4 files changed, 179 insertions, 0 deletions
diff --git a/src/lib/engine/core_engine/lookup_mac.cpp b/src/lib/engine/core_engine/lookup_mac.cpp
index ba5cd69c6..d5e16cf44 100644
--- a/src/lib/engine/core_engine/lookup_mac.cpp
+++ b/src/lib/engine/core_engine/lookup_mac.cpp
@@ -25,6 +25,10 @@
   #include <botan/poly1305.h>
 #endif
 
+#if defined(BOTAN_HAS_SIPHASH)
+  #include <botan/siphash.h>
+#endif
+
 #if defined(BOTAN_HAS_ANSI_X919_MAC)
   #include <botan/x919_mac.h>
 #endif
@@ -53,6 +57,12 @@ Core_Engine::find_mac(const SCAN_Name& request,
       return new Poly1305;
 #endif
 
+#if defined(BOTAN_HAS_SIPHASH)
+   if(request.algo_name() == "SipHash")
+      return new SipHash(request.arg_as_integer(0, 2),
+                         request.arg_as_integer(1, 4));
+#endif
+
 #if defined(BOTAN_HAS_CBC_MAC)
    if(request.algo_name() == "CBC-MAC" && request.arg_count() == 1)
       return new CBC_MAC(af.make_block_cipher(request.arg(0)));
diff --git a/src/lib/mac/siphash/info.txt b/src/lib/mac/siphash/info.txt
new file mode 100644
index 000000000..98c4d0986
--- /dev/null
+++ b/src/lib/mac/siphash/info.txt
@@ -0,0 +1 @@
+define SIPHASH 20150110
diff --git a/src/lib/mac/siphash/siphash.cpp b/src/lib/mac/siphash/siphash.cpp
new file mode 100644
index 000000000..bc242d4ac
--- /dev/null
+++ b/src/lib/mac/siphash/siphash.cpp
@@ -0,0 +1,123 @@
+/*
+* SipHash
+* (C) 2014,2015 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/siphash.h>
+#include <botan/rotate.h>
+#include <botan/loadstor.h>
+#include <botan/internal/xor_buf.h>
+
+namespace Botan {
+
+namespace {
+
+void SipRounds(u64bit M, secure_vector<u64bit>& V, size_t r)
+   {
+   u64bit V0 = V[0], V1 = V[1], V2 = V[2], V3 = V[3];
+
+   V3 ^= M;
+   for(size_t i = 0; i != r; ++i)
+      {
+      V0 += V1; V2 += V3;
+      V1 = rotate_left(V1, 13);
+      V3 = rotate_left(V3, 16);
+      V1 ^= V0; V3 ^= V2;
+      V0 = rotate_left(V0, 32);
+
+      V2 += V1; V0 += V3;
+      V1 = rotate_left(V1, 17);
+      V3 = rotate_left(V3, 21);
+      V1 ^= V2; V3 ^= V0;
+      V2 = rotate_left(V2, 32);
+      }
+   V0 ^= M;
+
+   V[0] = V0; V[1] = V1; V[2] = V2; V[3] = V3;
+   }
+
+}
+
+void SipHash::add_data(const byte input[], size_t length)
+   {
+   m_words += length;
+
+   if(m_mbuf_pos)
+      {
+      while(length && m_mbuf_pos != 8)
+         {
+         m_mbuf = (m_mbuf >> 8) | (static_cast<u64bit>(input[0]) << 56);
+         ++m_mbuf_pos;
+         ++input;
+         length--;
+         }
+
+      if(m_mbuf_pos == 8)
+         {
+         SipRounds(m_mbuf, m_V, m_C);
+         m_mbuf_pos = 0;
+         m_mbuf = 0;
+         }
+      }
+
+   while(length >= 8)
+      {
+      SipRounds(load_le<u64bit>(input, 0), m_V, m_C);
+      input += 8;
+      length -= 8;
+      }
+
+   for(size_t i = 0; i != length; ++i)
+      {
+      m_mbuf = (m_mbuf >> 8) | (static_cast<u64bit>(input[i]) << 56);
+      m_mbuf_pos++;
+      }
+   }
+
+void SipHash::final_result(byte mac[])
+   {
+   m_mbuf = (m_mbuf >> (64-m_mbuf_pos*8)) | (static_cast<u64bit>(m_words) << 56);
+   SipRounds(m_mbuf, m_V, m_C);
+
+   m_V[2] ^= 0xFF;
+   SipRounds(0, m_V, m_D);
+
+   const u64bit X = m_V[0] ^ m_V[1] ^ m_V[2] ^ m_V[3];
+
+   store_le(X, mac);
+
+   m_mbuf = 0;
+   m_mbuf_pos = 0;
+   m_words = 0;
+   }
+
+void SipHash::key_schedule(const byte key[], size_t)
+   {
+   const u64bit K0 = load_le<u64bit>(key, 0);
+   const u64bit K1 = load_le<u64bit>(key, 1);
+
+   m_V.resize(4);
+   m_V[0] = K0 ^ 0x736F6D6570736575;
+   m_V[1] = K1 ^ 0x646F72616E646F6D;
+   m_V[2] = K0 ^ 0x6C7967656E657261;
+   m_V[3] = K1 ^ 0x7465646279746573;
+   }
+
+void SipHash::clear()
+   {
+   m_V.clear();
+   }
+
+std::string SipHash::name() const
+   {
+   return "SipHash(" + std::to_string(m_C) + "," + std::to_string(m_D) + ")";
+   }
+
+MessageAuthenticationCode* SipHash::clone() const
+   {
+   return new SipHash(m_C, m_D);
+   }
+
+}
diff --git a/src/lib/mac/siphash/siphash.h b/src/lib/mac/siphash/siphash.h
new file mode 100644
index 000000000..ec57864eb
--- /dev/null
+++ b/src/lib/mac/siphash/siphash.h
@@ -0,0 +1,45 @@
+/*
+* SipHash
+* (C) 2014,2015 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_SIPHASH_H__
+#define BOTAN_SIPHASH_H__
+
+#include <botan/mac.h>
+
+namespace Botan {
+
+class BOTAN_DLL SipHash : public MessageAuthenticationCode
+   {
+   public:
+      SipHash(size_t c = 2, size_t d = 4) : m_C(c), m_D(d) {}
+
+      void clear();
+      std::string name() const;
+
+      MessageAuthenticationCode* clone() const;
+
+      size_t output_length() const { return 8; }
+
+      Key_Length_Specification key_spec() const
+         {
+         return Key_Length_Specification(16);
+         }
+   private:
+      void add_data(const byte[], size_t);
+      void final_result(byte[]);
+      void key_schedule(const byte[], size_t);
+
+      const size_t m_C, m_D;
+      secure_vector<u64bit> m_V;
+      u64bit m_mbuf = 0;
+      size_t m_mbuf_pos = 0;
+      byte m_words = 0;
+   };
+
+}
+
+#endif