IBAN Check digits should always between 2 and 98

karstennilsen · karstennilsen · commit 855b714fab9a · 2024-05-14T14:30:22.000+02:00
A ECBS document (https://www.ecbs.org/Download/EBS204_V3.PDF) replicates part of the ISO/IEC 7064:2003 standard as a method for generating check digits in the range 02 to 98. Example of invalid IBANs, which before were valid, are NL01INGB0001393698 and NL01RABO0331811235. You can check them at iban.com to verify they are indeed invalid.
diff --git a/src/Symfony/Component/Validator/Constraints/IbanValidator.php b/src/Symfony/Component/Validator/Constraints/IbanValidator.php
@@ -228,6 +228,18 @@ public function validate($value, Constraint $constraint)
             return;
         }
 
+        // Check digits should always between 2 and 98
+        // A ECBS document (https://www.ecbs.org/Download/EBS204_V3.PDF) replicates part of the ISO/IEC 7064:2003 standard as a method for generating check digits in the range 02 to 98.
+        $checkDigits = (int) substr($canonicalized, 2, 4);
+        if ($checkDigits < 2 || $checkDigits > 98) {
+            $this->context->buildViolation($constraint->message)
+                ->setParameter('{{ value }}', $this->formatValue($value))
+                ->setCode(Iban::CHECKSUM_FAILED_ERROR)
+                ->addViolation();
+
+            return;
+        }
+
         // Move the first four characters to the end
         // e.g. CH93 0076 2011 6238 5295 7
         //   -> 0076 2011 6238 5295 7 CH93
diff --git a/src/Symfony/Component/Validator/Tests/Constraints/IbanValidatorTest.php b/src/Symfony/Component/Validator/Tests/Constraints/IbanValidatorTest.php
@@ -401,6 +401,12 @@ public static function getIbansWithValidFormatButIncorrectChecksum()
             ['UA213223130000026007233566002'], // Ukraine
             ['AE260211000000230064017'], // United Arab Emirates
             ['VA59001123000012345671'], // Vatican City State
+
+            // Checksum digits not between 02 and 98
+            ['FO00 5432 0388 8999 44'], // Faroe Islands
+            ['NL01INGB0001393698'], // Netherlands
+            ['NL01RABO0331811235'], // Netherlands
+            ['RU99 0445 2560 0407 0281 0412 3456 7890 1'], // Russia
         ];
     }
 
