improved interface

- Accept key generation size. (not practical above 64-bit)
	- Decrypt from command args only for now
	- Catch Unicode Decode Error cuased by wong key or size.
This commit is contained in:
HeshamTB 2020-04-16 18:56:04 +03:00
parent feeea933c3
commit 1954308cb4
Signed by: Hesham
GPG Key ID: 74876157D199B09E

21
rsa.py
View File

@ -9,10 +9,10 @@ import sys
def main():
if sys.argv[1] == "gen" and len(sys.argv) == 3:
n ,e ,d = generateKeys()
if sys.argv[1] == "gen" and len(sys.argv) == 4: ##rsa gen <keysize> <keyname>
n ,e ,d = generateKeys(int(sys.argv[2]))
key = (n, e, d)
keyFileName = sys.argv[2]
keyFileName = sys.argv[3]
try:
saveKeyFile(key, keyFileName)
except IOError:
@ -30,11 +30,10 @@ def main():
msg_encrypted = encrypt(msg, key_public)
print("Encrypted msg: ", msg_encrypted)
if sys.argv[1] == "decrypt": ##rsa decrypt <cipher> <key>
fileName = sys.argv[2]
cipher = int(sys.argv[2])
key = readKeyFile(sys.argv[3])
cipher = int()
with open(fileName, "r") as cipherFile:
cipher = int(cipherFile.readline()) ##one line may make problems later with padding
#with open(fileName, "r") as cipherFile:
# cipher = int(cipherFile.readline()) ##one line may make problems later with padding
msg = decrypt(cipher, key[2],key[0])
print("Decrypted message: ", msg)
@ -84,13 +83,17 @@ def decrypt(cipher, privateKey, n):
d = privateKey
msg_decrypted_number_form = pow(msg_encrypted_number_form, d, n) # m = c^d mod n
msg_decrypted = int(msg_decrypted_number_form)
msg_decrypted = str(msg_decrypted.to_bytes(msg_decrypted.bit_length(), "little").decode()).strip()
try:
msg_decrypted = str(msg_decrypted.to_bytes(msg_decrypted.bit_length(), "little").decode()).strip()
except UnicodeDecodeError:
print("Cant decrypt properly")
return msg_decrypted
def getPrime(bits):
while True:
#Byte order "little" or "big" does not matter here since we want a random number from os.urandom()
x = int.from_bytes(os.urandom(int(bits/8)),"little")
print("trying: ", x)
if isPrime(x):
return x
@ -119,7 +122,7 @@ def isPrime(number):
def readKeyFile(keyName):
key = tuple()
with open(keyName, "r") as keyFile:
with open(keyName, "rb") as keyFile:
tempkey = keyFile.readlines()
key = (int(tempkey[0].strip()), int(tempkey[1].strip()), int(tempkey[2].strip()))
return key