515 lines
12 KiB
C
515 lines
12 KiB
C
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/* $OpenBSD: a_int.c,v 1.34 2019/04/28 05:03:56 tb Exp $ */
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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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* All rights reserved.
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*
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* This package is an SSL implementation written
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* by Eric Young (eay@cryptsoft.com).
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* The implementation was written so as to conform with Netscapes SSL.
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*
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* This library is free for commercial and non-commercial use as long as
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* the following conditions are aheared to. The following conditions
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* apply to all code found in this distribution, be it the RC4, RSA,
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* lhash, DES, etc., code; not just the SSL code. The SSL documentation
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* included with this distribution is covered by the same copyright terms
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* except that the holder is Tim Hudson (tjh@cryptsoft.com).
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*
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* Copyright remains Eric Young's, and as such any Copyright notices in
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* the code are not to be removed.
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* If this package is used in a product, Eric Young should be given attribution
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* as the author of the parts of the library used.
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* This can be in the form of a textual message at program startup or
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* in documentation (online or textual) provided with the package.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* "This product includes cryptographic software written by
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* Eric Young (eay@cryptsoft.com)"
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* The word 'cryptographic' can be left out if the rouines from the library
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* being used are not cryptographic related :-).
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* 4. If you include any Windows specific code (or a derivative thereof) from
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* the apps directory (application code) you must include an acknowledgement:
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* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
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*
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* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* The licence and distribution terms for any publically available version or
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* derivative of this code cannot be changed. i.e. this code cannot simply be
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* copied and put under another distribution licence
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* [including the GNU Public Licence.]
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*/
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#include <limits.h>
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#include <stdio.h>
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#include <string.h>
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#include <openssl/asn1.h>
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#include <openssl/bn.h>
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#include <openssl/err.h>
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static int
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ASN1_INTEGER_valid(const ASN1_INTEGER *a)
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{
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return (a != NULL && a->length >= 0);
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}
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ASN1_INTEGER *
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ASN1_INTEGER_dup(const ASN1_INTEGER *x)
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{
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if (!ASN1_INTEGER_valid(x))
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return NULL;
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return ASN1_STRING_dup(x);
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}
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int
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ASN1_INTEGER_cmp(const ASN1_INTEGER *x, const ASN1_INTEGER *y)
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{
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int neg, ret;
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/* Compare signs */
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neg = x->type & V_ASN1_NEG;
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if (neg != (y->type & V_ASN1_NEG)) {
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if (neg)
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return -1;
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else
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return 1;
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}
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ret = ASN1_STRING_cmp(x, y);
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if (neg)
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return -ret;
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else
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return ret;
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}
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/*
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* This converts an ASN1 INTEGER into its content encoding.
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* The internal representation is an ASN1_STRING whose data is a big endian
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* representation of the value, ignoring the sign. The sign is determined by
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* the type: V_ASN1_INTEGER for positive and V_ASN1_NEG_INTEGER for negative.
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*
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* Positive integers are no problem: they are almost the same as the DER
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* encoding, except if the first byte is >= 0x80 we need to add a zero pad.
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*
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* Negative integers are a bit trickier...
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* The DER representation of negative integers is in 2s complement form.
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* The internal form is converted by complementing each octet and finally
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* adding one to the result. This can be done less messily with a little trick.
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* If the internal form has trailing zeroes then they will become FF by the
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* complement and 0 by the add one (due to carry) so just copy as many trailing
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* zeros to the destination as there are in the source. The carry will add one
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* to the last none zero octet: so complement this octet and add one and finally
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* complement any left over until you get to the start of the string.
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*
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* Padding is a little trickier too. If the first bytes is > 0x80 then we pad
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* with 0xff. However if the first byte is 0x80 and one of the following bytes
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* is non-zero we pad with 0xff. The reason for this distinction is that 0x80
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* followed by optional zeros isn't padded.
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*/
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int
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i2c_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp)
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{
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int pad = 0, ret, i, neg;
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unsigned char *p, *n, pb = 0;
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if (!ASN1_INTEGER_valid(a))
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return 0;
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neg = a->type & V_ASN1_NEG;
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if (a->length == 0)
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ret = 1;
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else {
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ret = a->length;
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i = a->data[0];
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if (!neg && (i > 127)) {
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pad = 1;
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pb = 0;
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} else if (neg) {
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if (i > 128) {
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pad = 1;
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pb = 0xFF;
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} else if (i == 128) {
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/*
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* Special case: if any other bytes non zero we pad:
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* otherwise we don't.
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*/
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for (i = 1; i < a->length; i++) if (a->data[i]) {
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pad = 1;
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pb = 0xFF;
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break;
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}
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}
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}
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ret += pad;
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}
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if (pp == NULL)
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return (ret);
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p= *pp;
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if (pad)
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*(p++) = pb;
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if (a->length == 0)
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*(p++) = 0;
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else if (!neg)
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memcpy(p, a->data, a->length);
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else {
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/* Begin at the end of the encoding */
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n = a->data + a->length - 1;
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p += a->length - 1;
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i = a->length;
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/* Copy zeros to destination as long as source is zero */
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while (!*n) {
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*(p--) = 0;
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n--;
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i--;
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}
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/* Complement and increment next octet */
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*(p--) = ((*(n--)) ^ 0xff) + 1;
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i--;
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/* Complement any octets left */
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for (; i > 0; i--)
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*(p--) = *(n--) ^ 0xff;
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}
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*pp += ret;
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return (ret);
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}
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/* Convert just ASN1 INTEGER content octets to ASN1_INTEGER structure */
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ASN1_INTEGER *
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c2i_ASN1_INTEGER(ASN1_INTEGER **a, const unsigned char **pp, long len)
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{
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ASN1_INTEGER *ret = NULL;
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const unsigned char *p, *pend;
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unsigned char *to, *s;
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int i;
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if ((a == NULL) || ((*a) == NULL)) {
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if ((ret = ASN1_INTEGER_new()) == NULL)
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return (NULL);
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} else
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ret = (*a);
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if (!ASN1_INTEGER_valid(ret)) {
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/*
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* XXX using i for an alert is confusing,
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* we should call this al
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*/
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i = ERR_R_ASN1_LENGTH_MISMATCH;
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goto err;
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}
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p = *pp;
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pend = p + len;
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/* We must malloc stuff, even for 0 bytes otherwise it
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* signifies a missing NULL parameter. */
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if (len < 0 || len > INT_MAX) {
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i = ERR_R_ASN1_LENGTH_MISMATCH;
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goto err;
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}
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s = malloc(len + 1);
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if (s == NULL) {
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i = ERR_R_MALLOC_FAILURE;
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goto err;
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}
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to = s;
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if (!len) {
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/* Strictly speaking this is an illegal INTEGER but we
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* tolerate it.
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*/
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ret->type = V_ASN1_INTEGER;
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} else if (*p & 0x80) /* a negative number */ {
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ret->type = V_ASN1_NEG_INTEGER;
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if ((*p == 0xff) && (len != 1)) {
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p++;
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len--;
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}
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i = len;
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p += i - 1;
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to += i - 1;
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while((!*p) && i) {
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*(to--) = 0;
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i--;
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p--;
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}
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/* Special case: if all zeros then the number will be of
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* the form FF followed by n zero bytes: this corresponds to
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* 1 followed by n zero bytes. We've already written n zeros
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* so we just append an extra one and set the first byte to
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* a 1. This is treated separately because it is the only case
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* where the number of bytes is larger than len.
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*/
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if (!i) {
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*s = 1;
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s[len] = 0;
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len++;
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} else {
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*(to--) = (*(p--) ^ 0xff) + 1;
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i--;
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for (; i > 0; i--)
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*(to--) = *(p--) ^ 0xff;
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}
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} else {
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ret->type = V_ASN1_INTEGER;
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if ((*p == 0) && (len != 1)) {
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p++;
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len--;
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}
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memcpy(s, p, len);
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}
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free(ret->data);
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ret->data = s;
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ret->length = (int)len;
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if (a != NULL)
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(*a) = ret;
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*pp = pend;
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return (ret);
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err:
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ASN1error(i);
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if (a == NULL || *a != ret)
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ASN1_INTEGER_free(ret);
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return (NULL);
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}
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/* This is a version of d2i_ASN1_INTEGER that ignores the sign bit of
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* ASN1 integers: some broken software can encode a positive INTEGER
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* with its MSB set as negative (it doesn't add a padding zero).
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*/
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ASN1_INTEGER *
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d2i_ASN1_UINTEGER(ASN1_INTEGER **a, const unsigned char **pp, long length)
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{
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ASN1_INTEGER *ret = NULL;
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const unsigned char *p;
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unsigned char *s;
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long len;
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int inf, tag, xclass;
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int i;
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if ((a == NULL) || ((*a) == NULL)) {
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if ((ret = ASN1_INTEGER_new()) == NULL)
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return (NULL);
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} else
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ret = (*a);
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if (!ASN1_INTEGER_valid(ret)) {
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i = ERR_R_ASN1_LENGTH_MISMATCH;
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goto err;
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}
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p = *pp;
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inf = ASN1_get_object(&p, &len, &tag, &xclass, length);
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if (inf & 0x80) {
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i = ASN1_R_BAD_OBJECT_HEADER;
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goto err;
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}
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if (tag != V_ASN1_INTEGER) {
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i = ASN1_R_EXPECTING_AN_INTEGER;
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goto err;
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}
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/* We must malloc stuff, even for 0 bytes otherwise it
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* signifies a missing NULL parameter. */
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if (len < 0 || len > INT_MAX) {
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i = ERR_R_ASN1_LENGTH_MISMATCH;
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goto err;
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}
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s = malloc(len + 1);
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if (s == NULL) {
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i = ERR_R_MALLOC_FAILURE;
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goto err;
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}
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ret->type = V_ASN1_INTEGER;
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if (len) {
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if ((*p == 0) && (len != 1)) {
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p++;
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len--;
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}
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memcpy(s, p, len);
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p += len;
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}
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free(ret->data);
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ret->data = s;
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ret->length = (int)len;
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if (a != NULL)
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(*a) = ret;
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*pp = p;
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return (ret);
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err:
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ASN1error(i);
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if (a == NULL || *a != ret)
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ASN1_INTEGER_free(ret);
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return (NULL);
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}
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int
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ASN1_INTEGER_set(ASN1_INTEGER *a, long v)
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{
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int j, k;
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unsigned int i;
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unsigned char buf[sizeof(long) + 1];
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long d;
|
||
|
|
|
||
|
|
a->type = V_ASN1_INTEGER;
|
||
|
|
/* XXX ssl/ssl_asn1.c:i2d_SSL_SESSION() depends upon this bound vae */
|
||
|
|
if (a->length < (int)(sizeof(long) + 1)) {
|
||
|
|
free(a->data);
|
||
|
|
a->data = calloc(1, sizeof(long) + 1);
|
||
|
|
}
|
||
|
|
if (a->data == NULL) {
|
||
|
|
ASN1error(ERR_R_MALLOC_FAILURE);
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
d = v;
|
||
|
|
if (d < 0) {
|
||
|
|
d = -d;
|
||
|
|
a->type = V_ASN1_NEG_INTEGER;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (i = 0; i < sizeof(long); i++) {
|
||
|
|
if (d == 0)
|
||
|
|
break;
|
||
|
|
buf[i] = (int)d & 0xff;
|
||
|
|
d >>= 8;
|
||
|
|
}
|
||
|
|
j = 0;
|
||
|
|
for (k = i - 1; k >= 0; k--)
|
||
|
|
a->data[j++] = buf[k];
|
||
|
|
a->length = j;
|
||
|
|
return (1);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* XXX this particular API is a gibbering eidrich horror that makes it
|
||
|
|
* impossible to determine valid return cases from errors.. "a bit
|
||
|
|
* ugly" is preserved for posterity, unfortunately this is probably
|
||
|
|
* unfixable without changing public API
|
||
|
|
*/
|
||
|
|
long
|
||
|
|
ASN1_INTEGER_get(const ASN1_INTEGER *a)
|
||
|
|
{
|
||
|
|
int neg = 0, i;
|
||
|
|
unsigned long r = 0;
|
||
|
|
|
||
|
|
if (a == NULL)
|
||
|
|
return (0L);
|
||
|
|
i = a->type;
|
||
|
|
if (i == V_ASN1_NEG_INTEGER)
|
||
|
|
neg = 1;
|
||
|
|
else if (i != V_ASN1_INTEGER)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
if (!ASN1_INTEGER_valid(a))
|
||
|
|
return -1; /* XXX best effort */
|
||
|
|
|
||
|
|
if (a->length > (int)sizeof(long)) {
|
||
|
|
/* hmm... a bit ugly, return all ones */
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
if (a->data == NULL)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
for (i = 0; i < a->length; i++) {
|
||
|
|
r <<= 8;
|
||
|
|
r |= (unsigned char)a->data[i];
|
||
|
|
}
|
||
|
|
|
||
|
|
if (r > LONG_MAX)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
if (neg)
|
||
|
|
return -(long)r;
|
||
|
|
return (long)r;
|
||
|
|
}
|
||
|
|
|
||
|
|
ASN1_INTEGER *
|
||
|
|
BN_to_ASN1_INTEGER(const BIGNUM *bn, ASN1_INTEGER *ai)
|
||
|
|
{
|
||
|
|
ASN1_INTEGER *ret;
|
||
|
|
int len, j;
|
||
|
|
|
||
|
|
if (ai == NULL)
|
||
|
|
ret = ASN1_INTEGER_new();
|
||
|
|
else
|
||
|
|
ret = ai;
|
||
|
|
if (ret == NULL) {
|
||
|
|
ASN1error(ERR_R_NESTED_ASN1_ERROR);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!ASN1_INTEGER_valid(ret))
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
if (BN_is_negative(bn))
|
||
|
|
ret->type = V_ASN1_NEG_INTEGER;
|
||
|
|
else
|
||
|
|
ret->type = V_ASN1_INTEGER;
|
||
|
|
j = BN_num_bits(bn);
|
||
|
|
len = ((j == 0) ? 0 : ((j / 8) + 1));
|
||
|
|
if (ret->length < len + 4) {
|
||
|
|
unsigned char *new_data = realloc(ret->data, len + 4);
|
||
|
|
if (!new_data) {
|
||
|
|
ASN1error(ERR_R_MALLOC_FAILURE);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
ret->data = new_data;
|
||
|
|
}
|
||
|
|
ret->length = BN_bn2bin(bn, ret->data);
|
||
|
|
|
||
|
|
/* Correct zero case */
|
||
|
|
if (!ret->length) {
|
||
|
|
ret->data[0] = 0;
|
||
|
|
ret->length = 1;
|
||
|
|
}
|
||
|
|
return (ret);
|
||
|
|
|
||
|
|
err:
|
||
|
|
if (ret != ai)
|
||
|
|
ASN1_INTEGER_free(ret);
|
||
|
|
return (NULL);
|
||
|
|
}
|
||
|
|
|
||
|
|
BIGNUM *
|
||
|
|
ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn)
|
||
|
|
{
|
||
|
|
BIGNUM *ret;
|
||
|
|
|
||
|
|
if (!ASN1_INTEGER_valid(ai))
|
||
|
|
return (NULL);
|
||
|
|
|
||
|
|
if ((ret = BN_bin2bn(ai->data, ai->length, bn)) == NULL)
|
||
|
|
ASN1error(ASN1_R_BN_LIB);
|
||
|
|
else if (ai->type == V_ASN1_NEG_INTEGER)
|
||
|
|
BN_set_negative(ret, 1);
|
||
|
|
return (ret);
|
||
|
|
}
|