Add XTS mode, from IEEE P1619

6 files changed, 818 insertions, 1 deletions

diff --git a/checks/algos.cpp b/checks/algos.cpp
index 79a609dda..d106d1479 100644
--- a/checks/algos.cpp
+++ b/checks/algos.cpp
@@ -24,7 +24,7 @@ std::vector<algorithm> get_algos()
    algos.push_back(algorithm("Block Cipher", "KASUMI", "KASUMI/ECB", 16));
 
    algos.push_back(algorithm("Block Cipher",
-                             "Lion(SHA-256,Turing)",
+                             "Lion",
                              "Lion(SHA-256,Turing,8192)/ECB", 32));
 
    algos.push_back(algorithm("Block Cipher", "Luby-Rackoff(SHA-512)",
@@ -61,6 +61,7 @@ std::vector<algorithm> get_algos()
    algos.push_back(algorithm("Cipher Mode", "AES-128/CTR",
                              "AES-128/CTR-BE", 16, 16));
    algos.push_back(algorithm("Cipher Mode", "AES-128/EAX", 16, 16));
+   algos.push_back(algorithm("Cipher Mode", "AES-128/XTS", 32, 16));
 
    algos.push_back(algorithm("Stream Cipher", "ARC4", 16));
    algos.push_back(algorithm("Stream Cipher", "Salsa20", 32));
diff --git a/checks/validate.dat b/checks/validate.dat
index eaa288b15..652c5b2ee 100644
--- a/checks/validate.dat
+++ b/checks/validate.dat
@@ -23888,6 +23888,332 @@ C61A0851AB4E515D11525B92E2B9D850:C825FC7C4D539DC74887CECC70884F37
 60:710DABD24D400F3B6B:\
 F956B879EC7F807F1FCB482B53623671:E64F90B4619D93137E6237929EABF297
 
+[AES/XTS]
+# Vectors are from IEEE P1619 D11
+
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+9A785634120000000000000000000000
+
+000102030405060708090A0B0C0D0E0F1011:\
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+
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+
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+9A785634120000000000000000000000
+
+000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F\
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+E0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFF0F1F2F3F4F5F6F7F8F9FAFBFCFDFEFF:\
+38B45812EF43A05BD957E545907E223B954AB4AAF088303AD910EADF14B42BE6\
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+8B7A4E1E7F0B2C04830E69A4FD1378411C2F287EDF48C6C4E5C247A19680F7FE\
+41CEFBD49B582106E3616CBBE4DFB2344B2AE9519391F3E0FB4922254B1D6D2D\
+19C6D4D537B3A26F3BCC51588B32F3ECA0829B6A5AC72578FB814FB43CF80D64\
+A233E3F997A3F02683342F2B33D25B492536B93BECB2F5E1A8B82F5B88334272\
+9E8AE09D16938841A21A97FB543EEA3BBFF59F13C1A18449E398701C1AD51648\
+346CBC04C27BB2DA3B93A1372CCAE548FB53BEE476F9E9C91773B1BB19828394\
+D55D3E1A20ED69113A860B6829FFA847224604435070221B257E8DFF783615D2\
+CAE4803A93AA4334AB482A0AFAC9C0AEDA70B45A481DF5DEC5DF8CC0F423C77A\
+5FD46CD312021D4B438862419A791BE03BB4D97C0E59578542531BA466A83BAF\
+92CEFC151B5CC1611A167893819B63FB8A6B18E86DE60290FA72B797B0CE59F3:\
+E0E1E2E3E4E5E6E7E8E9EAEBECEDEEEFC0C1C2C3C4C5C6C7C8C9CACBCCCDCECF:\
+21436587A90000000000000000000000
+
+# Generated by Botan
+
+000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E:\
+D05BC090A8E04F1B3D3ECDD5BAEC0FD4EDBF9DACE45D6F6A7306E64BE5DD82:\
+FFFEFDFCFBFAF9F8F7F6F5F4F3F2F1F0BFBEBDBCBBBAB9B8B7B6B5B4B3B2B1B0:\
+9A785634120000000000000000000000
+
 # MARKER: Cipher Modes (Decryption)
 
 # Cipher mode format is plaintext:ciphertext:key:iv
@@ -24891,6 +25217,47 @@ C61A0851AB4E515D11525B92E2B9D850:C825FC7C4D539DC74887CECC70884F37
 710DABD24D400F3B6B:60:\
 F956B879EC7F807F1FCB482B53623671:E64F90B4619D93137E6237929EABF297
 
+[AES/XTS]
+917CF69EBD68B2EC9B9FE9A3EADDA692CD43D2F59598ED858C02C2652FBF922E:\
+0000000000000000000000000000000000000000000000000000000000000000:\
+0000000000000000000000000000000000000000000000000000000000000000:\
+00000000000000000000000000000000
+
+C454185E6A16936E39334038ACEF838BFB186FFF7480ADC4289382ECD6D394F0:\
+4444444444444444444444444444444444444444444444444444444444444444:\
+1111111111111111111111111111111122222222222222222222222222222222:\
+33333333330000000000000000000000
+
+B01F86F8EDC1863706FA8A4253E34F28AF319DE38334870F4DD1F94CBE9832F1:\
+4444444444444444444444444444444444444444444444444444444444444444:\
+FFFEFDFCFBFAF9F8F7F6F5F4F3F2F1F0BFBEBDBCBBBAB9B8B7B6B5B4B3B2B1B0:\
+9A785634120000000000000000000000
+
+6C1625DB4671522D3D7599601DE7CA09ED:\
+000102030405060708090A0B0C0D0E0F10:\
+FFFEFDFCFBFAF9F8F7F6F5F4F3F2F1F0BFBEBDBCBBBAB9B8B7B6B5B4B3B2B1B0:\
+9A785634120000000000000000000000
+
+D069444B7A7E0CAB09E24447D24DEB1FEDBF:\
+000102030405060708090A0B0C0D0E0F1011:\
+FFFEFDFCFBFAF9F8F7F6F5F4F3F2F1F0BFBEBDBCBBBAB9B8B7B6B5B4B3B2B1B0:\
+9A785634120000000000000000000000
+
+E5DF1351C0544BA1350B3363CD8EF4BEEDBF9D:\
+000102030405060708090A0B0C0D0E0F101112:\
+FFFEFDFCFBFAF9F8F7F6F5F4F3F2F1F0BFBEBDBCBBBAB9B8B7B6B5B4B3B2B1B0:\
+9A785634120000000000000000000000
+
+9D84C813F719AA2C7BE3F66171C7C5C2EDBF9DAC:\
+000102030405060708090A0B0C0D0E0F10111213:\
+FFFEFDFCFBFAF9F8F7F6F5F4F3F2F1F0BFBEBDBCBBBAB9B8B7B6B5B4B3B2B1B0:\
+9A785634120000000000000000000000
+
+D05BC090A8E04F1B3D3ECDD5BAEC0FD4EDBF9DACE45D6F6A7306E64BE5DD82:\
+000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E:\
+FFFEFDFCFBFAF9F8F7F6F5F4F3F2F1F0BFBEBDBCBBBAB9B8B7B6B5B4B3B2B1B0:\
+9A785634120000000000000000000000
+
 # MARKER: Stream Ciphers
 
 # Stream cipher format is plaintext:ciphertext:key
diff --git a/src/engine/def_engine/def_mode.cpp b/src/engine/def_engine/def_mode.cpp
index a61683f93..2b093a0a3 100644
--- a/src/engine/def_engine/def_mode.cpp
+++ b/src/engine/def_engine/def_mode.cpp
@@ -40,6 +40,10 @@
   #include <botan/eax.h>
 #endif
 
+#if defined(BOTAN_HAS_XTS)
+  #include <botan/xts.h>
+#endif
+
 namespace Botan {
 
 namespace {
@@ -188,6 +192,16 @@ Keyed_Filter* Default_Engine::get_cipher(const std::string& algo_spec,
       }
 #endif
 
+#if defined(BOTAN_HAS_XTS)
+   if(mode == "XTS")
+      {
+      if(direction == ENCRYPTION)
+         return new XTS_Encryption(block_cipher->clone());
+      else
+         return new XTS_Decryption(block_cipher->clone());
+      }
+#endif
+
    throw Algorithm_Not_Found("get_mode: " + cipher_name + "/" +
                              mode + "/" + padding);
    }
diff --git a/src/modes/xts/info.txt b/src/modes/xts/info.txt
new file mode 100644
index 000000000..30d8f3496
--- /dev/null
+++ b/src/modes/xts/info.txt
@@ -0,0 +1,15 @@
+realname "XTS block cipher mode"
+
+define XTS
+
+load_on auto
+
+<add>
+xts.cpp
+xts.h
+</add>
+
+<requires>
+modes
+</requires>
+
diff --git a/src/modes/xts/xts.cpp b/src/modes/xts/xts.cpp
new file mode 100644
index 000000000..8819c85dc
--- /dev/null
+++ b/src/modes/xts/xts.cpp
@@ -0,0 +1,344 @@
+/*
+* XTS Mode
+* (C) 2009 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/xts.h>
+#include <botan/xor_buf.h>
+#include <algorithm>
+#include <stdexcept>
+
+namespace Botan {
+
+namespace {
+
+void poly_double(byte tweak[], u32bit size)
+   {
+   const byte polynomial = 0x87; // for 128 bit ciphers
+
+   byte carry = 0;
+   for(u32bit i = 0; i != size; ++i)
+      {
+      byte carry2 = (tweak[i] >> 7);
+      tweak[i] = (tweak[i] << 1) | carry;
+      carry = carry2;
+      }
+
+   if(carry)
+      tweak[0] ^= polynomial;
+   }
+
+}
+
+/*
+* XTS_Encryption constructor
+*/
+XTS_Encryption::XTS_Encryption(BlockCipher* ciph) : cipher(ciph)
+   {
+   if(cipher->BLOCK_SIZE != 16)
+      throw std::invalid_argument("Bad cipher for XTS: " + cipher->name());
+
+   cipher2 = cipher->clone();
+   buffer.create(cipher->BLOCK_SIZE);
+   tweak.create(cipher->BLOCK_SIZE);
+   buffer.create(2 * cipher->BLOCK_SIZE);
+   position = 0;
+   }
+
+/*
+* XTS_Encryption constructor
+*/
+XTS_Encryption::XTS_Encryption(BlockCipher* ciph,
+                               const SymmetricKey& key,
+                               const InitializationVector& iv) : cipher(ciph)
+   {
+   if(cipher->BLOCK_SIZE != 16)
+      throw std::invalid_argument("Bad cipher for XTS: " + cipher->name());
+
+   cipher2 = cipher->clone();
+   buffer.create(cipher->BLOCK_SIZE);
+   tweak.create(cipher->BLOCK_SIZE);
+   buffer.create(2 * cipher->BLOCK_SIZE);
+   position = 0;
+
+   set_key(key);
+   set_iv(iv);
+   }
+
+/*
+* Return the name
+*/
+std::string XTS_Encryption::name() const
+   {
+   return (cipher->name() + "/XTS");
+   }
+
+/*
+* Set new tweak
+*/
+void XTS_Encryption::set_iv(const InitializationVector& iv)
+   {
+   if(iv.length() != tweak.size())
+      throw Invalid_IV_Length(name(), iv.length());
+
+   tweak = iv.bits_of();
+   cipher2->encrypt(tweak);
+   }
+
+void XTS_Encryption::set_key(const SymmetricKey& key)
+   {
+   u32bit key_half = key.length() / 2;
+
+   if(key.length() % 2 == 1 || !cipher->valid_keylength(key_half))
+      throw Invalid_Key_Length(name(), key.length());
+
+   cipher->set_key(key.begin(), key_half);
+   cipher2->set_key(key.begin() + key_half, key_half);
+   }
+
+void XTS_Encryption::encrypt(const byte block[])
+   {
+   /*
+   * We can always use the first 16 bytes of buffer as temp space,
+   * since either the input block is buffer (in which case this is
+   * just buffer ^= tweak) or it not, in which case we already read
+   * and used the data there and are processing new input. Kind of
+   * subtle/nasty, but saves allocating a distinct temp buf.
+   */
+
+   xor_buf(buffer, block, tweak, cipher->BLOCK_SIZE);
+   cipher->encrypt(buffer);
+   xor_buf(buffer, tweak, cipher->BLOCK_SIZE);
+
+   poly_double(tweak, cipher->BLOCK_SIZE);
+
+   send(buffer, cipher->BLOCK_SIZE);
+   }
+
+/*
+* Encrypt in XTS mode
+*/
+void XTS_Encryption::write(const byte input[], u32bit length)
+   {
+   const u32bit BLOCK_SIZE = cipher->BLOCK_SIZE;
+
+   u32bit copied = std::min(buffer.size() - position, length);
+   buffer.copy(position, input, copied);
+   length -= copied;
+   input += copied;
+   position += copied;
+
+   if(length == 0) return;
+
+   encrypt(buffer);
+   if(length > BLOCK_SIZE)
+      {
+      encrypt(buffer + BLOCK_SIZE);
+      while(length > buffer.size())
+         {
+         encrypt(input);
+         length -= BLOCK_SIZE;
+         input += BLOCK_SIZE;
+         }
+      position = 0;
+      }
+   else
+      {
+      copy_mem(buffer.begin(), buffer + BLOCK_SIZE, BLOCK_SIZE);
+      position = BLOCK_SIZE;
+      }
+   buffer.copy(position, input, length);
+   position += length;
+   }
+
+/*
+* Finish encrypting in XTS mode
+*/
+void XTS_Encryption::end_msg()
+   {
+   const u32bit BLOCK_SIZE = cipher->BLOCK_SIZE;
+
+   if(position < BLOCK_SIZE)
+      throw Exception("XTS_Encryption: insufficient data to encrypt");
+   else if(position == BLOCK_SIZE)
+      {
+      encrypt(buffer);
+      }
+   else if(position == 2*BLOCK_SIZE)
+      {
+      encrypt(buffer);
+      encrypt(buffer + BLOCK_SIZE);
+      }
+   else
+      { // steal ciphertext
+      xor_buf(buffer, tweak, cipher->BLOCK_SIZE);
+      cipher->encrypt(buffer);
+      xor_buf(buffer, tweak, cipher->BLOCK_SIZE);
+
+      poly_double(tweak, cipher->BLOCK_SIZE);
+
+      for(u32bit i = 0; i != position - cipher->BLOCK_SIZE; ++i)
+         std::swap(buffer[i], buffer[i + cipher->BLOCK_SIZE]);
+
+      xor_buf(buffer, tweak, cipher->BLOCK_SIZE);
+      cipher->encrypt(buffer);
+      xor_buf(buffer, tweak, cipher->BLOCK_SIZE);
+
+      send(buffer, position);
+      }
+   }
+
+/*
+* XTS_Decryption constructor
+*/
+XTS_Decryption::XTS_Decryption(BlockCipher* ciph)
+   {
+   cipher = ciph;
+   cipher2 = ciph->clone();
+   buffer.create(cipher->BLOCK_SIZE);
+   tweak.create(cipher->BLOCK_SIZE);
+   buffer.create(2 * cipher->BLOCK_SIZE);
+   position = 0;
+   }
+
+/*
+* XTS_Decryption constructor
+*/
+XTS_Decryption::XTS_Decryption(BlockCipher* ciph,
+                               const SymmetricKey& key,
+                               const InitializationVector& iv)
+   {
+   cipher = ciph;
+   cipher2 = ciph->clone();
+   buffer.create(cipher->BLOCK_SIZE);
+   tweak.create(cipher->BLOCK_SIZE);
+   buffer.create(2 * cipher->BLOCK_SIZE);
+   position = 0;
+
+   set_key(key);
+   set_iv(iv);
+   }
+
+/*
+* Return the name
+*/
+std::string XTS_Decryption::name() const
+   {
+   return (cipher->name() + "/XTS");
+   }
+
+/*
+* Set new tweak
+*/
+void XTS_Decryption::set_iv(const InitializationVector& iv)
+   {
+   if(iv.length() != tweak.size())
+      throw Invalid_IV_Length(name(), iv.length());
+
+   tweak = iv.bits_of();
+   cipher2->encrypt(tweak);
+   }
+
+void XTS_Decryption::set_key(const SymmetricKey& key)
+   {
+   u32bit key_half = key.length() / 2;
+
+   if(key.length() % 2 == 1 || !cipher->valid_keylength(key_half))
+      throw Invalid_Key_Length(name(), key.length());
+
+   cipher->set_key(key.begin(), key_half);
+   cipher2->set_key(key.begin() + key_half, key_half);
+   }
+
+/*
+* Decrypt a block
+*/
+void XTS_Decryption::decrypt(const byte block[])
+   {
+   xor_buf(buffer, block, tweak, cipher->BLOCK_SIZE);
+   cipher->decrypt(buffer);
+   xor_buf(buffer, tweak, cipher->BLOCK_SIZE);
+
+   poly_double(tweak, cipher->BLOCK_SIZE);
+
+   send(buffer, cipher->BLOCK_SIZE);
+   }
+
+/*
+* Decrypt in XTS mode
+*/
+void XTS_Decryption::write(const byte input[], u32bit length)
+   {
+   const u32bit BLOCK_SIZE = cipher->BLOCK_SIZE;
+
+   u32bit copied = std::min(buffer.size() - position, length);
+   buffer.copy(position, input, copied);
+   length -= copied;
+   input += copied;
+   position += copied;
+
+   if(length == 0) return;
+
+   decrypt(buffer);
+   if(length > BLOCK_SIZE)
+      {
+      decrypt(buffer + BLOCK_SIZE);
+      while(length > 2*BLOCK_SIZE)
+         {
+         decrypt(input);
+         length -= BLOCK_SIZE;
+         input += BLOCK_SIZE;
+         }
+      position = 0;
+      }
+   else
+      {
+      copy_mem(buffer.begin(), buffer + BLOCK_SIZE, BLOCK_SIZE);
+      position = BLOCK_SIZE;
+      }
+   buffer.copy(position, input, length);
+   position += length;
+   }
+
+/*
+* Finish decrypting in XTS mode
+*/
+void XTS_Decryption::end_msg()
+   {
+   const u32bit BLOCK_SIZE = cipher->BLOCK_SIZE;
+
+   if(position < BLOCK_SIZE)
+      throw Exception("XTS_Decryption: insufficient data to decrypt");
+   else if(position == BLOCK_SIZE)
+      {
+      decrypt(buffer);
+      }
+   else if(position == 2*BLOCK_SIZE)
+      {
+      decrypt(buffer);
+      decrypt(buffer + BLOCK_SIZE);
+      }
+   else
+      {
+      SecureVector<byte> tweak2 = tweak;
+
+      poly_double(tweak2, cipher->BLOCK_SIZE);
+
+      xor_buf(buffer, tweak2, cipher->BLOCK_SIZE);
+      cipher->decrypt(buffer);
+      xor_buf(buffer, tweak2, cipher->BLOCK_SIZE);
+
+      for(u32bit i = 0; i != position - cipher->BLOCK_SIZE; ++i)
+         std::swap(buffer[i], buffer[i + cipher->BLOCK_SIZE]);
+
+      xor_buf(buffer, tweak, cipher->BLOCK_SIZE);
+      cipher->decrypt(buffer);
+      xor_buf(buffer, tweak, cipher->BLOCK_SIZE);
+
+      send(buffer, position);
+      }
+   }
+
+}
diff --git a/src/modes/xts/xts.h b/src/modes/xts/xts.h
new file mode 100644
index 000000000..01558175b
--- /dev/null
+++ b/src/modes/xts/xts.h
@@ -0,0 +1,76 @@
+/*
+* XTS mode, from IEEE P1619
+* (C) 2009 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_XTS_H__
+#define BOTAN_XTS_H__
+
+#include <botan/basefilt.h>
+#include <botan/block_cipher.h>
+
+namespace Botan {
+
+/*
+* XTS Encryption
+*/
+class BOTAN_DLL XTS_Encryption : public Keyed_Filter
+   {
+   public:
+      void set_key(const SymmetricKey& key);
+      void set_iv(const InitializationVector& iv);
+
+      std::string name() const;
+
+      XTS_Encryption(BlockCipher* ciph);
+
+      XTS_Encryption(BlockCipher* ciph,
+                     const SymmetricKey& key,
+                     const InitializationVector& iv);
+
+      ~XTS_Encryption() { delete cipher; delete cipher2; }
+   private:
+      void write(const byte[], u32bit);
+      void end_msg();
+      void encrypt(const byte block[]);
+
+      BlockCipher* cipher;
+      BlockCipher* cipher2;
+      SecureVector<byte> tweak;
+      SecureVector<byte> buffer;
+      u32bit position;
+   };
+
+/*
+* XTS Decryption
+*/
+class BOTAN_DLL XTS_Decryption : public Keyed_Filter
+   {
+   public:
+      void set_key(const SymmetricKey& key);
+      void set_iv(const InitializationVector& iv);
+
+      std::string name() const;
+
+      XTS_Decryption(BlockCipher* ciph);
+
+      XTS_Decryption(BlockCipher* ciph,
+                     const SymmetricKey& key,
+                     const InitializationVector& iv);
+   private:
+      void write(const byte[], u32bit);
+      void end_msg();
+      void decrypt(const byte[]);
+
+      BlockCipher* cipher;
+      BlockCipher* cipher2;
+      SecureVector<byte> tweak;
+      SecureVector<byte> buffer;
+      u32bit position;
+   };
+
+}
+
+#endif