There are many Python toolkits for crypto, so I hope I've done the best choice (at least for now). This is a simple utility class for managing RSA keys, a sort of wrappera to the m2crypto class.
import M2Crypto
class RSA (object):Example usage:
def __init__ (self, bits=1024, padding=M2Crypto.RSA.pkcs1_padding, exp=65537):
self.bits = bits
self.padding = padding
self.exp = exp
self.rsa = None
def generate (self):
self.rsa = M2Crypto.RSA.gen_key(
self.bits, self.exp, lambda x: None)
def encrypt (self, s):
c = ""
bytes = self.bits/8-11
for i in range(0, len(s), bytes):
c += self.rsa.public_encrypt (s[i:i+bytes], self.padding)
return c
def sign (self, s, algo="sha1"):
dgst = M2Crypto.EVP.MessageDigest (algo)
dgst.update (s)
return self.rsa.sign (dgst.digest (), algo)
def verify (self, s, sign, algo="sha1"):
dgst = M2Crypto.EVP.MessageDigest (algo)
dgst.update (s)
try:
self.rsa.verify (dgst.digest (), sign, algo)
except:
return False
return True
def decrypt (self, c):
s = ""
bytes = self.bits/8
for i in range(0, len(c), bytes):
s += self.rsa.private_decrypt (c[i:i+bytes], self.padding)
return s
rsa = RSA ()
rsa.generate () # generate key pair
s = "a"*2000 # test data
edata = rsa.encrypt (s)
sign = rsa.sign (s)
ddata = rsa.decrypt (edata)
assert rsa.verify (ddata, sign) == True
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