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Diffstat (limited to 'thirdparty/openssl/crypto/bn/bn_recp.c')
-rw-r--r--thirdparty/openssl/crypto/bn/bn_recp.c252
1 files changed, 252 insertions, 0 deletions
diff --git a/thirdparty/openssl/crypto/bn/bn_recp.c b/thirdparty/openssl/crypto/bn/bn_recp.c
new file mode 100644
index 0000000000..f047040efe
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+++ b/thirdparty/openssl/crypto/bn/bn_recp.c
@@ -0,0 +1,252 @@
+/* crypto/bn/bn_recp.c */
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to. The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code. The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * "This product includes cryptographic software written by
+ * Eric Young (eay@cryptsoft.com)"
+ * The word 'cryptographic' can be left out if the rouines from the library
+ * being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ * the apps directory (application code) you must include an acknowledgement:
+ * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed. i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.]
+ */
+
+#include <stdio.h>
+#include "cryptlib.h"
+#include "bn_lcl.h"
+
+void BN_RECP_CTX_init(BN_RECP_CTX *recp)
+{
+ BN_init(&(recp->N));
+ BN_init(&(recp->Nr));
+ recp->num_bits = 0;
+ recp->shift = 0;
+ recp->flags = 0;
+}
+
+BN_RECP_CTX *BN_RECP_CTX_new(void)
+{
+ BN_RECP_CTX *ret;
+
+ if ((ret = (BN_RECP_CTX *)OPENSSL_malloc(sizeof(BN_RECP_CTX))) == NULL)
+ return (NULL);
+
+ BN_RECP_CTX_init(ret);
+ ret->flags = BN_FLG_MALLOCED;
+ return (ret);
+}
+
+void BN_RECP_CTX_free(BN_RECP_CTX *recp)
+{
+ if (recp == NULL)
+ return;
+
+ BN_free(&(recp->N));
+ BN_free(&(recp->Nr));
+ if (recp->flags & BN_FLG_MALLOCED)
+ OPENSSL_free(recp);
+}
+
+int BN_RECP_CTX_set(BN_RECP_CTX *recp, const BIGNUM *d, BN_CTX *ctx)
+{
+ if (!BN_copy(&(recp->N), d))
+ return 0;
+ BN_zero(&(recp->Nr));
+ recp->num_bits = BN_num_bits(d);
+ recp->shift = 0;
+ return (1);
+}
+
+int BN_mod_mul_reciprocal(BIGNUM *r, const BIGNUM *x, const BIGNUM *y,
+ BN_RECP_CTX *recp, BN_CTX *ctx)
+{
+ int ret = 0;
+ BIGNUM *a;
+ const BIGNUM *ca;
+
+ BN_CTX_start(ctx);
+ if ((a = BN_CTX_get(ctx)) == NULL)
+ goto err;
+ if (y != NULL) {
+ if (x == y) {
+ if (!BN_sqr(a, x, ctx))
+ goto err;
+ } else {
+ if (!BN_mul(a, x, y, ctx))
+ goto err;
+ }
+ ca = a;
+ } else
+ ca = x; /* Just do the mod */
+
+ ret = BN_div_recp(NULL, r, ca, recp, ctx);
+ err:
+ BN_CTX_end(ctx);
+ bn_check_top(r);
+ return (ret);
+}
+
+int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
+ BN_RECP_CTX *recp, BN_CTX *ctx)
+{
+ int i, j, ret = 0;
+ BIGNUM *a, *b, *d, *r;
+
+ BN_CTX_start(ctx);
+ a = BN_CTX_get(ctx);
+ b = BN_CTX_get(ctx);
+ if (dv != NULL)
+ d = dv;
+ else
+ d = BN_CTX_get(ctx);
+ if (rem != NULL)
+ r = rem;
+ else
+ r = BN_CTX_get(ctx);
+ if (a == NULL || b == NULL || d == NULL || r == NULL)
+ goto err;
+
+ if (BN_ucmp(m, &(recp->N)) < 0) {
+ BN_zero(d);
+ if (!BN_copy(r, m)) {
+ BN_CTX_end(ctx);
+ return 0;
+ }
+ BN_CTX_end(ctx);
+ return (1);
+ }
+
+ /*
+ * We want the remainder Given input of ABCDEF / ab we need multiply
+ * ABCDEF by 3 digests of the reciprocal of ab
+ */
+
+ /* i := max(BN_num_bits(m), 2*BN_num_bits(N)) */
+ i = BN_num_bits(m);
+ j = recp->num_bits << 1;
+ if (j > i)
+ i = j;
+
+ /* Nr := round(2^i / N) */
+ if (i != recp->shift)
+ recp->shift = BN_reciprocal(&(recp->Nr), &(recp->N), i, ctx);
+ /* BN_reciprocal could have returned -1 for an error */
+ if (recp->shift == -1)
+ goto err;
+
+ /*-
+ * d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))|
+ * = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))|
+ * <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)|
+ * = |m/N|
+ */
+ if (!BN_rshift(a, m, recp->num_bits))
+ goto err;
+ if (!BN_mul(b, a, &(recp->Nr), ctx))
+ goto err;
+ if (!BN_rshift(d, b, i - recp->num_bits))
+ goto err;
+ d->neg = 0;
+
+ if (!BN_mul(b, &(recp->N), d, ctx))
+ goto err;
+ if (!BN_usub(r, m, b))
+ goto err;
+ r->neg = 0;
+
+#if 1
+ j = 0;
+ while (BN_ucmp(r, &(recp->N)) >= 0) {
+ if (j++ > 2) {
+ BNerr(BN_F_BN_DIV_RECP, BN_R_BAD_RECIPROCAL);
+ goto err;
+ }
+ if (!BN_usub(r, r, &(recp->N)))
+ goto err;
+ if (!BN_add_word(d, 1))
+ goto err;
+ }
+#endif
+
+ r->neg = BN_is_zero(r) ? 0 : m->neg;
+ d->neg = m->neg ^ recp->N.neg;
+ ret = 1;
+ err:
+ BN_CTX_end(ctx);
+ bn_check_top(dv);
+ bn_check_top(rem);
+ return (ret);
+}
+
+/*
+ * len is the expected size of the result We actually calculate with an extra
+ * word of precision, so we can do faster division if the remainder is not
+ * required.
+ */
+/* r := 2^len / m */
+int BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx)
+{
+ int ret = -1;
+ BIGNUM *t;
+
+ BN_CTX_start(ctx);
+ if ((t = BN_CTX_get(ctx)) == NULL)
+ goto err;
+
+ if (!BN_set_bit(t, len))
+ goto err;
+
+ if (!BN_div(r, NULL, t, m, ctx))
+ goto err;
+
+ ret = len;
+ err:
+ bn_check_top(r);
+ BN_CTX_end(ctx);
+ return (ret);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-02-16 12:12:53 +0000