BIP 385: raw() and addr() Output Script Descriptors

  BIP: 385
  Layer: Applications
  Title: raw() and addr() Output Script Descriptors
  Authors: Pieter Wuille <[email protected]>
           Ava Chow <[email protected]>
  Status: Deployed
  Type: Informational
  Assigned: 2021-06-27
  License: BSD-2-Clause
  Requires: 380

Abstract

This document specifies raw() and addr() output script descriptors. raw() encapsulates a raw script as a descriptor. addr() encapsulates an address as a descriptor.

Copyright

This BIP is licensed under the BSD 2-clause license.

Motivation

In order to make descriptors maximally compatible with scripts in use today, it is useful to be able to wrap any arbitrary output script or an address into a descriptor.

Specification

Two new script expressions are defined: raw() and addr().

`raw()`

The raw(HEX) expression can only be used as a top level descriptor. As the argument, it takes a hex string representing a Bitcoin script. The output script produced by this descriptor is the script represented by HEX.

`addr()`

The addr(ADDR) expression can only be used as a top level descriptor. It takes an address as its single argument. The output script produced by this descriptor is the output script produced by the address ADDR.

Test Vectors

Valid descriptors followed by the scripts they produce.

raw(deadbeef)
- deadbeef
raw(512103a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd4104a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd5b8dec5235a0fa8722476c7709c02559e3aa73aa03918ba2d492eea75abea23552ae)
- 512103a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd4104a34b99f22c790c4e36b2b3c2c35a36db06226e41c692fc82b8b56ac1c540c5bd5b8dec5235a0fa8722476c7709c02559e3aa73aa03918ba2d492eea75abea23552ae
raw(a9149a4d9901d6af519b2a23d4a2f51650fcba87ce7b87)
- a9149a4d9901d6af519b2a23d4a2f51650fcba87ce7b87
addr(3PUNyaW7M55oKWJ3kDukwk9bsKvryra15j)
- a914eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee87

Invalid descriptors

Non-hex script: raw(asdf)
Invalid address: addr(asdf)
raw nested in sh: sh(raw(deadbeef))
raw nested in wsh: wsh(raw(deadbeef))
addr nested in sh: sh(addr(3PUNyaW7M55oKWJ3kDukwk9bsKvryra15j))
addr nested in wsh: wsh(addr(3PUNyaW7M55oKWJ3kDukwk9bsKvryra15j))

Backwards Compatibility

raw() and addr() descriptors use the format and general operation specified in 380. As this is a wholly new descriptor, it is not compatible with any implementation. The reuse of existing Bitcoin addresses allows for this to be more easily implemented.

Reference Implementation

raw() and addr() descriptors have been implemented in Bitcoin Core since version 0.17.