Apply nettle CVE patches to el6 build

Patch taken directly from f22 nettle package
diff --git a/contrib/packages/rpm/el6/SOURCES/nettle-2.7.1-ecc-cve.patch b/contrib/packages/rpm/el6/SOURCES/nettle-2.7.1-ecc-cve.patch
new file mode 100644
index 0000000..130f2fc
--- /dev/null
+++ b/contrib/packages/rpm/el6/SOURCES/nettle-2.7.1-ecc-cve.patch
@@ -0,0 +1,275 @@
+diff --git a/ecc-256.c b/ecc-256.c
+index 571cf73..07841b1 100644
+--- a/ecc-256.c
++++ b/ecc-256.c
+@@ -108,7 +108,10 @@ ecc_256_modp (const struct ecc_curve *ecc, mp_limb_t *rp)
+       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, ecc->p, 2);
++      u0 += cy;
++      u1 += (u0 < cy);
+       u1 -= (-t) & 0xffffffff;
+     }
+   rp[2] = u0;
+@@ -195,7 +198,7 @@ ecc_256_modq (const struct ecc_curve *ecc, mp_limb_t *rp)
+ 
+       /* 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;
+diff --git a/x86_64/ecc-384-modp.asm b/x86_64/ecc-384-modp.asm
+index 698838f..31b739e 100644
+--- a/x86_64/ecc-384-modp.asm
++++ b/x86_64/ecc-384-modp.asm
+@@ -20,7 +20,7 @@ C MA 02111-1301, USA.
+ 	.file "ecc-384-modp.asm"
+ 
+ define(<RP>, <%rsi>)
+-define(<D4>, <%rax>)
++define(<D5>, <%rax>)
+ define(<T0>, <%rbx>)
+ define(<T1>, <%rcx>)
+ define(<T2>, <%rdx>)
+@@ -35,8 +35,8 @@ define(<H4>, <%r13>)
+ define(<H5>, <%r14>)
+ define(<C2>, <%r15>)
+ define(<C0>, H5)	C Overlap
+-define(<D0>, RP)	C Overlap
+-define(<TMP>, H4)	C Overlap
++define(<TMP>, RP)	C Overlap
++
+ 
+ PROLOGUE(nettle_ecc_384_modp)
+ 	W64_ENTRY(2, 0)
+@@ -48,34 +48,38 @@ PROLOGUE(nettle_ecc_384_modp)
+ 	push	%r14
+ 	push	%r15
+ 
+-	C First get top 2 limbs, which need folding twice
++	C First get top 2 limbs, which need folding twice.
++	C B^10 = B^6 + B^4 + 2^32 (B-1)B^4.
++	C We handle the terms as follow:
+ 	C
+-	C   H5 H4
+-	C     -H5
+-	C  ------
+-	C   H0 D4
++	C B^6: Folded immediatly.
+ 	C
+-	C Then shift right, (H1,H0,D4)  <--  (H0,D4) << 32
+-	C and add
++	C B^4: Delayed, added in in the next folding.
+ 	C
+-	C     H5 H4
+-	C     H1 H0
+-	C ----------
+-	C  C2 H1 H0
+-
+-	mov	80(RP), D4
+-	mov	88(RP), H0
+-	mov	D4, H4
+-	mov	H0, H5
+-	sub	H0, D4
+-	sbb	$0, H0
+-
+-	mov	D4, T2
+-	mov	H0, H1
+-	shl	$32, H0
+-	shr	$32, T2
++	C 2^32(B-1) B^4: Low half limb delayed until the next
++	C folding. Top 1.5 limbs subtracted and shifter now, resulting
++	C in 2.5 limbs. The low limb saved in D5, high 1.5 limbs added
++	C in.
++
++	mov	80(RP), H4
++	mov	88(RP), H5
++	C Shift right 32 bits, into H1, H0
++	mov	H4, H0
++	mov	H5, H1
++	mov	H5, D5
+ 	shr	$32, H1
+-	or	T2, H0
++	shl	$32, D5
++	shr	$32, H0
++	or	D5, H0
++
++	C	H1 H0
++	C       -  H1 H0
++	C       --------
++	C       H1 H0 D5
++	mov	H0, D5
++	neg	D5
++	sbb	H1, H0
++	sbb	$0, H1
+ 
+ 	xor	C2, C2
+ 	add	H4, H0
+@@ -114,118 +118,95 @@ PROLOGUE(nettle_ecc_384_modp)
+ 	adc	H3, T5
+ 	adc	$0, C0
+ 
+-	C   H3 H2 H1 H0  0
+-	C - H4 H3 H2 H1 H0
+-	C  ---------------
+-	C   H3 H2 H1 H0 D0
+-
+-	mov	XREG(D4), XREG(D4)
+-	mov	H0, D0
+-	neg	D0
+-	sbb	H1, H0
+-	sbb	H2, H1
+-	sbb	H3, H2
+-	sbb	H4, H3
+-	sbb	$0, D4
+-
+-	C Shift right. High bits are sign, to be added to C0.
+-	mov	D4, TMP
+-	sar	$32, TMP
+-	shl	$32, D4
+-	add	TMP, C0
+-
++	C Shift left, including low half of H4
+ 	mov	H3, TMP
++	shl	$32, H4
+ 	shr	$32, TMP
+-	shl	$32, H3
+-	or	TMP, D4
++	or	TMP, H4
+ 
+ 	mov	H2, TMP
++	shl	$32, H3
+ 	shr	$32, TMP
+-	shl	$32, H2
+ 	or	TMP, H3
+ 
+ 	mov	H1, TMP
++	shl	$32, H2
+ 	shr	$32, TMP
+-	shl	$32, H1
+ 	or	TMP, H2
+ 
+ 	mov	H0, TMP
++	shl	$32, H1
+ 	shr	$32, TMP
+-	shl	$32, H0
+ 	or	TMP, H1
+ 
+-	mov	D0, TMP
+-	shr	$32, TMP
+-	shl	$32, D0
+-	or	TMP, H0
++	shl	$32, H0
++
++	C   H4 H3 H2 H1 H0  0
++	C  -   H4 H3 H2 H1 H0
++	C  ---------------
++	C   H4 H3 H2 H1 H0 TMP
+ 
+-	add	D0, T0
++	mov	H0, TMP
++	neg	TMP
++	sbb	H1, H0
++	sbb	H2, H1
++	sbb	H3, H2
++	sbb	H4, H3
++	sbb	$0, H4
++
++	add	TMP, T0
+ 	adc	H0, T1
+ 	adc	H1, T2
+ 	adc	H2, T3
+ 	adc	H3, T4
+-	adc	D4, T5
++	adc	H4, T5
+ 	adc	$0, C0
+ 
+ 	C Remains to add in C2 and C0
+-	C                         C0  C0<<32  (-2^32+1)C0
+-	C    C2  C2<<32  (-2^32+1)C2
+-	C where C2 is always positive, while C0 may be -1.
++	C Set H1, H0 = (2^96 - 2^32 + 1) C0
+ 	mov	C0, H0
+ 	mov	C0, H1
+-	mov	C0, H2
+-	sar	$63, C0		C Get sign
+ 	shl	$32, H1
+-	sub	H1, H0		C Gives borrow iff C0 > 0
++	sub	H1, H0
+ 	sbb	$0, H1
+-	add	C0, H2
+ 
++	C Set H3, H2 = (2^96 - 2^32 + 1) C2
++	mov	C2, H2
++	mov	C2, H3
++	shl	$32, H3
++	sub	H3, H2
++	sbb	$0, H3
++	add	C0, H2		C No carry. Could use lea trick
++
++	xor	C0, C0
+ 	add	H0, T0
+ 	adc	H1, T1
+-	adc	$0, H2
+-	adc	$0, C0
+-
+-	C Set (H1 H0)  <-- C2 << 96 - C2 << 32 + 1
+-	mov	C2, H0
+-	mov	C2, H1
+-	shl	$32, H1
+-	sub	H1, H0
+-	sbb	$0, H1
+-
+-	add	H2, H0
+-	adc	C0, H1
+-	adc	C2, C0
+-	mov	C0, H2
+-	sar	$63, C0
+-	add	H0, T2
+-	adc	H1, T3
+-	adc	H2, T4
+-	adc	C0, T5
+-	sbb	C0, C0
++	adc	H2, T2
++	adc	H3, T3
++	adc	C2, T4
++	adc	D5, T5		C Value delayed from initial folding
++	adc	$0, C0		C Use sbb and switch sign?
+ 
+ 	C Final unlikely carry
+ 	mov	C0, H0
+ 	mov	C0, H1
+-	mov	C0, H2
+-	sar	$63, C0
+ 	shl	$32, H1
+ 	sub	H1, H0
+ 	sbb	$0, H1
+-	add	C0, H2
+ 
+ 	pop	RP
+ 
+-	sub	H0, T0
++	add	H0, T0
+ 	mov	T0, (RP)
+-	sbb	H1, T1
++	adc	H1, T1
+ 	mov	T1, 8(RP)
+-	sbb	H2, T2
++	adc	C0, T2
+ 	mov	T2, 16(RP)
+-	sbb	C0, T3
++	adc	$0, T3
+ 	mov	T3, 24(RP)
+-	sbb	C0, T4
++	adc	$0, T4
+ 	mov	T4, 32(RP)
+-	sbb	C0, T5
++	adc	$0, T5
+ 	mov	T5, 40(RP)
+ 
+ 	pop	%r15
diff --git a/contrib/packages/rpm/el6/SPECS/tigervnc.spec b/contrib/packages/rpm/el6/SPECS/tigervnc.spec
index 67bd82d..16d1ba5 100644
--- a/contrib/packages/rpm/el6/SPECS/tigervnc.spec
+++ b/contrib/packages/rpm/el6/SPECS/tigervnc.spec
@@ -10,7 +10,7 @@
 
 Name: tigervnc
 Version: @VERSION@
-Release: 3%{?snap:.%{snap}}%{?dist}
+Release: 4%{?snap:.%{snap}}%{?dist}
 Summary: A TigerVNC remote display system
 
 Group: User Interface/Desktops
@@ -60,6 +60,7 @@
 Obsoletes: tightvnc < 1.5.0-0.15.20090204svn3586
 
 Patch16: tigervnc-xorg-manpages.patch
+Patch17: nettle-2.7.1-ecc-cve.patch
 
 %description
 Virtual Network Computing (VNC) is a remote display system which
@@ -165,6 +166,9 @@
 tar xjf %SOURCE14
 tar xzf %SOURCE15
 tar xzf %SOURCE16
+pushd nettle-*
+%patch17 -p1 -b .ecc-cve
+popd
 xzcat %SOURCE17 | tar xf -
 %endif
 
@@ -456,6 +460,9 @@
 %endif
 
 %changelog
+* Sat Apr 02 2016 Brian P. Hinz <bphinz@users.sourceforge.net> 1.6.80-4
+- Fixed CVE-2015-8803 CVE-2015-8804 CVE-2015-8805 secp256r1 and secp384r1 bugs
+
 * Fri Dec 11 2015 Brian P. Hinz <bphinz@users.sourceforge.net> 1.6.80-3
 - Configure with --host and --build to avoid build host-specific compiler opts