In Libgcrypt before 1.7.7, an attacker who learns the EdDSA session key (from side-channel observation during the signing process) can easily recover the long-term secret key. 1.7.7 makes a cipher/ecc-eddsa.c change to store this session key in secure memory, to ensure that constant-time point operations are used in the MPI library.
References: https://nvd.nist.gov/vuln/detail/CVE-2017-9526 Upstream patch: https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commitdiff;h=5a22de904a0a366ae79f03ff1e13a1232a89e26b Signed-off-by: Ovidiu Panait <ovpan...@gmail.com> --- .../libgcrypt/files/CVE-2017-9526.patch | 36 ++++++++++++++++++++++ meta/recipes-support/libgcrypt/libgcrypt.inc | 1 + 2 files changed, 37 insertions(+) create mode 100644 meta/recipes-support/libgcrypt/files/CVE-2017-9526.patch diff --git a/meta/recipes-support/libgcrypt/files/CVE-2017-9526.patch b/meta/recipes-support/libgcrypt/files/CVE-2017-9526.patch new file mode 100644 index 0000000..26b570f --- /dev/null +++ b/meta/recipes-support/libgcrypt/files/CVE-2017-9526.patch @@ -0,0 +1,36 @@ +From 5a22de904a0a366ae79f03ff1e13a1232a89e26b Mon Sep 17 00:00:00 2001 +From: Jo Van Bulck <jo.vanbu...@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. + +Upstream-Status: Backport +CVE: CVE-2017-9526 + +Signed-off-by: Jo Van Bulck <jo.vanbu...@cs.kuleuven.be> +Signed-off-by: Ovidiu Panait <ovpan...@gmail.com> +--- + 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; +-- +2.7.4 + diff --git a/meta/recipes-support/libgcrypt/libgcrypt.inc b/meta/recipes-support/libgcrypt/libgcrypt.inc index 3c7e89a..d6d5bd9 100644 --- a/meta/recipes-support/libgcrypt/libgcrypt.inc +++ b/meta/recipes-support/libgcrypt/libgcrypt.inc @@ -20,6 +20,7 @@ SRC_URI = "${GNUPG_MIRROR}/libgcrypt/libgcrypt-${PV}.tar.gz \ file://libgcrypt-fix-building-error-with-O2-in-sysroot-path.patch \ file://fix-ICE-failure-on-mips-with-option-O-and-g.patch \ file://fix-undefined-reference-to-pthread.patch \ + file://CVE-2017-9526.patch \ " BINCONFIG = "${bindir}/libgcrypt-config" -- 2.7.4 -- _______________________________________________ Openembedded-core mailing list Openembedded-core@lists.openembedded.org http://lists.openembedded.org/mailman/listinfo/openembedded-core
