[SDS-3136] Add Japan driving license checksum

sds/src/scanner/regex_rule/config.rs

@@ -248,6 +248,7 @@ pub enum SecondaryValidator {
     IbanChecker,
     IrishPpsChecksum,
     ItalianNationalIdChecksum,
+    JapanDrivingLicenseChecksum,
     JwtClaimsValidator {
         config: JwtClaimsValidatorConfig,
     },

sds/src/secondary_validation/japan_driving_license_checksum.rs

@@ -0,0 +1,104 @@
+use crate::secondary_validation::{Validator, validate_mod11_weighted_checksum};
+
+/// [NPA §1(4)](https://www.npa.go.jp/laws/notification/menkyo20250310_76.pdf) confirms modulus 11,
+/// but omits weights and remainder handling. This implementation combines secondary sources:
+/// [WDIC](https://www.wdic.org/w/GEO/運転免許証) (weights and remainder handling) and
+/// [Resource Sharing](https://resource-sharing.co.jp/driver-license-number-check-digit/)
+/// (matching weights and a worked example); their independence is unverified.
+///
+/// Sources disagree on remainder 0: a [Delphix example](https://help.delphix.com/dcs/current/content/docs/japan_drivers_license.htm)
+/// implies check digit 0. We choose 1, following WDIC and
+/// [Fujii's explicit rule](https://ameblo.jp/fujiikenzi-shihousyoshi/entry-12957415231.html).
+pub struct JapanDrivingLicenseChecksum;
+
+const WEIGHTS: [u32; 10] = [5, 4, 3, 2, 7, 6, 5, 4, 3, 2];
+
+impl Validator for JapanDrivingLicenseChecksum {
+    fn is_valid_match(&self, regex_match: &str) -> bool {
+        let digits = regex_match.as_bytes();
+        if digits.len() != 12 || !digits.iter().all(u8::is_ascii_digit) {
+            return false;
+        }
+
+        // The final digit is the reissuance indicator, not part of the checksum.
+        validate_mod11_weighted_checksum(&regex_match[..11], &WEIGHTS, |remainder| {
+            Some((11 - remainder) % 10)
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const VALID_EXAMPLES: [&str; 3] = [
+        "309212345690", // Worked example: https://resource-sharing.co.jp/driver-license-number-check-digit/
+        "155261998521", // Masked output: https://help.delphix.com/dcs/current/content/docs/japan_drivers_license.htm
+        "897346134533", // Masked output: https://help.delphix.com/dcs/current/content/docs/japan_drivers_license.htm
+    ];
+
+    #[test]
+    fn accepts_published_examples() {
+        for number in VALID_EXAMPLES {
+            assert!(
+                JapanDrivingLicenseChecksum.is_valid_match(number),
+                "expected published example to pass: {number}"
+            );
+        }
+    }
+
+    #[test]
+    fn rejects_corrupted_check_digits() {
+        for number in VALID_EXAMPLES {
+            for check_digit in b'0'..=b'9' {
+                if check_digit == number.as_bytes()[10] {
+                    continue;
+                }
+                let mut corrupted = number.as_bytes().to_vec();
+                corrupted[10] = check_digit;
+                let corrupted = String::from_utf8(corrupted).unwrap();
+                assert!(
+                    !JapanDrivingLicenseChecksum.is_valid_match(&corrupted),
+                    "expected corrupted check digit to fail: {corrupted}"
+                );
+            }
+        }
+    }
+
+    #[test]
+    fn rejects_corrupted_data_digits() {
+        for number in VALID_EXAMPLES {
+            for index in 0..10 {
+                let mut corrupted = number.as_bytes().to_vec();
+                corrupted[index] = b'0' + (corrupted[index] - b'0' + 1) % 10;
+                let corrupted = String::from_utf8(corrupted).unwrap();
+                assert!(
+                    !JapanDrivingLicenseChecksum.is_valid_match(&corrupted),
+                    "expected corrupted data digit to fail: {corrupted}"
+                );
+            }
+        }
+    }
+
+    #[test]
+    fn rejects_malformed_input() {
+        for input in [
+            "",
+            "30921234569",
+            "3092123456900",
+            "30921234569X",
+            "X09212345690",
+            " 309212345690",
+            "309212345690 ",
+            "3092 1234 5690",
+            "3092-1234-5690",
+            "３０９２１２３４５６９０",
+            "30921234569０",
+        ] {
+            assert!(
+                !JapanDrivingLicenseChecksum.is_valid_match(input),
+                "expected malformed input to fail: {input:?}"
+            );
+        }
+    }
+}

sds/src/secondary_validation/mod.rs

@@ -29,6 +29,7 @@ mod iban_checker;
 mod irish_pps_checksum;
 mod iso_7064_checksum;
 mod italian_national_id_checksum;
+mod japan_driving_license_checksum;
 pub mod jwt_claims_validator;
 mod jwt_expiration_checker;
 mod latvia_national_id_checksum;
@@ -100,6 +101,7 @@ pub use crate::secondary_validation::iso_7064_checksum::{
     Mod97_10checksum, Mod661_26checksum, Mod1271_36Checksum,
 };
 pub use crate::secondary_validation::italian_national_id_checksum::ItalianNationalIdChecksum;
+pub use crate::secondary_validation::japan_driving_license_checksum::JapanDrivingLicenseChecksum;
 pub use crate::secondary_validation::jwt_claims_validator::JwtClaimsValidator;
 pub use crate::secondary_validation::jwt_expiration_checker::JwtExpirationChecker;
 pub use crate::secondary_validation::latvia_national_id_checksum::LatviaNationalIdChecksum;
@@ -247,6 +249,9 @@ impl SecondaryValidator {
             SecondaryValidator::IbanChecker => Arc::new(IbanChecker),
             SecondaryValidator::IrishPpsChecksum => Arc::new(IrishPpsChecksum),
             SecondaryValidator::ItalianNationalIdChecksum => Arc::new(ItalianNationalIdChecksum),
+            SecondaryValidator::JapanDrivingLicenseChecksum => {
+                Arc::new(JapanDrivingLicenseChecksum)
+            }
             SecondaryValidator::JwtClaimsValidator { config } => {
                 Arc::new(JwtClaimsValidator::new(config.clone()))
             }