diff options
Diffstat (limited to 'src/math/bigint/bigint.cpp')
| -rw-r--r-- | src/math/bigint/bigint.cpp | 178 |
1 files changed, 90 insertions, 88 deletions
diff --git a/src/math/bigint/bigint.cpp b/src/math/bigint/bigint.cpp index e3c7931e6..926bedc02 100644 --- a/src/math/bigint/bigint.cpp +++ b/src/math/bigint/bigint.cpp @@ -1,7 +1,9 @@ -/************************************************* -* BigInt Base Source File * -* (C) 1999-2008 Jack Lloyd * -*************************************************/ +/* +* BigInt Base +* (C) 1999-2008 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ #include <botan/bigint.h> #include <botan/mp_core.h> @@ -11,9 +13,9 @@ namespace Botan { -/************************************************* -* Construct a BigInt from a regular number * -*************************************************/ +/* +* Construct a BigInt from a regular number +*/ BigInt::BigInt(u64bit n) { set_sign(Positive); @@ -28,18 +30,18 @@ BigInt::BigInt(u64bit n) reg[j] = ((n >> (j*MP_WORD_BITS)) & MP_WORD_MASK); } -/************************************************* -* Construct a BigInt of the specified size * -*************************************************/ +/* +* Construct a BigInt of the specified size +*/ BigInt::BigInt(Sign s, u32bit size) { reg.create(round_up(size, 8)); signedness = s; } -/************************************************* -* Construct a BigInt from a "raw" BigInt * -*************************************************/ +/* +* Construct a BigInt from a "raw" BigInt +*/ BigInt::BigInt(const BigInt& b) { const u32bit b_words = b.sig_words(); @@ -57,9 +59,9 @@ BigInt::BigInt(const BigInt& b) } } -/************************************************* -* Construct a BigInt from a string * -*************************************************/ +/* +* Construct a BigInt from a string +*/ BigInt::BigInt(const std::string& str) { Base base = Decimal; @@ -80,53 +82,53 @@ BigInt::BigInt(const std::string& str) else set_sign(Positive); } -/************************************************* -* Construct a BigInt from an encoded BigInt * -*************************************************/ +/* +* Construct a BigInt from an encoded BigInt +*/ BigInt::BigInt(const byte input[], u32bit length, Base base) { set_sign(Positive); *this = decode(input, length, base); } -/************************************************* -* Construct a BigInt from an encoded BigInt * -*************************************************/ +/* +* Construct a BigInt from an encoded BigInt +*/ BigInt::BigInt(RandomNumberGenerator& rng, u32bit bits) { set_sign(Positive); randomize(rng, bits); } -/************************************************* -* Swap this BigInt with another * -*************************************************/ +/* +* Swap this BigInt with another +*/ void BigInt::swap(BigInt& other) { reg.swap(other.reg); std::swap(signedness, other.signedness); } -/************************************************* -* Grow the internal storage * -*************************************************/ +/* +* Grow the internal storage +*/ void BigInt::grow_reg(u32bit n) { reg.grow_to(round_up(size() + n, 8)); } -/************************************************* -* Grow the internal storage * -*************************************************/ +/* +* Grow the internal storage +*/ void BigInt::grow_to(u32bit n) { if(n > size()) reg.grow_to(round_up(n, 8)); } -/************************************************* -* Comparison Function * -*************************************************/ +/* +* Comparison Function +*/ s32bit BigInt::cmp(const BigInt& n, bool check_signs) const { if(check_signs) @@ -139,9 +141,9 @@ s32bit BigInt::cmp(const BigInt& n, bool check_signs) const return bigint_cmp(data(), sig_words(), n.data(), n.sig_words()); } -/************************************************* -* Convert this number to a u32bit, if possible * -*************************************************/ +/* +* Convert this number to a u32bit, if possible +*/ u32bit BigInt::to_u32bit() const { if(is_negative()) @@ -155,9 +157,9 @@ u32bit BigInt::to_u32bit() const return out; } -/************************************************* -* Return byte n of this number * -*************************************************/ +/* +* Return byte n of this number +*/ byte BigInt::byte_at(u32bit n) const { const u32bit WORD_BYTES = sizeof(word); @@ -168,17 +170,17 @@ byte BigInt::byte_at(u32bit n) const return get_byte(WORD_BYTES - byte_num - 1, reg[word_num]); } -/************************************************* -* Return bit n of this number * -*************************************************/ +/* +* Return bit n of this number +*/ bool BigInt::get_bit(u32bit n) const { return ((word_at(n / MP_WORD_BITS) >> (n % MP_WORD_BITS)) & 1); } -/************************************************* -* Return bits {offset...offset+length} * -*************************************************/ +/* +* Return bits {offset...offset+length} +*/ u32bit BigInt::get_substring(u32bit offset, u32bit length) const { if(length > 32) @@ -194,9 +196,9 @@ u32bit BigInt::get_substring(u32bit offset, u32bit length) const return static_cast<u32bit>((piece >> shift) & mask); } -/************************************************* -* Set bit number n * -*************************************************/ +/* +* Set bit number n +*/ void BigInt::set_bit(u32bit n) { const u32bit which = n / MP_WORD_BITS; @@ -205,9 +207,9 @@ void BigInt::set_bit(u32bit n) reg[which] |= mask; } -/************************************************* -* Clear bit number n * -*************************************************/ +/* +* Clear bit number n +*/ void BigInt::clear_bit(u32bit n) { const u32bit which = n / MP_WORD_BITS; @@ -216,9 +218,9 @@ void BigInt::clear_bit(u32bit n) reg[which] &= ~mask; } -/************************************************* -* Clear all but the lowest n bits * -*************************************************/ +/* +* Clear all but the lowest n bits +*/ void BigInt::mask_bits(u32bit n) { if(n == 0) { clear(); return; } @@ -234,17 +236,17 @@ void BigInt::mask_bits(u32bit n) reg[top_word] &= mask; } -/************************************************* -* Count how many bytes are being used * -*************************************************/ +/* +* Count how many bytes are being used +*/ u32bit BigInt::bytes() const { return (bits() + 7) / 8; } -/************************************************* -* Count how many bits are being used * -*************************************************/ +/* +* Count how many bits are being used +*/ u32bit BigInt::bits() const { if(sig_words() == 0) @@ -259,9 +261,9 @@ u32bit BigInt::bits() const return (full_words * MP_WORD_BITS + top_bits); } -/************************************************* -* Calcluate the size in a certain base * -*************************************************/ +/* +* Calcluate the size in a certain base +*/ u32bit BigInt::encoded_size(Base base) const { static const double LOG_2_BASE_10 = 0.30102999566; @@ -278,9 +280,9 @@ u32bit BigInt::encoded_size(Base base) const throw Invalid_Argument("Unknown base for BigInt encoding"); } -/************************************************* -* Set the sign * -*************************************************/ +/* +* Set the sign +*/ void BigInt::set_sign(Sign s) { if(is_zero()) @@ -289,17 +291,17 @@ void BigInt::set_sign(Sign s) signedness = s; } -/************************************************* -* Reverse the value of the sign flag * -*************************************************/ +/* +* Reverse the value of the sign flag +*/ void BigInt::flip_sign() { set_sign(reverse_sign()); } -/************************************************* -* Return the opposite value of the current sign * -*************************************************/ +/* +* Return the opposite value of the current sign +*/ BigInt::Sign BigInt::reverse_sign() const { if(sign() == Positive) @@ -307,9 +309,9 @@ BigInt::Sign BigInt::reverse_sign() const return Positive; } -/************************************************* -* Return the negation of this number * -*************************************************/ +/* +* Return the negation of this number +*/ BigInt BigInt::operator-() const { BigInt x = (*this); @@ -317,9 +319,9 @@ BigInt BigInt::operator-() const return x; } -/************************************************* -* Return the absolute value of this number * -*************************************************/ +/* +* Return the absolute value of this number +*/ BigInt BigInt::abs() const { BigInt x = (*this); @@ -327,9 +329,9 @@ BigInt BigInt::abs() const return x; } -/************************************************* -* Encode this number into bytes * -*************************************************/ +/* +* Encode this number into bytes +*/ void BigInt::binary_encode(byte output[]) const { const u32bit sig_bytes = bytes(); @@ -337,9 +339,9 @@ void BigInt::binary_encode(byte output[]) const output[sig_bytes-j-1] = byte_at(j); } -/************************************************* -* Set this number to the value in buf * -*************************************************/ +/* +* Set this number to the value in buf +*/ void BigInt::binary_decode(const byte buf[], u32bit length) { const u32bit WORD_BYTES = sizeof(word); @@ -356,9 +358,9 @@ void BigInt::binary_decode(const byte buf[], u32bit length) reg[length / WORD_BYTES] = (reg[length / WORD_BYTES] << 8) | buf[j]; } -/************************************************* -* Set this number to the value in buf * -*************************************************/ +/* +* Set this number to the value in buf +*/ void BigInt::binary_decode(const MemoryRegion<byte>& buf) { binary_decode(buf, buf.size()); |