pineapple/externals/libressl/crypto/asn1/a_int.c

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2020-12-28 16:15:37 +01:00
/* $OpenBSD: a_int.c,v 1.34 2019/04/28 05:03:56 tb Exp $ */
/* 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 <limits.h>
#include <stdio.h>
#include <string.h>
#include <openssl/asn1.h>
#include <openssl/bn.h>
#include <openssl/err.h>
static int
ASN1_INTEGER_valid(const ASN1_INTEGER *a)
{
return (a != NULL && a->length >= 0);
}
ASN1_INTEGER *
ASN1_INTEGER_dup(const ASN1_INTEGER *x)
{
if (!ASN1_INTEGER_valid(x))
return NULL;
return ASN1_STRING_dup(x);
}
int
ASN1_INTEGER_cmp(const ASN1_INTEGER *x, const ASN1_INTEGER *y)
{
int neg, ret;
/* Compare signs */
neg = x->type & V_ASN1_NEG;
if (neg != (y->type & V_ASN1_NEG)) {
if (neg)
return -1;
else
return 1;
}
ret = ASN1_STRING_cmp(x, y);
if (neg)
return -ret;
else
return ret;
}
/*
* This converts an ASN1 INTEGER into its content encoding.
* The internal representation is an ASN1_STRING whose data is a big endian
* representation of the value, ignoring the sign. The sign is determined by
* the type: V_ASN1_INTEGER for positive and V_ASN1_NEG_INTEGER for negative.
*
* Positive integers are no problem: they are almost the same as the DER
* encoding, except if the first byte is >= 0x80 we need to add a zero pad.
*
* Negative integers are a bit trickier...
* The DER representation of negative integers is in 2s complement form.
* The internal form is converted by complementing each octet and finally
* adding one to the result. This can be done less messily with a little trick.
* If the internal form has trailing zeroes then they will become FF by the
* complement and 0 by the add one (due to carry) so just copy as many trailing
* zeros to the destination as there are in the source. The carry will add one
* to the last none zero octet: so complement this octet and add one and finally
* complement any left over until you get to the start of the string.
*
* Padding is a little trickier too. If the first bytes is > 0x80 then we pad
* with 0xff. However if the first byte is 0x80 and one of the following bytes
* is non-zero we pad with 0xff. The reason for this distinction is that 0x80
* followed by optional zeros isn't padded.
*/
int
i2c_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp)
{
int pad = 0, ret, i, neg;
unsigned char *p, *n, pb = 0;
if (!ASN1_INTEGER_valid(a))
return 0;
neg = a->type & V_ASN1_NEG;
if (a->length == 0)
ret = 1;
else {
ret = a->length;
i = a->data[0];
if (!neg && (i > 127)) {
pad = 1;
pb = 0;
} else if (neg) {
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.
*/
for (i = 1; i < a->length; i++) if (a->data[i]) {
pad = 1;
pb = 0xFF;
break;
}
}
}
ret += pad;
}
if (pp == NULL)
return (ret);
p= *pp;
if (pad)
*(p++) = pb;
if (a->length == 0)
*(p++) = 0;
else if (!neg)
memcpy(p, a->data, a->length);
else {
/* Begin at the end of the encoding */
n = a->data + a->length - 1;
p += a->length - 1;
i = a->length;
/* Copy zeros to destination as long as source is zero */
while (!*n) {
*(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;
}
*pp += ret;
return (ret);
}
/* Convert just ASN1 INTEGER content octets to ASN1_INTEGER structure */
ASN1_INTEGER *
c2i_ASN1_INTEGER(ASN1_INTEGER **a, const unsigned char **pp, long len)
{
ASN1_INTEGER *ret = NULL;
const unsigned char *p, *pend;
unsigned char *to, *s;
int i;
if ((a == NULL) || ((*a) == NULL)) {
if ((ret = ASN1_INTEGER_new()) == NULL)
return (NULL);
} else
ret = (*a);
if (!ASN1_INTEGER_valid(ret)) {
/*
* XXX using i for an alert is confusing,
* we should call this al
*/
i = ERR_R_ASN1_LENGTH_MISMATCH;
goto err;
}
p = *pp;
pend = p + len;
/* We must malloc stuff, even for 0 bytes otherwise it
* signifies a missing NULL parameter. */
if (len < 0 || len > INT_MAX) {
i = ERR_R_ASN1_LENGTH_MISMATCH;
goto err;
}
s = malloc(len + 1);
if (s == NULL) {
i = ERR_R_MALLOC_FAILURE;
goto err;
}
to = s;
if (!len) {
/* Strictly speaking this is an illegal INTEGER but we
* tolerate it.
*/
ret->type = V_ASN1_INTEGER;
} else if (*p & 0x80) /* a negative number */ {
ret->type = V_ASN1_NEG_INTEGER;
if ((*p == 0xff) && (len != 1)) {
p++;
len--;
}
i = len;
p += i - 1;
to += i - 1;
while((!*p) && i) {
*(to--) = 0;
i--;
p--;
}
/* Special case: if all zeros then the number will be of
* the form FF followed by n zero bytes: this corresponds to
* 1 followed by n zero bytes. We've already written n zeros
* so we just append an extra one and set the first byte to
* a 1. This is treated separately because it is the only case
* where the number of bytes is larger than len.
*/
if (!i) {
*s = 1;
s[len] = 0;
len++;
} else {
*(to--) = (*(p--) ^ 0xff) + 1;
i--;
for (; i > 0; i--)
*(to--) = *(p--) ^ 0xff;
}
} else {
ret->type = V_ASN1_INTEGER;
if ((*p == 0) && (len != 1)) {
p++;
len--;
}
memcpy(s, p, len);
}
free(ret->data);
ret->data = s;
ret->length = (int)len;
if (a != NULL)
(*a) = ret;
*pp = pend;
return (ret);
err:
ASN1error(i);
if (a == NULL || *a != ret)
ASN1_INTEGER_free(ret);
return (NULL);
}
/* This is a version of d2i_ASN1_INTEGER that ignores the sign bit of
* ASN1 integers: some broken software can encode a positive INTEGER
* with its MSB set as negative (it doesn't add a padding zero).
*/
ASN1_INTEGER *
d2i_ASN1_UINTEGER(ASN1_INTEGER **a, const unsigned char **pp, long length)
{
ASN1_INTEGER *ret = NULL;
const unsigned char *p;
unsigned char *s;
long len;
int inf, tag, xclass;
int i;
if ((a == NULL) || ((*a) == NULL)) {
if ((ret = ASN1_INTEGER_new()) == NULL)
return (NULL);
} else
ret = (*a);
if (!ASN1_INTEGER_valid(ret)) {
i = ERR_R_ASN1_LENGTH_MISMATCH;
goto err;
}
p = *pp;
inf = ASN1_get_object(&p, &len, &tag, &xclass, length);
if (inf & 0x80) {
i = ASN1_R_BAD_OBJECT_HEADER;
goto err;
}
if (tag != V_ASN1_INTEGER) {
i = ASN1_R_EXPECTING_AN_INTEGER;
goto err;
}
/* We must malloc stuff, even for 0 bytes otherwise it
* signifies a missing NULL parameter. */
if (len < 0 || len > INT_MAX) {
i = ERR_R_ASN1_LENGTH_MISMATCH;
goto err;
}
s = malloc(len + 1);
if (s == NULL) {
i = ERR_R_MALLOC_FAILURE;
goto err;
}
ret->type = V_ASN1_INTEGER;
if (len) {
if ((*p == 0) && (len != 1)) {
p++;
len--;
}
memcpy(s, p, len);
p += len;
}
free(ret->data);
ret->data = s;
ret->length = (int)len;
if (a != NULL)
(*a) = ret;
*pp = p;
return (ret);
err:
ASN1error(i);
if (a == NULL || *a != ret)
ASN1_INTEGER_free(ret);
return (NULL);
}
int
ASN1_INTEGER_set(ASN1_INTEGER *a, long v)
{
int j, k;
unsigned int i;
unsigned char buf[sizeof(long) + 1];
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);
}