Add SHAKE-128 and SHAKE-256 as hash functions

10 files changed, 290 insertions, 86 deletions

diff --git a/src/lib/hash/hash.cpp b/src/lib/hash/hash.cpp
index ede2f8c99..112554127 100644
--- a/src/lib/hash/hash.cpp
+++ b/src/lib/hash/hash.cpp
@@ -56,6 +56,10 @@
   #include <botan/sha3.h>
 #endif
 
+#if defined(BOTAN_HAS_SHAKE)
+  #include <botan/shake.h>
+#endif
+
 #if defined(BOTAN_HAS_SKEIN_512)
   #include <botan/skein_512.h>
 #endif
@@ -242,6 +246,17 @@ std::unique_ptr<HashFunction> HashFunction::create(const std::string& algo_spec,
       }
 #endif
 
+#if defined(BOTAN_HAS_SHAKE)
+   if(req.algo_name() == "SHAKE-128")
+      {
+      return std::unique_ptr<HashFunction>(new SHAKE_128(req.arg_as_integer(0, 128)));
+      }
+   if(req.algo_name() == "SHAKE-256")
+      {
+      return std::unique_ptr<HashFunction>(new SHAKE_256(req.arg_as_integer(0, 256)));
+      }
+#endif
+
 #if defined(BOTAN_HAS_WHIRLPOOL)
    if(req.algo_name() == "Whirlpool")
       {
diff --git a/src/lib/hash/keccak/keccak.cpp b/src/lib/hash/keccak/keccak.cpp
index 60cb20696..e0c67131b 100644
--- a/src/lib/hash/keccak/keccak.cpp
+++ b/src/lib/hash/keccak/keccak.cpp
@@ -44,47 +44,7 @@ void Keccak_1600::clear()
 
 void Keccak_1600::add_data(const byte input[], size_t length)
    {
-   if(length == 0)
-      return;
-
-   while(length)
-      {
-      size_t to_take = std::min(length, m_bitrate / 8 - m_S_pos);
-
-      length -= to_take;
-
-      while(to_take && m_S_pos % 8)
-         {
-         m_S[m_S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (m_S_pos % 8));
-
-         ++m_S_pos;
-         ++input;
-         --to_take;
-         }
-
-      while(to_take && to_take % 8 == 0)
-         {
-         m_S[m_S_pos / 8] ^= load_le<u64bit>(input, 0);
-         m_S_pos += 8;
-         input += 8;
-         to_take -= 8;
-         }
-
-      while(to_take)
-         {
-         m_S[m_S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (m_S_pos % 8));
-
-         ++m_S_pos;
-         ++input;
-         --to_take;
-         }
-
-      if(m_S_pos == m_bitrate / 8)
-         {
-         SHA_3::permute(m_S.data());
-         m_S_pos = 0;
-         }
-      }
+   m_S_pos = SHA_3::absorb(m_bitrate, m_S, m_S_pos, input, length);
    }
 
 void Keccak_1600::final_result(byte output[])
diff --git a/src/lib/hash/sha3/sha3.cpp b/src/lib/hash/sha3/sha3.cpp
index 3897f0588..2361d7d5b 100644
--- a/src/lib/hash/sha3/sha3.cpp
+++ b/src/lib/hash/sha3/sha3.cpp
@@ -109,16 +109,6 @@ SHA_3::SHA_3(size_t output_bits) :
                              std::to_string(output_bits));
    }
 
-SHA_3::SHA_3(size_t output_bits, size_t capacity) :
-   m_output_bits(output_bits),
-   m_bitrate(1600 - capacity),
-   m_S(25),
-   m_S_pos(0)
-   {
-   if(capacity == 0 || capacity >= 1600)
-      throw Invalid_Argument("Impossible SHA-3 capacity specified");
-   }
-
 std::string SHA_3::name() const
    {
    return "SHA-3(" + std::to_string(m_output_bits) + ")";
@@ -135,49 +125,84 @@ void SHA_3::clear()
    m_S_pos = 0;
    }
 
-void SHA_3::add_data(const byte input[], size_t length)
+//static
+size_t SHA_3::absorb(size_t bitrate,
+                     secure_vector<uint64_t>& S, size_t S_pos,
+                     const byte input[], size_t length)
    {
-   if(length == 0)
-      return;
-
-   while(length)
+   while(length > 0)
       {
-      size_t to_take = std::min(length, m_bitrate / 8 - m_S_pos);
+      size_t to_take = std::min(length, bitrate / 8 - S_pos);
 
       length -= to_take;
 
-      while(to_take && m_S_pos % 8)
+      while(to_take && S_pos % 8)
          {
-         m_S[m_S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (m_S_pos % 8));
+         S[S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (S_pos % 8));
 
-         ++m_S_pos;
+         ++S_pos;
          ++input;
          --to_take;
          }
 
       while(to_take && to_take % 8 == 0)
          {
-         m_S[m_S_pos / 8] ^= load_le<u64bit>(input, 0);
-         m_S_pos += 8;
+         S[S_pos / 8] ^= load_le<u64bit>(input, 0);
+         S_pos += 8;
          input += 8;
          to_take -= 8;
          }
 
       while(to_take)
          {
-         m_S[m_S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (m_S_pos % 8));
+         S[S_pos / 8] ^= static_cast<u64bit>(input[0]) << (8 * (S_pos % 8));
 
-         ++m_S_pos;
+         ++S_pos;
          ++input;
          --to_take;
          }
 
-      if(m_S_pos == m_bitrate / 8)
+      if(S_pos == bitrate / 8)
          {
-         SHA_3::permute(m_S.data());
-         m_S_pos = 0;
+         SHA_3::permute(S.data());
+         S_pos = 0;
          }
       }
+
+   return S_pos;
+   }
+
+//static
+void SHA_3::expand(size_t bitrate,
+                   secure_vector<uint64_t>& S,
+                   byte output[], size_t output_length)
+   {
+   BOTAN_ARG_CHECK(bitrate % 8 == 0);
+
+   size_t Si = 0;
+
+   for(size_t i = 0; i != output_length; ++i)
+      {
+      if(i > 0)
+         {
+         if(i % (bitrate / 8) == 0)
+            {
+            SHA_3::permute(S.data());
+            Si = 0;
+            }
+         else if(i % 8 == 0)
+            {
+            Si += 1;
+            }
+         }
+
+      output[i] = get_byte(7 - (i % 8), S[Si]);
+      }
+   }
+
+void SHA_3::add_data(const byte input[], size_t length)
+   {
+   m_S_pos = SHA_3::absorb(m_bitrate, m_S, m_S_pos, input, length);
    }
 
 void SHA_3::final_result(byte output[])
diff --git a/src/lib/hash/sha3/sha3.h b/src/lib/hash/sha3/sha3.h
index c877bd938..649aa12fd 100644
--- a/src/lib/hash/sha3/sha3.h
+++ b/src/lib/hash/sha3/sha3.h
@@ -27,14 +27,6 @@ class BOTAN_DLL SHA_3 : public HashFunction
       */
       SHA_3(size_t output_bits);
 
-      /**
-      * @param output_bits the size of the hash output; must be a
-      * multiple of 8 (ie, byte-wide outputs)
-      * @param capacity the capacity of the spong, normally always
-      * 2*output_bits with SHA-3.
-      */
-      SHA_3(size_t output_bits, size_t capacity);
-
       size_t hash_block_size() const override { return m_bitrate / 8; }
       size_t output_length() const override { return m_output_bits / 8; }
 
@@ -42,6 +34,31 @@ class BOTAN_DLL SHA_3 : public HashFunction
       std::string name() const override;
       void clear() override;
 
+      // Static functions for internal usage
+
+      /**
+      * Absorb data into the provided state
+      * @param bitrate the bitrate to absorb into the sponge
+      * @param S the sponge state
+      * @param S_pos where to begin absorbing into S
+      * @param input the input data
+      * @param length size of input in bytes
+      */
+      static size_t absorb(size_t bitrate,
+                           secure_vector<uint64_t>& S, size_t S_pos,
+                           const byte input[], size_t length);
+
+      /**
+      * Expand from provided state
+      * @param bitrate sponge parameter
+      * @param S the state
+      * @param output the output buffer
+      * @param output_length the size of output in bytes
+      */
+      static void expand(size_t bitrate,
+                         secure_vector<uint64_t>& S,
+                         byte output[], size_t output_length);
+
       /**
       * The bare Keccak-1600 permutation
       */
diff --git a/src/lib/hash/shake/info.txt b/src/lib/hash/shake/info.txt
new file mode 100644
index 000000000..f579383eb
--- /dev/null
+++ b/src/lib/hash/shake/info.txt
@@ -0,0 +1,5 @@
+define SHAKE 20161009
+
+<requires>
+sha3
+</requires>
diff --git a/src/lib/hash/shake/shake.cpp b/src/lib/hash/shake/shake.cpp
new file mode 100644
index 000000000..1ff6f1fd3
--- /dev/null
+++ b/src/lib/hash/shake/shake.cpp
@@ -0,0 +1,101 @@
+/*
+* SHAKE-128/256 as a hash
+* (C) 2016 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/shake.h>
+#include <botan/sha3.h>
+#include <botan/parsing.h>
+#include <botan/exceptn.h>
+
+namespace Botan {
+
+SHAKE_128::SHAKE_128(size_t output_bits) :
+   m_output_bits(output_bits), m_S(25), m_S_pos(0)
+   {
+   if(output_bits % 8 != 0)
+      throw Invalid_Argument("SHAKE_128: Invalid output length " +
+                             std::to_string(output_bits));
+   }
+
+std::string SHAKE_128::name() const
+   {
+   return "SHAKE-128(" + std::to_string(m_output_bits) + ")";
+   }
+
+HashFunction* SHAKE_128::clone() const
+   {
+   return new SHAKE_128(m_output_bits);
+   }
+
+void SHAKE_128::clear()
+   {
+   zeroise(m_S);
+   m_S_pos = 0;
+   }
+
+void SHAKE_128::add_data(const byte input[], size_t length)
+   {
+   m_S_pos = SHA_3::absorb(SHAKE_128_BITRATE, m_S, m_S_pos, input, length);
+   }
+
+void SHAKE_128::final_result(byte output[])
+   {
+   std::vector<byte> padding(SHAKE_128_BITRATE / 8 - m_S_pos);
+
+   padding[0] = 0x1F;
+   padding[padding.size()-1] |= 0x80;
+
+   add_data(padding.data(), padding.size());
+
+   SHA_3::expand(SHAKE_128_BITRATE, m_S, output, output_length());
+
+   clear();
+   }
+
+SHAKE_256::SHAKE_256(size_t output_bits) :
+   m_output_bits(output_bits), m_S(25), m_S_pos(0)
+   {
+   if(output_bits % 8 != 0)
+      throw Invalid_Argument("SHAKE_256: Invalid output length " +
+                             std::to_string(output_bits));
+   }
+
+std::string SHAKE_256::name() const
+   {
+   return "SHAKE-256(" + std::to_string(m_output_bits) + ")";
+   }
+
+HashFunction* SHAKE_256::clone() const
+   {
+   return new SHAKE_256(m_output_bits);
+   }
+
+void SHAKE_256::clear()
+   {
+   zeroise(m_S);
+   m_S_pos = 0;
+   }
+
+void SHAKE_256::add_data(const byte input[], size_t length)
+   {
+   m_S_pos = SHA_3::absorb(SHAKE_256_BITRATE, m_S, m_S_pos, input, length);
+   }
+
+void SHAKE_256::final_result(byte output[])
+   {
+   std::vector<byte> padding(SHAKE_256_BITRATE / 8 - m_S_pos);
+
+   padding[0] = 0x1F;
+   padding[padding.size()-1] |= 0x80;
+
+   add_data(padding.data(), padding.size());
+
+   SHA_3::expand(SHAKE_256_BITRATE, m_S, output, output_length());
+
+   clear();
+   }
+
+}
diff --git a/src/lib/hash/shake/shake.h b/src/lib/hash/shake/shake.h
new file mode 100644
index 000000000..96c171323
--- /dev/null
+++ b/src/lib/hash/shake/shake.h
@@ -0,0 +1,81 @@
+/*
+* SHAKE hash functions
+* (C) 2010,2016 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_SHAKE_HASH_H__
+#define BOTAN_SHAKE_HASH_H__
+
+#include <botan/hash.h>
+#include <botan/secmem.h>
+#include <string>
+
+namespace Botan {
+
+/**
+* SHAKE-128
+*/
+class BOTAN_DLL SHAKE_128 : public HashFunction
+   {
+   public:
+
+      /**
+      * @param output_bits the desired output size in bits
+      * must be a multiple of 8
+      */
+      SHAKE_128(size_t output_bits);
+
+      size_t hash_block_size() const override { return SHAKE_128_BITRATE / 8; }
+      size_t output_length() const override { return m_output_bits / 8; }
+
+      HashFunction* clone() const override;
+      std::string name() const override;
+      void clear() override;
+
+   private:
+      void add_data(const byte input[], size_t length) override;
+      void final_result(byte out[]) override;
+
+      static const size_t SHAKE_128_BITRATE = 1600 - 256;
+
+      size_t m_output_bits;
+      secure_vector<u64bit> m_S;
+      size_t m_S_pos;
+   };
+
+/**
+* SHAKE-256
+*/
+class BOTAN_DLL SHAKE_256 : public HashFunction
+   {
+   public:
+
+      /**
+      * @param output_bits the desired output size in bits
+      * must be a multiple of 8
+      */
+      SHAKE_256(size_t output_bits);
+
+      size_t hash_block_size() const override { return SHAKE_256_BITRATE / 8; }
+      size_t output_length() const override { return m_output_bits / 8; }
+
+      HashFunction* clone() const override;
+      std::string name() const override;
+      void clear() override;
+
+   private:
+      void add_data(const byte input[], size_t length) override;
+      void final_result(byte out[]) override;
+
+      static const size_t SHAKE_256_BITRATE = 1600 - 512;
+
+      size_t m_output_bits;
+      secure_vector<u64bit> m_S;
+      size_t m_S_pos;
+   };
+
+}
+
+#endif
diff --git a/src/lib/stream/shake_cipher/shake_cipher.cpp b/src/lib/stream/shake_cipher/shake_cipher.cpp
index 5701e7802..dc3c73299 100644
--- a/src/lib/stream/shake_cipher/shake_cipher.cpp
+++ b/src/lib/stream/shake_cipher/shake_cipher.cpp
@@ -11,13 +11,13 @@
 
 namespace Botan {
 
-SHAKE_128::SHAKE_128() :
+SHAKE_128_Cipher::SHAKE_128_Cipher() :
    m_state(25),
    m_buffer((1600 - 256) / 8),
    m_buf_pos(0)
    {}
 
-void SHAKE_128::cipher(const byte in[], byte out[], size_t length)
+void SHAKE_128_Cipher::cipher(const byte in[], byte out[], size_t length)
    {
    while(length >= m_buffer.size() - m_buf_pos)
       {
@@ -35,7 +35,7 @@ void SHAKE_128::cipher(const byte in[], byte out[], size_t length)
    m_buf_pos += length;
    }
 
-void SHAKE_128::key_schedule(const byte key[], size_t length)
+void SHAKE_128_Cipher::key_schedule(const byte key[], size_t length)
    {
    zeroise(m_state);
 
@@ -51,14 +51,14 @@ void SHAKE_128::key_schedule(const byte key[], size_t length)
    copy_out_le(m_buffer.data(), m_buffer.size(), m_state.data());
    }
 
-void SHAKE_128::clear()
+void SHAKE_128_Cipher::clear()
    {
    zeroise(m_state);
    zeroise(m_buffer);
    m_buf_pos = 0;
    }
 
-void SHAKE_128::set_iv(const byte[], size_t length)
+void SHAKE_128_Cipher::set_iv(const byte[], size_t length)
    {
    /*
    * This could be supported in some way (say, by treating iv as
@@ -68,8 +68,8 @@ void SHAKE_128::set_iv(const byte[], size_t length)
       throw Invalid_IV_Length(name(), length);
    }
 
-void SHAKE_128::seek(u64bit)
+void SHAKE_128_Cipher::seek(u64bit)
    {
-   throw Not_Implemented("SHAKE_128::seek");
+   throw Not_Implemented("SHAKE_128_Cipher::seek");
    }
 }
diff --git a/src/lib/stream/shake_cipher/shake_cipher.h b/src/lib/stream/shake_cipher/shake_cipher.h
index 57eda58a4..40915ecea 100644
--- a/src/lib/stream/shake_cipher/shake_cipher.h
+++ b/src/lib/stream/shake_cipher/shake_cipher.h
@@ -16,10 +16,10 @@ namespace Botan {
 /**
 * SHAKE-128 XOF presented as a stream cipher
 */
-class BOTAN_DLL SHAKE_128 final : public StreamCipher
+class BOTAN_DLL SHAKE_128_Cipher final : public StreamCipher
    {
    public:
-      SHAKE_128();
+      SHAKE_128_Cipher();
 
       /**
       * Produce more XOF output
@@ -49,7 +49,7 @@ class BOTAN_DLL SHAKE_128 final : public StreamCipher
 
       void clear() override;
       std::string name() const override { return "SHAKE-128"; }
-      StreamCipher* clone() const override { return new SHAKE_128; }
+      StreamCipher* clone() const override { return new SHAKE_128_Cipher; }
 
    private:
       void key_schedule(const byte key[], size_t key_len) override;
diff --git a/src/lib/stream/stream_cipher.cpp b/src/lib/stream/stream_cipher.cpp
index 4b27caafe..dfe1fa69b 100644
--- a/src/lib/stream/stream_cipher.cpp
+++ b/src/lib/stream/stream_cipher.cpp
@@ -74,7 +74,7 @@ std::unique_ptr<StreamCipher> StreamCipher::create(const std::string& algo_spec,
    if(req.algo_name() == "SHAKE-128")
       {
       if(provider.empty() || provider == "base")
-         return std::unique_ptr<StreamCipher>(new SHAKE_128);
+         return std::unique_ptr<StreamCipher>(new SHAKE_128_Cipher);
       }
 #endif