Genus Two subgroup to Matrices correspondence

Consdier an abelian variety, A, over a field of characteristic p, and given a prime l, this code wants to compute the matrices that correspond to subgroups of A[l]. Given an appropriate p, such that A[l] is Fp2-rational, the code can return all (l^2+1)*(l^2+l+1) matrices that correspond to all subgroups of A[l].