Diff: src/wolfmath.c

Revision:

0:1387ff3eed4a

diff -r 000000000000 -r 1387ff3eed4a src/wolfmath.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/wolfmath.c	Wed Nov 20 13:28:01 2019 +0000
@@ -0,0 +1,306 @@
+/* wolfmath.c
+ *
+ * Copyright (C) 2006-2017 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
+ */
+
+
+/* common functions for either math library */
+
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
+/* in case user set USE_FAST_MATH there */
+#include <wolfcrypt/settings.h>
+
+#ifdef USE_FAST_MATH
+    #include <wolfcrypt/tfm.h>
+#else
+    #include <wolfcrypt/integer.h>
+#endif
+
+#include <wolfcrypt/error-crypt.h>
+#include <wolfcrypt/logging.h>
+
+#if defined(USE_FAST_MATH) || !defined(NO_BIG_INT)
+
+#ifdef WOLFSSL_ASYNC_CRYPT
+    #include <wolfcrypt/async.h>
+#endif
+
+#ifdef NO_INLINE
+    #include <wolfcrypt/misc.h>
+#else
+    #define WOLFSSL_MISC_INCLUDED
+    #include <wolfcrypt/src/misc.c>
+#endif
+
+
+#if !defined(WC_NO_CACHE_RESISTANT) && \
+    ((defined(HAVE_ECC) && defined(ECC_TIMING_RESISTANT)) || \
+     (defined(USE_FAST_MATH) && defined(TFM_TIMING_RESISTANT)))
+
+    /* all off / all on pointer addresses for constant calculations */
+    /* ecc.c uses same table */
+    const wolfssl_word wc_off_on_addr[2] =
+    {
+    #if defined(WC_64BIT_CPU)
+        W64LIT(0x0000000000000000),
+        W64LIT(0xffffffffffffffff)
+    #elif defined(WC_16BIT_CPU)
+        0x0000U,
+        0xffffU
+    #else
+        /* 32 bit */
+        0x00000000U,
+        0xffffffffU
+    #endif
+    };
+#endif
+
+
+int get_digit_count(mp_int* a)
+{
+    if (a == NULL)
+        return 0;
+
+    return a->used;
+}
+
+mp_digit get_digit(mp_int* a, int n)
+{
+    if (a == NULL)
+        return 0;
+
+    return (n >= a->used || n < 0) ? 0 : a->dp[n];
+}
+
+int get_rand_digit(WC_RNG* rng, mp_digit* d)
+{
+    return wc_RNG_GenerateBlock(rng, (byte*)d, sizeof(mp_digit));
+}
+
+#ifdef WC_RSA_BLINDING
+int mp_rand(mp_int* a, int digits, WC_RNG* rng)
+{
+    int ret = 0;
+    DECLARE_VAR(d, mp_digit, 1, rng->heap);
+
+    if (rng == NULL) {
+        ret = MISSING_RNG_E; goto exit;
+    }
+
+    if (a == NULL
+    #ifdef WOLFSSL_ASYNC_CRYPT
+        || d == NULL
+    #endif
+    ) {
+        ret = BAD_FUNC_ARG; goto exit;
+    }
+
+    mp_zero(a);
+    if (digits <= 0) {
+        ret = MP_OKAY; goto exit;
+    }
+
+    /* first place a random non-zero digit */
+    do {
+        ret = get_rand_digit(rng, d);
+        if (ret != 0) {
+            goto exit;
+        }
+    } while (*d == 0);
+
+    if ((ret = mp_add_d(a, *d, a)) != MP_OKAY) {
+        goto exit;
+    }
+
+    while (--digits > 0) {
+        if ((ret = mp_lshd(a, 1)) != MP_OKAY) {
+            goto exit;
+        }
+        if ((ret = get_rand_digit(rng, d)) != 0) {
+            goto exit;
+        }
+        if ((ret = mp_add_d(a, *d, a)) != MP_OKAY) {
+            goto exit;
+        }
+    }
+
+exit:
+    FREE_VAR(d, rng->heap);
+
+    return ret;
+}
+#endif /* WC_RSA_BLINDING */
+
+
+#ifdef HAVE_WOLF_BIGINT
+void wc_bigint_init(WC_BIGINT* a)
+{
+    if (a != NULL) {
+        a->buf = NULL;
+        a->len = 0;
+        a->heap = NULL;
+    }
+}
+
+int wc_bigint_alloc(WC_BIGINT* a, word32 sz)
+{
+    int err = MP_OKAY;
+
+    if (a == NULL)
+        return BAD_FUNC_ARG;
+
+    if (sz > 0) {
+        if (a->buf && sz > a->len) {
+            wc_bigint_free(a);
+        }
+        if (a->buf == NULL) {
+            a->buf = (byte*)XMALLOC(sz, a->heap, DYNAMIC_TYPE_WOLF_BIGINT);
+        }
+        if (a->buf == NULL) {
+            err = MP_MEM;
+        }
+        else {
+            XMEMSET(a->buf, 0, sz);
+        }
+    }
+    a->len = sz;
+
+    return err;
+}
+
+/* assumes input is big endian format */
+int wc_bigint_from_unsigned_bin(WC_BIGINT* a, const byte* in, word32 inlen)
+{
+    int err;
+
+    if (a == NULL || in == NULL || inlen == 0)
+        return BAD_FUNC_ARG;
+
+    err = wc_bigint_alloc(a, inlen);
+    if (err == 0) {
+        XMEMCPY(a->buf, in, inlen);
+    }
+
+    return err;
+}
+
+int wc_bigint_to_unsigned_bin(WC_BIGINT* a, byte* out, word32* outlen)
+{
+    word32 sz;
+
+    if (a == NULL || out == NULL || outlen == NULL || *outlen == 0)
+        return BAD_FUNC_ARG;
+
+    /* trim to fit into output buffer */
+    sz = a->len;
+    if (a->len > *outlen) {
+        WOLFSSL_MSG("wc_bigint_export: Truncating output");
+        sz = *outlen;
+    }
+
+    if (a->buf) {
+        XMEMCPY(out, a->buf, sz);
+    }
+
+    *outlen = sz;
+
+    return MP_OKAY;
+}
+
+void wc_bigint_zero(WC_BIGINT* a)
+{
+    if (a && a->buf) {
+        ForceZero(a->buf, a->len);
+    }
+}
+
+void wc_bigint_free(WC_BIGINT* a)
+{
+    if (a) {
+        if (a->buf) {
+          XFREE(a->buf, a->heap, DYNAMIC_TYPE_WOLF_BIGINT);
+        }
+        a->buf = NULL;
+        a->len = 0;
+    }
+}
+
+/* sz: make sure the buffer is at least that size and zero padded.
+ *     A `sz == 0` will use the size of `src`.
+ *     The calulcates sz is stored into dst->len in `wc_bigint_alloc`.
+ */
+int wc_mp_to_bigint_sz(mp_int* src, WC_BIGINT* dst, word32 sz)
+{
+    int err;
+    word32 x, y;
+
+    if (src == NULL || dst == NULL)
+        return BAD_FUNC_ARG;
+
+    /* get size of source */
+    x = mp_unsigned_bin_size(src);
+    if (sz < x)
+        sz = x;
+
+    /* make sure destination is allocated and large enough */
+    err = wc_bigint_alloc(dst, sz);
+    if (err == MP_OKAY) {
+
+        /* leading zero pad */
+        y = sz - x;
+        XMEMSET(dst->buf, 0, y);
+
+        /* export src as unsigned bin to destination buf */
+        err = mp_to_unsigned_bin(src, dst->buf + y);
+    }
+
+    return err;
+}
+
+int wc_mp_to_bigint(mp_int* src, WC_BIGINT* dst)
+{
+    if (src == NULL || dst == NULL)
+        return BAD_FUNC_ARG;
+
+    return wc_mp_to_bigint_sz(src, dst, 0);
+}
+
+int wc_bigint_to_mp(WC_BIGINT* src, mp_int* dst)
+{
+    int err;
+
+    if (src == NULL || dst == NULL)
+        return BAD_FUNC_ARG;
+
+    if (src->buf == NULL)
+        return BAD_FUNC_ARG;
+
+    err = mp_read_unsigned_bin(dst, src->buf, src->len);
+    wc_bigint_free(src);
+
+    return err;
+}
+
+#endif /* HAVE_WOLF_BIGINT */
+
+#endif /* USE_FAST_MATH || !NO_BIG_INT */
+