ref: 8bc69a872883224675a55db51ac8f60ab5ed9e5a
dir: /third_party/boringssl/src/crypto/asn1/a_bitstr.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 <openssl/asn1.h>
#include <limits.h>
#include <string.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include "../internal.h"
#include "internal.h"
int ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, const unsigned char *d, int len)
{
return ASN1_STRING_set(x, d, len);
}
int asn1_bit_string_length(const ASN1_BIT_STRING *str,
uint8_t *out_padding_bits) {
int len = str->length;
if (str->flags & ASN1_STRING_FLAG_BITS_LEFT) {
// If the string is already empty, it cannot have padding bits.
*out_padding_bits = len == 0 ? 0 : str->flags & 0x07;
return len;
}
// TODO(https://crbug.com/boringssl/447): If we move this logic to
// |ASN1_BIT_STRING_set_bit|, can we remove this representation?
while (len > 0 && str->data[len - 1] == 0) {
len--;
}
uint8_t padding_bits = 0;
if (len > 0) {
uint8_t last = str->data[len - 1];
assert(last != 0);
for (; padding_bits < 7; padding_bits++) {
if (last & (1 << padding_bits)) {
break;
}
}
}
*out_padding_bits = padding_bits;
return len;
}
int ASN1_BIT_STRING_num_bytes(const ASN1_BIT_STRING *str, size_t *out) {
uint8_t padding_bits;
int len = asn1_bit_string_length(str, &padding_bits);
if (padding_bits != 0) {
return 0;
}
*out = len;
return 1;
}
int i2c_ASN1_BIT_STRING(const ASN1_BIT_STRING *a, unsigned char **pp)
{
if (a == NULL) {
return 0;
}
uint8_t bits;
int len = asn1_bit_string_length(a, &bits);
int ret = 1 + len;
if (pp == NULL) {
return ret;
}
uint8_t *p = *pp;
*(p++) = bits;
OPENSSL_memcpy(p, a->data, len);
if (len > 0) {
p[len - 1] &= (0xff << bits);
}
p += len;
*pp = p;
return (ret);
}
ASN1_BIT_STRING *c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a,
const unsigned char **pp, long len)
{
ASN1_BIT_STRING *ret = NULL;
const unsigned char *p;
unsigned char *s;
int padding;
if (len < 1) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_STRING_TOO_SHORT);
goto err;
}
if (len > INT_MAX) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_STRING_TOO_LONG);
goto err;
}
if ((a == NULL) || ((*a) == NULL)) {
if ((ret = ASN1_BIT_STRING_new()) == NULL)
return (NULL);
} else
ret = (*a);
p = *pp;
padding = *(p++);
len--;
if (padding > 7) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_BIT_STRING_BITS_LEFT);
goto err;
}
/* Unused bits in a BIT STRING must be zero. */
uint8_t padding_mask = (1 << padding) - 1;
if (padding != 0 &&
(len < 1 || (p[len - 1] & padding_mask) != 0)) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_BIT_STRING_PADDING);
goto err;
}
/*
* We do this to preserve the settings. If we modify the settings, via
* the _set_bit function, we will recalculate on output
*/
ret->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear */
ret->flags |= (ASN1_STRING_FLAG_BITS_LEFT | padding); /* set */
if (len > 0) {
s = OPENSSL_memdup(p, len);
if (s == NULL) {
OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
goto err;
}
p += len;
} else {
s = NULL;
}
ret->length = (int)len;
OPENSSL_free(ret->data);
ret->data = s;
ret->type = V_ASN1_BIT_STRING;
if (a != NULL)
(*a) = ret;
*pp = p;
return (ret);
err:
if ((ret != NULL) && ((a == NULL) || (*a != ret)))
ASN1_BIT_STRING_free(ret);
return (NULL);
}
/*
* These next 2 functions from Goetz Babin-Ebell <babinebell@trustcenter.de>
*/
int ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)
{
int w, v, iv;
unsigned char *c;
w = n / 8;
v = 1 << (7 - (n & 0x07));
iv = ~v;
if (!value)
v = 0;
if (a == NULL)
return 0;
a->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); /* clear, set on write */
if ((a->length < (w + 1)) || (a->data == NULL)) {
if (!value)
return (1); /* Don't need to set */
if (a->data == NULL)
c = (unsigned char *)OPENSSL_malloc(w + 1);
else
c = (unsigned char *)OPENSSL_realloc(a->data, w + 1);
if (c == NULL) {
OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
return 0;
}
if (w + 1 - a->length > 0)
OPENSSL_memset(c + a->length, 0, w + 1 - a->length);
a->data = c;
a->length = w + 1;
}
a->data[w] = ((a->data[w]) & iv) | v;
while ((a->length > 0) && (a->data[a->length - 1] == 0))
a->length--;
return (1);
}
int ASN1_BIT_STRING_get_bit(const ASN1_BIT_STRING *a, int n)
{
int w, v;
w = n / 8;
v = 1 << (7 - (n & 0x07));
if ((a == NULL) || (a->length < (w + 1)) || (a->data == NULL))
return (0);
return ((a->data[w] & v) != 0);
}
/*
* Checks if the given bit string contains only bits specified by
* the flags vector. Returns 0 if there is at least one bit set in 'a'
* which is not specified in 'flags', 1 otherwise.
* 'len' is the length of 'flags'.
*/
int ASN1_BIT_STRING_check(const ASN1_BIT_STRING *a,
const unsigned char *flags, int flags_len)
{
int i, ok;
/* Check if there is one bit set at all. */
if (!a || !a->data)
return 1;
/*
* Check each byte of the internal representation of the bit string.
*/
ok = 1;
for (i = 0; i < a->length && ok; ++i) {
unsigned char mask = i < flags_len ? ~flags[i] : 0xff;
/* We are done if there is an unneeded bit set. */
ok = (a->data[i] & mask) == 0;
}
return ok;
}