`verify` cannot handle illegally padded signatures because it takes an object
of type `Signature`, which is a fixed-size type. This should have been part
of the previous commit --- an important lesson about running the unit tests
before every push!
I was trying to do something clever by making sure that the numeric
bounds were consistent with whatever ordering relation we were checking,
AND that the boolean values were also consistent...this is Wrong is the
case of negative numbers, and pointless anyway since I recently fixed
`set_bool_value`, `set_num_lo` and `set_num_hi` to update both numeric
and boolean information if possible, so they will always contain the
same info.
Now unspendable outs are determined by attempting to create a minimal
satisfying input script. If this can't be done, the output is unspendable.
(Unfortunately this "minimal satisfying script" is not (yet) something
that can be shown to the user, since it is more a bundle of constraints
than actual data pushes.)
Current limitations:
- OP_ADD and friends mean the checker gives the script a free pass.
There is no fundamental reason for this, I just didn't get to it
yet.
- Pubkeys are checked for DER encoding but signatures aren't. This
is because secp256k1 exposes a method for pubkeys, but not one
for sigs :). Signatures are loosely length checked.
Looks like to implement the crypto opcodes I may need to switch from
rust-crypto to rust-openssl.. or implement RIPEMD-160 for rust-crypto.
In either case I will need to generalize the hash.rs stuff to support
other hashes, so I'm committing here as a checkpoint before doing all
that.
This is a massive simplification, fixes a couple endianness bugs (though
not all of them I don't think), should give a speedup, gets rid of the
`serialize_iter` crap.
I think this is what I want to do for everything json-visible...perhaps
I will not be able to keep the macro for it though, since there are
some clever variations on it (e.g. blocks should have their header's
hash as a field, txes should appear as txids unless vebose output is
requested, etc.)
Andrew Poelstra