gistfile1.pl

    my $public_key = <<__END_OF_PUBLIC__;
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDASPndWVBy/VYe99aVM/5PWVdS
D3Vb5uAlK4cAPz091V/1SOeL3YSRuOposPMDjf5TlQuUr/TmNE6cbAUFV0hLFQuB
69KmJN+Bt8JwptFbuFetNKaMVESntg69+VPeuvuqo2+Ob7dcTXnvNxTfdJcwga9f
W5Af9jh82kQTWmZf5QIDAQAB
-----END PUBLIC KEY-----
__END_OF_PUBLIC__

    my $verifier = OAuth::Lite::SignatureMethod::RSA_SHA1->new(
        consumer_secret => $public_key,
    );

    my $params = $c->req->params;
    my $oauth_signature = $params->{oauth_signature};
    delete $params->{oauth_signature};
$c->log->debug($params);

    my $base_string = create_signature_base_string($c->req->method, 'http://example.jp/test_for_opensocial', $params );

    my $result = $verifier->verify($base_string, $oauth_signature);