Please keep in mind that the CCSDS document Xiao references is only a draft CCSDS recommendation, not the final recommendation. A few changes have been made since then. In the meantime, the G and H for all 10 of the LDPC codes have been verified.
The CCSDS specification gives the algorithm for generating G and H, but it does take some work to follow the directions.
For those interested in using or simulating the CCSDS LDPC codes, I am working to make full G and H files publicly available, so that people don't have to struggle with the standards document to derive these (large) matrices. In the meantime, if you contact me I can help you with access to them. In addition, full MATLAB encoder/decoder software is available (a C version is available as well)-- this code takes advantage of the circulant-based nature fo the code, so it is a bit more efficient than generic LDPC encoder/decoder that works with arbitrary parity matrices. This code is not public, but it can be licensed royalty free.