RSA sign and verify functions

Python PyCrypto: Sign Data Example.py

'''
pip uninstall crypto
pip install pycrypto
Tested using python 3
'''
def sign_data(private_key_loc, data, pass_phrase=None):
    '''
    param: private_key_loc Path to your private key
    param: data, plain text data to be signed
    param: pass_phrase if private key is protected
    return: base64 encoded signature
    '''
    from Crypto.PublicKey import RSA 
    from Crypto.Signature import PKCS1_v1_5 
    from Crypto.Hash import SHA256 
    from base64 import b64encode, b64decode 
    key = open(private_key_loc, "r").read()
    rsakey=RSA.importKey(key,passphrase=pass_phrase)
    signer = PKCS1_v1_5.new(rsakey) 
    digest = SHA256.new() 
    # It's being assumed the data is base64 encoded, so it's decoded before updating the digest 
    digest.update(data.encode('utf-8')) 
    sign = signer.sign(digest) 
    return b64encode(sign)

def verify_sign(public_key_loc, signature, data):
    '''
    Verifies with a public key from whom the data came that it was indeed 
    signed by their private key
    param: public_key_loc Path to public key
    param: signature String signature to be verified
    param: data, plain text data from which signature is derived from
    return: Boolean. True if the signature is valid; False otherwise. 
    '''
    from Crypto.PublicKey import RSA 
    from Crypto.Signature import PKCS1_v1_5 
    from Crypto.Hash import SHA256 
    from base64 import b64decode 
    pub_key = open(public_key_loc, "r").read() 
    rsakey = RSA.importKey(pub_key) 
    signer = PKCS1_v1_5.new(rsakey) 
    digest = SHA256.new() 
    # Assumes the data is base64 encoded to begin with
    digest.update(data.encode('utf-8'))
    if signer.verify(digest, b64decode(signature)):
        return True
    return False