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<?php |
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declare(strict_types=1); |
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namespace BitWasp\Bitcoin\Math; |
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use Mdanter\Ecc\Math\GmpMath; |
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use Mdanter\Ecc\Util\NumberSize; |
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class Math extends GmpMath |
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{ |
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/** |
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* @param \GMP $integer |
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* @return bool |
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*/ |
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94 |
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public function isEven(\GMP $integer): bool |
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{ |
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return $this->cmp($this->mod($integer, gmp_init(2)), gmp_init(0)) === 0; |
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} |
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/** |
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* @param \GMP $int |
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* @param \GMP $otherInt |
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* @return \GMP |
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*/ |
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1695 |
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public function bitwiseOr(\GMP $int, \GMP $otherInt): \GMP |
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{ |
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1695 |
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return gmp_or($int, $otherInt); |
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} |
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/** |
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* Similar to gmp_div_qr, return a tuple containing the |
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* result and the remainder |
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* |
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* @param \GMP $dividend |
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* @param \GMP $divisor |
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* @return array |
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*/ |
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public function divQr(\GMP $dividend, \GMP $divisor): array |
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{ |
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// $div = n / q |
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$div = $this->div($dividend, $divisor); |
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// $remainder = n - (n / q) * q |
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$remainder = $this->sub($dividend, $this->mul($div, $divisor)); |
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return [$div, $remainder]; |
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} |
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/** |
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* @param int $compact |
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* @param bool|false $isNegative |
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* @param bool|false $isOverflow |
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* @return \GMP |
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*/ |
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210 |
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public function decodeCompact($compact, &$isNegative, &$isOverflow): \GMP |
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{ |
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210 |
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if ($compact < 0 || $compact > pow(2, 32) - 1) { |
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throw new \RuntimeException('Compact integer must be 32bit'); |
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} |
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210 |
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$compact = gmp_init($compact, 10); |
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210 |
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$size = $this->rightShift($compact, 24); |
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210 |
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$word = $this->bitwiseAnd($compact, gmp_init(0x007fffff, 10)); |
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210 |
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if ($this->cmp($size, gmp_init(3)) <= 0) { |
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13 |
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$positions = (int) $this->toString($this->mul(gmp_init(8, 10), $this->sub(gmp_init(3, 10), $size))); |
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13 |
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$word = $this->rightShift($word, $positions); |
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} else { |
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197 |
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$positions = (int) $this->toString($this->mul(gmp_init(8, 10), $this->sub($size, gmp_init(3, 10)))); |
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$word = $this->leftShift($word, $positions); |
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} |
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// isNegative: $word !== 0 && $uint32 & 0x00800000 !== 0 |
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// isOverflow: $word !== 0 && (($size > 34) || ($word > 0xff && $size > 33) || ($word > 0xffff && $size > 32)) |
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210 |
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$zero = gmp_init(0); |
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210 |
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$isNegative = ($this->cmp($word, $zero) !== 0) && ($this->cmp($this->bitwiseAnd($compact, gmp_init(0x00800000)), $zero) === 1); |
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210 |
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$isOverflow = $this->cmp($word, $zero) !== 0 && ( |
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($this->cmp($size, gmp_init(34, 10)) > 0) |
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|| ($this->cmp($word, gmp_init(0xff, 10)) > 0 && $this->cmp($size, gmp_init(33, 10)) > 0) |
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210 |
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|| ($this->cmp($word, gmp_init(0xffff, 10)) > 0 && $this->cmp($size, gmp_init(32, 10)) > 0) |
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); |
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210 |
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return $word; |
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} |
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/** |
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* @param \GMP $integer |
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* @return \GMP |
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*/ |
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18 |
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public function getLow64(\GMP $integer): \GMP |
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{ |
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$bits = gmp_strval($integer, 2); |
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$bits = substr($bits, 0, 64); |
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$bits = str_pad($bits, 64, '0', STR_PAD_LEFT); |
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return gmp_init($bits, 2); |
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} |
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/** |
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* @param \GMP $int |
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* @param int $byteSize |
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* @return string |
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*/ |
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public function fixedSizeInt(\GMP $int, int $byteSize): string |
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{ |
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$two = gmp_init(2); |
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$maskShift = gmp_pow($two, 8); |
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$mask = gmp_mul(gmp_init(255), gmp_pow($two, 256)); |
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$x = ''; |
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for ($i = $byteSize - 1; $i >= 0; $i--) { |
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$mask = gmp_div($mask, $maskShift); |
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$x .= pack('C', gmp_strval(gmp_div(gmp_and($int, $mask), gmp_pow($two, $i * 8)), 10)); |
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} |
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return $x; |
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} |
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/** |
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* @param \GMP $integer |
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* @param bool $fNegative |
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* @return \GMP |
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*/ |
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public function encodeCompact(\GMP $integer, bool $fNegative): \GMP |
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{ |
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if (!is_bool($fNegative)) { |
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throw new \InvalidArgumentException('CompactInteger::read() - flag must be boolean!'); |
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} |
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$size = (int) NumberSize::bnNumBytes($this, $integer); |
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if ($size <= 3) { |
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$compact = $this->leftShift($this->getLow64($integer), (8 * (3 - $size))); |
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} else { |
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$compact = $this->rightShift($integer, 8 * ($size - 3)); |
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$compact = $this->getLow64($compact); |
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} |
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if ($this->cmp($this->bitwiseAnd($compact, gmp_init(0x00800000, 10)), gmp_init(0, 10)) > 0) { |
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1 |
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$compact = $this->rightShift($compact, 8); |
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1 |
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$size = $size + 1; |
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} |
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$compact = $this->bitwiseOr($compact, $this->leftShift(gmp_init($size, 10), 24)); |
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if ($fNegative && $this->cmp($this->bitwiseAnd($compact, gmp_init(0x007fffff, 10)), gmp_init(0, 10)) > 0) { /// ? |
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2 |
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$compact = $this->bitwiseOr($compact, gmp_init(0x00800000, 10)); |
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} |
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return $compact; |
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} |
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} |
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Bit-Wasp /
bitcoin-php
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