keyczar_util.js
function _rsaHash(publicKey) {
    var md = forge.md.sha1.create();

    // hash:
    // 4-byte big endian length
    // "magnitude" of the public modulus (trim all leading zero bytes)
    // same for the exponent
    _hashBigNumber(md, publicKey.n);
    _hashBigNumber(md, publicKey.e);
    var digest = md.digest();
    return digest.getBytes(keyczar_util.KEYHASH_LENGTH);
}
function _rsaHash(publicKey) {
    var md = forge.md.sha1.create();

    // hash:
    // 4-byte big endian length
    // "magnitude" of the public modulus (trim all leading zero bytes)
    // same for the exponent
    _hashBigNumber(md, publicKey.n);
    _hashBigNumber(md, publicKey.e);
    var digest = md.digest();
    return digest.getBytes(keyczar_util.KEYHASH_LENGTH);
}
Returns the keyhash for an RSA public key.