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authorauth12 <[email protected]>2020-07-22 08:34:12 -0700
committerauth12 <[email protected]>2020-07-22 08:34:12 -0700
commit5015ddb9b1eee748efc24056e46f81888c975f7a (patch)
treea810f6ee90f8bfe0e934fdd9142198e6b3862957 /wolfcrypt/src/tfm.c
downloadwolfssl_windows-5015ddb9b1eee748efc24056e46f81888c975f7a.tar.xz
wolfssl_windows-5015ddb9b1eee748efc24056e46f81888c975f7a.zip
Initial commit
Diffstat (limited to 'wolfcrypt/src/tfm.c')
-rw-r--r--wolfcrypt/src/tfm.c5068
1 files changed, 5068 insertions, 0 deletions
diff --git a/wolfcrypt/src/tfm.c b/wolfcrypt/src/tfm.c
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+/* tfm.c
+ *
+ * Copyright (C) 2006-2020 wolfSSL Inc.
+ *
+ * This file is part of wolfSSL.
+ *
+ * wolfSSL is free software; you can redistribute it and/or modify
+ * it under the terms of 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.
+ *
+ * wolfSSL 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 a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
+ */
+
+
+
+/*
+ * Based on public domain TomsFastMath 0.10 by Tom St Denis, [email protected],
+ * http://math.libtomcrypt.com
+ */
+
+/**
+ * Edited by Moises Guimaraes ([email protected])
+ * to fit wolfSSL's needs.
+ */
+
+#ifdef HAVE_CONFIG_H
+ #include <config.h>
+#endif
+
+/* in case user set USE_FAST_MATH there */
+#include <wolfssl/wolfcrypt/settings.h>
+#ifdef NO_INLINE
+ #include <wolfssl/wolfcrypt/misc.h>
+#else
+ #define WOLFSSL_MISC_INCLUDED
+ #include <wolfcrypt/src/misc.c>
+#endif
+
+#ifdef USE_FAST_MATH
+
+#include <wolfssl/wolfcrypt/random.h>
+#include <wolfssl/wolfcrypt/tfm.h>
+#include <wolfcrypt/src/asm.c> /* will define asm MACROS or C ones */
+#include <wolfssl/wolfcrypt/wolfmath.h> /* common functions */
+
+#if defined(FREESCALE_LTC_TFM)
+ #include <wolfssl/wolfcrypt/port/nxp/ksdk_port.h>
+#endif
+#ifdef WOLFSSL_DEBUG_MATH
+ #include <stdio.h>
+#endif
+
+#ifdef USE_WINDOWS_API
+ #pragma warning(disable:4127)
+ /* Disables the warning:
+ * 4127: conditional expression is constant
+ * in this file.
+ */
+#endif
+
+#if defined(WOLFSSL_HAVE_SP_RSA) || defined(WOLFSSL_HAVE_SP_DH)
+#ifdef __cplusplus
+ extern "C" {
+#endif
+WOLFSSL_LOCAL int sp_ModExp_1024(mp_int* base, mp_int* exp, mp_int* mod,
+ mp_int* res);
+WOLFSSL_LOCAL int sp_ModExp_1536(mp_int* base, mp_int* exp, mp_int* mod,
+ mp_int* res);
+WOLFSSL_LOCAL int sp_ModExp_2048(mp_int* base, mp_int* exp, mp_int* mod,
+ mp_int* res);
+WOLFSSL_LOCAL int sp_ModExp_3072(mp_int* base, mp_int* exp, mp_int* mod,
+ mp_int* res);
+WOLFSSL_LOCAL int sp_ModExp_4096(mp_int* base, mp_int* exp, mp_int* mod,
+ mp_int* res);
+#ifdef __cplusplus
+ } /* extern "C" */
+#endif
+#endif
+
+
+#ifndef WOLFSSL_SP_MATH
+/* math settings check */
+word32 CheckRunTimeSettings(void)
+{
+ return CTC_SETTINGS;
+}
+#endif
+
+/* math settings size check */
+word32 CheckRunTimeFastMath(void)
+{
+ return FP_SIZE;
+}
+
+
+/* Functions */
+
+void fp_add(fp_int *a, fp_int *b, fp_int *c)
+{
+ int sa, sb;
+
+ /* get sign of both inputs */
+ sa = a->sign;
+ sb = b->sign;
+
+ /* handle two cases, not four */
+ if (sa == sb) {
+ /* both positive or both negative */
+ /* add their magnitudes, copy the sign */
+ c->sign = sa;
+ s_fp_add (a, b, c);
+ } else {
+ /* one positive, the other negative */
+ /* subtract the one with the greater magnitude from */
+ /* the one of the lesser magnitude. The result gets */
+ /* the sign of the one with the greater magnitude. */
+ if (fp_cmp_mag (a, b) == FP_LT) {
+ c->sign = sb;
+ s_fp_sub (b, a, c);
+ } else {
+ c->sign = sa;
+ s_fp_sub (a, b, c);
+ }
+ }
+}
+
+/* unsigned addition */
+void s_fp_add(fp_int *a, fp_int *b, fp_int *c)
+{
+ int x, y, oldused;
+ fp_word t;
+
+ y = MAX(a->used, b->used);
+ oldused = MIN(c->used, FP_SIZE); /* help static analysis w/ largest size */
+ c->used = y;
+
+ t = 0;
+ for (x = 0; x < y; x++) {
+ t += ((fp_word)a->dp[x]) + ((fp_word)b->dp[x]);
+ c->dp[x] = (fp_digit)t;
+ t >>= DIGIT_BIT;
+ }
+ if (t != 0 && x < FP_SIZE) {
+ c->dp[c->used++] = (fp_digit)t;
+ ++x;
+ }
+
+ c->used = x;
+
+ /* zero any excess digits on the destination that we didn't write to */
+ for (; x < oldused; x++) {
+ c->dp[x] = 0;
+ }
+ fp_clamp(c);
+}
+
+/* c = a - b */
+void fp_sub(fp_int *a, fp_int *b, fp_int *c)
+{
+ int sa, sb;
+
+ sa = a->sign;
+ sb = b->sign;
+
+ if (sa != sb) {
+ /* subtract a negative from a positive, OR */
+ /* subtract a positive from a negative. */
+ /* In either case, ADD their magnitudes, */
+ /* and use the sign of the first number. */
+ c->sign = sa;
+ s_fp_add (a, b, c);
+ } else {
+ /* subtract a positive from a positive, OR */
+ /* subtract a negative from a negative. */
+ /* First, take the difference between their */
+ /* magnitudes, then... */
+ if (fp_cmp_mag (a, b) != FP_LT) {
+ /* Copy the sign from the first */
+ c->sign = sa;
+ /* The first has a larger or equal magnitude */
+ s_fp_sub (a, b, c);
+ } else {
+ /* The result has the *opposite* sign from */
+ /* the first number. */
+ c->sign = (sa == FP_ZPOS) ? FP_NEG : FP_ZPOS;
+ /* The second has a larger magnitude */
+ s_fp_sub (b, a, c);
+ }
+ }
+}
+
+/* unsigned subtraction ||a|| >= ||b|| ALWAYS! */
+void s_fp_sub(fp_int *a, fp_int *b, fp_int *c)
+{
+ int x, oldbused, oldused;
+ fp_word t;
+
+ oldused = c->used;
+ oldbused = b->used;
+ c->used = a->used;
+ t = 0;
+ for (x = 0; x < oldbused; x++) {
+ t = ((fp_word)a->dp[x]) - (((fp_word)b->dp[x]) + t);
+ c->dp[x] = (fp_digit)t;
+ t = (t >> DIGIT_BIT)&1;
+ }
+ for (; x < a->used; x++) {
+ t = ((fp_word)a->dp[x]) - t;
+ c->dp[x] = (fp_digit)t;
+ t = (t >> DIGIT_BIT)&1;
+ }
+
+ /* zero any excess digits on the destination that we didn't write to */
+ for (; x < oldused; x++) {
+ c->dp[x] = 0;
+ }
+ fp_clamp(c);
+}
+
+/* c = a * b */
+int fp_mul(fp_int *A, fp_int *B, fp_int *C)
+{
+ int ret = 0;
+ int y, yy, oldused;
+
+#if defined(WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI) && \
+ !defined(NO_WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI)
+ ret = esp_mp_mul(A, B, C);
+ if(ret != -2) return ret;
+#endif
+
+ oldused = C->used;
+
+ y = MAX(A->used, B->used);
+ yy = MIN(A->used, B->used);
+
+ /* call generic if we're out of range */
+ if (y + yy > FP_SIZE) {
+ ret = fp_mul_comba(A, B, C);
+ goto clean;
+ }
+
+ /* pick a comba (unrolled 4/8/16/32 x or rolled) based on the size
+ of the largest input. We also want to avoid doing excess mults if the
+ inputs are not close to the next power of two. That is, for example,
+ if say y=17 then we would do (32-17)^2 = 225 unneeded multiplications
+ */
+
+#if defined(TFM_MUL3) && FP_SIZE >= 6
+ if (y <= 3) {
+ ret = fp_mul_comba3(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL4) && FP_SIZE >= 8
+ if (y == 4) {
+ ret = fp_mul_comba4(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL6) && FP_SIZE >= 12
+ if (y <= 6) {
+ ret = fp_mul_comba6(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL7) && FP_SIZE >= 14
+ if (y == 7) {
+ ret = fp_mul_comba7(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL8) && FP_SIZE >= 16
+ if (y == 8) {
+ ret = fp_mul_comba8(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL9) && FP_SIZE >= 18
+ if (y == 9) {
+ ret = fp_mul_comba9(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL12) && FP_SIZE >= 24
+ if (y <= 12) {
+ ret = fp_mul_comba12(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL17) && FP_SIZE >= 34
+ if (y <= 17) {
+ ret = fp_mul_comba17(A,B,C);
+ goto clean;
+ }
+#endif
+
+#if defined(TFM_SMALL_SET) && FP_SIZE >= 32
+ if (y <= 16) {
+ ret = fp_mul_comba_small(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL20) && FP_SIZE >= 40
+ if (y <= 20) {
+ ret = fp_mul_comba20(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL24) && FP_SIZE >= 48
+ if (yy >= 16 && y <= 24) {
+ ret = fp_mul_comba24(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL28) && FP_SIZE >= 56
+ if (yy >= 20 && y <= 28) {
+ ret = fp_mul_comba28(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL32) && FP_SIZE >= 64
+ if (yy >= 24 && y <= 32) {
+ ret = fp_mul_comba32(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL48) && FP_SIZE >= 96
+ if (yy >= 40 && y <= 48) {
+ ret = fp_mul_comba48(A,B,C);
+ goto clean;
+ }
+#endif
+#if defined(TFM_MUL64) && FP_SIZE >= 128
+ if (yy >= 56 && y <= 64) {
+ ret = fp_mul_comba64(A,B,C);
+ goto clean;
+ }
+#endif
+ ret = fp_mul_comba(A,B,C);
+
+clean:
+ /* zero any excess digits on the destination that we didn't write to */
+ for (y = C->used; y >= 0 && y < oldused; y++) {
+ C->dp[y] = 0;
+ }
+
+ return ret;
+}
+
+void fp_mul_2(fp_int * a, fp_int * b)
+{
+ int x, oldused;
+
+ oldused = b->used;
+ b->used = a->used;
+
+ {
+ fp_digit r, rr, *tmpa, *tmpb;
+
+ /* alias for source */
+ tmpa = a->dp;
+
+ /* alias for dest */
+ tmpb = b->dp;
+
+ /* carry */
+ r = 0;
+ for (x = 0; x < a->used; x++) {
+
+ /* get what will be the *next* carry bit from the
+ * MSB of the current digit
+ */
+ rr = *tmpa >> ((fp_digit)(DIGIT_BIT - 1));
+
+ /* now shift up this digit, add in the carry [from the previous] */
+ *tmpb++ = ((*tmpa++ << ((fp_digit)1)) | r);
+
+ /* copy the carry that would be from the source
+ * digit into the next iteration
+ */
+ r = rr;
+ }
+
+ /* new leading digit? */
+ if (r != 0 && b->used != (FP_SIZE-1)) {
+ /* add a MSB which is always 1 at this point */
+ *tmpb = 1;
+ ++(b->used);
+ }
+
+ /* zero any excess digits on the destination that we didn't write to */
+ tmpb = b->dp + b->used;
+ for (x = b->used; x < oldused; x++) {
+ *tmpb++ = 0;
+ }
+ }
+ b->sign = a->sign;
+}
+
+/* c = a * b */
+void fp_mul_d(fp_int *a, fp_digit b, fp_int *c)
+{
+ fp_word w;
+ int x, oldused;
+
+ oldused = c->used;
+ c->used = a->used;
+ c->sign = a->sign;
+ w = 0;
+ for (x = 0; x < a->used; x++) {
+ w = ((fp_word)a->dp[x]) * ((fp_word)b) + w;
+ c->dp[x] = (fp_digit)w;
+ w = w >> DIGIT_BIT;
+ }
+ if (w != 0 && (a->used != FP_SIZE)) {
+ c->dp[c->used++] = (fp_digit) w;
+ ++x;
+ }
+
+ /* zero any excess digits on the destination that we didn't write to */
+ /* also checking FP_SIZE here for static analysis */
+ for (; x < oldused && x < FP_SIZE; x++) {
+ c->dp[x] = 0;
+ }
+ fp_clamp(c);
+}
+
+/* c = a * 2**d */
+void fp_mul_2d(fp_int *a, int b, fp_int *c)
+{
+ fp_digit carry, carrytmp, shift;
+ int x;
+
+ /* copy it */
+ fp_copy(a, c);
+
+ /* handle whole digits */
+ if (b >= DIGIT_BIT) {
+ fp_lshd(c, b/DIGIT_BIT);
+ }
+ b %= DIGIT_BIT;
+
+ /* shift the digits */
+ if (b != 0) {
+ carry = 0;
+ shift = DIGIT_BIT - b;
+ for (x = 0; x < c->used; x++) {
+ carrytmp = c->dp[x] >> shift;
+ c->dp[x] = (c->dp[x] << b) + carry;
+ carry = carrytmp;
+ }
+ /* store last carry if room */
+ if (carry && x < FP_SIZE) {
+ c->dp[c->used++] = carry;
+ }
+ }
+ fp_clamp(c);
+}
+
+/* generic PxQ multiplier */
+#if defined(HAVE_INTEL_MULX)
+
+WC_INLINE static int fp_mul_comba_mulx(fp_int *A, fp_int *B, fp_int *C)
+
+{
+ int ix, iy, iz, pa;
+ fp_int *dst;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int tmp[1];
+#else
+ fp_int *tmp;
+#endif
+
+ /* Variables used but not seen by cppcheck. */
+ (void)ix; (void)iy; (void)iz;
+
+#ifdef WOLFSSL_SMALL_STACK
+ tmp = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (tmp == NULL)
+ return FP_MEM;
+#endif
+
+ /* get size of output and trim */
+ pa = A->used + B->used;
+ if (pa >= FP_SIZE) {
+ pa = FP_SIZE-1;
+ }
+
+ /* Always take branch to use tmp variable. This avoids a cache attack for
+ * determining if C equals A */
+ if (1) {
+ fp_init(tmp);
+ dst = tmp;
+ }
+
+ TFM_INTEL_MUL_COMBA(A, B, dst) ;
+
+ dst->used = pa;
+ dst->sign = A->sign ^ B->sign;
+ fp_clamp(dst);
+ fp_copy(dst, C);
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(tmp, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+
+ return FP_OKAY;
+}
+#endif
+
+int fp_mul_comba(fp_int *A, fp_int *B, fp_int *C)
+{
+ int ret = 0;
+ int ix, iy, iz, tx, ty, pa;
+ fp_digit c0, c1, c2, *tmpx, *tmpy;
+ fp_int *dst;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int tmp[1];
+#else
+ fp_int *tmp;
+#endif
+
+ IF_HAVE_INTEL_MULX(ret = fp_mul_comba_mulx(A, B, C), return ret) ;
+
+#ifdef WOLFSSL_SMALL_STACK
+ tmp = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (tmp == NULL)
+ return FP_MEM;
+#endif
+
+ COMBA_START;
+ COMBA_CLEAR;
+
+ /* get size of output and trim */
+ pa = A->used + B->used;
+ if (pa >= FP_SIZE) {
+ pa = FP_SIZE-1;
+ }
+
+ /* Always take branch to use tmp variable. This avoids a cache attack for
+ * determining if C equals A */
+ if (1) {
+ fp_init(tmp);
+ dst = tmp;
+ }
+
+ for (ix = 0; ix < pa; ix++) {
+ /* get offsets into the two bignums */
+ ty = MIN(ix, (B->used > 0 ? B->used - 1 : 0));
+ tx = ix - ty;
+
+ /* setup temp aliases */
+ tmpx = A->dp + tx;
+ tmpy = B->dp + ty;
+
+ /* this is the number of times the loop will iterate, essentially its
+ while (tx++ < a->used && ty-- >= 0) { ... }
+ */
+ iy = MIN(A->used-tx, ty+1);
+
+ /* execute loop */
+ COMBA_FORWARD;
+ for (iz = 0; iz < iy; ++iz) {
+ fp_digit _tmpx = *tmpx++;
+ fp_digit _tmpy = *tmpy--;
+ MULADD(_tmpx, _tmpy);
+ }
+
+ /* store term */
+ COMBA_STORE(dst->dp[ix]);
+ }
+ COMBA_FINI;
+
+ dst->used = pa;
+ dst->sign = A->sign ^ B->sign;
+ fp_clamp(dst);
+ fp_copy(dst, C);
+
+ /* Variables used but not seen by cppcheck. */
+ (void)c0; (void)c1; (void)c2;
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(tmp, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return ret;
+}
+
+/* a/b => cb + d == a */
+int fp_div(fp_int *a, fp_int *b, fp_int *c, fp_int *d)
+{
+ int n, t, i, norm, neg;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int q[1], x[1], y[1], t1[1], t2[1];
+#else
+ fp_int *q, *x, *y, *t1, *t2;
+#endif
+
+ /* is divisor zero ? */
+ if (fp_iszero (b) == FP_YES) {
+ return FP_VAL;
+ }
+
+ /* if a < b then q=0, r = a */
+ if (fp_cmp_mag (a, b) == FP_LT) {
+ if (d != NULL) {
+ fp_copy (a, d);
+ }
+ if (c != NULL) {
+ fp_zero (c);
+ }
+ return FP_OKAY;
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ q = (fp_int*)XMALLOC(sizeof(fp_int) * 5, NULL, DYNAMIC_TYPE_BIGINT);
+ if (q == NULL) {
+ return FP_MEM;
+ }
+ x = &q[1]; y = &q[2]; t1 = &q[3]; t2 = &q[4];
+#endif
+
+ fp_init(q);
+ q->used = a->used + 2;
+
+ fp_init(t1);
+ fp_init(t2);
+ fp_init_copy(x, a);
+ fp_init_copy(y, b);
+
+ /* fix the sign */
+ neg = (a->sign == b->sign) ? FP_ZPOS : FP_NEG;
+ x->sign = y->sign = FP_ZPOS;
+
+ /* normalize both x and y, ensure that y >= b/2, [b == 2**DIGIT_BIT] */
+ norm = fp_count_bits(y) % DIGIT_BIT;
+ if (norm < (int)(DIGIT_BIT-1)) {
+ norm = (DIGIT_BIT-1) - norm;
+ fp_mul_2d (x, norm, x);
+ fp_mul_2d (y, norm, y);
+ } else {
+ norm = 0;
+ }
+
+ /* note hac does 0 based, so if used==5 then its 0,1,2,3,4, e.g. use 4 */
+ n = x->used - 1;
+ t = y->used - 1;
+
+ /* while (x >= y*b**n-t) do { q[n-t] += 1; x -= y*b**{n-t} } */
+ fp_lshd (y, n - t); /* y = y*b**{n-t} */
+
+ while (fp_cmp (x, y) != FP_LT) {
+ ++(q->dp[n - t]);
+ fp_sub (x, y, x);
+ }
+
+ /* reset y by shifting it back down */
+ fp_rshd (y, n - t);
+
+ /* step 3. for i from n down to (t + 1) */
+ for (i = n; i >= (t + 1); i--) {
+ if (i > x->used) {
+ continue;
+ }
+
+ /* step 3.1 if xi == yt then set q{i-t-1} to b-1,
+ * otherwise set q{i-t-1} to (xi*b + x{i-1})/yt */
+ if (x->dp[i] == y->dp[t]) {
+ q->dp[i - t - 1] = (fp_digit) ((((fp_word)1) << DIGIT_BIT) - 1);
+ } else {
+ fp_word tmp;
+ tmp = ((fp_word) x->dp[i]) << ((fp_word) DIGIT_BIT);
+ tmp |= ((fp_word) x->dp[i - 1]);
+ tmp /= ((fp_word)y->dp[t]);
+ q->dp[i - t - 1] = (fp_digit) (tmp);
+ }
+
+ /* while (q{i-t-1} * (yt * b + y{t-1})) >
+ xi * b**2 + xi-1 * b + xi-2
+
+ do q{i-t-1} -= 1;
+ */
+ q->dp[i - t - 1] = (q->dp[i - t - 1] + 1);
+ do {
+ q->dp[i - t - 1] = (q->dp[i - t - 1] - 1);
+
+ /* find left hand */
+ fp_zero (t1);
+ t1->dp[0] = (t - 1 < 0) ? 0 : y->dp[t - 1];
+ t1->dp[1] = y->dp[t];
+ t1->used = 2;
+ fp_mul_d (t1, q->dp[i - t - 1], t1);
+
+ /* find right hand */
+ t2->dp[0] = (i - 2 < 0) ? 0 : x->dp[i - 2];
+ t2->dp[1] = (i - 1 < 0) ? 0 : x->dp[i - 1];
+ t2->dp[2] = x->dp[i];
+ t2->used = 3;
+ } while (fp_cmp_mag(t1, t2) == FP_GT);
+
+ /* step 3.3 x = x - q{i-t-1} * y * b**{i-t-1} */
+ fp_mul_d (y, q->dp[i - t - 1], t1);
+ fp_lshd (t1, i - t - 1);
+ fp_sub (x, t1, x);
+
+ /* if x < 0 then { x = x + y*b**{i-t-1}; q{i-t-1} -= 1; } */
+ if (x->sign == FP_NEG) {
+ fp_copy (y, t1);
+ fp_lshd (t1, i - t - 1);
+ fp_add (x, t1, x);
+ q->dp[i - t - 1] = q->dp[i - t - 1] - 1;
+ }
+ }
+
+ /* now q is the quotient and x is the remainder
+ * [which we have to normalize]
+ */
+
+ /* get sign before writing to c */
+ x->sign = x->used == 0 ? FP_ZPOS : a->sign;
+
+ if (c != NULL) {
+ fp_clamp (q);
+ fp_copy (q, c);
+ c->sign = neg;
+ }
+
+ if (d != NULL) {
+ fp_div_2d (x, norm, x, NULL);
+
+ /* zero any excess digits on the destination that we didn't write to */
+ for (i = b->used; i < x->used; i++) {
+ x->dp[i] = 0;
+ }
+ fp_clamp(x);
+ fp_copy (x, d);
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(q, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+/* b = a/2 */
+void fp_div_2(fp_int * a, fp_int * b)
+{
+ int x, oldused;
+
+ oldused = b->used;
+ b->used = a->used;
+ {
+ fp_digit r, rr, *tmpa, *tmpb;
+
+ /* source alias */
+ tmpa = a->dp + b->used - 1;
+
+ /* dest alias */
+ tmpb = b->dp + b->used - 1;
+
+ /* carry */
+ r = 0;
+ for (x = b->used - 1; x >= 0; x--) {
+ /* get the carry for the next iteration */
+ rr = *tmpa & 1;
+
+ /* shift the current digit, add in carry and store */
+ *tmpb-- = (*tmpa-- >> 1) | (r << (DIGIT_BIT - 1));
+
+ /* forward carry to next iteration */
+ r = rr;
+ }
+
+ /* zero any excess digits on the destination that we didn't write to */
+ tmpb = b->dp + b->used;
+ for (x = b->used; x < oldused; x++) {
+ *tmpb++ = 0;
+ }
+ }
+ b->sign = a->sign;
+ fp_clamp (b);
+}
+
+/* c = a / 2**b */
+void fp_div_2d(fp_int *a, int b, fp_int *c, fp_int *d)
+{
+ int D;
+
+ /* if the shift count is <= 0 then we do no work */
+ if (b <= 0) {
+ fp_copy (a, c);
+ if (d != NULL) {
+ fp_zero (d);
+ }
+ return;
+ }
+
+ /* get the remainder before a is changed in calculating c */
+ if (a == c && d != NULL) {
+ fp_mod_2d (a, b, d);
+ }
+
+ /* copy */
+ fp_copy(a, c);
+
+ /* shift by as many digits in the bit count */
+ if (b >= (int)DIGIT_BIT) {
+ fp_rshd (c, b / DIGIT_BIT);
+ }
+
+ /* shift any bit count < DIGIT_BIT */
+ D = (b % DIGIT_BIT);
+ if (D != 0) {
+ fp_rshb(c, D);
+ }
+
+ /* get the remainder if a is not changed in calculating c */
+ if (a != c && d != NULL) {
+ fp_mod_2d (a, b, d);
+ }
+
+ fp_clamp (c);
+}
+
+/* c = a mod b, 0 <= c < b */
+int fp_mod(fp_int *a, fp_int *b, fp_int *c)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+ int err;
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init(t);
+ err = fp_div(a, b, NULL, t);
+ if (err == FP_OKAY) {
+ if (t->sign != b->sign) {
+ fp_add(t, b, c);
+ } else {
+ fp_copy(t, c);
+ }
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return err;
+}
+
+/* c = a mod 2**d */
+void fp_mod_2d(fp_int *a, int b, fp_int *c)
+{
+ int x;
+
+ /* zero if count less than or equal to zero */
+ if (b <= 0) {
+ fp_zero(c);
+ return;
+ }
+
+ /* get copy of input */
+ fp_copy(a, c);
+
+ /* if 2**d is larger than we just return */
+ if (b >= (DIGIT_BIT * a->used)) {
+ return;
+ }
+
+ /* zero digits above the last digit of the modulus */
+ for (x = (b / DIGIT_BIT) + ((b % DIGIT_BIT) == 0 ? 0 : 1); x < c->used; x++) {
+ c->dp[x] = 0;
+ }
+ /* clear the digit that is not completely outside/inside the modulus */
+ c->dp[b / DIGIT_BIT] &= ~((fp_digit)0) >> (DIGIT_BIT - b);
+ fp_clamp (c);
+}
+
+static int fp_invmod_slow (fp_int * a, fp_int * b, fp_int * c)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int x[1], y[1], u[1], v[1], A[1], B[1], C[1], D[1];
+#else
+ fp_int *x, *y, *u, *v, *A, *B, *C, *D;
+#endif
+ int err;
+
+ /* b cannot be negative */
+ if (b->sign == FP_NEG || fp_iszero(b) == FP_YES) {
+ return FP_VAL;
+ }
+ if (fp_iszero(a) == FP_YES) {
+ return FP_VAL;
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ x = (fp_int*)XMALLOC(sizeof(fp_int) * 8, NULL, DYNAMIC_TYPE_BIGINT);
+ if (x == NULL) {
+ return FP_MEM;
+ }
+ y = &x[1]; u = &x[2]; v = &x[3]; A = &x[4]; B = &x[5]; C = &x[6]; D = &x[7];
+#endif
+
+ /* init temps */
+ fp_init(x); fp_init(y);
+ fp_init(u); fp_init(v);
+ fp_init(A); fp_init(B);
+ fp_init(C); fp_init(D);
+
+ /* x = a, y = b */
+ if ((err = fp_mod(a, b, x)) != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(x, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+ }
+ fp_copy(b, y);
+
+ /* 2. [modified] if x,y are both even then return an error! */
+ if (fp_iseven(x) == FP_YES && fp_iseven(y) == FP_YES) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(x, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return FP_VAL;
+ }
+
+ /* 3. u=x, v=y, A=1, B=0, C=0,D=1 */
+ fp_copy (x, u);
+ fp_copy (y, v);
+ fp_set (A, 1);
+ fp_set (D, 1);
+
+top:
+ /* 4. while u is even do */
+ while (fp_iseven (u) == FP_YES) {
+ /* 4.1 u = u/2 */
+ fp_div_2 (u, u);
+
+ /* 4.2 if A or B is odd then */
+ if (fp_isodd (A) == FP_YES || fp_isodd (B) == FP_YES) {
+ /* A = (A+y)/2, B = (B-x)/2 */
+ fp_add (A, y, A);
+ fp_sub (B, x, B);
+ }
+ /* A = A/2, B = B/2 */
+ fp_div_2 (A, A);
+ fp_div_2 (B, B);
+ }
+
+ /* 5. while v is even do */
+ while (fp_iseven (v) == FP_YES) {
+ /* 5.1 v = v/2 */
+ fp_div_2 (v, v);
+
+ /* 5.2 if C or D is odd then */
+ if (fp_isodd (C) == FP_YES || fp_isodd (D) == FP_YES) {
+ /* C = (C+y)/2, D = (D-x)/2 */
+ fp_add (C, y, C);
+ fp_sub (D, x, D);
+ }
+ /* C = C/2, D = D/2 */
+ fp_div_2 (C, C);
+ fp_div_2 (D, D);
+ }
+
+ /* 6. if u >= v then */
+ if (fp_cmp (u, v) != FP_LT) {
+ /* u = u - v, A = A - C, B = B - D */
+ fp_sub (u, v, u);
+ fp_sub (A, C, A);
+ fp_sub (B, D, B);
+ } else {
+ /* v - v - u, C = C - A, D = D - B */
+ fp_sub (v, u, v);
+ fp_sub (C, A, C);
+ fp_sub (D, B, D);
+ }
+
+ /* if not zero goto step 4 */
+ if (fp_iszero (u) == FP_NO)
+ goto top;
+
+ /* now a = C, b = D, gcd == g*v */
+
+ /* if v != 1 then there is no inverse */
+ if (fp_cmp_d (v, 1) != FP_EQ) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(x, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return FP_VAL;
+ }
+
+ /* if its too low */
+ while (fp_cmp_d(C, 0) == FP_LT) {
+ fp_add(C, b, C);
+ }
+
+ /* too big */
+ while (fp_cmp_mag(C, b) != FP_LT) {
+ fp_sub(C, b, C);
+ }
+
+ /* C is now the inverse */
+ fp_copy(C, c);
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(x, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+/* c = 1/a (mod b) for odd b only */
+int fp_invmod(fp_int *a, fp_int *b, fp_int *c)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int x[1], y[1], u[1], v[1], B[1], D[1];
+#else
+ fp_int *x, *y, *u, *v, *B, *D;
+#endif
+ int neg;
+ int err;
+
+ if (b->sign == FP_NEG || fp_iszero(b) == FP_YES) {
+ return FP_VAL;
+ }
+
+ /* [modified] sanity check on "a" */
+ if (fp_iszero(a) == FP_YES) {
+ return FP_VAL; /* can not divide by 0 here */
+ }
+
+ /* 2. [modified] b must be odd */
+ if (fp_iseven(b) == FP_YES) {
+ return fp_invmod_slow(a,b,c);
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ x = (fp_int*)XMALLOC(sizeof(fp_int) * 6, NULL, DYNAMIC_TYPE_BIGINT);
+ if (x == NULL) {
+ return FP_MEM;
+ }
+ y = &x[1]; u = &x[2]; v = &x[3]; B = &x[4]; D = &x[5];
+#endif
+
+ /* init all our temps */
+ fp_init(x); fp_init(y);
+ fp_init(u); fp_init(v);
+ fp_init(B); fp_init(D);
+
+ if (fp_cmp(a, b) != MP_LT) {
+ err = mp_mod(a, b, y);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(x, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+ }
+ a = y;
+ }
+
+ if (fp_iszero(a) == FP_YES) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(x, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return FP_VAL;
+ }
+
+ /* x == modulus, y == value to invert */
+ fp_copy(b, x);
+
+ /* we need y = |a| */
+ fp_abs(a, y);
+
+ /* 3. u=x, v=y, A=1, B=0, C=0,D=1 */
+ fp_copy(x, u);
+ fp_copy(y, v);
+ fp_set (D, 1);
+
+top:
+ /* 4. while u is even do */
+ while (fp_iseven (u) == FP_YES) {
+ /* 4.1 u = u/2 */
+ fp_div_2 (u, u);
+
+ /* 4.2 if B is odd then */
+ if (fp_isodd (B) == FP_YES) {
+ fp_sub (B, x, B);
+ }
+ /* B = B/2 */
+ fp_div_2 (B, B);
+ }
+
+ /* 5. while v is even do */
+ while (fp_iseven (v) == FP_YES) {
+ /* 5.1 v = v/2 */
+ fp_div_2 (v, v);
+
+ /* 5.2 if D is odd then */
+ if (fp_isodd (D) == FP_YES) {
+ /* D = (D-x)/2 */
+ fp_sub (D, x, D);
+ }
+ /* D = D/2 */
+ fp_div_2 (D, D);
+ }
+
+ /* 6. if u >= v then */
+ if (fp_cmp (u, v) != FP_LT) {
+ /* u = u - v, B = B - D */
+ fp_sub (u, v, u);
+ fp_sub (B, D, B);
+ } else {
+ /* v - v - u, D = D - B */
+ fp_sub (v, u, v);
+ fp_sub (D, B, D);
+ }
+
+ /* if not zero goto step 4 */
+ if (fp_iszero (u) == FP_NO) {
+ goto top;
+ }
+
+ /* now a = C, b = D, gcd == g*v */
+
+ /* if v != 1 then there is no inverse */
+ if (fp_cmp_d (v, 1) != FP_EQ) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(x, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return FP_VAL;
+ }
+
+ /* b is now the inverse */
+ neg = a->sign;
+ while (D->sign == FP_NEG) {
+ fp_add (D, b, D);
+ }
+ /* too big */
+ while (fp_cmp_mag(D, b) != FP_LT) {
+ fp_sub(D, b, D);
+ }
+ fp_copy (D, c);
+ c->sign = neg;
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(x, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+#define CT_INV_MOD_PRE_CNT 8
+
+/* modulus (b) must be greater than 2 and a prime */
+int fp_invmod_mont_ct(fp_int *a, fp_int *b, fp_int *c, fp_digit mp)
+{
+ int i, j;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1], e[1];
+ fp_int pre[CT_INV_MOD_PRE_CNT];
+#else
+ fp_int* t;
+ fp_int* e;
+ fp_int* pre;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int) * (2 + CT_INV_MOD_PRE_CNT), NULL,
+ DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+ e = t + 1;
+ pre = t + 2;
+#endif
+
+ fp_init(t);
+ fp_init(e);
+
+ fp_init(&pre[0]);
+ fp_copy(a, &pre[0]);
+ for (i = 1; i < CT_INV_MOD_PRE_CNT; i++) {
+ fp_init(&pre[i]);
+ fp_sqr(&pre[i-1], &pre[i]);
+ fp_montgomery_reduce(&pre[i], b, mp);
+ fp_mul(&pre[i], a, &pre[i]);
+ fp_montgomery_reduce(&pre[i], b, mp);
+ }
+
+ fp_sub_d(b, 2, e);
+ /* Highest bit is always set. */
+ for (i = fp_count_bits(e)-2, j = 1; i >= 0; i--, j++) {
+ if (!fp_is_bit_set(e, i) || j == CT_INV_MOD_PRE_CNT)
+ break;
+ }
+ fp_copy(&pre[j-1], t);
+ for (j = 0; i >= 0; i--) {
+ int set = fp_is_bit_set(e, i);
+
+ if ((j == CT_INV_MOD_PRE_CNT) || (!set && j > 0)) {
+ fp_mul(t, &pre[j-1], t);
+ fp_montgomery_reduce(t, b, mp);
+ j = 0;
+ }
+ fp_sqr(t, t);
+ fp_montgomery_reduce(t, b, mp);
+ j += set;
+ }
+ if (j > 0) {
+ fp_mul(t, &pre[j-1], c);
+ fp_montgomery_reduce(c, b, mp);
+ }
+ else
+ fp_copy(t, c);
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+/* d = a * b (mod c) */
+int fp_mulmod(fp_int *a, fp_int *b, fp_int *c, fp_int *d)
+{
+ int err;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init(t);
+ err = fp_mul(a, b, t);
+ if (err == FP_OKAY) {
+ #if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ if (d->size < FP_SIZE) {
+ err = fp_mod(t, c, t);
+ fp_copy(t, d);
+ } else
+ #endif
+ {
+ err = fp_mod(t, c, d);
+ }
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return err;
+}
+
+/* d = a - b (mod c) */
+int fp_submod(fp_int *a, fp_int *b, fp_int *c, fp_int *d)
+{
+ int err;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init(t);
+ fp_sub(a, b, t);
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ if (d->size < FP_SIZE) {
+ err = fp_mod(t, c, t);
+ fp_copy(t, d);
+ } else
+#endif
+ {
+ err = fp_mod(t, c, d);
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return err;
+}
+
+/* d = a + b (mod c) */
+int fp_addmod(fp_int *a, fp_int *b, fp_int *c, fp_int *d)
+{
+ int err;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init(t);
+ fp_add(a, b, t);
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ if (d->size < FP_SIZE) {
+ err = fp_mod(t, c, t);
+ fp_copy(t, d);
+ } else
+#endif
+ {
+ err = fp_mod(t, c, d);
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return err;
+}
+
+#ifdef TFM_TIMING_RESISTANT
+
+#ifdef WC_RSA_NONBLOCK
+
+#ifdef WC_RSA_NONBLOCK_TIME
+ /* User can override the check-time at build-time using the
+ * FP_EXPTMOD_NB_CHECKTIME macro to define your own function */
+ #ifndef FP_EXPTMOD_NB_CHECKTIME
+ /* instruction count for each type of operation */
+ /* array lookup is using TFM_EXPTMOD_NB_* states */
+ static const word32 exptModNbInst[TFM_EXPTMOD_NB_COUNT] = {
+ #ifdef TFM_PPC32
+ #ifdef _DEBUG
+ 11098, 8701, 3971, 178394, 858093, 1040, 822, 178056, 181574, 90883, 184339, 236813
+ #else
+ 7050, 2554, 3187, 43178, 200422, 384, 275, 43024, 43550, 30450, 46270, 61376
+ #endif
+ #elif defined(TFM_X86_64)
+ #ifdef _DEBUG
+ 954, 2377, 858, 19027, 90840, 287, 407, 20140, 7874, 11385, 8005, 6151
+ #else
+ 765, 1007, 771, 5216, 34993, 248, 193, 4975, 4201, 3947, 4275, 3811
+ #endif
+ #else /* software only fast math */
+ #ifdef _DEBUG
+ 798, 2245, 802, 16657, 66920, 352, 186, 16997, 16145, 12789, 16742, 15006
+ #else
+ 775, 1084, 783, 4692, 37510, 207, 183, 4374, 4392, 3097, 4442, 4079
+ #endif
+ #endif
+ };
+
+ static int fp_exptmod_nb_checktime(exptModNb_t* nb)
+ {
+ word32 totalInst;
+
+ /* if no max time has been set then stop (do not block) */
+ if (nb->maxBlockInst == 0 || nb->state >= TFM_EXPTMOD_NB_COUNT) {
+ return TFM_EXPTMOD_NB_STOP;
+ }
+
+ /* if instruction table not set then use maxBlockInst as simple counter */
+ if (exptModNbInst[nb->state] == 0) {
+ if (++nb->totalInst < nb->maxBlockInst)
+ return TFM_EXPTMOD_NB_CONTINUE;
+
+ nb->totalInst = 0; /* reset counter */
+ return TFM_EXPTMOD_NB_STOP;
+ }
+
+ /* get total instruction count including next operation */
+ totalInst = nb->totalInst + exptModNbInst[nb->state];
+ /* if the next operation can completed within the maximum then continue */
+ if (totalInst <= nb->maxBlockInst) {
+ return TFM_EXPTMOD_NB_CONTINUE;
+ }
+
+ return TFM_EXPTMOD_NB_STOP;
+ }
+ #define FP_EXPTMOD_NB_CHECKTIME(nb) fp_exptmod_nb_checktime((nb))
+ #endif /* !FP_EXPTMOD_NB_CHECKTIME */
+#endif /* WC_RSA_NONBLOCK_TIME */
+
+/* non-blocking version of timing resistant fp_exptmod function */
+/* supports cache resistance */
+int fp_exptmod_nb(exptModNb_t* nb, fp_int* G, fp_int* X, fp_int* P, fp_int* Y)
+{
+ int err, ret = FP_WOULDBLOCK;
+
+ if (nb == NULL)
+ return FP_VAL;
+
+#ifdef WC_RSA_NONBLOCK_TIME
+ nb->totalInst = 0;
+ do {
+ nb->totalInst += exptModNbInst[nb->state];
+#endif
+
+ switch (nb->state) {
+ case TFM_EXPTMOD_NB_INIT:
+ /* now setup montgomery */
+ if ((err = fp_montgomery_setup(P, &nb->mp)) != FP_OKAY) {
+ nb->state = TFM_EXPTMOD_NB_INIT;
+ return err;
+ }
+
+ /* init ints */
+ fp_init(&nb->R[0]);
+ fp_init(&nb->R[1]);
+ #ifndef WC_NO_CACHE_RESISTANT
+ fp_init(&nb->R[2]);
+ #endif
+ nb->state = TFM_EXPTMOD_NB_MONT;
+ break;
+
+ case TFM_EXPTMOD_NB_MONT:
+ /* mod m -> R[0] */
+ fp_montgomery_calc_normalization(&nb->R[0], P);
+
+ nb->state = TFM_EXPTMOD_NB_MONT_RED;
+ break;
+
+ case TFM_EXPTMOD_NB_MONT_RED:
+ /* reduce G -> R[1] */
+ if (fp_cmp_mag(P, G) != FP_GT) {
+ /* G > P so we reduce it first */
+ fp_mod(G, P, &nb->R[1]);
+ } else {
+ fp_copy(G, &nb->R[1]);
+ }
+
+ nb->state = TFM_EXPTMOD_NB_MONT_MUL;
+ break;
+
+ case TFM_EXPTMOD_NB_MONT_MUL:
+ /* G (R[1]) * m (R[0]) */
+ err = fp_mul(&nb->R[1], &nb->R[0], &nb->R[1]);
+ if (err != FP_OKAY) {
+ nb->state = TFM_EXPTMOD_NB_INIT;
+ return err;
+ }
+
+ nb->state = TFM_EXPTMOD_NB_MONT_MOD;
+ break;
+
+ case TFM_EXPTMOD_NB_MONT_MOD:
+ /* mod m */
+ err = fp_div(&nb->R[1], P, NULL, &nb->R[1]);
+ if (err != FP_OKAY) {
+ nb->state = TFM_EXPTMOD_NB_INIT;
+ return err;
+ }
+
+ nb->state = TFM_EXPTMOD_NB_MONT_MODCHK;
+ break;
+
+ case TFM_EXPTMOD_NB_MONT_MODCHK:
+ /* m matches sign of (G * R mod m) */
+ if (nb->R[1].sign != P->sign) {
+ fp_add(&nb->R[1], P, &nb->R[1]);
+ }
+
+ /* set initial mode and bit cnt */
+ nb->bitcnt = 1;
+ nb->buf = 0;
+ nb->digidx = X->used - 1;
+
+ nb->state = TFM_EXPTMOD_NB_NEXT;
+ break;
+
+ case TFM_EXPTMOD_NB_NEXT:
+ /* grab next digit as required */
+ if (--nb->bitcnt == 0) {
+ /* if nb->digidx == -1 we are out of digits so break */
+ if (nb->digidx == -1) {
+ nb->state = TFM_EXPTMOD_NB_RED;
+ break;
+ }
+ /* read next digit and reset nb->bitcnt */
+ nb->buf = X->dp[nb->digidx--];
+ nb->bitcnt = (int)DIGIT_BIT;
+ }
+
+ /* grab the next msb from the exponent */
+ nb->y = (int)(nb->buf >> (DIGIT_BIT - 1)) & 1;
+ nb->buf <<= (fp_digit)1;
+ nb->state = TFM_EXPTMOD_NB_MUL;
+ FALL_THROUGH;
+
+ case TFM_EXPTMOD_NB_MUL:
+ fp_mul(&nb->R[0], &nb->R[1], &nb->R[nb->y^1]);
+ nb->state = TFM_EXPTMOD_NB_MUL_RED;
+ break;
+
+ case TFM_EXPTMOD_NB_MUL_RED:
+ fp_montgomery_reduce(&nb->R[nb->y^1], P, nb->mp);
+ nb->state = TFM_EXPTMOD_NB_SQR;
+ break;
+
+ case TFM_EXPTMOD_NB_SQR:
+ #ifdef WC_NO_CACHE_RESISTANT
+ fp_sqr(&nb->R[nb->y], &nb->R[nb->y]);
+ #else
+ fp_copy((fp_int*) ( ((wolfssl_word)&nb->R[0] & wc_off_on_addr[nb->y^1]) +
+ ((wolfssl_word)&nb->R[1] & wc_off_on_addr[nb->y]) ),
+ &nb->R[2]);
+ fp_sqr(&nb->R[2], &nb->R[2]);
+ #endif /* WC_NO_CACHE_RESISTANT */
+
+ nb->state = TFM_EXPTMOD_NB_SQR_RED;
+ break;
+
+ case TFM_EXPTMOD_NB_SQR_RED:
+ #ifdef WC_NO_CACHE_RESISTANT
+ fp_montgomery_reduce(&nb->R[nb->y], P, nb->mp);
+ #else
+ fp_montgomery_reduce(&nb->R[2], P, nb->mp);
+ fp_copy(&nb->R[2],
+ (fp_int*) ( ((wolfssl_word)&nb->R[0] & wc_off_on_addr[nb->y^1]) +
+ ((wolfssl_word)&nb->R[1] & wc_off_on_addr[nb->y]) ) );
+ #endif /* WC_NO_CACHE_RESISTANT */
+
+ nb->state = TFM_EXPTMOD_NB_NEXT;
+ break;
+
+ case TFM_EXPTMOD_NB_RED:
+ /* final reduce */
+ fp_montgomery_reduce(&nb->R[0], P, nb->mp);
+ fp_copy(&nb->R[0], Y);
+
+ nb->state = TFM_EXPTMOD_NB_INIT;
+ ret = FP_OKAY;
+ break;
+ } /* switch */
+
+#ifdef WC_RSA_NONBLOCK_TIME
+ /* determine if maximum blocking time has been reached */
+ } while (ret == FP_WOULDBLOCK &&
+ FP_EXPTMOD_NB_CHECKTIME(nb) == TFM_EXPTMOD_NB_CONTINUE);
+#endif
+
+ return ret;
+}
+
+#endif /* WC_RSA_NONBLOCK */
+
+
+/* timing resistant montgomery ladder based exptmod
+ Based on work by Marc Joye, Sung-Ming Yen, "The Montgomery Powering Ladder",
+ Cryptographic Hardware and Embedded Systems, CHES 2002
+*/
+static int _fp_exptmod_ct(fp_int * G, fp_int * X, int digits, fp_int * P,
+ fp_int * Y)
+{
+#ifndef WOLFSSL_SMALL_STACK
+#ifdef WC_NO_CACHE_RESISTANT
+ fp_int R[2];
+#else
+ fp_int R[3]; /* need a temp for cache resistance */
+#endif
+#else
+ fp_int *R;
+#endif
+ fp_digit buf, mp;
+ int err, bitcnt, digidx, y;
+
+ /* now setup montgomery */
+ if ((err = fp_montgomery_setup (P, &mp)) != FP_OKAY) {
+ return err;
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+#ifndef WC_NO_CACHE_RESISTANT
+ R = (fp_int*)XMALLOC(sizeof(fp_int) * 3, NULL, DYNAMIC_TYPE_BIGINT);
+#else
+ R = (fp_int*)XMALLOC(sizeof(fp_int) * 2, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ if (R == NULL)
+ return FP_MEM;
+#endif
+ fp_init(&R[0]);
+ fp_init(&R[1]);
+#ifndef WC_NO_CACHE_RESISTANT
+ fp_init(&R[2]);
+#endif
+
+ /* now we need R mod m */
+ fp_montgomery_calc_normalization (&R[0], P);
+
+ /* now set R[0][1] to G * R mod m */
+ if (fp_cmp_mag(P, G) != FP_GT) {
+ /* G > P so we reduce it first */
+ fp_mod(G, P, &R[1]);
+ } else {
+ fp_copy(G, &R[1]);
+ }
+ fp_mulmod (&R[1], &R[0], P, &R[1]);
+
+ /* for j = t-1 downto 0 do
+ r_!k = R0*R1; r_k = r_k^2
+ */
+
+ /* set initial mode and bit cnt */
+ bitcnt = 1;
+ buf = 0;
+ digidx = digits - 1;
+
+ for (;;) {
+ /* grab next digit as required */
+ if (--bitcnt == 0) {
+ /* if digidx == -1 we are out of digits so break */
+ if (digidx == -1) {
+ break;
+ }
+ /* read next digit and reset bitcnt */
+ buf = X->dp[digidx--];
+ bitcnt = (int)DIGIT_BIT;
+ }
+
+ /* grab the next msb from the exponent */
+ y = (int)(buf >> (DIGIT_BIT - 1)) & 1;
+ buf <<= (fp_digit)1;
+
+ /* do ops */
+ err = fp_mul(&R[0], &R[1], &R[y^1]);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(R, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+ }
+ err = fp_montgomery_reduce(&R[y^1], P, mp);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(R, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+ }
+
+#ifdef WC_NO_CACHE_RESISTANT
+ err = fp_sqr(&R[y], &R[y]);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(R, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+ }
+ err = fp_montgomery_reduce(&R[y], P, mp);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(R, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+ }
+#else
+ /* instead of using R[y] for sqr, which leaks key bit to cache monitor,
+ * use R[2] as temp, make sure address calc is constant, keep
+ * &R[0] and &R[1] in cache */
+ fp_copy((fp_int*) ( ((wolfssl_word)&R[0] & wc_off_on_addr[y^1]) +
+ ((wolfssl_word)&R[1] & wc_off_on_addr[y]) ),
+ &R[2]);
+ err = fp_sqr(&R[2], &R[2]);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(R, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+ }
+ err = fp_montgomery_reduce(&R[2], P, mp);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(R, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+ }
+ fp_copy(&R[2],
+ (fp_int*) ( ((wolfssl_word)&R[0] & wc_off_on_addr[y^1]) +
+ ((wolfssl_word)&R[1] & wc_off_on_addr[y]) ) );
+#endif /* WC_NO_CACHE_RESISTANT */
+ }
+
+ err = fp_montgomery_reduce(&R[0], P, mp);
+ fp_copy(&R[0], Y);
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(R, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return err;
+}
+
+#endif /* TFM_TIMING_RESISTANT */
+
+/* y = g**x (mod b)
+ * Some restrictions... x must be positive and < b
+ */
+static int _fp_exptmod_nct(fp_int * G, fp_int * X, fp_int * P, fp_int * Y)
+{
+ fp_int *res;
+ fp_int *M;
+ fp_digit buf, mp;
+ int err, bitbuf, bitcpy, bitcnt, mode, digidx, x, y, winsize;
+
+ /* find window size */
+ x = fp_count_bits (X);
+ if (x <= 21) {
+ winsize = 1;
+ } else if (x <= 36) {
+ winsize = 3;
+ } else if (x <= 140) {
+ winsize = 4;
+ } else if (x <= 450) {
+ winsize = 5;
+ } else {
+ winsize = 6;
+ }
+
+ /* now setup montgomery */
+ if ((err = fp_montgomery_setup (P, &mp)) != FP_OKAY) {
+ return err;
+ }
+
+ /* only allocate space for what's needed for window plus res */
+ M = (fp_int*)XMALLOC(sizeof(fp_int)*((1 << winsize) + 1), NULL,
+ DYNAMIC_TYPE_BIGINT);
+ if (M == NULL) {
+ return FP_MEM;
+ }
+ res = &M[1 << winsize];
+
+ /* init M array */
+ for(x = 0; x < (1 << winsize); x++)
+ fp_init(&M[x]);
+
+ /* setup result */
+ fp_init(res);
+
+ /* create M table
+ *
+ * The M table contains powers of the input base, e.g. M[x] = G^x mod P
+ *
+ * The first half of the table is not computed though except for M[0] and M[1]
+ */
+
+ /* now we need R mod m */
+ fp_montgomery_calc_normalization (res, P);
+
+ /* now set M[1] to G * R mod m */
+ if (fp_cmp_mag(P, G) != FP_GT) {
+ /* G > P so we reduce it first */
+ fp_mod(G, P, &M[1]);
+ } else {
+ fp_copy(G, &M[1]);
+ }
+ fp_mulmod (&M[1], res, P, &M[1]);
+
+ /* compute the value at M[1<<(winsize-1)] by
+ * squaring M[1] (winsize-1) times */
+ fp_copy (&M[1], &M[1 << (winsize - 1)]);
+ for (x = 0; x < (winsize - 1); x++) {
+ fp_sqr (&M[1 << (winsize - 1)], &M[1 << (winsize - 1)]);
+ err = fp_montgomery_reduce (&M[1 << (winsize - 1)], P, mp);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ }
+
+ /* create upper table */
+ for (x = (1 << (winsize - 1)) + 1; x < (1 << winsize); x++) {
+ err = fp_mul(&M[x - 1], &M[1], &M[x]);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ err = fp_montgomery_reduce(&M[x], P, mp);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ }
+
+ /* set initial mode and bit cnt */
+ mode = 0;
+ bitcnt = (x % DIGIT_BIT) + 1;
+ buf = 0;
+ digidx = X->used - 1;
+ bitcpy = 0;
+ bitbuf = 0;
+
+ for (;;) {
+ /* grab next digit as required */
+ if (--bitcnt == 0) {
+ /* if digidx == -1 we are out of digits so break */
+ if (digidx == -1) {
+ break;
+ }
+ /* read next digit and reset bitcnt */
+ buf = X->dp[digidx--];
+ bitcnt = (int)DIGIT_BIT;
+ }
+
+ /* grab the next msb from the exponent */
+ y = (int)(buf >> (DIGIT_BIT - 1)) & 1;
+ buf <<= (fp_digit)1;
+
+ /* if the bit is zero and mode == 0 then we ignore it
+ * These represent the leading zero bits before the first 1 bit
+ * in the exponent. Technically this opt is not required but it
+ * does lower the # of trivial squaring/reductions used
+ */
+ if (mode == 0 && y == 0) {
+ continue;
+ }
+
+ /* if the bit is zero and mode == 1 then we square */
+ if (mode == 1 && y == 0) {
+ err = fp_sqr(res, res);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ fp_montgomery_reduce(res, P, mp);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ continue;
+ }
+
+ /* else we add it to the window */
+ bitbuf |= (y << (winsize - ++bitcpy));
+ mode = 2;
+
+ if (bitcpy == winsize) {
+ /* ok window is filled so square as required and multiply */
+ /* square first */
+ for (x = 0; x < winsize; x++) {
+ err = fp_sqr(res, res);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ err = fp_montgomery_reduce(res, P, mp);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ }
+
+ /* then multiply */
+ err = fp_mul(res, &M[bitbuf], res);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ err = fp_montgomery_reduce(res, P, mp);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+
+ /* empty window and reset */
+ bitcpy = 0;
+ bitbuf = 0;
+ mode = 1;
+ }
+ }
+
+ /* if bits remain then square/multiply */
+ if (mode == 2 && bitcpy > 0) {
+ /* square then multiply if the bit is set */
+ for (x = 0; x < bitcpy; x++) {
+ err = fp_sqr(res, res);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ err = fp_montgomery_reduce(res, P, mp);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+
+ /* get next bit of the window */
+ bitbuf <<= 1;
+ if ((bitbuf & (1 << winsize)) != 0) {
+ /* then multiply */
+ err = fp_mul(res, &M[1], res);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ err = fp_montgomery_reduce(res, P, mp);
+ if (err != FP_OKAY) {
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+ }
+ }
+ }
+ }
+
+ /* fixup result if Montgomery reduction is used
+ * recall that any value in a Montgomery system is
+ * actually multiplied by R mod n. So we have
+ * to reduce one more time to cancel out the factor
+ * of R.
+ */
+ err = fp_montgomery_reduce(res, P, mp);
+
+ /* swap res with Y */
+ fp_copy (res, Y);
+
+ XFREE(M, NULL, DYNAMIC_TYPE_BIGINT);
+ return err;
+}
+
+
+#ifdef TFM_TIMING_RESISTANT
+#if DIGIT_BIT <= 16
+ #define WINSIZE 2
+#elif DIGIT_BIT <= 32
+ #define WINSIZE 3
+#elif DIGIT_BIT <= 64
+ #define WINSIZE 4
+#elif DIGIT_BIT <= 128
+ #define WINSIZE 5
+#endif
+
+/* y = 2**x (mod b)
+ * Some restrictions... x must be positive and < b
+ */
+static int _fp_exptmod_base_2(fp_int * X, int digits, fp_int * P,
+ fp_int * Y)
+{
+ fp_digit buf, mp;
+ int err, bitbuf, bitcpy, bitcnt, digidx, x, y;
+#ifdef WOLFSSL_SMALL_STACK
+ fp_int *res;
+ fp_int *tmp;
+#else
+ fp_int res[1];
+ fp_int tmp[1];
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ res = (fp_int*)XMALLOC(2*sizeof(fp_int), NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ if (res == NULL) {
+ return FP_MEM;
+ }
+ tmp = &res[1];
+#endif
+
+ /* now setup montgomery */
+ if ((err = fp_montgomery_setup(P, &mp)) != FP_OKAY) {
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#endif
+ return err;
+ }
+
+ /* setup result */
+ fp_init(res);
+ fp_init(tmp);
+
+ fp_mul_2d(P, 1 << WINSIZE, tmp);
+
+ /* now we need R mod m */
+ fp_montgomery_calc_normalization(res, P);
+
+ /* Get the top bits left over after taking WINSIZE bits starting at the
+ * least-significant.
+ */
+ digidx = digits - 1;
+ bitcpy = (digits * DIGIT_BIT) % WINSIZE;
+ if (bitcpy > 0) {
+ bitcnt = (int)DIGIT_BIT - bitcpy;
+ buf = X->dp[digidx--];
+ bitbuf = (int)(buf >> bitcnt);
+ /* Multiply montgomery representation of 1 by 2 ^ top */
+ fp_mul_2d(res, bitbuf, res);
+ fp_add(res, tmp, res);
+ err = fp_mod(res, P, res);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+ /* Move out bits used */
+ buf <<= bitcpy;
+ bitcnt++;
+ }
+ else {
+ bitcnt = 1;
+ buf = 0;
+ }
+
+ /* empty window and reset */
+ bitbuf = 0;
+ bitcpy = 0;
+
+ for (;;) {
+ /* grab next digit as required */
+ if (--bitcnt == 0) {
+ /* if digidx == -1 we are out of digits so break */
+ if (digidx == -1) {
+ break;
+ }
+ /* read next digit and reset bitcnt */
+ buf = X->dp[digidx--];
+ bitcnt = (int)DIGIT_BIT;
+ }
+
+ /* grab the next msb from the exponent */
+ y = (int)(buf >> (DIGIT_BIT - 1)) & 1;
+ buf <<= (fp_digit)1;
+ /* add bit to the window */
+ bitbuf |= (y << (WINSIZE - ++bitcpy));
+
+ if (bitcpy == WINSIZE) {
+ /* ok window is filled so square as required and multiply */
+ /* square first */
+ for (x = 0; x < WINSIZE; x++) {
+ err = fp_sqr(res, res);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+ err = fp_montgomery_reduce(res, P, mp);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+ }
+
+ /* then multiply by 2^bitbuf */
+ fp_mul_2d(res, bitbuf, res);
+ /* Add in value to make mod operation take same time */
+ fp_add(res, tmp, res);
+ err = fp_mod(res, P, res);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+
+ /* empty window and reset */
+ bitcpy = 0;
+ bitbuf = 0;
+ }
+ }
+
+ /* fixup result if Montgomery reduction is used
+ * recall that any value in a Montgomery system is
+ * actually multiplied by R mod n. So we have
+ * to reduce one more time to cancel out the factor
+ * of R.
+ */
+ err = fp_montgomery_reduce(res, P, mp);
+
+ /* swap res with Y */
+ fp_copy(res, Y);
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#endif
+ return err;
+}
+
+#undef WINSIZE
+#else
+#if DIGIT_BIT < 16
+ #define WINSIZE 3
+#elif DIGIT_BIT < 32
+ #define WINSIZE 4
+#elif DIGIT_BIT < 64
+ #define WINSIZE 5
+#elif DIGIT_BIT < 128
+ #define WINSIZE 6
+#elif DIGIT_BIT == 128
+ #define WINSIZE 7
+#endif
+
+/* y = 2**x (mod b)
+ * Some restrictions... x must be positive and < b
+ */
+static int _fp_exptmod_base_2(fp_int * X, int digits, fp_int * P,
+ fp_int * Y)
+{
+ fp_digit buf, mp;
+ int err, bitbuf, bitcpy, bitcnt, digidx, x, y;
+#ifdef WOLFSSL_SMALL_STACK
+ fp_int *res;
+#else
+ fp_int res[1];
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ res = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ if (res == NULL) {
+ return FP_MEM;
+ }
+#endif
+
+ /* now setup montgomery */
+ if ((err = fp_montgomery_setup(P, &mp)) != FP_OKAY) {
+ return err;
+ }
+
+ /* setup result */
+ fp_init(res);
+
+ /* now we need R mod m */
+ fp_montgomery_calc_normalization(res, P);
+
+ /* Get the top bits left over after taking WINSIZE bits starting at the
+ * least-significant.
+ */
+ digidx = digits - 1;
+ bitcpy = (digits * DIGIT_BIT) % WINSIZE;
+ if (bitcpy > 0) {
+ bitcnt = (int)DIGIT_BIT - bitcpy;
+ buf = X->dp[digidx--];
+ bitbuf = (int)(buf >> bitcnt);
+ /* Multiply montgomery representation of 1 by 2 ^ top */
+ fp_mul_2d(res, bitbuf, res);
+ err = fp_mod(res, P, res);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+ /* Move out bits used */
+ buf <<= bitcpy;
+ bitcnt++;
+ }
+ else {
+ bitcnt = 1;
+ buf = 0;
+ }
+
+ /* empty window and reset */
+ bitbuf = 0;
+ bitcpy = 0;
+
+ for (;;) {
+ /* grab next digit as required */
+ if (--bitcnt == 0) {
+ /* if digidx == -1 we are out of digits so break */
+ if (digidx == -1) {
+ break;
+ }
+ /* read next digit and reset bitcnt */
+ buf = X->dp[digidx--];
+ bitcnt = (int)DIGIT_BIT;
+ }
+
+ /* grab the next msb from the exponent */
+ y = (int)(buf >> (DIGIT_BIT - 1)) & 1;
+ buf <<= (fp_digit)1;
+ /* add bit to the window */
+ bitbuf |= (y << (WINSIZE - ++bitcpy));
+
+ if (bitcpy == WINSIZE) {
+ /* ok window is filled so square as required and multiply */
+ /* square first */
+ for (x = 0; x < WINSIZE; x++) {
+ err = fp_sqr(res, res);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+ err = fp_montgomery_reduce(res, P, mp);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+ }
+
+ /* then multiply by 2^bitbuf */
+ fp_mul_2d(res, bitbuf, res);
+ err = fp_mod(res, P, res);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+
+ /* empty window and reset */
+ bitcpy = 0;
+ bitbuf = 0;
+ }
+ }
+
+ /* fixup result if Montgomery reduction is used
+ * recall that any value in a Montgomery system is
+ * actually multiplied by R mod n. So we have
+ * to reduce one more time to cancel out the factor
+ * of R.
+ */
+ err = fp_montgomery_reduce(res, P, mp);
+
+ /* swap res with Y */
+ fp_copy(res, Y);
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(res, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#endif
+ return err;
+}
+
+#undef WINSIZE
+#endif
+
+
+int fp_exptmod(fp_int * G, fp_int * X, fp_int * P, fp_int * Y)
+{
+
+#if defined(WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI) && \
+ !defined(NO_WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI)
+ int x = fp_count_bits (X);
+#endif
+
+ /* handle modulus of zero and prevent overflows */
+ if (fp_iszero(P) || (P->used > (FP_SIZE/2))) {
+ return FP_VAL;
+ }
+ if (fp_isone(P)) {
+ fp_set(Y, 0);
+ return FP_OKAY;
+ }
+ if (fp_iszero(X)) {
+ fp_set(Y, 1);
+ return FP_OKAY;
+ }
+ if (fp_iszero(G)) {
+ fp_set(Y, 0);
+ return FP_OKAY;
+ }
+
+#if defined(WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI) && \
+ !defined(NO_WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI)
+ if(x > EPS_RSA_EXPT_XBTIS) {
+ return esp_mp_exptmod(G, X, x, P, Y);
+ }
+#endif
+
+ if (X->sign == FP_NEG) {
+#ifndef POSITIVE_EXP_ONLY /* reduce stack if assume no negatives */
+ int err;
+ #ifndef WOLFSSL_SMALL_STACK
+ fp_int tmp[2];
+ #else
+ fp_int *tmp;
+ #endif
+
+ #ifdef WOLFSSL_SMALL_STACK
+ tmp = (fp_int*)XMALLOC(sizeof(fp_int) * 2, NULL, DYNAMIC_TYPE_BIGINT);
+ if (tmp == NULL)
+ return FP_MEM;
+ #endif
+
+ /* yes, copy G and invmod it */
+ fp_init_copy(&tmp[0], G);
+ fp_init_copy(&tmp[1], P);
+ tmp[1].sign = FP_ZPOS;
+ err = fp_invmod(&tmp[0], &tmp[1], &tmp[0]);
+ if (err == FP_OKAY) {
+ fp_copy(X, &tmp[1]);
+ tmp[1].sign = FP_ZPOS;
+#ifdef TFM_TIMING_RESISTANT
+ err = _fp_exptmod_ct(&tmp[0], &tmp[1], tmp[1].used, P, Y);
+#else
+ err = _fp_exptmod_nct(&tmp[0], &tmp[1], P, Y);
+#endif
+ if (P->sign == FP_NEG) {
+ fp_add(Y, P, Y);
+ }
+ }
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(tmp, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+#else
+ return FP_VAL;
+#endif
+ }
+ else if (G->used == 1 && G->dp[0] == 2) {
+ return _fp_exptmod_base_2(X, X->used, P, Y);
+ }
+ else {
+ /* Positive exponent so just exptmod */
+#ifdef TFM_TIMING_RESISTANT
+ return _fp_exptmod_ct(G, X, X->used, P, Y);
+#else
+ return _fp_exptmod_nct(G, X, P, Y);
+#endif
+ }
+}
+
+int fp_exptmod_ex(fp_int * G, fp_int * X, int digits, fp_int * P, fp_int * Y)
+{
+
+#if defined(WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI) && \
+ !defined(NO_WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI)
+ int x = fp_count_bits (X);
+#endif
+
+ if (fp_iszero(G)) {
+ fp_set(G, 0);
+ return FP_OKAY;
+ }
+
+ /* prevent overflows */
+ if (P->used > (FP_SIZE/2)) {
+ return FP_VAL;
+ }
+
+#if defined(WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI) && \
+ !defined(NO_WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI)
+ if(x > EPS_RSA_EXPT_XBTIS) {
+ return esp_mp_exptmod(G, X, x, P, Y);
+ }
+#endif
+
+ if (X->sign == FP_NEG) {
+#ifndef POSITIVE_EXP_ONLY /* reduce stack if assume no negatives */
+ int err;
+ #ifndef WOLFSSL_SMALL_STACK
+ fp_int tmp[2];
+ #else
+ fp_int *tmp;
+ #endif
+
+ #ifdef WOLFSSL_SMALL_STACK
+ tmp = (fp_int*)XMALLOC(sizeof(fp_int) * 2, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ if (tmp == NULL)
+ return FP_MEM;
+ #endif
+
+ /* yes, copy G and invmod it */
+ fp_init_copy(&tmp[0], G);
+ fp_init_copy(&tmp[1], P);
+ tmp[1].sign = FP_ZPOS;
+ err = fp_invmod(&tmp[0], &tmp[1], &tmp[0]);
+ if (err == FP_OKAY) {
+ X->sign = FP_ZPOS;
+#ifdef TFM_TIMING_RESISTANT
+ err = _fp_exptmod_ct(&tmp[0], X, digits, P, Y);
+#else
+ err = _fp_exptmod_nct(&tmp[0], X, P, Y);
+ (void)digits;
+#endif
+ if (X != Y) {
+ X->sign = FP_NEG;
+ }
+ if (P->sign == FP_NEG) {
+ fp_add(Y, P, Y);
+ }
+ }
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(tmp, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+#else
+ return FP_VAL;
+#endif
+ }
+ else {
+ /* Positive exponent so just exptmod */
+#ifdef TFM_TIMING_RESISTANT
+ return _fp_exptmod_ct(G, X, digits, P, Y);
+#else
+ return _fp_exptmod_nct(G, X, P, Y);
+#endif
+ }
+}
+
+int fp_exptmod_nct(fp_int * G, fp_int * X, fp_int * P, fp_int * Y)
+{
+#if defined(WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI) && \
+ !defined(NO_WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI)
+ int x = fp_count_bits (X);
+#endif
+
+ if (fp_iszero(G)) {
+ fp_set(G, 0);
+ return FP_OKAY;
+ }
+
+ /* prevent overflows */
+ if (P->used > (FP_SIZE/2)) {
+ return FP_VAL;
+ }
+
+#if defined(WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI) && \
+ !defined(NO_WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI)
+ if(x > EPS_RSA_EXPT_XBTIS) {
+ return esp_mp_exptmod(G, X, x, P, Y);
+ }
+#endif
+
+ if (X->sign == FP_NEG) {
+#ifndef POSITIVE_EXP_ONLY /* reduce stack if assume no negatives */
+ int err;
+ #ifndef WOLFSSL_SMALL_STACK
+ fp_int tmp[2];
+ #else
+ fp_int *tmp;
+ #endif
+
+ #ifdef WOLFSSL_SMALL_STACK
+ tmp = (fp_int*)XMALLOC(sizeof(fp_int) * 2, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ if (tmp == NULL)
+ return FP_MEM;
+ #endif
+
+ /* yes, copy G and invmod it */
+ fp_init_copy(&tmp[0], G);
+ fp_init_copy(&tmp[1], P);
+ tmp[1].sign = FP_ZPOS;
+ err = fp_invmod(&tmp[0], &tmp[1], &tmp[0]);
+ if (err == FP_OKAY) {
+ X->sign = FP_ZPOS;
+ err = _fp_exptmod_nct(&tmp[0], X, P, Y);
+ if (X != Y) {
+ X->sign = FP_NEG;
+ }
+ if (P->sign == FP_NEG) {
+ fp_add(Y, P, Y);
+ }
+ }
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(tmp, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return err;
+#else
+ return FP_VAL;
+#endif
+ }
+ else {
+ /* Positive exponent so just exptmod */
+ return _fp_exptmod_nct(G, X, P, Y);
+ }
+}
+
+/* computes a = 2**b */
+void fp_2expt(fp_int *a, int b)
+{
+ int z;
+
+ /* zero a as per default */
+ fp_zero (a);
+
+ if (b < 0) {
+ return;
+ }
+
+ z = b / DIGIT_BIT;
+ if (z >= FP_SIZE) {
+ return;
+ }
+
+ /* set the used count of where the bit will go */
+ a->used = z + 1;
+
+ /* put the single bit in its place */
+ a->dp[z] = ((fp_digit)1) << (b % DIGIT_BIT);
+}
+
+/* b = a*a */
+int fp_sqr(fp_int *A, fp_int *B)
+{
+ int err;
+ int y, oldused;
+
+ oldused = B->used;
+ y = A->used;
+
+ /* call generic if we're out of range */
+ if (y + y > FP_SIZE) {
+ err = fp_sqr_comba(A, B);
+ goto clean;
+ }
+
+#if defined(TFM_SQR3) && FP_SIZE >= 6
+ if (y <= 3) {
+ err = fp_sqr_comba3(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR4) && FP_SIZE >= 8
+ if (y == 4) {
+ err = fp_sqr_comba4(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR6) && FP_SIZE >= 12
+ if (y <= 6) {
+ err = fp_sqr_comba6(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR7) && FP_SIZE >= 14
+ if (y == 7) {
+ err = fp_sqr_comba7(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR8) && FP_SIZE >= 16
+ if (y == 8) {
+ err = fp_sqr_comba8(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR9) && FP_SIZE >= 18
+ if (y == 9) {
+ err = fp_sqr_comba9(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR12) && FP_SIZE >= 24
+ if (y <= 12) {
+ err = fp_sqr_comba12(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR17) && FP_SIZE >= 34
+ if (y <= 17) {
+ err = fp_sqr_comba17(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SMALL_SET)
+ if (y <= 16) {
+ err = fp_sqr_comba_small(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR20) && FP_SIZE >= 40
+ if (y <= 20) {
+ err = fp_sqr_comba20(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR24) && FP_SIZE >= 48
+ if (y <= 24) {
+ err = fp_sqr_comba24(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR28) && FP_SIZE >= 56
+ if (y <= 28) {
+ err = fp_sqr_comba28(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR32) && FP_SIZE >= 64
+ if (y <= 32) {
+ err = fp_sqr_comba32(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR48) && FP_SIZE >= 96
+ if (y <= 48) {
+ err = fp_sqr_comba48(A,B);
+ goto clean;
+ }
+#endif
+#if defined(TFM_SQR64) && FP_SIZE >= 128
+ if (y <= 64) {
+ err = fp_sqr_comba64(A,B);
+ goto clean;
+ }
+#endif
+ err = fp_sqr_comba(A, B);
+
+clean:
+ /* zero any excess digits on the destination that we didn't write to */
+ for (y = B->used; y >= 0 && y < oldused; y++) {
+ B->dp[y] = 0;
+ }
+
+ return err;
+}
+
+/* generic comba squarer */
+int fp_sqr_comba(fp_int *A, fp_int *B)
+{
+ int pa, ix, iz;
+ fp_digit c0, c1, c2;
+#ifdef TFM_ISO
+ fp_word tt;
+#endif
+ fp_int *dst;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int tmp[1];
+#else
+ fp_int *tmp;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ tmp = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (tmp == NULL)
+ return FP_MEM;
+#endif
+
+ /* get size of output and trim */
+ pa = A->used + A->used;
+ if (pa >= FP_SIZE) {
+ pa = FP_SIZE-1;
+ }
+
+ /* number of output digits to produce */
+ COMBA_START;
+ COMBA_CLEAR;
+
+ if (A == B) {
+ fp_init(tmp);
+ dst = tmp;
+ } else {
+ fp_zero(B);
+ dst = B;
+ }
+
+ for (ix = 0; ix < pa; ix++) {
+ int tx, ty, iy;
+ fp_digit *tmpy, *tmpx;
+
+ /* get offsets into the two bignums */
+ ty = MIN(A->used-1, ix);
+ tx = ix - ty;
+
+ /* setup temp aliases */
+ tmpx = A->dp + tx;
+ tmpy = A->dp + ty;
+
+ /* this is the number of times the loop will iterate,
+ while (tx++ < a->used && ty-- >= 0) { ... }
+ */
+ iy = MIN(A->used-tx, ty+1);
+
+ /* now for squaring tx can never equal ty
+ * we halve the distance since they approach
+ * at a rate of 2x and we have to round because
+ * odd cases need to be executed
+ */
+ iy = MIN(iy, (ty-tx+1)>>1);
+
+ /* forward carries */
+ COMBA_FORWARD;
+
+ /* execute loop */
+ for (iz = 0; iz < iy; iz++) {
+ SQRADD2(*tmpx++, *tmpy--);
+ }
+
+ /* even columns have the square term in them */
+ if ((ix&1) == 0) {
+ /* TAO change COMBA_ADD back to SQRADD */
+ SQRADD(A->dp[ix>>1], A->dp[ix>>1]);
+ }
+
+ /* store it */
+ COMBA_STORE(dst->dp[ix]);
+ }
+
+ COMBA_FINI;
+
+ /* setup dest */
+ dst->used = pa;
+ fp_clamp (dst);
+ if (dst != B) {
+ fp_copy(dst, B);
+ }
+
+ /* Variables used but not seen by cppcheck. */
+ (void)c0; (void)c1; (void)c2;
+#ifdef TFM_ISO
+ (void)tt;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(tmp, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+int fp_cmp(fp_int *a, fp_int *b)
+{
+ if (a->sign == FP_NEG && b->sign == FP_ZPOS) {
+ return FP_LT;
+ } else if (a->sign == FP_ZPOS && b->sign == FP_NEG) {
+ return FP_GT;
+ } else {
+ /* compare digits */
+ if (a->sign == FP_NEG) {
+ /* if negative compare opposite direction */
+ return fp_cmp_mag(b, a);
+ } else {
+ return fp_cmp_mag(a, b);
+ }
+ }
+}
+
+/* compare against a single digit */
+int fp_cmp_d(fp_int *a, fp_digit b)
+{
+ /* special case for zero*/
+ if (a->used == 0 && b == 0)
+ return FP_EQ;
+
+ /* compare based on sign */
+ if ((b && a->used == 0) || a->sign == FP_NEG) {
+ return FP_LT;
+ }
+
+ /* compare based on magnitude */
+ if (a->used > 1) {
+ return FP_GT;
+ }
+
+ /* compare the only digit of a to b */
+ if (a->dp[0] > b) {
+ return FP_GT;
+ } else if (a->dp[0] < b) {
+ return FP_LT;
+ } else {
+ return FP_EQ;
+ }
+
+}
+
+int fp_cmp_mag(fp_int *a, fp_int *b)
+{
+ int x;
+
+ if (a->used > b->used) {
+ return FP_GT;
+ } else if (a->used < b->used) {
+ return FP_LT;
+ } else {
+ for (x = a->used - 1; x >= 0; x--) {
+ if (a->dp[x] > b->dp[x]) {
+ return FP_GT;
+ } else if (a->dp[x] < b->dp[x]) {
+ return FP_LT;
+ }
+ }
+ }
+ return FP_EQ;
+}
+
+/* sets up the montgomery reduction */
+int fp_montgomery_setup(fp_int *a, fp_digit *rho)
+{
+ fp_digit x, b;
+
+/* fast inversion mod 2**k
+ *
+ * Based on the fact that
+ *
+ * XA = 1 (mod 2**n) => (X(2-XA)) A = 1 (mod 2**2n)
+ * => 2*X*A - X*X*A*A = 1
+ * => 2*(1) - (1) = 1
+ */
+ b = a->dp[0];
+
+ if ((b & 1) == 0) {
+ return FP_VAL;
+ }
+
+ x = (((b + 2) & 4) << 1) + b; /* here x*a==1 mod 2**4 */
+ x *= 2 - b * x; /* here x*a==1 mod 2**8 */
+ x *= 2 - b * x; /* here x*a==1 mod 2**16 */
+ x *= 2 - b * x; /* here x*a==1 mod 2**32 */
+#ifdef FP_64BIT
+ x *= 2 - b * x; /* here x*a==1 mod 2**64 */
+#endif
+
+ /* rho = -1/m mod b */
+ *rho = (fp_digit) (((fp_word) 1 << ((fp_word) DIGIT_BIT)) - ((fp_word)x));
+
+ return FP_OKAY;
+}
+
+/* computes a = B**n mod b without division or multiplication useful for
+ * normalizing numbers in a Montgomery system.
+ */
+void fp_montgomery_calc_normalization(fp_int *a, fp_int *b)
+{
+ int x, bits;
+
+ /* how many bits of last digit does b use */
+ bits = fp_count_bits (b) % DIGIT_BIT;
+ if (!bits) bits = DIGIT_BIT;
+
+ /* compute A = B^(n-1) * 2^(bits-1) */
+ if (b->used > 1) {
+ fp_2expt (a, (b->used - 1) * DIGIT_BIT + bits - 1);
+ } else {
+ fp_set(a, 1);
+ bits = 1;
+ }
+
+ /* now compute C = A * B mod b */
+ for (x = bits - 1; x < (int)DIGIT_BIT; x++) {
+ fp_mul_2 (a, a);
+ if (fp_cmp_mag (a, b) != FP_LT) {
+ s_fp_sub (a, b, a);
+ }
+ }
+}
+
+
+#ifdef TFM_SMALL_MONT_SET
+ #include "fp_mont_small.i"
+#endif
+
+#ifdef HAVE_INTEL_MULX
+static WC_INLINE void innermul8_mulx(fp_digit *c_mulx, fp_digit *cy_mulx, fp_digit *tmpm, fp_digit mu)
+{
+ fp_digit cy = *cy_mulx ;
+ INNERMUL8_MULX ;
+ *cy_mulx = cy ;
+}
+
+/* computes x/R == x (mod N) via Montgomery Reduction */
+static int fp_montgomery_reduce_mulx(fp_int *a, fp_int *m, fp_digit mp)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_digit c[FP_SIZE+1];
+#else
+ fp_digit *c;
+#endif
+ fp_digit *_c, *tmpm, mu = 0;
+ int oldused, x, y, pa;
+
+ /* bail if too large */
+ if (m->used > (FP_SIZE/2)) {
+ (void)mu; /* shut up compiler */
+ return FP_OKAY;
+ }
+
+#ifdef TFM_SMALL_MONT_SET
+ if (m->used <= 16) {
+ return fp_montgomery_reduce_small(a, m, mp);
+ }
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ /* only allocate space for what's needed for window plus res */
+ c = (fp_digit*)XMALLOC(sizeof(fp_digit)*(FP_SIZE + 1), NULL, DYNAMIC_TYPE_BIGINT);
+ if (c == NULL) {
+ return FP_MEM;
+ }
+#endif
+
+ /* now zero the buff */
+ XMEMSET(c, 0, sizeof(fp_digit)*(FP_SIZE + 1));
+ pa = m->used;
+
+ /* copy the input */
+ oldused = a->used;
+ for (x = 0; x < oldused; x++) {
+ c[x] = a->dp[x];
+ }
+ MONT_START;
+
+ for (x = 0; x < pa; x++) {
+ fp_digit cy = 0;
+ /* get Mu for this round */
+ LOOP_START;
+ _c = c + x;
+ tmpm = m->dp;
+ y = 0;
+ for (; y < (pa & ~7); y += 8) {
+ innermul8_mulx(_c, &cy, tmpm, mu) ;
+ _c += 8;
+ tmpm += 8;
+ }
+ for (; y < pa; y++) {
+ INNERMUL;
+ ++_c;
+ }
+ LOOP_END;
+ while (cy) {
+ PROPCARRY;
+ ++_c;
+ }
+ }
+
+ /* now copy out */
+ _c = c + pa;
+ tmpm = a->dp;
+ for (x = 0; x < pa+1; x++) {
+ *tmpm++ = *_c++;
+ }
+
+ /* zero any excess digits on the destination that we didn't write to */
+ for (; x < oldused; x++) {
+ *tmpm++ = 0;
+ }
+
+ MONT_FINI;
+
+ a->used = pa+1;
+ fp_clamp(a);
+
+ /* if A >= m then A = A - m */
+ if (fp_cmp_mag (a, m) != FP_LT) {
+ s_fp_sub (a, m, a);
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(c, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+#endif
+
+/* computes x/R == x (mod N) via Montgomery Reduction */
+int fp_montgomery_reduce(fp_int *a, fp_int *m, fp_digit mp)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_digit c[FP_SIZE+1];
+#else
+ fp_digit *c;
+#endif
+ fp_digit *_c, *tmpm, mu = 0;
+ int oldused, x, y, pa, err = 0;
+
+ IF_HAVE_INTEL_MULX(err = fp_montgomery_reduce_mulx(a, m, mp), return err) ;
+ (void)err;
+
+ /* bail if too large */
+ if (m->used > (FP_SIZE/2)) {
+ (void)mu; /* shut up compiler */
+ return FP_OKAY;
+ }
+
+#ifdef TFM_SMALL_MONT_SET
+ if (m->used <= 16) {
+ return fp_montgomery_reduce_small(a, m, mp);
+ }
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ /* only allocate space for what's needed for window plus res */
+ c = (fp_digit*)XMALLOC(sizeof(fp_digit)*(FP_SIZE + 1), NULL, DYNAMIC_TYPE_BIGINT);
+ if (c == NULL) {
+ return FP_MEM;
+ }
+#endif
+
+ /* now zero the buff */
+ XMEMSET(c, 0, sizeof(fp_digit)*(FP_SIZE + 1));
+ pa = m->used;
+
+ /* copy the input */
+ oldused = a->used;
+ for (x = 0; x < oldused; x++) {
+ c[x] = a->dp[x];
+ }
+ MONT_START;
+
+ for (x = 0; x < pa; x++) {
+ fp_digit cy = 0;
+ /* get Mu for this round */
+ LOOP_START;
+ _c = c + x;
+ tmpm = m->dp;
+ y = 0;
+#if defined(INNERMUL8)
+ for (; y < (pa & ~7); y += 8) {
+ INNERMUL8 ;
+ _c += 8;
+ tmpm += 8;
+ }
+#endif
+ for (; y < pa; y++) {
+ INNERMUL;
+ ++_c;
+ }
+ LOOP_END;
+ while (cy) {
+ PROPCARRY;
+ ++_c;
+ }
+ }
+
+ /* now copy out */
+ _c = c + pa;
+ tmpm = a->dp;
+ for (x = 0; x < pa+1; x++) {
+ *tmpm++ = *_c++;
+ }
+
+ /* zero any excess digits on the destination that we didn't write to */
+ for (; x < oldused; x++) {
+ *tmpm++ = 0;
+ }
+
+ MONT_FINI;
+
+ a->used = pa+1;
+ fp_clamp(a);
+
+ /* if A >= m then A = A - m */
+ if (fp_cmp_mag (a, m) != FP_LT) {
+ s_fp_sub (a, m, a);
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(c, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+void fp_read_unsigned_bin(fp_int *a, const unsigned char *b, int c)
+{
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ const word32 maxC = (a->size * sizeof(fp_digit));
+#else
+ const word32 maxC = (FP_SIZE * sizeof(fp_digit));
+#endif
+
+ /* zero the int */
+ fp_zero (a);
+
+ /* if input b excess max, then truncate */
+ if (c > 0 && (word32)c > maxC) {
+ int excess = (c - maxC);
+ c -= excess;
+ b += excess;
+ }
+
+ /* If we know the endianness of this architecture, and we're using
+ 32-bit fp_digits, we can optimize this */
+#if (defined(LITTLE_ENDIAN_ORDER) || defined(BIG_ENDIAN_ORDER)) && \
+ defined(FP_32BIT)
+ /* But not for both simultaneously */
+#if defined(LITTLE_ENDIAN_ORDER) && defined(BIG_ENDIAN_ORDER)
+#error Both LITTLE_ENDIAN_ORDER and BIG_ENDIAN_ORDER defined.
+#endif
+ {
+ unsigned char *pd = (unsigned char *)a->dp;
+
+ a->used = (c + sizeof(fp_digit) - 1)/sizeof(fp_digit);
+ /* read the bytes in */
+#ifdef BIG_ENDIAN_ORDER
+ {
+ /* Use Duff's device to unroll the loop. */
+ int idx = (c - 1) & ~3;
+ switch (c % 4) {
+ case 0: do { pd[idx+0] = *b++; // fallthrough
+ case 3: pd[idx+1] = *b++; // fallthrough
+ case 2: pd[idx+2] = *b++; // fallthrough
+ case 1: pd[idx+3] = *b++; // fallthrough
+ idx -= 4;
+ } while ((c -= 4) > 0);
+ }
+ }
+#else
+ for (c -= 1; c >= 0; c -= 1) {
+ pd[c] = *b++;
+ }
+#endif
+ }
+#else
+ /* read the bytes in */
+ for (; c > 0; c--) {
+ fp_mul_2d (a, 8, a);
+ a->dp[0] |= *b++;
+
+ if (a->used == 0) {
+ a->used = 1;
+ }
+ }
+#endif
+ fp_clamp (a);
+}
+
+int fp_to_unsigned_bin_at_pos(int x, fp_int *t, unsigned char *b)
+{
+#if DIGIT_BIT == 64 || DIGIT_BIT == 32
+ int i, j;
+ fp_digit n;
+
+ for (j=0,i=0; i<t->used-1; ) {
+ b[x++] = (unsigned char)(t->dp[i] >> j);
+ j += 8;
+ i += j == DIGIT_BIT;
+ j &= DIGIT_BIT - 1;
+ }
+ n = t->dp[i];
+ while (n != 0) {
+ b[x++] = (unsigned char)n;
+ n >>= 8;
+ }
+ return x;
+#else
+ while (fp_iszero (t) == FP_NO) {
+ b[x++] = (unsigned char) (t->dp[0] & 255);
+ fp_div_2d (t, 8, t, NULL);
+ }
+ return x;
+#endif
+}
+
+int fp_to_unsigned_bin(fp_int *a, unsigned char *b)
+{
+ int x;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init_copy(t, a);
+
+ x = fp_to_unsigned_bin_at_pos(0, t, b);
+ fp_reverse (b, x);
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+int fp_to_unsigned_bin_len(fp_int *a, unsigned char *b, int c)
+{
+#if DIGIT_BIT == 64 || DIGIT_BIT == 32
+ int i, j, x;
+
+ for (x=c-1,j=0,i=0; x >= 0; x--) {
+ b[x] = (unsigned char)(a->dp[i] >> j);
+ j += 8;
+ i += j == DIGIT_BIT;
+ j &= DIGIT_BIT - 1;
+ }
+
+ return FP_OKAY;
+#else
+ int x;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init_copy(t, a);
+
+ for (x = 0; x < c; x++) {
+ b[x] = (unsigned char) (t->dp[0] & 255);
+ fp_div_2d (t, 8, t, NULL);
+ }
+ fp_reverse (b, x);
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+#endif
+}
+
+int fp_unsigned_bin_size(fp_int *a)
+{
+ int size = fp_count_bits (a);
+ return (size / 8 + ((size & 7) != 0 ? 1 : 0));
+}
+
+void fp_set(fp_int *a, fp_digit b)
+{
+ fp_zero(a);
+ a->dp[0] = b;
+ a->used = a->dp[0] ? 1 : 0;
+}
+
+
+#ifndef MP_SET_CHUNK_BITS
+ #define MP_SET_CHUNK_BITS 4
+#endif
+void fp_set_int(fp_int *a, unsigned long b)
+{
+ int x;
+
+ /* use direct fp_set if b is less than fp_digit max */
+ if (b < FP_DIGIT_MAX) {
+ fp_set (a, (fp_digit)b);
+ return;
+ }
+
+ fp_zero (a);
+
+ /* set chunk bits at a time */
+ for (x = 0; x < (int)(sizeof(b) * 8) / MP_SET_CHUNK_BITS; x++) {
+ fp_mul_2d (a, MP_SET_CHUNK_BITS, a);
+
+ /* OR in the top bits of the source */
+ a->dp[0] |= (b >> ((sizeof(b) * 8) - MP_SET_CHUNK_BITS)) &
+ ((1 << MP_SET_CHUNK_BITS) - 1);
+
+ /* shift the source up to the next chunk bits */
+ b <<= MP_SET_CHUNK_BITS;
+
+ /* ensure that digits are not clamped off */
+ a->used += 1;
+ }
+
+ /* clamp digits */
+ fp_clamp(a);
+}
+
+/* check if a bit is set */
+int fp_is_bit_set (fp_int *a, fp_digit b)
+{
+ fp_digit i;
+
+ if (b > FP_MAX_BITS)
+ return 0;
+ else
+ i = b/DIGIT_BIT;
+
+ if ((fp_digit)a->used < i)
+ return 0;
+
+ return (int)((a->dp[i] >> b%DIGIT_BIT) & (fp_digit)1);
+}
+
+/* set the b bit of a */
+int fp_set_bit (fp_int * a, fp_digit b)
+{
+ fp_digit i;
+
+ if (b > FP_MAX_BITS)
+ return 0;
+ else
+ i = b/DIGIT_BIT;
+
+ /* set the used count of where the bit will go if required */
+ if (a->used < (int)(i+1))
+ a->used = (int)(i+1);
+
+ /* put the single bit in its place */
+ a->dp[i] |= ((fp_digit)1) << (b % DIGIT_BIT);
+
+ return MP_OKAY;
+}
+
+int fp_count_bits (fp_int * a)
+{
+ int r;
+ fp_digit q;
+
+ /* shortcut */
+ if (a->used == 0) {
+ return 0;
+ }
+
+ /* get number of digits and add that */
+ r = (a->used - 1) * DIGIT_BIT;
+
+ /* take the last digit and count the bits in it */
+ q = a->dp[a->used - 1];
+ while (q > ((fp_digit) 0)) {
+ ++r;
+ q >>= ((fp_digit) 1);
+ }
+
+ return r;
+}
+
+int fp_leading_bit(fp_int *a)
+{
+ int bit = 0;
+
+ if (a->used != 0) {
+ fp_digit q = a->dp[a->used - 1];
+ int qSz = sizeof(fp_digit);
+
+ while (qSz > 0) {
+ if ((unsigned char)q != 0)
+ bit = (q & 0x80) != 0;
+ q >>= 8;
+ qSz--;
+ }
+ }
+
+ return bit;
+}
+
+void fp_lshd(fp_int *a, int x)
+{
+ int y;
+
+ /* move up and truncate as required */
+ y = MIN(a->used + x - 1, (int)(FP_SIZE-1));
+
+ /* store new size */
+ a->used = y + 1;
+
+ /* move digits */
+ for (; y >= x; y--) {
+ a->dp[y] = a->dp[y-x];
+ }
+
+ /* zero lower digits */
+ for (; y >= 0; y--) {
+ a->dp[y] = 0;
+ }
+
+ /* clamp digits */
+ fp_clamp(a);
+}
+
+
+/* right shift by bit count */
+void fp_rshb(fp_int *c, int x)
+{
+ fp_digit *tmpc, mask, shift;
+ fp_digit r, rr;
+ fp_digit D = x;
+
+ if (fp_iszero(c)) return;
+
+ /* mask */
+ mask = (((fp_digit)1) << D) - 1;
+
+ /* shift for lsb */
+ shift = DIGIT_BIT - D;
+
+ /* alias */
+ tmpc = c->dp + (c->used - 1);
+
+ /* carry */
+ r = 0;
+ for (x = c->used - 1; x >= 0; x--) {
+ /* get the lower bits of this word in a temp */
+ rr = *tmpc & mask;
+
+ /* shift the current word and mix in the carry bits from previous word */
+ *tmpc = (*tmpc >> D) | (r << shift);
+ --tmpc;
+
+ /* set the carry to the carry bits of the current word found above */
+ r = rr;
+ }
+
+ /* clamp digits */
+ fp_clamp(c);
+}
+
+
+void fp_rshd(fp_int *a, int x)
+{
+ int y;
+
+ /* too many digits just zero and return */
+ if (x >= a->used) {
+ fp_zero(a);
+ return;
+ }
+
+ /* shift */
+ for (y = 0; y < a->used - x; y++) {
+ a->dp[y] = a->dp[y+x];
+ }
+
+ /* zero rest */
+ for (; y < a->used; y++) {
+ a->dp[y] = 0;
+ }
+
+ /* decrement count */
+ a->used -= x;
+ fp_clamp(a);
+}
+
+/* reverse an array, used for radix code */
+void fp_reverse (unsigned char *s, int len)
+{
+ int ix, iy;
+ unsigned char t;
+
+ ix = 0;
+ iy = len - 1;
+ while (ix < iy) {
+ t = s[ix];
+ s[ix] = s[iy];
+ s[iy] = t;
+ ++ix;
+ --iy;
+ }
+}
+
+
+/* c = a - b */
+int fp_sub_d(fp_int *a, fp_digit b, fp_int *c)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int tmp[1];
+#else
+ fp_int *tmp;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ tmp = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (tmp == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init(tmp);
+ fp_set(tmp, b);
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ if (c->size < FP_SIZE) {
+ fp_sub(a, tmp, tmp);
+ fp_copy(tmp, c);
+ } else
+#endif
+ {
+ fp_sub(a, tmp, c);
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(tmp, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+
+/* wolfSSL callers from normal lib */
+
+/* init a new mp_int */
+int mp_init (mp_int * a)
+{
+ if (a)
+ fp_init(a);
+ return MP_OKAY;
+}
+
+void fp_init(fp_int *a)
+{
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ a->size = FP_SIZE;
+#endif
+#ifdef HAVE_WOLF_BIGINT
+ wc_bigint_init(&a->raw);
+#endif
+ fp_zero(a);
+}
+
+void fp_zero(fp_int *a)
+{
+ int size;
+ a->used = 0;
+ a->sign = FP_ZPOS;
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ size = a->size;
+#else
+ size = FP_SIZE;
+#endif
+ XMEMSET(a->dp, 0, size * sizeof(fp_digit));
+}
+
+void fp_clear(fp_int *a)
+{
+ int size;
+ a->used = 0;
+ a->sign = FP_ZPOS;
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ size = a->size;
+#else
+ size = FP_SIZE;
+#endif
+ XMEMSET(a->dp, 0, size * sizeof(fp_digit));
+ fp_free(a);
+}
+
+void fp_forcezero (mp_int * a)
+{
+ int size;
+ a->used = 0;
+ a->sign = FP_ZPOS;
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ size = a->size;
+#else
+ size = FP_SIZE;
+#endif
+ ForceZero(a->dp, size * sizeof(fp_digit));
+#ifdef HAVE_WOLF_BIGINT
+ wc_bigint_zero(&a->raw);
+#endif
+ fp_free(a);
+}
+
+void mp_forcezero (mp_int * a)
+{
+ fp_forcezero(a);
+}
+
+void fp_free(fp_int* a)
+{
+#ifdef HAVE_WOLF_BIGINT
+ wc_bigint_free(&a->raw);
+#else
+ (void)a;
+#endif
+}
+
+
+/* clear one (frees) */
+void mp_clear (mp_int * a)
+{
+ if (a == NULL)
+ return;
+ fp_clear(a);
+}
+
+void mp_free(mp_int* a)
+{
+ fp_free(a);
+}
+
+/* handle up to 6 inits */
+int mp_init_multi(mp_int* a, mp_int* b, mp_int* c, mp_int* d,
+ mp_int* e, mp_int* f)
+{
+ if (a)
+ fp_init(a);
+ if (b)
+ fp_init(b);
+ if (c)
+ fp_init(c);
+ if (d)
+ fp_init(d);
+ if (e)
+ fp_init(e);
+ if (f)
+ fp_init(f);
+
+ return MP_OKAY;
+}
+
+/* high level addition (handles signs) */
+int mp_add (mp_int * a, mp_int * b, mp_int * c)
+{
+ fp_add(a, b, c);
+ return MP_OKAY;
+}
+
+/* high level subtraction (handles signs) */
+int mp_sub (mp_int * a, mp_int * b, mp_int * c)
+{
+ fp_sub(a, b, c);
+ return MP_OKAY;
+}
+
+/* high level multiplication (handles sign) */
+#if defined(FREESCALE_LTC_TFM)
+int wolfcrypt_mp_mul(mp_int * a, mp_int * b, mp_int * c)
+#else
+int mp_mul (mp_int * a, mp_int * b, mp_int * c)
+#endif
+{
+ return fp_mul(a, b, c);
+}
+
+int mp_mul_d (mp_int * a, mp_digit b, mp_int * c)
+{
+ fp_mul_d(a, b, c);
+ return MP_OKAY;
+}
+
+/* d = a * b (mod c) */
+#if defined(FREESCALE_LTC_TFM)
+int wolfcrypt_mp_mulmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
+#else
+int mp_mulmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d)
+#endif
+{
+ #if defined(WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI) && \
+ !defined(NO_WOLFSSL_ESP32WROOM32_CRYPT_RSA_PRI)
+ int A = fp_count_bits (a);
+ int B = fp_count_bits (b);
+
+ if( A >= ESP_RSA_MULM_BITS && B >= ESP_RSA_MULM_BITS)
+ return esp_mp_mulmod(a, b, c, d);
+ else
+ #endif
+ return fp_mulmod(a, b, c, d);
+}
+
+/* d = a - b (mod c) */
+int mp_submod(mp_int *a, mp_int *b, mp_int *c, mp_int *d)
+{
+ return fp_submod(a, b, c, d);
+}
+
+/* d = a + b (mod c) */
+int mp_addmod(mp_int *a, mp_int *b, mp_int *c, mp_int *d)
+{
+ return fp_addmod(a, b, c, d);
+}
+
+/* c = a mod b, 0 <= c < b */
+#if defined(FREESCALE_LTC_TFM)
+int wolfcrypt_mp_mod (mp_int * a, mp_int * b, mp_int * c)
+#else
+int mp_mod (mp_int * a, mp_int * b, mp_int * c)
+#endif
+{
+ return fp_mod (a, b, c);
+}
+
+/* hac 14.61, pp608 */
+#if defined(FREESCALE_LTC_TFM)
+int wolfcrypt_mp_invmod (mp_int * a, mp_int * b, mp_int * c)
+#else
+int mp_invmod (mp_int * a, mp_int * b, mp_int * c)
+#endif
+{
+ return fp_invmod(a, b, c);
+}
+
+/* hac 14.61, pp608 */
+int mp_invmod_mont_ct (mp_int * a, mp_int * b, mp_int * c, mp_digit mp)
+{
+ return fp_invmod_mont_ct(a, b, c, mp);
+}
+
+/* this is a shell function that calls either the normal or Montgomery
+ * exptmod functions. Originally the call to the montgomery code was
+ * embedded in the normal function but that wasted a lot of stack space
+ * for nothing (since 99% of the time the Montgomery code would be called)
+ */
+#if defined(FREESCALE_LTC_TFM)
+int wolfcrypt_mp_exptmod (mp_int * G, mp_int * X, mp_int * P, mp_int * Y)
+#else
+int mp_exptmod (mp_int * G, mp_int * X, mp_int * P, mp_int * Y)
+#endif
+{
+ return fp_exptmod(G, X, P, Y);
+}
+
+int mp_exptmod_ex (mp_int * G, mp_int * X, int digits, mp_int * P, mp_int * Y)
+{
+ return fp_exptmod_ex(G, X, digits, P, Y);
+}
+
+int mp_exptmod_nct (mp_int * G, mp_int * X, mp_int * P, mp_int * Y)
+{
+ return fp_exptmod_nct(G, X, P, Y);
+}
+
+
+/* compare two ints (signed)*/
+int mp_cmp (mp_int * a, mp_int * b)
+{
+ return fp_cmp(a, b);
+}
+
+/* compare a digit */
+int mp_cmp_d(mp_int * a, mp_digit b)
+{
+ return fp_cmp_d(a, b);
+}
+
+/* get the size for an unsigned equivalent */
+int mp_unsigned_bin_size (mp_int * a)
+{
+ return fp_unsigned_bin_size(a);
+}
+
+int mp_to_unsigned_bin_at_pos(int x, fp_int *t, unsigned char *b)
+{
+ return fp_to_unsigned_bin_at_pos(x, t, b);
+}
+
+/* store in unsigned [big endian] format */
+int mp_to_unsigned_bin (mp_int * a, unsigned char *b)
+{
+ return fp_to_unsigned_bin(a,b);
+}
+
+int mp_to_unsigned_bin_len(mp_int * a, unsigned char *b, int c)
+{
+ return fp_to_unsigned_bin_len(a, b, c);
+}
+/* reads a unsigned char array, assumes the msb is stored first [big endian] */
+int mp_read_unsigned_bin (mp_int * a, const unsigned char *b, int c)
+{
+ fp_read_unsigned_bin(a, b, c);
+ return MP_OKAY;
+}
+
+
+int mp_sub_d(fp_int *a, fp_digit b, fp_int *c)
+{
+ return fp_sub_d(a, b, c);
+}
+
+int mp_mul_2d(fp_int *a, int b, fp_int *c)
+{
+ fp_mul_2d(a, b, c);
+ return MP_OKAY;
+}
+
+int mp_2expt(fp_int* a, int b)
+{
+ fp_2expt(a, b);
+ return MP_OKAY;
+}
+
+int mp_div(fp_int * a, fp_int * b, fp_int * c, fp_int * d)
+{
+ return fp_div(a, b, c, d);
+}
+
+int mp_div_2d(fp_int* a, int b, fp_int* c, fp_int* d)
+{
+ fp_div_2d(a, b, c, d);
+ return MP_OKAY;
+}
+
+void fp_copy(fp_int *a, fp_int *b)
+{
+ /* if source and destination are different */
+ if (a != b) {
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ /* verify a will fit in b */
+ if (b->size >= a->used) {
+ int x, oldused;
+ oldused = b->used;
+ b->used = a->used;
+ b->sign = a->sign;
+
+ XMEMCPY(b->dp, a->dp, a->used * sizeof(fp_digit));
+
+ /* zero any excess digits on the destination that we didn't write to */
+ for (x = b->used; x >= 0 && x < oldused; x++) {
+ b->dp[x] = 0;
+ }
+ }
+ else {
+ /* TODO: Handle error case */
+ }
+#else
+ /* all dp's are same size, so do straight copy */
+ b->used = a->used;
+ b->sign = a->sign;
+ XMEMCPY(b->dp, a->dp, FP_SIZE * sizeof(fp_digit));
+#endif
+ }
+}
+
+void fp_init_copy(fp_int *a, fp_int* b)
+{
+ if (a != b) {
+ fp_init(a);
+ fp_copy(b, a);
+ }
+}
+
+/* fast math wrappers */
+int mp_copy(fp_int* a, fp_int* b)
+{
+ fp_copy(a, b);
+ return MP_OKAY;
+}
+
+int mp_isodd(mp_int* a)
+{
+ return fp_isodd(a);
+}
+
+int mp_iszero(mp_int* a)
+{
+ return fp_iszero(a);
+}
+
+int mp_count_bits (mp_int* a)
+{
+ return fp_count_bits(a);
+}
+
+int mp_leading_bit (mp_int* a)
+{
+ return fp_leading_bit(a);
+}
+
+void mp_rshb (mp_int* a, int x)
+{
+ fp_rshb(a, x);
+}
+
+void mp_rshd (mp_int* a, int x)
+{
+ fp_rshd(a, x);
+}
+
+int mp_set_int(mp_int *a, unsigned long b)
+{
+ fp_set_int(a, b);
+ return MP_OKAY;
+}
+
+int mp_is_bit_set (mp_int *a, mp_digit b)
+{
+ return fp_is_bit_set(a, b);
+}
+
+int mp_set_bit(mp_int *a, mp_digit b)
+{
+ return fp_set_bit(a, b);
+}
+
+#if defined(WOLFSSL_KEY_GEN) || defined (HAVE_ECC) || !defined(NO_DH) || \
+ !defined(NO_DSA) || !defined(NO_RSA)
+
+/* c = a * a (mod b) */
+int fp_sqrmod(fp_int *a, fp_int *b, fp_int *c)
+{
+ int err;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init(t);
+ err = fp_sqr(a, t);
+ if (err == FP_OKAY) {
+ #if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ if (c->size < FP_SIZE) {
+ err = fp_mod(t, b, t);
+ fp_copy(t, c);
+ }
+ else
+ #endif
+ {
+ err = fp_mod(t, b, c);
+ }
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return err;
+}
+
+/* fast math conversion */
+int mp_sqrmod(mp_int *a, mp_int *b, mp_int *c)
+{
+ return fp_sqrmod(a, b, c);
+}
+
+/* fast math conversion */
+int mp_montgomery_calc_normalization(mp_int *a, mp_int *b)
+{
+ fp_montgomery_calc_normalization(a, b);
+ return MP_OKAY;
+}
+
+#endif /* WOLFSSL_KEYGEN || HAVE_ECC */
+
+
+#if defined(WC_MP_TO_RADIX) || !defined(NO_DH) || !defined(NO_DSA) || \
+ !defined(NO_RSA)
+
+#ifdef WOLFSSL_KEY_GEN
+/* swap the elements of two integers, for cases where you can't simply swap the
+ * mp_int pointers around
+ */
+static int fp_exch (fp_int * a, fp_int * b)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ *t = *a;
+ *a = *b;
+ *b = *t;
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+#endif
+
+static const int lnz[16] = {
+ 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0
+};
+
+/* Counts the number of lsbs which are zero before the first zero bit */
+int fp_cnt_lsb(fp_int *a)
+{
+ int x;
+ fp_digit q, qq;
+
+ /* easy out */
+ if (fp_iszero(a) == FP_YES) {
+ return 0;
+ }
+
+ /* scan lower digits until non-zero */
+ for (x = 0; x < a->used && a->dp[x] == 0; x++) {}
+ q = a->dp[x];
+ x *= DIGIT_BIT;
+
+ /* now scan this digit until a 1 is found */
+ if ((q & 1) == 0) {
+ do {
+ qq = q & 15;
+ x += lnz[qq];
+ q >>= 4;
+ } while (qq == 0);
+ }
+ return x;
+}
+
+
+static int s_is_power_of_two(fp_digit b, int *p)
+{
+ int x;
+
+ /* fast return if no power of two */
+ if ((b==0) || (b & (b-1))) {
+ return FP_NO;
+ }
+
+ for (x = 0; x < DIGIT_BIT; x++) {
+ if (b == (((fp_digit)1)<<x)) {
+ *p = x;
+ return FP_YES;
+ }
+ }
+ return FP_NO;
+}
+
+/* a/b => cb + d == a */
+static int fp_div_d(fp_int *a, fp_digit b, fp_int *c, fp_digit *d)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int q[1];
+#else
+ fp_int *q;
+#endif
+ fp_word w;
+ fp_digit t;
+ int ix;
+
+ /* cannot divide by zero */
+ if (b == 0) {
+ return FP_VAL;
+ }
+
+ /* quick outs */
+ if (b == 1 || fp_iszero(a) == FP_YES) {
+ if (d != NULL) {
+ *d = 0;
+ }
+ if (c != NULL) {
+ fp_copy(a, c);
+ }
+ return FP_OKAY;
+ }
+
+ /* power of two ? */
+ if (s_is_power_of_two(b, &ix) == FP_YES) {
+ if (d != NULL) {
+ *d = a->dp[0] & ((((fp_digit)1)<<ix) - 1);
+ }
+ if (c != NULL) {
+ fp_div_2d(a, ix, c, NULL);
+ }
+ return FP_OKAY;
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ q = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (q == NULL)
+ return FP_MEM;
+#endif
+
+ fp_init(q);
+
+ if (c != NULL) {
+ q->used = a->used;
+ q->sign = a->sign;
+ }
+
+ w = 0;
+ for (ix = a->used - 1; ix >= 0; ix--) {
+ w = (w << ((fp_word)DIGIT_BIT)) | ((fp_word)a->dp[ix]);
+
+ if (w >= b) {
+ t = (fp_digit)(w / b);
+ w -= ((fp_word)t) * ((fp_word)b);
+ } else {
+ t = 0;
+ }
+ if (c != NULL)
+ q->dp[ix] = (fp_digit)t;
+ }
+
+ if (d != NULL) {
+ *d = (fp_digit)w;
+ }
+
+ if (c != NULL) {
+ fp_clamp(q);
+ fp_copy(q, c);
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(q, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+
+/* c = a mod b, 0 <= c < b */
+static int fp_mod_d(fp_int *a, fp_digit b, fp_digit *c)
+{
+ return fp_div_d(a, b, NULL, c);
+}
+
+int mp_mod_d(fp_int *a, fp_digit b, fp_digit *c)
+{
+ return fp_mod_d(a, b, c);
+}
+
+#endif /* WC_MP_TO_RADIX || !NO_DH || !NO_DSA || !NO_RSA */
+
+
+#if !defined(NO_DH) || !defined(NO_DSA) || !defined(NO_RSA) || \
+ defined(WOLFSSL_KEY_GEN)
+
+static int fp_isprime_ex(fp_int *a, int t, int* result);
+
+
+int mp_prime_is_prime(mp_int* a, int t, int* result)
+{
+ return fp_isprime_ex(a, t, result);
+}
+
+/* Miller-Rabin test of "a" to the base of "b" as described in
+ * HAC pp. 139 Algorithm 4.24
+ *
+ * Sets result to 0 if definitely composite or 1 if probably prime.
+ * Randomly the chance of error is no more than 1/4 and often
+ * very much lower.
+ */
+static int fp_prime_miller_rabin_ex(fp_int * a, fp_int * b, int *result,
+ fp_int *n1, fp_int *y, fp_int *r)
+{
+ int s, j;
+ int err;
+
+ /* default */
+ *result = FP_NO;
+
+ /* ensure b > 1 */
+ if (fp_cmp_d(b, 1) != FP_GT) {
+ return FP_OKAY;
+ }
+
+ /* get n1 = a - 1 */
+ fp_copy(a, n1);
+ err = fp_sub_d(n1, 1, n1);
+ if (err != FP_OKAY) {
+ return err;
+ }
+
+ /* set 2**s * r = n1 */
+ fp_copy(n1, r);
+
+ /* count the number of least significant bits
+ * which are zero
+ */
+ s = fp_cnt_lsb(r);
+
+ /* now divide n - 1 by 2**s */
+ fp_div_2d (r, s, r, NULL);
+
+ /* compute y = b**r mod a */
+ fp_zero(y);
+#if (defined(WOLFSSL_HAVE_SP_RSA) && !defined(WOLFSSL_RSA_PUBLIC_ONLY)) || \
+ defined(WOLFSSL_HAVE_SP_DH)
+#ifndef WOLFSSL_SP_NO_2048
+ if (fp_count_bits(a) == 1024)
+ sp_ModExp_1024(b, r, a, y);
+ else if (fp_count_bits(a) == 2048)
+ sp_ModExp_2048(b, r, a, y);
+ else
+#endif
+#ifndef WOLFSSL_SP_NO_3072
+ if (fp_count_bits(a) == 1536)
+ sp_ModExp_1536(b, r, a, y);
+ else if (fp_count_bits(a) == 3072)
+ sp_ModExp_3072(b, r, a, y);
+ else
+#endif
+#ifdef WOLFSSL_SP_4096
+ if (fp_count_bits(a) == 4096)
+ sp_ModExp_4096(b, r, a, y);
+ else
+#endif
+#endif
+ fp_exptmod(b, r, a, y);
+
+ /* if y != 1 and y != n1 do */
+ if (fp_cmp_d (y, 1) != FP_EQ && fp_cmp (y, n1) != FP_EQ) {
+ j = 1;
+ /* while j <= s-1 and y != n1 */
+ while ((j <= (s - 1)) && fp_cmp (y, n1) != FP_EQ) {
+ fp_sqrmod (y, a, y);
+
+ /* if y == 1 then composite */
+ if (fp_cmp_d (y, 1) == FP_EQ) {
+ return FP_OKAY;
+ }
+ ++j;
+ }
+
+ /* if y != n1 then composite */
+ if (fp_cmp (y, n1) != FP_EQ) {
+ return FP_OKAY;
+ }
+ }
+
+ /* probably prime now */
+ *result = FP_YES;
+
+ return FP_OKAY;
+}
+
+static int fp_prime_miller_rabin(fp_int * a, fp_int * b, int *result)
+{
+ int err;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int n1[1], y[1], r[1];
+#else
+ fp_int *n1, *y, *r;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ n1 = (fp_int*)XMALLOC(sizeof(fp_int) * 3, NULL, DYNAMIC_TYPE_BIGINT);
+ if (n1 == NULL) {
+ return FP_MEM;
+ }
+ y = &n1[1]; r = &n1[2];
+#endif
+
+ fp_init(n1);
+ fp_init(y);
+ fp_init(r);
+
+ err = fp_prime_miller_rabin_ex(a, b, result, n1, y, r);
+
+ fp_clear(n1);
+ fp_clear(y);
+ fp_clear(r);
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(n1, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+
+ return err;
+}
+
+
+/* a few primes */
+static const fp_digit primes[FP_PRIME_SIZE] = {
+ 0x0002, 0x0003, 0x0005, 0x0007, 0x000B, 0x000D, 0x0011, 0x0013,
+ 0x0017, 0x001D, 0x001F, 0x0025, 0x0029, 0x002B, 0x002F, 0x0035,
+ 0x003B, 0x003D, 0x0043, 0x0047, 0x0049, 0x004F, 0x0053, 0x0059,
+ 0x0061, 0x0065, 0x0067, 0x006B, 0x006D, 0x0071, 0x007F, 0x0083,
+ 0x0089, 0x008B, 0x0095, 0x0097, 0x009D, 0x00A3, 0x00A7, 0x00AD,
+ 0x00B3, 0x00B5, 0x00BF, 0x00C1, 0x00C5, 0x00C7, 0x00D3, 0x00DF,
+ 0x00E3, 0x00E5, 0x00E9, 0x00EF, 0x00F1, 0x00FB, 0x0101, 0x0107,
+ 0x010D, 0x010F, 0x0115, 0x0119, 0x011B, 0x0125, 0x0133, 0x0137,
+
+ 0x0139, 0x013D, 0x014B, 0x0151, 0x015B, 0x015D, 0x0161, 0x0167,
+ 0x016F, 0x0175, 0x017B, 0x017F, 0x0185, 0x018D, 0x0191, 0x0199,
+ 0x01A3, 0x01A5, 0x01AF, 0x01B1, 0x01B7, 0x01BB, 0x01C1, 0x01C9,
+ 0x01CD, 0x01CF, 0x01D3, 0x01DF, 0x01E7, 0x01EB, 0x01F3, 0x01F7,
+ 0x01FD, 0x0209, 0x020B, 0x021D, 0x0223, 0x022D, 0x0233, 0x0239,
+ 0x023B, 0x0241, 0x024B, 0x0251, 0x0257, 0x0259, 0x025F, 0x0265,
+ 0x0269, 0x026B, 0x0277, 0x0281, 0x0283, 0x0287, 0x028D, 0x0293,
+ 0x0295, 0x02A1, 0x02A5, 0x02AB, 0x02B3, 0x02BD, 0x02C5, 0x02CF,
+
+ 0x02D7, 0x02DD, 0x02E3, 0x02E7, 0x02EF, 0x02F5, 0x02F9, 0x0301,
+ 0x0305, 0x0313, 0x031D, 0x0329, 0x032B, 0x0335, 0x0337, 0x033B,
+ 0x033D, 0x0347, 0x0355, 0x0359, 0x035B, 0x035F, 0x036D, 0x0371,
+ 0x0373, 0x0377, 0x038B, 0x038F, 0x0397, 0x03A1, 0x03A9, 0x03AD,
+ 0x03B3, 0x03B9, 0x03C7, 0x03CB, 0x03D1, 0x03D7, 0x03DF, 0x03E5,
+ 0x03F1, 0x03F5, 0x03FB, 0x03FD, 0x0407, 0x0409, 0x040F, 0x0419,
+ 0x041B, 0x0425, 0x0427, 0x042D, 0x043F, 0x0443, 0x0445, 0x0449,
+ 0x044F, 0x0455, 0x045D, 0x0463, 0x0469, 0x047F, 0x0481, 0x048B,
+
+ 0x0493, 0x049D, 0x04A3, 0x04A9, 0x04B1, 0x04BD, 0x04C1, 0x04C7,
+ 0x04CD, 0x04CF, 0x04D5, 0x04E1, 0x04EB, 0x04FD, 0x04FF, 0x0503,
+ 0x0509, 0x050B, 0x0511, 0x0515, 0x0517, 0x051B, 0x0527, 0x0529,
+ 0x052F, 0x0551, 0x0557, 0x055D, 0x0565, 0x0577, 0x0581, 0x058F,
+ 0x0593, 0x0595, 0x0599, 0x059F, 0x05A7, 0x05AB, 0x05AD, 0x05B3,
+ 0x05BF, 0x05C9, 0x05CB, 0x05CF, 0x05D1, 0x05D5, 0x05DB, 0x05E7,
+ 0x05F3, 0x05FB, 0x0607, 0x060D, 0x0611, 0x0617, 0x061F, 0x0623,
+ 0x062B, 0x062F, 0x063D, 0x0641, 0x0647, 0x0649, 0x064D, 0x0653
+};
+
+int fp_isprime_ex(fp_int *a, int t, int* result)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int b[1];
+#else
+ fp_int *b;
+#endif
+ fp_digit d;
+ int r, res;
+
+ if (t <= 0 || t > FP_PRIME_SIZE) {
+ *result = FP_NO;
+ return FP_VAL;
+ }
+
+ if (fp_isone(a)) {
+ *result = FP_NO;
+ return FP_OKAY;
+ }
+
+ /* check against primes table */
+ for (r = 0; r < FP_PRIME_SIZE; r++) {
+ if (fp_cmp_d(a, primes[r]) == FP_EQ) {
+ *result = FP_YES;
+ return FP_OKAY;
+ }
+ }
+
+ /* do trial division */
+ for (r = 0; r < FP_PRIME_SIZE; r++) {
+ res = fp_mod_d(a, primes[r], &d);
+ if (res != MP_OKAY || d == 0) {
+ *result = FP_NO;
+ return FP_OKAY;
+ }
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ b = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (b == NULL)
+ return FP_MEM;
+#endif
+ /* now do 't' miller rabins */
+ fp_init(b);
+ for (r = 0; r < t; r++) {
+ fp_set(b, primes[r]);
+ fp_prime_miller_rabin(a, b, &res);
+ if (res == FP_NO) {
+ *result = FP_NO;
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(b, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return FP_OKAY;
+ }
+ }
+ *result = FP_YES;
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(b, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+
+int mp_prime_is_prime_ex(mp_int* a, int t, int* result, WC_RNG* rng)
+{
+ int ret = FP_YES;
+ fp_digit d;
+ int i;
+
+ if (a == NULL || result == NULL || rng == NULL)
+ return FP_VAL;
+
+ if (fp_isone(a)) {
+ *result = FP_NO;
+ return FP_OKAY;
+ }
+
+ /* check against primes table */
+ for (i = 0; i < FP_PRIME_SIZE; i++) {
+ if (fp_cmp_d(a, primes[i]) == FP_EQ) {
+ *result = FP_YES;
+ return FP_OKAY;
+ }
+ }
+
+ /* do trial division */
+ for (i = 0; i < FP_PRIME_SIZE; i++) {
+ if (fp_mod_d(a, primes[i], &d) == MP_OKAY) {
+ if (d == 0) {
+ *result = FP_NO;
+ return FP_OKAY;
+ }
+ }
+ else
+ return FP_VAL;
+ }
+
+#ifndef WC_NO_RNG
+ /* now do a miller rabin with up to t random numbers, this should
+ * give a (1/4)^t chance of a false prime. */
+ {
+ #ifndef WOLFSSL_SMALL_STACK
+ fp_int b[1], c[1], n1[1], y[1], r[1];
+ byte base[FP_MAX_PRIME_SIZE];
+ #else
+ fp_int *b, *c, *n1, *y, *r;
+ byte* base;
+ #endif
+ word32 baseSz;
+ int err;
+
+ baseSz = fp_count_bits(a);
+ /* The base size is the number of bits / 8. One is added if the number
+ * of bits isn't an even 8. */
+ baseSz = (baseSz / 8) + ((baseSz % 8) ? 1 : 0);
+
+ #ifndef WOLFSSL_SMALL_STACK
+ if (baseSz > sizeof(base))
+ return FP_MEM;
+ #else
+ base = (byte*)XMALLOC(baseSz, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ if (base == NULL)
+ return FP_MEM;
+
+ b = (fp_int*)XMALLOC(sizeof(fp_int) * 5, NULL, DYNAMIC_TYPE_BIGINT);
+ if (b == NULL) {
+ return FP_MEM;
+ }
+ c = &b[1]; n1 = &b[2]; y= &b[3]; r = &b[4];
+ #endif
+
+ fp_init(b);
+ fp_init(c);
+ fp_init(n1);
+ fp_init(y);
+ fp_init(r);
+
+ err = fp_sub_d(a, 2, c);
+ if (err != FP_OKAY) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(b, NULL, DYNAMIC_TYPE_BIGINT);
+ XFREE(base, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+ while (t > 0) {
+ if ((err = wc_RNG_GenerateBlock(rng, base, baseSz)) != 0) {
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(b, NULL, DYNAMIC_TYPE_BIGINT);
+ XFREE(base, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ return err;
+ }
+
+ fp_read_unsigned_bin(b, base, baseSz);
+ if (fp_cmp_d(b, 2) != FP_GT || fp_cmp(b, c) != FP_LT) {
+ continue;
+ }
+
+ fp_prime_miller_rabin_ex(a, b, &ret, n1, y, r);
+ if (ret == FP_NO)
+ break;
+ fp_zero(b);
+ t--;
+ }
+
+ fp_clear(n1);
+ fp_clear(y);
+ fp_clear(r);
+ fp_clear(b);
+ fp_clear(c);
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(b, NULL, DYNAMIC_TYPE_BIGINT);
+ XFREE(base, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+ #endif
+ }
+#else
+ (void)t;
+#endif /* !WC_NO_RNG */
+
+ *result = ret;
+ return FP_OKAY;
+}
+#endif /* !NO_RSA || !NO_DSA || !NO_DH || WOLFSSL_KEY_GEN */
+
+
+#ifdef WOLFSSL_KEY_GEN
+
+static int fp_gcd(fp_int *a, fp_int *b, fp_int *c);
+static int fp_lcm(fp_int *a, fp_int *b, fp_int *c);
+static int fp_randprime(fp_int* N, int len, WC_RNG* rng, void* heap);
+
+int mp_gcd(fp_int *a, fp_int *b, fp_int *c)
+{
+ return fp_gcd(a, b, c);
+}
+
+
+int mp_lcm(fp_int *a, fp_int *b, fp_int *c)
+{
+ return fp_lcm(a, b, c);
+}
+
+int mp_rand_prime(mp_int* N, int len, WC_RNG* rng, void* heap)
+{
+ int err;
+
+ err = fp_randprime(N, len, rng, heap);
+ switch(err) {
+ case FP_VAL:
+ return MP_VAL;
+ case FP_MEM:
+ return MP_MEM;
+ default:
+ break;
+ }
+
+ return MP_OKAY;
+}
+
+int mp_exch (mp_int * a, mp_int * b)
+{
+ return fp_exch(a, b);
+}
+
+
+
+int fp_randprime(fp_int* N, int len, WC_RNG* rng, void* heap)
+{
+ static const int USE_BBS = 1;
+ int err, type;
+ int isPrime = FP_YES;
+ /* Assume the candidate is probably prime and then test until
+ * it is proven composite. */
+ byte* buf;
+
+ (void)heap;
+
+ /* get type */
+ if (len < 0) {
+ type = USE_BBS;
+ len = -len;
+ } else {
+ type = 0;
+ }
+
+ /* allow sizes between 2 and 512 bytes for a prime size */
+ if (len < 2 || len > 512) {
+ return FP_VAL;
+ }
+
+ /* allocate buffer to work with */
+ buf = (byte*)XMALLOC(len, heap, DYNAMIC_TYPE_TMP_BUFFER);
+ if (buf == NULL) {
+ return FP_MEM;
+ }
+ XMEMSET(buf, 0, len);
+
+ do {
+#ifdef SHOW_GEN
+ printf(".");
+ fflush(stdout);
+#endif
+ /* generate value */
+ err = wc_RNG_GenerateBlock(rng, buf, len);
+ if (err != 0) {
+ XFREE(buf, heap, DYNAMIC_TYPE_TMP_BUFFER);
+ return FP_VAL;
+ }
+
+ /* munge bits */
+ buf[0] |= 0x80 | 0x40;
+ buf[len-1] |= 0x01 | ((type & USE_BBS) ? 0x02 : 0x00);
+
+ /* load value */
+ fp_read_unsigned_bin(N, buf, len);
+
+ /* test */
+ /* Running Miller-Rabin up to 3 times gives us a 2^{-80} chance
+ * of a 1024-bit candidate being a false positive, when it is our
+ * prime candidate. (Note 4.49 of Handbook of Applied Cryptography.)
+ * Using 8 because we've always used 8 */
+ mp_prime_is_prime_ex(N, 8, &isPrime, rng);
+ } while (isPrime == FP_NO);
+
+ XMEMSET(buf, 0, len);
+ XFREE(buf, heap, DYNAMIC_TYPE_TMP_BUFFER);
+
+ return FP_OKAY;
+}
+
+/* c = [a, b] */
+int fp_lcm(fp_int *a, fp_int *b, fp_int *c)
+{
+ int err;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[2];
+#else
+ fp_int *t;
+#endif
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int) * 2, NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL) {
+ return FP_MEM;
+ }
+#endif
+
+ fp_init(&t[0]);
+ fp_init(&t[1]);
+ err = fp_gcd(a, b, &t[0]);
+ if (err == FP_OKAY) {
+ if (fp_cmp_mag(a, b) == FP_GT) {
+ err = fp_div(a, &t[0], &t[1], NULL);
+ if (err == FP_OKAY)
+ err = fp_mul(b, &t[1], c);
+ } else {
+ err = fp_div(b, &t[0], &t[1], NULL);
+ if (err == FP_OKAY)
+ err = fp_mul(a, &t[1], c);
+ }
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return err;
+}
+
+
+
+/* c = (a, b) */
+int fp_gcd(fp_int *a, fp_int *b, fp_int *c)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int u[1], v[1], r[1];
+#else
+ fp_int *u, *v, *r;
+#endif
+
+ /* either zero than gcd is the largest */
+ if (fp_iszero (a) == FP_YES && fp_iszero (b) == FP_NO) {
+ fp_abs (b, c);
+ return FP_OKAY;
+ }
+ if (fp_iszero (a) == FP_NO && fp_iszero (b) == FP_YES) {
+ fp_abs (a, c);
+ return FP_OKAY;
+ }
+
+ /* optimized. At this point if a == 0 then
+ * b must equal zero too
+ */
+ if (fp_iszero (a) == FP_YES) {
+ fp_zero(c);
+ return FP_OKAY;
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ u = (fp_int*)XMALLOC(sizeof(fp_int) * 3, NULL, DYNAMIC_TYPE_BIGINT);
+ if (u == NULL) {
+ return FP_MEM;
+ }
+ v = &u[1]; r = &u[2];
+#endif
+
+ /* sort inputs */
+ if (fp_cmp_mag(a, b) != FP_LT) {
+ fp_init_copy(u, a);
+ fp_init_copy(v, b);
+ } else {
+ fp_init_copy(u, b);
+ fp_init_copy(v, a);
+ }
+
+ u->sign = FP_ZPOS;
+ v->sign = FP_ZPOS;
+
+ fp_init(r);
+ while (fp_iszero(v) == FP_NO) {
+ fp_mod(u, v, r);
+ fp_copy(v, u);
+ fp_copy(r, v);
+ }
+ fp_copy(u, c);
+
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(u, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+#endif /* WOLFSSL_KEY_GEN */
+
+
+#if defined(HAVE_ECC) || !defined(NO_PWDBASED) || defined(OPENSSL_EXTRA) || \
+ defined(WC_RSA_BLINDING) || !defined(NO_DSA) || \
+ (!defined(NO_RSA) && !defined(NO_RSA_BOUNDS_CHECK))
+/* c = a + b */
+void fp_add_d(fp_int *a, fp_digit b, fp_int *c)
+{
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int tmp;
+ fp_init(&tmp);
+ fp_set(&tmp, b);
+ fp_add(a, &tmp, c);
+#else
+ int i;
+ fp_word t = b;
+
+ fp_copy(a, c);
+ for (i = 0; t != 0 && i < FP_SIZE && i < c->used; i++) {
+ t += c->dp[i];
+ c->dp[i] = (fp_digit)t;
+ t >>= DIGIT_BIT;
+ }
+ if (i == c->used && i < FP_SIZE && t != 0) {
+ c->dp[i] = t;
+ c->used++;
+ }
+#endif
+}
+
+/* external compatibility */
+int mp_add_d(fp_int *a, fp_digit b, fp_int *c)
+{
+ fp_add_d(a, b, c);
+ return MP_OKAY;
+}
+
+#endif /* HAVE_ECC || !NO_PWDBASED || OPENSSL_EXTRA || WC_RSA_BLINDING ||
+ !NO_DSA || (!NO_RSA && !NO_RSA_BOUNDS_CHECK) */
+
+
+#if !defined(NO_DSA) || defined(HAVE_ECC) || defined(WOLFSSL_KEY_GEN) || \
+ defined(HAVE_COMP_KEY) || defined(WOLFSSL_DEBUG_MATH) || \
+ defined(DEBUG_WOLFSSL) || defined(OPENSSL_EXTRA) || defined(WC_MP_TO_RADIX)
+
+/* chars used in radix conversions */
+static wcchar fp_s_rmap = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "abcdefghijklmnopqrstuvwxyz+/";
+#endif
+
+#if !defined(NO_DSA) || defined(HAVE_ECC)
+#if DIGIT_BIT == 64 || DIGIT_BIT == 32
+static int fp_read_radix_16(fp_int *a, const char *str)
+{
+ int i, j, k, neg;
+ char ch;
+
+ /* if the leading digit is a
+ * minus set the sign to negative.
+ */
+ if (*str == '-') {
+ ++str;
+ neg = FP_NEG;
+ } else {
+ neg = FP_ZPOS;
+ }
+
+ j = 0;
+ k = 0;
+ for (i = (int)(XSTRLEN(str) - 1); i >= 0; i--) {
+ ch = str[i];
+ if (ch >= '0' && ch <= '9')
+ ch -= '0';
+ else if (ch >= 'A' && ch <= 'F')
+ ch -= 'A' - 10;
+ else if (ch >= 'a' && ch <= 'f')
+ ch -= 'a' - 10;
+ else
+ return FP_VAL;
+
+ a->dp[k] |= ((fp_digit)ch) << j;
+ j += 4;
+ k += j == DIGIT_BIT;
+ j &= DIGIT_BIT - 1;
+ }
+
+ a->used = k + 1;
+ fp_clamp(a);
+ /* set the sign only if a != 0 */
+ if (fp_iszero(a) != FP_YES) {
+ a->sign = neg;
+ }
+ return FP_OKAY;
+}
+#endif
+
+static int fp_read_radix(fp_int *a, const char *str, int radix)
+{
+ int y, neg;
+ char ch;
+
+ /* set the integer to the default of zero */
+ fp_zero (a);
+
+#if DIGIT_BIT == 64 || DIGIT_BIT == 32
+ if (radix == 16)
+ return fp_read_radix_16(a, str);
+#endif
+
+ /* make sure the radix is ok */
+ if (radix < 2 || radix > 64) {
+ return FP_VAL;
+ }
+
+ /* if the leading digit is a
+ * minus set the sign to negative.
+ */
+ if (*str == '-') {
+ ++str;
+ neg = FP_NEG;
+ } else {
+ neg = FP_ZPOS;
+ }
+
+ /* process each digit of the string */
+ while (*str) {
+ /* if the radix <= 36 the conversion is case insensitive
+ * this allows numbers like 1AB and 1ab to represent the same value
+ * [e.g. in hex]
+ */
+ ch = (char)((radix <= 36) ? XTOUPPER((unsigned char)*str) : *str);
+ for (y = 0; y < 64; y++) {
+ if (ch == fp_s_rmap[y]) {
+ break;
+ }
+ }
+
+ /* if the char was found in the map
+ * and is less than the given radix add it
+ * to the number, otherwise exit the loop.
+ */
+ if (y < radix) {
+ fp_mul_d (a, (fp_digit) radix, a);
+ fp_add_d (a, (fp_digit) y, a);
+ } else {
+ break;
+ }
+ ++str;
+ }
+
+ /* set the sign only if a != 0 */
+ if (fp_iszero(a) != FP_YES) {
+ a->sign = neg;
+ }
+ return FP_OKAY;
+}
+
+/* fast math conversion */
+int mp_read_radix(mp_int *a, const char *str, int radix)
+{
+ return fp_read_radix(a, str, radix);
+}
+
+#endif /* !defined(NO_DSA) || defined(HAVE_ECC) */
+
+#ifdef HAVE_ECC
+
+/* fast math conversion */
+int mp_sqr(fp_int *A, fp_int *B)
+{
+ return fp_sqr(A, B);
+}
+
+/* fast math conversion */
+int mp_montgomery_reduce(fp_int *a, fp_int *m, fp_digit mp)
+{
+ return fp_montgomery_reduce(a, m, mp);
+}
+
+
+/* fast math conversion */
+int mp_montgomery_setup(fp_int *a, fp_digit *rho)
+{
+ return fp_montgomery_setup(a, rho);
+}
+
+int mp_div_2(fp_int * a, fp_int * b)
+{
+ fp_div_2(a, b);
+ return MP_OKAY;
+}
+
+
+int mp_init_copy(fp_int * a, fp_int * b)
+{
+ fp_init_copy(a, b);
+ return MP_OKAY;
+}
+
+#ifdef HAVE_COMP_KEY
+
+int mp_cnt_lsb(fp_int* a)
+{
+ return fp_cnt_lsb(a);
+}
+
+#endif /* HAVE_COMP_KEY */
+
+#endif /* HAVE_ECC */
+
+#if defined(HAVE_ECC) || !defined(NO_RSA) || !defined(NO_DSA) || \
+ defined(WOLFSSL_KEY_GEN)
+/* fast math conversion */
+int mp_set(fp_int *a, fp_digit b)
+{
+ fp_set(a,b);
+ return MP_OKAY;
+}
+#endif
+
+#ifdef WC_MP_TO_RADIX
+
+/* returns size of ASCII representation */
+int mp_radix_size (mp_int *a, int radix, int *size)
+{
+ int res, digs;
+ fp_digit d;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+ *size = 0;
+
+ /* special case for binary */
+ if (radix == 2) {
+ *size = fp_count_bits (a) + (a->sign == FP_NEG ? 1 : 0) + 1;
+ return FP_YES;
+ }
+
+ /* make sure the radix is in range */
+ if (radix < 2 || radix > 64) {
+ return FP_VAL;
+ }
+
+ if (fp_iszero(a) == MP_YES) {
+ *size = 2;
+ return FP_OKAY;
+ }
+
+ /* digs is the digit count */
+ digs = 0;
+
+ /* if it's negative add one for the sign */
+ if (a->sign == FP_NEG) {
+ ++digs;
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ /* init a copy of the input */
+ fp_init_copy (t, a);
+
+ /* force temp to positive */
+ t->sign = FP_ZPOS;
+
+ /* fetch out all of the digits */
+ while (fp_iszero (t) == FP_NO) {
+ if ((res = fp_div_d (t, (mp_digit) radix, t, &d)) != FP_OKAY) {
+ fp_zero (t);
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return res;
+ }
+ ++digs;
+ }
+ fp_zero (t);
+
+ /* return digs + 1, the 1 is for the NULL byte that would be required. */
+ *size = digs + 1;
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+/* stores a bignum as a ASCII string in a given radix (2..64) */
+int mp_toradix (mp_int *a, char *str, int radix)
+{
+ int res, digs;
+ fp_digit d;
+ char *_s = str;
+#ifndef WOLFSSL_SMALL_STACK
+ fp_int t[1];
+#else
+ fp_int *t;
+#endif
+
+ /* check range of the radix */
+ if (radix < 2 || radix > 64) {
+ return FP_VAL;
+ }
+
+ /* quick out if its zero */
+ if (fp_iszero(a) == FP_YES) {
+ *str++ = '0';
+ *str = '\0';
+ return FP_OKAY;
+ }
+
+#ifdef WOLFSSL_SMALL_STACK
+ t = (fp_int*)XMALLOC(sizeof(fp_int), NULL, DYNAMIC_TYPE_BIGINT);
+ if (t == NULL)
+ return FP_MEM;
+#endif
+
+ /* init a copy of the input */
+ fp_init_copy (t, a);
+
+ /* if it is negative output a - */
+ if (t->sign == FP_NEG) {
+ ++_s;
+ *str++ = '-';
+ t->sign = FP_ZPOS;
+ }
+
+ digs = 0;
+ while (fp_iszero (t) == FP_NO) {
+ if ((res = fp_div_d (t, (fp_digit) radix, t, &d)) != FP_OKAY) {
+ fp_zero (t);
+ #ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+ #endif
+ return res;
+ }
+ *str++ = fp_s_rmap[d];
+ ++digs;
+ }
+#ifndef WC_DISABLE_RADIX_ZERO_PAD
+ /* For hexadecimal output, add zero padding when number of digits is odd */
+ if ((digs & 1) && (radix == 16)) {
+ *str++ = fp_s_rmap[0];
+ ++digs;
+ }
+#endif
+ /* reverse the digits of the string. In this case _s points
+ * to the first digit [excluding the sign] of the number]
+ */
+ fp_reverse ((unsigned char *)_s, digs);
+
+ /* append a NULL so the string is properly terminated */
+ *str = '\0';
+
+ fp_zero (t);
+#ifdef WOLFSSL_SMALL_STACK
+ XFREE(t, NULL, DYNAMIC_TYPE_BIGINT);
+#endif
+ return FP_OKAY;
+}
+
+#ifdef WOLFSSL_DEBUG_MATH
+void mp_dump(const char* desc, mp_int* a, byte verbose)
+{
+ char buffer[FP_SIZE * sizeof(fp_digit) * 2];
+ int size;
+
+#if defined(ALT_ECC_SIZE) || defined(HAVE_WOLF_BIGINT)
+ size = a->size;
+#else
+ size = FP_SIZE;
+#endif
+
+ printf("%s: ptr=%p, used=%d, sign=%d, size=%d, fpd=%d\n",
+ desc, a, a->used, a->sign, size, (int)sizeof(fp_digit));
+
+ mp_tohex(a, buffer);
+ printf(" %s\n ", buffer);
+
+ if (verbose) {
+ int i;
+ for(i=0; i<size * (int)sizeof(fp_digit); i++) {
+ printf("%x ", *(((byte*)a->dp) + i));
+ }
+ printf("\n");
+ }
+}
+#endif /* WOLFSSL_DEBUG_MATH */
+
+#endif /* WC_MP_TO_RADIX */
+
+
+int mp_abs(mp_int* a, mp_int* b)
+{
+ fp_abs(a, b);
+ return FP_OKAY;
+}
+
+
+int mp_lshd (mp_int * a, int b)
+{
+ fp_lshd(a, b);
+ return FP_OKAY;
+}
+
+#endif /* USE_FAST_MATH */
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