Constants
SHA512_256_BLOCK_SIZE
uint256 constant SHA512_256_BLOCK_SIZE = 128;
PRECOMPILE_IDENTITY_ADDRESS
uint256 constant PRECOMPILE_IDENTITY_ADDRESS = 4;
HMAC_IPAD
bytes32 constant HMAC_IPAD = 0x3636363636363636363636363636363636363636363636363636363636363636;
HMAC_OPAD_XOR_IPAD
bytes32 constant HMAC_OPAD_XOR_IPAD = 0x6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a;