nettle: Security fix CVE-2015-8803 and CVE-2015-8805

(From OE-Core master rev: f62eb452244c3124cc88ef01c14116dac43f377a)

hand applied changes for ecc-256.c

(From OE-Core rev: cb03397ac97bfa99df6b72c80e1e03214e059e6e)

Signed-off-by: Armin Kuster <akuster@mvista.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster@mvista.com>
Signed-off-by: Joshua Lock <joshua.g.lock@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 75 insertions, 0 deletions

diff --git a/meta/recipes-support/nettle/nettle-2.7.1/CVE-2015-8803_8805.patch b/meta/recipes-support/nettle/nettle-2.7.1/CVE-2015-8803_8805.patch
new file mode 100644
index 0000000000..1c4b9a98f2
--- /dev/null
+++ b/meta/recipes-support/nettle/nettle-2.7.1/CVE-2015-8803_8805.patch
@@ -0,0 +1,71 @@
+Upstream-Status: Backport
+https://git.lysator.liu.se/nettle/nettle/commit/c71d2c9d20eeebb985e3872e4550137209e3ce4d
+
+CVE: CVE-2015-8803
+CVE: CVE-2015-8805
+
+Same fix for both.
+
+Signed-off-by: Armin Kuster <akuster@mvista.com>
+
+Index: nettle-2.7.1/ecc-256.c
+===================================================================
+--- nettle-2.7.1.orig/ecc-256.c
++++ nettle-2.7.1/ecc-256.c
+@@ -96,9 +96,19 @@ ecc_256_modp (const struct ecc_curve *ec
+       q2 += t + (q1 < t);
+ 
+       assert (q2 < 2);
++      /*
++   n-1 n-2 n-3 n-4
++        +---+---+---+---+
++        | u1| u0| u low |
++        +---+---+---+---+
++          - | q1(2^96-1)|
++            +-------+---+
++            |q2(2^.)|
++            +-------+
+ 
+-      /* We multiply by two low limbs of p, 2^96 - 1, so we could use
+-        shifts rather than mul. */
++   We multiply by two low limbs of p, 2^96 - 1, so we could use
++   shifts rather than mul.
++      */
+       t = mpn_submul_1 (rp + n - 4, ecc->p, 2, q1);
+       t += cnd_sub_n (q2, rp + n - 3, ecc->p, 1);
+       t += (-q2) & 0xffffffff;
+@@ -108,7 +118,10 @@ ecc_256_modp (const struct ecc_curve *ec
+       u0 -= t;
+       t = (u1 < cy);
+       u1 -= cy;
+-      u1 += cnd_add_n (t, rp + n - 4, ecc->p, 3);
++
++      cy = cnd_add_n (t, rp + n - 4, p->m, 2);
++      u0 += cy;
++      u1 += (u0 < cy);
+       u1 -= (-t) & 0xffffffff;
+     }
+   rp[2] = u0;
+@@ -195,7 +208,7 @@ ecc_256_modq (const struct ecc_curve *ec
+ 
+       /* Conditional add of p */
+       u1 += t;
+-      u2 += (t<<32) + (u0 < t);
++      u2 += (t<<32) + (u1 < t);
+ 
+       t = cnd_add_n (t, rp + n - 4, ecc->q, 2);
+       u1 += t;
+Index: nettle-2.7.1/ChangeLog
+===================================================================
+--- nettle-2.7.1.orig/ChangeLog
++++ nettle-2.7.1/ChangeLog
+@@ -1,3 +1,9 @@
++2015-12-10  Niels Möller  <nisse@lysator.liu.se>
++
++   * ecc-256.c (ecc_256_modp): Fixed carry propagation bug. Problem
++   reported by Hanno Böck.
++   (ecc_256_modq): Fixed another carry propagation bug.
++
+ 2013-05-28  Niels Möller  <nisse@lysator.liu.se>
+ 
+        * Released nettle-2.7.1.
diff --git a/meta/recipes-support/nettle/nettle_2.7.1.bb b/meta/recipes-support/nettle/nettle_2.7.1.bb
index f53afcc5d4..05d262346b 100644
--- a/meta/recipes-support/nettle/nettle_2.7.1.bb
+++ b/meta/recipes-support/nettle/nettle_2.7.1.bb
@@ -10,6 +10,10 @@ DEPENDS += "gmp"
 
 SRC_URI = "http://www.lysator.liu.se/~nisse/archive/${BP}.tar.gz"
 
+SRC_URI += "\
+            file://CVE-2015-8803_8805.patch \
+            "
+
 SRC_URI[md5sum] = "003d5147911317931dd453520eb234a5"
 SRC_URI[sha256sum] = "bc71ebd43435537d767799e414fce88e521b7278d48c860651216e1fc6555b40"