Validator for "Clave Bancaria Uniforme", or CBU, as used in the Argentinean banking system

cbuvalidator.js

/**
 * Validator and brute-force checksum generator for "Clave Bancaria Uniforme"
 * fromat used in the Argentinan banking system.
 *
 * Legal stuff at http://www.infoleg.gob.ar/infolegInternet/anexos/45000-49999/47564/norma.htm
 * Code based on https://gist.github.com/delucas/4526176
 * Universal loader based on https://gist.github.com/jrburke/1262861
 */

/* global define, window */

(function (define) {

    var cbuValidator = {};

    // Validation error codes
    cbuValidator.errorCode = {
        "OK": 0,
        "BAD_LENGTH": 1,
        "BAD_BANKBRANCH": 2,
        "BAD_ACCOUNT": 3
    };

    // Validate CBU code length
    cbuValidator.validateCBULength = function (cbu) {
        return cbu.length === 22;
    };

    // Validate the bank/branch section of a CBU
    cbuValidator.validateBankBranch = function (code) {
        if (code.length != 8) {
            return false;
        }
        var bank = code.substr(0, 3),
            checksum1 = code[3],
            branch = code.substr(4, 3),
            checksum2 = code[7],
            sum = bank[0] * 7 + bank[1] * 1 + bank[2] * 3 +
                checksum1 * 9 + branch[0] * 7 + branch[1] * 1 + branch[2] * 3,
            diff = 10 - (sum % 10);
        return diff == checksum2;
    };

    // Validate the account section of a CBU
    cbuValidator.validateAccount = function (num) {
        if (num.length != 14) {
            return false;
        }
        var checksum = num[13],
            sum = num[0] * 3 +
                num[1] * 9 + num[2] * 7 + num[3] * 1 + num[4] * 3 +
                num[5] * 9 + num[6] * 7 + num[7] * 1 + num[8] * 3 +
                num[9] * 9 + num[10] * 7 + num[11] * 1 + num[12] * 3,
            diff = 10 - (sum % 10);
        return diff == checksum;
    };

    // Validate a CBU code
    cbuValidator.validateCBU = function (cbu) {
        if (cbuValidator.validateCBULength(cbu)) {
            if (cbuValidator.validateBankBranch(cbu.substr(0, 8))) {
                if (cbuValidator.validateAccount(cbu.substr(8, 14))) {
                    return cbuValidator.errorCode.OK;
                } else {
                    return cbuValidator.errorCode.BAD_ACCOUNT;
                }
            } else {
                return cbuValidator.errorCode.BAD_BANKBRANCH;
            }
        } else {
            return cbuValidator.errorCode.BAD_LENGTH;
        }
    };

    // Tiny brute force bank + branch + checksums generator
    cbuValidator.getBankBranchCode = function (bank, branch) {
        if (bank.length !== 3 || branch.length !== 3) {
            return null;
        }
        for (var ck1 = 0; ck1 < 10; ck1++) {
            for (var ck2 = 0; ck2 < 10; ck2++) {
                var code = bank + ck1 + branch + ck2;
                if (cbuValidator.validateBankBranch(code)) {
                    return code;
                }
            }
        }
    };

    // Tiny brute force account + checksum generator
    cbuValidator.getAccountCode = function (account) {
        if (account.length !== 13) {
            return null;
        }
        for (var ck = 0; ck < 10; ck++) {
            var code = account + ck;
            if (cbuValidator.validateAccount(code)) {
                return code;
            }
        }
    };

    // expose module interface
    define("cbuValidator", function () {
        return cbuValidator;
    });

})(typeof define === "function" && define.amd ? define : function (id, factory) {
    if (typeof module !== "undefined" && module.exports) {
        // Node.js
        module.exports = factory();
    } else {
        // Create a global function
        window[id] = factory();
    }
});