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- /* 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/bn.h>
-
- #include <assert.h>
- #include <ctype.h>
- #include <limits.h>
- #include <stdio.h>
-
- #include <openssl/bio.h>
- #include <openssl/bytestring.h>
- #include <openssl/err.h>
- #include <openssl/mem.h>
-
- #include "../fipsmodule/bn/internal.h"
-
-
- int BN_bn2cbb_padded(CBB *out, size_t len, const BIGNUM *in) {
- uint8_t *ptr;
- return CBB_add_space(out, &ptr, len) && BN_bn2bin_padded(ptr, len, in);
- }
-
- static const char hextable[] = "0123456789abcdef";
-
- char *BN_bn2hex(const BIGNUM *bn) {
- char *buf = OPENSSL_malloc(1 /* leading '-' */ + 1 /* zero is non-empty */ +
- bn->top * BN_BYTES * 2 + 1 /* trailing NUL */);
- if (buf == NULL) {
- OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE);
- return NULL;
- }
-
- char *p = buf;
- if (bn->neg) {
- *(p++) = '-';
- }
-
- if (BN_is_zero(bn)) {
- *(p++) = '0';
- }
-
- int z = 0;
- for (int i = bn->top - 1; i >= 0; i--) {
- for (int j = BN_BITS2 - 8; j >= 0; j -= 8) {
- // strip leading zeros
- int v = ((int)(bn->d[i] >> (long)j)) & 0xff;
- if (z || v != 0) {
- *(p++) = hextable[v >> 4];
- *(p++) = hextable[v & 0x0f];
- z = 1;
- }
- }
- }
- *p = '\0';
-
- return buf;
- }
-
- // decode_hex decodes |in_len| bytes of hex data from |in| and updates |bn|.
- static int decode_hex(BIGNUM *bn, const char *in, int in_len) {
- if (in_len > INT_MAX/4) {
- OPENSSL_PUT_ERROR(BN, BN_R_BIGNUM_TOO_LONG);
- return 0;
- }
- // |in_len| is the number of hex digits.
- if (!bn_expand(bn, in_len * 4)) {
- return 0;
- }
-
- int i = 0;
- while (in_len > 0) {
- // Decode one |BN_ULONG| at a time.
- int todo = BN_BYTES * 2;
- if (todo > in_len) {
- todo = in_len;
- }
-
- BN_ULONG word = 0;
- int j;
- for (j = todo; j > 0; j--) {
- char c = in[in_len - j];
-
- BN_ULONG hex;
- if (c >= '0' && c <= '9') {
- hex = c - '0';
- } else if (c >= 'a' && c <= 'f') {
- hex = c - 'a' + 10;
- } else if (c >= 'A' && c <= 'F') {
- hex = c - 'A' + 10;
- } else {
- hex = 0;
- // This shouldn't happen. The caller checks |isxdigit|.
- assert(0);
- }
- word = (word << 4) | hex;
- }
-
- bn->d[i++] = word;
- in_len -= todo;
- }
- assert(i <= bn->dmax);
- bn->top = i;
- return 1;
- }
-
- // decode_dec decodes |in_len| bytes of decimal data from |in| and updates |bn|.
- static int decode_dec(BIGNUM *bn, const char *in, int in_len) {
- int i, j;
- BN_ULONG l = 0;
-
- // Decode |BN_DEC_NUM| digits at a time.
- j = BN_DEC_NUM - (in_len % BN_DEC_NUM);
- if (j == BN_DEC_NUM) {
- j = 0;
- }
- l = 0;
- for (i = 0; i < in_len; i++) {
- l *= 10;
- l += in[i] - '0';
- if (++j == BN_DEC_NUM) {
- if (!BN_mul_word(bn, BN_DEC_CONV) ||
- !BN_add_word(bn, l)) {
- return 0;
- }
- l = 0;
- j = 0;
- }
- }
- return 1;
- }
-
- typedef int (*decode_func) (BIGNUM *bn, const char *in, int in_len);
- typedef int (*char_test_func) (int c);
-
- static int bn_x2bn(BIGNUM **outp, const char *in, decode_func decode, char_test_func want_char) {
- BIGNUM *ret = NULL;
- int neg = 0, i;
- int num;
-
- if (in == NULL || *in == 0) {
- return 0;
- }
-
- if (*in == '-') {
- neg = 1;
- in++;
- }
-
- for (i = 0; want_char((unsigned char)in[i]) && i + neg < INT_MAX; i++) {}
-
- num = i + neg;
- if (outp == NULL) {
- return num;
- }
-
- // in is the start of the hex digits, and it is 'i' long
- if (*outp == NULL) {
- ret = BN_new();
- if (ret == NULL) {
- return 0;
- }
- } else {
- ret = *outp;
- BN_zero(ret);
- }
-
- if (!decode(ret, in, i)) {
- goto err;
- }
-
- bn_correct_top(ret);
- if (!BN_is_zero(ret)) {
- ret->neg = neg;
- }
-
- *outp = ret;
- return num;
-
- err:
- if (*outp == NULL) {
- BN_free(ret);
- }
-
- return 0;
- }
-
- int BN_hex2bn(BIGNUM **outp, const char *in) {
- return bn_x2bn(outp, in, decode_hex, isxdigit);
- }
-
- char *BN_bn2dec(const BIGNUM *a) {
- // It is easier to print strings little-endian, so we assemble it in reverse
- // and fix at the end.
- BIGNUM *copy = NULL;
- CBB cbb;
- if (!CBB_init(&cbb, 16) ||
- !CBB_add_u8(&cbb, 0 /* trailing NUL */)) {
- goto cbb_err;
- }
-
- if (BN_is_zero(a)) {
- if (!CBB_add_u8(&cbb, '0')) {
- goto cbb_err;
- }
- } else {
- copy = BN_dup(a);
- if (copy == NULL) {
- goto err;
- }
-
- while (!BN_is_zero(copy)) {
- BN_ULONG word = BN_div_word(copy, BN_DEC_CONV);
- if (word == (BN_ULONG)-1) {
- goto err;
- }
-
- const int add_leading_zeros = !BN_is_zero(copy);
- for (int i = 0; i < BN_DEC_NUM && (add_leading_zeros || word != 0); i++) {
- if (!CBB_add_u8(&cbb, '0' + word % 10)) {
- goto cbb_err;
- }
- word /= 10;
- }
- assert(word == 0);
- }
- }
-
- if (BN_is_negative(a) &&
- !CBB_add_u8(&cbb, '-')) {
- goto cbb_err;
- }
-
- uint8_t *data;
- size_t len;
- if (!CBB_finish(&cbb, &data, &len)) {
- goto cbb_err;
- }
-
- // Reverse the buffer.
- for (size_t i = 0; i < len/2; i++) {
- uint8_t tmp = data[i];
- data[i] = data[len - 1 - i];
- data[len - 1 - i] = tmp;
- }
-
- BN_free(copy);
- return (char *)data;
-
- cbb_err:
- OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE);
- err:
- BN_free(copy);
- CBB_cleanup(&cbb);
- return NULL;
- }
-
- int BN_dec2bn(BIGNUM **outp, const char *in) {
- return bn_x2bn(outp, in, decode_dec, isdigit);
- }
-
- int BN_asc2bn(BIGNUM **outp, const char *in) {
- const char *const orig_in = in;
- if (*in == '-') {
- in++;
- }
-
- if (in[0] == '0' && (in[1] == 'X' || in[1] == 'x')) {
- if (!BN_hex2bn(outp, in+2)) {
- return 0;
- }
- } else {
- if (!BN_dec2bn(outp, in)) {
- return 0;
- }
- }
-
- if (*orig_in == '-' && !BN_is_zero(*outp)) {
- (*outp)->neg = 1;
- }
-
- return 1;
- }
-
- int BN_print(BIO *bp, const BIGNUM *a) {
- int i, j, v, z = 0;
- int ret = 0;
-
- if (a->neg && BIO_write(bp, "-", 1) != 1) {
- goto end;
- }
-
- if (BN_is_zero(a) && BIO_write(bp, "0", 1) != 1) {
- goto end;
- }
-
- for (i = a->top - 1; i >= 0; i--) {
- for (j = BN_BITS2 - 4; j >= 0; j -= 4) {
- // strip leading zeros
- v = ((int)(a->d[i] >> (long)j)) & 0x0f;
- if (z || v != 0) {
- if (BIO_write(bp, &hextable[v], 1) != 1) {
- goto end;
- }
- z = 1;
- }
- }
- }
- ret = 1;
-
- end:
- return ret;
- }
-
- int BN_print_fp(FILE *fp, const BIGNUM *a) {
- BIO *b;
- int ret;
-
- b = BIO_new(BIO_s_file());
- if (b == NULL) {
- return 0;
- }
- BIO_set_fp(b, fp, BIO_NOCLOSE);
- ret = BN_print(b, a);
- BIO_free(b);
-
- return ret;
- }
-
-
- size_t BN_bn2mpi(const BIGNUM *in, uint8_t *out) {
- const size_t bits = BN_num_bits(in);
- const size_t bytes = (bits + 7) / 8;
- // If the number of bits is a multiple of 8, i.e. if the MSB is set,
- // prefix with a zero byte.
- int extend = 0;
- if (bytes != 0 && (bits & 0x07) == 0) {
- extend = 1;
- }
-
- const size_t len = bytes + extend;
- if (len < bytes ||
- 4 + len < len ||
- (len & 0xffffffff) != len) {
- // If we cannot represent the number then we emit zero as the interface
- // doesn't allow an error to be signalled.
- if (out) {
- OPENSSL_memset(out, 0, 4);
- }
- return 4;
- }
-
- if (out == NULL) {
- return 4 + len;
- }
-
- out[0] = len >> 24;
- out[1] = len >> 16;
- out[2] = len >> 8;
- out[3] = len;
- if (extend) {
- out[4] = 0;
- }
- BN_bn2bin(in, out + 4 + extend);
- if (in->neg && len > 0) {
- out[4] |= 0x80;
- }
- return len + 4;
- }
-
- BIGNUM *BN_mpi2bn(const uint8_t *in, size_t len, BIGNUM *out) {
- if (len < 4) {
- OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING);
- return NULL;
- }
- const size_t in_len = ((size_t)in[0] << 24) |
- ((size_t)in[1] << 16) |
- ((size_t)in[2] << 8) |
- ((size_t)in[3]);
- if (in_len != len - 4) {
- OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING);
- return NULL;
- }
-
- int out_is_alloced = 0;
- if (out == NULL) {
- out = BN_new();
- if (out == NULL) {
- OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE);
- return NULL;
- }
- out_is_alloced = 1;
- }
-
- if (in_len == 0) {
- BN_zero(out);
- return out;
- }
-
- in += 4;
- if (BN_bin2bn(in, in_len, out) == NULL) {
- if (out_is_alloced) {
- BN_free(out);
- }
- return NULL;
- }
- out->neg = ((*in) & 0x80) != 0;
- if (out->neg) {
- BN_clear_bit(out, BN_num_bits(out) - 1);
- }
- return out;
- }
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