txsort

README

txsort

Package txsort provides stable transaction sorting.

This package implements a standard lexicographical sort order of transaction inputs and outputs. This is useful to standardize transactions for faster multi-party agreement as well as preventing information leaks in a single-party use case. It is a modified form of BIP69 which has been updated to account for differences with Decred-specific transactions.

The sort order for transaction inputs is defined as follows:

• Previous transaction tree in ascending order
• Previous transaction hash (treated as a big-endian uint256) lexicographically in ascending order
• Previous output index in ascending order

The sort order for transaction outputs is defined as follows:

• Amount in ascending order
• Public key script version in ascending order
• Raw public key script bytes lexicographically in ascending order

A comprehensive suite of tests is provided to ensure proper functionality.

Installation and Updating

$ go get -u github.com/decred/dcrd/dcrutil/txsort

License

Package txsort is licensed under the copyfree ISC License.

Documentation

Overview

Package txsort provides stable transaction sorting.

Overview

This package implements a standard lexicographical sort order of transaction inputs and outputs. This is useful to standardize transactions for faster multi-party agreement as well as preventing information leaks in a single-party use case. It is a modified form of BIP69 which has been updated to account for differences with Decred-specific transactions.

The sort order for transaction inputs is defined as follows:

• Previous transaction tree in ascending order
• Previous transaction hash (treated as a big-endian uint256) lexicographically in ascending order
• Previous output index in ascending order

The sort order for transaction outputs is defined as follows: - Amount in ascending order - Public key script version in ascending order - Raw public key script bytes lexicographically in ascending order

Index

• func InPlaceSort(tx *wire.MsgTx)
• func IsSorted(tx *wire.MsgTx) bool
• func Sort(tx *wire.MsgTx) *wire.MsgTx

Functions

func InPlaceSort

func InPlaceSort(tx *wire.MsgTx)

InPlaceSort modifies the passed transaction inputs and outputs to be sorted according to the description in the package documentation.

WARNING: This function must NOT be called with published transactions since it will mutate the transaction if it's not already sorted. This can cause issues if you mutate a tx in a block, for example, which would invalidate the block. It could also cause cached hashes, such as in a dcrutil.Tx to become invalidated.

The function should only be used if the caller is creating the transaction or is otherwise 100% positive mutating will not cause adverse affects due to other dependencies.

func IsSorted

func IsSorted(tx *wire.MsgTx) bool

IsSorted checks whether tx has inputs and outputs sorted according to the description in the package documentation.

func Sort

func Sort(tx *wire.MsgTx) *wire.MsgTx

Sort returns a new transaction with the inputs and outputs sorted according to the description in the package documentation. The passed transaction is not modified and the new transaction might have a different hash if any sorting was done.