lista - Cifrado privado/público en Python con biblioteca estándar

lista de modulos de python

Question

¿Hay algún módulo que no haya podido encontrar mi búsqueda que permitiría escribir código como el siguiente? La razón para querer escribir código como este no es importante. Todo lo que busco es un código que tiene una API simple para generar claves de bytes públicas y privadas y para codificar y descodificar fácilmente datos con esas claves.

import module, os
method, bits, data = ''RSA'', 1024, os.urandom(1024)
public, private = module.generate_keys(method, bits)
assert isinstance(public, bytes) and isinstance(private, bytes)
assert module.decode(module.encode(data, private), public) == data
assert module.decode(module.encode(data, public), private) == data

La mayoría de lo que parece estar disponible requiere la descarga de un paquete y solo se ejecuta en Python 2.x. También es bastante común encontrar bibliotecas que funcionen con archivos PEM u otros tipos de certificados. Me gustaría evitar tener que lidiar con dichos archivos, generar claves públicas y privadas sobre la marcha y trabajar rápidamente con los datos en la memoria.

Answer 1

Aquí hay otro ejemplo.

import random
# RSA Algorithm
ops = raw_input(''Would you like a list of prime numbers to choose from (y/n)? '')
op = ops.upper()
if op == ''Y'':
print """/n 2 3 5 7 11 13 17 19 23 29
31 37 41 43 47 53 59 61 67 71
73 79 83 89 97 101 103 107 109 113
127 131 137 139 149 151 157 163 167 173
179 181 191 193 197 199 211 223 227 229
233 239 241 251 257 263 269 271 277 281
283 293 307 311 313 317 331 337 347 349
353 359 367 373 379 383 389 397 401 409
419 421 431 433 439 443 449 457 461 463
467 479 487 491 499 503 509 521 523 541
547 557 563 569 571 577 587 593 599 /n"""
rsa()
else:
print "/n"
rsa()
def rsa():
# Choose two prime numbers p and q
p = raw_input(''Choose a p: '')
p = int(p)
while isPrime(p) == False:
print "Please ensure p is prime"
p = raw_input(''Choose a p: '')
p = int(p)
q = raw_input(''Choose a q: '')
q = int(q)
while isPrime(q) == False or p==q:
print "Please ensure q is prime and NOT the same value as p"
q = raw_input(''Choose a q: '')
q = int(q)
# Compute n = pq
n = p * q
# Compute the phi of n
phi = (p-1) * (q-1)
# Choose an integer e such that e and phi(n) are coprime
e = random.randrange(1,phi)
# Use Euclid''s Algorithm to verify that e and phi(n) are comprime
g = euclid(e,phi)
while(g!=1):
e = random.randrange(1,phi)
g = euclid(e,phi)
# Use Extended Euclid''s Algorithm
d = extended_euclid(e,phi)
# Public and Private Key have been generated
public_key=(e,n)
private_key=(d,n)
print "Public Key [E,N]: ", public_key
print "Private Key [D,N]: ", private_key
# Enter plain text to be encrypted using the Public Key
sentence = raw_input(''Enter plain text: '')
letters = list(sentence)
cipher = []
num = ""
# Encrypt the plain text
for i in range(0,len(letters)):
print "Value of ", letters[i], " is ", character[letters[i]]
c = (character[letters[i]]**e)%n
cipher += [c]
num += str(c)
print "Cipher Text is: ", num
plain = []
sentence = ""
# Decrypt the cipher text
for j in range(0,len(cipher)):
p = (cipher[j]**d)%n
for key in character.keys():
if character[key]==p:
plain += [key]
sentence += key
break
print "Plain Text is: ", sentence
# Euclid''s Algorithm
def euclid(a, b):
if b==0:
return a
else:
return euclid(b, a % b)
# Euclid''s Extended Algorithm
def extended_euclid(e,phi):
d=0
x1=0
x2=1
y1=1
orig_phi = phi
tempPhi = phi
while (e>0):
temp1 = int(tempPhi/e)
temp2 = tempPhi - temp1 * e
tempPhi = e
e = temp2
x = x2- temp1* x1
y = d - temp1 * y1
x2 = x1
x1 = x
d = y1
y1 = y
if tempPhi == 1:
d += phi
break
return d
# Checks if n is a prime number
def isPrime(n):
for i in range(2,n):
if n%i == 0:
return False
return True
character = {"A":1,"B":2,"C":3,"D":4,"E":5,"F":6,"G":7,"H":8,"I":9,"J":10,
"K":11,"L":12,"M":13,"N":14,"O":15,"P":16,"Q":17,"R":18,"S":19,
"T":20,"U":21,"V":22,"W":23,"X":24,"Y":25,"Z":26,"a":27,"b":28,
"c":29,"d":30,"e":31,"f":32,"g":33,"h":34,"i":35,"j":36,"k":37,
"l":38,"m":39,"n":40,"o":41,"p":42,"q":43,"r":44,"s":45,"t":46,
"u":47,"v":48,"w":49,"x":50,"y":51,"z":52, " ":53, ".":54, ",":55,
"?":56,"/":57,"!":58,"(":59,")":60,"$":61,":":62,";":63,"''":64,"@":65,
"#":66,"%":67,"^":68,"&":69,"*":70,"+":71,"-":72,"_":73,"=":74}

Answer 2

El cifrado de clave pública no está en la biblioteca estándar. Aunque hay algunas bibliotecas de terceros en PyPi para ello:

• PyCrypto
• RSA Python

Si estás interesado en las matemáticas detrás de él, Python te facilita la experimentación:

code = pow(msg, 65537, 5551201688147) # encode using a public key
plaintext = pow(code, 109182490673, 5551201688147) # decode using a private key

La generación clave es un poco más complicada. Aquí hay un ejemplo simplificado de cómo hacer la generación de claves en memoria usando urandom como fuente de entropía. El código se ejecuta bajo Py2.6 y Py3.x:

import random
def gen_prime(N=10**8, bases=range(2,20000)):
# XXX replace with a more sophisticated algorithm
p = 1
while any(pow(base, p-1, p) != 1 for base in bases):
p = random.SystemRandom().randrange(N)
return p
def multinv(modulus, value):
''''''Multiplicative inverse in a given modulus
>>> multinv(191, 138)
18
>>> 18 * 138 % 191
1
''''''
# http://en.wikipedia.org/wiki/Extended_Euclidean_algorithm
x, lastx = 0, 1
a, b = modulus, value
while b:
a, q, b = b, a // b, a % b
x, lastx = lastx - q * x, x
result = (1 - lastx * modulus) // value
return result + modulus if result < 0 else result
def keygen(N):
''''''Generate public and private keys from primes up to N.
>>> pubkey, privkey = keygen(2**64)
>>> msg = 123456789012345
>>> coded = pow(msg, 65537, pubkey)
>>> plain = pow(coded, privkey, pubkey)
>>> assert msg == plain
''''''
# http://en.wikipedia.org/wiki/RSA
prime1 = gen_prime(N)
prime2 = gen_prime(N)
totient = (prime1 - 1) * (prime2 - 1)
return prime1 * prime2, multinv(totient, 65537)

Answer 3

PyCrypto funciona en Python 3 a partir de 2.4.1.