gentium
2 years ago
tmp
2 years ago
license.txt
2 years ago
readme.txt
2 years ago
really-simple-captcha.php
2 years ago
really-simple-captcha.php
353 lines
| 1 | <?php |
| 2 | /* |
| 3 | Class names are changed to avoid duplication. |
| 4 | The class name has been changed from ReallySimpleCaptcha to CloudSecureWP_ReallySimpleCaptcha. |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * Plugin Name: Really Simple CAPTCHA |
| 9 | * Plugin URI: https://contactform7.com/captcha/ |
| 10 | * Description: Really Simple CAPTCHA is a CAPTCHA module intended to be called from other plugins. It is originally created for my Contact Form 7 plugin. |
| 11 | * Author: Takayuki Miyoshi |
| 12 | * Author URI: https://ideasilo.wordpress.com/ |
| 13 | * License: GPL v2 or later |
| 14 | * License URI: https://www.gnu.org/licenses/gpl-2.0.html |
| 15 | * Version: 2.2 |
| 16 | * Requires at least: 6.1 |
| 17 | * Requires PHP: 7.4 |
| 18 | */ |
| 19 | |
| 20 | define( 'CLOUDSECUREWP_REALLYSIMPLECAPTCHA_VERSION', '2.2' ); |
| 21 | |
| 22 | class CloudSecureWP_ReallySimpleCaptcha { |
| 23 | |
| 24 | public $chars; |
| 25 | public $char_length; |
| 26 | public $fonts; |
| 27 | public $tmp_dir; |
| 28 | public $img_size; |
| 29 | public $bg; |
| 30 | public $fg; |
| 31 | public $base; |
| 32 | public $font_size; |
| 33 | public $font_char_width; |
| 34 | public $img_type; |
| 35 | public $file_mode; |
| 36 | public $answer_file_mode; |
| 37 | |
| 38 | public function __construct() { |
| 39 | /* Characters available in images */ |
| 40 | $this->chars = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789'; |
| 41 | |
| 42 | /* Length of a word in an image */ |
| 43 | $this->char_length = 4; |
| 44 | |
| 45 | /* Array of fonts. Randomly picked up per character */ |
| 46 | $this->fonts = array( |
| 47 | path_join( __DIR__, 'gentium/GenBkBasR.ttf' ), |
| 48 | path_join( __DIR__, 'gentium/GenBkBasI.ttf' ), |
| 49 | path_join( __DIR__, 'gentium/GenBkBasBI.ttf' ), |
| 50 | path_join( __DIR__, 'gentium/GenBkBasB.ttf' ), |
| 51 | ); |
| 52 | |
| 53 | /* Directory temporary keeping CAPTCHA images and corresponding text files */ |
| 54 | $this->tmp_dir = path_join( __DIR__, 'tmp' ); |
| 55 | |
| 56 | /* Array of CAPTCHA image size. Width and height */ |
| 57 | $this->img_size = array( 72, 24 ); |
| 58 | |
| 59 | /* Background color of CAPTCHA image. RGB color 0-255 */ |
| 60 | $this->bg = array( 255, 255, 255 ); |
| 61 | |
| 62 | /* Foreground (character) color of CAPTCHA image. RGB color 0-255 */ |
| 63 | $this->fg = array( 0, 0, 0 ); |
| 64 | |
| 65 | /* Coordinates for a text in an image. I don't know the meaning. Just adjust. */ |
| 66 | $this->base = array( 6, 18 ); |
| 67 | |
| 68 | /* Font size */ |
| 69 | $this->font_size = 14; |
| 70 | |
| 71 | /* Width of a character */ |
| 72 | $this->font_char_width = 15; |
| 73 | |
| 74 | /* Image type. 'png', 'gif' or 'jpeg' */ |
| 75 | $this->img_type = 'png'; |
| 76 | |
| 77 | /* Mode of temporary image files */ |
| 78 | $this->file_mode = 0644; |
| 79 | |
| 80 | /* Mode of temporary answer text files */ |
| 81 | $this->answer_file_mode = 0640; |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Generate and return a random word. |
| 86 | * |
| 87 | * @return string Random word with $chars characters x $char_length length |
| 88 | */ |
| 89 | public function generate_random_word() { |
| 90 | $word = ''; |
| 91 | |
| 92 | for ( $i = 0; $i < $this->char_length; $i++ ) { |
| 93 | $pos = mt_rand( 0, strlen( $this->chars ) - 1 ); |
| 94 | $char = $this->chars[$pos]; |
| 95 | $word .= $char; |
| 96 | } |
| 97 | |
| 98 | return $word; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Generate CAPTCHA image and corresponding answer file. |
| 103 | * |
| 104 | * @param string $prefix File prefix used for both files |
| 105 | * @param string $word Random word generated by generate_random_word() |
| 106 | * @return string|bool The file name of the CAPTCHA image. Return false if temp directory is not available. |
| 107 | */ |
| 108 | public function generate_image( $prefix, $word ) { |
| 109 | if ( ! $this->make_tmp_dir() ) { |
| 110 | return false; |
| 111 | } |
| 112 | |
| 113 | $this->cleanup(); |
| 114 | |
| 115 | $dir = trailingslashit( $this->tmp_dir ); |
| 116 | $filename = null; |
| 117 | |
| 118 | $im = imagecreatetruecolor( |
| 119 | $this->img_size[0], |
| 120 | $this->img_size[1] |
| 121 | ); |
| 122 | |
| 123 | if ( $im ) { |
| 124 | $bg = imagecolorallocate( $im, $this->bg[0], $this->bg[1], $this->bg[2] ); |
| 125 | $fg = imagecolorallocate( $im, $this->fg[0], $this->fg[1], $this->fg[2] ); |
| 126 | |
| 127 | imagefill( $im, 0, 0, $bg ); |
| 128 | |
| 129 | $x = $this->base[0] + mt_rand( -2, 2 ); |
| 130 | |
| 131 | for ( $i = 0; $i < strlen( $word ); $i++ ) { |
| 132 | $font = $this->fonts[array_rand( $this->fonts )]; |
| 133 | $font = wp_normalize_path( $font ); |
| 134 | |
| 135 | imagettftext( |
| 136 | $im, $this->font_size, mt_rand( -12, 12 ), $x, |
| 137 | $this->base[1] + mt_rand( -2, 2 ), $fg, $font, $word[$i] |
| 138 | ); |
| 139 | |
| 140 | $x += $this->font_char_width; |
| 141 | } |
| 142 | |
| 143 | switch ( $this->img_type ) { |
| 144 | case 'jpeg': |
| 145 | $filename = sanitize_file_name( $prefix . '.jpeg' ); |
| 146 | $file = wp_normalize_path( path_join( $dir, $filename ) ); |
| 147 | imagejpeg( $im, $file ); |
| 148 | break; |
| 149 | case 'gif': |
| 150 | $filename = sanitize_file_name( $prefix . '.gif' ); |
| 151 | $file = wp_normalize_path( path_join( $dir, $filename ) ); |
| 152 | imagegif( $im, $file ); |
| 153 | break; |
| 154 | case 'png': |
| 155 | default: |
| 156 | $filename = sanitize_file_name( $prefix . '.png' ); |
| 157 | $file = wp_normalize_path( path_join( $dir, $filename ) ); |
| 158 | imagepng( $im, $file ); |
| 159 | } |
| 160 | |
| 161 | imagedestroy( $im ); |
| 162 | @chmod( $file, $this->file_mode ); |
| 163 | } |
| 164 | |
| 165 | $this->generate_answer_file( $prefix, $word ); |
| 166 | |
| 167 | return $filename; |
| 168 | } |
| 169 | |
| 170 | /** |
| 171 | * Generate answer file corresponding to CAPTCHA image. |
| 172 | * |
| 173 | * @param string $prefix File prefix used for answer file |
| 174 | * @param string $word Random word generated by generate_random_word() |
| 175 | */ |
| 176 | public function generate_answer_file( $prefix, $word ) { |
| 177 | $dir = trailingslashit( $this->tmp_dir ); |
| 178 | $answer_file = path_join( $dir, sanitize_file_name( $prefix . '.txt' ) ); |
| 179 | $answer_file = wp_normalize_path( $answer_file ); |
| 180 | |
| 181 | if ( $fh = @fopen( $answer_file, 'w' ) ) { |
| 182 | $word = strtoupper( $word ); |
| 183 | $salt = wp_generate_password( 64 ); |
| 184 | $hash = hash_hmac( 'md5', $word, $salt ); |
| 185 | $code = $salt . '|' . $hash; |
| 186 | fwrite( $fh, $code ); |
| 187 | fclose( $fh ); |
| 188 | } |
| 189 | |
| 190 | @chmod( $answer_file, $this->answer_file_mode ); |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * Check a response against the code kept in the temporary file. |
| 195 | * |
| 196 | * @param string $prefix File prefix used for both files |
| 197 | * @param string $response CAPTCHA response |
| 198 | * |
| 199 | * @return bool Return true if the two match, otherwise return false. |
| 200 | */ |
| 201 | public function check( string $prefix, string $response ): bool { |
| 202 | if ( 0 === strlen( $prefix ) ) { |
| 203 | return false; |
| 204 | } |
| 205 | |
| 206 | $response = str_replace( array( " ", "\t" ), '', $response ); |
| 207 | $response = strtoupper( $response ); |
| 208 | |
| 209 | $dir = trailingslashit( $this->tmp_dir ); |
| 210 | $filename = sanitize_file_name( $prefix . '.txt' ); |
| 211 | $file = wp_normalize_path( path_join( $dir, $filename ) ); |
| 212 | |
| 213 | if ( is_readable( $file ) |
| 214 | and $code = file_get_contents( $file ) ) { |
| 215 | $code = explode( '|', $code, 2 ); |
| 216 | $salt = $code[0]; |
| 217 | $hash = $code[1]; |
| 218 | |
| 219 | if ( hash_equals( $hash, hash_hmac( 'md5', $response, $salt ) ) ) { |
| 220 | return true; |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | return false; |
| 225 | } |
| 226 | |
| 227 | /** |
| 228 | * Remove temporary files with given prefix. |
| 229 | * |
| 230 | * @param string $prefix File prefix |
| 231 | */ |
| 232 | public function remove( $prefix ) { |
| 233 | $dir = trailingslashit( $this->tmp_dir ); |
| 234 | $suffixes = array( '.jpeg', '.gif', '.png', '.php', '.txt' ); |
| 235 | |
| 236 | foreach ( $suffixes as $suffix ) { |
| 237 | $filename = sanitize_file_name( $prefix . $suffix ); |
| 238 | $file = wp_normalize_path( path_join( $dir, $filename ) ); |
| 239 | |
| 240 | if ( is_file( $file ) ) { |
| 241 | @unlink( $file ); |
| 242 | } |
| 243 | } |
| 244 | } |
| 245 | |
| 246 | /** |
| 247 | * Clean up dead files older than given length of time. |
| 248 | * |
| 249 | * @param int $minutes Consider older files than this time as dead files |
| 250 | * @return int|bool The number of removed files. Return false if error occurred. |
| 251 | */ |
| 252 | public function cleanup( $minutes = 60, $max = 100 ) { |
| 253 | $dir = trailingslashit( $this->tmp_dir ); |
| 254 | $dir = wp_normalize_path( $dir ); |
| 255 | |
| 256 | if ( ! is_dir( $dir ) |
| 257 | or ! is_readable( $dir ) ) { |
| 258 | return false; |
| 259 | } |
| 260 | |
| 261 | $is_win = ( 'WIN' === strtoupper( substr( PHP_OS, 0, 3 ) ) ); |
| 262 | |
| 263 | if ( ! ( $is_win ? win_is_writable( $dir ) : is_writable( $dir ) ) ) { |
| 264 | return false; |
| 265 | } |
| 266 | |
| 267 | $count = 0; |
| 268 | |
| 269 | if ( $handle = opendir( $dir ) ) { |
| 270 | while ( false !== ( $filename = readdir( $handle ) ) ) { |
| 271 | if ( ! preg_match( '/^[0-9]+\.(php|txt|png|gif|jpeg)$/', $filename ) ) { |
| 272 | continue; |
| 273 | } |
| 274 | |
| 275 | $file = wp_normalize_path( path_join( $dir, $filename ) ); |
| 276 | |
| 277 | if ( ! file_exists( $file ) |
| 278 | or ! $stat = stat( $file ) ) { |
| 279 | continue; |
| 280 | } |
| 281 | |
| 282 | if ( ( $stat['mtime'] + $minutes * MINUTE_IN_SECONDS ) < time() ) { |
| 283 | if ( ! @unlink( $file ) ) { |
| 284 | @chmod( $file, 0644 ); |
| 285 | @unlink( $file ); |
| 286 | } |
| 287 | |
| 288 | $count += 1; |
| 289 | } |
| 290 | |
| 291 | if ( $max <= $count ) { |
| 292 | break; |
| 293 | } |
| 294 | } |
| 295 | |
| 296 | closedir( $handle ); |
| 297 | } |
| 298 | |
| 299 | return $count; |
| 300 | } |
| 301 | |
| 302 | /** |
| 303 | * Make a temporary directory and generate .htaccess file in it. |
| 304 | * |
| 305 | * @return bool True on successful create, false on failure. |
| 306 | */ |
| 307 | public function make_tmp_dir() { |
| 308 | $dir = trailingslashit( $this->tmp_dir ); |
| 309 | $dir = wp_normalize_path( $dir ); |
| 310 | |
| 311 | if ( ! wp_mkdir_p( $dir ) ) { |
| 312 | return false; |
| 313 | } |
| 314 | |
| 315 | $htaccess_file = wp_normalize_path( path_join( $dir, '.htaccess' ) ); |
| 316 | |
| 317 | if ( file_exists( $htaccess_file ) ) { |
| 318 | list( $first_line_comment ) = (array) file( |
| 319 | $htaccess_file, |
| 320 | FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES |
| 321 | ); |
| 322 | |
| 323 | if ( '# Apache 2.4+' === $first_line_comment ) { |
| 324 | return true; |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | if ( $handle = @fopen( $htaccess_file, 'w' ) ) { |
| 329 | fwrite( $handle, "# Apache 2.4+\n" ); |
| 330 | fwrite( $handle, "<IfModule authz_core_module>\n" ); |
| 331 | fwrite( $handle, " Require all denied\n" ); |
| 332 | fwrite( $handle, ' <FilesMatch "^\w+\.(jpe?g|gif|png)$">' . "\n" ); |
| 333 | fwrite( $handle, " Require all granted\n" ); |
| 334 | fwrite( $handle, " </FilesMatch>\n" ); |
| 335 | fwrite( $handle, "</IfModule>\n" ); |
| 336 | fwrite( $handle, "\n" ); |
| 337 | fwrite( $handle, "# Apache 2.2\n" ); |
| 338 | fwrite( $handle, "<IfModule !authz_core_module>\n" ); |
| 339 | fwrite( $handle, " Order deny,allow\n" ); |
| 340 | fwrite( $handle, " Deny from all\n" ); |
| 341 | fwrite( $handle, ' <FilesMatch "^\w+\.(jpe?g|gif|png)$">' . "\n" ); |
| 342 | fwrite( $handle, " Allow from all\n" ); |
| 343 | fwrite( $handle, " </FilesMatch>\n" ); |
| 344 | fwrite( $handle, "</IfModule>\n" ); |
| 345 | |
| 346 | fclose( $handle ); |
| 347 | } |
| 348 | |
| 349 | return true; |
| 350 | } |
| 351 | |
| 352 | } |
| 353 |