Merge branch 'master' into Basilisk-releasev2018.04.26

1 files changed, 504 insertions, 4 deletions

diff --git a/security/nss/lib/freebl/ecl/curve25519_64.c b/security/nss/lib/freebl/ecl/curve25519_64.c
index a2e4296bbf..65f6bd41b5 100644
--- a/security/nss/lib/freebl/ecl/curve25519_64.c
+++ b/security/nss/lib/freebl/ecl/curve25519_64.c
@@ -2,13 +2,513 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+/*
+ * Derived from public domain C code by Adan Langley and Daniel J. Bernstein
+ */
+
+#include "uint128.h"
+
 #include "ecl-priv.h"
-#include "../verified/Hacl_Curve25519.h"
+#include "mpi.h"
+
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+typedef uint8_t u8;
+typedef uint64_t felem;
+
+/* Sum two numbers: output += in */
+static void
+fsum(felem *output, const felem *in)
+{
+    unsigned i;
+    for (i = 0; i < 5; ++i) {
+        output[i] += in[i];
+    }
+}
+
+/* Find the difference of two numbers: output = in - output
+ * (note the order of the arguments!)
+ */
+static void
+fdifference_backwards(felem *ioutput, const felem *iin)
+{
+    static const int64_t twotothe51 = ((int64_t)1l << 51);
+    const int64_t *in = (const int64_t *)iin;
+    int64_t *out = (int64_t *)ioutput;
+
+    out[0] = in[0] - out[0];
+    out[1] = in[1] - out[1];
+    out[2] = in[2] - out[2];
+    out[3] = in[3] - out[3];
+    out[4] = in[4] - out[4];
+
+    // An arithmetic shift right of 63 places turns a positive number to 0 and a
+    // negative number to all 1's. This gives us a bitmask that lets us avoid
+    // side-channel prone branches.
+    int64_t t;
+
+#define NEGCHAIN(a, b)        \
+    t = out[a] >> 63;         \
+    out[a] += twotothe51 & t; \
+    out[b] -= 1 & t;
+
+#define NEGCHAIN19(a, b)      \
+    t = out[a] >> 63;         \
+    out[a] += twotothe51 & t; \
+    out[b] -= 19 & t;
+
+    NEGCHAIN(0, 1);
+    NEGCHAIN(1, 2);
+    NEGCHAIN(2, 3);
+    NEGCHAIN(3, 4);
+    NEGCHAIN19(4, 0);
+    NEGCHAIN(0, 1);
+    NEGCHAIN(1, 2);
+    NEGCHAIN(2, 3);
+    NEGCHAIN(3, 4);
+}
+
+/* Multiply a number by a scalar: output = in * scalar */
+static void
+fscalar_product(felem *output, const felem *in,
+                const felem scalar)
+{
+    uint128_t tmp, tmp2;
+
+    tmp = mul6464(in[0], scalar);
+    output[0] = mask51(tmp);
+
+    tmp2 = mul6464(in[1], scalar);
+    tmp = add128(tmp2, rshift128(tmp, 51));
+    output[1] = mask51(tmp);
+
+    tmp2 = mul6464(in[2], scalar);
+    tmp = add128(tmp2, rshift128(tmp, 51));
+    output[2] = mask51(tmp);
+
+    tmp2 = mul6464(in[3], scalar);
+    tmp = add128(tmp2, rshift128(tmp, 51));
+    output[3] = mask51(tmp);
+
+    tmp2 = mul6464(in[4], scalar);
+    tmp = add128(tmp2, rshift128(tmp, 51));
+    output[4] = mask51(tmp);
+
+    output[0] += mask_lower(rshift128(tmp, 51)) * 19;
+}
+
+/* Multiply two numbers: output = in2 * in
+ *
+ * output must be distinct to both inputs. The inputs are reduced coefficient
+ * form, the output is not.
+ */
+static void
+fmul(felem *output, const felem *in2, const felem *in)
+{
+    uint128_t t0, t1, t2, t3, t4, t5, t6, t7, t8;
+
+    t0 = mul6464(in[0], in2[0]);
+    t1 = add128(mul6464(in[1], in2[0]), mul6464(in[0], in2[1]));
+    t2 = add128(add128(mul6464(in[0], in2[2]),
+                       mul6464(in[2], in2[0])),
+                mul6464(in[1], in2[1]));
+    t3 = add128(add128(add128(mul6464(in[0], in2[3]),
+                              mul6464(in[3], in2[0])),
+                       mul6464(in[1], in2[2])),
+                mul6464(in[2], in2[1]));
+    t4 = add128(add128(add128(add128(mul6464(in[0], in2[4]),
+                                     mul6464(in[4], in2[0])),
+                              mul6464(in[3], in2[1])),
+                       mul6464(in[1], in2[3])),
+                mul6464(in[2], in2[2]));
+    t5 = add128(add128(add128(mul6464(in[4], in2[1]),
+                              mul6464(in[1], in2[4])),
+                       mul6464(in[2], in2[3])),
+                mul6464(in[3], in2[2]));
+    t6 = add128(add128(mul6464(in[4], in2[2]),
+                       mul6464(in[2], in2[4])),
+                mul6464(in[3], in2[3]));
+    t7 = add128(mul6464(in[3], in2[4]), mul6464(in[4], in2[3]));
+    t8 = mul6464(in[4], in2[4]);
+
+    t0 = add128(t0, mul12819(t5));
+    t1 = add128(t1, mul12819(t6));
+    t2 = add128(t2, mul12819(t7));
+    t3 = add128(t3, mul12819(t8));
+
+    t1 = add128(t1, rshift128(t0, 51));
+    t0 = mask51full(t0);
+    t2 = add128(t2, rshift128(t1, 51));
+    t1 = mask51full(t1);
+    t3 = add128(t3, rshift128(t2, 51));
+    t4 = add128(t4, rshift128(t3, 51));
+    t0 = add128(t0, mul12819(rshift128(t4, 51)));
+    t1 = add128(t1, rshift128(t0, 51));
+    t2 = mask51full(t2);
+    t2 = add128(t2, rshift128(t1, 51));
+
+    output[0] = mask51(t0);
+    output[1] = mask51(t1);
+    output[2] = mask_lower(t2);
+    output[3] = mask51(t3);
+    output[4] = mask51(t4);
+}
+
+static void
+fsquare(felem *output, const felem *in)
+{
+    uint128_t t0, t1, t2, t3, t4, t5, t6, t7, t8;
+
+    t0 = mul6464(in[0], in[0]);
+    t1 = lshift128(mul6464(in[0], in[1]), 1);
+    t2 = add128(lshift128(mul6464(in[0], in[2]), 1),
+                mul6464(in[1], in[1]));
+    t3 = add128(lshift128(mul6464(in[0], in[3]), 1),
+                lshift128(mul6464(in[1], in[2]), 1));
+    t4 = add128(add128(lshift128(mul6464(in[0], in[4]), 1),
+                       lshift128(mul6464(in[3], in[1]), 1)),
+                mul6464(in[2], in[2]));
+    t5 = add128(lshift128(mul6464(in[4], in[1]), 1),
+                lshift128(mul6464(in[2], in[3]), 1));
+    t6 = add128(lshift128(mul6464(in[4], in[2]), 1),
+                mul6464(in[3], in[3]));
+    t7 = lshift128(mul6464(in[3], in[4]), 1);
+    t8 = mul6464(in[4], in[4]);
+
+    t0 = add128(t0, mul12819(t5));
+    t1 = add128(t1, mul12819(t6));
+    t2 = add128(t2, mul12819(t7));
+    t3 = add128(t3, mul12819(t8));
+
+    t1 = add128(t1, rshift128(t0, 51));
+    t0 = mask51full(t0);
+    t2 = add128(t2, rshift128(t1, 51));
+    t1 = mask51full(t1);
+    t3 = add128(t3, rshift128(t2, 51));
+    t4 = add128(t4, rshift128(t3, 51));
+    t0 = add128(t0, mul12819(rshift128(t4, 51)));
+    t1 = add128(t1, rshift128(t0, 51));
+
+    output[0] = mask51(t0);
+    output[1] = mask_lower(t1);
+    output[2] = mask51(t2);
+    output[3] = mask51(t3);
+    output[4] = mask51(t4);
+}
+
+/* Take a 32-byte number and expand it into polynomial form */
+static void NO_SANITIZE_ALIGNMENT
+fexpand(felem *output, const u8 *in)
+{
+    output[0] = *((const uint64_t *)(in)) & MASK51;
+    output[1] = (*((const uint64_t *)(in + 6)) >> 3) & MASK51;
+    output[2] = (*((const uint64_t *)(in + 12)) >> 6) & MASK51;
+    output[3] = (*((const uint64_t *)(in + 19)) >> 1) & MASK51;
+    output[4] = (*((const uint64_t *)(in + 24)) >> 12) & MASK51;
+}
+
+/* Take a fully reduced polynomial form number and contract it into a
+ * 32-byte array
+ */
+static void
+fcontract(u8 *output, const felem *input)
+{
+    uint128_t t0 = init128x(input[0]);
+    uint128_t t1 = init128x(input[1]);
+    uint128_t t2 = init128x(input[2]);
+    uint128_t t3 = init128x(input[3]);
+    uint128_t t4 = init128x(input[4]);
+    uint128_t tmp = init128x(19);
+
+    t1 = add128(t1, rshift128(t0, 51));
+    t0 = mask51full(t0);
+    t2 = add128(t2, rshift128(t1, 51));
+    t1 = mask51full(t1);
+    t3 = add128(t3, rshift128(t2, 51));
+    t2 = mask51full(t2);
+    t4 = add128(t4, rshift128(t3, 51));
+    t3 = mask51full(t3);
+    t0 = add128(t0, mul12819(rshift128(t4, 51)));
+    t4 = mask51full(t4);
+
+    t1 = add128(t1, rshift128(t0, 51));
+    t0 = mask51full(t0);
+    t2 = add128(t2, rshift128(t1, 51));
+    t1 = mask51full(t1);
+    t3 = add128(t3, rshift128(t2, 51));
+    t2 = mask51full(t2);
+    t4 = add128(t4, rshift128(t3, 51));
+    t3 = mask51full(t3);
+    t0 = add128(t0, mul12819(rshift128(t4, 51)));
+    t4 = mask51full(t4);
+
+    /* now t is between 0 and 2^255-1, properly carried. */
+    /* case 1: between 0 and 2^255-20. case 2: between 2^255-19 and 2^255-1. */
+
+    t0 = add128(t0, tmp);
+
+    t1 = add128(t1, rshift128(t0, 51));
+    t0 = mask51full(t0);
+    t2 = add128(t2, rshift128(t1, 51));
+    t1 = mask51full(t1);
+    t3 = add128(t3, rshift128(t2, 51));
+    t2 = mask51full(t2);
+    t4 = add128(t4, rshift128(t3, 51));
+    t3 = mask51full(t3);
+    t0 = add128(t0, mul12819(rshift128(t4, 51)));
+    t4 = mask51full(t4);
+
+    /* now between 19 and 2^255-1 in both cases, and offset by 19. */
+
+    t0 = add128(t0, init128x(0x8000000000000 - 19));
+    tmp = init128x(0x8000000000000 - 1);
+    t1 = add128(t1, tmp);
+    t2 = add128(t2, tmp);
+    t3 = add128(t3, tmp);
+    t4 = add128(t4, tmp);
+
+    /* now between 2^255 and 2^256-20, and offset by 2^255. */
+
+    t1 = add128(t1, rshift128(t0, 51));
+    t0 = mask51full(t0);
+    t2 = add128(t2, rshift128(t1, 51));
+    t1 = mask51full(t1);
+    t3 = add128(t3, rshift128(t2, 51));
+    t2 = mask51full(t2);
+    t4 = add128(t4, rshift128(t3, 51));
+    t3 = mask51full(t3);
+    t4 = mask51full(t4);
+
+    *((uint64_t *)(output)) = mask_lower(t0) | mask_lower(t1) << 51;
+    *((uint64_t *)(output + 8)) = (mask_lower(t1) >> 13) | (mask_lower(t2) << 38);
+    *((uint64_t *)(output + 16)) = (mask_lower(t2) >> 26) | (mask_lower(t3) << 25);
+    *((uint64_t *)(output + 24)) = (mask_lower(t3) >> 39) | (mask_lower(t4) << 12);
+}
+
+/* Input: Q, Q', Q-Q'
+ * Output: 2Q, Q+Q'
+ *
+ *   x2 z3: long form
+ *   x3 z3: long form
+ *   x z: short form, destroyed
+ *   xprime zprime: short form, destroyed
+ *   qmqp: short form, preserved
+ */
+static void
+fmonty(felem *x2, felem *z2,         /* output 2Q */
+       felem *x3, felem *z3,         /* output Q + Q' */
+       felem *x, felem *z,           /* input Q */
+       felem *xprime, felem *zprime, /* input Q' */
+       const felem *qmqp /* input Q - Q' */)
+{
+    felem origx[5], origxprime[5], zzz[5], xx[5], zz[5], xxprime[5], zzprime[5],
+        zzzprime[5];
+
+    memcpy(origx, x, 5 * sizeof(felem));
+    fsum(x, z);
+    fdifference_backwards(z, origx); // does x - z
+
+    memcpy(origxprime, xprime, sizeof(felem) * 5);
+    fsum(xprime, zprime);
+    fdifference_backwards(zprime, origxprime);
+    fmul(xxprime, xprime, z);
+    fmul(zzprime, x, zprime);
+    memcpy(origxprime, xxprime, sizeof(felem) * 5);
+    fsum(xxprime, zzprime);
+    fdifference_backwards(zzprime, origxprime);
+    fsquare(x3, xxprime);
+    fsquare(zzzprime, zzprime);
+    fmul(z3, zzzprime, qmqp);
+
+    fsquare(xx, x);
+    fsquare(zz, z);
+    fmul(x2, xx, zz);
+    fdifference_backwards(zz, xx); // does zz = xx - zz
+    fscalar_product(zzz, zz, 121665);
+    fsum(zzz, xx);
+    fmul(z2, zz, zzz);
+}
+
+// -----------------------------------------------------------------------------
+// Maybe swap the contents of two felem arrays (@a and @b), each @len elements
+// long. Perform the swap iff @swap is non-zero.
+//
+// This function performs the swap without leaking any side-channel
+// information.
+// -----------------------------------------------------------------------------
+static void
+swap_conditional(felem *a, felem *b, unsigned len, felem iswap)
+{
+    unsigned i;
+    const felem swap = 1 + ~iswap;
+
+    for (i = 0; i < len; ++i) {
+        const felem x = swap & (a[i] ^ b[i]);
+        a[i] ^= x;
+        b[i] ^= x;
+    }
+}
+
+/* Calculates nQ where Q is the x-coordinate of a point on the curve
+ *
+ *   resultx/resultz: the x coordinate of the resulting curve point (short form)
+ *   n: a 32-byte number
+ *   q: a point of the curve (short form)
+ */
+static void
+cmult(felem *resultx, felem *resultz, const u8 *n, const felem *q)
+{
+    felem a[5] = { 0 }, b[5] = { 1 }, c[5] = { 1 }, d[5] = { 0 };
+    felem *nqpqx = a, *nqpqz = b, *nqx = c, *nqz = d, *t;
+    felem e[5] = { 0 }, f[5] = { 1 }, g[5] = { 0 }, h[5] = { 1 };
+    felem *nqpqx2 = e, *nqpqz2 = f, *nqx2 = g, *nqz2 = h;
+
+    unsigned i, j;
+
+    memcpy(nqpqx, q, sizeof(felem) * 5);
+
+    for (i = 0; i < 32; ++i) {
+        u8 byte = n[31 - i];
+        for (j = 0; j < 8; ++j) {
+            const felem bit = byte >> 7;
+
+            swap_conditional(nqx, nqpqx, 5, bit);
+            swap_conditional(nqz, nqpqz, 5, bit);
+            fmonty(nqx2, nqz2, nqpqx2, nqpqz2, nqx, nqz, nqpqx, nqpqz, q);
+            swap_conditional(nqx2, nqpqx2, 5, bit);
+            swap_conditional(nqz2, nqpqz2, 5, bit);
+
+            t = nqx;
+            nqx = nqx2;
+            nqx2 = t;
+            t = nqz;
+            nqz = nqz2;
+            nqz2 = t;
+            t = nqpqx;
+            nqpqx = nqpqx2;
+            nqpqx2 = t;
+            t = nqpqz;
+            nqpqz = nqpqz2;
+            nqpqz2 = t;
+
+            byte <<= 1;
+        }
+    }
+
+    memcpy(resultx, nqx, sizeof(felem) * 5);
+    memcpy(resultz, nqz, sizeof(felem) * 5);
+}
+
+// -----------------------------------------------------------------------------
+// Shamelessly copied from djb's code
+// -----------------------------------------------------------------------------
+static void
+crecip(felem *out, const felem *z)
+{
+    felem z2[5];
+    felem z9[5];
+    felem z11[5];
+    felem z2_5_0[5];
+    felem z2_10_0[5];
+    felem z2_20_0[5];
+    felem z2_50_0[5];
+    felem z2_100_0[5];
+    felem t0[5];
+    felem t1[5];
+    int i;
+
+    /* 2 */ fsquare(z2, z);
+    /* 4 */ fsquare(t1, z2);
+    /* 8 */ fsquare(t0, t1);
+    /* 9 */ fmul(z9, t0, z);
+    /* 11 */ fmul(z11, z9, z2);
+    /* 22 */ fsquare(t0, z11);
+    /* 2^5 - 2^0 = 31 */ fmul(z2_5_0, t0, z9);
+
+    /* 2^6 - 2^1 */ fsquare(t0, z2_5_0);
+    /* 2^7 - 2^2 */ fsquare(t1, t0);
+    /* 2^8 - 2^3 */ fsquare(t0, t1);
+    /* 2^9 - 2^4 */ fsquare(t1, t0);
+    /* 2^10 - 2^5 */ fsquare(t0, t1);
+    /* 2^10 - 2^0 */ fmul(z2_10_0, t0, z2_5_0);
+
+    /* 2^11 - 2^1 */ fsquare(t0, z2_10_0);
+    /* 2^12 - 2^2 */ fsquare(t1, t0);
+    /* 2^20 - 2^10 */ for (i = 2; i < 10; i += 2) {
+        fsquare(t0, t1);
+        fsquare(t1, t0);
+    }
+    /* 2^20 - 2^0 */ fmul(z2_20_0, t1, z2_10_0);
+
+    /* 2^21 - 2^1 */ fsquare(t0, z2_20_0);
+    /* 2^22 - 2^2 */ fsquare(t1, t0);
+    /* 2^40 - 2^20 */ for (i = 2; i < 20; i += 2) {
+        fsquare(t0, t1);
+        fsquare(t1, t0);
+    }
+    /* 2^40 - 2^0 */ fmul(t0, t1, z2_20_0);
+
+    /* 2^41 - 2^1 */ fsquare(t1, t0);
+    /* 2^42 - 2^2 */ fsquare(t0, t1);
+    /* 2^50 - 2^10 */ for (i = 2; i < 10; i += 2) {
+        fsquare(t1, t0);
+        fsquare(t0, t1);
+    }
+    /* 2^50 - 2^0 */ fmul(z2_50_0, t0, z2_10_0);
+
+    /* 2^51 - 2^1 */ fsquare(t0, z2_50_0);
+    /* 2^52 - 2^2 */ fsquare(t1, t0);
+    /* 2^100 - 2^50 */ for (i = 2; i < 50; i += 2) {
+        fsquare(t0, t1);
+        fsquare(t1, t0);
+    }
+    /* 2^100 - 2^0 */ fmul(z2_100_0, t1, z2_50_0);
+
+    /* 2^101 - 2^1 */ fsquare(t1, z2_100_0);
+    /* 2^102 - 2^2 */ fsquare(t0, t1);
+    /* 2^200 - 2^100 */ for (i = 2; i < 100; i += 2) {
+        fsquare(t1, t0);
+        fsquare(t0, t1);
+    }
+    /* 2^200 - 2^0 */ fmul(t1, t0, z2_100_0);
+
+    /* 2^201 - 2^1 */ fsquare(t0, t1);
+    /* 2^202 - 2^2 */ fsquare(t1, t0);
+    /* 2^250 - 2^50 */ for (i = 2; i < 50; i += 2) {
+        fsquare(t0, t1);
+        fsquare(t1, t0);
+    }
+    /* 2^250 - 2^0 */ fmul(t0, t1, z2_50_0);
+
+    /* 2^251 - 2^1 */ fsquare(t1, t0);
+    /* 2^252 - 2^2 */ fsquare(t0, t1);
+    /* 2^253 - 2^3 */ fsquare(t1, t0);
+    /* 2^254 - 2^4 */ fsquare(t0, t1);
+    /* 2^255 - 2^5 */ fsquare(t1, t0);
+    /* 2^255 - 21 */ fmul(out, t1, z11);
+}
 
 SECStatus
-ec_Curve25519_mul(uint8_t *mypublic, const uint8_t *secret, const uint8_t *basepoint)
+ec_Curve25519_mul(uint8_t *mypublic, const uint8_t *secret,
+                  const uint8_t *basepoint)
 {
-    // Note: this cast is safe because HaCl* state has a post-condition that only "mypublic" changed.
-    Hacl_Curve25519_crypto_scalarmult(mypublic, (uint8_t *)secret, (uint8_t *)basepoint);
+    felem bp[5], x[5], z[5], zmone[5];
+    uint8_t e[32];
+    int i;
+
+    for (i = 0; i < 32; ++i) {
+        e[i] = secret[i];
+    }
+    e[0] &= 248;
+    e[31] &= 127;
+    e[31] |= 64;
+    fexpand(bp, basepoint);
+    cmult(x, z, e, bp);
+    crecip(zmone, z);
+    fmul(z, x, zmone);
+    fcontract(mypublic, z);
+
     return 0;
 }