--- /dev/null
+From 9010d1576e278a4274ad3f4aa15776c28f6ba965 Mon Sep 17 00:00:00 2001
+From: NIIBE Yutaka <gniibe@fsij.org>
+Date: Wed, 13 Jun 2018 15:28:58 +0900
+Subject: [PATCH] ecc: Add blinding for ECDSA.
+
+* cipher/ecc-ecdsa.c (_gcry_ecc_ecdsa_sign): Blind secret D with
+randomized nonce B.
+
+--
+
+Reported-by: Keegan Ryan <Keegan.Ryan@nccgroup.trust>
+CVE-id: CVE-2018-0495
+
+Upstream-Status: Backport [http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=9010d1576e278a4274ad3f4aa15776c28f6ba965]
+
+Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
+Signed-off-by: Jagadeesh Krishnanjanappa <jkrishnanjanappa@mvista.com>
+---
+ cipher/ecc-ecdsa.c | 20 ++++++++++++++++++--
+ 1 file changed, 18 insertions(+), 2 deletions(-)
+
+diff --git a/cipher/ecc-ecdsa.c b/cipher/ecc-ecdsa.c
+index 1484830b..140e8c09 100644
+--- a/cipher/ecc-ecdsa.c
++++ b/cipher/ecc-ecdsa.c
+@@ -50,6 +50,8 @@ _gcry_ecc_ecdsa_sign (gcry_mpi_t input, ECC_secret_key *skey,
+ const void *abuf;
+ unsigned int abits, qbits;
+ mpi_ec_t ctx;
++ gcry_mpi_t b; /* Random number needed for blinding. */
++ gcry_mpi_t bi; /* multiplicative inverse of B. */
+
+ if (DBG_CIPHER)
+ log_mpidump ("ecdsa sign hash ", input );
+@@ -61,6 +63,15 @@ _gcry_ecc_ecdsa_sign (gcry_mpi_t input, ECC_secret_key *skey,
+ if (rc)
+ return rc;
+
++ b = mpi_snew (qbits);
++ bi = mpi_snew (qbits);
++ do
++ {
++ _gcry_mpi_randomize (b, qbits, GCRY_WEAK_RANDOM);
++ mpi_mod (b, b, skey->E.n);
++ }
++ while (!mpi_invm (bi, b, skey->E.n));
++
+ k = NULL;
+ dr = mpi_alloc (0);
+ sum = mpi_alloc (0);
+@@ -115,8 +126,11 @@ _gcry_ecc_ecdsa_sign (gcry_mpi_t input, ECC_secret_key *skey,
+ }
+ while (!mpi_cmp_ui (r, 0));
+
+- mpi_mulm (dr, skey->d, r, skey->E.n); /* dr = d*r mod n */
+- mpi_addm (sum, hash, dr, skey->E.n); /* sum = hash + (d*r) mod n */
++ mpi_mulm (dr, b, skey->d, skey->E.n);
++ mpi_mulm (dr, dr, r, skey->E.n); /* dr = d*r mod n (blinded with b) */
++ mpi_mulm (sum, b, hash, skey->E.n);
++ mpi_addm (sum, sum, dr, skey->E.n); /* sum = hash + (d*r) mod n (blinded with b) */
++ mpi_mulm (sum, bi, sum, skey->E.n); /* undo blinding by b^-1 */
+ mpi_invm (k_1, k, skey->E.n); /* k_1 = k^(-1) mod n */
+ mpi_mulm (s, k_1, sum, skey->E.n); /* s = k^(-1)*(hash+(d*r)) mod n */
+ }
+@@ -129,6 +143,8 @@ _gcry_ecc_ecdsa_sign (gcry_mpi_t input, ECC_secret_key *skey,
+ }
+
+ leave:
++ mpi_free (b);
++ mpi_free (bi);
+ _gcry_mpi_ec_free (ctx);
+ point_free (&I);
+ mpi_free (x);
+--
+2.13.3
+
