A Method for Identifying and Deciphering Fragile Hash Functions for Smart Device Firmware

Abstract

The embodiment of the invention provides a method for identifying and cracking a fragile hash function for firmware of intelligent equipment, which mainly comprises the following steps of: preprocessing the firmware to obtain a binary file to be analyzed; extracting common characteristics of the fragile hash function which is not influenced by the architecture and the compiling optimization options or is influenced by the architecture and the compiling optimization options to be smaller than a preset threshold value; carrying out numerical processing on the features, training and testing the feature data, constructing a reliable neural network model based on logistic regression, and carrying out firmware fragile hash function identification and positioning based on a structured matching method; structural division and extraction are conducted on codes of the fragile hash function, machine codes or assembly codes are converted into VEX IR statements, a Z3 SMT solving expression executedbased on symbols is constructed, solving constraint conditions are added, a collision value is cracked reversely, and whether the collision value is correct or not is verified. The method has the advantages of being low in false alarm rate, accurate in positioning and high in cracking rate for the fragile hash function of the firmware.

Description

technical field [0001] The embodiment of the present invention relates to the field of function association of intelligent embedded device firmware and binary program function vulnerability mining, and specifically relates to a method for identifying and cracking a fragile hash function of intelligent device firmware. Background technique [0002] In recent years, due to the frequent occurrence of smart device firmware vulnerability attacks, the research and analysis of firmware security has become one of the research priorities and hotspots in the field of information security. Since the operation of embedded devices is practical and has limited computing power, in order to optimize the performance of the devices, some extremely fragile hash functions are used or the standard hash functions are simplified, resulting in security flaws in smart devices, resulting in The security of smart device systems and even the entire network security space is facing a huge threat. There...

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Problems solved by technology

[0007] The embodiment of the present invention provides a method for identifying and cracking the fragile hash function of the firmware of the smart device, which is used to solve the existing lack of a method that is simple to implement and has a low false positive rate for the identification of the fragile hash function of the firmware of the smart device, Defects of accurate positioning and fast cracking automated analysis methods

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