Validate a Ripple address in Python/JavaScript.

ripple.html

<!-- JavaScript is def. not batteries included. -->
<!-- From http://pastebin.com/B5r3P5Ny -->
<script src="http://crypto-js.googlecode.com/files/2.5.3-crypto-sha256.js"></script>
<script src="http://www-cs-students.stanford.edu/~tjw/jsbn/jsbn.js"></script>
<script src="http://www-cs-students.stanford.edu/~tjw/jsbn/jsbn2.js"></script>
<!-- taken from bitcoinjs almost verbatim -->
<script>
    BigInteger.valueOf = nbv;
    BigInteger.prototype.toByteArrayUnsigned = function () {
        var ba = this.toByteArray();
        if (ba.length) {
            if (ba[0] == 0)
                ba = ba.slice(1);
            return ba.map(function (v) {
                return (v < 0) ? v + 256 : v;
            });
        } else
            return ba;
    };
    var Ripple = {};
    (function () {
        var B58 = Ripple.Base58 = {
            alphabet: "rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz",
            base: BigInteger.valueOf(58),
          decode: function (input, minLength) {
            var bi = BigInteger.valueOf(0);
            for (var i=0; i < input.length; i++) {
              var alphaIndex = B58.alphabet.indexOf(input[i]);
              if (alphaIndex < 0)
                throw "Invalid character";
              bi = bi.multiply(B58.base).add(BigInteger.valueOf(alphaIndex));
            }
            var bytes = bi.toByteArrayUnsigned();
            while (bytes.length < minLength)
              bytes.unshift(0);
            return bytes;
          }
        };
    })();
    Ripple.Address = function (bytes) {
        if ("string" == typeof bytes)
            bytes = Ripple.Address.decodeString(bytes);
        this.hash = bytes;
    };
    Ripple.Address.decodeString = function (string) {
        var bytes = Ripple.Base58.decode(string, 25);
        var hash = bytes.slice(0, 21);
        var checksum = Crypto.SHA256(Crypto.SHA256(hash, { asBytes: true }), { asBytes: true });
        if (checksum[0] != bytes[21] ||
            checksum[1] != bytes[22] ||
            checksum[2] != bytes[23] ||
            checksum[3] != bytes[24])
            throw "Checksum validation failed!";
        var version = hash.shift();
        if (version != 0)
            throw "Version " + version + " not supported!";
        return hash;
    };
    function check_address(address) {
        try {
            Ripple.Address(address);
            return true;
        } catch (err) {
            console.log(err);
            return false;
        }
    }
</script>

ripple.py

def validate_ripple_address(str):
    # https://ripple.com/wiki/Accounts#Validating_Addresses
    # http://rosettacode.org/wiki/Bitcoin/address_validation#Python
    # http://stackoverflow.com/a/16022710/15677
    from hashlib import sha256
    digits58 = 'rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz'
    def to_bytes(n, length, endianess='big'):
        h = '%x' % n
        s = ('0'*(len(h) % 2) + h).zfill(length*2).decode('hex')
        return s if endianess == 'big' else s[::-1]
    def decode_base58(bc, length):
        n = 0
        for char in bc:
            n = n * 58 + digits58.index(char)
        return to_bytes(n, length, 'big')
    def check_bc(bc):
        try:
            bcbytes = decode_base58(bc, 25)
        except ValueError:
            return False
        return bcbytes[-4:] == sha256(sha256(bcbytes[:-4]).digest()).digest()[:4]
    return check_bc(str)

I have this error running the validate_ripple_address from ripple.py

s = ('0'(len(h) % 2) + h).zfill(length2).decode('hex')
AttributeError: 'str' object has no attribute 'decode'

I have the same issue as @alex75it

@alex75it @OptimusOpus
Changes below should fix it :)

import codecs
...

    def to_bytes(n, length, endianess='big'):
        h = '%x' % n
        s = codecs.decode(('0'*(len(h) % 2) + h).zfill(length*2), "hex_codec")
        return s if endianess == 'big' else s[::-1]