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Fix outputs digest in signature hash.

This commit is contained in:
Kris Nuttycombe 2021-01-21 17:23:09 -07:00
parent 56dd669368
commit c693ab88bd
1 changed files with 45 additions and 30 deletions
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zip-0244.rst
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@ -31,7 +31,7 @@ This proposal also defines a new transaction digest algorithm for signature vali
which shares all available structure produced during the construction of transaction
identifiers, in order to minimize redundant data hashing in validation.
This proposal also defines new semantics for the ``hashLightClientRoot`` field of the
This proposal also defines a new name and semantics for the ``hashLightClientRoot`` field of the
block header, to enable additional commitments to be represented in this hash and to
provide a mechanism for future extensibility of the set of commitments represented.
@ -371,10 +371,10 @@ S.2: ``transparent_digest``
`````````````````````````
If we are producing a hash for the signature over a transparent input,
the value of the digest produced here depends upon the value of a ``hash_type``
flag as in ZIP 143 [#zip-0143]_ and BIP 143 [#bip-0143]_.
flag as in ZIP 143 [#zip-0143]_.
The construction of each component below depends upon the values of the
hash_type flag bits. Each component will be described separately
``hash_type`` flag bits. Each component will be described separately
This digest is a BLAKE2b-256 hash of the following values ::
@ -392,42 +392,48 @@ S.2a: ``prevouts_digest``
This is a BLAKE2b-256 hash initialized with the personalization field value
"ZTxIdPrevoutHash".
If the ``SIGHASH_ANYONECANPAY`` flag is set::
* the hash is immediately finalized, without being updated with any
additional data
otherwise::
If the ``SIGHASH_ANYONECANPAY`` flag is not set::
* identical to the value of ``prevouts_digest`` as specified for the
transaction identifier in section T.2a.
otherwise::
* the hash is immediately finalized, without being updated with any
additional data
S.2b: ``sequence_digest``
'''''''''''''''''''''''
This is a BLAKE2b-256 hash initialized with the personalization field value
"ZTxIdSequencHash".
If any of the ``SIGHASH_ANYONECANPAY``, ``SIGHASH_SINGLE``, or ``SIGHASH_NONE`` flags are
If none of the ``SIGHASH_ANYONECANPAY``, ``SIGHASH_SINGLE``, or ``SIGHASH_NONE`` flags are
set::
* the hash is immediately finalized, without being updated with any
additional data
otherwise::
* identical to the value of ``sequence_digest`` as specified for the
transaction identifier in section T.2b.
otherwise::
* the hash is immediately finalized, without being updated with any
additional data
S.2c: ``outputs_digest``
'''''''''''''''''''''''
This is a BLAKE2b-256 hash initialized with the personalization field value
"ZTxIdOutputsHash".
If the ``SIGHASH_SINGLE`` flag is set and the signature hash is being computed for a
transparent input::
If none of the ``SIGHASH_SINGLE`` or ``SIGHASH_NONE`` flags are set::
* the hash is updated with the field encoding of the ``prevout`` field value
of the input, then finalized
* identical to the value of ``outputs_digest`` as specified for the
transaction identifier in section T.2c.
If the ``SIGHASH_SINGLE`` flag is set and the signature hash is being computed for
the transparent input at a particular index, and a transparent output appears in
the transaction at that index::
* the hash is updated with the transaction serialized form of the
transparent output at that index, and finalized.
If the ``SIGHASH_SINGLE`` flag is set and the signature is being computed for
a shielded input, or if the ``SIGHASH_NONE`` flag is set::
@ -435,11 +441,6 @@ a shielded input, or if the ``SIGHASH_NONE`` flag is set::
* the hash is immediately finalized, without being updated with any
additional data
otherwise::
* identical to the value of ``outputs_digest`` as specified for the
transaction identifier in section T.2c.
S.2d: ``txin_sig_digest``
'''''''''''''''''''''''''
This is a BLAKE2b-256 hash initialized with the personalization field value
@ -566,6 +567,21 @@ of the following elements::
* ``hashLightClientRoot`` as described in ZIP 221 [#zip-0221]_
* ``hashAuthDataRoot``
* ``terminator`` [0u8;32]
This representation treats the ``hashBlockCommitments`` value as a linked
list of hashes terminated by arbitrary data. In the case of protocol upgrades
where additional commitments need to be included in the block header, it is
possible to replace this terminator with the hash of a newly defined structure
which ends in a similar terminator. Fully validating nodes MUST always use the
entire structure defined by the latest activated protocol version that they
support.
The linked structure of this hash is intended to provide extensibility for
use by light clients which may be connected to a third-party server that supports
a later protocol version. Such a third party SHOULD provide a value that can
be used instead of the all-zeros terminator to permit the light client to
perform validation of the parts of the structure it needs.
========================
@ -579,10 +595,9 @@ References
==========
.. [#RFC2119] `RFC 2119: Key words for use in RFCs to Indicate Requirement Levels <https://www.rfc-editor.org/rfc/rfc2119.html>`_
.. [#zip-0200] `ZIP 200: Network Upgrade Activation Mechanism <https://zips.z.cash/zip-0200>`_
.. [#zip-0221] `ZIP 221: FlyClient - Consensus Layer Changes <https://zips.z.cash/zip-0221>`_
.. [#zip-0076] `ZIP 76: Transaction Signature Validation before Overwinter <https://zips.z.cash/zip-0076>`_
.. [#zip-0143] `ZIP 143: Transaction Signature Validation for Overwinter <https://zips.z.cash/zip-0143>`_
.. [#bip-0143] `Transaction Signature Verification for Version 0 Witness Program <https://github.com/bitcoin/bips/blob/master/bip-0143.mediawiki>`_
.. [#zip-0307] `ZIP 307: Light Client Protocol for Payment Detection <https://zips.z.cash/zip-0307>`_
.. [#zip-0200] `ZIP 200: Network Upgrade Activation Mechanism <zip-0200.rst>`_
.. [#zip-0221] `ZIP 221: FlyClient - Consensus Layer Changes <zip-0221.rst>`_
.. [#zip-0076] `ZIP 76: Transaction Signature Validation before Overwinter <zip-0076.rst>`_
.. [#zip-0143] `ZIP 143: Transaction Signature Validation for Overwinter <zip-0143.rst>`_
.. [#zip-0307] `ZIP 307: Light Client Protocol for Payment Detection <zip-0307.rst>`_