Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/lib/mpi/Makefile b/lib/mpi/Makefile
index d5874a7..6e6ef9a 100644
--- a/lib/mpi/Makefile
+++ b/lib/mpi/Makefile
@@ -13,9 +13,16 @@
generic_mpih-rshift.o \
generic_mpih-sub1.o \
generic_mpih-add1.o \
+ ec.o \
mpicoder.o \
+ mpi-add.o \
mpi-bit.o \
mpi-cmp.o \
+ mpi-sub-ui.o \
+ mpi-div.o \
+ mpi-inv.o \
+ mpi-mod.o \
+ mpi-mul.o \
mpih-cmp.o \
mpih-div.o \
mpih-mul.o \
diff --git a/lib/mpi/ec.c b/lib/mpi/ec.c
new file mode 100644
index 0000000..c214701
--- /dev/null
+++ b/lib/mpi/ec.c
@@ -0,0 +1,1509 @@
+/* ec.c - Elliptic Curve functions
+ * Copyright (C) 2007 Free Software Foundation, Inc.
+ * Copyright (C) 2013 g10 Code GmbH
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgcrypt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+#define point_init(a) mpi_point_init((a))
+#define point_free(a) mpi_point_free_parts((a))
+
+#define log_error(fmt, ...) pr_err(fmt, ##__VA_ARGS__)
+#define log_fatal(fmt, ...) pr_err(fmt, ##__VA_ARGS__)
+
+#define DIM(v) (sizeof(v)/sizeof((v)[0]))
+
+
+/* Create a new point option. NBITS gives the size in bits of one
+ * coordinate; it is only used to pre-allocate some resources and
+ * might also be passed as 0 to use a default value.
+ */
+MPI_POINT mpi_point_new(unsigned int nbits)
+{
+ MPI_POINT p;
+
+ (void)nbits; /* Currently not used. */
+
+ p = kmalloc(sizeof(*p), GFP_KERNEL);
+ if (p)
+ mpi_point_init(p);
+ return p;
+}
+EXPORT_SYMBOL_GPL(mpi_point_new);
+
+/* Release the point object P. P may be NULL. */
+void mpi_point_release(MPI_POINT p)
+{
+ if (p) {
+ mpi_point_free_parts(p);
+ kfree(p);
+ }
+}
+EXPORT_SYMBOL_GPL(mpi_point_release);
+
+/* Initialize the fields of a point object. gcry_mpi_point_free_parts
+ * may be used to release the fields.
+ */
+void mpi_point_init(MPI_POINT p)
+{
+ p->x = mpi_new(0);
+ p->y = mpi_new(0);
+ p->z = mpi_new(0);
+}
+EXPORT_SYMBOL_GPL(mpi_point_init);
+
+/* Release the parts of a point object. */
+void mpi_point_free_parts(MPI_POINT p)
+{
+ mpi_free(p->x); p->x = NULL;
+ mpi_free(p->y); p->y = NULL;
+ mpi_free(p->z); p->z = NULL;
+}
+EXPORT_SYMBOL_GPL(mpi_point_free_parts);
+
+/* Set the value from S into D. */
+static void point_set(MPI_POINT d, MPI_POINT s)
+{
+ mpi_set(d->x, s->x);
+ mpi_set(d->y, s->y);
+ mpi_set(d->z, s->z);
+}
+
+static void point_resize(MPI_POINT p, struct mpi_ec_ctx *ctx)
+{
+ size_t nlimbs = ctx->p->nlimbs;
+
+ mpi_resize(p->x, nlimbs);
+ p->x->nlimbs = nlimbs;
+ mpi_resize(p->z, nlimbs);
+ p->z->nlimbs = nlimbs;
+
+ if (ctx->model != MPI_EC_MONTGOMERY) {
+ mpi_resize(p->y, nlimbs);
+ p->y->nlimbs = nlimbs;
+ }
+}
+
+static void point_swap_cond(MPI_POINT d, MPI_POINT s, unsigned long swap,
+ struct mpi_ec_ctx *ctx)
+{
+ mpi_swap_cond(d->x, s->x, swap);
+ if (ctx->model != MPI_EC_MONTGOMERY)
+ mpi_swap_cond(d->y, s->y, swap);
+ mpi_swap_cond(d->z, s->z, swap);
+}
+
+
+/* W = W mod P. */
+static void ec_mod(MPI w, struct mpi_ec_ctx *ec)
+{
+ if (ec->t.p_barrett)
+ mpi_mod_barrett(w, w, ec->t.p_barrett);
+ else
+ mpi_mod(w, w, ec->p);
+}
+
+static void ec_addm(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx)
+{
+ mpi_add(w, u, v);
+ ec_mod(w, ctx);
+}
+
+static void ec_subm(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ec)
+{
+ mpi_sub(w, u, v);
+ while (w->sign)
+ mpi_add(w, w, ec->p);
+ /*ec_mod(w, ec);*/
+}
+
+static void ec_mulm(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx)
+{
+ mpi_mul(w, u, v);
+ ec_mod(w, ctx);
+}
+
+/* W = 2 * U mod P. */
+static void ec_mul2(MPI w, MPI u, struct mpi_ec_ctx *ctx)
+{
+ mpi_lshift(w, u, 1);
+ ec_mod(w, ctx);
+}
+
+static void ec_powm(MPI w, const MPI b, const MPI e,
+ struct mpi_ec_ctx *ctx)
+{
+ mpi_powm(w, b, e, ctx->p);
+ /* mpi_abs(w); */
+}
+
+/* Shortcut for
+ * ec_powm(B, B, mpi_const(MPI_C_TWO), ctx);
+ * for easier optimization.
+ */
+static void ec_pow2(MPI w, const MPI b, struct mpi_ec_ctx *ctx)
+{
+ /* Using mpi_mul is slightly faster (at least on amd64). */
+ /* mpi_powm(w, b, mpi_const(MPI_C_TWO), ctx->p); */
+ ec_mulm(w, b, b, ctx);
+}
+
+/* Shortcut for
+ * ec_powm(B, B, mpi_const(MPI_C_THREE), ctx);
+ * for easier optimization.
+ */
+static void ec_pow3(MPI w, const MPI b, struct mpi_ec_ctx *ctx)
+{
+ mpi_powm(w, b, mpi_const(MPI_C_THREE), ctx->p);
+}
+
+static void ec_invm(MPI x, MPI a, struct mpi_ec_ctx *ctx)
+{
+ if (!mpi_invm(x, a, ctx->p))
+ log_error("ec_invm: inverse does not exist:\n");
+}
+
+static void mpih_set_cond(mpi_ptr_t wp, mpi_ptr_t up,
+ mpi_size_t usize, unsigned long set)
+{
+ mpi_size_t i;
+ mpi_limb_t mask = ((mpi_limb_t)0) - set;
+ mpi_limb_t x;
+
+ for (i = 0; i < usize; i++) {
+ x = mask & (wp[i] ^ up[i]);
+ wp[i] = wp[i] ^ x;
+ }
+}
+
+/* Routines for 2^255 - 19. */
+
+#define LIMB_SIZE_25519 ((256+BITS_PER_MPI_LIMB-1)/BITS_PER_MPI_LIMB)
+
+static void ec_addm_25519(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx)
+{
+ mpi_ptr_t wp, up, vp;
+ mpi_size_t wsize = LIMB_SIZE_25519;
+ mpi_limb_t n[LIMB_SIZE_25519];
+ mpi_limb_t borrow;
+
+ if (w->nlimbs != wsize || u->nlimbs != wsize || v->nlimbs != wsize)
+ log_bug("addm_25519: different sizes\n");
+
+ memset(n, 0, sizeof(n));
+ up = u->d;
+ vp = v->d;
+ wp = w->d;
+
+ mpihelp_add_n(wp, up, vp, wsize);
+ borrow = mpihelp_sub_n(wp, wp, ctx->p->d, wsize);
+ mpih_set_cond(n, ctx->p->d, wsize, (borrow != 0UL));
+ mpihelp_add_n(wp, wp, n, wsize);
+ wp[LIMB_SIZE_25519-1] &= ~((mpi_limb_t)1 << (255 % BITS_PER_MPI_LIMB));
+}
+
+static void ec_subm_25519(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx)
+{
+ mpi_ptr_t wp, up, vp;
+ mpi_size_t wsize = LIMB_SIZE_25519;
+ mpi_limb_t n[LIMB_SIZE_25519];
+ mpi_limb_t borrow;
+
+ if (w->nlimbs != wsize || u->nlimbs != wsize || v->nlimbs != wsize)
+ log_bug("subm_25519: different sizes\n");
+
+ memset(n, 0, sizeof(n));
+ up = u->d;
+ vp = v->d;
+ wp = w->d;
+
+ borrow = mpihelp_sub_n(wp, up, vp, wsize);
+ mpih_set_cond(n, ctx->p->d, wsize, (borrow != 0UL));
+ mpihelp_add_n(wp, wp, n, wsize);
+ wp[LIMB_SIZE_25519-1] &= ~((mpi_limb_t)1 << (255 % BITS_PER_MPI_LIMB));
+}
+
+static void ec_mulm_25519(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx)
+{
+ mpi_ptr_t wp, up, vp;
+ mpi_size_t wsize = LIMB_SIZE_25519;
+ mpi_limb_t n[LIMB_SIZE_25519*2];
+ mpi_limb_t m[LIMB_SIZE_25519+1];
+ mpi_limb_t cy;
+ int msb;
+
+ (void)ctx;
+ if (w->nlimbs != wsize || u->nlimbs != wsize || v->nlimbs != wsize)
+ log_bug("mulm_25519: different sizes\n");
+
+ up = u->d;
+ vp = v->d;
+ wp = w->d;
+
+ mpihelp_mul_n(n, up, vp, wsize);
+ memcpy(wp, n, wsize * BYTES_PER_MPI_LIMB);
+ wp[LIMB_SIZE_25519-1] &= ~((mpi_limb_t)1 << (255 % BITS_PER_MPI_LIMB));
+
+ memcpy(m, n+LIMB_SIZE_25519-1, (wsize+1) * BYTES_PER_MPI_LIMB);
+ mpihelp_rshift(m, m, LIMB_SIZE_25519+1, (255 % BITS_PER_MPI_LIMB));
+
+ memcpy(n, m, wsize * BYTES_PER_MPI_LIMB);
+ cy = mpihelp_lshift(m, m, LIMB_SIZE_25519, 4);
+ m[LIMB_SIZE_25519] = cy;
+ cy = mpihelp_add_n(m, m, n, wsize);
+ m[LIMB_SIZE_25519] += cy;
+ cy = mpihelp_add_n(m, m, n, wsize);
+ m[LIMB_SIZE_25519] += cy;
+ cy = mpihelp_add_n(m, m, n, wsize);
+ m[LIMB_SIZE_25519] += cy;
+
+ cy = mpihelp_add_n(wp, wp, m, wsize);
+ m[LIMB_SIZE_25519] += cy;
+
+ memset(m, 0, wsize * BYTES_PER_MPI_LIMB);
+ msb = (wp[LIMB_SIZE_25519-1] >> (255 % BITS_PER_MPI_LIMB));
+ m[0] = (m[LIMB_SIZE_25519] * 2 + msb) * 19;
+ wp[LIMB_SIZE_25519-1] &= ~((mpi_limb_t)1 << (255 % BITS_PER_MPI_LIMB));
+ mpihelp_add_n(wp, wp, m, wsize);
+
+ m[0] = 0;
+ cy = mpihelp_sub_n(wp, wp, ctx->p->d, wsize);
+ mpih_set_cond(m, ctx->p->d, wsize, (cy != 0UL));
+ mpihelp_add_n(wp, wp, m, wsize);
+}
+
+static void ec_mul2_25519(MPI w, MPI u, struct mpi_ec_ctx *ctx)
+{
+ ec_addm_25519(w, u, u, ctx);
+}
+
+static void ec_pow2_25519(MPI w, const MPI b, struct mpi_ec_ctx *ctx)
+{
+ ec_mulm_25519(w, b, b, ctx);
+}
+
+/* Routines for 2^448 - 2^224 - 1. */
+
+#define LIMB_SIZE_448 ((448+BITS_PER_MPI_LIMB-1)/BITS_PER_MPI_LIMB)
+#define LIMB_SIZE_HALF_448 ((LIMB_SIZE_448+1)/2)
+
+static void ec_addm_448(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx)
+{
+ mpi_ptr_t wp, up, vp;
+ mpi_size_t wsize = LIMB_SIZE_448;
+ mpi_limb_t n[LIMB_SIZE_448];
+ mpi_limb_t cy;
+
+ if (w->nlimbs != wsize || u->nlimbs != wsize || v->nlimbs != wsize)
+ log_bug("addm_448: different sizes\n");
+
+ memset(n, 0, sizeof(n));
+ up = u->d;
+ vp = v->d;
+ wp = w->d;
+
+ cy = mpihelp_add_n(wp, up, vp, wsize);
+ mpih_set_cond(n, ctx->p->d, wsize, (cy != 0UL));
+ mpihelp_sub_n(wp, wp, n, wsize);
+}
+
+static void ec_subm_448(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx)
+{
+ mpi_ptr_t wp, up, vp;
+ mpi_size_t wsize = LIMB_SIZE_448;
+ mpi_limb_t n[LIMB_SIZE_448];
+ mpi_limb_t borrow;
+
+ if (w->nlimbs != wsize || u->nlimbs != wsize || v->nlimbs != wsize)
+ log_bug("subm_448: different sizes\n");
+
+ memset(n, 0, sizeof(n));
+ up = u->d;
+ vp = v->d;
+ wp = w->d;
+
+ borrow = mpihelp_sub_n(wp, up, vp, wsize);
+ mpih_set_cond(n, ctx->p->d, wsize, (borrow != 0UL));
+ mpihelp_add_n(wp, wp, n, wsize);
+}
+
+static void ec_mulm_448(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx)
+{
+ mpi_ptr_t wp, up, vp;
+ mpi_size_t wsize = LIMB_SIZE_448;
+ mpi_limb_t n[LIMB_SIZE_448*2];
+ mpi_limb_t a2[LIMB_SIZE_HALF_448];
+ mpi_limb_t a3[LIMB_SIZE_HALF_448];
+ mpi_limb_t b0[LIMB_SIZE_HALF_448];
+ mpi_limb_t b1[LIMB_SIZE_HALF_448];
+ mpi_limb_t cy;
+ int i;
+#if (LIMB_SIZE_HALF_448 > LIMB_SIZE_448/2)
+ mpi_limb_t b1_rest, a3_rest;
+#endif
+
+ if (w->nlimbs != wsize || u->nlimbs != wsize || v->nlimbs != wsize)
+ log_bug("mulm_448: different sizes\n");
+
+ up = u->d;
+ vp = v->d;
+ wp = w->d;
+
+ mpihelp_mul_n(n, up, vp, wsize);
+
+ for (i = 0; i < (wsize + 1) / 2; i++) {
+ b0[i] = n[i];
+ b1[i] = n[i+wsize/2];
+ a2[i] = n[i+wsize];
+ a3[i] = n[i+wsize+wsize/2];
+ }
+
+#if (LIMB_SIZE_HALF_448 > LIMB_SIZE_448/2)
+ b0[LIMB_SIZE_HALF_448-1] &= ((mpi_limb_t)1UL << 32)-1;
+ a2[LIMB_SIZE_HALF_448-1] &= ((mpi_limb_t)1UL << 32)-1;
+
+ b1_rest = 0;
+ a3_rest = 0;
+
+ for (i = (wsize + 1) / 2 - 1; i >= 0; i--) {
+ mpi_limb_t b1v, a3v;
+ b1v = b1[i];
+ a3v = a3[i];
+ b1[i] = (b1_rest << 32) | (b1v >> 32);
+ a3[i] = (a3_rest << 32) | (a3v >> 32);
+ b1_rest = b1v & (((mpi_limb_t)1UL << 32)-1);
+ a3_rest = a3v & (((mpi_limb_t)1UL << 32)-1);
+ }
+#endif
+
+ cy = mpihelp_add_n(b0, b0, a2, LIMB_SIZE_HALF_448);
+ cy += mpihelp_add_n(b0, b0, a3, LIMB_SIZE_HALF_448);
+ for (i = 0; i < (wsize + 1) / 2; i++)
+ wp[i] = b0[i];
+#if (LIMB_SIZE_HALF_448 > LIMB_SIZE_448/2)
+ wp[LIMB_SIZE_HALF_448-1] &= (((mpi_limb_t)1UL << 32)-1);
+#endif
+
+#if (LIMB_SIZE_HALF_448 > LIMB_SIZE_448/2)
+ cy = b0[LIMB_SIZE_HALF_448-1] >> 32;
+#endif
+
+ cy = mpihelp_add_1(b1, b1, LIMB_SIZE_HALF_448, cy);
+ cy += mpihelp_add_n(b1, b1, a2, LIMB_SIZE_HALF_448);
+ cy += mpihelp_add_n(b1, b1, a3, LIMB_SIZE_HALF_448);
+ cy += mpihelp_add_n(b1, b1, a3, LIMB_SIZE_HALF_448);
+#if (LIMB_SIZE_HALF_448 > LIMB_SIZE_448/2)
+ b1_rest = 0;
+ for (i = (wsize + 1) / 2 - 1; i >= 0; i--) {
+ mpi_limb_t b1v = b1[i];
+ b1[i] = (b1_rest << 32) | (b1v >> 32);
+ b1_rest = b1v & (((mpi_limb_t)1UL << 32)-1);
+ }
+ wp[LIMB_SIZE_HALF_448-1] |= (b1_rest << 32);
+#endif
+ for (i = 0; i < wsize / 2; i++)
+ wp[i+(wsize + 1) / 2] = b1[i];
+
+#if (LIMB_SIZE_HALF_448 > LIMB_SIZE_448/2)
+ cy = b1[LIMB_SIZE_HALF_448-1];
+#endif
+
+ memset(n, 0, wsize * BYTES_PER_MPI_LIMB);
+
+#if (LIMB_SIZE_HALF_448 > LIMB_SIZE_448/2)
+ n[LIMB_SIZE_HALF_448-1] = cy << 32;
+#else
+ n[LIMB_SIZE_HALF_448] = cy;
+#endif
+ n[0] = cy;
+ mpihelp_add_n(wp, wp, n, wsize);
+
+ memset(n, 0, wsize * BYTES_PER_MPI_LIMB);
+ cy = mpihelp_sub_n(wp, wp, ctx->p->d, wsize);
+ mpih_set_cond(n, ctx->p->d, wsize, (cy != 0UL));
+ mpihelp_add_n(wp, wp, n, wsize);
+}
+
+static void ec_mul2_448(MPI w, MPI u, struct mpi_ec_ctx *ctx)
+{
+ ec_addm_448(w, u, u, ctx);
+}
+
+static void ec_pow2_448(MPI w, const MPI b, struct mpi_ec_ctx *ctx)
+{
+ ec_mulm_448(w, b, b, ctx);
+}
+
+struct field_table {
+ const char *p;
+
+ /* computation routines for the field. */
+ void (*addm)(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx);
+ void (*subm)(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx);
+ void (*mulm)(MPI w, MPI u, MPI v, struct mpi_ec_ctx *ctx);
+ void (*mul2)(MPI w, MPI u, struct mpi_ec_ctx *ctx);
+ void (*pow2)(MPI w, const MPI b, struct mpi_ec_ctx *ctx);
+};
+
+static const struct field_table field_table[] = {
+ {
+ "0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFED",
+ ec_addm_25519,
+ ec_subm_25519,
+ ec_mulm_25519,
+ ec_mul2_25519,
+ ec_pow2_25519
+ },
+ {
+ "0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE"
+ "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF",
+ ec_addm_448,
+ ec_subm_448,
+ ec_mulm_448,
+ ec_mul2_448,
+ ec_pow2_448
+ },
+ { NULL, NULL, NULL, NULL, NULL, NULL },
+};
+
+/* Force recomputation of all helper variables. */
+static void mpi_ec_get_reset(struct mpi_ec_ctx *ec)
+{
+ ec->t.valid.a_is_pminus3 = 0;
+ ec->t.valid.two_inv_p = 0;
+}
+
+/* Accessor for helper variable. */
+static int ec_get_a_is_pminus3(struct mpi_ec_ctx *ec)
+{
+ MPI tmp;
+
+ if (!ec->t.valid.a_is_pminus3) {
+ ec->t.valid.a_is_pminus3 = 1;
+ tmp = mpi_alloc_like(ec->p);
+ mpi_sub_ui(tmp, ec->p, 3);
+ ec->t.a_is_pminus3 = !mpi_cmp(ec->a, tmp);
+ mpi_free(tmp);
+ }
+
+ return ec->t.a_is_pminus3;
+}
+
+/* Accessor for helper variable. */
+static MPI ec_get_two_inv_p(struct mpi_ec_ctx *ec)
+{
+ if (!ec->t.valid.two_inv_p) {
+ ec->t.valid.two_inv_p = 1;
+ if (!ec->t.two_inv_p)
+ ec->t.two_inv_p = mpi_alloc(0);
+ ec_invm(ec->t.two_inv_p, mpi_const(MPI_C_TWO), ec);
+ }
+ return ec->t.two_inv_p;
+}
+
+static const char *const curve25519_bad_points[] = {
+ "0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed",
+ "0x0000000000000000000000000000000000000000000000000000000000000000",
+ "0x0000000000000000000000000000000000000000000000000000000000000001",
+ "0x00b8495f16056286fdb1329ceb8d09da6ac49ff1fae35616aeb8413b7c7aebe0",
+ "0x57119fd0dd4e22d8868e1c58c45c44045bef839c55b1d0b1248c50a3bc959c5f",
+ "0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffec",
+ "0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffee",
+ NULL
+};
+
+static const char *const curve448_bad_points[] = {
+ "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffe"
+ "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
+ "0x00000000000000000000000000000000000000000000000000000000"
+ "00000000000000000000000000000000000000000000000000000000",
+ "0x00000000000000000000000000000000000000000000000000000000"
+ "00000000000000000000000000000000000000000000000000000001",
+ "0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffe"
+ "fffffffffffffffffffffffffffffffffffffffffffffffffffffffe",
+ "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+ "00000000000000000000000000000000000000000000000000000000",
+ NULL
+};
+
+static const char *const *bad_points_table[] = {
+ curve25519_bad_points,
+ curve448_bad_points,
+};
+
+static void mpi_ec_coefficient_normalize(MPI a, MPI p)
+{
+ if (a->sign) {
+ mpi_resize(a, p->nlimbs);
+ mpihelp_sub_n(a->d, p->d, a->d, p->nlimbs);
+ a->nlimbs = p->nlimbs;
+ a->sign = 0;
+ }
+}
+
+/* This function initialized a context for elliptic curve based on the
+ * field GF(p). P is the prime specifying this field, A is the first
+ * coefficient. CTX is expected to be zeroized.
+ */
+void mpi_ec_init(struct mpi_ec_ctx *ctx, enum gcry_mpi_ec_models model,
+ enum ecc_dialects dialect,
+ int flags, MPI p, MPI a, MPI b)
+{
+ int i;
+ static int use_barrett = -1 /* TODO: 1 or -1 */;
+
+ mpi_ec_coefficient_normalize(a, p);
+ mpi_ec_coefficient_normalize(b, p);
+
+ /* Fixme: Do we want to check some constraints? e.g. a < p */
+
+ ctx->model = model;
+ ctx->dialect = dialect;
+ ctx->flags = flags;
+ if (dialect == ECC_DIALECT_ED25519)
+ ctx->nbits = 256;
+ else
+ ctx->nbits = mpi_get_nbits(p);
+ ctx->p = mpi_copy(p);
+ ctx->a = mpi_copy(a);
+ ctx->b = mpi_copy(b);
+
+ ctx->t.p_barrett = use_barrett > 0 ? mpi_barrett_init(ctx->p, 0) : NULL;
+
+ mpi_ec_get_reset(ctx);
+
+ if (model == MPI_EC_MONTGOMERY) {
+ for (i = 0; i < DIM(bad_points_table); i++) {
+ MPI p_candidate = mpi_scanval(bad_points_table[i][0]);
+ int match_p = !mpi_cmp(ctx->p, p_candidate);
+ int j;
+
+ mpi_free(p_candidate);
+ if (!match_p)
+ continue;
+
+ for (j = 0; i < DIM(ctx->t.scratch) && bad_points_table[i][j]; j++)
+ ctx->t.scratch[j] = mpi_scanval(bad_points_table[i][j]);
+ }
+ } else {
+ /* Allocate scratch variables. */
+ for (i = 0; i < DIM(ctx->t.scratch); i++)
+ ctx->t.scratch[i] = mpi_alloc_like(ctx->p);
+ }
+
+ ctx->addm = ec_addm;
+ ctx->subm = ec_subm;
+ ctx->mulm = ec_mulm;
+ ctx->mul2 = ec_mul2;
+ ctx->pow2 = ec_pow2;
+
+ for (i = 0; field_table[i].p; i++) {
+ MPI f_p;
+
+ f_p = mpi_scanval(field_table[i].p);
+ if (!f_p)
+ break;
+
+ if (!mpi_cmp(p, f_p)) {
+ ctx->addm = field_table[i].addm;
+ ctx->subm = field_table[i].subm;
+ ctx->mulm = field_table[i].mulm;
+ ctx->mul2 = field_table[i].mul2;
+ ctx->pow2 = field_table[i].pow2;
+ mpi_free(f_p);
+
+ mpi_resize(ctx->a, ctx->p->nlimbs);
+ ctx->a->nlimbs = ctx->p->nlimbs;
+
+ mpi_resize(ctx->b, ctx->p->nlimbs);
+ ctx->b->nlimbs = ctx->p->nlimbs;
+
+ for (i = 0; i < DIM(ctx->t.scratch) && ctx->t.scratch[i]; i++)
+ ctx->t.scratch[i]->nlimbs = ctx->p->nlimbs;
+
+ break;
+ }
+
+ mpi_free(f_p);
+ }
+}
+EXPORT_SYMBOL_GPL(mpi_ec_init);
+
+void mpi_ec_deinit(struct mpi_ec_ctx *ctx)
+{
+ int i;
+
+ mpi_barrett_free(ctx->t.p_barrett);
+
+ /* Domain parameter. */
+ mpi_free(ctx->p);
+ mpi_free(ctx->a);
+ mpi_free(ctx->b);
+ mpi_point_release(ctx->G);
+ mpi_free(ctx->n);
+
+ /* The key. */
+ mpi_point_release(ctx->Q);
+ mpi_free(ctx->d);
+
+ /* Private data of ec.c. */
+ mpi_free(ctx->t.two_inv_p);
+
+ for (i = 0; i < DIM(ctx->t.scratch); i++)
+ mpi_free(ctx->t.scratch[i]);
+}
+EXPORT_SYMBOL_GPL(mpi_ec_deinit);
+
+/* Compute the affine coordinates from the projective coordinates in
+ * POINT. Set them into X and Y. If one coordinate is not required,
+ * X or Y may be passed as NULL. CTX is the usual context. Returns: 0
+ * on success or !0 if POINT is at infinity.
+ */
+int mpi_ec_get_affine(MPI x, MPI y, MPI_POINT point, struct mpi_ec_ctx *ctx)
+{
+ if (!mpi_cmp_ui(point->z, 0))
+ return -1;
+
+ switch (ctx->model) {
+ case MPI_EC_WEIERSTRASS: /* Using Jacobian coordinates. */
+ {
+ MPI z1, z2, z3;
+
+ z1 = mpi_new(0);
+ z2 = mpi_new(0);
+ ec_invm(z1, point->z, ctx); /* z1 = z^(-1) mod p */
+ ec_mulm(z2, z1, z1, ctx); /* z2 = z^(-2) mod p */
+
+ if (x)
+ ec_mulm(x, point->x, z2, ctx);
+
+ if (y) {
+ z3 = mpi_new(0);
+ ec_mulm(z3, z2, z1, ctx); /* z3 = z^(-3) mod p */
+ ec_mulm(y, point->y, z3, ctx);
+ mpi_free(z3);
+ }
+
+ mpi_free(z2);
+ mpi_free(z1);
+ }
+ return 0;
+
+ case MPI_EC_MONTGOMERY:
+ {
+ if (x)
+ mpi_set(x, point->x);
+
+ if (y) {
+ log_fatal("%s: Getting Y-coordinate on %s is not supported\n",
+ "mpi_ec_get_affine", "Montgomery");
+ return -1;
+ }
+ }
+ return 0;
+
+ case MPI_EC_EDWARDS:
+ {
+ MPI z;
+
+ z = mpi_new(0);
+ ec_invm(z, point->z, ctx);
+
+ mpi_resize(z, ctx->p->nlimbs);
+ z->nlimbs = ctx->p->nlimbs;
+
+ if (x) {
+ mpi_resize(x, ctx->p->nlimbs);
+ x->nlimbs = ctx->p->nlimbs;
+ ctx->mulm(x, point->x, z, ctx);
+ }
+ if (y) {
+ mpi_resize(y, ctx->p->nlimbs);
+ y->nlimbs = ctx->p->nlimbs;
+ ctx->mulm(y, point->y, z, ctx);
+ }
+
+ mpi_free(z);
+ }
+ return 0;
+
+ default:
+ return -1;
+ }
+}
+EXPORT_SYMBOL_GPL(mpi_ec_get_affine);
+
+/* RESULT = 2 * POINT (Weierstrass version). */
+static void dup_point_weierstrass(MPI_POINT result,
+ MPI_POINT point, struct mpi_ec_ctx *ctx)
+{
+#define x3 (result->x)
+#define y3 (result->y)
+#define z3 (result->z)
+#define t1 (ctx->t.scratch[0])
+#define t2 (ctx->t.scratch[1])
+#define t3 (ctx->t.scratch[2])
+#define l1 (ctx->t.scratch[3])
+#define l2 (ctx->t.scratch[4])
+#define l3 (ctx->t.scratch[5])
+
+ if (!mpi_cmp_ui(point->y, 0) || !mpi_cmp_ui(point->z, 0)) {
+ /* P_y == 0 || P_z == 0 => [1:1:0] */
+ mpi_set_ui(x3, 1);
+ mpi_set_ui(y3, 1);
+ mpi_set_ui(z3, 0);
+ } else {
+ if (ec_get_a_is_pminus3(ctx)) {
+ /* Use the faster case. */
+ /* L1 = 3(X - Z^2)(X + Z^2) */
+ /* T1: used for Z^2. */
+ /* T2: used for the right term. */
+ ec_pow2(t1, point->z, ctx);
+ ec_subm(l1, point->x, t1, ctx);
+ ec_mulm(l1, l1, mpi_const(MPI_C_THREE), ctx);
+ ec_addm(t2, point->x, t1, ctx);
+ ec_mulm(l1, l1, t2, ctx);
+ } else {
+ /* Standard case. */
+ /* L1 = 3X^2 + aZ^4 */
+ /* T1: used for aZ^4. */
+ ec_pow2(l1, point->x, ctx);
+ ec_mulm(l1, l1, mpi_const(MPI_C_THREE), ctx);
+ ec_powm(t1, point->z, mpi_const(MPI_C_FOUR), ctx);
+ ec_mulm(t1, t1, ctx->a, ctx);
+ ec_addm(l1, l1, t1, ctx);
+ }
+ /* Z3 = 2YZ */
+ ec_mulm(z3, point->y, point->z, ctx);
+ ec_mul2(z3, z3, ctx);
+
+ /* L2 = 4XY^2 */
+ /* T2: used for Y2; required later. */
+ ec_pow2(t2, point->y, ctx);
+ ec_mulm(l2, t2, point->x, ctx);
+ ec_mulm(l2, l2, mpi_const(MPI_C_FOUR), ctx);
+
+ /* X3 = L1^2 - 2L2 */
+ /* T1: used for L2^2. */
+ ec_pow2(x3, l1, ctx);
+ ec_mul2(t1, l2, ctx);
+ ec_subm(x3, x3, t1, ctx);
+
+ /* L3 = 8Y^4 */
+ /* T2: taken from above. */
+ ec_pow2(t2, t2, ctx);
+ ec_mulm(l3, t2, mpi_const(MPI_C_EIGHT), ctx);
+
+ /* Y3 = L1(L2 - X3) - L3 */
+ ec_subm(y3, l2, x3, ctx);
+ ec_mulm(y3, y3, l1, ctx);
+ ec_subm(y3, y3, l3, ctx);
+ }
+
+#undef x3
+#undef y3
+#undef z3
+#undef t1
+#undef t2
+#undef t3
+#undef l1
+#undef l2
+#undef l3
+}
+
+/* RESULT = 2 * POINT (Montgomery version). */
+static void dup_point_montgomery(MPI_POINT result,
+ MPI_POINT point, struct mpi_ec_ctx *ctx)
+{
+ (void)result;
+ (void)point;
+ (void)ctx;
+ log_fatal("%s: %s not yet supported\n",
+ "mpi_ec_dup_point", "Montgomery");
+}
+
+/* RESULT = 2 * POINT (Twisted Edwards version). */
+static void dup_point_edwards(MPI_POINT result,
+ MPI_POINT point, struct mpi_ec_ctx *ctx)
+{
+#define X1 (point->x)
+#define Y1 (point->y)
+#define Z1 (point->z)
+#define X3 (result->x)
+#define Y3 (result->y)
+#define Z3 (result->z)
+#define B (ctx->t.scratch[0])
+#define C (ctx->t.scratch[1])
+#define D (ctx->t.scratch[2])
+#define E (ctx->t.scratch[3])
+#define F (ctx->t.scratch[4])
+#define H (ctx->t.scratch[5])
+#define J (ctx->t.scratch[6])
+
+ /* Compute: (X_3 : Y_3 : Z_3) = 2( X_1 : Y_1 : Z_1 ) */
+
+ /* B = (X_1 + Y_1)^2 */
+ ctx->addm(B, X1, Y1, ctx);
+ ctx->pow2(B, B, ctx);
+
+ /* C = X_1^2 */
+ /* D = Y_1^2 */
+ ctx->pow2(C, X1, ctx);
+ ctx->pow2(D, Y1, ctx);
+
+ /* E = aC */
+ if (ctx->dialect == ECC_DIALECT_ED25519)
+ ctx->subm(E, ctx->p, C, ctx);
+ else
+ ctx->mulm(E, ctx->a, C, ctx);
+
+ /* F = E + D */
+ ctx->addm(F, E, D, ctx);
+
+ /* H = Z_1^2 */
+ ctx->pow2(H, Z1, ctx);
+
+ /* J = F - 2H */
+ ctx->mul2(J, H, ctx);
+ ctx->subm(J, F, J, ctx);
+
+ /* X_3 = (B - C - D) · J */
+ ctx->subm(X3, B, C, ctx);
+ ctx->subm(X3, X3, D, ctx);
+ ctx->mulm(X3, X3, J, ctx);
+
+ /* Y_3 = F · (E - D) */
+ ctx->subm(Y3, E, D, ctx);
+ ctx->mulm(Y3, Y3, F, ctx);
+
+ /* Z_3 = F · J */
+ ctx->mulm(Z3, F, J, ctx);
+
+#undef X1
+#undef Y1
+#undef Z1
+#undef X3
+#undef Y3
+#undef Z3
+#undef B
+#undef C
+#undef D
+#undef E
+#undef F
+#undef H
+#undef J
+}
+
+/* RESULT = 2 * POINT */
+static void
+mpi_ec_dup_point(MPI_POINT result, MPI_POINT point, struct mpi_ec_ctx *ctx)
+{
+ switch (ctx->model) {
+ case MPI_EC_WEIERSTRASS:
+ dup_point_weierstrass(result, point, ctx);
+ break;
+ case MPI_EC_MONTGOMERY:
+ dup_point_montgomery(result, point, ctx);
+ break;
+ case MPI_EC_EDWARDS:
+ dup_point_edwards(result, point, ctx);
+ break;
+ }
+}
+
+/* RESULT = P1 + P2 (Weierstrass version).*/
+static void add_points_weierstrass(MPI_POINT result,
+ MPI_POINT p1, MPI_POINT p2,
+ struct mpi_ec_ctx *ctx)
+{
+#define x1 (p1->x)
+#define y1 (p1->y)
+#define z1 (p1->z)
+#define x2 (p2->x)
+#define y2 (p2->y)
+#define z2 (p2->z)
+#define x3 (result->x)
+#define y3 (result->y)
+#define z3 (result->z)
+#define l1 (ctx->t.scratch[0])
+#define l2 (ctx->t.scratch[1])
+#define l3 (ctx->t.scratch[2])
+#define l4 (ctx->t.scratch[3])
+#define l5 (ctx->t.scratch[4])
+#define l6 (ctx->t.scratch[5])
+#define l7 (ctx->t.scratch[6])
+#define l8 (ctx->t.scratch[7])
+#define l9 (ctx->t.scratch[8])
+#define t1 (ctx->t.scratch[9])
+#define t2 (ctx->t.scratch[10])
+
+ if ((!mpi_cmp(x1, x2)) && (!mpi_cmp(y1, y2)) && (!mpi_cmp(z1, z2))) {
+ /* Same point; need to call the duplicate function. */
+ mpi_ec_dup_point(result, p1, ctx);
+ } else if (!mpi_cmp_ui(z1, 0)) {
+ /* P1 is at infinity. */
+ mpi_set(x3, p2->x);
+ mpi_set(y3, p2->y);
+ mpi_set(z3, p2->z);
+ } else if (!mpi_cmp_ui(z2, 0)) {
+ /* P2 is at infinity. */
+ mpi_set(x3, p1->x);
+ mpi_set(y3, p1->y);
+ mpi_set(z3, p1->z);
+ } else {
+ int z1_is_one = !mpi_cmp_ui(z1, 1);
+ int z2_is_one = !mpi_cmp_ui(z2, 1);
+
+ /* l1 = x1 z2^2 */
+ /* l2 = x2 z1^2 */
+ if (z2_is_one)
+ mpi_set(l1, x1);
+ else {
+ ec_pow2(l1, z2, ctx);
+ ec_mulm(l1, l1, x1, ctx);
+ }
+ if (z1_is_one)
+ mpi_set(l2, x2);
+ else {
+ ec_pow2(l2, z1, ctx);
+ ec_mulm(l2, l2, x2, ctx);
+ }
+ /* l3 = l1 - l2 */
+ ec_subm(l3, l1, l2, ctx);
+ /* l4 = y1 z2^3 */
+ ec_powm(l4, z2, mpi_const(MPI_C_THREE), ctx);
+ ec_mulm(l4, l4, y1, ctx);
+ /* l5 = y2 z1^3 */
+ ec_powm(l5, z1, mpi_const(MPI_C_THREE), ctx);
+ ec_mulm(l5, l5, y2, ctx);
+ /* l6 = l4 - l5 */
+ ec_subm(l6, l4, l5, ctx);
+
+ if (!mpi_cmp_ui(l3, 0)) {
+ if (!mpi_cmp_ui(l6, 0)) {
+ /* P1 and P2 are the same - use duplicate function. */
+ mpi_ec_dup_point(result, p1, ctx);
+ } else {
+ /* P1 is the inverse of P2. */
+ mpi_set_ui(x3, 1);
+ mpi_set_ui(y3, 1);
+ mpi_set_ui(z3, 0);
+ }
+ } else {
+ /* l7 = l1 + l2 */
+ ec_addm(l7, l1, l2, ctx);
+ /* l8 = l4 + l5 */
+ ec_addm(l8, l4, l5, ctx);
+ /* z3 = z1 z2 l3 */
+ ec_mulm(z3, z1, z2, ctx);
+ ec_mulm(z3, z3, l3, ctx);
+ /* x3 = l6^2 - l7 l3^2 */
+ ec_pow2(t1, l6, ctx);
+ ec_pow2(t2, l3, ctx);
+ ec_mulm(t2, t2, l7, ctx);
+ ec_subm(x3, t1, t2, ctx);
+ /* l9 = l7 l3^2 - 2 x3 */
+ ec_mul2(t1, x3, ctx);
+ ec_subm(l9, t2, t1, ctx);
+ /* y3 = (l9 l6 - l8 l3^3)/2 */
+ ec_mulm(l9, l9, l6, ctx);
+ ec_powm(t1, l3, mpi_const(MPI_C_THREE), ctx); /* fixme: Use saved value*/
+ ec_mulm(t1, t1, l8, ctx);
+ ec_subm(y3, l9, t1, ctx);
+ ec_mulm(y3, y3, ec_get_two_inv_p(ctx), ctx);
+ }
+ }
+
+#undef x1
+#undef y1
+#undef z1
+#undef x2
+#undef y2
+#undef z2
+#undef x3
+#undef y3
+#undef z3
+#undef l1
+#undef l2
+#undef l3
+#undef l4
+#undef l5
+#undef l6
+#undef l7
+#undef l8
+#undef l9
+#undef t1
+#undef t2
+}
+
+/* RESULT = P1 + P2 (Montgomery version).*/
+static void add_points_montgomery(MPI_POINT result,
+ MPI_POINT p1, MPI_POINT p2,
+ struct mpi_ec_ctx *ctx)
+{
+ (void)result;
+ (void)p1;
+ (void)p2;
+ (void)ctx;
+ log_fatal("%s: %s not yet supported\n",
+ "mpi_ec_add_points", "Montgomery");
+}
+
+/* RESULT = P1 + P2 (Twisted Edwards version).*/
+static void add_points_edwards(MPI_POINT result,
+ MPI_POINT p1, MPI_POINT p2,
+ struct mpi_ec_ctx *ctx)
+{
+#define X1 (p1->x)
+#define Y1 (p1->y)
+#define Z1 (p1->z)
+#define X2 (p2->x)
+#define Y2 (p2->y)
+#define Z2 (p2->z)
+#define X3 (result->x)
+#define Y3 (result->y)
+#define Z3 (result->z)
+#define A (ctx->t.scratch[0])
+#define B (ctx->t.scratch[1])
+#define C (ctx->t.scratch[2])
+#define D (ctx->t.scratch[3])
+#define E (ctx->t.scratch[4])
+#define F (ctx->t.scratch[5])
+#define G (ctx->t.scratch[6])
+#define tmp (ctx->t.scratch[7])
+
+ point_resize(result, ctx);
+
+ /* Compute: (X_3 : Y_3 : Z_3) = (X_1 : Y_1 : Z_1) + (X_2 : Y_2 : Z_3) */
+
+ /* A = Z1 · Z2 */
+ ctx->mulm(A, Z1, Z2, ctx);
+
+ /* B = A^2 */
+ ctx->pow2(B, A, ctx);
+
+ /* C = X1 · X2 */
+ ctx->mulm(C, X1, X2, ctx);
+
+ /* D = Y1 · Y2 */
+ ctx->mulm(D, Y1, Y2, ctx);
+
+ /* E = d · C · D */
+ ctx->mulm(E, ctx->b, C, ctx);
+ ctx->mulm(E, E, D, ctx);
+
+ /* F = B - E */
+ ctx->subm(F, B, E, ctx);
+
+ /* G = B + E */
+ ctx->addm(G, B, E, ctx);
+
+ /* X_3 = A · F · ((X_1 + Y_1) · (X_2 + Y_2) - C - D) */
+ ctx->addm(tmp, X1, Y1, ctx);
+ ctx->addm(X3, X2, Y2, ctx);
+ ctx->mulm(X3, X3, tmp, ctx);
+ ctx->subm(X3, X3, C, ctx);
+ ctx->subm(X3, X3, D, ctx);
+ ctx->mulm(X3, X3, F, ctx);
+ ctx->mulm(X3, X3, A, ctx);
+
+ /* Y_3 = A · G · (D - aC) */
+ if (ctx->dialect == ECC_DIALECT_ED25519) {
+ ctx->addm(Y3, D, C, ctx);
+ } else {
+ ctx->mulm(Y3, ctx->a, C, ctx);
+ ctx->subm(Y3, D, Y3, ctx);
+ }
+ ctx->mulm(Y3, Y3, G, ctx);
+ ctx->mulm(Y3, Y3, A, ctx);
+
+ /* Z_3 = F · G */
+ ctx->mulm(Z3, F, G, ctx);
+
+
+#undef X1
+#undef Y1
+#undef Z1
+#undef X2
+#undef Y2
+#undef Z2
+#undef X3
+#undef Y3
+#undef Z3
+#undef A
+#undef B
+#undef C
+#undef D
+#undef E
+#undef F
+#undef G
+#undef tmp
+}
+
+/* Compute a step of Montgomery Ladder (only use X and Z in the point).
+ * Inputs: P1, P2, and x-coordinate of DIF = P1 - P1.
+ * Outputs: PRD = 2 * P1 and SUM = P1 + P2.
+ */
+static void montgomery_ladder(MPI_POINT prd, MPI_POINT sum,
+ MPI_POINT p1, MPI_POINT p2, MPI dif_x,
+ struct mpi_ec_ctx *ctx)
+{
+ ctx->addm(sum->x, p2->x, p2->z, ctx);
+ ctx->subm(p2->z, p2->x, p2->z, ctx);
+ ctx->addm(prd->x, p1->x, p1->z, ctx);
+ ctx->subm(p1->z, p1->x, p1->z, ctx);
+ ctx->mulm(p2->x, p1->z, sum->x, ctx);
+ ctx->mulm(p2->z, prd->x, p2->z, ctx);
+ ctx->pow2(p1->x, prd->x, ctx);
+ ctx->pow2(p1->z, p1->z, ctx);
+ ctx->addm(sum->x, p2->x, p2->z, ctx);
+ ctx->subm(p2->z, p2->x, p2->z, ctx);
+ ctx->mulm(prd->x, p1->x, p1->z, ctx);
+ ctx->subm(p1->z, p1->x, p1->z, ctx);
+ ctx->pow2(sum->x, sum->x, ctx);
+ ctx->pow2(sum->z, p2->z, ctx);
+ ctx->mulm(prd->z, p1->z, ctx->a, ctx); /* CTX->A: (a-2)/4 */
+ ctx->mulm(sum->z, sum->z, dif_x, ctx);
+ ctx->addm(prd->z, p1->x, prd->z, ctx);
+ ctx->mulm(prd->z, prd->z, p1->z, ctx);
+}
+
+/* RESULT = P1 + P2 */
+void mpi_ec_add_points(MPI_POINT result,
+ MPI_POINT p1, MPI_POINT p2,
+ struct mpi_ec_ctx *ctx)
+{
+ switch (ctx->model) {
+ case MPI_EC_WEIERSTRASS:
+ add_points_weierstrass(result, p1, p2, ctx);
+ break;
+ case MPI_EC_MONTGOMERY:
+ add_points_montgomery(result, p1, p2, ctx);
+ break;
+ case MPI_EC_EDWARDS:
+ add_points_edwards(result, p1, p2, ctx);
+ break;
+ }
+}
+EXPORT_SYMBOL_GPL(mpi_ec_add_points);
+
+/* Scalar point multiplication - the main function for ECC. If takes
+ * an integer SCALAR and a POINT as well as the usual context CTX.
+ * RESULT will be set to the resulting point.
+ */
+void mpi_ec_mul_point(MPI_POINT result,
+ MPI scalar, MPI_POINT point,
+ struct mpi_ec_ctx *ctx)
+{
+ MPI x1, y1, z1, k, h, yy;
+ unsigned int i, loops;
+ struct gcry_mpi_point p1, p2, p1inv;
+
+ if (ctx->model == MPI_EC_EDWARDS) {
+ /* Simple left to right binary method. Algorithm 3.27 from
+ * {author={Hankerson, Darrel and Menezes, Alfred J. and Vanstone, Scott},
+ * title = {Guide to Elliptic Curve Cryptography},
+ * year = {2003}, isbn = {038795273X},
+ * url = {http://www.cacr.math.uwaterloo.ca/ecc/},
+ * publisher = {Springer-Verlag New York, Inc.}}
+ */
+ unsigned int nbits;
+ int j;
+
+ if (mpi_cmp(scalar, ctx->p) >= 0)
+ nbits = mpi_get_nbits(scalar);
+ else
+ nbits = mpi_get_nbits(ctx->p);
+
+ mpi_set_ui(result->x, 0);
+ mpi_set_ui(result->y, 1);
+ mpi_set_ui(result->z, 1);
+ point_resize(point, ctx);
+
+ point_resize(result, ctx);
+ point_resize(point, ctx);
+
+ for (j = nbits-1; j >= 0; j--) {
+ mpi_ec_dup_point(result, result, ctx);
+ if (mpi_test_bit(scalar, j))
+ mpi_ec_add_points(result, result, point, ctx);
+ }
+ return;
+ } else if (ctx->model == MPI_EC_MONTGOMERY) {
+ unsigned int nbits;
+ int j;
+ struct gcry_mpi_point p1_, p2_;
+ MPI_POINT q1, q2, prd, sum;
+ unsigned long sw;
+ mpi_size_t rsize;
+ int scalar_copied = 0;
+
+ /* Compute scalar point multiplication with Montgomery Ladder.
+ * Note that we don't use Y-coordinate in the points at all.
+ * RESULT->Y will be filled by zero.
+ */
+
+ nbits = mpi_get_nbits(scalar);
+ point_init(&p1);
+ point_init(&p2);
+ point_init(&p1_);
+ point_init(&p2_);
+ mpi_set_ui(p1.x, 1);
+ mpi_free(p2.x);
+ p2.x = mpi_copy(point->x);
+ mpi_set_ui(p2.z, 1);
+
+ point_resize(&p1, ctx);
+ point_resize(&p2, ctx);
+ point_resize(&p1_, ctx);
+ point_resize(&p2_, ctx);
+
+ mpi_resize(point->x, ctx->p->nlimbs);
+ point->x->nlimbs = ctx->p->nlimbs;
+
+ q1 = &p1;
+ q2 = &p2;
+ prd = &p1_;
+ sum = &p2_;
+
+ for (j = nbits-1; j >= 0; j--) {
+ MPI_POINT t;
+
+ sw = mpi_test_bit(scalar, j);
+ point_swap_cond(q1, q2, sw, ctx);
+ montgomery_ladder(prd, sum, q1, q2, point->x, ctx);
+ point_swap_cond(prd, sum, sw, ctx);
+ t = q1; q1 = prd; prd = t;
+ t = q2; q2 = sum; sum = t;
+ }
+
+ mpi_clear(result->y);
+ sw = (nbits & 1);
+ point_swap_cond(&p1, &p1_, sw, ctx);
+
+ rsize = p1.z->nlimbs;
+ MPN_NORMALIZE(p1.z->d, rsize);
+ if (rsize == 0) {
+ mpi_set_ui(result->x, 1);
+ mpi_set_ui(result->z, 0);
+ } else {
+ z1 = mpi_new(0);
+ ec_invm(z1, p1.z, ctx);
+ ec_mulm(result->x, p1.x, z1, ctx);
+ mpi_set_ui(result->z, 1);
+ mpi_free(z1);
+ }
+
+ point_free(&p1);
+ point_free(&p2);
+ point_free(&p1_);
+ point_free(&p2_);
+ if (scalar_copied)
+ mpi_free(scalar);
+ return;
+ }
+
+ x1 = mpi_alloc_like(ctx->p);
+ y1 = mpi_alloc_like(ctx->p);
+ h = mpi_alloc_like(ctx->p);
+ k = mpi_copy(scalar);
+ yy = mpi_copy(point->y);
+
+ if (mpi_has_sign(k)) {
+ k->sign = 0;
+ ec_invm(yy, yy, ctx);
+ }
+
+ if (!mpi_cmp_ui(point->z, 1)) {
+ mpi_set(x1, point->x);
+ mpi_set(y1, yy);
+ } else {
+ MPI z2, z3;
+
+ z2 = mpi_alloc_like(ctx->p);
+ z3 = mpi_alloc_like(ctx->p);
+ ec_mulm(z2, point->z, point->z, ctx);
+ ec_mulm(z3, point->z, z2, ctx);
+ ec_invm(z2, z2, ctx);
+ ec_mulm(x1, point->x, z2, ctx);
+ ec_invm(z3, z3, ctx);
+ ec_mulm(y1, yy, z3, ctx);
+ mpi_free(z2);
+ mpi_free(z3);
+ }
+ z1 = mpi_copy(mpi_const(MPI_C_ONE));
+
+ mpi_mul(h, k, mpi_const(MPI_C_THREE)); /* h = 3k */
+ loops = mpi_get_nbits(h);
+ if (loops < 2) {
+ /* If SCALAR is zero, the above mpi_mul sets H to zero and thus
+ * LOOPs will be zero. To avoid an underflow of I in the main
+ * loop we set LOOP to 2 and the result to (0,0,0).
+ */
+ loops = 2;
+ mpi_clear(result->x);
+ mpi_clear(result->y);
+ mpi_clear(result->z);
+ } else {
+ mpi_set(result->x, point->x);
+ mpi_set(result->y, yy);
+ mpi_set(result->z, point->z);
+ }
+ mpi_free(yy); yy = NULL;
+
+ p1.x = x1; x1 = NULL;
+ p1.y = y1; y1 = NULL;
+ p1.z = z1; z1 = NULL;
+ point_init(&p2);
+ point_init(&p1inv);
+
+ /* Invert point: y = p - y mod p */
+ point_set(&p1inv, &p1);
+ ec_subm(p1inv.y, ctx->p, p1inv.y, ctx);
+
+ for (i = loops-2; i > 0; i--) {
+ mpi_ec_dup_point(result, result, ctx);
+ if (mpi_test_bit(h, i) == 1 && mpi_test_bit(k, i) == 0) {
+ point_set(&p2, result);
+ mpi_ec_add_points(result, &p2, &p1, ctx);
+ }
+ if (mpi_test_bit(h, i) == 0 && mpi_test_bit(k, i) == 1) {
+ point_set(&p2, result);
+ mpi_ec_add_points(result, &p2, &p1inv, ctx);
+ }
+ }
+
+ point_free(&p1);
+ point_free(&p2);
+ point_free(&p1inv);
+ mpi_free(h);
+ mpi_free(k);
+}
+EXPORT_SYMBOL_GPL(mpi_ec_mul_point);
+
+/* Return true if POINT is on the curve described by CTX. */
+int mpi_ec_curve_point(MPI_POINT point, struct mpi_ec_ctx *ctx)
+{
+ int res = 0;
+ MPI x, y, w;
+
+ x = mpi_new(0);
+ y = mpi_new(0);
+ w = mpi_new(0);
+
+ /* Check that the point is in range. This needs to be done here and
+ * not after conversion to affine coordinates.
+ */
+ if (mpi_cmpabs(point->x, ctx->p) >= 0)
+ goto leave;
+ if (mpi_cmpabs(point->y, ctx->p) >= 0)
+ goto leave;
+ if (mpi_cmpabs(point->z, ctx->p) >= 0)
+ goto leave;
+
+ switch (ctx->model) {
+ case MPI_EC_WEIERSTRASS:
+ {
+ MPI xxx;
+
+ if (mpi_ec_get_affine(x, y, point, ctx))
+ goto leave;
+
+ xxx = mpi_new(0);
+
+ /* y^2 == x^3 + a·x + b */
+ ec_pow2(y, y, ctx);
+
+ ec_pow3(xxx, x, ctx);
+ ec_mulm(w, ctx->a, x, ctx);
+ ec_addm(w, w, ctx->b, ctx);
+ ec_addm(w, w, xxx, ctx);
+
+ if (!mpi_cmp(y, w))
+ res = 1;
+
+ mpi_free(xxx);
+ }
+ break;
+
+ case MPI_EC_MONTGOMERY:
+ {
+#define xx y
+ /* With Montgomery curve, only X-coordinate is valid. */
+ if (mpi_ec_get_affine(x, NULL, point, ctx))
+ goto leave;
+
+ /* The equation is: b * y^2 == x^3 + a · x^2 + x */
+ /* We check if right hand is quadratic residue or not by
+ * Euler's criterion.
+ */
+ /* CTX->A has (a-2)/4 and CTX->B has b^-1 */
+ ec_mulm(w, ctx->a, mpi_const(MPI_C_FOUR), ctx);
+ ec_addm(w, w, mpi_const(MPI_C_TWO), ctx);
+ ec_mulm(w, w, x, ctx);
+ ec_pow2(xx, x, ctx);
+ ec_addm(w, w, xx, ctx);
+ ec_addm(w, w, mpi_const(MPI_C_ONE), ctx);
+ ec_mulm(w, w, x, ctx);
+ ec_mulm(w, w, ctx->b, ctx);
+#undef xx
+ /* Compute Euler's criterion: w^(p-1)/2 */
+#define p_minus1 y
+ ec_subm(p_minus1, ctx->p, mpi_const(MPI_C_ONE), ctx);
+ mpi_rshift(p_minus1, p_minus1, 1);
+ ec_powm(w, w, p_minus1, ctx);
+
+ res = !mpi_cmp_ui(w, 1);
+#undef p_minus1
+ }
+ break;
+
+ case MPI_EC_EDWARDS:
+ {
+ if (mpi_ec_get_affine(x, y, point, ctx))
+ goto leave;
+
+ mpi_resize(w, ctx->p->nlimbs);
+ w->nlimbs = ctx->p->nlimbs;
+
+ /* a · x^2 + y^2 - 1 - b · x^2 · y^2 == 0 */
+ ctx->pow2(x, x, ctx);
+ ctx->pow2(y, y, ctx);
+ if (ctx->dialect == ECC_DIALECT_ED25519)
+ ctx->subm(w, ctx->p, x, ctx);
+ else
+ ctx->mulm(w, ctx->a, x, ctx);
+ ctx->addm(w, w, y, ctx);
+ ctx->mulm(x, x, y, ctx);
+ ctx->mulm(x, x, ctx->b, ctx);
+ ctx->subm(w, w, x, ctx);
+ if (!mpi_cmp_ui(w, 1))
+ res = 1;
+ }
+ break;
+ }
+
+leave:
+ mpi_free(w);
+ mpi_free(x);
+ mpi_free(y);
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(mpi_ec_curve_point);
diff --git a/lib/mpi/mpi-add.c b/lib/mpi/mpi-add.c
new file mode 100644
index 0000000..2cdae54
--- /dev/null
+++ b/lib/mpi/mpi-add.c
@@ -0,0 +1,155 @@
+/* mpi-add.c - MPI functions
+ * Copyright (C) 1994, 1996, 1998, 2001, 2002,
+ * 2003 Free Software Foundation, Inc.
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ */
+
+#include "mpi-internal.h"
+
+/****************
+ * Add the unsigned integer V to the mpi-integer U and store the
+ * result in W. U and V may be the same.
+ */
+void mpi_add_ui(MPI w, MPI u, unsigned long v)
+{
+ mpi_ptr_t wp, up;
+ mpi_size_t usize, wsize;
+ int usign, wsign;
+
+ usize = u->nlimbs;
+ usign = u->sign;
+ wsign = 0;
+
+ /* If not space for W (and possible carry), increase space. */
+ wsize = usize + 1;
+ if (w->alloced < wsize)
+ mpi_resize(w, wsize);
+
+ /* These must be after realloc (U may be the same as W). */
+ up = u->d;
+ wp = w->d;
+
+ if (!usize) { /* simple */
+ wp[0] = v;
+ wsize = v ? 1:0;
+ } else if (!usign) { /* mpi is not negative */
+ mpi_limb_t cy;
+ cy = mpihelp_add_1(wp, up, usize, v);
+ wp[usize] = cy;
+ wsize = usize + cy;
+ } else {
+ /* The signs are different. Need exact comparison to determine
+ * which operand to subtract from which.
+ */
+ if (usize == 1 && up[0] < v) {
+ wp[0] = v - up[0];
+ wsize = 1;
+ } else {
+ mpihelp_sub_1(wp, up, usize, v);
+ /* Size can decrease with at most one limb. */
+ wsize = usize - (wp[usize-1] == 0);
+ wsign = 1;
+ }
+ }
+
+ w->nlimbs = wsize;
+ w->sign = wsign;
+}
+
+
+void mpi_add(MPI w, MPI u, MPI v)
+{
+ mpi_ptr_t wp, up, vp;
+ mpi_size_t usize, vsize, wsize;
+ int usign, vsign, wsign;
+
+ if (u->nlimbs < v->nlimbs) { /* Swap U and V. */
+ usize = v->nlimbs;
+ usign = v->sign;
+ vsize = u->nlimbs;
+ vsign = u->sign;
+ wsize = usize + 1;
+ RESIZE_IF_NEEDED(w, wsize);
+ /* These must be after realloc (u or v may be the same as w). */
+ up = v->d;
+ vp = u->d;
+ } else {
+ usize = u->nlimbs;
+ usign = u->sign;
+ vsize = v->nlimbs;
+ vsign = v->sign;
+ wsize = usize + 1;
+ RESIZE_IF_NEEDED(w, wsize);
+ /* These must be after realloc (u or v may be the same as w). */
+ up = u->d;
+ vp = v->d;
+ }
+ wp = w->d;
+ wsign = 0;
+
+ if (!vsize) { /* simple */
+ MPN_COPY(wp, up, usize);
+ wsize = usize;
+ wsign = usign;
+ } else if (usign != vsign) { /* different sign */
+ /* This test is right since USIZE >= VSIZE */
+ if (usize != vsize) {
+ mpihelp_sub(wp, up, usize, vp, vsize);
+ wsize = usize;
+ MPN_NORMALIZE(wp, wsize);
+ wsign = usign;
+ } else if (mpihelp_cmp(up, vp, usize) < 0) {
+ mpihelp_sub_n(wp, vp, up, usize);
+ wsize = usize;
+ MPN_NORMALIZE(wp, wsize);
+ if (!usign)
+ wsign = 1;
+ } else {
+ mpihelp_sub_n(wp, up, vp, usize);
+ wsize = usize;
+ MPN_NORMALIZE(wp, wsize);
+ if (usign)
+ wsign = 1;
+ }
+ } else { /* U and V have same sign. Add them. */
+ mpi_limb_t cy = mpihelp_add(wp, up, usize, vp, vsize);
+ wp[usize] = cy;
+ wsize = usize + cy;
+ if (usign)
+ wsign = 1;
+ }
+
+ w->nlimbs = wsize;
+ w->sign = wsign;
+}
+EXPORT_SYMBOL_GPL(mpi_add);
+
+void mpi_sub(MPI w, MPI u, MPI v)
+{
+ MPI vv = mpi_copy(v);
+ vv->sign = !vv->sign;
+ mpi_add(w, u, vv);
+ mpi_free(vv);
+}
+
+
+void mpi_addm(MPI w, MPI u, MPI v, MPI m)
+{
+ mpi_add(w, u, v);
+ mpi_mod(w, w, m);
+}
+EXPORT_SYMBOL_GPL(mpi_addm);
+
+void mpi_subm(MPI w, MPI u, MPI v, MPI m)
+{
+ mpi_sub(w, u, v);
+ mpi_mod(w, w, m);
+}
+EXPORT_SYMBOL_GPL(mpi_subm);
diff --git a/lib/mpi/mpi-bit.c b/lib/mpi/mpi-bit.c
index 503537e..142b680 100644
--- a/lib/mpi/mpi-bit.c
+++ b/lib/mpi/mpi-bit.c
@@ -1,4 +1,4 @@
-/* mpi-bit.c - MPI bit level fucntions
+/* mpi-bit.c - MPI bit level functions
* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
@@ -32,6 +32,7 @@
for (; a->nlimbs && !a->d[a->nlimbs - 1]; a->nlimbs--)
;
}
+EXPORT_SYMBOL_GPL(mpi_normalize);
/****************
* Return the number of bits in A.
@@ -54,3 +55,253 @@
return n;
}
EXPORT_SYMBOL_GPL(mpi_get_nbits);
+
+/****************
+ * Test whether bit N is set.
+ */
+int mpi_test_bit(MPI a, unsigned int n)
+{
+ unsigned int limbno, bitno;
+ mpi_limb_t limb;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return 0; /* too far left: this is a 0 */
+ limb = a->d[limbno];
+ return (limb & (A_LIMB_1 << bitno)) ? 1 : 0;
+}
+EXPORT_SYMBOL_GPL(mpi_test_bit);
+
+/****************
+ * Set bit N of A.
+ */
+void mpi_set_bit(MPI a, unsigned int n)
+{
+ unsigned int i, limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs) {
+ for (i = a->nlimbs; i < a->alloced; i++)
+ a->d[i] = 0;
+ mpi_resize(a, limbno+1);
+ a->nlimbs = limbno+1;
+ }
+ a->d[limbno] |= (A_LIMB_1<<bitno);
+}
+
+/****************
+ * Set bit N of A. and clear all bits above
+ */
+void mpi_set_highbit(MPI a, unsigned int n)
+{
+ unsigned int i, limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs) {
+ for (i = a->nlimbs; i < a->alloced; i++)
+ a->d[i] = 0;
+ mpi_resize(a, limbno+1);
+ a->nlimbs = limbno+1;
+ }
+ a->d[limbno] |= (A_LIMB_1<<bitno);
+ for (bitno++; bitno < BITS_PER_MPI_LIMB; bitno++)
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+ a->nlimbs = limbno+1;
+}
+EXPORT_SYMBOL_GPL(mpi_set_highbit);
+
+/****************
+ * clear bit N of A and all bits above
+ */
+void mpi_clear_highbit(MPI a, unsigned int n)
+{
+ unsigned int limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return; /* not allocated, therefore no need to clear bits :-) */
+
+ for ( ; bitno < BITS_PER_MPI_LIMB; bitno++)
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+ a->nlimbs = limbno+1;
+}
+
+/****************
+ * Clear bit N of A.
+ */
+void mpi_clear_bit(MPI a, unsigned int n)
+{
+ unsigned int limbno, bitno;
+
+ limbno = n / BITS_PER_MPI_LIMB;
+ bitno = n % BITS_PER_MPI_LIMB;
+
+ if (limbno >= a->nlimbs)
+ return; /* Don't need to clear this bit, it's far too left. */
+ a->d[limbno] &= ~(A_LIMB_1 << bitno);
+}
+EXPORT_SYMBOL_GPL(mpi_clear_bit);
+
+
+/****************
+ * Shift A by COUNT limbs to the right
+ * This is used only within the MPI library
+ */
+void mpi_rshift_limbs(MPI a, unsigned int count)
+{
+ mpi_ptr_t ap = a->d;
+ mpi_size_t n = a->nlimbs;
+ unsigned int i;
+
+ if (count >= n) {
+ a->nlimbs = 0;
+ return;
+ }
+
+ for (i = 0; i < n - count; i++)
+ ap[i] = ap[i+count];
+ ap[i] = 0;
+ a->nlimbs -= count;
+}
+
+/*
+ * Shift A by N bits to the right.
+ */
+void mpi_rshift(MPI x, MPI a, unsigned int n)
+{
+ mpi_size_t xsize;
+ unsigned int i;
+ unsigned int nlimbs = (n/BITS_PER_MPI_LIMB);
+ unsigned int nbits = (n%BITS_PER_MPI_LIMB);
+
+ if (x == a) {
+ /* In-place operation. */
+ if (nlimbs >= x->nlimbs) {
+ x->nlimbs = 0;
+ return;
+ }
+
+ if (nlimbs) {
+ for (i = 0; i < x->nlimbs - nlimbs; i++)
+ x->d[i] = x->d[i+nlimbs];
+ x->d[i] = 0;
+ x->nlimbs -= nlimbs;
+ }
+ if (x->nlimbs && nbits)
+ mpihelp_rshift(x->d, x->d, x->nlimbs, nbits);
+ } else if (nlimbs) {
+ /* Copy and shift by more or equal bits than in a limb. */
+ xsize = a->nlimbs;
+ x->sign = a->sign;
+ RESIZE_IF_NEEDED(x, xsize);
+ x->nlimbs = xsize;
+ for (i = 0; i < a->nlimbs; i++)
+ x->d[i] = a->d[i];
+ x->nlimbs = i;
+
+ if (nlimbs >= x->nlimbs) {
+ x->nlimbs = 0;
+ return;
+ }
+
+ if (nlimbs) {
+ for (i = 0; i < x->nlimbs - nlimbs; i++)
+ x->d[i] = x->d[i+nlimbs];
+ x->d[i] = 0;
+ x->nlimbs -= nlimbs;
+ }
+
+ if (x->nlimbs && nbits)
+ mpihelp_rshift(x->d, x->d, x->nlimbs, nbits);
+ } else {
+ /* Copy and shift by less than bits in a limb. */
+ xsize = a->nlimbs;
+ x->sign = a->sign;
+ RESIZE_IF_NEEDED(x, xsize);
+ x->nlimbs = xsize;
+
+ if (xsize) {
+ if (nbits)
+ mpihelp_rshift(x->d, a->d, x->nlimbs, nbits);
+ else {
+ /* The rshift helper function is not specified for
+ * NBITS==0, thus we do a plain copy here.
+ */
+ for (i = 0; i < x->nlimbs; i++)
+ x->d[i] = a->d[i];
+ }
+ }
+ }
+ MPN_NORMALIZE(x->d, x->nlimbs);
+}
+
+/****************
+ * Shift A by COUNT limbs to the left
+ * This is used only within the MPI library
+ */
+void mpi_lshift_limbs(MPI a, unsigned int count)
+{
+ mpi_ptr_t ap;
+ int n = a->nlimbs;
+ int i;
+
+ if (!count || !n)
+ return;
+
+ RESIZE_IF_NEEDED(a, n+count);
+
+ ap = a->d;
+ for (i = n-1; i >= 0; i--)
+ ap[i+count] = ap[i];
+ for (i = 0; i < count; i++)
+ ap[i] = 0;
+ a->nlimbs += count;
+}
+
+/*
+ * Shift A by N bits to the left.
+ */
+void mpi_lshift(MPI x, MPI a, unsigned int n)
+{
+ unsigned int nlimbs = (n/BITS_PER_MPI_LIMB);
+ unsigned int nbits = (n%BITS_PER_MPI_LIMB);
+
+ if (x == a && !n)
+ return; /* In-place shift with an amount of zero. */
+
+ if (x != a) {
+ /* Copy A to X. */
+ unsigned int alimbs = a->nlimbs;
+ int asign = a->sign;
+ mpi_ptr_t xp, ap;
+
+ RESIZE_IF_NEEDED(x, alimbs+nlimbs+1);
+ xp = x->d;
+ ap = a->d;
+ MPN_COPY(xp, ap, alimbs);
+ x->nlimbs = alimbs;
+ x->flags = a->flags;
+ x->sign = asign;
+ }
+
+ if (nlimbs && !nbits) {
+ /* Shift a full number of limbs. */
+ mpi_lshift_limbs(x, nlimbs);
+ } else if (n) {
+ /* We use a very dump approach: Shift left by the number of
+ * limbs plus one and than fix it up by an rshift.
+ */
+ mpi_lshift_limbs(x, nlimbs+1);
+ mpi_rshift(x, x, BITS_PER_MPI_LIMB - nbits);
+ }
+
+ MPN_NORMALIZE(x->d, x->nlimbs);
+}
diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c
index d25e9e9..c4cfa3f 100644
--- a/lib/mpi/mpi-cmp.c
+++ b/lib/mpi/mpi-cmp.c
@@ -41,28 +41,54 @@
}
EXPORT_SYMBOL_GPL(mpi_cmp_ui);
-int mpi_cmp(MPI u, MPI v)
+static int do_mpi_cmp(MPI u, MPI v, int absmode)
{
- mpi_size_t usize, vsize;
+ mpi_size_t usize;
+ mpi_size_t vsize;
+ int usign;
+ int vsign;
int cmp;
mpi_normalize(u);
mpi_normalize(v);
+
usize = u->nlimbs;
vsize = v->nlimbs;
- if (!u->sign && v->sign)
+ usign = absmode ? 0 : u->sign;
+ vsign = absmode ? 0 : v->sign;
+
+ /* Compare sign bits. */
+
+ if (!usign && vsign)
return 1;
- if (u->sign && !v->sign)
+ if (usign && !vsign)
return -1;
- if (usize != vsize && !u->sign && !v->sign)
+
+ /* U and V are either both positive or both negative. */
+
+ if (usize != vsize && !usign && !vsign)
return usize - vsize;
- if (usize != vsize && u->sign && v->sign)
- return vsize - usize;
+ if (usize != vsize && usign && vsign)
+ return vsize + usize;
if (!usize)
return 0;
cmp = mpihelp_cmp(u->d, v->d, usize);
- if (u->sign)
- return -cmp;
- return cmp;
+ if (!cmp)
+ return 0;
+ if ((cmp < 0?1:0) == (usign?1:0))
+ return 1;
+
+ return -1;
+}
+
+int mpi_cmp(MPI u, MPI v)
+{
+ return do_mpi_cmp(u, v, 0);
}
EXPORT_SYMBOL_GPL(mpi_cmp);
+
+int mpi_cmpabs(MPI u, MPI v)
+{
+ return do_mpi_cmp(u, v, 1);
+}
+EXPORT_SYMBOL_GPL(mpi_cmpabs);
diff --git a/lib/mpi/mpi-div.c b/lib/mpi/mpi-div.c
new file mode 100644
index 0000000..45beab8
--- /dev/null
+++ b/lib/mpi/mpi-div.c
@@ -0,0 +1,234 @@
+/* mpi-div.c - MPI functions
+ * Copyright (C) 1994, 1996, 1998, 2001, 2002,
+ * 2003 Free Software Foundation, Inc.
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ */
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den);
+void mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor);
+
+void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor)
+{
+ int divisor_sign = divisor->sign;
+ MPI temp_divisor = NULL;
+
+ /* We need the original value of the divisor after the remainder has been
+ * preliminary calculated. We have to copy it to temporary space if it's
+ * the same variable as REM.
+ */
+ if (rem == divisor) {
+ temp_divisor = mpi_copy(divisor);
+ divisor = temp_divisor;
+ }
+
+ mpi_tdiv_r(rem, dividend, divisor);
+
+ if (((divisor_sign?1:0) ^ (dividend->sign?1:0)) && rem->nlimbs)
+ mpi_add(rem, rem, divisor);
+
+ if (temp_divisor)
+ mpi_free(temp_divisor);
+}
+
+void mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor)
+{
+ MPI tmp = mpi_alloc(mpi_get_nlimbs(quot));
+ mpi_fdiv_qr(quot, tmp, dividend, divisor);
+ mpi_free(tmp);
+}
+
+void mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor)
+{
+ int divisor_sign = divisor->sign;
+ MPI temp_divisor = NULL;
+
+ if (quot == divisor || rem == divisor) {
+ temp_divisor = mpi_copy(divisor);
+ divisor = temp_divisor;
+ }
+
+ mpi_tdiv_qr(quot, rem, dividend, divisor);
+
+ if ((divisor_sign ^ dividend->sign) && rem->nlimbs) {
+ mpi_sub_ui(quot, quot, 1);
+ mpi_add(rem, rem, divisor);
+ }
+
+ if (temp_divisor)
+ mpi_free(temp_divisor);
+}
+
+/* If den == quot, den needs temporary storage.
+ * If den == rem, den needs temporary storage.
+ * If num == quot, num needs temporary storage.
+ * If den has temporary storage, it can be normalized while being copied,
+ * i.e no extra storage should be allocated.
+ */
+
+void mpi_tdiv_r(MPI rem, MPI num, MPI den)
+{
+ mpi_tdiv_qr(NULL, rem, num, den);
+}
+
+void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
+{
+ mpi_ptr_t np, dp;
+ mpi_ptr_t qp, rp;
+ mpi_size_t nsize = num->nlimbs;
+ mpi_size_t dsize = den->nlimbs;
+ mpi_size_t qsize, rsize;
+ mpi_size_t sign_remainder = num->sign;
+ mpi_size_t sign_quotient = num->sign ^ den->sign;
+ unsigned int normalization_steps;
+ mpi_limb_t q_limb;
+ mpi_ptr_t marker[5];
+ int markidx = 0;
+
+ /* Ensure space is enough for quotient and remainder.
+ * We need space for an extra limb in the remainder, because it's
+ * up-shifted (normalized) below.
+ */
+ rsize = nsize + 1;
+ mpi_resize(rem, rsize);
+
+ qsize = rsize - dsize; /* qsize cannot be bigger than this. */
+ if (qsize <= 0) {
+ if (num != rem) {
+ rem->nlimbs = num->nlimbs;
+ rem->sign = num->sign;
+ MPN_COPY(rem->d, num->d, nsize);
+ }
+ if (quot) {
+ /* This needs to follow the assignment to rem, in case the
+ * numerator and quotient are the same.
+ */
+ quot->nlimbs = 0;
+ quot->sign = 0;
+ }
+ return;
+ }
+
+ if (quot)
+ mpi_resize(quot, qsize);
+
+ /* Read pointers here, when reallocation is finished. */
+ np = num->d;
+ dp = den->d;
+ rp = rem->d;
+
+ /* Optimize division by a single-limb divisor. */
+ if (dsize == 1) {
+ mpi_limb_t rlimb;
+ if (quot) {
+ qp = quot->d;
+ rlimb = mpihelp_divmod_1(qp, np, nsize, dp[0]);
+ qsize -= qp[qsize - 1] == 0;
+ quot->nlimbs = qsize;
+ quot->sign = sign_quotient;
+ } else
+ rlimb = mpihelp_mod_1(np, nsize, dp[0]);
+ rp[0] = rlimb;
+ rsize = rlimb != 0?1:0;
+ rem->nlimbs = rsize;
+ rem->sign = sign_remainder;
+ return;
+ }
+
+
+ if (quot) {
+ qp = quot->d;
+ /* Make sure QP and NP point to different objects. Otherwise the
+ * numerator would be gradually overwritten by the quotient limbs.
+ */
+ if (qp == np) { /* Copy NP object to temporary space. */
+ np = marker[markidx++] = mpi_alloc_limb_space(nsize);
+ MPN_COPY(np, qp, nsize);
+ }
+ } else /* Put quotient at top of remainder. */
+ qp = rp + dsize;
+
+ normalization_steps = count_leading_zeros(dp[dsize - 1]);
+
+ /* Normalize the denominator, i.e. make its most significant bit set by
+ * shifting it NORMALIZATION_STEPS bits to the left. Also shift the
+ * numerator the same number of steps (to keep the quotient the same!).
+ */
+ if (normalization_steps) {
+ mpi_ptr_t tp;
+ mpi_limb_t nlimb;
+
+ /* Shift up the denominator setting the most significant bit of
+ * the most significant word. Use temporary storage not to clobber
+ * the original contents of the denominator.
+ */
+ tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
+ mpihelp_lshift(tp, dp, dsize, normalization_steps);
+ dp = tp;
+
+ /* Shift up the numerator, possibly introducing a new most
+ * significant word. Move the shifted numerator in the remainder
+ * meanwhile.
+ */
+ nlimb = mpihelp_lshift(rp, np, nsize, normalization_steps);
+ if (nlimb) {
+ rp[nsize] = nlimb;
+ rsize = nsize + 1;
+ } else
+ rsize = nsize;
+ } else {
+ /* The denominator is already normalized, as required. Copy it to
+ * temporary space if it overlaps with the quotient or remainder.
+ */
+ if (dp == rp || (quot && (dp == qp))) {
+ mpi_ptr_t tp;
+
+ tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
+ MPN_COPY(tp, dp, dsize);
+ dp = tp;
+ }
+
+ /* Move the numerator to the remainder. */
+ if (rp != np)
+ MPN_COPY(rp, np, nsize);
+
+ rsize = nsize;
+ }
+
+ q_limb = mpihelp_divrem(qp, 0, rp, rsize, dp, dsize);
+
+ if (quot) {
+ qsize = rsize - dsize;
+ if (q_limb) {
+ qp[qsize] = q_limb;
+ qsize += 1;
+ }
+
+ quot->nlimbs = qsize;
+ quot->sign = sign_quotient;
+ }
+
+ rsize = dsize;
+ MPN_NORMALIZE(rp, rsize);
+
+ if (normalization_steps && rsize) {
+ mpihelp_rshift(rp, rp, rsize, normalization_steps);
+ rsize -= rp[rsize - 1] == 0?1:0;
+ }
+
+ rem->nlimbs = rsize;
+ rem->sign = sign_remainder;
+ while (markidx) {
+ markidx--;
+ mpi_free_limb_space(marker[markidx]);
+ }
+}
diff --git a/lib/mpi/mpi-internal.h b/lib/mpi/mpi-internal.h
index 91df5f0..5540021 100644
--- a/lib/mpi/mpi-internal.h
+++ b/lib/mpi/mpi-internal.h
@@ -52,6 +52,12 @@
typedef mpi_limb_t *mpi_ptr_t; /* pointer to a limb */
typedef int mpi_size_t; /* (must be a signed type) */
+#define RESIZE_IF_NEEDED(a, b) \
+ do { \
+ if ((a)->alloced < (b)) \
+ mpi_resize((a), (b)); \
+ } while (0)
+
/* Copy N limbs from S to D. */
#define MPN_COPY(d, s, n) \
do { \
@@ -60,6 +66,14 @@
(d)[_i] = (s)[_i]; \
} while (0)
+#define MPN_COPY_INCR(d, s, n) \
+ do { \
+ mpi_size_t _i; \
+ for (_i = 0; _i < (n); _i++) \
+ (d)[_i] = (s)[_i]; \
+ } while (0)
+
+
#define MPN_COPY_DECR(d, s, n) \
do { \
mpi_size_t _i; \
@@ -92,6 +106,38 @@
mul_n(prodp, up, vp, size, tspace); \
} while (0);
+/* Divide the two-limb number in (NH,,NL) by D, with DI being the largest
+ * limb not larger than (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB).
+ * If this would yield overflow, DI should be the largest possible number
+ * (i.e., only ones). For correct operation, the most significant bit of D
+ * has to be set. Put the quotient in Q and the remainder in R.
+ */
+#define UDIV_QRNND_PREINV(q, r, nh, nl, d, di) \
+ do { \
+ mpi_limb_t _ql __maybe_unused; \
+ mpi_limb_t _q, _r; \
+ mpi_limb_t _xh, _xl; \
+ umul_ppmm(_q, _ql, (nh), (di)); \
+ _q += (nh); /* DI is 2**BITS_PER_MPI_LIMB too small */ \
+ umul_ppmm(_xh, _xl, _q, (d)); \
+ sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl); \
+ if (_xh) { \
+ sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
+ _q++; \
+ if (_xh) { \
+ sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
+ _q++; \
+ } \
+ } \
+ if (_r >= (d)) { \
+ _r -= (d); \
+ _q++; \
+ } \
+ (r) = _r; \
+ (q) = _q; \
+ } while (0)
+
+
/*-- mpiutil.c --*/
mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
void mpi_free_limb_space(mpi_ptr_t a);
@@ -135,6 +181,8 @@
void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
mpi_ptr_t tspace);
+void mpihelp_mul_n(mpi_ptr_t prodp,
+ mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size);
int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
mpi_ptr_t up, mpi_size_t usize,
@@ -146,9 +194,14 @@
mpi_size_t s1_size, mpi_limb_t s2_limb);
/*-- mpih-div.c --*/
+mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
+ mpi_limb_t divisor_limb);
mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs,
mpi_ptr_t np, mpi_size_t nsize,
mpi_ptr_t dp, mpi_size_t dsize);
+mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr,
+ mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
+ mpi_limb_t divisor_limb);
/*-- generic_mpih-[lr]shift.c --*/
mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
diff --git a/lib/mpi/mpi-inv.c b/lib/mpi/mpi-inv.c
new file mode 100644
index 0000000..61e37d1
--- /dev/null
+++ b/lib/mpi/mpi-inv.c
@@ -0,0 +1,143 @@
+/* mpi-inv.c - MPI functions
+ * Copyright (C) 1998, 2001, 2002, 2003 Free Software Foundation, Inc.
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgcrypt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "mpi-internal.h"
+
+/****************
+ * Calculate the multiplicative inverse X of A mod N
+ * That is: Find the solution x for
+ * 1 = (a*x) mod n
+ */
+int mpi_invm(MPI x, MPI a, MPI n)
+{
+ /* Extended Euclid's algorithm (See TAOCP Vol II, 4.5.2, Alg X)
+ * modified according to Michael Penk's solution for Exercise 35
+ * with further enhancement
+ */
+ MPI u, v, u1, u2 = NULL, u3, v1, v2 = NULL, v3, t1, t2 = NULL, t3;
+ unsigned int k;
+ int sign;
+ int odd;
+
+ if (!mpi_cmp_ui(a, 0))
+ return 0; /* Inverse does not exists. */
+ if (!mpi_cmp_ui(n, 1))
+ return 0; /* Inverse does not exists. */
+
+ u = mpi_copy(a);
+ v = mpi_copy(n);
+
+ for (k = 0; !mpi_test_bit(u, 0) && !mpi_test_bit(v, 0); k++) {
+ mpi_rshift(u, u, 1);
+ mpi_rshift(v, v, 1);
+ }
+ odd = mpi_test_bit(v, 0);
+
+ u1 = mpi_alloc_set_ui(1);
+ if (!odd)
+ u2 = mpi_alloc_set_ui(0);
+ u3 = mpi_copy(u);
+ v1 = mpi_copy(v);
+ if (!odd) {
+ v2 = mpi_alloc(mpi_get_nlimbs(u));
+ mpi_sub(v2, u1, u); /* U is used as const 1 */
+ }
+ v3 = mpi_copy(v);
+ if (mpi_test_bit(u, 0)) { /* u is odd */
+ t1 = mpi_alloc_set_ui(0);
+ if (!odd) {
+ t2 = mpi_alloc_set_ui(1);
+ t2->sign = 1;
+ }
+ t3 = mpi_copy(v);
+ t3->sign = !t3->sign;
+ goto Y4;
+ } else {
+ t1 = mpi_alloc_set_ui(1);
+ if (!odd)
+ t2 = mpi_alloc_set_ui(0);
+ t3 = mpi_copy(u);
+ }
+
+ do {
+ do {
+ if (!odd) {
+ if (mpi_test_bit(t1, 0) || mpi_test_bit(t2, 0)) {
+ /* one is odd */
+ mpi_add(t1, t1, v);
+ mpi_sub(t2, t2, u);
+ }
+ mpi_rshift(t1, t1, 1);
+ mpi_rshift(t2, t2, 1);
+ mpi_rshift(t3, t3, 1);
+ } else {
+ if (mpi_test_bit(t1, 0))
+ mpi_add(t1, t1, v);
+ mpi_rshift(t1, t1, 1);
+ mpi_rshift(t3, t3, 1);
+ }
+Y4:
+ ;
+ } while (!mpi_test_bit(t3, 0)); /* while t3 is even */
+
+ if (!t3->sign) {
+ mpi_set(u1, t1);
+ if (!odd)
+ mpi_set(u2, t2);
+ mpi_set(u3, t3);
+ } else {
+ mpi_sub(v1, v, t1);
+ sign = u->sign; u->sign = !u->sign;
+ if (!odd)
+ mpi_sub(v2, u, t2);
+ u->sign = sign;
+ sign = t3->sign; t3->sign = !t3->sign;
+ mpi_set(v3, t3);
+ t3->sign = sign;
+ }
+ mpi_sub(t1, u1, v1);
+ if (!odd)
+ mpi_sub(t2, u2, v2);
+ mpi_sub(t3, u3, v3);
+ if (t1->sign) {
+ mpi_add(t1, t1, v);
+ if (!odd)
+ mpi_sub(t2, t2, u);
+ }
+ } while (mpi_cmp_ui(t3, 0)); /* while t3 != 0 */
+ /* mpi_lshift( u3, k ); */
+ mpi_set(x, u1);
+
+ mpi_free(u1);
+ mpi_free(v1);
+ mpi_free(t1);
+ if (!odd) {
+ mpi_free(u2);
+ mpi_free(v2);
+ mpi_free(t2);
+ }
+ mpi_free(u3);
+ mpi_free(v3);
+ mpi_free(t3);
+
+ mpi_free(u);
+ mpi_free(v);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(mpi_invm);
diff --git a/lib/mpi/mpi-mod.c b/lib/mpi/mpi-mod.c
new file mode 100644
index 0000000..54fcc01
--- /dev/null
+++ b/lib/mpi/mpi-mod.c
@@ -0,0 +1,157 @@
+/* mpi-mod.c - Modular reduction
+ * Copyright (C) 1998, 1999, 2001, 2002, 2003,
+ * 2007 Free Software Foundation, Inc.
+ *
+ * This file is part of Libgcrypt.
+ */
+
+
+#include "mpi-internal.h"
+#include "longlong.h"
+
+/* Context used with Barrett reduction. */
+struct barrett_ctx_s {
+ MPI m; /* The modulus - may not be modified. */
+ int m_copied; /* If true, M needs to be released. */
+ int k;
+ MPI y;
+ MPI r1; /* Helper MPI. */
+ MPI r2; /* Helper MPI. */
+ MPI r3; /* Helper MPI allocated on demand. */
+};
+
+
+
+void mpi_mod(MPI rem, MPI dividend, MPI divisor)
+{
+ mpi_fdiv_r(rem, dividend, divisor);
+}
+
+/* This function returns a new context for Barrett based operations on
+ * the modulus M. This context needs to be released using
+ * _gcry_mpi_barrett_free. If COPY is true M will be transferred to
+ * the context and the user may change M. If COPY is false, M may not
+ * be changed until gcry_mpi_barrett_free has been called.
+ */
+mpi_barrett_t mpi_barrett_init(MPI m, int copy)
+{
+ mpi_barrett_t ctx;
+ MPI tmp;
+
+ mpi_normalize(m);
+ ctx = kcalloc(1, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return NULL;
+
+ if (copy) {
+ ctx->m = mpi_copy(m);
+ ctx->m_copied = 1;
+ } else
+ ctx->m = m;
+
+ ctx->k = mpi_get_nlimbs(m);
+ tmp = mpi_alloc(ctx->k + 1);
+
+ /* Barrett precalculation: y = floor(b^(2k) / m). */
+ mpi_set_ui(tmp, 1);
+ mpi_lshift_limbs(tmp, 2 * ctx->k);
+ mpi_fdiv_q(tmp, tmp, m);
+
+ ctx->y = tmp;
+ ctx->r1 = mpi_alloc(2 * ctx->k + 1);
+ ctx->r2 = mpi_alloc(2 * ctx->k + 1);
+
+ return ctx;
+}
+
+void mpi_barrett_free(mpi_barrett_t ctx)
+{
+ if (ctx) {
+ mpi_free(ctx->y);
+ mpi_free(ctx->r1);
+ mpi_free(ctx->r2);
+ if (ctx->r3)
+ mpi_free(ctx->r3);
+ if (ctx->m_copied)
+ mpi_free(ctx->m);
+ kfree(ctx);
+ }
+}
+
+
+/* R = X mod M
+ *
+ * Using Barrett reduction. Before using this function
+ * _gcry_mpi_barrett_init must have been called to do the
+ * precalculations. CTX is the context created by this precalculation
+ * and also conveys M. If the Barret reduction could no be done a
+ * straightforward reduction method is used.
+ *
+ * We assume that these conditions are met:
+ * Input: x =(x_2k-1 ...x_0)_b
+ * m =(m_k-1 ....m_0)_b with m_k-1 != 0
+ * Output: r = x mod m
+ */
+void mpi_mod_barrett(MPI r, MPI x, mpi_barrett_t ctx)
+{
+ MPI m = ctx->m;
+ int k = ctx->k;
+ MPI y = ctx->y;
+ MPI r1 = ctx->r1;
+ MPI r2 = ctx->r2;
+ int sign;
+
+ mpi_normalize(x);
+ if (mpi_get_nlimbs(x) > 2*k) {
+ mpi_mod(r, x, m);
+ return;
+ }
+
+ sign = x->sign;
+ x->sign = 0;
+
+ /* 1. q1 = floor( x / b^k-1)
+ * q2 = q1 * y
+ * q3 = floor( q2 / b^k+1 )
+ * Actually, we don't need qx, we can work direct on r2
+ */
+ mpi_set(r2, x);
+ mpi_rshift_limbs(r2, k-1);
+ mpi_mul(r2, r2, y);
+ mpi_rshift_limbs(r2, k+1);
+
+ /* 2. r1 = x mod b^k+1
+ * r2 = q3 * m mod b^k+1
+ * r = r1 - r2
+ * 3. if r < 0 then r = r + b^k+1
+ */
+ mpi_set(r1, x);
+ if (r1->nlimbs > k+1) /* Quick modulo operation. */
+ r1->nlimbs = k+1;
+ mpi_mul(r2, r2, m);
+ if (r2->nlimbs > k+1) /* Quick modulo operation. */
+ r2->nlimbs = k+1;
+ mpi_sub(r, r1, r2);
+
+ if (mpi_has_sign(r)) {
+ if (!ctx->r3) {
+ ctx->r3 = mpi_alloc(k + 2);
+ mpi_set_ui(ctx->r3, 1);
+ mpi_lshift_limbs(ctx->r3, k + 1);
+ }
+ mpi_add(r, r, ctx->r3);
+ }
+
+ /* 4. while r >= m do r = r - m */
+ while (mpi_cmp(r, m) >= 0)
+ mpi_sub(r, r, m);
+
+ x->sign = sign;
+}
+
+
+void mpi_mul_barrett(MPI w, MPI u, MPI v, mpi_barrett_t ctx)
+{
+ mpi_mul(w, u, v);
+ mpi_mod_barrett(w, w, ctx);
+}
diff --git a/lib/mpi/mpi-mul.c b/lib/mpi/mpi-mul.c
new file mode 100644
index 0000000..8f5fa20
--- /dev/null
+++ b/lib/mpi/mpi-mul.c
@@ -0,0 +1,91 @@
+/* mpi-mul.c - MPI functions
+ * Copyright (C) 1994, 1996, 1998, 2001, 2002,
+ * 2003 Free Software Foundation, Inc.
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Note: This code is heavily based on the GNU MP Library.
+ * Actually it's the same code with only minor changes in the
+ * way the data is stored; this is to support the abstraction
+ * of an optional secure memory allocation which may be used
+ * to avoid revealing of sensitive data due to paging etc.
+ */
+
+#include "mpi-internal.h"
+
+void mpi_mul(MPI w, MPI u, MPI v)
+{
+ mpi_size_t usize, vsize, wsize;
+ mpi_ptr_t up, vp, wp;
+ mpi_limb_t cy;
+ int usign, vsign, sign_product;
+ int assign_wp = 0;
+ mpi_ptr_t tmp_limb = NULL;
+
+ if (u->nlimbs < v->nlimbs) {
+ /* Swap U and V. */
+ usize = v->nlimbs;
+ usign = v->sign;
+ up = v->d;
+ vsize = u->nlimbs;
+ vsign = u->sign;
+ vp = u->d;
+ } else {
+ usize = u->nlimbs;
+ usign = u->sign;
+ up = u->d;
+ vsize = v->nlimbs;
+ vsign = v->sign;
+ vp = v->d;
+ }
+ sign_product = usign ^ vsign;
+ wp = w->d;
+
+ /* Ensure W has space enough to store the result. */
+ wsize = usize + vsize;
+ if (w->alloced < wsize) {
+ if (wp == up || wp == vp) {
+ wp = mpi_alloc_limb_space(wsize);
+ assign_wp = 1;
+ } else {
+ mpi_resize(w, wsize);
+ wp = w->d;
+ }
+ } else { /* Make U and V not overlap with W. */
+ if (wp == up) {
+ /* W and U are identical. Allocate temporary space for U. */
+ up = tmp_limb = mpi_alloc_limb_space(usize);
+ /* Is V identical too? Keep it identical with U. */
+ if (wp == vp)
+ vp = up;
+ /* Copy to the temporary space. */
+ MPN_COPY(up, wp, usize);
+ } else if (wp == vp) {
+ /* W and V are identical. Allocate temporary space for V. */
+ vp = tmp_limb = mpi_alloc_limb_space(vsize);
+ /* Copy to the temporary space. */
+ MPN_COPY(vp, wp, vsize);
+ }
+ }
+
+ if (!vsize)
+ wsize = 0;
+ else {
+ mpihelp_mul(wp, up, usize, vp, vsize, &cy);
+ wsize -= cy ? 0:1;
+ }
+
+ if (assign_wp)
+ mpi_assign_limb_space(w, wp, wsize);
+ w->nlimbs = wsize;
+ w->sign = sign_product;
+ if (tmp_limb)
+ mpi_free_limb_space(tmp_limb);
+}
+
+void mpi_mulm(MPI w, MPI u, MPI v, MPI m)
+{
+ mpi_mul(w, u, v);
+ mpi_tdiv_r(w, w, m);
+}
+EXPORT_SYMBOL_GPL(mpi_mulm);
diff --git a/lib/mpi/mpi-sub-ui.c b/lib/mpi/mpi-sub-ui.c
new file mode 100644
index 0000000..b41b082
--- /dev/null
+++ b/lib/mpi/mpi-sub-ui.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* mpi-sub-ui.c - Subtract an unsigned integer from an MPI.
+ *
+ * Copyright 1991, 1993, 1994, 1996, 1999-2002, 2004, 2012, 2013, 2015
+ * Free Software Foundation, Inc.
+ *
+ * This file was based on the GNU MP Library source file:
+ * https://gmplib.org/repo/gmp-6.2/file/510b83519d1c/mpz/aors_ui.h
+ *
+ * The GNU MP Library is free software; you can redistribute it and/or modify
+ * it under the terms of either:
+ *
+ * * the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * or
+ *
+ * * the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any
+ * later version.
+ *
+ * or both in parallel, as here.
+ *
+ * The GNU MP Library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received copies of the GNU General Public License and the
+ * GNU Lesser General Public License along with the GNU MP Library. If not,
+ * see https://www.gnu.org/licenses/.
+ */
+
+#include "mpi-internal.h"
+
+int mpi_sub_ui(MPI w, MPI u, unsigned long vval)
+{
+ if (u->nlimbs == 0) {
+ if (mpi_resize(w, 1) < 0)
+ return -ENOMEM;
+ w->d[0] = vval;
+ w->nlimbs = (vval != 0);
+ w->sign = (vval != 0);
+ return 0;
+ }
+
+ /* If not space for W (and possible carry), increase space. */
+ if (mpi_resize(w, u->nlimbs + 1))
+ return -ENOMEM;
+
+ if (u->sign) {
+ mpi_limb_t cy;
+
+ cy = mpihelp_add_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval);
+ w->d[u->nlimbs] = cy;
+ w->nlimbs = u->nlimbs + cy;
+ w->sign = 1;
+ } else {
+ /* The signs are different. Need exact comparison to determine
+ * which operand to subtract from which.
+ */
+ if (u->nlimbs == 1 && u->d[0] < vval) {
+ w->d[0] = vval - u->d[0];
+ w->nlimbs = 1;
+ w->sign = 1;
+ } else {
+ mpihelp_sub_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval);
+ /* Size can decrease with at most one limb. */
+ w->nlimbs = (u->nlimbs - (w->d[u->nlimbs - 1] == 0));
+ w->sign = 0;
+ }
+ }
+
+ mpi_normalize(w);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mpi_sub_ui);
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index eead4b3..7ea225b 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -25,6 +25,7 @@
#include <linux/string.h>
#include "mpi-internal.h"
+#define MAX_EXTERN_SCAN_BYTES (16*1024*1024)
#define MAX_EXTERN_MPI_BITS 16384
/**
@@ -109,6 +110,112 @@
}
EXPORT_SYMBOL_GPL(mpi_read_from_buffer);
+/****************
+ * Fill the mpi VAL from the hex string in STR.
+ */
+int mpi_fromstr(MPI val, const char *str)
+{
+ int sign = 0;
+ int prepend_zero = 0;
+ int i, j, c, c1, c2;
+ unsigned int nbits, nbytes, nlimbs;
+ mpi_limb_t a;
+
+ if (*str == '-') {
+ sign = 1;
+ str++;
+ }
+
+ /* Skip optional hex prefix. */
+ if (*str == '0' && str[1] == 'x')
+ str += 2;
+
+ nbits = strlen(str);
+ if (nbits > MAX_EXTERN_SCAN_BYTES) {
+ mpi_clear(val);
+ return -EINVAL;
+ }
+ nbits *= 4;
+ if ((nbits % 8))
+ prepend_zero = 1;
+
+ nbytes = (nbits+7) / 8;
+ nlimbs = (nbytes+BYTES_PER_MPI_LIMB-1) / BYTES_PER_MPI_LIMB;
+
+ if (val->alloced < nlimbs)
+ mpi_resize(val, nlimbs);
+
+ i = BYTES_PER_MPI_LIMB - (nbytes % BYTES_PER_MPI_LIMB);
+ i %= BYTES_PER_MPI_LIMB;
+ j = val->nlimbs = nlimbs;
+ val->sign = sign;
+ for (; j > 0; j--) {
+ a = 0;
+ for (; i < BYTES_PER_MPI_LIMB; i++) {
+ if (prepend_zero) {
+ c1 = '0';
+ prepend_zero = 0;
+ } else
+ c1 = *str++;
+
+ if (!c1) {
+ mpi_clear(val);
+ return -EINVAL;
+ }
+ c2 = *str++;
+ if (!c2) {
+ mpi_clear(val);
+ return -EINVAL;
+ }
+ if (c1 >= '0' && c1 <= '9')
+ c = c1 - '0';
+ else if (c1 >= 'a' && c1 <= 'f')
+ c = c1 - 'a' + 10;
+ else if (c1 >= 'A' && c1 <= 'F')
+ c = c1 - 'A' + 10;
+ else {
+ mpi_clear(val);
+ return -EINVAL;
+ }
+ c <<= 4;
+ if (c2 >= '0' && c2 <= '9')
+ c |= c2 - '0';
+ else if (c2 >= 'a' && c2 <= 'f')
+ c |= c2 - 'a' + 10;
+ else if (c2 >= 'A' && c2 <= 'F')
+ c |= c2 - 'A' + 10;
+ else {
+ mpi_clear(val);
+ return -EINVAL;
+ }
+ a <<= 8;
+ a |= c;
+ }
+ i = 0;
+ val->d[j-1] = a;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mpi_fromstr);
+
+MPI mpi_scanval(const char *string)
+{
+ MPI a;
+
+ a = mpi_alloc(0);
+ if (!a)
+ return NULL;
+
+ if (mpi_fromstr(a, string)) {
+ mpi_free(a);
+ return NULL;
+ }
+ mpi_normalize(a);
+ return a;
+}
+EXPORT_SYMBOL_GPL(mpi_scanval);
+
static int count_lzeros(MPI a)
{
mpi_limb_t alimb;
@@ -413,3 +520,232 @@
return val;
}
EXPORT_SYMBOL_GPL(mpi_read_raw_from_sgl);
+
+/* Perform a two's complement operation on buffer P of size N bytes. */
+static void twocompl(unsigned char *p, unsigned int n)
+{
+ int i;
+
+ for (i = n-1; i >= 0 && !p[i]; i--)
+ ;
+ if (i >= 0) {
+ if ((p[i] & 0x01))
+ p[i] = (((p[i] ^ 0xfe) | 0x01) & 0xff);
+ else if ((p[i] & 0x02))
+ p[i] = (((p[i] ^ 0xfc) | 0x02) & 0xfe);
+ else if ((p[i] & 0x04))
+ p[i] = (((p[i] ^ 0xf8) | 0x04) & 0xfc);
+ else if ((p[i] & 0x08))
+ p[i] = (((p[i] ^ 0xf0) | 0x08) & 0xf8);
+ else if ((p[i] & 0x10))
+ p[i] = (((p[i] ^ 0xe0) | 0x10) & 0xf0);
+ else if ((p[i] & 0x20))
+ p[i] = (((p[i] ^ 0xc0) | 0x20) & 0xe0);
+ else if ((p[i] & 0x40))
+ p[i] = (((p[i] ^ 0x80) | 0x40) & 0xc0);
+ else
+ p[i] = 0x80;
+
+ for (i--; i >= 0; i--)
+ p[i] ^= 0xff;
+ }
+}
+
+int mpi_print(enum gcry_mpi_format format, unsigned char *buffer,
+ size_t buflen, size_t *nwritten, MPI a)
+{
+ unsigned int nbits = mpi_get_nbits(a);
+ size_t len;
+ size_t dummy_nwritten;
+ int negative;
+
+ if (!nwritten)
+ nwritten = &dummy_nwritten;
+
+ /* Libgcrypt does no always care to set clear the sign if the value
+ * is 0. For printing this is a bit of a surprise, in particular
+ * because if some of the formats don't support negative numbers but
+ * should be able to print a zero. Thus we need this extra test
+ * for a negative number.
+ */
+ if (a->sign && mpi_cmp_ui(a, 0))
+ negative = 1;
+ else
+ negative = 0;
+
+ len = buflen;
+ *nwritten = 0;
+ if (format == GCRYMPI_FMT_STD) {
+ unsigned char *tmp;
+ int extra = 0;
+ unsigned int n;
+
+ tmp = mpi_get_buffer(a, &n, NULL);
+ if (!tmp)
+ return -EINVAL;
+
+ if (negative) {
+ twocompl(tmp, n);
+ if (!(*tmp & 0x80)) {
+ /* Need to extend the sign. */
+ n++;
+ extra = 2;
+ }
+ } else if (n && (*tmp & 0x80)) {
+ /* Positive but the high bit of the returned buffer is set.
+ * Thus we need to print an extra leading 0x00 so that the
+ * output is interpreted as a positive number.
+ */
+ n++;
+ extra = 1;
+ }
+
+ if (buffer && n > len) {
+ /* The provided buffer is too short. */
+ kfree(tmp);
+ return -E2BIG;
+ }
+ if (buffer) {
+ unsigned char *s = buffer;
+
+ if (extra == 1)
+ *s++ = 0;
+ else if (extra)
+ *s++ = 0xff;
+ memcpy(s, tmp, n-!!extra);
+ }
+ kfree(tmp);
+ *nwritten = n;
+ return 0;
+ } else if (format == GCRYMPI_FMT_USG) {
+ unsigned int n = (nbits + 7)/8;
+
+ /* Note: We ignore the sign for this format. */
+ /* FIXME: for performance reasons we should put this into
+ * mpi_aprint because we can then use the buffer directly.
+ */
+
+ if (buffer && n > len)
+ return -E2BIG;
+ if (buffer) {
+ unsigned char *tmp;
+
+ tmp = mpi_get_buffer(a, &n, NULL);
+ if (!tmp)
+ return -EINVAL;
+ memcpy(buffer, tmp, n);
+ kfree(tmp);
+ }
+ *nwritten = n;
+ return 0;
+ } else if (format == GCRYMPI_FMT_PGP) {
+ unsigned int n = (nbits + 7)/8;
+
+ /* The PGP format can only handle unsigned integers. */
+ if (negative)
+ return -EINVAL;
+
+ if (buffer && n+2 > len)
+ return -E2BIG;
+
+ if (buffer) {
+ unsigned char *tmp;
+ unsigned char *s = buffer;
+
+ s[0] = nbits >> 8;
+ s[1] = nbits;
+
+ tmp = mpi_get_buffer(a, &n, NULL);
+ if (!tmp)
+ return -EINVAL;
+ memcpy(s+2, tmp, n);
+ kfree(tmp);
+ }
+ *nwritten = n+2;
+ return 0;
+ } else if (format == GCRYMPI_FMT_SSH) {
+ unsigned char *tmp;
+ int extra = 0;
+ unsigned int n;
+
+ tmp = mpi_get_buffer(a, &n, NULL);
+ if (!tmp)
+ return -EINVAL;
+
+ if (negative) {
+ twocompl(tmp, n);
+ if (!(*tmp & 0x80)) {
+ /* Need to extend the sign. */
+ n++;
+ extra = 2;
+ }
+ } else if (n && (*tmp & 0x80)) {
+ n++;
+ extra = 1;
+ }
+
+ if (buffer && n+4 > len) {
+ kfree(tmp);
+ return -E2BIG;
+ }
+
+ if (buffer) {
+ unsigned char *s = buffer;
+
+ *s++ = n >> 24;
+ *s++ = n >> 16;
+ *s++ = n >> 8;
+ *s++ = n;
+ if (extra == 1)
+ *s++ = 0;
+ else if (extra)
+ *s++ = 0xff;
+ memcpy(s, tmp, n-!!extra);
+ }
+ kfree(tmp);
+ *nwritten = 4+n;
+ return 0;
+ } else if (format == GCRYMPI_FMT_HEX) {
+ unsigned char *tmp;
+ int i;
+ int extra = 0;
+ unsigned int n = 0;
+
+ tmp = mpi_get_buffer(a, &n, NULL);
+ if (!tmp)
+ return -EINVAL;
+ if (!n || (*tmp & 0x80))
+ extra = 2;
+
+ if (buffer && 2*n + extra + negative + 1 > len) {
+ kfree(tmp);
+ return -E2BIG;
+ }
+ if (buffer) {
+ unsigned char *s = buffer;
+
+ if (negative)
+ *s++ = '-';
+ if (extra) {
+ *s++ = '0';
+ *s++ = '0';
+ }
+
+ for (i = 0; i < n; i++) {
+ unsigned int c = tmp[i];
+
+ *s++ = (c >> 4) < 10 ? '0'+(c>>4) : 'A'+(c>>4)-10;
+ c &= 15;
+ *s++ = c < 10 ? '0'+c : 'A'+c-10;
+ }
+ *s++ = 0;
+ *nwritten = s - buffer;
+ } else {
+ *nwritten = 2*n + extra + negative + 1;
+ }
+ kfree(tmp);
+ return 0;
+ } else
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(mpi_print);
diff --git a/lib/mpi/mpih-div.c b/lib/mpi/mpih-div.c
index 913a519..be70ee2 100644
--- a/lib/mpi/mpih-div.c
+++ b/lib/mpi/mpih-div.c
@@ -24,6 +24,150 @@
#define UDIV_TIME UMUL_TIME
#endif
+
+mpi_limb_t
+mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
+ mpi_limb_t divisor_limb)
+{
+ mpi_size_t i;
+ mpi_limb_t n1, n0, r;
+ mpi_limb_t dummy __maybe_unused;
+
+ /* Botch: Should this be handled at all? Rely on callers? */
+ if (!dividend_size)
+ return 0;
+
+ /* If multiplication is much faster than division, and the
+ * dividend is large, pre-invert the divisor, and use
+ * only multiplications in the inner loop.
+ *
+ * This test should be read:
+ * Does it ever help to use udiv_qrnnd_preinv?
+ * && Does what we save compensate for the inversion overhead?
+ */
+ if (UDIV_TIME > (2 * UMUL_TIME + 6)
+ && (UDIV_TIME - (2 * UMUL_TIME + 6)) * dividend_size > UDIV_TIME) {
+ int normalization_steps;
+
+ normalization_steps = count_leading_zeros(divisor_limb);
+ if (normalization_steps) {
+ mpi_limb_t divisor_limb_inverted;
+
+ divisor_limb <<= normalization_steps;
+
+ /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
+ * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
+ * most significant bit (with weight 2**N) implicit.
+ *
+ * Special case for DIVISOR_LIMB == 100...000.
+ */
+ if (!(divisor_limb << 1))
+ divisor_limb_inverted = ~(mpi_limb_t)0;
+ else
+ udiv_qrnnd(divisor_limb_inverted, dummy,
+ -divisor_limb, 0, divisor_limb);
+
+ n1 = dividend_ptr[dividend_size - 1];
+ r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
+
+ /* Possible optimization:
+ * if (r == 0
+ * && divisor_limb > ((n1 << normalization_steps)
+ * | (dividend_ptr[dividend_size - 2] >> ...)))
+ * ...one division less...
+ */
+ for (i = dividend_size - 2; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ UDIV_QRNND_PREINV(dummy, r, r,
+ ((n1 << normalization_steps)
+ | (n0 >> (BITS_PER_MPI_LIMB - normalization_steps))),
+ divisor_limb, divisor_limb_inverted);
+ n1 = n0;
+ }
+ UDIV_QRNND_PREINV(dummy, r, r,
+ n1 << normalization_steps,
+ divisor_limb, divisor_limb_inverted);
+ return r >> normalization_steps;
+ } else {
+ mpi_limb_t divisor_limb_inverted;
+
+ /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
+ * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
+ * most significant bit (with weight 2**N) implicit.
+ *
+ * Special case for DIVISOR_LIMB == 100...000.
+ */
+ if (!(divisor_limb << 1))
+ divisor_limb_inverted = ~(mpi_limb_t)0;
+ else
+ udiv_qrnnd(divisor_limb_inverted, dummy,
+ -divisor_limb, 0, divisor_limb);
+
+ i = dividend_size - 1;
+ r = dividend_ptr[i];
+
+ if (r >= divisor_limb)
+ r = 0;
+ else
+ i--;
+
+ for ( ; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ UDIV_QRNND_PREINV(dummy, r, r,
+ n0, divisor_limb, divisor_limb_inverted);
+ }
+ return r;
+ }
+ } else {
+ if (UDIV_NEEDS_NORMALIZATION) {
+ int normalization_steps;
+
+ normalization_steps = count_leading_zeros(divisor_limb);
+ if (normalization_steps) {
+ divisor_limb <<= normalization_steps;
+
+ n1 = dividend_ptr[dividend_size - 1];
+ r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
+
+ /* Possible optimization:
+ * if (r == 0
+ * && divisor_limb > ((n1 << normalization_steps)
+ * | (dividend_ptr[dividend_size - 2] >> ...)))
+ * ...one division less...
+ */
+ for (i = dividend_size - 2; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ udiv_qrnnd(dummy, r, r,
+ ((n1 << normalization_steps)
+ | (n0 >> (BITS_PER_MPI_LIMB - normalization_steps))),
+ divisor_limb);
+ n1 = n0;
+ }
+ udiv_qrnnd(dummy, r, r,
+ n1 << normalization_steps,
+ divisor_limb);
+ return r >> normalization_steps;
+ }
+ }
+ /* No normalization needed, either because udiv_qrnnd doesn't require
+ * it, or because DIVISOR_LIMB is already normalized.
+ */
+ i = dividend_size - 1;
+ r = dividend_ptr[i];
+
+ if (r >= divisor_limb)
+ r = 0;
+ else
+ i--;
+
+ for (; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ udiv_qrnnd(dummy, r, r, n0, divisor_limb);
+ }
+ return r;
+ }
+}
+
/* Divide num (NP/NSIZE) by den (DP/DSIZE) and write
* the NSIZE-DSIZE least significant quotient limbs at QP
* and the DSIZE long remainder at NP. If QEXTRA_LIMBS is
@@ -221,3 +365,153 @@
return most_significant_q_limb;
}
+
+/****************
+ * Divide (DIVIDEND_PTR,,DIVIDEND_SIZE) by DIVISOR_LIMB.
+ * Write DIVIDEND_SIZE limbs of quotient at QUOT_PTR.
+ * Return the single-limb remainder.
+ * There are no constraints on the value of the divisor.
+ *
+ * QUOT_PTR and DIVIDEND_PTR might point to the same limb.
+ */
+
+mpi_limb_t
+mpihelp_divmod_1(mpi_ptr_t quot_ptr,
+ mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
+ mpi_limb_t divisor_limb)
+{
+ mpi_size_t i;
+ mpi_limb_t n1, n0, r;
+ mpi_limb_t dummy __maybe_unused;
+
+ if (!dividend_size)
+ return 0;
+
+ /* If multiplication is much faster than division, and the
+ * dividend is large, pre-invert the divisor, and use
+ * only multiplications in the inner loop.
+ *
+ * This test should be read:
+ * Does it ever help to use udiv_qrnnd_preinv?
+ * && Does what we save compensate for the inversion overhead?
+ */
+ if (UDIV_TIME > (2 * UMUL_TIME + 6)
+ && (UDIV_TIME - (2 * UMUL_TIME + 6)) * dividend_size > UDIV_TIME) {
+ int normalization_steps;
+
+ normalization_steps = count_leading_zeros(divisor_limb);
+ if (normalization_steps) {
+ mpi_limb_t divisor_limb_inverted;
+
+ divisor_limb <<= normalization_steps;
+
+ /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
+ * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
+ * most significant bit (with weight 2**N) implicit.
+ */
+ /* Special case for DIVISOR_LIMB == 100...000. */
+ if (!(divisor_limb << 1))
+ divisor_limb_inverted = ~(mpi_limb_t)0;
+ else
+ udiv_qrnnd(divisor_limb_inverted, dummy,
+ -divisor_limb, 0, divisor_limb);
+
+ n1 = dividend_ptr[dividend_size - 1];
+ r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
+
+ /* Possible optimization:
+ * if (r == 0
+ * && divisor_limb > ((n1 << normalization_steps)
+ * | (dividend_ptr[dividend_size - 2] >> ...)))
+ * ...one division less...
+ */
+ for (i = dividend_size - 2; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ UDIV_QRNND_PREINV(quot_ptr[i + 1], r, r,
+ ((n1 << normalization_steps)
+ | (n0 >> (BITS_PER_MPI_LIMB - normalization_steps))),
+ divisor_limb, divisor_limb_inverted);
+ n1 = n0;
+ }
+ UDIV_QRNND_PREINV(quot_ptr[0], r, r,
+ n1 << normalization_steps,
+ divisor_limb, divisor_limb_inverted);
+ return r >> normalization_steps;
+ } else {
+ mpi_limb_t divisor_limb_inverted;
+
+ /* Compute (2**2N - 2**N * DIVISOR_LIMB) / DIVISOR_LIMB. The
+ * result is a (N+1)-bit approximation to 1/DIVISOR_LIMB, with the
+ * most significant bit (with weight 2**N) implicit.
+ */
+ /* Special case for DIVISOR_LIMB == 100...000. */
+ if (!(divisor_limb << 1))
+ divisor_limb_inverted = ~(mpi_limb_t) 0;
+ else
+ udiv_qrnnd(divisor_limb_inverted, dummy,
+ -divisor_limb, 0, divisor_limb);
+
+ i = dividend_size - 1;
+ r = dividend_ptr[i];
+
+ if (r >= divisor_limb)
+ r = 0;
+ else
+ quot_ptr[i--] = 0;
+
+ for ( ; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ UDIV_QRNND_PREINV(quot_ptr[i], r, r,
+ n0, divisor_limb, divisor_limb_inverted);
+ }
+ return r;
+ }
+ } else {
+ if (UDIV_NEEDS_NORMALIZATION) {
+ int normalization_steps;
+
+ normalization_steps = count_leading_zeros(divisor_limb);
+ if (normalization_steps) {
+ divisor_limb <<= normalization_steps;
+
+ n1 = dividend_ptr[dividend_size - 1];
+ r = n1 >> (BITS_PER_MPI_LIMB - normalization_steps);
+
+ /* Possible optimization:
+ * if (r == 0
+ * && divisor_limb > ((n1 << normalization_steps)
+ * | (dividend_ptr[dividend_size - 2] >> ...)))
+ * ...one division less...
+ */
+ for (i = dividend_size - 2; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ udiv_qrnnd(quot_ptr[i + 1], r, r,
+ ((n1 << normalization_steps)
+ | (n0 >> (BITS_PER_MPI_LIMB - normalization_steps))),
+ divisor_limb);
+ n1 = n0;
+ }
+ udiv_qrnnd(quot_ptr[0], r, r,
+ n1 << normalization_steps,
+ divisor_limb);
+ return r >> normalization_steps;
+ }
+ }
+ /* No normalization needed, either because udiv_qrnnd doesn't require
+ * it, or because DIVISOR_LIMB is already normalized.
+ */
+ i = dividend_size - 1;
+ r = dividend_ptr[i];
+
+ if (r >= divisor_limb)
+ r = 0;
+ else
+ quot_ptr[i--] = 0;
+
+ for (; i >= 0; i--) {
+ n0 = dividend_ptr[i];
+ udiv_qrnnd(quot_ptr[i], r, r, n0, divisor_limb);
+ }
+ return r;
+ }
+}
diff --git a/lib/mpi/mpih-mul.c b/lib/mpi/mpih-mul.c
index a936475..e5f1c84 100644
--- a/lib/mpi/mpih-mul.c
+++ b/lib/mpi/mpih-mul.c
@@ -317,6 +317,31 @@
}
}
+
+void mpihelp_mul_n(mpi_ptr_t prodp,
+ mpi_ptr_t up, mpi_ptr_t vp, mpi_size_t size)
+{
+ if (up == vp) {
+ if (size < KARATSUBA_THRESHOLD)
+ mpih_sqr_n_basecase(prodp, up, size);
+ else {
+ mpi_ptr_t tspace;
+ tspace = mpi_alloc_limb_space(2 * size);
+ mpih_sqr_n(prodp, up, size, tspace);
+ mpi_free_limb_space(tspace);
+ }
+ } else {
+ if (size < KARATSUBA_THRESHOLD)
+ mul_n_basecase(prodp, up, vp, size);
+ else {
+ mpi_ptr_t tspace;
+ tspace = mpi_alloc_limb_space(2 * size);
+ mul_n(prodp, up, vp, size, tspace);
+ mpi_free_limb_space(tspace);
+ }
+ }
+}
+
int
mpihelp_mul_karatsuba_case(mpi_ptr_t prodp,
mpi_ptr_t up, mpi_size_t usize,
diff --git a/lib/mpi/mpiutil.c b/lib/mpi/mpiutil.c
index 0082502..e6c4b31 100644
--- a/lib/mpi/mpiutil.c
+++ b/lib/mpi/mpiutil.c
@@ -20,6 +20,63 @@
#include "mpi-internal.h"
+/* Constants allocated right away at startup. */
+static MPI constants[MPI_NUMBER_OF_CONSTANTS];
+
+/* Initialize the MPI subsystem. This is called early and allows to
+ * do some initialization without taking care of threading issues.
+ */
+static int __init mpi_init(void)
+{
+ int idx;
+ unsigned long value;
+
+ for (idx = 0; idx < MPI_NUMBER_OF_CONSTANTS; idx++) {
+ switch (idx) {
+ case MPI_C_ZERO:
+ value = 0;
+ break;
+ case MPI_C_ONE:
+ value = 1;
+ break;
+ case MPI_C_TWO:
+ value = 2;
+ break;
+ case MPI_C_THREE:
+ value = 3;
+ break;
+ case MPI_C_FOUR:
+ value = 4;
+ break;
+ case MPI_C_EIGHT:
+ value = 8;
+ break;
+ default:
+ pr_err("MPI: invalid mpi_const selector %d\n", idx);
+ return -EFAULT;
+ }
+ constants[idx] = mpi_alloc_set_ui(value);
+ constants[idx]->flags = (16|32);
+ }
+
+ return 0;
+}
+postcore_initcall(mpi_init);
+
+/* Return a constant MPI descripbed by NO which is one of the
+ * MPI_C_xxx macros. There is no need to copy this returned value; it
+ * may be used directly.
+ */
+MPI mpi_const(enum gcry_mpi_constants no)
+{
+ if ((int)no < 0 || no > MPI_NUMBER_OF_CONSTANTS)
+ pr_err("MPI: invalid mpi_const selector %d\n", no);
+ if (!constants[no])
+ pr_err("MPI: MPI subsystem not initialized\n");
+ return constants[no];
+}
+EXPORT_SYMBOL_GPL(mpi_const);
+
/****************
* Note: It was a bad idea to use the number of limbs to allocate
* because on a alpha the limbs are large but we normally need
@@ -69,7 +126,7 @@
if (!a)
return;
- kzfree(a);
+ kfree_sensitive(a);
}
void mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs)
@@ -95,7 +152,7 @@
if (!p)
return -ENOMEM;
memcpy(p, a->d, a->alloced * sizeof(mpi_limb_t));
- kzfree(a->d);
+ kfree_sensitive(a->d);
a->d = p;
} else {
a->d = kcalloc(nlimbs, sizeof(mpi_limb_t), GFP_KERNEL);
@@ -106,13 +163,22 @@
return 0;
}
+void mpi_clear(MPI a)
+{
+ if (!a)
+ return;
+ a->nlimbs = 0;
+ a->flags = 0;
+}
+EXPORT_SYMBOL_GPL(mpi_clear);
+
void mpi_free(MPI a)
{
if (!a)
return;
if (a->flags & 4)
- kzfree(a->d);
+ kfree_sensitive(a->d);
else
mpi_free_limb_space(a->d);
@@ -122,5 +188,143 @@
}
EXPORT_SYMBOL_GPL(mpi_free);
+/****************
+ * Note: This copy function should not interpret the MPI
+ * but copy it transparently.
+ */
+MPI mpi_copy(MPI a)
+{
+ int i;
+ MPI b;
+
+ if (a) {
+ b = mpi_alloc(a->nlimbs);
+ b->nlimbs = a->nlimbs;
+ b->sign = a->sign;
+ b->flags = a->flags;
+ b->flags &= ~(16|32); /* Reset the immutable and constant flags. */
+ for (i = 0; i < b->nlimbs; i++)
+ b->d[i] = a->d[i];
+ } else
+ b = NULL;
+ return b;
+}
+
+/****************
+ * This function allocates an MPI which is optimized to hold
+ * a value as large as the one given in the argument and allocates it
+ * with the same flags as A.
+ */
+MPI mpi_alloc_like(MPI a)
+{
+ MPI b;
+
+ if (a) {
+ b = mpi_alloc(a->nlimbs);
+ b->nlimbs = 0;
+ b->sign = 0;
+ b->flags = a->flags;
+ } else
+ b = NULL;
+
+ return b;
+}
+
+
+/* Set U into W and release U. If W is NULL only U will be released. */
+void mpi_snatch(MPI w, MPI u)
+{
+ if (w) {
+ mpi_assign_limb_space(w, u->d, u->alloced);
+ w->nlimbs = u->nlimbs;
+ w->sign = u->sign;
+ w->flags = u->flags;
+ u->alloced = 0;
+ u->nlimbs = 0;
+ u->d = NULL;
+ }
+ mpi_free(u);
+}
+
+
+MPI mpi_set(MPI w, MPI u)
+{
+ mpi_ptr_t wp, up;
+ mpi_size_t usize = u->nlimbs;
+ int usign = u->sign;
+
+ if (!w)
+ w = mpi_alloc(mpi_get_nlimbs(u));
+ RESIZE_IF_NEEDED(w, usize);
+ wp = w->d;
+ up = u->d;
+ MPN_COPY(wp, up, usize);
+ w->nlimbs = usize;
+ w->flags = u->flags;
+ w->flags &= ~(16|32); /* Reset the immutable and constant flags. */
+ w->sign = usign;
+ return w;
+}
+EXPORT_SYMBOL_GPL(mpi_set);
+
+MPI mpi_set_ui(MPI w, unsigned long u)
+{
+ if (!w)
+ w = mpi_alloc(1);
+ /* FIXME: If U is 0 we have no need to resize and thus possible
+ * allocating the the limbs.
+ */
+ RESIZE_IF_NEEDED(w, 1);
+ w->d[0] = u;
+ w->nlimbs = u ? 1 : 0;
+ w->sign = 0;
+ w->flags = 0;
+ return w;
+}
+EXPORT_SYMBOL_GPL(mpi_set_ui);
+
+MPI mpi_alloc_set_ui(unsigned long u)
+{
+ MPI w = mpi_alloc(1);
+ w->d[0] = u;
+ w->nlimbs = u ? 1 : 0;
+ w->sign = 0;
+ return w;
+}
+
+/****************
+ * Swap the value of A and B, when SWAP is 1.
+ * Leave the value when SWAP is 0.
+ * This implementation should be constant-time regardless of SWAP.
+ */
+void mpi_swap_cond(MPI a, MPI b, unsigned long swap)
+{
+ mpi_size_t i;
+ mpi_size_t nlimbs;
+ mpi_limb_t mask = ((mpi_limb_t)0) - swap;
+ mpi_limb_t x;
+
+ if (a->alloced > b->alloced)
+ nlimbs = b->alloced;
+ else
+ nlimbs = a->alloced;
+ if (a->nlimbs > nlimbs || b->nlimbs > nlimbs)
+ return;
+
+ for (i = 0; i < nlimbs; i++) {
+ x = mask & (a->d[i] ^ b->d[i]);
+ a->d[i] = a->d[i] ^ x;
+ b->d[i] = b->d[i] ^ x;
+ }
+
+ x = mask & (a->nlimbs ^ b->nlimbs);
+ a->nlimbs = a->nlimbs ^ x;
+ b->nlimbs = b->nlimbs ^ x;
+
+ x = mask & (a->sign ^ b->sign);
+ a->sign = a->sign ^ x;
+ b->sign = b->sign ^ x;
+}
+
MODULE_DESCRIPTION("Multiprecision maths library");
MODULE_LICENSE("GPL");