
+      SIV_Encryption(BlockCipher* cipher) : SIV_Mode(cipher) {}
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override
+         { return input_length + tag_size(); }
+
+      size_t minimum_final_size() const override { return 0; }
+   };
+
+/**
+* SIV Decryption
+*/
+class BOTAN_DLL SIV_Decryption : public SIV_Mode
+   {
+   public:
+      /**
+      * @param cipher a 128-bit block cipher
+      */
+      SIV_Decryption(BlockCipher* cipher) : SIV_Mode(cipher) {}
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override
+         {
+         BOTAN_ASSERT(input_length > tag_size(), "Sufficient input");
+         return input_length - tag_size();
+         }
+
+      size_t minimum_final_size() const override { return tag_size(); }
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/cbc/cbc.cpp b/src/lib/modes/cbc/cbc.cpp
new file mode 100644
index 000000000..31834bade
--- /dev/null
+++ b/src/lib/modes/cbc/cbc.cpp
@@ -0,0 +1,299 @@
+/*
+* CBC Mode
+* (C) 1999-2007,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/cbc.h>
+#include <botan/loadstor.h>
+#include <botan/internal/xor_buf.h>
+#include <botan/internal/rounding.h>
+
+namespace Botan {
+
+CBC_Mode::CBC_Mode(BlockCipher* cipher, BlockCipherModePaddingMethod* padding) :
+   m_cipher(cipher),
+   m_padding(padding),
+   m_state(m_cipher->block_size())
+   {
+   if(m_padding && !m_padding->valid_blocksize(cipher->block_size()))
+      throw std::invalid_argument("Padding " + m_padding->name() +
+                                  " cannot be used with " +
+                                  cipher->name() + "/CBC");
+   }
+
+void CBC_Mode::clear()
+   {
+   m_cipher->clear();
+   m_state.clear();
+   }
+
+std::string CBC_Mode::name() const
+   {
+   if(m_padding)
+      return cipher().name() + "/CBC/" + padding().name();
+   else
+      return cipher().name() + "/CBC/CTS";
+   }
+
+size_t CBC_Mode::update_granularity() const
+   {
+   return cipher().parallel_bytes();
+   }
+
+Key_Length_Specification CBC_Mode::key_spec() const
+   {
+   return cipher().key_spec();
+   }
+
+size_t CBC_Mode::default_nonce_length() const
+   {
+   return cipher().block_size();
+   }
+
+bool CBC_Mode::valid_nonce_length(size_t n) const
+   {
+   return (n == 0 || n == cipher().block_size());
+   }
+
+void CBC_Mode::key_schedule(const byte key[], size_t length)
+   {
+   m_cipher->set_key(key, length);
+   }
+
+secure_vector<byte> CBC_Mode::start(const byte nonce[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   /*
+   * A nonce of zero length means carry the last ciphertext value over
+   * as the new IV, as unfortunately some protocols require this. If
+   * this is the first message then we use an IV of all zeros.
+   */
+   if(nonce_len)
+      m_state.assign(nonce, nonce + nonce_len);
+
+   return secure_vector<byte>();
+   }
+
+size_t CBC_Encryption::minimum_final_size() const
+   {
+   return 0;
+   }
+
+size_t CBC_Encryption::output_length(size_t input_length) const
+   {
+   return round_up(input_length, cipher().block_size());
+   }
+
+void CBC_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, "CBC input is full blocks");
+   const size_t blocks = sz / BS;
+
+   if(blocks)
+      {
+      xor_buf(&buf[0], state_ptr(), BS);
+      cipher().encrypt(&buf[0]);
+
+      for(size_t i = 1; i != blocks; ++i)
+         {
+         xor_buf(&buf[BS*i], &buf[BS*(i-1)], BS);
+         cipher().encrypt(&buf[BS*i]);
+         }
+
+      state().assign(&buf[BS*(blocks-1)], &buf[BS*blocks]);
+      }
+   }
+
+void CBC_Encryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+
+   const size_t BS = cipher().block_size();
+
+   const size_t bytes_in_final_block = (buffer.size()-offset) % BS;
+
+   padding().add_padding(buffer, bytes_in_final_block, BS);
+
+   if((buffer.size()-offset) % BS)
+      throw std::runtime_error("Did not pad to full block size in " + name());
+
+   update(buffer, offset);
+   }
+
+bool CTS_Encryption::valid_nonce_length(size_t n) const
+   {
+   return (n == cipher().block_size());
+   }
+
+size_t CTS_Encryption::minimum_final_size() const
+   {
+   return cipher().block_size() + 1;
+   }
+
+size_t CTS_Encryption::output_length(size_t input_length) const
+   {
+   return input_length; // no ciphertext expansion in CTS
+   }
+
+void CTS_Encryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+   byte* buf = &buffer[offset];
+   const size_t sz = buffer.size() - offset;
+
+   const size_t BS = cipher().block_size();
+
+   if(sz < BS + 1)
+      throw Encoding_Error(name() + ": insufficient data to encrypt");
+
+   if(sz % BS == 0)
+      {
+      update(buffer, offset);
+
+      // swap last two blocks
+      for(size_t i = 0; i != BS; ++i)
+         std::swap(buffer[buffer.size()-BS+i], buffer[buffer.size()-2*BS+i]);
+      }
+   else
+      {
+      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[0], state_ptr(), BS);
+      cipher().encrypt(&last[0]);
+
+      for(size_t i = 0; i != final_bytes - BS; ++i)
+         {
+         std::swap(last[i], last[i + BS]);
+         last[i] ^= last[i + BS];
+         }
+
+      cipher().encrypt(&last[0]);
+
+      buffer += last;
+      }
+   }
+
+size_t CBC_Decryption::output_length(size_t input_length) const
+   {
+   return input_length; // precise for CTS, worst case otherwise
+   }
+
+size_t CBC_Decryption::minimum_final_size() const
+   {
+   return cipher().block_size();
+   }
+
+void CBC_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;
+
+   while(blocks)
+      {
+      const size_t to_proc = std::min(BS * blocks, m_tempbuf.size());
+
+      cipher().decrypt_n(buf, &m_tempbuf[0], to_proc / BS);
+
+      xor_buf(&m_tempbuf[0], state_ptr(), BS);
+      xor_buf(&m_tempbuf[BS], buf, to_proc - BS);
+      copy_mem(state_ptr(), buf + (to_proc - BS), BS);
+
+      copy_mem(buf, &m_tempbuf[0], to_proc);
+
+      buf += to_proc;
+      blocks -= to_proc / BS;
+      }
+   }
+
+void CBC_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
+   }
+
+bool CTS_Decryption::valid_nonce_length(size_t n) const
+   {
+   return (n == cipher().block_size());
+   }
+
+size_t CTS_Decryption::minimum_final_size() const
+   {
+   return cipher().block_size() + 1;
+   }
+
+void CTS_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];
+
+   const size_t BS = cipher().block_size();
+
+   if(sz < BS + 1)
+      throw Encoding_Error(name() + ": insufficient data to decrypt");
+
+   if(sz % BS == 0)
+      {
+      // swap last two blocks
+      for(size_t i = 0; i != BS; ++i)
+         std::swap(buffer[buffer.size()-BS+i], buffer[buffer.size()-2*BS+i]);
+
+      update(buffer, offset);
+      }
+   else
+      {
+      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);
+
+      cipher().decrypt(&last[0]);
+      xor_buf(&last[0], &last[BS], final_bytes - BS);
+
+      for(size_t i = 0; i != final_bytes - BS; ++i)
+         std::swap(last[i], last[i + BS]);
+
+      cipher().decrypt(&last[0]);
+      xor_buf(&last[0], state_ptr(), BS);
+
+      buffer += last;
+      }
+
+   }
+
+}
diff --git a/src/lib/modes/cbc/cbc.h b/src/lib/modes/cbc/cbc.h
new file mode 100644
index 000000000..0a10f3661
--- /dev/null
+++ b/src/lib/modes/cbc/cbc.h
@@ -0,0 +1,132 @@
+/*
+* CBC mode
+* (C) 1999-2007,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_MODE_CBC_H__
+#define BOTAN_MODE_CBC_H__
+
+#include <botan/cipher_mode.h>
+#include <botan/block_cipher.h>
+#include <botan/mode_pad.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* CBC Mode
+*/
+class BOTAN_DLL CBC_Mode : public Cipher_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      std::string name() const override;
+
+      size_t update_granularity() const override;
+
+      Key_Length_Specification key_spec() const override;
+
+      size_t default_nonce_length() const override;
+
+      bool valid_nonce_length(size_t n) const override;
+
+      void clear();
+   protected:
+      CBC_Mode(BlockCipher* cipher, BlockCipherModePaddingMethod* padding);
+
+      const BlockCipher& cipher() const { return *m_cipher; }
+
+      const BlockCipherModePaddingMethod& padding() const
+         {
+         BOTAN_ASSERT_NONNULL(m_padding);
+         return *m_padding;
+         }
+
+      secure_vector<byte>& state() { return m_state; }
+
+      byte* state_ptr() { return &m_state[0]; }
+
+   private:
+      void key_schedule(const byte key[], size_t length) override;
+
+      std::unique_ptr<BlockCipher> m_cipher;
+      std::unique_ptr<BlockCipherModePaddingMethod> m_padding;
+      secure_vector<byte> m_state;
+   };
+
+/**
+* CBC Encryption
+*/
+class BOTAN_DLL CBC_Encryption : public CBC_Mode
+   {
+   public:
+      CBC_Encryption(BlockCipher* cipher, BlockCipherModePaddingMethod* padding) :
+         CBC_Mode(cipher, padding) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override;
+
+      size_t minimum_final_size() const override;
+   };
+
+/**
+* CBC Encryption with ciphertext stealing (CBC-CS3 variant)
+*/
+class BOTAN_DLL CTS_Encryption : public CBC_Encryption
+   {
+   public:
+      CTS_Encryption(BlockCipher* cipher) : CBC_Encryption(cipher, nullptr) {}
+
+      size_t output_length(size_t input_length) const override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t minimum_final_size() const override;
+
+      bool valid_nonce_length(size_t n) const;
+   };
+
+/**
+* CBC Decryption
+*/
+class BOTAN_DLL CBC_Decryption : public CBC_Mode
+   {
+   public:
+      CBC_Decryption(BlockCipher* cipher, BlockCipherModePaddingMethod* padding) :
+         CBC_Mode(cipher, padding), m_tempbuf(update_granularity()) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override;
+
+      size_t minimum_final_size() const override;
+   private:
+      secure_vector<byte> m_tempbuf;
+   };
+
+/**
+* CBC Decryption with ciphertext stealing (CBC-CS3 variant)
+*/
+class BOTAN_DLL CTS_Decryption : public CBC_Decryption
+   {
+   public:
+      CTS_Decryption(BlockCipher* cipher) : CBC_Decryption(cipher, nullptr) {}
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t minimum_final_size() const override;
+
+      bool valid_nonce_length(size_t n) const;
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/cbc/info.txt b/src/lib/modes/cbc/info.txt
new file mode 100644
index 000000000..ce59deba0
--- /dev/null
+++ b/src/lib/modes/cbc/info.txt
@@ -0,0 +1,5 @@
+define MODE_CBC 20131128
+
+<requires>
+mode_pad
+</requires>
diff --git a/src/lib/modes/cfb/cfb.cpp b/src/lib/modes/cfb/cfb.cpp
new file mode 100644
index 000000000..7721e1487
--- /dev/null
+++ b/src/lib/modes/cfb/cfb.cpp
@@ -0,0 +1,150 @@
+/*
+* CFB Mode
+* (C) 1999-2007,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/cfb.h>
+#include <botan/parsing.h>
+#include <botan/internal/xor_buf.h>
+
+namespace Botan {
+
+CFB_Mode::CFB_Mode(BlockCipher* cipher, size_t feedback_bits) :
+   m_cipher(cipher),
+   m_feedback_bytes(feedback_bits ? feedback_bits / 8 : cipher->block_size())
+   {
+   if(feedback_bits % 8 || feedback() > cipher->block_size())
+      throw std::invalid_argument(name() + ": feedback bits " +
+                                  std::to_string(feedback_bits) + " not supported");
+   }
+
+void CFB_Mode::clear()
+   {
+   m_cipher->clear();
+   m_shift_register.clear();
+   }
+
+std::string CFB_Mode::name() const
+   {
+   if(feedback() == cipher().block_size())
+      return cipher().name() + "/CFB";
+   else
+      return cipher().name() + "/CFB(" + std::to_string(feedback()*8) + ")";
+   }
+
+size_t CFB_Mode::output_length(size_t input_length) const
+   {
+   return input_length;
+   }
+
+size_t CFB_Mode::update_granularity() const
+   {
+   return feedback();
+   }
+
+size_t CFB_Mode::minimum_final_size() const
+   {
+   return 0;
+   }
+
+Key_Length_Specification CFB_Mode::key_spec() const
+   {
+   return cipher().key_spec();
+   }
+
+size_t CFB_Mode::default_nonce_length() const
+   {
+   return cipher().block_size();
+   }
+
+bool CFB_Mode::valid_nonce_length(size_t n) const
+   {
+   return (n == cipher().block_size());
+   }
+
+void CFB_Mode::key_schedule(const byte key[], size_t length)
+   {
+   m_cipher->set_key(key, length);
+   }
+
+secure_vector<byte> CFB_Mode::start(const byte nonce[], size_t nonce_len)
+   {
+   if(!valid_nonce_length(nonce_len))
+      throw Invalid_IV_Length(name(), nonce_len);
+
+   m_shift_register.assign(nonce, nonce + nonce_len);
+   m_keystream_buf.resize(m_shift_register.size());
+   cipher().encrypt(m_shift_register, m_keystream_buf);
+
+   return secure_vector<byte>();
+   }
+
+void CFB_Encryption::update(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+   size_t sz = buffer.size() - offset;
+   byte* buf = &buffer[offset];
+
+   const size_t BS = cipher().block_size();
+
+   secure_vector<byte>& state = shift_register();
+   const size_t shift = feedback();
+
+   while(sz)
+      {
+      const size_t took = std::min(shift, sz);
+      xor_buf(&buf[0], &keystream_buf()[0], took);
+
+      // Assumes feedback-sized block except for last input
+      copy_mem(&state[0], &state[shift], BS - shift);
+      copy_mem(&state[BS-shift], &buf[0], shift);
+      cipher().encrypt(state, keystream_buf());
+
+      buf += took;
+      sz -= took;
+      }
+   }
+
+void CFB_Encryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   update(buffer, offset);
+   }
+
+void CFB_Decryption::update(secure_vector<byte>& buffer, size_t offset)
+   {
+   BOTAN_ASSERT(buffer.size() >= offset, "Offset is sane");
+   size_t sz = buffer.size() - offset;
+   byte* buf = &buffer[offset];
+
+   const size_t BS = cipher().block_size();
+
+   secure_vector<byte>& state = shift_register();
+   const size_t shift = feedback();
+
+   while(sz)
+      {
+      const size_t took = std::min(shift, sz);
+
+      // first update shift register with ciphertext
+      copy_mem(&state[0], &state[shift], BS - shift);
+      copy_mem(&state[BS-shift], &buf[0], took);
+
+      // then decrypt
+      xor_buf(&buf[0], &keystream_buf()[0], took);
+
+      // then update keystream
+      cipher().encrypt(state, keystream_buf());
+
+      buf += took;
+      sz -= took;
+      }
+   }
+
+void CFB_Decryption::finish(secure_vector<byte>& buffer, size_t offset)
+   {
+   update(buffer, offset);
+   }
+
+}
diff --git a/src/lib/modes/cfb/cfb.h b/src/lib/modes/cfb/cfb.h
new file mode 100644
index 000000000..48be0a2d9
--- /dev/null
+++ b/src/lib/modes/cfb/cfb.h
@@ -0,0 +1,91 @@
+/*
+* CFB mode
+* (C) 1999-2007,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_MODE_CFB_H__
+#define BOTAN_MODE_CFB_H__
+
+#include <botan/cipher_mode.h>
+#include <botan/block_cipher.h>
+#include <botan/mode_pad.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* CFB Mode
+*/
+class BOTAN_DLL CFB_Mode : public Cipher_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      std::string name() const override;
+
+      size_t update_granularity() const override;
+
+      size_t minimum_final_size() const override;
+
+      Key_Length_Specification key_spec() const override;
+
+      size_t output_length(size_t input_length) const override;
+
+      size_t default_nonce_length() const override;
+
+      bool valid_nonce_length(size_t n) const override;
+
+      void clear();
+   protected:
+      CFB_Mode(BlockCipher* cipher, size_t feedback_bits);
+
+      const BlockCipher& cipher() const { return *m_cipher; }
+
+      size_t feedback() const { return m_feedback_bytes; }
+
+      secure_vector<byte>& shift_register() { return m_shift_register; }
+
+      secure_vector<byte>& keystream_buf() { return m_keystream_buf; }
+
+   private:
+      void key_schedule(const byte key[], size_t length) override;
+
+      std::unique_ptr<BlockCipher> m_cipher;
+      secure_vector<byte> m_shift_register;
+      secure_vector<byte> m_keystream_buf;
+      size_t m_feedback_bytes;
+   };
+
+/**
+* CFB Encryption
+*/
+class BOTAN_DLL CFB_Encryption : public CFB_Mode
+   {
+   public:
+      CFB_Encryption(BlockCipher* cipher, size_t feedback_bits) :
+         CFB_Mode(cipher, feedback_bits) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   };
+
+/**
+* CFB Decryption
+*/
+class BOTAN_DLL CFB_Decryption : public CFB_Mode
+   {
+   public:
+      CFB_Decryption(BlockCipher* cipher, size_t feedback_bits) :
+         CFB_Mode(cipher, feedback_bits) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/cfb/info.txt b/src/lib/modes/cfb/info.txt
new file mode 100644
index 000000000..8d0e20a84
--- /dev/null
+++ b/src/lib/modes/cfb/info.txt
@@ -0,0 +1 @@
+define MODE_CFB 20131128
diff --git a/src/lib/modes/cipher_mode.h b/src/lib/modes/cipher_mode.h
new file mode 100644
index 000000000..91e2af5a9
--- /dev/null
+++ b/src/lib/modes/cipher_mode.h
@@ -0,0 +1,30 @@
+/*
+* Cipher Modes
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_CIPHER_MODE_H__
+#define BOTAN_CIPHER_MODE_H__
+
+#include <botan/transform.h>
+
+namespace Botan {
+
+/**
+* Interface for cipher modes
+*/
+class BOTAN_DLL Cipher_Mode : public Transformation
+   {
+   public:
+      /**
+      * Returns true iff this mode provides authentication as well as
+      * confidentiality.
+      */
+      virtual bool authenticated() const { return false; }
+   };
+
+}
+
+#endif
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
+   }
+
+}
diff --git a/src/lib/modes/ecb/ecb.h b/src/lib/modes/ecb/ecb.h
new file mode 100644
index 000000000..441eafbc1
--- /dev/null
+++ b/src/lib/modes/ecb/ecb.h
@@ -0,0 +1,89 @@
+/*
+* ECB Mode
+* (C) 1999-2009,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_MODE_ECB_H__
+#define BOTAN_MODE_ECB_H__
+
+#include <botan/cipher_mode.h>
+#include <botan/block_cipher.h>
+#include <botan/mode_pad.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* ECB mode
+*/
+class BOTAN_DLL ECB_Mode : public Cipher_Mode
+   {
+   public:
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      std::string name() const override;
+
+      size_t update_granularity() const override;
+
+      Key_Length_Specification key_spec() const override;
+
+      size_t default_nonce_length() const override;
+
+      bool valid_nonce_length(size_t n) const override;
+
+      void clear();
+   protected:
+      ECB_Mode(BlockCipher* cipher, BlockCipherModePaddingMethod* padding);
+
+      const BlockCipher& cipher() const { return *m_cipher; }
+
+      const BlockCipherModePaddingMethod& padding() const { return *m_padding; }
+
+   private:
+      void key_schedule(const byte key[], size_t length) override;
+
+      std::unique_ptr<BlockCipher> m_cipher;
+      std::unique_ptr<BlockCipherModePaddingMethod> m_padding;
+   };
+
+/**
+* ECB Encryption
+*/
+class BOTAN_DLL ECB_Encryption : public ECB_Mode
+   {
+   public:
+      ECB_Encryption(BlockCipher* cipher, BlockCipherModePaddingMethod* padding) :
+         ECB_Mode(cipher, padding) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override;
+
+      size_t minimum_final_size() const override;
+   };
+
+/**
+* ECB Decryption
+*/
+class BOTAN_DLL ECB_Decryption : public ECB_Mode
+   {
+   public:
+      ECB_Decryption(BlockCipher* cipher, BlockCipherModePaddingMethod* padding) :
+         ECB_Mode(cipher, padding) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override;
+
+      size_t minimum_final_size() const override;
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/ecb/info.txt b/src/lib/modes/ecb/info.txt
new file mode 100644
index 000000000..5e7737717
--- /dev/null
+++ b/src/lib/modes/ecb/info.txt
@@ -0,0 +1,5 @@
+define MODE_ECB 20131128
+
+<requires>
+mode_pad
+</requires>
diff --git a/src/lib/modes/info.txt b/src/lib/modes/info.txt
new file mode 100644
index 000000000..0dcb0cd59
--- /dev/null
+++ b/src/lib/modes/info.txt
@@ -0,0 +1,4 @@
+
+<requires>
+block
+</requires>
diff --git a/src/lib/modes/mode_pad/info.txt b/src/lib/modes/mode_pad/info.txt
new file mode 100644
index 000000000..e9df6334b
--- /dev/null
+++ b/src/lib/modes/mode_pad/info.txt
@@ -0,0 +1 @@
+define CIPHER_MODE_PADDING 20131128
diff --git a/src/lib/modes/mode_pad/mode_pad.cpp b/src/lib/modes/mode_pad/mode_pad.cpp
new file mode 100644
index 000000000..918964c74
--- /dev/null
+++ b/src/lib/modes/mode_pad/mode_pad.cpp
@@ -0,0 +1,103 @@
+/*
+* CBC Padding Methods
+* (C) 1999-2007,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/mode_pad.h>
+#include <botan/exceptn.h>
+
+namespace Botan {
+
+/*
+* Pad with PKCS #7 Method
+*/
+void PKCS7_Padding::add_padding(secure_vector<byte>& buffer,
+                                size_t last_byte_pos,
+                                size_t block_size) const
+   {
+   const byte pad_value = block_size - last_byte_pos;
+
+   for(size_t i = 0; i != pad_value; ++i)
+      buffer.push_back(pad_value);
+   }
+
+/*
+* Unpad with PKCS #7 Method
+*/
+size_t PKCS7_Padding::unpad(const byte block[], size_t size) const
+   {
+   size_t position = block[size-1];
+
+   if(position > size)
+      throw Decoding_Error("Bad padding in " + name());
+
+   for(size_t j = size-position; j != size-1; ++j)
+      if(block[j] != position)
+         throw Decoding_Error("Bad padding in " + name());
+
+   return (size-position);
+   }
+
+/*
+* Pad with ANSI X9.23 Method
+*/
+void ANSI_X923_Padding::add_padding(secure_vector<byte>& buffer,
+                                    size_t last_byte_pos,
+                                    size_t block_size) const
+   {
+   const byte pad_value = block_size - last_byte_pos;
+
+   for(size_t i = last_byte_pos; i < block_size; ++i)
+      buffer.push_back(0);
+   buffer.push_back(pad_value);
+   }
+
+/*
+* Unpad with ANSI X9.23 Method
+*/
+size_t ANSI_X923_Padding::unpad(const byte block[], size_t size) const
+   {
+   size_t position = block[size-1];
+   if(position > size)
+      throw Decoding_Error(name());
+   for(size_t j = size-position; j != size-1; ++j)
+      if(block[j] != 0)
+         throw Decoding_Error(name());
+   return (size-position);
+   }
+
+/*
+* Pad with One and Zeros Method
+*/
+void OneAndZeros_Padding::add_padding(secure_vector<byte>& buffer,
+                                      size_t last_byte_pos,
+                                      size_t block_size) const
+   {
+   buffer.push_back(0x80);
+
+   for(size_t i = last_byte_pos + 1; i % block_size; ++i)
+      buffer.push_back(0x00);
+   }
+
+/*
+* Unpad with One and Zeros Method
+*/
+size_t OneAndZeros_Padding::unpad(const byte block[], size_t size) const
+   {
+   while(size)
+      {
+      if(block[size-1] == 0x80)
+         break;
+      if(block[size-1] != 0x00)
+         throw Decoding_Error(name());
+      size--;
+      }
+   if(!size)
+      throw Decoding_Error(name());
+   return (size-1);
+   }
+
+
+}
diff --git a/src/lib/modes/mode_pad/mode_pad.h b/src/lib/modes/mode_pad/mode_pad.h
new file mode 100644
index 000000000..e7c38a196
--- /dev/null
+++ b/src/lib/modes/mode_pad/mode_pad.h
@@ -0,0 +1,124 @@
+/*
+* ECB/CBC Padding Methods
+* (C) 1999-2008,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_MODE_PADDING_H__
+#define BOTAN_MODE_PADDING_H__
+
+#include <botan/secmem.h>
+#include <string>
+
+namespace Botan {
+
+/**
+* Block Cipher Mode Padding Method
+* This class is pretty limited, it cannot deal well with
+* randomized padding methods, or any padding method that
+* wants to add more than one block. For instance, it should
+* be possible to define cipher text stealing mode as simply
+* a padding mode for CBC, which happens to consume the last
+* two block (and requires use of the block cipher).
+*/
+class BOTAN_DLL BlockCipherModePaddingMethod
+   {
+   public:
+      virtual void add_padding(secure_vector<byte>& buffer,
+                               size_t final_block_bytes,
+                               size_t block_size) const = 0;
+
+      /**
+      * @param block the last block
+      * @param size the of the block
+      */
+      virtual size_t unpad(const byte block[],
+                           size_t size) const = 0;
+
+      /**
+      * @param block_size of the cipher
+      * @return valid block size for this padding mode
+      */
+      virtual bool valid_blocksize(size_t block_size) const = 0;
+
+      /**
+      * @return name of the mode
+      */
+      virtual std::string name() const = 0;
+
+      /**
+      * virtual destructor
+      */
+      virtual ~BlockCipherModePaddingMethod() {}
+   };
+
+/**
+* PKCS#7 Padding
+*/
+class BOTAN_DLL PKCS7_Padding : public BlockCipherModePaddingMethod
+   {
+   public:
+      void add_padding(secure_vector<byte>& buffer,
+                       size_t final_block_bytes,
+                       size_t block_size) const override;
+
+      size_t unpad(const byte[], size_t) const;
+
+      bool valid_blocksize(size_t bs) const { return (bs > 0 && bs < 256); }
+
+      std::string name() const { return "PKCS7"; }
+   };
+
+/**
+* ANSI X9.23 Padding
+*/
+class BOTAN_DLL ANSI_X923_Padding : public BlockCipherModePaddingMethod
+   {
+   public:
+      void add_padding(secure_vector<byte>& buffer,
+                       size_t final_block_bytes,
+                       size_t block_size) const override;
+
+      size_t unpad(const byte[], size_t) const;
+
+      bool valid_blocksize(size_t bs) const { return (bs > 0 && bs < 256); }
+
+      std::string name() const { return "X9.23"; }
+   };
+
+/**
+* One And Zeros Padding
+*/
+class BOTAN_DLL OneAndZeros_Padding : public BlockCipherModePaddingMethod
+   {
+   public:
+      void add_padding(secure_vector<byte>& buffer,
+                       size_t final_block_bytes,
+                       size_t block_size) const override;
+
+      size_t unpad(const byte[], size_t) const;
+
+      bool valid_blocksize(size_t bs) const { return (bs > 0); }
+
+      std::string name() const { return "OneAndZeros"; }
+   };
+
+/**
+* Null Padding
+*/
+class BOTAN_DLL Null_Padding : public BlockCipherModePaddingMethod
+   {
+   public:
+      void add_padding(secure_vector<byte>&, size_t, size_t) const override {}
+
+      size_t unpad(const byte[], size_t size) const { return size; }
+
+      bool valid_blocksize(size_t) const { return true; }
+
+      std::string name() const { return "NoPadding"; }
+   };
+
+}
+
+#endif
diff --git a/src/lib/modes/xts/info.txt b/src/lib/modes/xts/info.txt
new file mode 100644
index 000000000..5f5dc7834
--- /dev/null
+++ b/src/lib/modes/xts/info.txt
@@ -0,0 +1 @@
+define MODE_XTS 20131128
diff --git a/src/lib/modes/xts/xts.cpp b/src/lib/modes/xts/xts.cpp
new file mode 100644
index 000000000..02da5fa5d
--- /dev/null
+++ b/src/lib/modes/xts/xts.cpp
@@ -0,0 +1,285 @@
+/*
+* 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;
+      }
+   }
+
+}
diff --git a/src/lib/modes/xts/xts.h b/src/lib/modes/xts/xts.h
new file mode 100644
index 000000000..21bc495e1
--- /dev/null
+++ b/src/lib/modes/xts/xts.h
@@ -0,0 +1,86 @@
+/*
+* XTS mode, from IEEE P1619
+* (C) 2009,2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_MODE_XTS_H__
+#define BOTAN_MODE_XTS_H__
+
+#include <botan/cipher_mode.h>
+#include <botan/block_cipher.h>
+#include <memory>
+
+namespace Botan {
+
+/**
+* IEEE P1619 XTS Mode
+*/
+class BOTAN_DLL XTS_Mode : public Cipher_Mode
+   {
+   public:
+      std::string name() const override;
+
+      secure_vector<byte> start(const byte nonce[], size_t nonce_len) override;
+
+      size_t update_granularity() const override;
+
+      size_t minimum_final_size() const override;
+
+      Key_Length_Specification key_spec() const override;
+
+      size_t default_nonce_length() const override;
+
+      bool valid_nonce_length(size_t n) const override;
+
+      void clear();
+   protected:
+      XTS_Mode(BlockCipher* cipher);
+
+      const byte* tweak() const { return &m_tweak[0]; }
+
+      const BlockCipher& cipher() const { return *m_cipher; }
+
+      void update_tweak(size_t last_used);
+
+   private:
+      void key_schedule(const byte key[], size_t length) override;
+
+      std::unique_ptr<BlockCipher> m_cipher, m_tweak_cipher;
+      secure_vector<byte> m_tweak;
+   };
+
+/**
+* IEEE P1619 XTS Encryption
+*/
+class BOTAN_DLL XTS_Encryption : public XTS_Mode
+   {
+   public:
+      XTS_Encryption(BlockCipher* cipher) : XTS_Mode(cipher) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override;
+   };
+
+/**
+* IEEE P1619 XTS Decryption
+*/
+class BOTAN_DLL XTS_Decryption : public XTS_Mode
+   {
+   public:
+      XTS_Decryption(BlockCipher* cipher) : XTS_Mode(cipher) {}
+
+      void update(secure_vector<byte>& blocks, size_t offset = 0) override;
+
+      void finish(secure_vector<byte>& final_block, size_t offset = 0) override;
+
+      size_t output_length(size_t input_length) const override;
+   };
+
+}
+
+#endif