md5

MD5 and SHA-1 hashes have weaknesses against collision attacks. SHA256 does not but it outputs 256 bits. Can I safely take the first or last 128 bits and use that as the hash? I know it will be weaker (because it has less bits) but otherwise will it work? Basically I want to use this to uniquely identify files in a file system that might one day contain a trillion files. I'm aware of the birthday problem and a 128 bit hash should yield about a 1 in a trillion chance on a trillion files that there would be two different files with the same hash. I can live with those odds. What I can't live

I'm having a hard time with this, conceptually. Basically, I need to accept some arbitrary unique string, and be able to convert that to a normalized float value. What the output float value is doesn't really matter, so long as the same string input always results in the same normalized float output. So this is a hashing algorithm right? I'm familiar with SHA1 or MD5, and this seems similar to password hashing where the result is the same for the correct password. But those methods output strings of characters, I believe. And what I'm not getting is how I would turn the result of a SHA1 or MD5

I am working with JavaScript to generate File HASH VALUE for unique file values. Kindly check the below code for the Hash Generation Mechanism Which works good. <script type="text/javascript"> // Reference: https://code.google.com/p/crypto-js/#MD5 function handleFileSelect(evt) { var files = evt.target.files; // FileList object // Loop through the FileList and render image files as thumbnails. for (var i = 0, f; f = files[i]; i++) { var reader = new FileReader(); // Closure to capture the file information. reader.onload = (function(theFile) { return function(e) { var span = document

I'm trying to write some code to work with an htdigest password file. The documentation I can find seems to claim that the format of that file is: user:realm:MD5(user:realm:pass) If that is the case, then why doesn't this work for me? I created a file with the command line htdigest thus: htdigest -c test b a When prompted for a password I entered 'c'. This creates a file with the contents: a:b:02cc8f08398a4f3113b554e8105ebe4c However if I try to derive this hash I can't, echo a:b:c | md5 gives me "49d6ea7ca1facf323ca1928995420354". Is there something obvious that I'm missing here? Thanks echo

I am trying to create an android MD5 hash string to equal the C# code bellow: private string CalculateHMACMd5(string message, string key) { System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding(); byte[] keyByte = encoding.GetBytes(key); HMACMD5 hmacmd5 = new HMACMD5(keyByte); byte[] messageBytes = encoding.GetBytes(message); byte[] hashmessage = hmacmd5.ComputeHash(messageBytes); string HMACMd5Value = ByteToString(hashmessage); return HMACMd5Value; } private static string ByteToString(byte[] buff) { string sbinary = ""; for (int i = 0; i < buff.Length; i++) { sbinary += buff[i]

Need MD5 hash for an in memory System.Drawing.Image Here is a basic snippet. See also @JaredReisinger 's comment for some questions. using System.Security.Cryptography; using System.Text; using System.Drawing.Imaging; // ... // get the bytes from the image byte[] bytes = null; using( MemoryStream ms = new MemoryStream() ) { image.Save(ms,ImageFormat.Gif); // gif for example bytes = ms.ToArray(); } // hash the bytes MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider(); byte[] hash = md5.ComputeHash(bytes); // make a hex string of the hash for display or whatever StringBuilder sb = new

I am trying to input a text file that contains MD5 hashes and keywords (one per line) into a C# app. Is there a way to check if a string is an MD5 hash? I looked on MSDN and couldn't find anything in the MD5 class. THX-1138 Use Regex like this: public static bool IsMD5(string input) { if (String.IsNullOrEmpty(input)) { return false; } return Regex.IsMatch(input, "^[0-9a-fA-F]{32}$", RegexOptions.Compiled); } Well, an MD5 hash is really just binary data - if you've got a string then it's presumably encoded in some fashion, e.g. base64 or hex. You can test whether the string is correctly encoded

I am running some code that I have written in C which calls the md5 hashing functionality from a hashing library that someone else wrote (md5.c & md5.h). The odd behavior I have been seeing is: hashing working perfectly = I hash a string, and it comes out to the exact hash that I have verified it to be with multiple other sources. Hashing functionality works perfectly when compiling and running on my OSX machine and the hash that is computed is exactly as it should be. Same code, no changes is uploaded and compiled on the Linux based server and it computes a different (wrong) hash. Does anyone