ethereum.homestead.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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    """
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    Writes the sha256 hash to output.
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    Parameters
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    ----------
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    evm :
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        The current EVM frame.
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    """
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    data = evm.message.data
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    # GAS
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    word_count = ceil32(Uint(len(data))) // Uint(32)
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    charge_gas(evm, GAS_SHA256 + GAS_SHA256_WORD * word_count)
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    # OPERATION
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    evm.output = hashlib.sha256(data).digest()