libgpuverify

commit 36724ccea92c0594381774f589bcfa9f73c6d658
parent 6b1ab235f8d80c1ef116f9624ad21910d11ff599
Author: Christian Grothoff <grothoff@gnunet.org>
Date:   Thu,  7 Dec 2023 00:25:36 +0900

-highlight brokenness of MG test

Diffstat:
M
source/montgomery.cl
 | 
74
++++++++++++++------------------------------------------------------------

1 file changed, 14 insertions(+), 60 deletions(-)
diff --git a/source/montgomery.cl b/source/montgomery.cl
@@ -2483,12 +2483,14 @@ __kernel void montgomery(__global void *signature, __global unsigned long *s_off
                          __global unsigned long *pks,
                          unsigned long n)
 {
-    
-    
     int index = get_global_id(0);
     
     int pk = 0;
-    
+     
+    if (1) {
+        printf((__constant char *)"Shortcut on.");
+	return;        
+    }
     while (1) {
         if (pks[pk] >= index)
             break;
@@ -2519,67 +2521,19 @@ __kernel void montgomery(__global void *signature, __global unsigned long *s_off
     
     // the modulus can be assumed to be uneven – always
     if (mpz_even_p(m)) {
-        /*
-        mpz_t bb, x1, x2, q, powj;
-        mpz_init(bb);
-        mpz_init(x1);
-        mpz_init(x2);
-        mpz_init(q);
-        mpz_init(powj);
-        
-        mont_prepare_even_modulus(m, q, powj);
-        
-        // q is uneven, so we can use regular modexp
-        // MARK: we can improve the efficiency here by doing simple reductions
-        
-        mpz_mod(bb, b, q); // reductions like this
-        
-        mont_prepare(bb, e, q, r, r_1, ni, M, x);
-        mont_modexp(xx, x, e, M, q, ni, r, r_1);
-        mont_finish(x1, xx, q, ni, r, r_1);
-        
-        
-        // MARK: we can also reduce and really speed this up as well -> binary method?
-        mpz_powm(x2, b, e, powj);
-        
-        mpz_t y, q_1;
-        mpz_init(y);
-        mpz_init(q_1);
-        
-        mpz_sub(y, x2, x1);
-        
-        mpz_invert(q_1, q, powj);
-        
-        mpz_mul(y, y, q_1);
-        mpz_mod(y, y, powj);
-        
-        mpz_addmul(x1, q, y);
-        
-        mpz_set(res, x1);
-        
-        
-        */
-        
         printf((__constant char *)"An even modulus is not allowed here.");
-        
-    } else {
-        
-        // MARK: prepare might not have to run individually on each kernel (prepare might even run on CPU)
-        mont_prepare(b, e, m, r, r_1, ni, M, x);
-        
-        
-        mont_modexp(xx, x, e, M, m, ni, r, r_1);
-        mont_finish(res, xx, m, ni, r, r_1);
-        
+	return;        
     }
-    
+    if (mpz_even_p(m)) {
+        printf((__constant char *)"An odd modulus is not allowed here.");
+	return;        
+    }
+    // MARK: prepare might not have to run individually on each kernel (prepare might even run on CPU)
+    mont_prepare(b, e, m, r, r_1, ni, M, x);
+    mont_modexp(xx, x, e, M, m, ni, r, r_1);
+    mont_finish(res, xx, m, ni, r, r_1);
     if (mpz_cmp(sig,res) != 0) {
         
         *valid += 1;
-        
     }
-    
-    
-    
-    
 }