Reading container file RSA certificates.

[cb0001]

Is the structure of the RSA certificate at the beginning of xbox 360 container files public knowledge? I've figured out (but tell me if I'm wrong) that the rsa exponent is the 4 bytes at offset 40 (65537, very common exponent).  I've also figured out that the encrypted signature is the 128 bytes at 428 (because by comparing files from my xbox, this is the only part that is different).  The 384 bytes between the exponent and the signature, I have no idea about though.  Public modulus? Anyways, if I could get a C structure for this that would be awesome.