Private key calculations

[RentGPU]

Say i don't want to generate a random private key , but i want to convert a number to be my private key , so i tried to do the steps but it seems the sha256 online calculators are not working in the same way, the steps 1-add0x80 byte 2-sha256(step1) 3-sha255(step2) 4-first 4bytes 5-add first 4 bytes to step1(checksum).....the problem here is i use the sha256 online calculators to convert the first step but the result is not anything like it should be , if you know any online calculators i can use plz tell me , thx

[achow101]

Are you hashing the number as a string? Is it in decimal or hex?

You must be hashing your number as bytes. Otherwise it will not be correct as you would be hashing a string.

[slavikus]

You can also play around and verify your results with http://gobittest.appspot.com/Address

[Coding Enthusiast]

Here you go:
Step2 SHA256: http://www.fileformat.info/tool/hash.htm?hex=800C28FCA386C7A227600B2FE50B7CAE11EC86D3BF1FBE471BE89827E19D72AA1D
Step3 SHA256: http://www.fileformat.info/tool/hash.htm?hex=8147786c4d15106333bf278d71dadaf1079ef2d2440a4dde37d747ded5403592

Those online tools like this one http://passwordsgenerator.net/sha256-hash-generator/ you use are treating your Hex as a string.

P.S. Example was taken from wiki, and I hate the person who added _SAMPLE_PRIVATE_KEY_DO_NOT_IMPORT_ to the copied result  Be careful to remove it when you are trying to test and copy things or it will cause you a lot of headache since you may not know why the result is wrong with first look.

[pebwindkraft]

besides the ones already mentioned, I used these links to play with keys and addresses:

https://www.bitaddress.org/
http://lenschulwitz.com/base58
http://ciyam.org/rawtx_helper.html