175 the logs matches the patterns determined by the regular |
175 the logs matches the patterns determined by the regular |
176 expressions. Such decisions need to be done as fast as possible, |
176 expressions. Such decisions need to be done as fast as possible, |
177 otherwise the scanning programs would not be useful as a hardening |
177 otherwise the scanning programs would not be useful as a hardening |
178 technique for servers. The quest for speed with these decisions is |
178 technique for servers. The quest for speed with these decisions is |
179 presently a rather big challenge for the amount of traffic typical |
179 presently a rather big challenge for the amount of traffic typical |
180 serves have to cope with and the large number of patterns that might |
180 servers have to cope with and the large number of patterns that might |
181 be of interest. The problem is that when thousands of regular |
181 be of interest. The problem is that when thousands of regular |
182 expressions are involved, the process of detecting whether a string |
182 expressions are involved, the process of detecting whether a string |
183 matches a regular expression can be excruciating slow. This might not |
183 matches a regular expression can be excruciating slow. This might not |
184 happen in most instances, but in some small number of |
184 happen in most instances, but in some small number of |
185 instances. However in these small number of instances the algorithm |
185 instances. However in these small number of instances the algorithm |