1 files changed, 115 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/utils/poly_dbl/poly_dbl.cpp b/comm/third_party/botan/src/lib/utils/poly_dbl/poly_dbl.cpp
new file mode 100644
index 0000000000..8c728a1480
--- /dev/null
+++ b/comm/third_party/botan/src/lib/utils/poly_dbl/poly_dbl.cpp
@@ -0,0 +1,115 @@
+/*
+* (C) 2017,2018 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/internal/poly_dbl.h>
+#include <botan/loadstor.h>
+#include <botan/exceptn.h>
+
+namespace Botan {
+
+namespace {
+
+/*
+* The minimum weight irreducible binary polynomial of size n
+*
+* See http://www.hpl.hp.com/techreports/98/HPL-98-135.pdf
+*/
+enum class MinWeightPolynomial : uint64_t {
+   P64   = 0x1B,
+   P128  = 0x87,
+   P192  = 0x87,
+   P256  = 0x425,
+   P512  = 0x125,
+   P1024 = 0x80043,
+};
+
+template<size_t LIMBS, MinWeightPolynomial P>
+void poly_double(uint8_t out[], const uint8_t in[])
+   {
+   uint64_t W[LIMBS];
+   load_be(W, in, LIMBS);
+
+   const uint64_t POLY = static_cast<uint64_t>(P);
+
+   const uint64_t carry = POLY * (W[0] >> 63);
+
+   BOTAN_IF_CONSTEXPR(LIMBS > 0)
+      {
+      for(size_t i = 0; i != LIMBS - 1; ++i)
+         W[i] = (W[i] << 1) ^ (W[i+1] >> 63);
+      }
+
+   W[LIMBS-1] = (W[LIMBS-1] << 1) ^ carry;
+
+   copy_out_be(out, LIMBS*8, W);
+   }
+
+template<size_t LIMBS, MinWeightPolynomial P>
+void poly_double_le(uint8_t out[], const uint8_t in[])
+   {
+   uint64_t W[LIMBS];
+   load_le(W, in, LIMBS);
+
+   const uint64_t POLY = static_cast<uint64_t>(P);
+
+   const uint64_t carry = POLY * (W[LIMBS-1] >> 63);
+
+   BOTAN_IF_CONSTEXPR(LIMBS > 0)
+      {
+      for(size_t i = 0; i != LIMBS - 1; ++i)
+         W[LIMBS-1-i] = (W[LIMBS-1-i] << 1) ^ (W[LIMBS-2-i] >> 63);
+      }
+
+   W[0] = (W[0] << 1) ^ carry;
+
+   copy_out_le(out, LIMBS*8, W);
+   }
+
+}
+
+void poly_double_n(uint8_t out[], const uint8_t in[], size_t n)
+   {
+   switch(n)
+      {
+      case 8:
+         return poly_double<1, MinWeightPolynomial::P64>(out, in);
+      case 16:
+         return poly_double<2, MinWeightPolynomial::P128>(out, in);
+      case 24:
+         return poly_double<3, MinWeightPolynomial::P192>(out, in);
+      case 32:
+         return poly_double<4, MinWeightPolynomial::P256>(out, in);
+      case 64:
+         return poly_double<8, MinWeightPolynomial::P512>(out, in);
+      case 128:
+         return poly_double<16, MinWeightPolynomial::P1024>(out, in);
+      default:
+         throw Invalid_Argument("Unsupported size for poly_double_n");
+      }
+   }
+
+void poly_double_n_le(uint8_t out[], const uint8_t in[], size_t n)
+   {
+   switch(n)
+      {
+      case 8:
+         return poly_double_le<1, MinWeightPolynomial::P64>(out, in);
+      case 16:
+         return poly_double_le<2, MinWeightPolynomial::P128>(out, in);
+      case 24:
+         return poly_double_le<3, MinWeightPolynomial::P192>(out, in);
+      case 32:
+         return poly_double_le<4, MinWeightPolynomial::P256>(out, in);
+      case 64:
+         return poly_double_le<8, MinWeightPolynomial::P512>(out, in);
+      case 128:
+         return poly_double_le<16, MinWeightPolynomial::P1024>(out, in);
+      default:
+         throw Invalid_Argument("Unsupported size for poly_double_n_le");
+      }
+   }
+
+}