ethereum.forks.dao_fork.vm.precompiled_contracts.sha256ethereum.forks.tangerine_whistle.vm.precompiled_contracts.sha256

Ethereum Virtual Machine (EVM) SHA256 PRECOMPILED CONTRACT.

.. contents:: Table of Contents :backlinks: none :local:

Introduction

Implementation of the SHA256 precompiled contract.

sha256

Writes the sha256 hash to output.

Parameters

evm : The current EVM frame.

def sha256(​evm: Evm​) -> None:
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    <snip>
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    data = evm.message.data
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    # GAS
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    word_count = ceil32(ulen(data)) // Uint(32)
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    charge_gas(
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        evm,
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        GasCosts.PRECOMPILE_SHA256_BASE
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        + GasCosts.PRECOMPILE_SHA256_PER_WORD * word_count,
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    )
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    # OPERATION
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    evm.output = hashlib.sha256(data).digest()