Yes, MD5 is somewhat less CPU-intensive. On my Intel x86 (Core2 Quad Q6600, 2.4 GHz, using one core), I get this in 32-bit mode: MD5 411 SHA-1 218 SHA-256 118 SHA-512 46 and this in 64-bit mode: MD5 407 SHA-1 312 SHA-256 148 SHA-512 189 Figures are in megabytes per second, for a “long” message … Read more
What you describe is called a collision. Collisions necessarily exist, since SHA-1 accepts many more distinct messages as input that it can produce distinct outputs (SHA-1 may eat any string of bits up to 2^64 bits, but outputs only 160 bits; thus, at least one output value must pop up several times). This observation is … Read more
There’s no such direct mapping in git as the name of the file is part of the tree object that contains the file, not of the blob object that is the file’s contents. It’s not a usual operation to want to retrieve a file name from a SHA1 hash so perhaps you could expand on … Read more
using (FileStream fs = new FileStream(@”C:\file\location”, FileMode.Open)) using (BufferedStream bs = new BufferedStream(fs)) { using (SHA1Managed sha1 = new SHA1Managed()) { byte[] hash = sha1.ComputeHash(bs); StringBuilder formatted = new StringBuilder(2 * hash.Length); foreach (byte b in hash) { formatted.AppendFormat(“{0:X2}”, b); } } } formatted contains the string representation of the SHA-1 hash. Also, by using … Read more
Here’s a module for calculating SHA1 hashes that is usable for Excel formulas eg. ‘=SHA1HASH(“test”)’. To use it, make a new module called ‘module_sha1’ and copy and paste it all in. This is based on some VBA code from http://vb.wikia.com/wiki/SHA-1.bas, with changes to support passing it a string, and executable from formulas in Excel cells. … Read more
Picking atoms on 10 Moons An SHA-1 hash is a 40 hex character string… that’s 4 bits per character times 40… 160 bits. Now we know 10 bits is approximately 1000 (1024 to be exact) meaning that there are 1 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 … Read more
I would use VARCHAR for variable length data, but not with fixed length data. Because a SHA-1 value is always 160 bit long, the VARCHAR would just waste an additional byte for the length of the fixed-length field. And I also wouldn’t store the value the SHA1 is returning. Because it uses just 4 bit … Read more
DEBUG: Click on the Gradle tab on the right hand side of the view. Go to the ROOT folder -> Tasks -> android -> signingReport Double click, this will build with the signingReport and post in your bottom view your SHA1. RELEASE: In android studio. Build -> Generate Signed APK… and click Next Copy your … Read more
You don’t need andorid for this. You can just do it in simple java. Have you tried a simple java example and see if this returns the right sha1. import java.io.UnsupportedEncodingException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class AeSimpleSHA1 { private static String convertToHex(byte[] data) { StringBuilder buf = new StringBuilder(); for (byte b : data) … Read more
Git prefixes the object with “blob “, followed by the length (as a human-readable integer), followed by a NUL character $ echo -e ‘blob 14\0Hello, World!’ | shasum 8ab686eafeb1f44702738c8b0f24f2567c36da6d Source: http://alblue.bandlem.com/2011/08/git-tip-of-week-objects.html