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Merged
ConstanceBeguier merged 5 commits into from
Nov 3, 2025
Merged

Add versioned signatures for Transparent transactions #35

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ed11a21
Add sigash version to binding sig only when the binding sig exists
ConstanceBeguier Oct 29, 2025
a5b081b
Add sighash info for transparent transaction
ConstanceBeguier Oct 29, 2025
f3d9ef6
Update test vectors
ConstanceBeguier Oct 29, 2025
ad136bd
Refactor
ConstanceBeguier Oct 29, 2025
66d3e24
Refactor
ConstanceBeguier Nov 3, 2025
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18 changes: 9 additions & 9 deletions test-vectors/json/orchard_zsa_digests.json
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4,846 changes: 2,423 additions & 2,423 deletions test-vectors/rust/orchard_zsa_digests.rs
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18 changes: 9 additions & 9 deletions test-vectors/zcash/orchard_zsa_digests.json
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4 changes: 4 additions & 0 deletions zcash_test_vectors/transaction.py
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Original file line number Diff line number Diff line change
Expand Up @@ -499,6 +499,10 @@ def to_bytes(self, version_bytes, nVersionGroupId, nConsensusBranchId):
ret += write_compact_size(len(self.vout))
for x in self.vout:
ret += bytes(x)
if version_bytes == NU7_TX_VERSION_BYTES:
for sighash_info in self.vSighashInfo:
ret += write_compact_size(len(sighash_info))
ret += bytes(sighash_info)

# Sapling Transaction Fields
hasSapling = len(self.vSpendsSapling) + len(self.vOutputsSapling) > 0
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8 changes: 5 additions & 3 deletions zcash_test_vectors/transaction_v6.py
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Expand Up @@ -149,11 +149,13 @@ def __init__(self, rand, consensus_branch_id, sighash_info, have_orchard_zsa=Tru

# All Transparent, Sapling, and part of the Orchard Transaction Fields are initialized in the super class.
super().__init__(rand, have_orchard_zsa)
self.vSighashInfo = [sighash_info] * len(self.vin)
for desc in self.vSpendsSapling:
desc.spendAuthSigInfo = sighash_info
self.bindingSigSaplingInfo = sighash_info
self.bindingSigOrchardInfo = sighash_info

if hasattr(self, "bindingSigSapling"):
self.bindingSigSaplingInfo = sighash_info
if hasattr(self, "bindingSigOrchard"):
self.bindingSigOrchardInfo = sighash_info
Comment on lines +155 to +158
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@PaulLaux PaulLaux Nov 2, 2025

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Later, in

        for desc in tx.vOutputsSapling:
            digest.update(bytes(desc.proof))
        digest.update(write_compact_size(len(tx.bindingSigSaplingInfo)))
        digest.update(bytes(tx.bindingSigSaplingInfo))
        digest.update(bytes(tx.bindingSigSapling))

what happens if tx.bindingSigSaplingInfo in None?

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@ConstanceBeguier ConstanceBeguier Nov 3, 2025 •
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def sapling_auth_digest_v6(tx):
    digest = blake2b(digest_size=32, person=SAPLING_AUTH_DIGEST_PERSONALIZAION)

    if len(tx.vSpendsSapling) + len(tx.vOutputsSapling) > 0:
        for desc in tx.vSpendsSapling:
            digest.update(bytes(desc.proof))
        for desc in tx.vSpendsSapling:
            digest.update(write_compact_size(len(desc.spendAuthSigInfo)))
            digest.update(bytes(desc.spendAuthSigInfo))
            digest.update(bytes(desc.spendAuthSig))
        for desc in tx.vOutputsSapling:
            digest.update(bytes(desc.proof))
        digest.update(write_compact_size(len(tx.bindingSigSaplingInfo)))
        digest.update(bytes(tx.bindingSigSaplingInfo))
        digest.update(bytes(tx.bindingSigSapling))

    return digest.digest()

If tx.bindingSigSaplingInfo is None and we try to access it, an exception will be raised.
The function sapling_auth_digest_v6 is only called for v6 transaction.
In this function, tx.bindingSigSaplingInfo and tx.bindingSigSapling are accessed only when the transaction includes a Sapling element.
For v6 transactions, whenever a Sapling element is present, both of these fields are populated.


# Common Transaction Fields
self.nVersionGroupId = NU7_VERSION_GROUP_ID
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15 changes: 13 additions & 2 deletions zcash_test_vectors/zip_0244.py
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Original file line number Diff line number Diff line change
Expand Up @@ -41,12 +41,22 @@ def transparent_digest(tx):

return digest.digest()

TRANSPARENT_AUTH_DIGEST_PERSONALIZAION = b'ZTxAuthTransHash'

def transparent_scripts_digest(tx):
digest = blake2b(digest_size=32, person=b'ZTxAuthTransHash')
digest = blake2b(digest_size=32, person=TRANSPARENT_AUTH_DIGEST_PERSONALIZAION)
for x in tx.vin:
digest.update(bytes(x.scriptSig))
return digest.digest()

def transparent_scripts_digest_v6(tx):
digest = blake2b(digest_size=32, person=TRANSPARENT_AUTH_DIGEST_PERSONALIZAION)
for (sighash_info, vin) in zip(tx.vSighashInfo, tx.vin):
digest.update(write_compact_size(len(sighash_info)))
digest.update(bytes(sighash_info))
digest.update(bytes(vin.scriptSig))
return digest.digest()

# Sapling

def sapling_digest(tx):
Expand Down Expand Up @@ -243,12 +253,13 @@ def auth_digest(tx):
person=b'ZTxAuthHash_' + struct.pack('<I', tx.nConsensusBranchId),
)

digest.update(transparent_scripts_digest(tx))
if tx.version_bytes() == NU7_TX_VERSION_BYTES:
digest.update(transparent_scripts_digest_v6(tx))
digest.update(sapling_auth_digest_v6(tx))
digest.update(orchard_zsa_auth_digest(tx))
digest.update(issuance_auth_digest(tx))
else:
digest.update(transparent_scripts_digest(tx))
digest.update(sapling_auth_digest(tx))
digest.update(orchard_auth_digest(tx))

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