How get int from base64'd number bytes representation in Go

#go #base64 #cryptography #rsa

To make sure we won't overflow, we need math/big from Go

inputString := "Ag==" // base64'd byte representation of number 2

// first base64 -> bytes 
decodedBytes, _ := b64.StdEncoding.DecodeString(inputString)

// bytes -> big.Int
bigInt := new(big.Int)
bigInt.SetBytes(decodedBytes)

resultInt64 := bigInt.Int64() // == int64(2)
resultInt := int(resultInt64) // == int(2)