I want to implement AES algorithm,instead of 128 bit key encryption I wanted to do it for 256.But I’m stuck at point creating scheduling for 256 key generation. Can anyone help in this.
I agree with @poncho, you have to read FIPS 197 (https://nvlpubs.nist.gov/nistpubs/fips/nist.fips.197.pdf). You should look on paragraph 5.2 Key Expansion. This one have a pseudo code. Also you can look on implementation in Go's runtime (https://github.com/golang/go/blob/master/src/crypto/aes/block.go).