技巧1 使用注释扰乱分块数据包一些如Imperva、360等比较好的WAF已经对Transfer-Encoding的分块传输做了处理,可以把分块组合成完整的HTTP数据包,这时直接使用常规的分块传输方法尝试绕过的话,会被WAF直接识别并阻断。我们可以在[RFC7230]中查看到有关分块传输的定义规范4.1. Chunked Transfer Coding The chunked transfer coding wraps the payload body in order to transfer it as a series of chunks, each with its own size indicator, followed by an OPTIONAL trailer containing header fields. Chunked enables content streams of unknown size to be transferred as a sequence of length-delimited buffers, which enables the sender to retain connection persistence and the recipient to know when it has received the entire message. chunked-body = *chunk last-chunk trailer-part
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