PKCS#12 : DerInputStream.getLength() exception

Question

I generate a certificate using the keytool command:

keytool -genkeypair -alias myRSAKey -keyalg RSA -keysize 1024 -keystore test.p12 -storepass test -storetype pkcs12

Then if I try to load it using java security API, after getting the file as a byte[] :

KeyStore ks = KeyStore.getInstance("PKCS12");
try{
   ks.load(new ByteArrayInputStream(data), "test".toCharArray())
} catch (Exception e){
   ...
}

I get a DerInputStream.getLength(): lengthTag=127, too big exception.

What is wrong?