crc32

I want my Greasemonkey script to run ONLY when the static page it's accessing has the exact same content as before... Now I have the ability to set a variable containing a hash of this page. I'm looking for a way to hash the page on the fly, so that I can compare my hash to the generated hash... Any ideas on how to accomplish this, on the fly, hashing? Brock Adams From your question: I want my Greasemonkey script to run ONLY when the static page it's accessing has the exact same content as before... What you really want is for your script to detect page changes. A hash is not normally the best

I found a code to reverse CRC32 but I don't know how it works, because im not that good in programming, I just started. I just want to compare 2 files, the old and the new one, then in the new fix the CRC32 adding 4 bytes at the end of the file, so the 2 files will have the same CRC32. Here is the code, is in C#: public class Crc32 { public const uint poly = 0xedb88320; public const uint startxor = 0xffffffff; static uint[] table = null; static uint[] revtable = null; public void FixChecksum(byte[] bytes, int length, int fixpos, uint wantcrc) { if (fixpos + 4 > length) return; uint crc =

Closed. This question is off-topic. It is not currently accepting answers. Learn more . Want to improve this question? Update the question so it's on-topic for Stack Overflow. I am trying to implement a CRC32 algorithm in C that does not use a look up table (I need to use it in a boot loader that doesn't have enough memory available to have one). Is there an available solution to this that has a public license? A quick search harvested this webpage . I wasn't able to find the license for these code snippets. The following should do the job: // ----------------------------- crc32b -------------

I am trying to generate CRC with STM32L4 hardware modul. I would like to validate fatfs files so basically I have byte arrays. I am using this CRC generator . Unfortunately I cannot figure out how to set STM32L4 to generate the same result. I need CRC32 and I have configuration: hcrc.Instance = CRC; /* The default polynomial is not used. It is required to defined it in CrcHandle.Init.GeneratingPolynomial*/ hcrc.Init.DefaultPolynomialUse = DEFAULT_POLYNOMIAL_DISABLE; /* Set the value of the polynomial */ hcrc.Init.GeneratingPolynomial = 0x4C11DB7; //hcrc.Init.GeneratingPolynomial = 0xFB3EE248;

I'm trying to calculate the Frame Check Sequence (FCS) of an Ethernet packet byte by byte. The polynomial is 0x104C11DB7 . I did follow the XOR-SHIFT algorithm seen here http://en.wikipedia.org/wiki/Cyclic_redundancy_check or here http://www.woodmann.com/fravia/crctut1.htm Assume the information that is supposed have a CRC is only one byte. Let's say it is 0x03. step: pad with 32 bits to the right 0x0300000000 align the polynomial and the data at the left hand side with their first bit that is not zero and xor them 0x300000000 xor 0x209823B6E = 0x109823b6e take remainder align and xor again