From d4a1baf6a1a6d4e426849fc945c032e50bf491b6 Mon Sep 17 00:00:00 2001
From: neptunia <kevinshen100@gmail.com>
Date: Sun, 5 Mar 2017 11:36:31 -0500
Subject: [PATCH] fix up prp generator, add another problem

---
 RSA1/description.md        |  1 -
 rsa2/description.md        |  1 +
 {RSA1 => rsa2}/grader.py   | 20 +++++++++++---------
 {RSA1 => rsa2}/problem.yml |  4 ++--
 4 files changed, 14 insertions(+), 12 deletions(-)
 delete mode 100644 RSA1/description.md
 create mode 100644 rsa2/description.md
 rename {RSA1 => rsa2}/grader.py (60%)
 rename {RSA1 => rsa2}/problem.yml (53%)

diff --git a/RSA1/description.md b/RSA1/description.md
deleted file mode 100644
index d44c07b..0000000
--- a/RSA1/description.md
+++ /dev/null
@@ -1 +0,0 @@
-I found somebody's notes on their private RSA! Help me crack [this](${ciphertext_txt}).
\ No newline at end of file
diff --git a/rsa2/description.md b/rsa2/description.md
new file mode 100644
index 0000000..d5802d9
--- /dev/null
+++ b/rsa2/description.md
@@ -0,0 +1 @@
+Some more RSA! This time, there's no P and Q... [this](${ciphertext_txt}).
\ No newline at end of file
diff --git a/RSA1/grader.py b/rsa2/grader.py
similarity index 60%
rename from RSA1/grader.py
rename to rsa2/grader.py
index 9d5b790..bca12b2 100644
--- a/RSA1/grader.py
+++ b/rsa2/grader.py
@@ -1,6 +1,6 @@
 from cStringIO import StringIO
 
-flag = "wh3n_y0u_h4ve_p&q_RSA_iz_ez"
+flag = "l0w_n"
 
 def modx(base,exp,mod):
     r = 1;
@@ -12,23 +12,25 @@ def modx(base,exp,mod):
     return r
 
 def probprime(s):
-    while (modx(2,s-1,s) != 1  or  modx(3,s-1,s) != 1  or modx(5,s-1,s) != 1 or modx(7,s-1,s) != 1):
+    if s%2==0:
         s += 1
+    smolprimes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]
+    while len(set([modx(i,s-1,s) for i in smolprimes])) != 1 or modx(2,s-1,s) != 1:
+        s+=2
     return(s)
 
 def get_problem(random):
     # add Probable Prime function later
-    p = probprime(random.randint(3*10**59,4*10**59))
-    q = probprime(random.randint(3*10**59,4*10**59))
+    p = probprime(random.randint(10**20,9*10**20))
+    q = probprime(random.randint(10**20,9*10**20))
     e = 3
-    salt = "".join([random.choice("0123456789abcdef") for i in range(8)])
+    salt = "".join([random.choice("0123456789abcdef") for i in range(4)])
     return (p, q, e, salt)
 
 def generate_ciphertext(random):
     p, q, e, salt = get_problem(random)
-    encoded = int(("easyctf{%s_%s}" % (flag, salt)).encode('hex'),16)
-    ciphertext =  'p: '+str(p)+'\n'
-    ciphertext += 'q: '+str(q)+'\n'
+    encoded = int(("flag{%s_%s}" % (flag, salt)).encode('hex'),16)
+    ciphertext =  'n: '+str(p*q)+'\n'
     ciphertext += 'e: '+str(e)+'\n'
     ciphertext += 'c: '+str(pow(encoded, e, p*q))+'\n'
 
@@ -36,7 +38,7 @@ def generate_ciphertext(random):
 
 def generate(random):
     return dict(files={
-        "ciphertext_rsa1.txt": generate_ciphertext
+        "ciphertext_rsa2.txt": generate_ciphertext
     })
 
 def grade(random, key):
diff --git a/RSA1/problem.yml b/rsa2/problem.yml
similarity index 53%
rename from RSA1/problem.yml
rename to rsa2/problem.yml
index e46b8d2..210bc96 100644
--- a/RSA1/problem.yml
+++ b/rsa2/problem.yml
@@ -1,4 +1,4 @@
-title: RSA 1
-value: 25
+title: RSA 2
+value: 35
 author: neptunia
 autogen: true
\ No newline at end of file