263 lines
8.4 KiB
Python
Executable File
263 lines
8.4 KiB
Python
Executable File
#!/usr/bin/python3
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#program to generate rsa key pair using methods in EE-305
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# Hesham Banafa
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"""
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Large Prime check: https://www.alpertron.com.ar/ECM.HTM
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To crack a key, find p or q through n. (prime factorazation)
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Another way to find p or q from the private key:
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https://crypto.stackexchange.com/questions/13113/how-can-i-find-the-prime-numbers-used-in-rsa
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"""
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import math
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import os
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import sys
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import MillerRabin as mr
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keysFolder = "keys/"
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byteOrder = "little"
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N=0
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E=1
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D=2
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P=3
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Q=4
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PHI=5
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ID=6
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def main():
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if len(sys.argv) > 1:
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if sys.argv[1] == "gen": ##rsa gen <keysize> <keyname>
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keyFileName = sys.argv[3]
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key = generateKeys(keyFileName, int(sys.argv[2]))
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printKey(key)
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try:
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saveKeyFile(key, keyFileName)
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except IOError:
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print("could not write file")
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exit(1)
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except Exception as ex:
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print(ex)
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exit(1)
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exit(0)
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if sys.argv[1] == "encrypt": ##rsa encrypt <message> <key> <signer>
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if len(sys.argv) == 5:
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msg = sys.argv[2]
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msg_list = msg.split()
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keyName = sys.argv[3]
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signing_key_name = sys.argv[4]
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key = readKeyFile(keyName)
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signing_key = readKeyFile(signing_key_name)
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key_public = (key[N], key[E])
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msg_encrypted = ""
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for word in msg_list:
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msg_encrypted = msg_encrypted + " " + str(encrypt(word, key_public))
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#msg_encrypted = encrypt(msg, key_public)
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print("Encrypted msg: \n", msg_encrypted)
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print("Signed: \n", sign(msg_encrypted, signing_key)) ## Adds an encrypted sig at the end of message.
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else:
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print("Not enough arguments")
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print("rsa encrypt <message> <key> <signer>")
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#Make help function
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exit(0)
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if sys.argv[1] == "decrypt": ##rsa decrypt "<cipher>" <key>
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if len(sys.argv) == 4:
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cipher = sys.argv[2]
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cipher_list = cipher.split()
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sig = verify(cipher_list)
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del cipher_list[-1]
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msg_decrypted = ""
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key = readKeyFile(sys.argv[3])
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for cipher_word in cipher_list:
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msg_decrypted = msg_decrypted + " " + str(decrypt(int(cipher_word),key[D],key[N]))
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print("Signed by: ", sig)
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print("Decrypted message: \n", msg_decrypted)
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else:
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print("Not enough arguments")
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print("rsa decrypt \"<cipher>\" <key>")
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exit(0)
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if sys.argv[1] == "list":
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listKeys()
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exit(0)
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if sys.argv[1] == "export": #rsa export <key>
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key_file_name = sys.argv[2]
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exportKey(key_file_name)
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exit(0)
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#No command exit code
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exit(127)
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def generateKeys(id, bits=64):
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from multiprocessing.pool import Pool
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#Primes of size 32 bit random
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#resulting in a 64-bit key mod
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pool = Pool()
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result1 = pool.apply_async(getPrime, [int(bits/2)])
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result2 = pool.apply_async(getPrime, [int(bits/2)])
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p = result1.get()
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q = result2.get()
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n = p*q
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#print("n: ", n)
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#lamda(n) = LCM(p-1, q-1)
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#Since LCM(a,b) = ab/GCD(a,b)
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#gcd = math.gcd(p-1, q-1)
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#print("GCD: ", gcd)
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#lcm = abs((p-1) * (q-1)) / gcd
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#print("LCM: ", lcm)
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phi = (p-1)*(q-1)
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#print("phi: ", phi)
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#e exponant should be 1 < e < lamda(n) and GCD(e, lamda(n)) = 1 (coprime)
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# recommended value is 65,537
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e = 65537
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d = pow(e,-1,phi) # d = e^-1 mod phi
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return (n, e, d, p, q, phi, id)
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def encrypt(message, publicKey):
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msg_text = message
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n = publicKey[N]
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e = publicKey[E]
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print("using n: {0}, e: {1}".format(n, e))
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msg_number_form = int.from_bytes(msg_text.encode(), byteOrder)
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print("Word: %s or %d" % (msg_text, msg_number_form))
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msg_encrypted_number_form = pow(msg_number_form, e, n) # c = msg^e mod n
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return msg_encrypted_number_form
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def decrypt(cipher, privateKey, n):
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msg_encrypted_number_form = cipher
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d = privateKey
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msg_decrypted_number_form = pow(msg_encrypted_number_form, d, n) # msg = c^d mod n
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msg_decrypted = int(msg_decrypted_number_form)
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try:
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msg_decrypted = str(msg_decrypted.to_bytes(msg_decrypted.bit_length(), byteOrder).decode()).strip()
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except UnicodeDecodeError:
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print("Cant decrypt properly")
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return msg_decrypted
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def getPrime(bits):
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while True:
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#Byte order "little" or "big" does not matter here since we want a random number from os.urandom()
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x = int.from_bytes(os.urandom(int(bits/8)), byteOrder)
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print("trying: ", x, end="")
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if mr.is_prime(x):
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print("\nprime: ", x)
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return x
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print("\r",end="")
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def isPrime(number):
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if number == 2:
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return True
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#if 2 devides number then num is not prime. pg.21
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if number % 2 == 0 or number == 1:
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return False
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#largest integer less than or equal square root of number (K)
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rootOfNum = math.sqrt(number)
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K = math.floor(rootOfNum)
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#Take odd D such that 1 < D <= K
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#If D devides number then number is not prime. otherwise prime.
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for D in range(1, K, 2):
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if D % 2 == 0 or D == 1:
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pass
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else:
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if number % D == 0 or number % 5 == 0:
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return False
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return True
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def sign(encrypted_msg, key):
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enc_msg = str(encrypted_msg)
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encrypted_msg_list = enc_msg.split()
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enc_sig = encrypt("sig:"+key[ID], (key[N], key[D]))
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encrypted_msg_list.append(enc_sig)
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signed_msg = ""
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for word in encrypted_msg_list:
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signed_msg = str(signed_msg) + " " + str(word)
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return signed_msg.strip()
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def verify(cipher_list):
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sig = "Unknown"
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local_keys = os.listdir(keysFolder)
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cipher_list.reverse() #To get last word using index 0
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encrypted_sig = cipher_list[0]
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cipher_list.reverse()
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for key_name in local_keys:
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key = readKeyFile(key_name)
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print("Found key: ", key_name)
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sig = str(decrypt(int(encrypted_sig), key[E], key[N]))
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if "sig:" in sig:
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return sig.replace("sig:","")
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def readKeyFile(keyName):
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key = tuple()
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with open(keysFolder+keyName, "r") as keyFile:
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tempkey = keyFile.readlines()
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if len(tempkey) == 3: #means it only public part (n, e, id)
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key = (int(tempkey[N].strip(), 16), int(tempkey[E].strip(), 16), 0, 0, 0, 0, tempkey[2])
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else: #Make this a loop from 0 to 5
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key = (int(tempkey[N].strip(), 16),
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int(tempkey[E].strip(), 16),
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int(tempkey[D].strip(), 16),
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int(tempkey[P].strip(), 16),
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int(tempkey[Q].strip(), 16),
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int(tempkey[PHI].strip(), 16),
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str(tempkey[ID].strip()))
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return key
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def saveKeyFile(key, fileName):
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if not os.path.isdir(keysFolder):
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os.makedirs(keysFolder)
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with open(keysFolder+fileName, "w") as keyFile:
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for entry in range(0, 6):
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if key[entry] != 0:
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keyFile.write(hex(key[entry])+"\n")
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else:
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pass
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keyFile.write(key[ID]+"\n")
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def printKey(key):
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n = key[N]
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e = key[E]
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d = key[D]
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id = key[ID]
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print("----------------------------------------------"+
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"\nID: {}".format(id) +
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"\n{}-BIT KEY".format(n.bit_length())+
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"\nPUBLIC PART:"+
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"\n{0}/{1}".format(hex(n), hex(e))+
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"\nPTIVATE PART:"+
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"\n{0}".format(hex(d))+
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"\n----------------------------------------------",
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)
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def listKeys():
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if not os.path.isdir(keysFolder):
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os.makedirs(keysFolder)
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local_keys = os.listdir(keysFolder)
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if len(local_keys) == 0:
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print("Cant find local keys.")
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return
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print("ID PRIVATE SIZE")
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print("-------------------------")
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for keyName in local_keys:
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key = readKeyFile(keyName)
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if key[D] == 0:
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check = "".strip()
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else: check = '\u2713'
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print("%7s%7s%7s-bit" % (key[ID].strip(), check, key[N].bit_length()))
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def exportKey(keyFileName):
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key = readKeyFile(keyFileName)
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public_key = (key[N], key[E], 0, 0, 0, 0, key[ID])
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saveKeyFile(public_key, key[ID]+"-public")
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print("Saved public form of key {} in keys folder".format(key[ID]))
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if __name__ == "__main__":
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main() |