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<?php |
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|
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// Do not allow the file to be called directly. |
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if ( ! defined( 'ABSPATH' ) ) { |
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exit; |
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} |
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|
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/** |
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* Encode in Base32 based on RFC 4648. |
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* Requires 20% more space than base64 |
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* Great for case-insensitive filesystems like Windows and URL's (except for = char which can be excluded using the pad option for urls) |
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* |
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* @package default |
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* @author Bryan Ruiz |
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**/ |
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class Base32Static { |
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|
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private static $map = [ |
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'A', |
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'B', |
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'C', |
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'D', |
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'E', |
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'F', |
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'G', |
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'H', // 7 |
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'I', |
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'J', |
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'K', |
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'L', |
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'M', |
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'N', |
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'O', |
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'P', // 15 |
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'Q', |
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'R', |
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'S', |
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'T', |
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'U', |
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'V', |
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'W', |
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'X', // 23 |
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'Y', |
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'Z', |
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'2', |
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'3', |
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'4', |
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'5', |
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'6', |
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'7', // 31 |
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'=', // padding character |
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]; |
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|
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private static $flipped_map = [ |
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'A' => '0', |
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'B' => '1', |
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'C' => '2', |
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'D' => '3', |
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'E' => '4', |
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'F' => '5', |
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'G' => '6', |
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'H' => '7', |
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'I' => '8', |
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'J' => '9', |
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'K' => '10', |
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'L' => '11', |
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'M' => '12', |
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'N' => '13', |
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'O' => '14', |
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'P' => '15', |
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'Q' => '16', |
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'R' => '17', |
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'S' => '18', |
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'T' => '19', |
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'U' => '20', |
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'V' => '21', |
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'W' => '22', |
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'X' => '23', |
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'Y' => '24', |
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'Z' => '25', |
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'2' => '26', |
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'3' => '27', |
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'4' => '28', |
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'5' => '29', |
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'6' => '30', |
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'7' => '31', |
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]; |
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|
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/** |
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* Use padding false when encoding for urls |
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* |
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* @return base32 encoded string |
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* @author Bryan Ruiz |
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**/ |
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public static function encode( $input, $padding = true ) { |
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if ( empty( $input ) ) { |
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return ''; |
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} |
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|
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$input = str_split( $input ); |
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$binary_string = ''; |
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|
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for ( $i = 0; $i < count( $input ); $i++ ) { |
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$binary_string .= str_pad( base_convert( ord( $input[ $i ] ), 10, 2 ), 8, '0', STR_PAD_LEFT ); |
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} |
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|
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$five_bit_binary_array = str_split( $binary_string, 5 ); |
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$base32 = ''; |
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$i = 0; |
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|
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while ( $i < count( $five_bit_binary_array ) ) { |
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$base32 .= self::$map[ base_convert( str_pad( $five_bit_binary_array[ $i ], 5, '0' ), 2, 10 ) ]; |
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$i++; |
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} |
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|
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if ( $padding && ( $x = strlen( $binary_string ) % 40 ) != 0 ) { |
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if ( $x == 8 ) { |
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$base32 .= str_repeat( self::$map[32], 6 ); |
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} elseif ( $x == 16 ) { |
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$base32 .= str_repeat( self::$map[32], 4 ); |
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} elseif ( $x == 24 ) { |
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$base32 .= str_repeat( self::$map[32], 3 ); |
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} elseif ( $x == 32 ) { |
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$base32 .= self::$map[32]; |
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} |
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} |
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|
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return $base32; |
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} |
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|
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public static function decode( $input ) { |
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if ( empty( $input ) ) { |
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return; |
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} |
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|
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$padding_char_count = substr_count( $input, self::$map[32] ); |
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$allowed_values = [ 6, 4, 3, 1, 0 ]; |
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|
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if ( ! in_array( $padding_char_count, $allowed_values ) ) { |
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return false; |
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} |
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|
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for ( $i = 0; $i < 4; $i++ ) { |
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if ( $padding_char_count == $allowed_values[ $i ] && substr( $input, -( $allowed_values[ $i ] ) ) != str_repeat( self::$map[32], $allowed_values[ $i ] ) ) { |
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return false; |
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} |
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} |
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|
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$input = str_replace( '=', '', $input ); |
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$input = str_split( $input ); |
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$binary_string = ''; |
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|
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for ( $i = 0; $i < count( $input ); $i = $i + 8 ) { |
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$x = ''; |
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|
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if ( ! in_array( $input[ $i ], self::$map ) ) { |
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return false; |
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} |
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|
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for ( $j = 0; $j < 8; $j++ ) { |
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$x .= str_pad( base_convert( @self::$flipped_map[ @$input[ $i + $j ] ], 10, 2 ), 5, '0', STR_PAD_LEFT ); |
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} |
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|
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$eight_bits = str_split( $x, 8 ); |
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|
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for ( $z = 0; $z < count( $eight_bits ); $z++ ) { |
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$binary_string .= ( ( $y = chr( base_convert( $eight_bits[ $z ], 2, 10 ) ) ) || ord( $y ) == 48 ) ? $y : ''; |
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} |
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} |
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|
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return $binary_string; |
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} |
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} |
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|
