11–20 of 126 posts
For those who don't want to read the source code, BozoCrack has a simple algorithm. It googles the MD5 hash and hopes the first result page contains the plaintext password. It usually does.
I don't think it's demonstrating anything other than: 1) many developers don't use salts / HMAC 2) MD5 is popular 3) hashed passwords end up on Google From these 3 points I don't think it follows that MD5 is horrible. Any hashing function would have the same issues, simply because a hashing function is a mathematical function, so for any X from the domain of definition, H(X) will always have the same value, on every…
I don't think it's demonstrating anything other than: 1) many developers don't use salts / HMAC 2) MD5 is popular 3) hashed passwords end up on Google From these 3 points I don't think it follows that MD5 is horrible. Any hashing function would have the same issues, simply because a hashing function is a mathematical function, so for any X from the domain of definition, H(X) will always have the same value, on every…
I don't think it's demonstrating anything other than: 1) many developers don't use salts / HMAC 2) MD5 is popular 3) hashed passwords end up on Google From these 3 points I don't think it follows that MD5 is horrible. Any hashing function would have the same issues, simply because a hashing function is a mathematical function, so for any X from the domain of definition, H(X) will always have the same value, on every…
Think of (3) as saying without salting, with Google and the internet, the precomputed tables that are used for brute-force attacks are already out there and can be queried with a simple Ruby program.
Note to self: poison search results for md5 hashes of my passwords.
Edit: I'm trying to illustrate the general principle, that you shouldn't take any action thats visible outside your secure perimeter, that depends on knowledge of your password.
What you define as 'outside the perimeter' depends. In the case of your corporate systems, its probably everything outside the corporate network. In the case of your gmail password, its everything outside of [your computer, the SSL connection to google's auth servers, and those servers].
You shouldn't ever leak any information outside that perimeter, that reveals knowledge of your password.
Its generally pretty hard to steal the password hash; if you start revealing what your password hash is to someone doing passive analysis, you compromise a lot.
If its worth thinking about poisoning hashes to protect, then don't try and poison the hashes!
Earlier quoted context omitted.
Think of (3) as saying without salting, with Google and the internet, the precomputed tables that are used for brute-force attacks are already out there and can be queried with a simple Ruby program.
Why ruby in particular?
For those who don't want to read the source code, BozoCrack has a simple algorithm. It googles the MD5 hash and hopes the first result page contains the plaintext password. It usually does.
"It usually does" isn't quite accurate here. Common or weak plaintexts might work, but for the vast majority of input you're SOL. Sure "nicetry" comes back, but "nicetry99" produces 0 results and for every "nicetry" there are an infinite number of "nicetry"+i hashes.
Note to self: poison search results for md5 hashes of my passwords.
Because that way, anyone sniffing or monitoring your traffic doesn't even need to crack the systems to steal the hash, and so you'll be saving everyone some time? Edit: I'm trying to illustrate the general principle, that you shouldn't take any action thats visible outside your secure perimeter, that depends on knowledge of your password. What you define as 'outside the perimeter' depends. In the case of your corpora…
I don't think it's demonstrating anything other than: 1) many developers don't use salts / HMAC 2) MD5 is popular 3) hashed passwords end up on Google From these 3 points I don't think it follows that MD5 is horrible. Any hashing function would have the same issues, simply because a hashing function is a mathematical function, so for any X from the domain of definition, H(X) will always have the same value, on every…
Perhaps I should have written it as "unsalted MD5" instead of "plain MD5" to avoid confusion. Unsalted MD5, in my opinion, is horrible. MD5 plays it's part in the mess: it's quick to calculate, which means that anybody can churn out huge lookup databases. Missing salts make those databases universally usable.
"Huge" being the key word here.
Try searching for the md5sums of arbitrary 8-character alphanumeric passwords. You won't find many results. 62^8 is a big number.