Decode the allowed contract types in a TRON active permission

A permission can have enough signing weight while its operations bitmap excludes the requested action. Decode the bitmap before investigating missing signatures.

Map the protocol contract type to one bit

Read the selected active permission from the account. Use the TRON protocol’s numeric contract type identifiers. The example enables TransferContract (1) and DelegateResourceContract (57) in an otherwise empty 32-byte mask. Byte index starts at zero and the low bit of each byte comes first.

operations = bytearray(32)
for contract_id in (1, 57):
    operations[contract_id // 8] |= 1 << (contract_id % 8)
assert operations[0] == 0x02 and operations[7] == 0x02
print(operations.hex())

Test the intended denial as well as the allowance

The resulting mask permits native TRX transfers and resource delegation. It leaves TriggerSmartContract disabled, so calling a TRC-20 transfer method still fails under this permission. Verify the actual transaction’s permission ID and threshold separately. A bit enabling permission updates carries broader authority than a payment-only worker ordinarily requires.

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