This PR makes two major changs to ct-fetch. First we verify the entries that we download against the internal nodes of the CT log's Merkle tree. This "check-summing" will ultimately let us import entries from a source other than the CT log itself. The second commit changes the order in which we download log entries. Reverse order is preferable if we're going to import a large cache of entries from a third party.
This PR makes two major changs to ct-fetch. First we verify the entries that we download against the internal nodes of the CT log's Merkle tree. This "check-summing" will ultimately let us import entries from a source other than the CT log itself. The second commit changes the order in which we download log entries. Reverse order is preferable if we're going to import a large cache of entries from a third party.