blockchains-security-toolkit/vulnerabilities/security_tips.md

🌭 security tips

• tx.origin needs to bere placed by msg.sender, otherwise any contract you call can act on your behalf.
• inline assembly should be used only in rare cases.
• unclear semantics: now is alias for block.timestamp not current time; use of low level call, callcode, delegatecall should be avoided whenever possible; use transfer whenever failure of ether transfer should rollnack the whole transaction.
• beware of caller contracts: selfdestruct can block calling contracts unexpectedly.
• invocation of local functions via this: never use this to call functions in the same contract, it only consumes more gas than normal call.
• transferring Ether in a for/while/do-while loop should be avoid due to the block gas limit.
• erc20 decimals should have uint8 as return type.