It's Not My Fault 1

its_not_my_fault_1/not_my_fault.py

@@ -0,0 +1,61 @@
+#!python3
+import random
+import string
+import hashlib
+import time
+
+from Crypto.Util.number import inverse, getPrime, bytes_to_long, GCD
+from sympy.ntheory.modular import solve_congruence
+
+FLAG = open('flag.txt', 'r').read()
+
+def CRT(a, m, b, n):
+    val, mod = solve_congruence((a, m), (b, n))
+    return val
+
+def gen_key():
+    while True:
+        p = getPrime(512)
+        q = getPrime(512)
+        if GCD(p-1, q-1) == 2:
+            return p, q
+
+def get_clue(p, q, BITS):
+    while True:
+        d_p = random.randint(1, 1 << BITS)
+        d_q = random.randint(1, q - 1)
+        if d_p % 2 == d_q % 2:
+            d = CRT(d_p, p - 1, d_q, q - 1)
+            e = inverse(d, (p - 1) * (q - 1))
+            print("Clue : ", e)
+            return
+
+def get_flag(p, q):
+    start = time.time()
+    ans = int(input())
+    if (time.time() - start) > (15 * 60):
+        print("Too long!")
+        exit()
+    else:
+        if ans == p + q:
+            print(FLAG)
+        else:
+            print("oops...")
+
+
+#PoW
+
+vals1 = "".join([random.choice(string.digits) for _ in range(5)])
+vals2 = "".join([random.choice(string.hexdigits.lower()) for _ in range(6)])
+vals1 = "63494"
+vals2 = "c8ecb7"
+user_input = input("Enter a string that starts with \"{}\" (no quotes) which creates an md5 hash that ends in these six hex digits: {}\n".format(vals1, vals2))
+user_hash = hashlib.md5(user_input.encode()).hexdigest()
+
+if user_input[:5] == vals1 and user_hash[-6:] == vals2:
+    p, q = gen_key()
+    n = p * q
+    print("Public Modulus : ", n)
+    get_clue(p, q, 20)
+    get_flag(p, q)
+