[OE-core] [PATCH][morty 1/2] libgcrypt: fix CVE-2017-9526

[akuster808]

On 07/18/2017 03:07 PM, Ross Burton wrote:
> 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.

is this version 2 or resend?

- armin
> Signed-off-by: Ross Burton <ross.burton at intel.com>
> ---
>   ...-Store-EdDSA-session-key-in-secure-memory.patch | 39 ++++++++++++++++++++++
>   meta/recipes-support/libgcrypt/libgcrypt.inc       |  1 +
>   2 files changed, 40 insertions(+)
>   create mode 100644 meta/recipes-support/libgcrypt/files/0001-ecc-Store-EdDSA-session-key-in-secure-memory.patch
>
> diff --git a/meta/recipes-support/libgcrypt/files/0001-ecc-Store-EdDSA-session-key-in-secure-memory.patch b/meta/recipes-support/libgcrypt/files/0001-ecc-Store-EdDSA-session-key-in-secure-memory.patch
> new file mode 100644
> index 00000000000..f6c4ca76f33
> --- /dev/null
> +++ b/meta/recipes-support/libgcrypt/files/0001-ecc-Store-EdDSA-session-key-in-secure-memory.patch
> @@ -0,0 +1,39 @@
> +CVE: CVE-2017-9526
> +Upstream-Status: Backport
> +Signed-off-by: Ross Burton <ross.burton at intel.com>
> +
> +From b3cab278eb9c2ceda79f980bc26460d97f260041 Mon Sep 17 00:00:00 2001
> +From: Jo Van Bulck <jo.vanbulck at 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 at 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 f91f8489..813e030d 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;
> +--
> +2.11.0
> +
> diff --git a/meta/recipes-support/libgcrypt/libgcrypt.inc b/meta/recipes-support/libgcrypt/libgcrypt.inc
> index 15805cd4365..7c4c0e83b53 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://0001-ecc-Store-EdDSA-session-key-in-secure-memory.patch \
>   "
>   
>   BINCONFIG = "${bindir}/libgcrypt-config"