PJ 0910064001 Refactored Code | 2 years ago | |
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generator | 2 years ago | |
LICENSE | 3 years ago | |
README.md | 2 years ago | |
optimus.go | 2 years ago | |
optimus_test.go | 2 years ago |
There are many times when you want to generate obfuscated ids. This package utilizes Knuth’s Hashing Algorithm to transform your internal ids into another number to hide it from the general public.
An example may be your database table. You may have a primary key that points to a particular customer. For security reasons you don’t want to expose that id to the outside world. That is exactly where this package becomes handy.
Optimus encodes your internal id to a number that is safe to expose. Finally it can decode that number back so you know which internal id it refers to.
Full Unit Tests are provided. The package is Google App Engine compatible.
go get -u github.com/pjebs/optimus-go
2147483647
(MAXID)(PRIME * INVERSE) & MAXID == 1
2147483647
(MAXID).You can use the built-in GenerateSeed()
function to generate all 3 required parameters if you want. This is not recommended though because it is reliant on the prime numbers listed on the website: http://primes.utm.edu/lists/small/millions/. This adds a point of insecurity.
If you do use the GenerateSeed()
function, make sure that you verify:
package hello
import (
"fmt"
"github.com/pjebs/optimus-go"
)
o := optimus.New(1580030173, 59260789, 1163945558) //Prime Number: 1580030173, Mod Inverse: 59260789, Pure Random Number: 1163945558
new_id := o.Encode(15) //internal id of 15 being transformed to 1103647397
orig_id := o.Decode(1103647397) //Returns 15 back
Please note that in order for Optimus to transform the id back to the original, all 3 numbers of the constructor must be consistent. You will need to store it somewhere after generation and usage.
type Optimus struct {
prime uint64
modInverse uint64
random uint64
}
func New(prime uint64, modInverse uint64, random uint64) Optimus
Returns an Optimus struct which can be used to encode and decode integers. Usually used for obfuscating internal ids such as database table rows. Panics if prime is not valid.
func NewCalculated(prime uint64, random uint64) Optimus
Returns an Optimus struct which can be used to encode and decode integers. Usually used for obfuscating internal ids such as database table rows. This method calculates the modInverse computationally. Panics if prime is not valid.
func (this Optimus) Encode(n uint64) uint64
Encodes n using Knuth’s Hashing Algorithm. Ensure that you store the prime, modInverse and random number associated with the Optimus struct so that it can be decoded correctly.
func (this Optimus) Decode(n uint64) uint64
Decodes a number that had been hashed already using Knuth’s Hashing Algorithm. It will only decode the number correctly if the prime, modInverse and random number associated with the Optimus struct is consistent with when the number was originally hashed.
func (this Optimus) Prime() uint64
Returns the Associated Prime Number. DO NOT DIVULGE THIS NUMBER!
func (this Optimus) ModInverse() uint64
Returns the Associated ModInverse Number. DO NOT DIVULGE THIS NUMBER!
func (this Optimus) Random() uint64
Returns the Associated Random Number. DO NOT DIVULGE THIS NUMBER!
func ModInverse(n int64) uint64
Calculates the Modular Inverse of a given Prime number such that (PRIME * MODULAR_INVERSE) & (MAX_INT_VALUE) = 1
Panics if n is not a valid prime number.
See: http://en.wikipedia.org/wiki/Modular_multiplicative_inverse
func generator.GenerateSeed(req *http.Request) (*Optimus, uint8, error)
Generates a valid Optimus struct using a randomly selected prime number from this site: http://primes.utm.edu/lists/small/millions/
The first 50 million prime numbers are distributed evenly in 50 files.
This Function is Time, Memory and CPU intensive. Run it once to generate the required seeds.
WARNING: Potentially Insecure. Double check that the prime number returned is actually prime number using an independent source.
The largest Prime has 9 digits. The smallest has 1 digit.
The second return value is the website zip file identifier that was used to obtain the prime number
NB: Parameter req
should be nil if not using Google App Engine.
There is the hashids package which is very popular. Out of the box, it produces obfuscated ids that can contain any number of characters.
However:
This package is based on the PHP library by jenssegers.
If you found this package useful, please Star it on github. Feel free to fork and/or provide pull requests. Any bug reports will be warmly received.