System.Security.Cryptography.MD5.Create() is actually creating a MD5CryptoServiceProvider. That is why you see the same results. Looking at the definition MD5 is the base class and it’s abstract. I’m guessing they added the public create function for ease of use. public sealed class MD5CryptoServiceProvider : MD5 { } public abstract class MD5 : HashAlgorithm { } Take … Read more
git calculates hashes like this: sha1(“blob ” + filesize + “\0” + data) Reference
Here’s a quote from Effective Java 2nd Edition, Item 9: “Always override hashCode when you override equals“: While the recipe in this item yields reasonably good hash functions, it does not yield state-of-the-art hash functions, nor do Java platform libraries provide such hash functions as of release 1.6. Writing such hash functions is a research … Read more
One hex character can only represent 16 different values, i.e. 4 bits. (16 = 24) 40 × 4 = 160. And no, you need much more than 5 characters in base-36. There are totally 2160 different SHA-1 hashes. 2160 = 1640, so this is another reason why we need 40 hex digits. But 2160 = … Read more
>> require ‘ostruct’ => [] >> foo = {‘bar’=>’baz’} => {“bar”=>”baz”} >> foo_obj = OpenStruct.new foo => #<OpenStruct bar=”baz”> >> foo_obj.bar => “baz” >>
Don’t use a simple hash, or even a salted hash. Use some sort of key-strengthening technique like bcrypt (with a .NET implementation here) or PBKDF2 (with a built-in implementation). Here’s an example using PBKDF2. To generate a key from your password… string password = GetPasswordFromUserInput(); // specify that we want to randomly generate a 20-byte … Read more
On some sites you can separate the “important stuff” from the “really, really important stuff”. Let’s say that the “important stuff” on your site allows users to view policies, active members and incoming group messages. The “really, really important stuff” allows you to change policies, reset passwords and add new users. So what you can … Read more
So, when not wanting to use boost, Michael Blurr’s comment led to the following hash function implementation: std::size_t operator()(std::vector<uint32_t> const& vec) const { std::size_t seed = vec.size(); for(auto& i : vec) { seed ^= i + 0x9e3779b9 + (seed << 6) + (seed >> 2); } return seed; } Seems to work. Edit: see’s answer … Read more
Here is a simple Map implementation that will work with any type of key, including object references, and it will not mutate the key in any way: function Map() { var keys = [], values = []; return { put: function (key, value) { var index = keys.indexOf(key); if(index == -1) { keys.push(key); values.push(value); } … Read more
if (history.pushState) { // supported. } Quickest test is to run this in the browser console to see if it’s supported: if (history.pushState) { alert(‘supported’); } Also notice that in FF typeof(history.pushState) returns “function”, while in IE it returns “undefined”