0.4.0

Added

• Wallet which allows users to select coins through a backend configured by them via the GetUtxos trait.
  The provided wallet comes with a UTXO cache which this is updated using Wallet::sync.
  This allows users of the library to optimise the number of requests to their backend.
  Users can also sign said UTXOs by calling Wallet::sign.
• Timelock type to allow users of the library to explicitly choose the type of timelock they want to use when building the loan transaction.
  For the time being, users can still pass in a u32, but they are encouraged not to.

Changed

• The borrower can now choose the collateral inputs before calling Borrower0::new.

Fixed

• The loan transaction no longer expects collateral and principal change outputs.
  We were unconditionally adding them to the transaction which could result in attempting to build a 0-valued confidential transaction output, which is invalid.**

0.3.0

Added

• Chain on which the loan protocol takes place is no longer hard-coded to Elements (local development node).
  The chain is implicitly configured by the addresses that are passed in.
  Furthermore, the protocol now verifies that borrower and lender are on the same chain.
• New API build_loan_transaction on Lender0, which wraps the now deprecated interpret:
  • The lender now has direct control over the principal_amount, principal_inputs, repayment_amount and min_collateral_price.

Fixed

• Always satisfy the collateral contract input in the loan repayment transaction correctly.
  We used to assume that it was located at index 1, but this could change if the number of inputs used to cover the repayment output was greater than 1.

Changed

• Lender sets collateral contract timelock, as opposed to the borrower.
• Deprecated all APIs which use LoanRequest, to give users more control over how they want to serialize the parameters inside loan request.

0.2.0

Added

• Dynamic liquidation branch to the loan protocol:
  • New async fn dynamic_liquidation_transaction() API on Lender1.
    It takes a message of the form price:timestamp and an oracle's signature on the hash of the message, so that a lender can unilaterally liquidate the loan if the price falls below a threshold and the timestamp is past a certain time.
  • Lender0 constructor now requires blinding key of lender address and an oracle public key.

Changed

• loan::LoanResponse fields:
  • Made timelock private, but accessible via LoanResponse::collateral_contract(&self).timelock().
  • Made transaction private, accessible via getter.
  • Made collateral_amount private, but accessible via getter.
• loan::Borrower1 fields:
  • Made loan_transaction private, but accessible via getter.
  • Made collateral_amount private, but accessible via getter.
• loan::Lender1 fields:
  • Made timelock private, but accessible via getter.
• fn liquidation_transaction() API on Lender1 is now async.
• Model the collateral contract's timelock as a u32.

Fixed

• Squashed an elusive bug preventing users from building version 0.1.0 of this library.
  This required updating rust-elements to version 0.18.

0.1.0

Added

• Loan protocol and swap libraries originally developed in Project Waves.