commit 27bd1ef100a81235e9d2763c4cf24699251a8008 Author: Nick Mathewson nickm@torproject.org Date: Fri Sep 26 09:07:44 2014 -0400

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 --- src/ext/ed25519/ref10/pow22523.h | 5 +++-- src/ext/ed25519/ref10/pow225521.h | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/ext/ed25519/ref10/pow22523.h b/src/ext/ed25519/ref10/pow22523.h index 60ffe0d..9204ff8 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 109df77..fe2af94 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); */