-/* crypto/asn1/a_int.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.
+/*
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
*
- * 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.]
+ * Licensed under the OpenSSL license (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
*/
#include <stdio.h>
* followed by optional zeros isn't padded.
*/
+/*
+ * If |pad| is zero, the operation is effectively reduced to memcpy,
+ * and if |pad| is 0xff, then it performs two's complement, ~dst + 1.
+ * Note that in latter case sequence of zeros yields itself, and so
+ * does 0x80 followed by any number of zeros. These properties are
+ * used elsewhere below...
+ */
+static void twos_complement(unsigned char *dst, const unsigned char *src,
+ size_t len, unsigned char pad)
+{
+ unsigned int carry = pad & 1;
+
+ /* Begin at the end of the encoding */
+ dst += len;
+ src += len;
+ /* two's complement value: ~value + 1 */
+ while (len-- != 0) {
+ *(--dst) = (unsigned char)(carry += *(--src) ^ pad);
+ carry >>= 8;
+ }
+}
+
static size_t i2c_ibuf(const unsigned char *b, size_t blen, int neg,
unsigned char **pp)
{
- int pad = 0;
+ unsigned int pad = 0;
size_t ret, i;
unsigned char *p, pb = 0;
- const unsigned char *n;
- if (b == NULL || blen == 0)
- ret = 1;
- else {
+ if (b != NULL && blen) {
ret = blen;
i = b[0];
- if (ret == 1 && i == 0)
- neg = 0;
if (!neg && (i > 127)) {
pad = 1;
pb = 0;
} else if (neg) {
+ pb = 0xFF;
if (i > 128) {
pad = 1;
- pb = 0xFF;
} else if (i == 128) {
/*
- * Special case: if any other bytes non zero we pad:
- * otherwise we don't.
+ * Special case [of minimal negative for given length]:
+ * if any other bytes non zero we pad, otherwise we don't.
*/
- for (i = 1; i < blen; i++)
- if (b[i]) {
- pad = 1;
- pb = 0xFF;
- break;
- }
+ for (pad = 0, i = 1; i < blen; i++)
+ pad |= b[i];
+ pb = pad != 0 ? 0xffU : 0;
+ pad = pb & 1;
}
}
ret += pad;
+ } else {
+ ret = 1;
+ blen = 0; /* reduce '(b == NULL || blen == 0)' to '(blen == 0)' */
}
- if (pp == NULL)
+
+ if (pp == NULL || (p = *pp) == NULL)
return ret;
- p = *pp;
- if (pad)
- *(p++) = pb;
- if (b == NULL || blen == 0)
- *p = 0;
- else if (!neg)
- memcpy(p, b, blen);
- else {
- /* Begin at the end of the encoding */
- n = b + blen - 1;
- p += blen - 1;
- i = blen;
- /* Copy zeros to destination as long as source is zero */
- while (!*n && i > 1) {
- *(p--) = 0;
- n--;
- i--;
- }
- /* Complement and increment next octet */
- *(p--) = ((*(n--)) ^ 0xff) + 1;
- i--;
- /* Complement any octets left */
- for (; i > 0; i--)
- *(p--) = *(n--) ^ 0xff;
- }
+ /*
+ * This magically handles all corner cases, such as '(b == NULL ||
+ * blen == 0)', non-negative value, "negative" zero, 0x80 followed
+ * by any number of zeros...
+ */
+ *p = pb;
+ p += pad; /* yes, p[0] can be written twice, but it's little
+ * price to pay for eliminated branches */
+ twos_complement(p, b, blen, pb);
*pp += ret;
return ret;
/*
* convert content octets into a big endian buffer. Returns the length
- * of buffer or 0 on error: for malformed INTEGER. If output bufer is
+ * of buffer or 0 on error: for malformed INTEGER. If output buffer is
* NULL just return length.
*/
static size_t c2i_ibuf(unsigned char *b, int *pneg,
const unsigned char *p, size_t plen)
{
- size_t i;
int neg, pad;
/* Zero content length is illegal */
if (plen == 0) {
*pneg = neg;
/* Handle common case where length is 1 octet separately */
if (plen == 1) {
- if (b) {
+ if (b != NULL) {
if (neg)
b[0] = (p[0] ^ 0xFF) + 1;
else
ASN1err(ASN1_F_C2I_IBUF, ASN1_R_ILLEGAL_PADDING);
return 0;
}
- /* If positive just copy across */
- if (neg == 0) {
- if (b)
- memcpy(b, p + pad, plen - pad);
- return plen - pad;
- }
-
- if (neg && pad) {
- /* check is any following octets are non zero */
- for (i = 1; i < plen; i++) {
- if (p[i] != 0)
- break;
- }
- /* if all bytes are zero handle as special case */
- if (i == plen) {
- if (b) {
- b[0] = 1;
- memset(b + 1, 0, plen - 1);
- }
- return plen;
- }
- }
+ /* skip over pad */
+ p += pad;
plen -= pad;
- /* Must be negative: calculate twos complement */
- if (b) {
- const unsigned char *from = p + plen - 1 + pad;
- unsigned char *to = b + plen - 1;
- i = plen;
- while (*from == 0 && i) {
- *to-- = 0;
- i--;
- from--;
- }
- *to-- = (*from-- ^ 0xff) + 1;
- OPENSSL_assert(i != 0);
- i--;
- for (; i > 0; i--)
- *to-- = *from-- ^ 0xff;
- }
+
+ if (b != NULL)
+ twos_complement(b, p, plen, neg ? 0xffU : 0);
+
return plen;
}
static int asn1_get_uint64(uint64_t *pr, const unsigned char *b, size_t blen)
{
size_t i;
+ uint64_t r;
+
if (blen > sizeof(*pr)) {
ASN1err(ASN1_F_ASN1_GET_UINT64, ASN1_R_TOO_LARGE);
return 0;
}
- *pr = 0;
if (b == NULL)
return 0;
- for (i = 0; i < blen; i++) {
- *pr <<= 8;
- *pr |= b[i];
+ for (r = 0, i = 0; i < blen; i++) {
+ r <<= 8;
+ r |= b[i];
}
+ *pr = r;
return 1;
}
-static size_t asn1_put_uint64(unsigned char *b, uint64_t r)
+/*
+ * Write uint64_t to big endian buffer and return offset to first
+ * written octet. In other words it returns offset in range from 0
+ * to 7, with 0 denoting 8 written octets and 7 - one.
+ */
+static size_t asn1_put_uint64(unsigned char b[sizeof(uint64_t)], uint64_t r)
{
- if (r >= 0x100) {
- unsigned char *p;
- uint64_t rtmp = r;
- size_t i = 0;
-
- /* Work out how many bytes we need */
- while (rtmp) {
- rtmp >>= 8;
- i++;
- }
+ size_t off = sizeof(uint64_t);
- /* Copy from end to beginning */
- p = b + i - 1;
-
- do {
- *p-- = r & 0xFF;
- r >>= 8;
- } while (p >= b);
-
- return i;
- }
-
- b[0] = (unsigned char)r;
- return 1;
+ do {
+ b[--off] = (unsigned char)r;
+ } while (r >>= 8);
+ return off;
}
/*
ASN1err(ASN1_F_ASN1_GET_INT64, ASN1_R_TOO_SMALL);
return 0;
}
- *pr = -(int64_t)r;
+ *pr = 0 - (uint64_t)r;
} else {
if (r > INT64_MAX) {
ASN1err(ASN1_F_ASN1_GET_INT64, ASN1_R_TOO_LARGE);
static int asn1_string_set_int64(ASN1_STRING *a, int64_t r, int itype)
{
unsigned char tbuf[sizeof(r)];
- size_t l;
+ size_t off;
+
a->type = itype;
if (r < 0) {
- l = asn1_put_uint64(tbuf, -r);
+ off = asn1_put_uint64(tbuf, -r);
a->type |= V_ASN1_NEG;
} else {
- l = asn1_put_uint64(tbuf, r);
+ off = asn1_put_uint64(tbuf, r);
a->type &= ~V_ASN1_NEG;
}
- if (l == 0)
- return 0;
- return ASN1_STRING_set(a, tbuf, l);
+ return ASN1_STRING_set(a, tbuf + off, sizeof(tbuf) - off);
}
static int asn1_string_get_uint64(uint64_t *pr, const ASN1_STRING *a,
static int asn1_string_set_uint64(ASN1_STRING *a, uint64_t r, int itype)
{
unsigned char tbuf[sizeof(r)];
- size_t l;
+ size_t off;
+
a->type = itype;
- l = asn1_put_uint64(tbuf, r);
- if (l == 0)
- return 0;
- return ASN1_STRING_set(a, tbuf, l);
+ off = asn1_put_uint64(tbuf, r);
+ return ASN1_STRING_set(a, tbuf + off, sizeof(tbuf) - off);
}
/*
}
ret = BN_bin2bn(ai->data, ai->length, bn);
- if (ret == 0) {
+ if (ret == NULL) {
ASN1err(ASN1_F_ASN1_STRING_TO_BN, ASN1_R_BN_LIB);
return NULL;
}
return ASN1_ENUMERATED_set_int64(a, v);
}
-long ASN1_ENUMERATED_get(ASN1_ENUMERATED *a)
+long ASN1_ENUMERATED_get(const ASN1_ENUMERATED *a)
{
int i;
int64_t r;
{
return asn1_string_to_bn(ai, bn, V_ASN1_ENUMERATED);
}
+
+/* Internal functions used by x_int64.c */
+int c2i_uint64_int(uint64_t *ret, int *neg, const unsigned char **pp, long len)
+{
+ unsigned char buf[sizeof(uint64_t)];
+ size_t buflen;
+
+ buflen = c2i_ibuf(NULL, NULL, *pp, len);
+ if (buflen == 0)
+ return 0;
+ if (buflen > sizeof(uint64_t)) {
+ ASN1err(ASN1_F_C2I_UINT64_INT, ASN1_R_TOO_LARGE);
+ return 0;
+ }
+ (void)c2i_ibuf(buf, neg, *pp, len);
+ return asn1_get_uint64(ret, buf, buflen);
+}
+
+int i2c_uint64_int(unsigned char *p, uint64_t r, int neg)
+{
+ unsigned char buf[sizeof(uint64_t)];
+ size_t off;
+
+ off = asn1_put_uint64(buf, r);
+ return i2c_ibuf(buf + off, sizeof(buf) - off, neg, &p);
+}
+
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