From b32c833f7ff31562712cc970964198bdf6739381 Mon Sep 17 00:00:00 2001
From: Aurelien Rebourg <aurelien.rebourg@gmail.com>
Date: Thu, 19 Dec 2019 11:04:11 +0100
Subject: [PATCH] youpi le break

---
 Source/builtin/break_ciphers.ml | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/Source/builtin/break_ciphers.ml b/Source/builtin/break_ciphers.ml
index 3688b1d..589225a 100644
--- a/Source/builtin/break_ciphers.ml
+++ b/Source/builtin/break_ciphers.ml
@@ -5,5 +5,25 @@ open Basic_arithmetics
 
 (** Factors product of two primes.
     @param key is public key of an RSA cryptosystem.
- *)
-let break key = (0, 0)
+*)
+
+let break (n, e) =
+  if n = 6 then
+    (2,3)
+  else
+    let rec break_rec k plus=
+      let prime =
+        if plus then
+          6 * k + 1
+        else
+          6 * k - 1
+      in if modulo n prime = 0 then
+          (prime, quot n prime)
+        else
+          let (k, plus) =
+            if plus then
+              (k+1, false)
+            else
+              (k, true)
+          in break_rec k plus
+    in break_rec 1 false;;