Simon Willison’s Weblog

Redis weekly update #1—Hashes and... many more! Hashes were the big missing data type in Redis—support is only partial at the moment (no ability to list all keys in a hash or delete a specific key) but at the rate Redis is developed I expect that to be fixed within a week or two.

# 13th March 2010, 12:06 am / redis, hashes, keyvaluestores, nosql

Researchers Show How to Forge Site Certificates. Use an MD5 collision to create two certificates with the same hash, one for a domain you own and another for amazon.com. Get Equifax CA to sign your domain’s certificate using the outdated “MD5 with RSA” signing method. Copy that signature on to your home-made amazon.com certificate to create a fake certificate for Amazon that will be accepted by any browser.

# 30th December 2008, 3:27 pm / md5, ssl, collisions, hashes, equifaxca, security, edfelten

Django snippets: Sign a string using SHA1, then shrink it using url-safe base65. I needed a way to create tamper-proof URLs and cookies by signing them, but didn’t want the overhead of a full 40 character SHA1 hash. After some experimentation, it turns out you can knock a 40 char hash down to 27 characters by encoding it using a custom base65 encoding which only uses URL-safe characters.

# 27th August 2008, 10:18 pm / django-snippets, django, python, hashes, sha1, base65, cryptography, security, cookies, signedcookies, urls