I know our community ed/adult ed branch has online classes for GED, but of course they are for Florida...
Might do better finding an actual accredited (ie, can give federal financial aid) community college in your area that offers teh same... at least you know that way there is some oversight from your regional accreditation board.
A quick google shows Bunker Hill CC (bhcc.edu) has online classes for GED prep (although Mass. just changed the name from GED to HiSET -
Test Prep and some more googling shows that they are indeed accredited....