1 files changed, 179 insertions, 0 deletions
diff --git a/www/wiki/extensions/OATHAuth/includes/lib/hotp.php b/www/wiki/extensions/OATHAuth/includes/lib/hotp.php
new file mode 100644
index 00000000..8fd3d94b
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+++ b/www/wiki/extensions/OATHAuth/includes/lib/hotp.php
@@ -0,0 +1,179 @@
+<?php
+/**
+ * HOTP Class
+ * Based on the work of OAuth, and the sample implementation of HMAC OTP
+ * http://tools.ietf.org/html/draft-mraihi-oath-hmac-otp-04#appendix-D
+ * @author Jakob Heuser (firstname)@felocity.com
+ * @copyright 2011
+ * @license BSD-3-Clause
+ * @version 1.0
+ */
+class HOTP {
+	/**
+	 * Generate a HOTP key based on a counter value (event based HOTP)
+	 * @param string $key the key to use for hashing
+	 * @param int $counter the number of attempts represented in this hashing
+	 * @return HOTPResult a HOTP Result which can be truncated or output
+	 */
+	public static function generateByCounter( $key, $counter ) {
+		// the counter value can be more than one byte long,
+		// so we need to pack it down properly.
+		$cur_counter = array( 0, 0, 0, 0, 0, 0, 0, 0 );
+		for ( $i = 7; $i >= 0; $i-- ) {
+			$cur_counter[$i] = pack( 'C*', $counter );
+			$counter = $counter >> 8;
+		}
+
+		$bin_counter = implode( $cur_counter );
+
+		// Pad to 8 chars
+		if ( strlen( $bin_counter ) < 8 ) {
+			$bin_counter = str_repeat( "\0", 8 - strlen( $bin_counter ) ) . $bin_counter;
+		}
+
+		// HMAC
+		$hash = hash_hmac( 'sha1', $bin_counter, $key );
+
+		return new HOTPResult( $hash );
+	}
+
+	/**
+	 * Generate a HOTP key based on a timestamp and window size
+	 *
+	 * @param string $key the key to use for hashing
+	 * @param int $window the size of the window a key is valid for in seconds
+	 * @param int|bool $timestamp a timestamp to calculate for, defaults to time()
+	 *
+	 * @return HOTPResult a HOTP Result which can be truncated or output
+	 */
+	public static function generateByTime( $key, $window, $timestamp = false ) {
+		if ( !$timestamp && $timestamp !== 0 ) {
+			$timestamp = HOTP::getTime();
+		}
+
+		$counter = (int)( $timestamp / $window );
+
+		return HOTP::generateByCounter( $key, $counter );
+	}
+
+	/**
+	 * Generate a HOTP key collection based on a timestamp and window size
+	 * all keys that could exist between a start and end time will be included
+	 * in the returned array
+	 *
+	 * @param string $key the key to use for hashing
+	 * @param int $window the size of the window a key is valid for in seconds
+	 * @param int $min the minimum window to accept before $timestamp
+	 * @param int $max the maximum window to accept after $timestamp
+	 * @param int|bool $timestamp a timestamp to calculate for, defaults to time()
+	 *
+	 * @return HOTPResult[]
+	 */
+	public static function generateByTimeWindow( $key, $window, $min = -1,
+		$max = 1, $timestamp = false
+	) {
+		if ( !$timestamp && $timestamp !== 0 ) {
+			$timestamp = HOTP::getTime();
+		}
+
+		$counter = (int)( $timestamp / $window );
+		$window = range( $min, $max );
+
+		$out = array();
+		$length = count( $window );
+		for ( $i = 0; $i < $length; $i++ ) {
+			$shift_counter = $counter + $window[$i];
+			$out[$shift_counter] = HOTP::generateByCounter($key, $shift_counter);
+		}
+
+		return $out;
+	}
+
+	/**
+	 * Gets the current time
+	 * Ensures we are operating in UTC for the entire framework
+	 * Restores the timezone on exit.
+	 * @return int the current time
+	 */
+	public static function getTime() {
+		return time(); // PHP's time is always UTC
+	}
+}
+
+/**
+ * The HOTPResult Class converts an HOTP item to various forms
+ * Supported formats include hex, decimal, string, and HOTP
+ * @author Jakob Heuser (firstname)@felocity.com
+ */
+class HOTPResult {
+	protected $hash;
+	protected $binary;
+	protected $decimal;
+	protected $hex;
+
+	/**
+	 * Build an HOTP Result
+	 * @param string $value the value to construct with
+	 */
+	public function __construct( $value ) {
+		// store raw
+		$this->hash = $value;
+
+		// store calculate decimal
+		$hmac_result = array();
+
+		// Convert to decimal
+		foreach ( str_split( $this->hash, 2 ) as $hex ) {
+			$hmac_result[] = hexdec($hex);
+		}
+
+		$offset = $hmac_result[19] & 0xf;
+
+		$this->decimal = (
+			( ( $hmac_result[$offset+0] & 0x7f ) << 24 ) |
+			( ( $hmac_result[$offset+1] & 0xff ) << 16 ) |
+			( ( $hmac_result[$offset+2] & 0xff ) << 8 ) |
+			( $hmac_result[$offset+3] & 0xff )
+		);
+
+		// calculate hex
+		$this->hex = dechex( $this->decimal );
+	}
+
+	/**
+	 * Returns the string version of the HOTP
+	 * @return string
+	 */
+	public function toString() {
+		return $this->hash;
+	}
+
+	/**
+	 * Returns the hex version of the HOTP
+	 * @return string
+	 */
+	public function toHex() {
+		return $this->hex;
+	}
+
+	/**
+	 * Returns the decimal version of the HOTP
+	 * @return int
+	 */
+	public function toDec() {
+		return $this->decimal;
+	}
+
+	/**
+	 * Returns the truncated decimal form of the HOTP
+	 * @param int $length the length of the HOTP to return
+	 * @return string
+	 */
+	public function toHOTP( $length ) {
+		$str = str_pad( $this->toDec(), $length, "0", STR_PAD_LEFT );
+		$str = substr( $str, ( -1 * $length ) );
+
+		return $str;
+	}
+
+}