Skip to content

Commit 7d26ba7

Browse files
ruppysuppygithub-actions
ruppysuppy
and
github-actions
authored
Added diffie-hellman algorithm (#4128)
* updating DIRECTORY.md * feat: added diffie-hellman key exchange algorithm * fix: enforce maxline length = 88 * fix: fixed import order * fix: used flake to correct styling * updating DIRECTORY.md Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
1 parent 0728cf1 commit 7d26ba7

File tree

2 files changed

+273
-1
lines changed

2 files changed

+273
-1
lines changed

Diff for: ‎DIRECTORY.md

+2-1
Original file line numberDiff line numberDiff line change
@@ -59,6 +59,7 @@
5959
* [Decrypt Caesar With Chi Squared](https://github.com/TheAlgorithms/Python/blob/master/ciphers/decrypt_caesar_with_chi_squared.py)
6060
* [Deterministic Miller Rabin](https://github.com/TheAlgorithms/Python/blob/master/ciphers/deterministic_miller_rabin.py)
6161
* [Diffie](https://github.com/TheAlgorithms/Python/blob/master/ciphers/diffie.py)
62+
* [Diffie Hellman](https://github.com/TheAlgorithms/Python/blob/master/ciphers/diffie_hellman.py)
6263
* [Elgamal Key Generator](https://github.com/TheAlgorithms/Python/blob/master/ciphers/elgamal_key_generator.py)
6364
* [Enigma Machine2](https://github.com/TheAlgorithms/Python/blob/master/ciphers/enigma_machine2.py)
6465
* [Hill Cipher](https://github.com/TheAlgorithms/Python/blob/master/ciphers/hill_cipher.py)
@@ -224,7 +225,6 @@
224225
* [Abbreviation](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/abbreviation.py)
225226
* [Bitmask](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/bitmask.py)
226227
* [Climbing Stairs](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/climbing_stairs.py)
227-
* [Coin Change](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/coin_change.py)
228228
* [Edit Distance](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/edit_distance.py)
229229
* [Factorial](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/factorial.py)
230230
* [Fast Fibonacci](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/fast_fibonacci.py)
@@ -243,6 +243,7 @@
243243
* [Max Non Adjacent Sum](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/max_non_adjacent_sum.py)
244244
* [Max Sub Array](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/max_sub_array.py)
245245
* [Max Sum Contiguous Subsequence](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/max_sum_contiguous_subsequence.py)
246+
* [Minimum Coin Change](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/minimum_coin_change.py)
246247
* [Minimum Cost Path](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/minimum_cost_path.py)
247248
* [Minimum Partition](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/minimum_partition.py)
248249
* [Minimum Steps To One](https://github.com/TheAlgorithms/Python/blob/master/dynamic_programming/minimum_steps_to_one.py)

Diff for: ‎ciphers/diffie_hellman.py

+271
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,271 @@
1+
from binascii import hexlify
2+
from hashlib import sha256
3+
from os import urandom
4+
5+
# RFC 3526 - More Modular Exponential (MODP) Diffie-Hellman groups for
6+
# Internet Key Exchange (IKE) https://tools.ietf.org/html/rfc3526
7+
8+
primes = {
9+
# 1536-bit
10+
5: {
11+
"prime": int(
12+
"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
13+
+ "29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
14+
+ "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
15+
+ "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
16+
+ "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
17+
+ "C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
18+
+ "83655D23DCA3AD961C62F356208552BB9ED529077096966D"
19+
+ "670C354E4ABC9804F1746C08CA237327FFFFFFFFFFFFFFFF",
20+
base=16,
21+
),
22+
"generator": 2,
23+
},
24+
# 2048-bit
25+
14: {
26+
"prime": int(
27+
"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
28+
+ "29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
29+
+ "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
30+
+ "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
31+
+ "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
32+
+ "C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
33+
+ "83655D23DCA3AD961C62F356208552BB9ED529077096966D"
34+
+ "670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B"
35+
+ "E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9"
36+
+ "DE2BCBF6955817183995497CEA956AE515D2261898FA0510"
37+
+ "15728E5A8AACAA68FFFFFFFFFFFFFFFF",
38+
base=16,
39+
),
40+
"generator": 2,
41+
},
42+
# 3072-bit
43+
15: {
44+
"prime": int(
45+
"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
46+
+ "29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
47+
+ "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
48+
+ "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
49+
+ "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
50+
+ "C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
51+
+ "83655D23DCA3AD961C62F356208552BB9ED529077096966D"
52+
+ "670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B"
53+
+ "E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9"
54+
+ "DE2BCBF6955817183995497CEA956AE515D2261898FA0510"
55+
+ "15728E5A8AAAC42DAD33170D04507A33A85521ABDF1CBA64"
56+
+ "ECFB850458DBEF0A8AEA71575D060C7DB3970F85A6E1E4C7"
57+
+ "ABF5AE8CDB0933D71E8C94E04A25619DCEE3D2261AD2EE6B"
58+
+ "F12FFA06D98A0864D87602733EC86A64521F2B18177B200C"
59+
+ "BBE117577A615D6C770988C0BAD946E208E24FA074E5AB31"
60+
+ "43DB5BFCE0FD108E4B82D120A93AD2CAFFFFFFFFFFFFFFFF",
61+
base=16,
62+
),
63+
"generator": 2,
64+
},
65+
# 4096-bit
66+
16: {
67+
"prime": int(
68+
"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
69+
+ "29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
70+
+ "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
71+
+ "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
72+
+ "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
73+
+ "C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
74+
+ "83655D23DCA3AD961C62F356208552BB9ED529077096966D"
75+
+ "670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B"
76+
+ "E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9"
77+
+ "DE2BCBF6955817183995497CEA956AE515D2261898FA0510"
78+
+ "15728E5A8AAAC42DAD33170D04507A33A85521ABDF1CBA64"
79+
+ "ECFB850458DBEF0A8AEA71575D060C7DB3970F85A6E1E4C7"
80+
+ "ABF5AE8CDB0933D71E8C94E04A25619DCEE3D2261AD2EE6B"
81+
+ "F12FFA06D98A0864D87602733EC86A64521F2B18177B200C"
82+
+ "BBE117577A615D6C770988C0BAD946E208E24FA074E5AB31"
83+
+ "43DB5BFCE0FD108E4B82D120A92108011A723C12A787E6D7"
84+
+ "88719A10BDBA5B2699C327186AF4E23C1A946834B6150BDA"
85+
+ "2583E9CA2AD44CE8DBBBC2DB04DE8EF92E8EFC141FBECAA6"
86+
+ "287C59474E6BC05D99B2964FA090C3A2233BA186515BE7ED"
87+
+ "1F612970CEE2D7AFB81BDD762170481CD0069127D5B05AA9"
88+
+ "93B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934063199"
89+
+ "FFFFFFFFFFFFFFFF",
90+
base=16,
91+
),
92+
"generator": 2,
93+
},
94+
# 6144-bit
95+
17: {
96+
"prime": int(
97+
"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E08"
98+
+ "8A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B"
99+
+ "302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9"
100+
+ "A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE6"
101+
+ "49286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8"
102+
+ "FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D"
103+
+ "670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C"
104+
+ "180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF695581718"
105+
+ "3995497CEA956AE515D2261898FA051015728E5A8AAAC42DAD33170D"
106+
+ "04507A33A85521ABDF1CBA64ECFB850458DBEF0A8AEA71575D060C7D"
107+
+ "B3970F85A6E1E4C7ABF5AE8CDB0933D71E8C94E04A25619DCEE3D226"
108+
+ "1AD2EE6BF12FFA06D98A0864D87602733EC86A64521F2B18177B200C"
109+
+ "BBE117577A615D6C770988C0BAD946E208E24FA074E5AB3143DB5BFC"
110+
+ "E0FD108E4B82D120A92108011A723C12A787E6D788719A10BDBA5B26"
111+
+ "99C327186AF4E23C1A946834B6150BDA2583E9CA2AD44CE8DBBBC2DB"
112+
+ "04DE8EF92E8EFC141FBECAA6287C59474E6BC05D99B2964FA090C3A2"
113+
+ "233BA186515BE7ED1F612970CEE2D7AFB81BDD762170481CD0069127"
114+
+ "D5B05AA993B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934028492"
115+
+ "36C3FAB4D27C7026C1D4DCB2602646DEC9751E763DBA37BDF8FF9406"
116+
+ "AD9E530EE5DB382F413001AEB06A53ED9027D831179727B0865A8918"
117+
+ "DA3EDBEBCF9B14ED44CE6CBACED4BB1BDB7F1447E6CC254B33205151"
118+
+ "2BD7AF426FB8F401378CD2BF5983CA01C64B92ECF032EA15D1721D03"
119+
+ "F482D7CE6E74FEF6D55E702F46980C82B5A84031900B1C9E59E7C97F"
120+
+ "BEC7E8F323A97A7E36CC88BE0F1D45B7FF585AC54BD407B22B4154AA"
121+
+ "CC8F6D7EBF48E1D814CC5ED20F8037E0A79715EEF29BE32806A1D58B"
122+
+ "B7C5DA76F550AA3D8A1FBFF0EB19CCB1A313D55CDA56C9EC2EF29632"
123+
+ "387FE8D76E3C0468043E8F663F4860EE12BF2D5B0B7474D6E694F91E"
124+
+ "6DCC4024FFFFFFFFFFFFFFFF",
125+
base=16,
126+
),
127+
"generator": 2,
128+
},
129+
# 8192-bit
130+
18: {
131+
"prime": int(
132+
"FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1"
133+
+ "29024E088A67CC74020BBEA63B139B22514A08798E3404DD"
134+
+ "EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245"
135+
+ "E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED"
136+
+ "EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D"
137+
+ "C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F"
138+
+ "83655D23DCA3AD961C62F356208552BB9ED529077096966D"
139+
+ "670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B"
140+
+ "E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9"
141+
+ "DE2BCBF6955817183995497CEA956AE515D2261898FA0510"
142+
+ "15728E5A8AAAC42DAD33170D04507A33A85521ABDF1CBA64"
143+
+ "ECFB850458DBEF0A8AEA71575D060C7DB3970F85A6E1E4C7"
144+
+ "ABF5AE8CDB0933D71E8C94E04A25619DCEE3D2261AD2EE6B"
145+
+ "F12FFA06D98A0864D87602733EC86A64521F2B18177B200C"
146+
+ "BBE117577A615D6C770988C0BAD946E208E24FA074E5AB31"
147+
+ "43DB5BFCE0FD108E4B82D120A92108011A723C12A787E6D7"
148+
+ "88719A10BDBA5B2699C327186AF4E23C1A946834B6150BDA"
149+
+ "2583E9CA2AD44CE8DBBBC2DB04DE8EF92E8EFC141FBECAA6"
150+
+ "287C59474E6BC05D99B2964FA090C3A2233BA186515BE7ED"
151+
+ "1F612970CEE2D7AFB81BDD762170481CD0069127D5B05AA9"
152+
+ "93B4EA988D8FDDC186FFB7DC90A6C08F4DF435C934028492"
153+
+ "36C3FAB4D27C7026C1D4DCB2602646DEC9751E763DBA37BD"
154+
+ "F8FF9406AD9E530EE5DB382F413001AEB06A53ED9027D831"
155+
+ "179727B0865A8918DA3EDBEBCF9B14ED44CE6CBACED4BB1B"
156+
+ "DB7F1447E6CC254B332051512BD7AF426FB8F401378CD2BF"
157+
+ "5983CA01C64B92ECF032EA15D1721D03F482D7CE6E74FEF6"
158+
+ "D55E702F46980C82B5A84031900B1C9E59E7C97FBEC7E8F3"
159+
+ "23A97A7E36CC88BE0F1D45B7FF585AC54BD407B22B4154AA"
160+
+ "CC8F6D7EBF48E1D814CC5ED20F8037E0A79715EEF29BE328"
161+
+ "06A1D58BB7C5DA76F550AA3D8A1FBFF0EB19CCB1A313D55C"
162+
+ "DA56C9EC2EF29632387FE8D76E3C0468043E8F663F4860EE"
163+
+ "12BF2D5B0B7474D6E694F91E6DBE115974A3926F12FEE5E4"
164+
+ "38777CB6A932DF8CD8BEC4D073B931BA3BC832B68D9DD300"
165+
+ "741FA7BF8AFC47ED2576F6936BA424663AAB639C5AE4F568"
166+
+ "3423B4742BF1C978238F16CBE39D652DE3FDB8BEFC848AD9"
167+
+ "22222E04A4037C0713EB57A81A23F0C73473FC646CEA306B"
168+
+ "4BCBC8862F8385DDFA9D4B7FA2C087E879683303ED5BDD3A"
169+
+ "062B3CF5B3A278A66D2A13F83F44F82DDF310EE074AB6A36"
170+
+ "4597E899A0255DC164F31CC50846851DF9AB48195DED7EA1"
171+
+ "B1D510BD7EE74D73FAF36BC31ECFA268359046F4EB879F92"
172+
+ "4009438B481C6CD7889A002ED5EE382BC9190DA6FC026E47"
173+
+ "9558E4475677E9AA9E3050E2765694DFC81F56E880B96E71"
174+
+ "60C980DD98EDD3DFFFFFFFFFFFFFFFFF",
175+
base=16,
176+
),
177+
"generator": 2,
178+
},
179+
}
180+
181+
182+
class DiffieHellman:
183+
"""
184+
Class to represent the Diffie-Hellman key exchange protocol
185+
186+
187+
>>> alice = DiffieHellman()
188+
>>> bob = DiffieHellman()
189+
190+
>>> alice_private = alice.get_private_key()
191+
>>> alice_public = alice.generate_public_key()
192+
193+
>>> bob_private = bob.get_private_key()
194+
>>> bob_public = bob.generate_public_key()
195+
196+
>>> # generating shared key using the DH object
197+
>>> alice_shared = alice.generate_shared_key(bob_public)
198+
>>> bob_shared = bob.generate_shared_key(alice_public)
199+
200+
>>> assert alice_shared == bob_shared
201+
202+
>>> # generating shared key using static methods
203+
>>> alice_shared = DiffieHellman.generate_shared_key_static(
204+
... alice_private, bob_public
205+
... )
206+
>>> bob_shared = DiffieHellman.generate_shared_key_static(
207+
... bob_private, alice_public
208+
... )
209+
210+
>>> assert alice_shared == bob_shared
211+
"""
212+
213+
# Current minimum recommendation is 2048 bit (group 14)
214+
def __init__(self, group: int = 14) -> None:
215+
if group not in primes:
216+
raise ValueError("Unsupported Group")
217+
self.prime = primes[group]["prime"]
218+
self.generator = primes[group]["generator"]
219+
220+
self.__private_key = int(hexlify(urandom(32)), base=16)
221+
222+
def get_private_key(self) -> str:
223+
return hex(self.__private_key)[2:]
224+
225+
def generate_public_key(self) -> str:
226+
public_key = pow(self.generator, self.__private_key, self.prime)
227+
return hex(public_key)[2:]
228+
229+
def is_valid_public_key(self, key: int) -> bool:
230+
# check if the other public key is valid based on NIST SP800-56
231+
if 2 <= key and key <= self.prime - 2:
232+
if pow(key, (self.prime - 1) // 2, self.prime) == 1:
233+
return True
234+
return False
235+
236+
def generate_shared_key(self, other_key_str: str) -> str:
237+
other_key = int(other_key_str, base=16)
238+
if not self.is_valid_public_key(other_key):
239+
raise ValueError("Invalid public key")
240+
shared_key = pow(other_key, self.__private_key, self.prime)
241+
return sha256(str(shared_key).encode()).hexdigest()
242+
243+
@staticmethod
244+
def is_valid_public_key_static(
245+
local_private_key_str: str, remote_public_key_str: str, prime: int
246+
) -> bool:
247+
# check if the other public key is valid based on NIST SP800-56
248+
if 2 <= remote_public_key_str and remote_public_key_str <= prime - 2:
249+
if pow(remote_public_key_str, (prime - 1) // 2, prime) == 1:
250+
return True
251+
return False
252+
253+
@staticmethod
254+
def generate_shared_key_static(
255+
local_private_key_str: str, remote_public_key_str: str, group: int = 14
256+
) -> str:
257+
local_private_key = int(local_private_key_str, base=16)
258+
remote_public_key = int(remote_public_key_str, base=16)
259+
prime = primes[group]["prime"]
260+
if not DiffieHellman.is_valid_public_key_static(
261+
local_private_key, remote_public_key, prime
262+
):
263+
raise ValueError("Invalid public key")
264+
shared_key = pow(remote_public_key, local_private_key, prime)
265+
return sha256(str(shared_key).encode()).hexdigest()
266+
267+
268+
if __name__ == "__main__":
269+
import doctest
270+
271+
doctest.testmod()

0 commit comments

Comments
 (0)