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POEquivalent to Unix cksum in Windows
 

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    <p>I download a file and his checksum (generated by cksum Unix command).</p> <p>So, I want, in my C# app test if the Checksum is in adequation with the app I downloaded.</p> <p>I checked at the Unix man page of chsum:</p> <blockquote> <pre><code> The cksum command calculates and prints to standard output a checksum for each named file, the number of octets in the file and the filename. cksum uses a portable algorithm based on a 32-bit Cyclic Redundancy Check. This algorithm finds a broader spectrum of errors than the 16-bit algorithms used by sum (see sum(1)). The CRC is the sum of the following expressions, where x is each byte of the file. x^32 + x^26 + x^23 +x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x^1 + x^0 The results of the calculation are truncated to a 32-bit value. The number of bytes in the file is also printed. </code></pre> </blockquote> <p>So i wrote a simple program that does the sum :</p> <pre><code>byte[] arr = File.ReadAllBytes(@"MyApp").ToArray(); int cksum = 0; foreach (byte x in arr) { cksum += (x ^ 32 + x ^ 26 + x ^ 23 + x ^ 22 + x ^ 16 + x ^ 12 + x ^ 11 + x ^ 10 + x ^ 8 + x ^ 7 + x ^ 5 + x ^ 4 + x ^ 2 + x ^ 1 + x ^ 0); } </code></pre> <p>But checksums aren't the same, how can I fix this?</p> <p>Thanks</p> <hr> <h2>EDIT</h2> <p>1) The modified algorithm is:</p> <pre><code>uint cksum = 0; foreach (byte b in arr) { var x = (uint)b; cksum += (IntPow(x, 32) + IntPow(x, 26) + IntPow(x, 23) + IntPow(x, 22) + IntPow(x, 16) + IntPow(x, 12) + IntPow(x, 11) + IntPow(x, 10) + IntPow(x, 8) + IntPow(x, 7) + IntPow(x, 5) + IntPow(x, 4) + IntPow(x, 2) + IntPow(x, 1) + IntPow(x, 0)); } </code></pre> <p>2) I used the <code>class Crc32 : HashAlgorithm</code></p> <p>Given an Unix file where the Crc32 is : 2774111254</p> <ul> <li>1) Gives me : 4243613712</li> <li>2) Gives me : 3143134679 (with a seed of 0)</li> </ul> <p>What I'm doing wrong !?</p>
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    1. COFor a C# implementation of crc32 check http://stackoverflow.com/q/4656659/11343
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