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|
/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (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>
#include <limits.h>
#include "internal/cryptlib.h"
#include <openssl/asn1.h>
#include "asn1_locl.h"
static int asn1_get_length(const unsigned char **pp, int *inf, long *rl,
long max);
static void asn1_put_length(unsigned char **pp, int length);
static int _asn1_check_infinite_end(const unsigned char **p, long len)
{
/*
* If there is 0 or 1 byte left, the length check should pick things up
*/
if (len <= 0)
return 1;
else if ((len >= 2) && ((*p)[0] == 0) && ((*p)[1] == 0)) {
(*p) += 2;
return 1;
}
return 0;
}
int ASN1_check_infinite_end(unsigned char **p, long len)
{
return _asn1_check_infinite_end((const unsigned char **)p, len);
}
int ASN1_const_check_infinite_end(const unsigned char **p, long len)
{
return _asn1_check_infinite_end(p, len);
}
int ASN1_get_object(const unsigned char **pp, long *plength, int *ptag,
int *pclass, long omax)
{
int i, ret;
long l;
const unsigned char *p = *pp;
int tag, xclass, inf;
long max = omax;
if (!max)
goto err;
ret = (*p & V_ASN1_CONSTRUCTED);
xclass = (*p & V_ASN1_PRIVATE);
i = *p & V_ASN1_PRIMITIVE_TAG;
if (i == V_ASN1_PRIMITIVE_TAG) { /* high-tag */
p++;
if (--max == 0)
goto err;
l = 0;
while (*p & 0x80) {
l <<= 7L;
l |= *(p++) & 0x7f;
if (--max == 0)
goto err;
if (l > (INT_MAX >> 7L))
goto err;
}
l <<= 7L;
l |= *(p++) & 0x7f;
tag = (int)l;
if (--max == 0)
goto err;
} else {
tag = i;
p++;
if (--max == 0)
goto err;
}
*ptag = tag;
*pclass = xclass;
if (!asn1_get_length(&p, &inf, plength, max))
goto err;
if (inf && !(ret & V_ASN1_CONSTRUCTED))
goto err;
if (*plength > (omax - (p - *pp))) {
ASN1err(ASN1_F_ASN1_GET_OBJECT, ASN1_R_TOO_LONG);
/*
* Set this so that even if things are not long enough the values are
* set correctly
*/
ret |= 0x80;
}
*pp = p;
return ret | inf;
err:
ASN1err(ASN1_F_ASN1_GET_OBJECT, ASN1_R_HEADER_TOO_LONG);
return 0x80;
}
/*
* Decode a length field.
* The short form is a single byte defining a length 0 - 127.
* The long form is a byte 0 - 127 with the top bit set and this indicates
* the number of following octets that contain the length. These octets
* are stored most significant digit first.
*/
static int asn1_get_length(const unsigned char **pp, int *inf, long *rl,
long max)
{
const unsigned char *p = *pp;
unsigned long ret = 0;
int i;
if (max-- < 1)
return 0;
if (*p == 0x80) {
*inf = 1;
p++;
} else {
*inf = 0;
i = *p & 0x7f;
if (*p++ & 0x80) {
if (max < i + 1)
return 0;
/* Skip leading zeroes */
while (i > 0 && *p == 0) {
p++;
i--;
}
if (i > (int)sizeof(long))
return 0;
while (i > 0) {
ret <<= 8;
ret |= *p++;
i--;
}
if (ret > LONG_MAX)
return 0;
} else
ret = i;
}
*pp = p;
*rl = (long)ret;
return 1;
}
/*
* class 0 is constructed constructed == 2 for indefinite length constructed
*/
void ASN1_put_object(unsigned char **pp, int constructed, int length, int tag,
int xclass)
{
unsigned char *p = *pp;
int i, ttag;
i = (constructed) ? V_ASN1_CONSTRUCTED : 0;
i |= (xclass & V_ASN1_PRIVATE);
if (tag < 31)
*(p++) = i | (tag & V_ASN1_PRIMITIVE_TAG);
else {
*(p++) = i | V_ASN1_PRIMITIVE_TAG;
for (i = 0, ttag = tag; ttag > 0; i++)
ttag >>= 7;
ttag = i;
while (i-- > 0) {
p[i] = tag & 0x7f;
if (i != (ttag - 1))
p[i] |= 0x80;
tag >>= 7;
}
p += ttag;
}
if (constructed == 2)
*(p++) = 0x80;
else
asn1_put_length(&p, length);
*pp = p;
}
int ASN1_put_eoc(unsigned char **pp)
{
unsigned char *p = *pp;
*p++ = 0;
*p++ = 0;
*pp = p;
return 2;
}
static void asn1_put_length(unsigned char **pp, int length)
{
unsigned char *p = *pp;
int i, l;
if (length <= 127)
*(p++) = (unsigned char)length;
else {
l = length;
for (i = 0; l > 0; i++)
l >>= 8;
*(p++) = i | 0x80;
l = i;
while (i-- > 0) {
p[i] = length & 0xff;
length >>= 8;
}
p += l;
}
*pp = p;
}
int ASN1_object_size(int constructed, int length, int
|