components/golang/patches/0074-crypto-dsa-eliminate-invalid-PublicKey-early.patch
From 2cfbb875208f4acecfb0b72de5aebe37e8d03a35 Mon Sep 17 00:00:00 2001
From: Robert Griesemer <[email protected]>
Date: Tue, 5 Apr 2016 09:44:00 -0700
Subject: [PATCH 74/79] crypto/dsa: eliminate invalid PublicKey early
For PublicKey.P == 0, Verify will fail. Don't even try.
Change-Id: I1009f2b3dead8d0041626c946633acb10086d8c8
Reviewed-on: https://go-review.googlesource.com/21533
Reviewed-by: Brad Fitzpatrick <[email protected]>
Run-TryBot: Brad Fitzpatrick <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-on: https://go-review.googlesource.com/21637
---
src/crypto/dsa/dsa.go | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/src/crypto/dsa/dsa.go b/src/crypto/dsa/dsa.go
index b7565a6..0ecb24a 100644
--- a/src/crypto/dsa/dsa.go
+++ b/src/crypto/dsa/dsa.go
@@ -249,6 +249,10 @@ func Sign(rand io.Reader, priv *PrivateKey, hash []byte) (r, s *big.Int, err err
func Verify(pub *PublicKey, hash []byte, r, s *big.Int) bool {
// FIPS 186-3, section 4.7
+ if pub.P.Sign() == 0 {
+ return false
+ }
+
if r.Sign() < 1 || r.Cmp(pub.Q) >= 0 {
return false
}
--
2.7.4