title: SHA1 collision demo / example
body: <p>This question is similar to <a href="https://stackoverflow.com/questions/1224113/examples-of-hash-collisions">this</a>, but that one only references MD5 collision demos.</p>
  
  <p>Are there any actual SHA1 collision pairs of arbitrary messages known so far ?</p>
  
  <p>I'd like to use these to test how various software products (my own one and some third party) deal with it.</p>
  
  <p>Doing some Google searches only turned up the oh-so prominent MD5 / SHA0 collisions and some hints on an approach to creating SHA1 collisions but I could not get my hands on any examples.</p>