checksum

问题 I am developing an application in flex in which I need to calculate checksum of different files. I would like to know if there is a direct method in actionscript to calculate that or do I have to go for any external libraries? Thanks in advance :) 回答1: as3corelib maintained by Mike Chambers/Adobe, contains everything you probably need in its crypto section including: HMAC MD5 MD5Stream SHA1 SHA224 SHA256 WSSEUsernameTocken 回答2: how do you use this as3corelib to perform a md5 on a file i.e. "c

问题 A sample of the data is: de 55 7a ff 41 4e 3b .. .. .. .. .. .. .. .. .. .. . . the sum of the first six numbers (in hex) is 33b and the "checksum" number is 3b , as the last 2 characters of the sum. What's the name of this check sum? How can i make it in Objective C? Thank you 回答1: To get checksum of a hex string is really straight forward, most of the time, we are just overthinking it. If you have a NSMutableData and want to get checksum of it, please check my answer here. If you have a

问题 I am writing a little POSIX program and I need to compute the checksum of a TCP segment, I would like use an existing function in order to avoid to writing one myself. Something like (pseudocode) : char *data = .... u16_integer = computeChecksum(data); I searched on the web but I did not find a right answer, any suggestion ? 回答1: Here, it's taken more or less directly from the RFC: uint16_t ip_calc_csum(int len, uint16_t * ptr) { int sum = 0; unsigned short answer = 0; unsigned short *w = ptr

问题 I am communicating with a machine over serial. Part of the protocol communication spec states that the control sum is an "arithmetic sum of bytes from <'PS'> (included), <'data'> to <'CS'>" The packet messages are structured as follows: <'PS'><'data'><'CS'>, where: <'PS'> - Packet Size Length: 1 Value: 0x02 to 0x63 Max packet length is 99 bytes <'data'> - Data Length: 1...90 bytes Value: 0x00 - 0xFF The length of the data part depends on the command. <'CS'> - Check Sum Length - 1 byte Value:

问题 i am trying to integrate payTm payment gateway ( Production ) in my app. i generate all the required credentials for it but when i press pay button from app it get redirected to payTm page and OOPS Something went wrong screen... appears 来源： https://stackoverflow.com/questions/48782215/ios-paytm-something-went-wrong-it-may-be-due-to-any-of-these-reasons

问题 I just had to scour the internet for this code yet again so I figured I would put it here so I can find it a little faster the next time and hopefully you found it a little faster too :) 回答1: Check this. The code below can check digit in all GTIN's (EAN8, EAN13, EAN14, UPC/A, UPC/E) CREATE FUNCTION [dbo].[check_digit] ( @GTIN VARCHAR(14) ) RETURNS TINYINT AS BEGIN DECLARE @Index TINYINT, @Multiplier TINYINT, @Sum TINYINT, @checksum TINYINT, @result TINYINT, @GTIN_strip VARCHAR(13) SELECT

问题 I'm coding a MODBUS CRC16 calculator in C. What I have before is a python that do this, I wanted to convert it to C. I found some codes online but it's not giving me the correct answer. For my python code, I have this as my CRC16.py #!/usr/bin/env python def calc(data): crc_table=[0x0000,0xC0C1,0xC181,0x0140,0xC301,0x03C0,0x0280,0xC241,0xC601,0x06C0,0x0780,0xC741,0x0500,0xC5C1,0xC481,0x0440,0xCC01,0x0CC0,0x0D80,0xCD41,0x0F00,0xCFC1,0xCE81,0x0E40,0x0A00,0xCAC1,0xCB81,0x0B40,0xC901,0x09C0

问题 I'm coding a MODBUS CRC16 calculator in C. What I have before is a python that do this, I wanted to convert it to C. I found some codes online but it's not giving me the correct answer. For my python code, I have this as my CRC16.py #!/usr/bin/env python def calc(data): crc_table=[0x0000,0xC0C1,0xC181,0x0140,0xC301,0x03C0,0x0280,0xC241,0xC601,0x06C0,0x0780,0xC741,0x0500,0xC5C1,0xC481,0x0440,0xCC01,0x0CC0,0x0D80,0xCD41,0x0F00,0xCFC1,0xCE81,0x0E40,0x0A00,0xCAC1,0xCB81,0x0B40,0xC901,0x09C0

问题 can anybody share a link or sample code to implement checksum for string in javascript? Thanks a lot in advance 回答1: What do you want? You need to be more specific. There is a huge plethora of CRC16 algorithms, each one with its own polynomial and for a specific use. Some CRC16 algorithms are really good to create hashes ( for Redis, for example ) while others are better for wire communication. https://en.wikipedia.org/wiki/Cyclic_redundancy_check#Polynomial_representations_of_cyclic

问题 can anybody share a link or sample code to implement checksum for string in javascript? Thanks a lot in advance 回答1: What do you want? You need to be more specific. There is a huge plethora of CRC16 algorithms, each one with its own polynomial and for a specific use. Some CRC16 algorithms are really good to create hashes ( for Redis, for example ) while others are better for wire communication. https://en.wikipedia.org/wiki/Cyclic_redundancy_check#Polynomial_representations_of_cyclic