Patent ID: 7844683
Filing Date: 2010-11-30
Classification: H04L

Abstract:
1. A computer-implemented method for comparing an unknown string to a predefined string, the method comprising: storing, on a network device, a database containing a plurality of predefined strings in ASCII binary representation, wherein the predefined strings stored within the database represent known headers for a network communication protocol; receiving, with the network device, a network message having characters in ASCII binary representation, wherein a case of the characters of the received network message is unknown by the network device; in response to receiving the network message, selecting one of the plurality of predefined strings stored within the database of the network device; identifying a portion of the network message as an unknown string for comparison with the selected predefined string, wherein the unknown string and the selected predefined string have an equal number of characters; dividing the unknown string and the selected predefined string into segments, wherein the segments of the unknown string and the segments of the selected predefined string have an equal number of the characters; performing a bitwise exclusive OR operation between the ASCII binary representation of each of the segments of the unknown string and the ASCII binary representation of each of the segments of the selected predefined string; performing a bitwise operation between a predefined flag and each result of the exclusive OR operations, wherein the predefined flag has an equal number of characters as the result of the exclusive OR operation; comparing the predefined flag and each result of the bitwise operations to produce an indication for a case-insensitive string match, wherein the indication for the case-insensitive string match indicates whether all the characters of the segments of the unknown string within the network message match all the corresponding characters of the segments of the selected predefined string so as to match one of the known headers of the network communication protocol; processing the network message based on the indication of the case-insensitive string match; and outputting a response from the network device based on the processed network message.