Coverage Report

Created: 2020-02-14 15:38

/src/botan/src/lib/mac/siphash/siphash.cpp
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Source (jump to first uncovered line)
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/*
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* SipHash
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* (C) 2014,2015 Jack Lloyd
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*
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* Botan is released under the Simplified BSD License (see license.txt)
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*/
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#include <botan/siphash.h>
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#include <botan/loadstor.h>
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#include <botan/rotate.h>
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namespace Botan {
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namespace {
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void SipRounds(uint64_t M, secure_vector<uint64_t>& V, size_t r)
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   {
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   uint64_t V0 = V[0], V1 = V[1], V2 = V[2], V3 = V[3];
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   V3 ^= M;
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   for(size_t i = 0; i != r; ++i)
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      {
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      V0 += V1; V2 += V3;
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      V1 = rotl<13>(V1);
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      V3 = rotl<16>(V3);
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      V1 ^= V0; V3 ^= V2;
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      V0 = rotl<32>(V0);
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      V2 += V1; V0 += V3;
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      V1 = rotl<17>(V1);
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      V3 = rotl<21>(V3);
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      V1 ^= V2; V3 ^= V0;
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      V2 = rotl<32>(V2);
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      }
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   V0 ^= M;
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   V[0] = V0; V[1] = V1; V[2] = V2; V[3] = V3;
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   }
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}
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void SipHash::add_data(const uint8_t input[], size_t length)
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   {
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   verify_key_set(m_V.empty() == false);
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   // SipHash counts the message length mod 256
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   m_words += static_cast<uint8_t>(length);
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   if(m_mbuf_pos)
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      {
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      while(length && m_mbuf_pos != 8)
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         {
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         m_mbuf = (m_mbuf >> 8) | (static_cast<uint64_t>(input[0]) << 56);
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         ++m_mbuf_pos;
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         ++input;
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         length--;
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         }
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      if(m_mbuf_pos == 8)
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         {
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         SipRounds(m_mbuf, m_V, m_C);
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         m_mbuf_pos = 0;
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         m_mbuf = 0;
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         }
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      }
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   while(length >= 8)
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      {
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      SipRounds(load_le<uint64_t>(input, 0), m_V, m_C);
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      input += 8;
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      length -= 8;
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      }
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   for(size_t i = 0; i != length; ++i)
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      {
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      m_mbuf = (m_mbuf >> 8) | (static_cast<uint64_t>(input[i]) << 56);
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      m_mbuf_pos++;
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      }
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   }
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void SipHash::final_result(uint8_t mac[])
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   {
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   verify_key_set(m_V.empty() == false);
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   if(m_mbuf_pos == 0)
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      {
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      m_mbuf = (static_cast<uint64_t>(m_words) << 56);
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      }
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   else if(m_mbuf_pos < 8)
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      {
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      m_mbuf = (m_mbuf >> (64-m_mbuf_pos*8)) | (static_cast<uint64_t>(m_words) << 56);
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      }
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   SipRounds(m_mbuf, m_V, m_C);
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   m_V[2] ^= 0xFF;
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   SipRounds(0, m_V, m_D);
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   const uint64_t X = m_V[0] ^ m_V[1] ^ m_V[2] ^ m_V[3];
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   store_le(X, mac);
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   clear();
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   }
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void SipHash::key_schedule(const uint8_t key[], size_t)
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   {
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   const uint64_t K0 = load_le<uint64_t>(key, 0);
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   const uint64_t K1 = load_le<uint64_t>(key, 1);
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   m_V.resize(4);
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   m_V[0] = K0 ^ 0x736F6D6570736575;
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   m_V[1] = K1 ^ 0x646F72616E646F6D;
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   m_V[2] = K0 ^ 0x6C7967656E657261;
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   m_V[3] = K1 ^ 0x7465646279746573;
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   }
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void SipHash::clear()
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   {
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   zap(m_V);
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   m_mbuf = 0;
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   m_mbuf_pos = 0;
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   m_words = 0;
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   }
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std::string SipHash::name() const
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   {
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   return "SipHash(" + std::to_string(m_C) + "," + std::to_string(m_D) + ")";
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   }
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MessageAuthenticationCode* SipHash::clone() const
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   {
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   return new SipHash(m_C, m_D);
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   }
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}