How do you verify an RSA SHA1 signature in Python?

Question

I\'ve got a string, a signature, and a public key, and I want to verify the signature on the string. The key looks like this:

-----BEGIN PUBLIC KEY-----
MIGf         


        

Answer 1

I try the code given by joeforker but it does not work. Here is my example code and it works fine.

from Crypto.Signature import PKCS1_v1_5
from Crypto.PublicKey import RSA 
from Crypto.Hash import SHA

pem = """-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDfG4IuFO2h/LdDNmonwGNw5srW
nUEWzoBrPRF1NM8LqpOMD45FAPtZ1NmPtHGo0BAS1UsyJEGXx0NPJ8Gw1z+huLrl
XnAVX5B4ec6cJfKKmpL/l94WhP2v8F3OGWrnaEX1mLMoxe124Pcfamt0SPCGkeal
VvXw13PLINE/YptjkQIDAQAB
-----END PUBLIC KEY-----""" # your example key

key = RSA.importKey(pem)
h = SHA.new(self.populateSignStr(params))
verifier = PKCS1_v1_5.new(key)
if verifier.verify(h, signature):
  print "verified"
else:
  print "not verified"