class-nif-validator.php

<?php

class NIF_Validator
{
    /**
     * @var string
     */
    private $number = null;
    /**
     * @var bool
     */
    private $acceptCIF;
    /**
     * @var bool
     */
    private $acceptDNI;
    /**
     * @var bool
     */
    private $acceptNIE;

    public function __construct($number, $acceptDNI = false, $acceptNIE = false, $acceptCIF = false)
    {
        $this->number = strtoupper($number);
        $this->acceptDNI = $acceptDNI;
        $this->acceptNIE = $acceptNIE;
        $this->acceptCIF = $acceptCIF;
    }

    public function isValid()
    {
        if ($this->acceptDNI && self::isValidDNI($this->number)) {
            return true;
        }
        if ($this->acceptNIE && self::isValidNIE($this->number)) {
            return true;
        }
        if ($this->acceptCIF && self::isValidCIF($this->number)) {
            return true;
        }
        return false;
    }
    // NIF validation functions below this line are Copyright (C) 2013 Amnesty International and licensed under the terms of the GNU General Public License version 3 as published by the Free Software Foundation.

    /*
    *   This function validates a Spanish identification number
    *   verifying its check digits.
    *
    *   NIFs and NIEs are personal numbers.
    *   CIFs are corporates.
    *
    *   This function requires:
    *       - isValidCIF and isValidCIFFormat
    *       - isValidNIE and isValidNIEFormat
    *       - isValidDNI and isValidDNIFormat
    *
    *   This function returns:
    *       TRUE: If specified identification number is correct
    *       FALSE: Otherwise
    *
    *   Usage:
    *       echo isValidIdNumber( 'G28667152' );
    *   Returns:
    *       TRUE
    */
    public static function isValidIdNumber($docNumber)
    {
        $fixedDocNumber = strtoupper($docNumber);
        return self::isValidDNI($fixedDocNumber) || self::isValidNIE($fixedDocNumber) || self::isValidCIF($fixedDocNumber);
    }

    /*
      *   This function validates a Spanish identification number
      *   verifying its check digits.
      *
      *   This function is intended to work with NIF numbers.
      *
      *   This function is used by:
      *       - isValidIdNumber
      *
      *   This function requires:
      *       - isValidCIFFormat
      *       - $this->getNIFCheckDigit
      *
      *   This function returns:
      *       TRUE: If specified identification number is correct
      *       FALSE: Otherwise
      *
      *   Algorithm works as described in:
      *       http://www.interior.gob.es/dni-8/calculo-del-digito-de-Check-del-nif-nie-2217
      *
      *   Usage:
      *       echo isValidDNI( '33576428Q' );
      *   Returns:
      *       TRUE
      */
    public static function isValidDNI($docNumber)
    {
        $isValid = FALSE;
        $fixedDocNumber = "";

        $correctDigit = "";
        $writtenDigit = "";

        if (!preg_match("/^[A-Z]+$/i", substr($fixedDocNumber, 1, 1))) {
            $fixedDocNumber = strtoupper(substr("000000000" . $docNumber, -9));
        } else {
            $fixedDocNumber = strtoupper($docNumber);
        }

        $writtenDigit = strtoupper(substr($docNumber, -1, 1));

        if (self::isValidDNIFormat($fixedDocNumber)) {
            $correctDigit = self::getNIFCheckDigit($fixedDocNumber);

            if ($writtenDigit == $correctDigit) {
                $isValid = TRUE;
            }
        }

        return $isValid;
    }

    /*
      *   This function validates a Spanish identification number
      *   verifying its check digits.
      *
      *   This function is intended to work with NIE numbers.
      *
      *   This function is used by:
      *       - isValidIdNumber
      *
      *   This function requires:
      *       - isValidNIEFormat
      *       - isValidDNI
      *
      *   This function returns:
      *       TRUE: If specified identification number is correct
      *       FALSE: Otherwise
      *
      *   Algorithm works as described in:
      *       http://www.interior.gob.es/dni-8/calculo-del-digito-de-control-del-nif-nie-2217
      *
      *   Usage:
      *       echo isValidNIE( 'X6089822C' )
      *   Returns:
      *       TRUE
      */
    public static function isValidNIE($docNumber)
    {
        $isValid = FALSE;
        $fixedDocNumber = "";

        if (!preg_match("/^[A-Z]+$/i", substr($fixedDocNumber, 1, 1))) {
            $fixedDocNumber = strtoupper(substr("000000000" . $docNumber, -9));
        } else {
            $fixedDocNumber = strtoupper($docNumber);
        }

        if (self::isValidNIEFormat($fixedDocNumber)) {
            if (substr($fixedDocNumber, 1, 1) == "T") {
                $isValid = TRUE;
            } else {
                /* The algorithm for validating the check digits of a NIE number is
                      identical to the altorithm for validating NIF numbers. We only have to
                      replace Y, X and Z with 1, 0 and 2 respectively; and then, run
                      the NIF altorithm */
                $numberWithoutLast = substr($fixedDocNumber, 0, strlen($fixedDocNumber) - 1);
                $lastDigit = substr($fixedDocNumber, strlen($fixedDocNumber) - 1, strlen($fixedDocNumber));
                $numberWithoutLast = str_replace('Y', '1', $numberWithoutLast);
                $numberWithoutLast = str_replace('X', '0', $numberWithoutLast);
                $numberWithoutLast = str_replace('Z', '2', $numberWithoutLast);
                $fixedDocNumber = $numberWithoutLast . $lastDigit;
                $isValid = self::isValidDNI($fixedDocNumber);
            }
        }

        return $isValid;
    }

    /*
      *   This function validates a Spanish identification number
      *   verifying its check digits.
      *
      *   This function is intended to work with CIF numbers.
      *
      *   This function is used by:
      *       - isValidDoc
      *
      *   This function requires:
      *       - isValidCIFFormat
      *       - getCIFCheckDigit
      *
      *   This function returns:
      *       TRUE: If specified identification number is correct
      *       FALSE: Otherwise
      *
      * CIF numbers structure is defined at:
      *   BOE number 49. February 26th, 2008 (article 2)
      *
      *   Usage:
      *       echo isValidCIF( 'F43298256' );
      *   Returns:
      *       TRUE
      */
    public static function isValidCIF($docNumber)
    {
        $isValid = FALSE;
        $fixedDocNumber = "";

        $correctDigit = "";
        $writtenDigit = "";

        $fixedDocNumber = strtoupper($docNumber);
        $writtenDigit = substr($fixedDocNumber, -1, 1);

        if (self::isValidCIFFormat($fixedDocNumber) == 1) {
            $correctDigit = self::getCIFCheckDigit($fixedDocNumber);

            if ($writtenDigit == $correctDigit) {
                $isValid = TRUE;
            }
        }

        return $isValid;
    }


    /*
      *   This function obtains the description of a document type
      *   for Spanish identification number.
      *
      *   For instance, if A83217281 is passed, it returns "Sociedad Anónima".
      *
      *   This function requires:
      *       - identificationType (table)
      *       - isValidCIFFormat
      *       - isValidNIEFormat
      *       - isValidDNIFormat
      *
      *   Usage:
      *       echo getIdType( 'A49640873' )
      *   Returns:
      *       Sociedad Anónima
      */

    private static $identificationType = array(
        'K' => 'Español menor de catorce años o extranjero menor de dieciocho',
        'L' => 'Español mayor de catorce años residiendo en el extranjero',
        'M' => 'Extranjero mayor de dieciocho años sin NIE',

        '0' => 'Español con documento nacional de identidad',
        '1' => 'Español con documento nacional de identidad',
        '2' => 'Español con documento nacional de identidad',
        '3' => 'Español con documento nacional de identidad',
        '4' => 'Español con documento nacional de identidad',
        '5' => 'Español con documento nacional de identidad',
        '6' => 'Español con documento nacional de identidad',
        '7' => 'Español con documento nacional de identidad',
        '8' => 'Español con documento nacional de identidad',
        '9' => 'Español con documento nacional de identidad',

        'T' => 'Extranjero residente en España e identificado por la Policía con un NIE',
        'X' => 'Extranjero residente en España e identificado por la Policía con un NIE',
        'Y' => 'Extranjero residente en España e identificado por la Policía con un NIE',
        'Z' => 'Extranjero residente en España e identificado por la Policía con un NIE',

        /* As described in BOE number 49. February 26th, 2008 (article 3) */
        'A' => 'Sociedad Anónima',
        'B' => 'Sociedad de responsabilidad limitada',
        'C' => 'Sociedad colectiva',
        'D' => 'Sociedad comanditaria',
        'E' => 'Comunidad de bienes y herencias yacentes',
        'F' => 'Sociedad cooperativa',
        'G' => 'Asociación',
        'H' => 'Comunidad de propietarios en régimen de propiedad horizontal',
        'J' => 'Sociedad Civil => con o sin personalidad jurídica',
        'N' => 'Entidad extranjera',
        'P' => 'Corporación local',
        'Q' => 'Organismo público',
        'R' => 'Congregación o Institución Religiosa',
        'S' => 'Órgano de la Administración del Estado y Comunidades Autónomas',
        'U' => 'Unión Temporal de Empresas',
        'V' => 'Fondo de inversiones o de pensiones, agrupación de interés económico, etc',
        'W' => 'Establecimiento permanente de entidades no residentes en España'
    );

    public static function getIdType($docNumber)
    {
        $docTypeDescription = "";
        $firstChar = substr($docNumber, 0, 1);

        if (
            self::isValidDNIFormat($docNumber) or
            self::isValidNIEFormat($docNumber) or
            self::isValidCIFFormat($docNumber)
        ) {

            $docTypeDescription = self::$identificationType[$firstChar];
        }

        return $docTypeDescription;
    }

    /*
      *   This function validates the format of a given string in order to
      *   see if it fits with NIF format. Practically, it performs a validation
      *   over a NIF, except this function does not check the check digit.
      *
      *   This function is intended to work with NIF numbers.
      *
      *   This function is used by:
      *       - isValidIdNumber
      *       - isValidDNI
      *
      *   This function returns:
      *       TRUE: If specified string respects NIF format
      *       FALSE: Otherwise
      *
      *   Usage:
      *       echo isValidDNIFormat( '33576428Q' )
      *   Returns:
      *       TRUE
      */
    private static function isValidDNIFormat($docNumber)
    {
        return self::respectsDocPattern(
            $docNumber,
            '/^[KLM0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][a-zA-Z0-9]/'
        );
    }

    /*
      *   This function validates the format of a given string in order to
      *   see if it fits with NIE format. Practically, it performs a validation
      *   over a NIE, except this function does not check the check digit.
      *
      *   This function is intended to work with NIE numbers.
      *
      *   This function is used by:
      *       - isValidIdNumber
      *       - isValidNIE
      *
      *   This function requires:
      *       - respectsDocPattern
      *
      *   This function returns:
      *       TRUE: If specified string respects NIE format
      *       FALSE: Otherwise
      *
      *   Usage:
      *       echo isValidNIEFormat( 'X6089822C' )
      *   Returns:
      *       TRUE
      */
    private static function isValidNIEFormat($docNumber)
    {
        return self::respectsDocPattern(
            $docNumber,
            '/^[XYZT][0-9][0-9][0-9][0-9][0-9][0-9][0-9][A-Z0-9]/'
        );
    }

    /*
      *   This function validates the format of a given string in order to
      *   see if it fits with CIF format. Practically, it performs a validation
      *   over a CIF, but this function does not check the check digit.
      *
      *   This function is intended to work with CIF numbers.
      *
      *   This function is used by:
      *       - isValidIdNumber
      *       - isValidCIF
      *
      *   This function requires:
      *       - respectsDocPattern
      *
      *   This function returns:
      *       TRUE: If specified string respects CIF format
      *       FALSE: Otherwise
      *
      *   Usage:
      *       echo isValidCIFFormat( 'H24930836' )
      *   Returns:
      *       TRUE
      */
    private static function isValidCIFFormat($docNumber)
    {
        return
            self::respectsDocPattern(
                $docNumber,
                '/^[PQSNWR][0-9][0-9][0-9][0-9][0-9][0-9][0-9][A-Z0-9]/'
            )
            or
            self::respectsDocPattern(
                $docNumber,
                '/^[ABCDEFGHJUV][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]/'
            );
    }

    /*
      *   This function calculates the check digit for an individual Spanish
      *   identification number (NIF).
      *
      *   You can replace check digit with a zero when calling the function.
      *
      *   This function is used by:
      *       - isValidDNI
      *
      *   This function requires:
      *       - isValidDNIFormat
      *
      *   This function returns:
      *       - Returns check digit if provided string had a correct NIF structure
      *       - An empty string otherwise
      *
      *   Usage:
      *       echo $this->getNIFCheckDigit( '335764280' )
      *   Returns:
      *       Q
      */
    private static function getNIFCheckDigit($docNumber)
    {
        $keyString = 'TRWAGMYFPDXBNJZSQVHLCKE';

        $fixedDocNumber = "";

        $position = 0;
        $writtenLetter = "";
        $correctLetter = "";

        if (!preg_match("/^[A-Z]+$/i", substr($fixedDocNumber, 1, 1))) {
            $fixedDocNumber = strtoupper(substr("000000000" . $docNumber, -9));
        } else {
            $fixedDocNumber = strtoupper($docNumber);
        }

        if (self::isValidDNIFormat($fixedDocNumber)) {
            $writtenLetter = substr($fixedDocNumber, -1);

            if (self::isValidDNIFormat($fixedDocNumber)) {
                $fixedDocNumber = str_replace('K', '0', $fixedDocNumber);
                $fixedDocNumber = str_replace('L', '0', $fixedDocNumber);
                $fixedDocNumber = str_replace('M', '0', $fixedDocNumber);

                $position = substr($fixedDocNumber, 0, 8) % 23;
                $correctLetter = substr($keyString, $position, 1);
            }
        }

        return $correctLetter;
    }

    /*
      *   This function calculates the check digit for a corporate Spanish
      *   identification number (CIF).
      *
      *   You can replace check digit with a zero when calling the function.
      *
      *   This function is used by:
      *       - isValidCIF
      *
      *   This function requires:
      *     - isValidCIFFormat
      *
      *   This function returns:
      *       - The correct check digit if provided string had a
      *         correct CIF structure
      *       - An empty string otherwise
      *
      *   Usage:
      *       echo getCIFCheckDigit( 'H24930830' );
      *   Prints:
      *       6
      */
    private static function getCIFCheckDigit($docNumber)
    {
        $fixedDocNumber = "";

        $centralChars = "";
        $firstChar = "";

        $evenSum = 0;
        $oddSum = 0;
        $totalSum = 0;
        $lastDigitTotalSum = 0;

        $correctDigit = "";

        $fixedDocNumber = strtoupper($docNumber);

        if (self::isValidCIFFormat($fixedDocNumber)) {
            $firstChar = substr($fixedDocNumber, 0, 1);
            $centralChars = substr($fixedDocNumber, 1, 7);

            $evenSum =
                substr($centralChars, 1, 1) +
                substr($centralChars, 3, 1) +
                substr($centralChars, 5, 1);

            $oddSum =
                self::sumDigits(substr($centralChars, 0, 1) * 2) +
                self::sumDigits(substr($centralChars, 2, 1) * 2) +
                self::sumDigits(substr($centralChars, 4, 1) * 2) +
                self::sumDigits(substr($centralChars, 6, 1) * 2);

            $totalSum = $evenSum + $oddSum;

            $lastDigitTotalSum = substr($totalSum, -1);

            if ($lastDigitTotalSum > 0) {
                $correctDigit = 10 - ($lastDigitTotalSum % 10);
            } else {
                $correctDigit = 0;
            }
        }

        /* If CIF number starts with P, Q, S, N, W or R,
              check digit sould be a letter */
        if (preg_match('/[PQSNWR]/', $firstChar)) {
            $correctDigit = substr("JABCDEFGHI", $correctDigit, 1);
        }

        return $correctDigit;
    }

    /*
      *   This function validates the format of a given string in order to
      *   see if it fits a regexp pattern.
      *
      *   This function is intended to work with Spanish identification
      *   numbers, so it always checks string length (should be 9) and
      *   accepts the absence of leading zeros.
      *
      *   This function is used by:
      *       - isValidDNIFormat
      *       - isValidNIEFormat
      *       - isValidCIFFormat
      *
      *   This function returns:
      *       TRUE: If specified string respects the pattern
      *       FALSE: Otherwise
      *
      *   Usage:
      *       echo respectsDocPattern(
      *           '33576428Q',
      *           '/^[KLM0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][A-Z]/' );
      *   Returns:
      *       TRUE
      */
    private static function respectsDocPattern($givenString, $pattern)
    {
        $isValid = FALSE;

        $fixedString = strtoupper($givenString);

        if (is_int(substr($fixedString, 0, 1))) {
            $fixedString = substr("000000000" . $givenString, -9);
        }

        if (preg_match($pattern, $fixedString)) {
            $isValid = TRUE;
        }

        return $isValid;
    }

    /*
      *   This function performs the sum, one by one, of the digits
      *   in a given quantity.
      *
      *   For instance, it returns 6 for 123 (as it sums 1 + 2 + 3).
      *
      *   This function is used by:
      *       - getCIFCheckDigit
      *
      *   Usage:
      *       echo sumDigits( 12345 );
      *   Returns:
      *       15
      */
    private static function sumDigits($digits)
    {
        $total = 0;
        $i = 1;

        while ($i <= strlen($digits)) {
            $thisNumber = substr($digits, $i - 1, 1);
            $total += $thisNumber;

            $i++;
        }

        return $total;
    }
}