migrate-nomatch-alglen: switched to RSASHA256 instead of RSASHA1
and the key size now changes from 2048 bits to 3072 bits instead
of 1024 bits to 2048 bits.
migrate-nomatch-algnum: switched to RSASHA256 instead of RSASHA1
as initial algorithm and adjusted mininum key size to 2048 bits.
rsasha256: adjusted minimum key size to 2048 bits.