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-rw-r--r--meta/recipes-support/libgcrypt/files/0001-dsa-ecdsa-Fix-use-of-nonce-use-larger-one.patch128
1 files changed, 128 insertions, 0 deletions
diff --git a/meta/recipes-support/libgcrypt/files/0001-dsa-ecdsa-Fix-use-of-nonce-use-larger-one.patch b/meta/recipes-support/libgcrypt/files/0001-dsa-ecdsa-Fix-use-of-nonce-use-larger-one.patch
new file mode 100644
index 0000000000..211e041303
--- /dev/null
+++ b/meta/recipes-support/libgcrypt/files/0001-dsa-ecdsa-Fix-use-of-nonce-use-larger-one.patch
@@ -0,0 +1,128 @@
+From db4e9976cc31b314aafad6626b2894e86ee44d60 Mon Sep 17 00:00:00 2001
+From: NIIBE Yutaka <gniibe@fsij.org>
+Date: Thu, 8 Aug 2019 17:42:02 +0900
+Subject: [PATCH] dsa,ecdsa: Fix use of nonce, use larger one.
+
+Upstream-Status: Backport [https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=db4e9976cc3]
+CVE: CVE-2019-13627
+Signed-off-by: Trevor Gamblin <trevor.gamblin@windriver.com>
+
+* cipher/dsa-common.c (_gcry_dsa_modify_k): New.
+* cipher/pubkey-internal.h (_gcry_dsa_modify_k): New.
+* cipher/dsa.c (sign): Use _gcry_dsa_modify_k.
+* cipher/ecc-ecdsa.c (_gcry_ecc_ecdsa_sign): Likewise.
+* cipher/ecc-gost.c (_gcry_ecc_gost_sign): Likewise.
+
+--
+
+Cherry-picked master commit of:
+ 7c2943309d14407b51c8166c4dcecb56a3628567
+
+CVE-id: CVE-2019-13627
+GnuPG-bug-id: 4626
+Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
+---
+ cipher/dsa-common.c | 24 ++++++++++++++++++++++++
+ cipher/dsa.c | 2 ++
+ cipher/ecc-ecdsa.c | 10 +---------
+ cipher/ecc-gost.c | 2 ++
+ cipher/pubkey-internal.h | 1 +
+ 5 files changed, 30 insertions(+), 9 deletions(-)
+
+diff --git a/cipher/dsa-common.c b/cipher/dsa-common.c
+index 8c0a6843..fe49248d 100644
+--- a/cipher/dsa-common.c
++++ b/cipher/dsa-common.c
+@@ -29,6 +29,30 @@
+ #include "pubkey-internal.h"
+
+
++/*
++ * Modify K, so that computation time difference can be small,
++ * by making K large enough.
++ *
++ * Originally, (EC)DSA computation requires k where 0 < k < q. Here,
++ * we add q (the order), to keep k in a range: q < k < 2*q (or,
++ * addming more q, to keep k in a range: 2*q < k < 3*q), so that
++ * timing difference of the EC multiply (or exponentiation) operation
++ * can be small. The result of (EC)DSA computation is same.
++ */
++void
++_gcry_dsa_modify_k (gcry_mpi_t k, gcry_mpi_t q, int qbits)
++{
++ gcry_mpi_t k1 = mpi_new (qbits+2);
++
++ mpi_resize (k, (qbits+2+BITS_PER_MPI_LIMB-1) / BITS_PER_MPI_LIMB);
++ k->nlimbs = k->alloced;
++ mpi_add (k, k, q);
++ mpi_add (k1, k, q);
++ mpi_set_cond (k, k1, !mpi_test_bit (k, qbits));
++
++ mpi_free (k1);
++}
++
+ /*
+ * Generate a random secret exponent K less than Q.
+ * Note that ECDSA uses this code also to generate D.
+diff --git a/cipher/dsa.c b/cipher/dsa.c
+index 22d8d782..24a53528 100644
+--- a/cipher/dsa.c
++++ b/cipher/dsa.c
+@@ -635,6 +635,8 @@ sign (gcry_mpi_t r, gcry_mpi_t s, gcry_mpi_t input, DSA_secret_key *skey,
+ k = _gcry_dsa_gen_k (skey->q, GCRY_STRONG_RANDOM);
+ }
+
++ _gcry_dsa_modify_k (k, skey->q, qbits);
++
+ /* r = (a^k mod p) mod q */
+ mpi_powm( r, skey->g, k, skey->p );
+ mpi_fdiv_r( r, r, skey->q );
+diff --git a/cipher/ecc-ecdsa.c b/cipher/ecc-ecdsa.c
+index 84a1cf84..97966c3a 100644
+--- a/cipher/ecc-ecdsa.c
++++ b/cipher/ecc-ecdsa.c
+@@ -114,15 +114,7 @@ _gcry_ecc_ecdsa_sign (gcry_mpi_t input, ECC_secret_key *skey,
+ else
+ k = _gcry_dsa_gen_k (skey->E.n, GCRY_STRONG_RANDOM);
+
+- /* Originally, ECDSA computation requires k where 0 < k < n.
+- * Here, we add n (the order of curve), to keep k in a
+- * range: n < k < 2*n, or, addming more n, keep k in a range:
+- * 2*n < k < 3*n, so that timing difference of the EC
+- * multiply operation can be small. The result is same.
+- */
+- mpi_add (k, k, skey->E.n);
+- if (!mpi_test_bit (k, qbits))
+- mpi_add (k, k, skey->E.n);
++ _gcry_dsa_modify_k (k, skey->E.n, qbits);
+
+ _gcry_mpi_ec_mul_point (&I, k, &skey->E.G, ctx);
+ if (_gcry_mpi_ec_get_affine (x, NULL, &I, ctx))
+diff --git a/cipher/ecc-gost.c b/cipher/ecc-gost.c
+index a34fa084..0362a6c7 100644
+--- a/cipher/ecc-gost.c
++++ b/cipher/ecc-gost.c
+@@ -94,6 +94,8 @@ _gcry_ecc_gost_sign (gcry_mpi_t input, ECC_secret_key *skey,
+ mpi_free (k);
+ k = _gcry_dsa_gen_k (skey->E.n, GCRY_STRONG_RANDOM);
+
++ _gcry_dsa_modify_k (k, skey->E.n, qbits);
++
+ _gcry_mpi_ec_mul_point (&I, k, &skey->E.G, ctx);
+ if (_gcry_mpi_ec_get_affine (x, NULL, &I, ctx))
+ {
+diff --git a/cipher/pubkey-internal.h b/cipher/pubkey-internal.h
+index b8167c77..d31e26f3 100644
+--- a/cipher/pubkey-internal.h
++++ b/cipher/pubkey-internal.h
+@@ -84,6 +84,7 @@ _gcry_rsa_pss_verify (gcry_mpi_t value, gcry_mpi_t encoded,
+
+
+ /*-- dsa-common.c --*/
++void _gcry_dsa_modify_k (gcry_mpi_t k, gcry_mpi_t q, int qbits);
+ gcry_mpi_t _gcry_dsa_gen_k (gcry_mpi_t q, int security_level);
+ gpg_err_code_t _gcry_dsa_gen_rfc6979_k (gcry_mpi_t *r_k,
+ gcry_mpi_t dsa_q, gcry_mpi_t dsa_x,
+--
+2.23.0
+