Monero: add more legacy verify functions (#383)

* Add v1 ring sig verifying

* allow calculating signature hash for v1 txs

* add unreduced scalar type with recovery

I have added this type for borromen sigs, the ee field can be a normal
scalar as in the verify function the ee
field is checked against a reduced scalar mean for it to verify as
correct ee must be reduced

* change block major/ minor versions to u8

this matches Monero

I have also changed a couple varint functions to accept the `VarInt`
trait

* expose `serialize_hashable` on `Block`

* add back MLSAG verifying functions

I still need to revert the commit removing support for >1 input MLSAG FULL

This adds a new rct type to separate Full and simple rct

* add back support for multiple inputs for RCT FULL

* comment `non_adjacent_form` function

also added `#[allow(clippy::needless_range_loop)]` around a loop as without a re-write satisfying clippy without it will make the function worse.

* Improve Mlsag verifying API

* fix rebase errors

* revert the changes on `reserialize_chain`
plus other misc changes

* fix no-std

* Reduce the amount of rpc calls needed for `get_block_by_number`.
This function was causing me problems, every now and then a node would return a block with a different number than requested.

* change `serialize_hashable` to give the POW hashing blob.

Monero calculates the POW hash and the block hash using *slightly* different blobs :/

* make ring_signatures public and add length check when verifying.

* Misc improvements and bug fixes

---------

Co-authored-by: Luke Parker <lukeparker5132@gmail.com>

coins/monero/src/wallet/extra.rs

@@ -110,11 +110,7 @@ impl ExtraField {
         }
         nonce
       }),
-      3 => ExtraField::MergeMining(
-        usize::try_from(read_varint(r)?)
-          .map_err(|_| io::Error::new(io::ErrorKind::Other, "varint for height exceeds usize"))?,
-        read_bytes(r)?,
-      ),
+      3 => ExtraField::MergeMining(read_varint(r)?, read_bytes(r)?),
       4 => ExtraField::PublicKeys(read_vec(read_point, r)?),
       _ => Err(io::Error::new(io::ErrorKind::Other, "unknown extra field"))?,
     })

coins/monero/src/wallet/mod.rs

@@ -74,7 +74,7 @@ pub(crate) fn shared_key(
     .copy_from_slice(&hash(&[output_derivation.as_ref(), [0x8d].as_ref()].concat())[.. 8]);
 
   // || o
-  write_varint(&o.try_into().unwrap(), &mut output_derivation).unwrap();
+  write_varint(&o, &mut output_derivation).unwrap();
 
   let view_tag = hash(&[b"view_tag".as_ref(), &output_derivation].concat())[0];
 

coins/monero/src/wallet/send/multisig.rs

@@ -406,7 +406,9 @@ impl SignatureMachine<Transaction> for TransactionSignatureMachine {
           pseudo_outs.push(pseudo_out);
         }
       }
-      RctPrunable::MlsagBorromean { .. } | RctPrunable::MlsagBulletproofs { .. } => {
+      RctPrunable::AggregateMlsagBorromean { .. } |
+      RctPrunable::MlsagBorromean { .. } |
+      RctPrunable::MlsagBulletproofs { .. } => {
         unreachable!("attempted to sign a multisig TX which wasn't CLSAG")
       }
     }