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author | Eike Ziller <eike.ziller@qt.io> | 2018-08-15 13:53:28 +0200 |
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committer | Eike Ziller <eike.ziller@qt.io> | 2018-08-15 13:53:28 +0200 |
commit | db9837fa6c9401e898ac8e7492081a6e21c71790 (patch) | |
tree | d542a089711257402ac4fe70813fa0e7de825f2e /src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp | |
parent | 7bc14bf3498ea6b1c19abacf85a5103772da26bc (diff) | |
parent | 58747b2de107e8f6ac00daeb431ecbf3e603fd34 (diff) |
Merge remote-tracking branch 'origin/4.7'
Conflicts:
src/plugins/clangtools/clangtoolruncontrol.cpp
src/plugins/cpptools/compileroptionsbuilder.cpp
Change-Id: Ib1e8abf066898b50c90fc1ccba4697fe983e8a8f
Diffstat (limited to 'src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp')
-rw-r--r-- | src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp b/src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp new file mode 100644 index 0000000000..85a0364b5a --- /dev/null +++ b/src/libs/3rdparty/botan/src/lib/math/numbertheory/powm_fw.cpp @@ -0,0 +1,65 @@ +/* +* Fixed Window Exponentiation +* (C) 1999-2007 Jack Lloyd +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/internal/def_powm.h> +#include <vector> + +namespace Botan { + +/* +* Set the exponent +*/ +void Fixed_Window_Exponentiator::set_exponent(const BigInt& e) + { + m_exp = e; + } + +/* +* Set the base +*/ +void Fixed_Window_Exponentiator::set_base(const BigInt& base) + { + m_window_bits = Power_Mod::window_bits(m_exp.bits(), base.bits(), m_hints); + + m_g.resize(1U << m_window_bits); + m_g[0] = 1; + m_g[1] = base; + + for(size_t i = 2; i != m_g.size(); ++i) + m_g[i] = m_reducer.multiply(m_g[i-1], m_g[1]); + } + +/* +* Compute the result +*/ +BigInt Fixed_Window_Exponentiator::execute() const + { + const size_t exp_nibbles = (m_exp.bits() + m_window_bits - 1) / m_window_bits; + + BigInt x = 1; + + for(size_t i = exp_nibbles; i > 0; --i) + { + for(size_t j = 0; j != m_window_bits; ++j) + x = m_reducer.square(x); + + const uint32_t nibble = m_exp.get_substring(m_window_bits*(i-1), m_window_bits); + + x = m_reducer.multiply(x, m_g[nibble]); + } + return x; + } + +/* +* Fixed_Window_Exponentiator Constructor +*/ +Fixed_Window_Exponentiator::Fixed_Window_Exponentiator(const BigInt& n, + Power_Mod::Usage_Hints hints) + : m_reducer{Modular_Reducer(n)}, m_exp{}, m_window_bits{}, m_g{}, m_hints{hints} + {} + +} |