diff options
Diffstat (limited to 'src/lib/math/bigint/bigint.h')
| -rw-r--r-- | src/lib/math/bigint/bigint.h | 204 |
1 files changed, 165 insertions, 39 deletions
diff --git a/src/lib/math/bigint/bigint.h b/src/lib/math/bigint/bigint.h index aa2701fa4..530fd5ecf 100644 --- a/src/lib/math/bigint/bigint.h +++ b/src/lib/math/bigint/bigint.h @@ -59,7 +59,7 @@ class BOTAN_PUBLIC_API(2,0) BigInt final * Copy Constructor * @param other the BigInt to copy */ - BigInt(const BigInt& other); + BigInt(const BigInt& other) = default; /** * Create BigInt from a string. If the string starts with 0x the @@ -156,13 +156,14 @@ class BOTAN_PUBLIC_API(2,0) BigInt final */ void swap(BigInt& other) { - m_reg.swap(other.m_reg); + m_data.swap(other.m_data); std::swap(m_signedness, other.m_signedness); } void swap_reg(secure_vector<word>& reg) { - m_reg.swap(reg); + m_data.swap(reg); + // sign left unchanged } /** @@ -318,7 +319,7 @@ class BOTAN_PUBLIC_API(2,0) BigInt final * Zeroize the BigInt. The size of the underlying register is not * modified. */ - void clear() { zeroise(m_reg); } + void clear() { m_data.set_to_zero(); } /** * Compare this to another BigInt @@ -382,20 +383,7 @@ class BOTAN_PUBLIC_API(2,0) BigInt final */ void mask_bits(size_t n) { - if(n == 0) { clear(); return; } - - const size_t top_word = n / BOTAN_MP_WORD_BITS; - const word mask = (static_cast<word>(1) << (n % BOTAN_MP_WORD_BITS)) - 1; - - if(top_word < size()) - { - const size_t len = size() - (top_word + 1); - if (len > 0) - { - clear_mem(&m_reg[top_word+1], len); - } - m_reg[top_word] &= mask; - } + m_data.mask_bits(n); } /** @@ -451,19 +439,18 @@ class BOTAN_PUBLIC_API(2,0) BigInt final * @return value at position n */ word word_at(size_t n) const - { return ((n < size()) ? m_reg[n] : 0); } + { + return m_data.get_word_at(n); + } void set_word_at(size_t i, word w) { - if(i >= m_reg.size()) - grow_to(i + 1); - m_reg[i] = w; + m_data.set_word_at(i, w); } void set_words(const word w[], size_t len) { - m_reg.resize(len); - copy_mem(mutable_data(), w, len); + m_data.set_words(w, len); } /** @@ -523,7 +510,7 @@ class BOTAN_PUBLIC_API(2,0) BigInt final * Give size of internal register * @result size of internal register in words */ - size_t size() const { return m_reg.size(); } + size_t size() const { return m_data.size(); } /** * Return how many words we need to hold this value @@ -531,12 +518,7 @@ class BOTAN_PUBLIC_API(2,0) BigInt final */ size_t sig_words() const { - const word* x = m_reg.data(); - size_t sig = m_reg.size(); - - while(sig && (x[sig-1] == 0)) - sig--; - return sig; + return m_data.sig_words(); } /** @@ -555,22 +537,29 @@ class BOTAN_PUBLIC_API(2,0) BigInt final * Return a mutable pointer to the register * @result a pointer to the start of the internal register */ - word* mutable_data() { return m_reg.data(); } + word* mutable_data() { return m_data.mutable_data(); } /** * Return a const pointer to the register * @result a pointer to the start of the internal register */ - const word* data() const { return m_reg.data(); } + const word* data() const { return m_data.const_data(); } - secure_vector<word>& get_word_vector() { return m_reg; } - const secure_vector<word>& get_word_vector() const { return m_reg; } + /** + * Don't use this function in application code + */ + secure_vector<word>& get_word_vector() { return m_data.mutable_vector(); } + + /** + * Don't use this function in application code + */ + const secure_vector<word>& get_word_vector() const { return m_data.const_vector(); } /** * Increase internal register buffer to at least n words * @param n new size of register */ - void grow_to(size_t n); + void grow_to(size_t n) { m_data.grow_to(n); } /** * Resize the vector to the minimum word size to hold the integer, or @@ -578,8 +567,7 @@ class BOTAN_PUBLIC_API(2,0) BigInt final */ void shrink_to_fit(size_t min_size = 0) { - const size_t words = std::max(min_size, sig_words()); - m_reg.resize(words); + m_data.shrink_to_fit(min_size); } /** @@ -822,7 +810,145 @@ class BOTAN_PUBLIC_API(2,0) BigInt final size_t idx); private: - secure_vector<word> m_reg; + + class Data + { + public: + word* mutable_data() + { + invalidate_sig_words(); + return m_reg.data(); + } + + const word* const_data() const + { + return m_reg.data(); + } + + secure_vector<word>& mutable_vector() + { + invalidate_sig_words(); + return m_reg; + } + + const secure_vector<word>& const_vector() const + { + return m_reg; + } + + word get_word_at(size_t n) const + { + if(n < m_reg.size()) + return m_reg[n]; + return 0; + } + + void set_word_at(size_t i, word w) + { + invalidate_sig_words(); + if(i >= m_reg.size()) + grow_to(i + 1); + m_reg[i] = w; + } + + void set_words(const word w[], size_t len) + { + invalidate_sig_words(); + m_reg.assign(w, w + len); + } + + void set_to_zero() + { + m_reg.resize(m_reg.capacity()); + clear_mem(m_reg.data(), m_reg.size()); + m_sig_words = 0; + } + + void set_size(size_t s) + { + invalidate_sig_words(); + clear_mem(m_reg.data(), m_reg.size()); + m_reg.resize(s + (8 - (s % 8))); + } + + void mask_bits(size_t n) + { + if(n == 0) { return set_to_zero(); } + + const size_t top_word = n / BOTAN_MP_WORD_BITS; + + // if(top_word < sig_words()) ? + if(top_word < size()) + { + const word mask = (static_cast<word>(1) << (n % BOTAN_MP_WORD_BITS)) - 1; + const size_t len = size() - (top_word + 1); + if (len > 0) + { + clear_mem(&m_reg[top_word+1], len); + } + m_reg[top_word] &= mask; + invalidate_sig_words(); + } + } + + void grow_to(size_t n) + { + if(n > size()) + { + if(n <= m_reg.capacity()) + m_reg.resize(m_reg.capacity()); + else + m_reg.resize(n + (8 - (n % 8))); + } + } + + size_t size() const { return m_reg.size(); } + + void shrink_to_fit(size_t min_size = 0) + { + const size_t words = std::max(min_size, sig_words()); + m_reg.resize(words); + } + + void swap(Data& other) + { + m_reg.swap(other.m_reg); + std::swap(m_sig_words, other.m_sig_words); + } + + void swap(secure_vector<word>& reg) + { + m_reg.swap(reg); + invalidate_sig_words(); + } + + void invalidate_sig_words() const + { + m_sig_words = sig_words_npos; + } + + size_t sig_words() const + { + if(m_sig_words == sig_words_npos) + { + m_sig_words = calc_sig_words(); + } + else + { + BOTAN_DEBUG_ASSERT(m_sig_words == calc_sig_words()); + } + return m_sig_words; + } + private: + static const size_t sig_words_npos = static_cast<size_t>(-1); + + size_t calc_sig_words() const; + + secure_vector<word> m_reg; + mutable size_t m_sig_words = sig_words_npos; + }; + + Data m_data; Sign m_signedness = Positive; }; |