rsa4py 0.0.2.0.dev1

python implementation of the rsa algorythem

Rsa4Py

rsa4py is a python library used to encript and decript string to lists of positive intagers

Table of Contents

[TOCM]

[TOC]

Key Generation

keys are divided into Public and Private keys. Public keys can be used to encript messages whereas Private can encript and decript.

Private Key

to generate a private Key can must use 2 larg prime numbers. the library dose not test if its a prime number so make sure they are. you can alsow specify a modular value n. n will be generated if not passed or incorrect. to generate just use, where p and q are the prime numbers:

key = rsa4py.PrivateKey(p, q)

if you want to generate with n

key = rsa4.py.PrivateKey(p, q, n)

Public Key

to generate a public key you can eather pass the modular value n and the encription key e. or you can generate it from a private key.

to generate from public key k. use

publicKey = k.getPublic()

to get from n and e use:

publicKey = rsa4py.PublicKey(n, e)

usage

encription

encription can be done with both the Public and Private Keys. both methods work the same way. For a given key k and a text t the encripton works as followes.

msg = k.encript(t)

out will be a list of values of the valus of the encripted text.

decription

for decription you need to use the Private key. this works as follows. for a given private key k, an encripted text out, t will be the decripted text

t = k.decript(msg)

message

during endcription and decription we used the variable msg witch is a CritptoMessage class witch is a subclass of a list. it contains the entripted message as itself, an intager signature witch is the authentication value of the message. ###saving messages### to save a message use the following function where filename is the name of the file to save to (no file extension) and msg is the message to save

msg.save(filename)

you can also use somthing like pickle directly by for example:

pickle.dump(msg, open(f"{filename}.msg.p, "wb))

###loading messages### loding is done using the loadMsg function. again filename is the name of the file to load from.

msg = rsa4py.loadMsg(filename)

or using somthing like pickle directly:

msg = pickle.load(open(f"{filename}.msg.p", "rb"))

authentication

the library suports authentication of messages. this is done usind the senders private and public keys.

###signing### to sign a messsage you have to use your own PrivateKey p and a message msg

msg.sign(p)

###authenticating### when trying to figure out if a messages signature is correct you have to use the signatureCorrect method. this is done using the PublicKey k of the sender (aka p.getPublic())

out  = msg.signatureCorrect(k)

out will be a boolean value witch is true if the authentication was correct.

filed keys

saving

you can alsow save a key k to a file and load them later using:

k.save(file)

where file is the string containing the filename and path (no extension). the extension will be ".rsa.p".

loading

to load a key again you have to run the function:

key = rsa4py.loadKey(file)

where file is the name of the file containining the key without extension.

instalation

to install rsa4py via pi just use

pip install rsa4py