ref: 009439541d2c6e8af2596f8fb1b4df85861fd212
dir: /third_party/boringssl/src/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.
*
* 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 <assert.h>
#include <limits.h>
#include <string.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include "../internal.h"
ASN1_INTEGER *ASN1_INTEGER_dup(const ASN1_INTEGER *x) {
return ASN1_STRING_dup(x);
}
int ASN1_INTEGER_cmp(const ASN1_INTEGER *x, const ASN1_INTEGER *y) {
// Compare signs.
int neg = x->type & V_ASN1_NEG;
if (neg != (y->type & V_ASN1_NEG)) {
return neg ? -1 : 1;
}
int ret = ASN1_STRING_cmp(x, y);
if (neg) {
// This could be |-ret|, but |ASN1_STRING_cmp| is not forbidden from
// returning |INT_MIN|.
if (ret < 0) {
return 1;
} else if (ret > 0) {
return -1;
} else {
return 0;
}
}
return ret;
}
// negate_twos_complement negates |len| bytes from |buf| in-place, interpreted
// as a signed, big-endian two's complement value.
static void negate_twos_complement(uint8_t *buf, size_t len) {
uint8_t borrow = 0;
for (size_t i = len - 1; i < len; i--) {
uint8_t t = buf[i];
buf[i] = 0u - borrow - t;
borrow |= t != 0;
}
}
static int is_all_zeros(const uint8_t *in, size_t len) {
for (size_t i = 0; i < len; i++) {
if (in[i] != 0) {
return 0;
}
}
return 1;
}
int i2c_ASN1_INTEGER(const ASN1_INTEGER *in, unsigned char **outp) {
if (in == NULL) {
return 0;
}
// |ASN1_INTEGER|s should be represented minimally, but it is possible to
// construct invalid ones. Skip leading zeros so this does not produce an
// invalid encoding or break invariants.
CBS cbs;
CBS_init(&cbs, in->data, in->length);
while (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0) {
CBS_skip(&cbs, 1);
}
int is_negative = (in->type & V_ASN1_NEG) != 0;
size_t pad;
CBS copy = cbs;
uint8_t msb;
if (!CBS_get_u8(©, &msb)) {
// Zero is represented as a single byte.
is_negative = 0;
pad = 1;
} else if (is_negative) {
// 0x80...01 through 0xff...ff have a two's complement of 0x7f...ff
// through 0x00...01 and need an extra byte to be negative.
// 0x01...00 through 0x80...00 have a two's complement of 0xfe...ff
// through 0x80...00 and can be negated as-is.
pad = msb > 0x80 ||
(msb == 0x80 && !is_all_zeros(CBS_data(©), CBS_len(©)));
} else {
// If the high bit is set, the signed representation needs an extra
// byte to be positive.
pad = (msb & 0x80) != 0;
}
if (CBS_len(&cbs) > INT_MAX - pad) {
OPENSSL_PUT_ERROR(ASN1, ERR_R_OVERFLOW);
return 0;
}
int len = (int)(pad + CBS_len(&cbs));
assert(len > 0);
if (outp == NULL) {
return len;
}
if (pad) {
(*outp)[0] = 0;
}
OPENSSL_memcpy(*outp + pad, CBS_data(&cbs), CBS_len(&cbs));
if (is_negative) {
negate_twos_complement(*outp, len);
assert((*outp)[0] >= 0x80);
} else {
assert((*outp)[0] < 0x80);
}
*outp += len;
return len;
}
ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **out, const unsigned char **inp,
long len) {
// This function can handle lengths up to INT_MAX - 1, but the rest of the
// legacy ASN.1 code mixes integer types, so avoid exposing it to
// ASN1_INTEGERS with larger lengths.
if (len < 0 || len > INT_MAX / 2) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_TOO_LONG);
return NULL;
}
CBS cbs;
CBS_init(&cbs, *inp, (size_t)len);
int is_negative;
if (!CBS_is_valid_asn1_integer(&cbs, &is_negative)) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER);
return NULL;
}
ASN1_INTEGER *ret = NULL;
if (out == NULL || *out == NULL) {
ret = ASN1_INTEGER_new();
if (ret == NULL) {
return NULL;
}
} else {
ret = *out;
}
// Convert to |ASN1_INTEGER|'s sign-and-magnitude representation. First,
// determine the size needed for a minimal result.
if (is_negative) {
// 0xff00...01 through 0xff7f..ff have a two's complement of 0x00ff...ff
// through 0x000100...001 and need one leading zero removed. 0x8000...00
// through 0xff00...00 have a two's complement of 0x8000...00 through
// 0x0100...00 and will be minimally-encoded as-is.
if (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0xff &&
!is_all_zeros(CBS_data(&cbs) + 1, CBS_len(&cbs) - 1)) {
CBS_skip(&cbs, 1);
}
} else {
// Remove the leading zero byte, if any.
if (CBS_len(&cbs) > 0 && CBS_data(&cbs)[0] == 0x00) {
CBS_skip(&cbs, 1);
}
}
if (!ASN1_STRING_set(ret, CBS_data(&cbs), CBS_len(&cbs))) {
goto err;
}
if (is_negative) {
ret->type = V_ASN1_NEG_INTEGER;
negate_twos_complement(ret->data, ret->length);
} else {
ret->type = V_ASN1_INTEGER;
}
// The value should be minimally-encoded.
assert(ret->length == 0 || ret->data[0] != 0);
// Zero is not negative.
assert(!is_negative || ret->length > 0);
*inp += len;
if (out != NULL) {
*out = ret;
}
return ret;
err:
if (ret != NULL && (out == NULL || *out != ret)) {
ASN1_INTEGER_free(ret);
}
return NULL;
}
int ASN1_INTEGER_set_int64(ASN1_INTEGER *a, int64_t v) {
if (v >= 0) {
return ASN1_INTEGER_set_uint64(a, (uint64_t)v);
}
if (!ASN1_INTEGER_set_uint64(a, 0 - (uint64_t)v)) {
return 0;
}
a->type = V_ASN1_NEG_INTEGER;
return 1;
}
int ASN1_ENUMERATED_set_int64(ASN1_ENUMERATED *a, int64_t v) {
if (v >= 0) {
return ASN1_ENUMERATED_set_uint64(a, (uint64_t)v);
}
if (!ASN1_ENUMERATED_set_uint64(a, 0 - (uint64_t)v)) {
return 0;
}
a->type = V_ASN1_NEG_ENUMERATED;
return 1;
}
int ASN1_INTEGER_set(ASN1_INTEGER *a, long v) {
static_assert(sizeof(long) <= sizeof(int64_t), "long fits in int64_t");
return ASN1_INTEGER_set_int64(a, v);
}
int ASN1_ENUMERATED_set(ASN1_ENUMERATED *a, long v) {
static_assert(sizeof(long) <= sizeof(int64_t), "long fits in int64_t");
return ASN1_ENUMERATED_set_int64(a, v);
}
static int asn1_string_set_uint64(ASN1_STRING *out, uint64_t v, int type) {
uint8_t buf[sizeof(uint64_t)];
CRYPTO_store_u64_be(buf, v);
size_t leading_zeros;
for (leading_zeros = 0; leading_zeros < sizeof(buf); leading_zeros++) {
if (buf[leading_zeros] != 0) {
break;
}
}
if (!ASN1_STRING_set(out, buf + leading_zeros, sizeof(buf) - leading_zeros)) {
return 0;
}
out->type = type;
return 1;
}
int ASN1_INTEGER_set_uint64(ASN1_INTEGER *out, uint64_t v) {
return asn1_string_set_uint64(out, v, V_ASN1_INTEGER);
}
int ASN1_ENUMERATED_set_uint64(ASN1_ENUMERATED *out, uint64_t v) {
return asn1_string_set_uint64(out, v, V_ASN1_ENUMERATED);
}
static int asn1_string_get_abs_uint64(uint64_t *out, const ASN1_STRING *a,
int type) {
if ((a->type & ~V_ASN1_NEG) != type) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_INTEGER_TYPE);
return 0;
}
uint8_t buf[sizeof(uint64_t)] = {0};
if (a->length > (int)sizeof(buf)) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER);
return 0;
}
OPENSSL_memcpy(buf + sizeof(buf) - a->length, a->data, a->length);
*out = CRYPTO_load_u64_be(buf);
return 1;
}
static int asn1_string_get_uint64(uint64_t *out, const ASN1_STRING *a,
int type) {
if (!asn1_string_get_abs_uint64(out, a, type)) {
return 0;
}
if (a->type & V_ASN1_NEG) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER);
return 0;
}
return 1;
}
int ASN1_INTEGER_get_uint64(uint64_t *out, const ASN1_INTEGER *a) {
return asn1_string_get_uint64(out, a, V_ASN1_INTEGER);
}
int ASN1_ENUMERATED_get_uint64(uint64_t *out, const ASN1_ENUMERATED *a) {
return asn1_string_get_uint64(out, a, V_ASN1_ENUMERATED);
}
static int asn1_string_get_int64(int64_t *out, const ASN1_STRING *a, int type) {
uint64_t v;
if (!asn1_string_get_abs_uint64(&v, a, type)) {
return 0;
}
int64_t i64;
int fits_in_i64;
// Check |v != 0| to handle manually-constructed negative zeros.
if ((a->type & V_ASN1_NEG) && v != 0) {
i64 = (int64_t)(0u - v);
fits_in_i64 = i64 < 0;
} else {
i64 = (int64_t)v;
fits_in_i64 = i64 >= 0;
}
if (!fits_in_i64) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_INTEGER);
return 0;
}
*out = i64;
return 1;
}
int ASN1_INTEGER_get_int64(int64_t *out, const ASN1_INTEGER *a) {
return asn1_string_get_int64(out, a, V_ASN1_INTEGER);
}
int ASN1_ENUMERATED_get_int64(int64_t *out, const ASN1_ENUMERATED *a) {
return asn1_string_get_int64(out, a, V_ASN1_ENUMERATED);
}
static long asn1_string_get_long(const ASN1_STRING *a, int type) {
if (a == NULL) {
return 0;
}
int64_t v;
if (!asn1_string_get_int64(&v, a, type) || //
v < LONG_MIN || v > LONG_MAX) {
// This function's return value does not distinguish overflow from -1.
ERR_clear_error();
return -1;
}
return (long)v;
}
long ASN1_INTEGER_get(const ASN1_INTEGER *a) {
return asn1_string_get_long(a, V_ASN1_INTEGER);
}
long ASN1_ENUMERATED_get(const ASN1_ENUMERATED *a) {
return asn1_string_get_long(a, V_ASN1_ENUMERATED);
}
static ASN1_STRING *bn_to_asn1_string(const BIGNUM *bn, ASN1_STRING *ai,
int type) {
ASN1_INTEGER *ret;
if (ai == NULL) {
ret = ASN1_STRING_type_new(type);
} else {
ret = ai;
}
if (ret == NULL) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
goto err;
}
if (BN_is_negative(bn) && !BN_is_zero(bn)) {
ret->type = type | V_ASN1_NEG;
} else {
ret->type = type;
}
int len = BN_num_bytes(bn);
if (!ASN1_STRING_set(ret, NULL, len) ||
!BN_bn2bin_padded(ret->data, len, bn)) {
goto err;
}
return ret;
err:
if (ret != ai) {
ASN1_STRING_free(ret);
}
return NULL;
}
ASN1_INTEGER *BN_to_ASN1_INTEGER(const BIGNUM *bn, ASN1_INTEGER *ai) {
return bn_to_asn1_string(bn, ai, V_ASN1_INTEGER);
}
ASN1_ENUMERATED *BN_to_ASN1_ENUMERATED(const BIGNUM *bn, ASN1_ENUMERATED *ai) {
return bn_to_asn1_string(bn, ai, V_ASN1_ENUMERATED);
}
static BIGNUM *asn1_string_to_bn(const ASN1_STRING *ai, BIGNUM *bn, int type) {
if ((ai->type & ~V_ASN1_NEG) != type) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_INTEGER_TYPE);
return NULL;
}
BIGNUM *ret;
if ((ret = BN_bin2bn(ai->data, ai->length, bn)) == NULL) {
OPENSSL_PUT_ERROR(ASN1, ASN1_R_BN_LIB);
} else if (ai->type & V_ASN1_NEG) {
BN_set_negative(ret, 1);
}
return ret;
}
BIGNUM *ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn) {
return asn1_string_to_bn(ai, bn, V_ASN1_INTEGER);
}
BIGNUM *ASN1_ENUMERATED_to_BN(const ASN1_ENUMERATED *ai, BIGNUM *bn) {
return asn1_string_to_bn(ai, bn, V_ASN1_ENUMERATED);
}