From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 26 Sep 2014 13:07:44 +0000 (-0400)
Subject: Comment-out dead code in ed25519/ref10
X-Git-Tag: tor-0.2.6.1-alpha~82
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=27bd1ef100a81235e9d2763c4cf24699251a8008;p=thirdparty%2Ftor.git

Comment-out dead code in ed25519/ref10

There are some loops of the form

       for (i=1;i<1;++i) ...

And of course, if the loop index is initialized to 1, it will never
be less than 1, and the loop body will never be executed.  This
upsets coverity.

Patch fixes CID 1221543 and 1221542
---

diff --git a/src/ext/ed25519/ref10/pow22523.h b/src/ext/ed25519/ref10/pow22523.h
index 60ffe0d34c..9204ff838f 100644
--- a/src/ext/ed25519/ref10/pow22523.h
+++ b/src/ext/ed25519/ref10/pow22523.h
@@ -1,3 +1,4 @@
+/* Modified by Tor: pointless loops removed to appease analysis tools */
 
 /* qhasm: fe z1 */
 
@@ -50,7 +51,7 @@
 /* qhasm: z2 = z1^2^1 */
 /* asm 1: fe_sq(>z2=fe#1,<z1=fe#11); for (i = 1;i < 1;++i) fe_sq(>z2=fe#1,>z2=fe#1); */
 /* asm 2: fe_sq(>z2=t0,<z1=z); for (i = 1;i < 1;++i) fe_sq(>z2=t0,>z2=t0); */
-fe_sq(t0,z); for (i = 1;i < 1;++i) fe_sq(t0,t0);
+fe_sq(t0,z); /* DEADCODE This loop has no effect:  for (i = 1;i < 1;++i) fe_sq(t0,t0); */
 
 /* qhasm: z8 = z2^2^2 */
 /* asm 1: fe_sq(>z8=fe#2,<z2=fe#1); for (i = 1;i < 2;++i) fe_sq(>z8=fe#2,>z8=fe#2); */
@@ -70,7 +71,7 @@ fe_mul(t0,t0,t1);
 /* qhasm: z22 = z11^2^1 */
 /* asm 1: fe_sq(>z22=fe#1,<z11=fe#1); for (i = 1;i < 1;++i) fe_sq(>z22=fe#1,>z22=fe#1); */
 /* asm 2: fe_sq(>z22=t0,<z11=t0); for (i = 1;i < 1;++i) fe_sq(>z22=t0,>z22=t0); */
-fe_sq(t0,t0); for (i = 1;i < 1;++i) fe_sq(t0,t0);
+fe_sq(t0,t0); /* DEADCODE This loop has no effect:  for (i = 1;i < 1;++i) fe_sq(t0,t0); */
 
 /* qhasm: z_5_0 = z9*z22 */
 /* asm 1: fe_mul(>z_5_0=fe#1,<z9=fe#2,<z22=fe#1); */
diff --git a/src/ext/ed25519/ref10/pow225521.h b/src/ext/ed25519/ref10/pow225521.h
index 109df779a2..fe2af94c03 100644
--- a/src/ext/ed25519/ref10/pow225521.h
+++ b/src/ext/ed25519/ref10/pow225521.h
@@ -1,3 +1,4 @@
+/* Modified by Tor: pointless loops removed to appease analysis tools */
 
 /* qhasm: fe z1 */
 
@@ -50,7 +51,7 @@
 /* qhasm: z2 = z1^2^1 */
 /* asm 1: fe_sq(>z2=fe#1,<z1=fe#11); for (i = 1;i < 1;++i) fe_sq(>z2=fe#1,>z2=fe#1); */
 /* asm 2: fe_sq(>z2=t0,<z1=z); for (i = 1;i < 1;++i) fe_sq(>z2=t0,>z2=t0); */
-fe_sq(t0,z); for (i = 1;i < 1;++i) fe_sq(t0,t0);
+fe_sq(t0,z); /* DEADCODE This loop has no effect:  for (i = 1;i < 1;++i) fe_sq(t0,t0); */
 
 /* qhasm: z8 = z2^2^2 */
 /* asm 1: fe_sq(>z8=fe#2,<z2=fe#1); for (i = 1;i < 2;++i) fe_sq(>z8=fe#2,>z8=fe#2); */
@@ -70,7 +71,7 @@ fe_mul(t0,t0,t1);
 /* qhasm: z22 = z11^2^1 */
 /* asm 1: fe_sq(>z22=fe#3,<z11=fe#1); for (i = 1;i < 1;++i) fe_sq(>z22=fe#3,>z22=fe#3); */
 /* asm 2: fe_sq(>z22=t2,<z11=t0); for (i = 1;i < 1;++i) fe_sq(>z22=t2,>z22=t2); */
-fe_sq(t2,t0); for (i = 1;i < 1;++i) fe_sq(t2,t2);
+fe_sq(t2,t0); /* DEADCODE This loop has no effect   for (i = 1;i < 1;++i) fe_sq(t2,t2); */
 
 /* qhasm: z_5_0 = z9*z22 */
 /* asm 1: fe_mul(>z_5_0=fe#2,<z9=fe#2,<z22=fe#3); */