Compute ECDSA modular inverses with Fermal's Little Theorem. am: 1f170d0b00 am: 10c2234fb3 am: 77658a7f05 am: 14b44d83f2  -s ours am: 714afb8f3d am: a968399736 am: 1b75e28e6e am: b47a4aea2e am: 2e6898e9b4
am: 5aa84b72d3

Change-Id: I8284c45663ced46311b597409b709a2bad79b7a9