diff vendor/symfony/validator/Constraints/LuhnValidator.php @ 0:c75dbcec494b

Initial commit from drush-created site

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/symfony/validator/Constraints/LuhnValidator.php	Thu Jul 05 14:24:15 2018 +0000
@@ -0,0 +1,96 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[e-mail]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Validator\Constraints;
+
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+
+/**
+ * Validates a PAN using the LUHN Algorithm.
+ *
+ * For a list of example card numbers that are used to test this
+ * class, please see the LuhnValidatorTest class.
+ *
+ * @see    http://en.wikipedia.org/wiki/Luhn_algorithm
+ *
+ * @author Tim Nagel <[e-mail]>
+ * @author Greg Knapp http://gregk.me/2011/php-implementation-of-bank-card-luhn-algorithm/
+ * @author Bernhard Schussek <[e-mail]>
+ */
+class LuhnValidator extends ConstraintValidator
+{
+    /**
+     * Validates a credit card number with the Luhn algorithm.
+     *
+     * @param mixed      $value
+     * @param Constraint $constraint
+     *
+     * @throws UnexpectedTypeException when the given credit card number is no string
+     */
+    public function validate($value, Constraint $constraint)
+    {
+        if (!$constraint instanceof Luhn) {
+            throw new UnexpectedTypeException($constraint, __NAMESPACE__.'\Luhn');
+        }
+
+        if (null === $value || '' === $value) {
+            return;
+        }
+
+        // Work with strings only, because long numbers are represented as floats
+        // internally and don't work with strlen()
+        if (!is_string($value) && !(is_object($value) && method_exists($value, '__toString'))) {
+            throw new UnexpectedTypeException($value, 'string');
+        }
+
+        $value = (string) $value;
+
+        if (!ctype_digit($value)) {
+            $this->context->buildViolation($constraint->message)
+                ->setParameter('{{ value }}', $this->formatValue($value))
+                ->setCode(Luhn::INVALID_CHARACTERS_ERROR)
+                ->addViolation();
+
+            return;
+        }
+
+        $checkSum = 0;
+        $length = strlen($value);
+
+        // Starting with the last digit and walking left, add every second
+        // digit to the check sum
+        // e.g. 7  9  9  2  7  3  9  8  7  1  3
+        //      ^     ^     ^     ^     ^     ^
+        //    = 7  +  9  +  7  +  9  +  7  +  3
+        for ($i = $length - 1; $i >= 0; $i -= 2) {
+            $checkSum += $value[$i];
+        }
+
+        // Starting with the second last digit and walking left, double every
+        // second digit and add it to the check sum
+        // For doubles greater than 9, sum the individual digits
+        // e.g. 7  9  9  2  7  3  9  8  7  1  3
+        //         ^     ^     ^     ^     ^
+        //    =    1+8 + 4  +  6  +  1+6 + 2
+        for ($i = $length - 2; $i >= 0; $i -= 2) {
+            $checkSum += array_sum(str_split($value[$i] * 2));
+        }
+
+        if (0 === $checkSum || 0 !== $checkSum % 10) {
+            $this->context->buildViolation($constraint->message)
+                ->setParameter('{{ value }}', $this->formatValue($value))
+                ->setCode(Luhn::CHECKSUM_FAILED_ERROR)
+                ->addViolation();
+        }
+    }
+}