SHA256
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forked from pool/libgcrypt
libgcrypt/libgcrypt-secure-EdDSA-session-key.patch
Tomáš Chvátal ef71f17567 Accepting request 500599 from home:pmonrealgonzalez:branches:devel:libraries:c_c++
- Added libgcrypt-secure-EdDSA-session-key.patch [bsc#1042326]
  * Store the session key in secure memory to ensure that constant
    time point operations are used in the MPI library.

OBS-URL: https://build.opensuse.org/request/show/500599
OBS-URL: https://build.opensuse.org/package/show/devel:libraries:c_c++/libgcrypt?expand=0&rev=92
2017-06-03 18:51:04 +00:00

35 lines
1.2 KiB
Diff

From 5a22de904a0a366ae79f03ff1e13a1232a89e26b Mon Sep 17 00:00:00 2001
From: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be>
Date: Thu, 19 Jan 2017 17:00:15 +0100
Subject: [PATCH] ecc: Store EdDSA session key in secure memory.
* cipher/ecc-eddsa.c (_gcry_ecc_eddsa_sign): use mpi_snew to allocate
session key.
--
An attacker who learns the EdDSA session key from side-channel
observation during the signing process, can easily revover the long-
term secret key. Storing the session key in secure memory ensures that
constant time point operations are used in the MPI library.
Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be>
---
cipher/ecc-eddsa.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/cipher/ecc-eddsa.c b/cipher/ecc-eddsa.c
index f91f848..813e030 100644
--- a/cipher/ecc-eddsa.c
+++ b/cipher/ecc-eddsa.c
@@ -603,7 +603,7 @@ _gcry_ecc_eddsa_sign (gcry_mpi_t input, ECC_secret_key *skey,
a = mpi_snew (0);
x = mpi_new (0);
y = mpi_new (0);
- r = mpi_new (0);
+ r = mpi_snew (0);
ctx = _gcry_mpi_ec_p_internal_new (skey->E.model, skey->E.dialect, 0,
skey->E.p, skey->E.a, skey->E.b);
b = (ctx->nbits+7)/8;
--
2.8.0.rc3