Merge tag 'master-2014-12-08' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next

John W. Linville says:

====================
pull request: wireless-next 2014-12-08

Please pull this last batch of pending wireless updates for the 3.19 tree...

For the wireless bits, Johannes says:

"This time I have Felix's no-status rate control work, which will allow
drivers to work better with rate control even if they don't have perfect
status reporting. In addition to this, a small hwsim fix from Patrik,
one of the regulatory patches from Arik, and a number of cleanups and
fixes I did myself.

Of note is a patch where I disable CFG80211_WEXT so that compatibility
is no longer selectable - this is intended as a wake-up call for anyone
who's still using it, and is still easily worked around (it's a one-line
patch) before we fully remove the code as well in the future."

For the Bluetooth bits, Johan says:

"Here's one more bluetooth-next pull request for 3.19:

 - Minor cleanups for ieee802154 & mac802154
 - Fix for the kernel warning with !TASK_RUNNING reported by Kirill A.
   Shutemov
 - Support for another ath3k device
 - Fix for tracking link key based security level
 - Device tree bindings for btmrvl + a state update fix
 - Fix for wrong ACL flags on LE links"

And...

"In addition to the previous one this contains two more cleanups to
mac802154 as well as support for some new HCI features from the
Bluetooth 4.2 specification.

From the original request:

'Here's what should be the last bluetooth-next pull request for 3.19.
It's rather large but the majority of it is the Low Energy Secure
Connections feature that's part of the Bluetooth 4.2 specification. The
specification went public only this week so we couldn't publish the
corresponding code before that. The code itself can nevertheless be
considered fairly mature as it's been in development for over 6 months
and gone through several interoperability test events.

Besides LE SC the pull request contains an important fix for command
complete events for mgmt sockets which also fixes some leaks of hci_conn
objects when powering off or unplugging Bluetooth adapters.

A smaller feature that's part of the pull request is service discovery
support. This is like normal device discovery except that devices not
matching specific UUIDs or strong enough RSSI are filtered out.

Other changes that the pull request contains are firmware dump support
to the btmrvl driver, firmware download support for Broadcom BCM20702A0
variants, as well as some coding style cleanups in 6lowpan &
ieee802154/mac802154 code.'"

For the NFC bits, Samuel says:

"With this one we get:

- NFC digital improvements for DEP support: Chaining, NACK and ATN
  support added.

- NCI improvements: Support for p2p target, SE IO operand addition,
  SE operands extensions to support proprietary implementations, and
  a few fixes.

- NFC HCI improvements: OPEN_PIPE and NOTIFY_ALL_CLEARED support,
  and SE IO operand addition.

- A bunch of minor improvements and fixes for STMicro st21nfcb and
  st21nfca"

For the iwlwifi bits, Emmanuel says:

"Major works are CSA and TDLS. On top of that I have a new
firmware API for scan and a few rate control improvements.
Johannes find a few tricks to improve our CPU utilization
and adds support for a new spin of 7265 called 7265D.
Along with this a few random things that don't stand out."

And...

"I deprecate here -8.ucode since -9 has been published long ago.
Along with that I have a new activity, we have now better
a infrastructure for firmware debugging. This will allow to
have configurable probes insides the firmware.
Luca continues his work on NetDetect, this feature is now
complete. All the rest is minor fixes here and there."

For the Atheros bits, Kalle says:

"Only ath10k changes this time and no major changes. Most visible are:

o new debugfs interface for runtime firmware debugging (Yanbo)

o fix shared WEP (Sujith)

o don't rebuild whenever kernel version changes (Johannes)

o lots of refactoring to make it easier to add new hw support (Michal)

There's also smaller fixes and improvements with no point of listing
here."

In addition, there are a few last minute updates to ath5k,
ath9k, brcmfmac, brcmsmac, mwifiex, rt2x00, rtlwifi, and wil6210.
Also included is a pull of the wireless tree to pick-up the fixes
originally included in "pull request: wireless 2014-12-03"...

Please let me know if there are problems!
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 816 insertions, 0 deletions

diff --git a/net/bluetooth/ecc.c b/net/bluetooth/ecc.c
new file mode 100644
index 000000000000..e1709f8467ac
--- /dev/null
+++ b/net/bluetooth/ecc.c
@@ -0,0 +1,816 @@
+/*
+ * Copyright (c) 2013, Kenneth MacKay
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *  * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/random.h>
+
+#include "ecc.h"
+
+/* 256-bit curve */
+#define ECC_BYTES 32
+
+#define MAX_TRIES 16
+
+/* Number of u64's needed */
+#define NUM_ECC_DIGITS (ECC_BYTES / 8)
+
+struct ecc_point {
+	u64 x[NUM_ECC_DIGITS];
+	u64 y[NUM_ECC_DIGITS];
+};
+
+typedef struct {
+	u64 m_low;
+	u64 m_high;
+} uint128_t;
+
+#define CURVE_P_32 {	0xFFFFFFFFFFFFFFFFull, 0x00000000FFFFFFFFull, \
+			0x0000000000000000ull, 0xFFFFFFFF00000001ull }
+
+#define CURVE_G_32 { \
+		{	0xF4A13945D898C296ull, 0x77037D812DEB33A0ull,	\
+			0xF8BCE6E563A440F2ull, 0x6B17D1F2E12C4247ull }, \
+		{	0xCBB6406837BF51F5ull, 0x2BCE33576B315ECEull,	\
+			0x8EE7EB4A7C0F9E16ull, 0x4FE342E2FE1A7F9Bull }	\
+}
+
+#define CURVE_N_32 {	0xF3B9CAC2FC632551ull, 0xBCE6FAADA7179E84ull,	\
+			0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFF00000000ull }
+
+static u64 curve_p[NUM_ECC_DIGITS] = CURVE_P_32;
+static struct ecc_point curve_g = CURVE_G_32;
+static u64 curve_n[NUM_ECC_DIGITS] = CURVE_N_32;
+
+static void vli_clear(u64 *vli)
+{
+	int i;
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++)
+		vli[i] = 0;
+}
+
+/* Returns true if vli == 0, false otherwise. */
+static bool vli_is_zero(const u64 *vli)
+{
+	int i;
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++) {
+		if (vli[i])
+			return false;
+	}
+
+	return true;
+}
+
+/* Returns nonzero if bit bit of vli is set. */
+static u64 vli_test_bit(const u64 *vli, unsigned int bit)
+{
+	return (vli[bit / 64] & ((u64) 1 << (bit % 64)));
+}
+
+/* Counts the number of 64-bit "digits" in vli. */
+static unsigned int vli_num_digits(const u64 *vli)
+{
+	int i;
+
+	/* Search from the end until we find a non-zero digit.
+	 * We do it in reverse because we expect that most digits will
+	 * be nonzero.
+	 */
+	for (i = NUM_ECC_DIGITS - 1; i >= 0 && vli[i] == 0; i--);
+
+	return (i + 1);
+}
+
+/* Counts the number of bits required for vli. */
+static unsigned int vli_num_bits(const u64 *vli)
+{
+	unsigned int i, num_digits;
+	u64 digit;
+
+	num_digits = vli_num_digits(vli);
+	if (num_digits == 0)
+		return 0;
+
+	digit = vli[num_digits - 1];
+	for (i = 0; digit; i++)
+		digit >>= 1;
+
+	return ((num_digits - 1) * 64 + i);
+}
+
+/* Sets dest = src. */
+static void vli_set(u64 *dest, const u64 *src)
+{
+	int i;
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++)
+		dest[i] = src[i];
+}
+
+/* Returns sign of left - right. */
+static int vli_cmp(const u64 *left, const u64 *right)
+{
+    int i;
+
+    for (i = NUM_ECC_DIGITS - 1; i >= 0; i--) {
+	    if (left[i] > right[i])
+		    return 1;
+	    else if (left[i] < right[i])
+		    return -1;
+    }
+
+    return 0;
+}
+
+/* Computes result = in << c, returning carry. Can modify in place
+ * (if result == in). 0 < shift < 64.
+ */
+static u64 vli_lshift(u64 *result, const u64 *in,
+			   unsigned int shift)
+{
+	u64 carry = 0;
+	int i;
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++) {
+		u64 temp = in[i];
+
+		result[i] = (temp << shift) | carry;
+		carry = temp >> (64 - shift);
+	}
+
+	return carry;
+}
+
+/* Computes vli = vli >> 1. */
+static void vli_rshift1(u64 *vli)
+{
+	u64 *end = vli;
+	u64 carry = 0;
+
+	vli += NUM_ECC_DIGITS;
+
+	while (vli-- > end) {
+		u64 temp = *vli;
+		*vli = (temp >> 1) | carry;
+		carry = temp << 63;
+	}
+}
+
+/* Computes result = left + right, returning carry. Can modify in place. */
+static u64 vli_add(u64 *result, const u64 *left,
+			const u64 *right)
+{
+	u64 carry = 0;
+	int i;
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++) {
+		u64 sum;
+
+		sum = left[i] + right[i] + carry;
+		if (sum != left[i])
+			carry = (sum < left[i]);
+
+		result[i] = sum;
+	}
+
+	return carry;
+}
+
+/* Computes result = left - right, returning borrow. Can modify in place. */
+static u64 vli_sub(u64 *result, const u64 *left, const u64 *right)
+{
+	u64 borrow = 0;
+	int i;
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++) {
+		u64 diff;
+
+		diff = left[i] - right[i] - borrow;
+		if (diff != left[i])
+			borrow = (diff > left[i]);
+
+		result[i] = diff;
+	}
+
+	return borrow;
+}
+
+static uint128_t mul_64_64(u64 left, u64 right)
+{
+	u64 a0 = left & 0xffffffffull;
+	u64 a1 = left >> 32;
+	u64 b0 = right & 0xffffffffull;
+	u64 b1 = right >> 32;
+	u64 m0 = a0 * b0;
+	u64 m1 = a0 * b1;
+	u64 m2 = a1 * b0;
+	u64 m3 = a1 * b1;
+	uint128_t result;
+
+	m2 += (m0 >> 32);
+	m2 += m1;
+
+	/* Overflow */
+	if (m2 < m1)
+		m3 += 0x100000000ull;
+
+	result.m_low = (m0 & 0xffffffffull) | (m2 << 32);
+	result.m_high = m3 + (m2 >> 32);
+
+	return result;
+}
+
+static uint128_t add_128_128(uint128_t a, uint128_t b)
+{
+	uint128_t result;
+
+	result.m_low = a.m_low + b.m_low;
+	result.m_high = a.m_high + b.m_high + (result.m_low < a.m_low);
+
+	return result;
+}
+
+static void vli_mult(u64 *result, const u64 *left, const u64 *right)
+{
+	uint128_t r01 = { 0, 0 };
+	u64 r2 = 0;
+	unsigned int i, k;
+
+	/* Compute each digit of result in sequence, maintaining the
+	 * carries.
+	 */
+	for (k = 0; k < NUM_ECC_DIGITS * 2 - 1; k++) {
+		unsigned int min;
+
+		if (k < NUM_ECC_DIGITS)
+			min = 0;
+		else
+			min = (k + 1) - NUM_ECC_DIGITS;
+
+		for (i = min; i <= k && i < NUM_ECC_DIGITS; i++) {
+			uint128_t product;
+
+			product = mul_64_64(left[i], right[k - i]);
+
+			r01 = add_128_128(r01, product);
+			r2 += (r01.m_high < product.m_high);
+		}
+
+		result[k] = r01.m_low;
+		r01.m_low = r01.m_high;
+		r01.m_high = r2;
+		r2 = 0;
+	}
+
+	result[NUM_ECC_DIGITS * 2 - 1] = r01.m_low;
+}
+
+static void vli_square(u64 *result, const u64 *left)
+{
+	uint128_t r01 = { 0, 0 };
+	u64 r2 = 0;
+	int i, k;
+
+	for (k = 0; k < NUM_ECC_DIGITS * 2 - 1; k++) {
+		unsigned int min;
+
+		if (k < NUM_ECC_DIGITS)
+			min = 0;
+		else
+			min = (k + 1) - NUM_ECC_DIGITS;
+
+		for (i = min; i <= k && i <= k - i; i++) {
+			uint128_t product;
+
+			product = mul_64_64(left[i], left[k - i]);
+
+			if (i < k - i) {
+				r2 += product.m_high >> 63;
+				product.m_high = (product.m_high << 1) |
+						 (product.m_low >> 63);
+				product.m_low <<= 1;
+			}
+
+			r01 = add_128_128(r01, product);
+			r2 += (r01.m_high < product.m_high);
+		}
+
+		result[k] = r01.m_low;
+		r01.m_low = r01.m_high;
+		r01.m_high = r2;
+		r2 = 0;
+	}
+
+	result[NUM_ECC_DIGITS * 2 - 1] = r01.m_low;
+}
+
+/* Computes result = (left + right) % mod.
+ * Assumes that left < mod and right < mod, result != mod.
+ */
+static void vli_mod_add(u64 *result, const u64 *left, const u64 *right,
+			const u64 *mod)
+{
+	u64 carry;
+
+	carry = vli_add(result, left, right);
+
+	/* result > mod (result = mod + remainder), so subtract mod to
+	 * get remainder.
+	 */
+	if (carry || vli_cmp(result, mod) >= 0)
+		vli_sub(result, result, mod);
+}
+
+/* Computes result = (left - right) % mod.
+ * Assumes that left < mod and right < mod, result != mod.
+ */
+static void vli_mod_sub(u64 *result, const u64 *left, const u64 *right,
+			const u64 *mod)
+{
+	u64 borrow = vli_sub(result, left, right);
+
+	/* In this case, p_result == -diff == (max int) - diff.
+	 * Since -x % d == d - x, we can get the correct result from
+	 * result + mod (with overflow).
+	 */
+	if (borrow)
+		vli_add(result, result, mod);
+}
+
+/* Computes result = product % curve_p
+   from http://www.nsa.gov/ia/_files/nist-routines.pdf */
+static void vli_mmod_fast(u64 *result, const u64 *product)
+{
+	u64 tmp[NUM_ECC_DIGITS];
+	int carry;
+
+	/* t */
+	vli_set(result, product);
+
+	/* s1 */
+	tmp[0] = 0;
+	tmp[1] = product[5] & 0xffffffff00000000ull;
+	tmp[2] = product[6];
+	tmp[3] = product[7];
+	carry = vli_lshift(tmp, tmp, 1);
+	carry += vli_add(result, result, tmp);
+
+	/* s2 */
+	tmp[1] = product[6] << 32;
+	tmp[2] = (product[6] >> 32) | (product[7] << 32);
+	tmp[3] = product[7] >> 32;
+	carry += vli_lshift(tmp, tmp, 1);
+	carry += vli_add(result, result, tmp);
+
+	/* s3 */
+	tmp[0] = product[4];
+	tmp[1] = product[5] & 0xffffffff;
+	tmp[2] = 0;
+	tmp[3] = product[7];
+	carry += vli_add(result, result, tmp);
+
+	/* s4 */
+	tmp[0] = (product[4] >> 32) | (product[5] << 32);
+	tmp[1] = (product[5] >> 32) | (product[6] & 0xffffffff00000000ull);
+	tmp[2] = product[7];
+	tmp[3] = (product[6] >> 32) | (product[4] << 32);
+	carry += vli_add(result, result, tmp);
+
+	/* d1 */
+	tmp[0] = (product[5] >> 32) | (product[6] << 32);
+	tmp[1] = (product[6] >> 32);
+	tmp[2] = 0;
+	tmp[3] = (product[4] & 0xffffffff) | (product[5] << 32);
+	carry -= vli_sub(result, result, tmp);
+
+	/* d2 */
+	tmp[0] = product[6];
+	tmp[1] = product[7];
+	tmp[2] = 0;
+	tmp[3] = (product[4] >> 32) | (product[5] & 0xffffffff00000000ull);
+	carry -= vli_sub(result, result, tmp);
+
+	/* d3 */
+	tmp[0] = (product[6] >> 32) | (product[7] << 32);
+	tmp[1] = (product[7] >> 32) | (product[4] << 32);
+	tmp[2] = (product[4] >> 32) | (product[5] << 32);
+	tmp[3] = (product[6] << 32);
+	carry -= vli_sub(result, result, tmp);
+
+	/* d4 */
+	tmp[0] = product[7];
+	tmp[1] = product[4] & 0xffffffff00000000ull;
+	tmp[2] = product[5];
+	tmp[3] = product[6] & 0xffffffff00000000ull;
+	carry -= vli_sub(result, result, tmp);
+
+	if (carry < 0) {
+		do {
+			carry += vli_add(result, result, curve_p);
+		} while (carry < 0);
+	} else {
+		while (carry || vli_cmp(curve_p, result) != 1)
+			carry -= vli_sub(result, result, curve_p);
+	}
+}
+
+/* Computes result = (left * right) % curve_p. */
+static void vli_mod_mult_fast(u64 *result, const u64 *left, const u64 *right)
+{
+	u64 product[2 * NUM_ECC_DIGITS];
+
+	vli_mult(product, left, right);
+	vli_mmod_fast(result, product);
+}
+
+/* Computes result = left^2 % curve_p. */
+static void vli_mod_square_fast(u64 *result, const u64 *left)
+{
+	u64 product[2 * NUM_ECC_DIGITS];
+
+	vli_square(product, left);
+	vli_mmod_fast(result, product);
+}
+
+#define EVEN(vli) (!(vli[0] & 1))
+/* Computes result = (1 / p_input) % mod. All VLIs are the same size.
+ * See "From Euclid's GCD to Montgomery Multiplication to the Great Divide"
+ * https://labs.oracle.com/techrep/2001/smli_tr-2001-95.pdf
+ */
+static void vli_mod_inv(u64 *result, const u64 *input, const u64 *mod)
+{
+	u64 a[NUM_ECC_DIGITS], b[NUM_ECC_DIGITS];
+	u64 u[NUM_ECC_DIGITS], v[NUM_ECC_DIGITS];
+	u64 carry;
+	int cmp_result;
+
+	if (vli_is_zero(input)) {
+		vli_clear(result);
+		return;
+	}
+
+	vli_set(a, input);
+	vli_set(b, mod);
+	vli_clear(u);
+	u[0] = 1;
+	vli_clear(v);
+
+	while ((cmp_result = vli_cmp(a, b)) != 0) {
+		carry = 0;
+
+		if (EVEN(a)) {
+			vli_rshift1(a);
+
+			if (!EVEN(u))
+				carry = vli_add(u, u, mod);
+
+			vli_rshift1(u);
+			if (carry)
+				u[NUM_ECC_DIGITS - 1] |= 0x8000000000000000ull;
+		} else if (EVEN(b)) {
+			vli_rshift1(b);
+
+			if (!EVEN(v))
+				carry = vli_add(v, v, mod);
+
+			vli_rshift1(v);
+			if (carry)
+				v[NUM_ECC_DIGITS - 1] |= 0x8000000000000000ull;
+		} else if (cmp_result > 0) {
+			vli_sub(a, a, b);
+			vli_rshift1(a);
+
+			if (vli_cmp(u, v) < 0)
+				vli_add(u, u, mod);
+
+			vli_sub(u, u, v);
+			if (!EVEN(u))
+				carry = vli_add(u, u, mod);
+
+			vli_rshift1(u);
+			if (carry)
+				u[NUM_ECC_DIGITS - 1] |= 0x8000000000000000ull;
+		} else {
+			vli_sub(b, b, a);
+			vli_rshift1(b);
+
+			if (vli_cmp(v, u) < 0)
+				vli_add(v, v, mod);
+
+			vli_sub(v, v, u);
+			if (!EVEN(v))
+				carry = vli_add(v, v, mod);
+
+			vli_rshift1(v);
+			if (carry)
+				v[NUM_ECC_DIGITS - 1] |= 0x8000000000000000ull;
+		}
+	}
+
+	vli_set(result, u);
+}
+
+/* ------ Point operations ------ */
+
+/* Returns true if p_point is the point at infinity, false otherwise. */
+static bool ecc_point_is_zero(const struct ecc_point *point)
+{
+	return (vli_is_zero(point->x) && vli_is_zero(point->y));
+}
+
+/* Point multiplication algorithm using Montgomery's ladder with co-Z
+ * coordinates. From http://eprint.iacr.org/2011/338.pdf
+ */
+
+/* Double in place */
+static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1)
+{
+	/* t1 = x, t2 = y, t3 = z */
+	u64 t4[NUM_ECC_DIGITS];
+	u64 t5[NUM_ECC_DIGITS];
+
+	if (vli_is_zero(z1))
+		return;
+
+	vli_mod_square_fast(t4, y1);   /* t4 = y1^2 */
+	vli_mod_mult_fast(t5, x1, t4); /* t5 = x1*y1^2 = A */
+	vli_mod_square_fast(t4, t4);   /* t4 = y1^4 */
+	vli_mod_mult_fast(y1, y1, z1); /* t2 = y1*z1 = z3 */
+	vli_mod_square_fast(z1, z1);   /* t3 = z1^2 */
+
+	vli_mod_add(x1, x1, z1, curve_p); /* t1 = x1 + z1^2 */
+	vli_mod_add(z1, z1, z1, curve_p); /* t3 = 2*z1^2 */
+	vli_mod_sub(z1, x1, z1, curve_p); /* t3 = x1 - z1^2 */
+	vli_mod_mult_fast(x1, x1, z1);    /* t1 = x1^2 - z1^4 */
+
+	vli_mod_add(z1, x1, x1, curve_p); /* t3 = 2*(x1^2 - z1^4) */
+	vli_mod_add(x1, x1, z1, curve_p); /* t1 = 3*(x1^2 - z1^4) */
+	if (vli_test_bit(x1, 0)) {
+		u64 carry = vli_add(x1, x1, curve_p);
+		vli_rshift1(x1);
+		x1[NUM_ECC_DIGITS - 1] |= carry << 63;
+	} else {
+		vli_rshift1(x1);
+	}
+	/* t1 = 3/2*(x1^2 - z1^4) = B */
+
+	vli_mod_square_fast(z1, x1);      /* t3 = B^2 */
+	vli_mod_sub(z1, z1, t5, curve_p); /* t3 = B^2 - A */
+	vli_mod_sub(z1, z1, t5, curve_p); /* t3 = B^2 - 2A = x3 */
+	vli_mod_sub(t5, t5, z1, curve_p); /* t5 = A - x3 */
+	vli_mod_mult_fast(x1, x1, t5);    /* t1 = B * (A - x3) */
+	vli_mod_sub(t4, x1, t4, curve_p); /* t4 = B * (A - x3) - y1^4 = y3 */
+
+	vli_set(x1, z1);
+	vli_set(z1, y1);
+	vli_set(y1, t4);
+}
+
+/* Modify (x1, y1) => (x1 * z^2, y1 * z^3) */
+static void apply_z(u64 *x1, u64 *y1, u64 *z)
+{
+	u64 t1[NUM_ECC_DIGITS];
+
+	vli_mod_square_fast(t1, z);    /* z^2 */
+	vli_mod_mult_fast(x1, x1, t1); /* x1 * z^2 */
+	vli_mod_mult_fast(t1, t1, z);  /* z^3 */
+	vli_mod_mult_fast(y1, y1, t1); /* y1 * z^3 */
+}
+
+/* P = (x1, y1) => 2P, (x2, y2) => P' */
+static void xycz_initial_double(u64 *x1, u64 *y1, u64 *x2, u64 *y2,
+				u64 *p_initial_z)
+{
+	u64 z[NUM_ECC_DIGITS];
+
+	vli_set(x2, x1);
+	vli_set(y2, y1);
+
+	vli_clear(z);
+	z[0] = 1;
+
+	if (p_initial_z)
+		vli_set(z, p_initial_z);
+
+	apply_z(x1, y1, z);
+
+	ecc_point_double_jacobian(x1, y1, z);
+
+	apply_z(x2, y2, z);
+}
+
+/* Input P = (x1, y1, Z), Q = (x2, y2, Z)
+ * Output P' = (x1', y1', Z3), P + Q = (x3, y3, Z3)
+ * or P => P', Q => P + Q
+ */
+static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2)
+{
+	/* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */
+	u64 t5[NUM_ECC_DIGITS];
+
+	vli_mod_sub(t5, x2, x1, curve_p); /* t5 = x2 - x1 */
+	vli_mod_square_fast(t5, t5);      /* t5 = (x2 - x1)^2 = A */
+	vli_mod_mult_fast(x1, x1, t5);    /* t1 = x1*A = B */
+	vli_mod_mult_fast(x2, x2, t5);    /* t3 = x2*A = C */
+	vli_mod_sub(y2, y2, y1, curve_p); /* t4 = y2 - y1 */
+	vli_mod_square_fast(t5, y2);      /* t5 = (y2 - y1)^2 = D */
+
+	vli_mod_sub(t5, t5, x1, curve_p); /* t5 = D - B */
+	vli_mod_sub(t5, t5, x2, curve_p); /* t5 = D - B - C = x3 */
+	vli_mod_sub(x2, x2, x1, curve_p); /* t3 = C - B */
+	vli_mod_mult_fast(y1, y1, x2);    /* t2 = y1*(C - B) */
+	vli_mod_sub(x2, x1, t5, curve_p); /* t3 = B - x3 */
+	vli_mod_mult_fast(y2, y2, x2);    /* t4 = (y2 - y1)*(B - x3) */
+	vli_mod_sub(y2, y2, y1, curve_p); /* t4 = y3 */
+
+	vli_set(x2, t5);
+}
+
+/* Input P = (x1, y1, Z), Q = (x2, y2, Z)
+ * Output P + Q = (x3, y3, Z3), P - Q = (x3', y3', Z3)
+ * or P => P - Q, Q => P + Q
+ */
+static void xycz_add_c(u64 *x1, u64 *y1, u64 *x2, u64 *y2)
+{
+	/* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */
+	u64 t5[NUM_ECC_DIGITS];
+	u64 t6[NUM_ECC_DIGITS];
+	u64 t7[NUM_ECC_DIGITS];
+
+	vli_mod_sub(t5, x2, x1, curve_p); /* t5 = x2 - x1 */
+	vli_mod_square_fast(t5, t5);      /* t5 = (x2 - x1)^2 = A */
+	vli_mod_mult_fast(x1, x1, t5);    /* t1 = x1*A = B */
+	vli_mod_mult_fast(x2, x2, t5);    /* t3 = x2*A = C */
+	vli_mod_add(t5, y2, y1, curve_p); /* t4 = y2 + y1 */
+	vli_mod_sub(y2, y2, y1, curve_p); /* t4 = y2 - y1 */
+
+	vli_mod_sub(t6, x2, x1, curve_p); /* t6 = C - B */
+	vli_mod_mult_fast(y1, y1, t6);    /* t2 = y1 * (C - B) */
+	vli_mod_add(t6, x1, x2, curve_p); /* t6 = B + C */
+	vli_mod_square_fast(x2, y2);      /* t3 = (y2 - y1)^2 */
+	vli_mod_sub(x2, x2, t6, curve_p); /* t3 = x3 */
+
+	vli_mod_sub(t7, x1, x2, curve_p); /* t7 = B - x3 */
+	vli_mod_mult_fast(y2, y2, t7);    /* t4 = (y2 - y1)*(B - x3) */
+	vli_mod_sub(y2, y2, y1, curve_p); /* t4 = y3 */
+
+	vli_mod_square_fast(t7, t5);      /* t7 = (y2 + y1)^2 = F */
+	vli_mod_sub(t7, t7, t6, curve_p); /* t7 = x3' */
+	vli_mod_sub(t6, t7, x1, curve_p); /* t6 = x3' - B */
+	vli_mod_mult_fast(t6, t6, t5);    /* t6 = (y2 + y1)*(x3' - B) */
+	vli_mod_sub(y1, t6, y1, curve_p); /* t2 = y3' */
+
+	vli_set(x1, t7);
+}
+
+static void ecc_point_mult(struct ecc_point *result,
+			   const struct ecc_point *point, u64 *scalar,
+			   u64 *initial_z, int num_bits)
+{
+	/* R0 and R1 */
+	u64 rx[2][NUM_ECC_DIGITS];
+	u64 ry[2][NUM_ECC_DIGITS];
+	u64 z[NUM_ECC_DIGITS];
+	int i, nb;
+
+	vli_set(rx[1], point->x);
+	vli_set(ry[1], point->y);
+
+	xycz_initial_double(rx[1], ry[1], rx[0], ry[0], initial_z);
+
+	for (i = num_bits - 2; i > 0; i--) {
+		nb = !vli_test_bit(scalar, i);
+		xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb]);
+		xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb]);
+	}
+
+	nb = !vli_test_bit(scalar, 0);
+	xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb]);
+
+	/* Find final 1/Z value. */
+	vli_mod_sub(z, rx[1], rx[0], curve_p); /* X1 - X0 */
+	vli_mod_mult_fast(z, z, ry[1 - nb]); /* Yb * (X1 - X0) */
+	vli_mod_mult_fast(z, z, point->x);   /* xP * Yb * (X1 - X0) */
+	vli_mod_inv(z, z, curve_p);          /* 1 / (xP * Yb * (X1 - X0)) */
+	vli_mod_mult_fast(z, z, point->y);   /* yP / (xP * Yb * (X1 - X0)) */
+	vli_mod_mult_fast(z, z, rx[1 - nb]); /* Xb * yP / (xP * Yb * (X1 - X0)) */
+	/* End 1/Z calculation */
+
+	xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb]);
+
+	apply_z(rx[0], ry[0], z);
+
+	vli_set(result->x, rx[0]);
+	vli_set(result->y, ry[0]);
+}
+
+static void ecc_bytes2native(const u8 bytes[ECC_BYTES],
+			     u64 native[NUM_ECC_DIGITS])
+{
+	int i;
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++) {
+		const u8 *digit = bytes + 8 * (NUM_ECC_DIGITS - 1 - i);
+
+		native[NUM_ECC_DIGITS - 1 - i] =
+				((u64) digit[0] << 0) |
+				((u64) digit[1] << 8) |
+				((u64) digit[2] << 16) |
+				((u64) digit[3] << 24) |
+				((u64) digit[4] << 32) |
+				((u64) digit[5] << 40) |
+				((u64) digit[6] << 48) |
+				((u64) digit[7] << 56);
+	}
+}
+
+static void ecc_native2bytes(const u64 native[NUM_ECC_DIGITS],
+			     u8 bytes[ECC_BYTES])
+{
+	int i;
+
+	for (i = 0; i < NUM_ECC_DIGITS; i++) {
+		u8 *digit = bytes + 8 * (NUM_ECC_DIGITS - 1 - i);
+
+		digit[0] = native[NUM_ECC_DIGITS - 1 - i] >> 0;
+		digit[1] = native[NUM_ECC_DIGITS - 1 - i] >> 8;
+		digit[2] = native[NUM_ECC_DIGITS - 1 - i] >> 16;
+		digit[3] = native[NUM_ECC_DIGITS - 1 - i] >> 24;
+		digit[4] = native[NUM_ECC_DIGITS - 1 - i] >> 32;
+		digit[5] = native[NUM_ECC_DIGITS - 1 - i] >> 40;
+		digit[6] = native[NUM_ECC_DIGITS - 1 - i] >> 48;
+		digit[7] = native[NUM_ECC_DIGITS - 1 - i] >> 56;
+	}
+}
+
+bool ecc_make_key(u8 public_key[64], u8 private_key[32])
+{
+	struct ecc_point pk;
+	u64 priv[NUM_ECC_DIGITS];
+	unsigned int tries = 0;
+
+	do {
+		if (tries++ >= MAX_TRIES)
+			return false;
+
+		get_random_bytes(priv, ECC_BYTES);
+
+		if (vli_is_zero(priv))
+			continue;
+
+		/* Make sure the private key is in the range [1, n-1]. */
+		if (vli_cmp(curve_n, priv) != 1)
+			continue;
+
+		ecc_point_mult(&pk, &curve_g, priv, NULL, vli_num_bits(priv));
+	} while (ecc_point_is_zero(&pk));
+
+	ecc_native2bytes(priv, private_key);
+	ecc_native2bytes(pk.x, public_key);
+	ecc_native2bytes(pk.y, &public_key[32]);
+
+	return true;
+}
+
+bool ecdh_shared_secret(const u8 public_key[64], const u8 private_key[32],
+		        u8 secret[32])
+{
+	u64 priv[NUM_ECC_DIGITS];
+	u64 rand[NUM_ECC_DIGITS];
+	struct ecc_point product, pk;
+
+	get_random_bytes(rand, ECC_BYTES);
+
+	ecc_bytes2native(public_key, pk.x);
+	ecc_bytes2native(&public_key[32], pk.y);
+	ecc_bytes2native(private_key, priv);
+
+	ecc_point_mult(&product, &pk, priv, rand, vli_num_bits(priv));
+
+	ecc_native2bytes(product.x, secret);
+
+	return !ecc_point_is_zero(&product);
+}