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Diffstat (limited to 'ecdsa_fpga_multiword.cpp')
| -rw-r--r-- | ecdsa_fpga_multiword.cpp | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/ecdsa_fpga_multiword.cpp b/ecdsa_fpga_multiword.cpp new file mode 100644 index 0000000..ab65e7a --- /dev/null +++ b/ecdsa_fpga_multiword.cpp @@ -0,0 +1,107 @@ +//------------------------------------------------------------------------------ +// +// fpga_ecdsa_multiword.cpp +// ----------------------------------------- +// Models of multi-precision FPGA primitives +// +// Authors: Pavel Shatov +// +// Copyright (c) 2015-2016, 2018 NORDUnet A/S +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// +// - Redistributions of source code must retain the above copyright notice, +// this list of conditions and the following disclaimer. +// +// - Redistributions in binary form must reproduce the above copyright notice, +// this list of conditions and the following disclaimer in the documentation +// and/or other materials provided with the distribution. +// +// - Neither the name of the NORDUnet nor the names of its contributors may be +// used to endorse or promote products derived from this software without +// specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE +// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +// POSSIBILITY OF SUCH DAMAGE. +// +//------------------------------------------------------------------------------ + + +//------------------------------------------------------------------------------ +// Headers +//------------------------------------------------------------------------------ +#include "ecdsa_fpga_model.h" + + +//------------------------------------------------------------------------------ +// Globals +//------------------------------------------------------------------------------ +FPGA_BUFFER ECDSA_ZERO; +FPGA_BUFFER ECDSA_ONE; + + +//------------------------------------------------------------------------------ +void fpga_multiword_init() +//------------------------------------------------------------------------------ +{ + int w; // word counter + + /* fill buffers for large multi-word integers */ + for ( w = FPGA_OPERAND_NUM_WORDS - 1; + w >= 0; + w -= 1) + { + ECDSA_ZERO.words[w] = 0; // all words are zero + ECDSA_ONE.words[w] = w ? 0 : 1; // only the lowest word is 1 + } +} + + +//------------------------------------------------------------------------------ +void fpga_multiword_copy(const FPGA_BUFFER *src, FPGA_BUFFER *dst) +//------------------------------------------------------------------------------ +// +// Copies large multi-word integer from src into dst. +// +//------------------------------------------------------------------------------ +{ + int w; // word counter + + // copy all the words from src into dst + for (w=0; w<FPGA_OPERAND_NUM_WORDS; w++) + dst->words[w] = src->words[w]; +} + + +//------------------------------------------------------------------------------ +bool fpga_multiword_is_zero(const FPGA_BUFFER *x) +//------------------------------------------------------------------------------ +// +// Returns true when large multi-word integer x is zero. +// +//------------------------------------------------------------------------------ +{ + int w; // word counter + + // try to find non-zero words + for (w=0; w<FPGA_OPERAND_NUM_WORDS; w++) + if (x->words[w]) return false; + + // no non-zero words found + return true; +} + + +//------------------------------------------------------------------------------ +// End-of-File +//------------------------------------------------------------------------------ |