ci-bonfire / Sprint

		$opaque = md5(uniqid());

		// No digest string? Then you're done. Go home.

		if (empty($digest_string))

		{

			$this->ci->output->set_header( sprintf('WWW-Authenticate: Digest realm="%s", nonce="%s", opaque="%s"', config_item('api.realm'), $nonce, $opaque) );

			return false;

		}

		// Grab the parts from the digest string.

		// They will be provided as an array of the parts: username, nonce, uri, nc, cnonce, qop, response

		preg_match_all('@(username|nonce|uri|nc|cnonce|qop|response)=[\'"]?([^\'",]+)@', $digest_string, $matches);

		$digest = (empty($matches[1]) || empty($matches[2])) ? array() : array_combine($matches[1], $matches[2]);

		if (! array_key_exists('username', $digest))

		{

			$this->ci->output->set_header( sprintf('WWW-Authenticate: Digest realm="%s", nonce="%s", opaque="%s"', config_item('api.realm'), $nonce, $opaque) );

			return false;

		}

		// Set email for later throttling check

		if (config_item('api.auth_field') === 'email')

		}

		$valid_response = md5($A1 .':'. $digest['nonce'].':'. $digest['nc'] .':'. $digest['cnonce'] .':'. $digest['qop'] .':'. $A2);

		if ($digest['response'] != $valid_response)

		{

			$this->ci->output->set_header( sprintf('WWW-Authenticate: Digest realm="%s", nonce="%s", opaque="%s"', config_item('api.realm'), $nonce, $opaque) );

			return false;

		}

		$this->user = $user;