Using a bookmarklet to store passwords is appealingly simple. Alas, after doing some digging, I couldn’t find any viable options.<\/p>\n
The first concern I came across is that it is important to use a hash algorithm that’s <\/a>slow<\/a><\/em> (e.g. bcrypt<\/a> or scrypt<\/a>).<\/em> Otherwise it’s too easy to brute-force the master password based on a site password. Suppose a site you visit stores your password in plaintext and gets hacked. That breach then compromises your master password, even though only your site-specific password was revealed.<\/p>\n I couldn’t find a JavaScript implementation of scrypt, but I found a JavaScript bcrypt implementation<\/a>. Better yet, I found a derivative that tidies up the first one, removing dependencies on e.g. ClipperZ<\/a>, and wraps it in a simple bookmarklet<\/a>. SuperGenPass<\/a> provides a much more user-friendly bookmarklet, so I started gearing up to replace it’s MD5 hashing with bcrypt.<\/p>\n But, alas, SuperGenPass (and any other simple bookmarklet) is not secure<\/a> in the face of a malicious website that contains JavaScript designed to sniff entry of the master password into the bookmarklet. PwdHash<\/a> is a browser extension based approach from the Stanford Security Lab designed to combat the weaknesses of the bookmarklet based approach. Their paper, Stronger Password Authentication Using Browser Extensions<\/a>, is interesting reading and explains a variety of ways to compromise a bookmarklet based approach. PwdHash has already spawned a number of ports to other browsers and mobile devices, but alas they’re all based on prototype code that uses the undesirably fast HMAC-MD5 as the hashing algorithm (even though the paper points out PwdHash is a good candidate for a better hashing algorithm).<\/p>\n I was not able to find any PwdHash derivative that used bcrypt. I did find a simple command-line tool based on scrypt<\/a>, but that’s not great if you don’t have easy access to your own computer.<\/p>\n Solutions like PassPack<\/a> offer the potential to solve these problems (extension rather than bookmarklet, use of strong encryption rather than weak hashing), but have an Achilles heel of their own: the service provider has the power to decrypt all your passwords<\/a>. For now I’ll stick with my moinmoin-client-crypt<\/a> approach.<\/p>\n UPDATE 2012-05-19<\/strong>: PassPack does not store<\/a> your packing key on their servers afterall. (LastPass does not either<\/a>, nor does Clipperz<\/a>.) But you still must trust them, as they are in a position to insert backdoors into either the browser add-ons or web-based access they provide. This is less of an issue with ClipperZ, since you can run the Community Edition<\/a> on your own hardware. Some brief comparisons here<\/a> and here<\/a>. Also there is some interesting discussion in the comments of the previously linked PassPack critique<\/a>. Gabriel Weinberg has LastPass amongst his list of services used at DuckDuckGo<\/a>. LastPass did possibly have a data breach, but they handled it well<\/a>. Some more details on PassPack’s packing keys and master keys<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" Using a bookmarklet to store passwords is appealingly simple. Alas, after doing some digging, I couldn’t find any viable options. The first concern I came across is that it is important to use a hash algorithm that’s slow (e.g. bcrypt or scrypt). Otherwise it’s too easy to brute-force the master password based on a site […]<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[52],"tags":[6],"_links":{"self":[{"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/posts\/53"}],"collection":[{"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/comments?post=53"}],"version-history":[{"count":6,"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/posts\/53\/revisions"}],"predecessor-version":[{"id":184,"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/posts\/53\/revisions\/184"}],"wp:attachment":[{"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/media?parent=53"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/categories?post=53"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lorrin.org\/blog\/wp-json\/wp\/v2\/tags?post=53"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}