noekeon.cpp

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/*
* Noekeon
* (C) 1999-2008 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#include <botan/internal/noekeon.h>
 
#include <botan/internal/loadstor.h>
#include <botan/internal/rotate.h>
 
#if defined(BOTAN_HAS_CPUID)
   #include <botan/internal/cpuid.h>
#endif
 
namespace Botan {
 
namespace {
 
/*
* Noekeon's Theta Operation
*/
inline void theta(uint32_t& A0, uint32_t& A1, uint32_t& A2, uint32_t& A3, const uint32_t EK[4]) {
   uint32_t T = A0 ^ A2;
   T ^= rotl<8>(T) ^ rotr<8>(T);
   A1 ^= T;
   A3 ^= T;
 
   A0 ^= EK[0];
   A1 ^= EK[1];
   A2 ^= EK[2];
   A3 ^= EK[3];
 
   T = A1 ^ A3;
   T ^= rotl<8>(T) ^ rotr<8>(T);
   A0 ^= T;
   A2 ^= T;
}
 
/*
* Theta With Null Key
*/
inline void theta(uint32_t& A0, uint32_t& A1, uint32_t& A2, uint32_t& A3) {
   uint32_t T = A0 ^ A2;
   T ^= rotl<8>(T) ^ rotr<8>(T);
   A1 ^= T;
   A3 ^= T;
 
   T = A1 ^ A3;
   T ^= rotl<8>(T) ^ rotr<8>(T);
   A0 ^= T;
   A2 ^= T;
}
 
/*
* Noekeon's Gamma S-Box Layer
*/
inline void gamma(uint32_t& A0, uint32_t& A1, uint32_t& A2, uint32_t& A3) {
   A1 ^= ~(A2 | A3);
   A0 ^= A2 & A1;
 
   uint32_t T = A3;
   A3 = A0;
   A0 = T;
 
   A2 ^= A0 ^ A1 ^ A3;
 
   A1 ^= ~(A2 | A3);
   A0 ^= A2 & A1;
}
 
}  // namespace
 
size_t Noekeon::parallelism() const {
#if defined(BOTAN_HAS_NOEKEON_SIMD)
   if(CPUID::has(CPUID::Feature::SIMD_4X32)) {
      return 4;
   }
#endif
 
   return 1;
}
 
std::string Noekeon::provider() const {
#if defined(BOTAN_HAS_NOEKEON_SIMD)
   if(auto feat = CPUID::check(CPUID::Feature::SIMD_4X32)) {
      return *feat;
   }
#endif
 
   return "base";
}
 
/*
* Noekeon Round Constants
*/
const uint8_t Noekeon::RC[] = {
   0x80, 0x1B, 0x36, 0x6C, 0xD8, 0xAB, 0x4D, 0x9A, 0x2F, 0x5E, 0xBC, 0x63, 0xC6, 0x97, 0x35, 0x6A, 0xD4};
 
/*
* Noekeon Encryption
*/
void Noekeon::encrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const {
   assert_key_material_set();
 
#if defined(BOTAN_HAS_NOEKEON_SIMD)
   if(CPUID::has(CPUID::Feature::SIMD_4X32)) {
      while(blocks >= 4) {
         simd_encrypt_4(in, out);
         in += 4 * BLOCK_SIZE;
         out += 4 * BLOCK_SIZE;
         blocks -= 4;
      }
   }
#endif
 
   for(size_t i = 0; i != blocks; ++i) {
      uint32_t A0 = load_be<uint32_t>(in, 0);
      uint32_t A1 = load_be<uint32_t>(in, 1);
      uint32_t A2 = load_be<uint32_t>(in, 2);
      uint32_t A3 = load_be<uint32_t>(in, 3);
 
      for(size_t j = 0; j != 16; ++j) {
         A0 ^= RC[j];
         theta(A0, A1, A2, A3, m_EK.data());
 
         A1 = rotl<1>(A1);
         A2 = rotl<5>(A2);
         A3 = rotl<2>(A3);
 
         gamma(A0, A1, A2, A3);
 
         A1 = rotr<1>(A1);
         A2 = rotr<5>(A2);
         A3 = rotr<2>(A3);
      }
 
      A0 ^= RC[16];
      theta(A0, A1, A2, A3, m_EK.data());
 
      store_be(out, A0, A1, A2, A3);
 
      in += BLOCK_SIZE;
      out += BLOCK_SIZE;
   }
}
 
/*
* Noekeon Encryption
*/
void Noekeon::decrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const {
   assert_key_material_set();
 
#if defined(BOTAN_HAS_NOEKEON_SIMD)
   if(CPUID::has(CPUID::Feature::SIMD_4X32)) {
      while(blocks >= 4) {
         simd_decrypt_4(in, out);
         in += 4 * BLOCK_SIZE;
         out += 4 * BLOCK_SIZE;
         blocks -= 4;
      }
   }
#endif
 
   for(size_t i = 0; i != blocks; ++i) {
      uint32_t A0 = load_be<uint32_t>(in, 0);
      uint32_t A1 = load_be<uint32_t>(in, 1);
      uint32_t A2 = load_be<uint32_t>(in, 2);
      uint32_t A3 = load_be<uint32_t>(in, 3);
 
      for(size_t j = 16; j != 0; --j) {
         theta(A0, A1, A2, A3, m_DK.data());
         A0 ^= RC[j];
 
         A1 = rotl<1>(A1);
         A2 = rotl<5>(A2);
         A3 = rotl<2>(A3);
 
         gamma(A0, A1, A2, A3);
 
         A1 = rotr<1>(A1);
         A2 = rotr<5>(A2);
         A3 = rotr<2>(A3);
      }
 
      theta(A0, A1, A2, A3, m_DK.data());
      A0 ^= RC[0];
 
      store_be(out, A0, A1, A2, A3);
 
      in += BLOCK_SIZE;
      out += BLOCK_SIZE;
   }
}
 
bool Noekeon::has_keying_material() const {
   return !m_EK.empty();
}
 
/*
* Noekeon Key Schedule
*/
void Noekeon::key_schedule(std::span<const uint8_t> key) {
   uint32_t A0 = load_be<uint32_t>(key.data(), 0);
   uint32_t A1 = load_be<uint32_t>(key.data(), 1);
   uint32_t A2 = load_be<uint32_t>(key.data(), 2);
   uint32_t A3 = load_be<uint32_t>(key.data(), 3);
 
   for(size_t i = 0; i != 16; ++i) {
      A0 ^= RC[i];
      theta(A0, A1, A2, A3);
 
      A1 = rotl<1>(A1);
      A2 = rotl<5>(A2);
      A3 = rotl<2>(A3);
 
      gamma(A0, A1, A2, A3);
 
      A1 = rotr<1>(A1);
      A2 = rotr<5>(A2);
      A3 = rotr<2>(A3);
   }
 
   A0 ^= RC[16];
 
   m_DK.resize(4);
   m_DK[0] = A0;
   m_DK[1] = A1;
   m_DK[2] = A2;
   m_DK[3] = A3;
 
   theta(A0, A1, A2, A3);
 
   m_EK.resize(4);
   m_EK[0] = A0;
   m_EK[1] = A1;
   m_EK[2] = A2;
   m_EK[3] = A3;
}
 
/*
* Clear memory of sensitive data
*/
void Noekeon::clear() {
   zap(m_EK);
   zap(m_DK);
}
 
}  // namespace Botan