1e71b7053SJung-uk Kim /*
258f35182SJung-uk Kim * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
374664626SKris Kennaway *
4b077aed3SPierre Pronchery * Licensed under the Apache License 2.0 (the "License"). You may not use
5e71b7053SJung-uk Kim * this file except in compliance with the License. You can obtain a copy
6e71b7053SJung-uk Kim * in the file LICENSE in the source distribution or at
7e71b7053SJung-uk Kim * https://www.openssl.org/source/license.html
874664626SKris Kennaway */
974664626SKris Kennaway
1074664626SKris Kennaway #include <stdio.h>
11e71b7053SJung-uk Kim #include "internal/cryptlib.h"
1217f01e99SJung-uk Kim #include "bn_local.h"
1374664626SKris Kennaway
BN_bn2mpi(const BIGNUM * a,unsigned char * d)1474664626SKris Kennaway int BN_bn2mpi(const BIGNUM *a, unsigned char *d)
1574664626SKris Kennaway {
1674664626SKris Kennaway int bits;
1774664626SKris Kennaway int num = 0;
1874664626SKris Kennaway int ext = 0;
1974664626SKris Kennaway long l;
2074664626SKris Kennaway
2174664626SKris Kennaway bits = BN_num_bits(a);
2274664626SKris Kennaway num = (bits + 7) / 8;
236f9291ceSJung-uk Kim if (bits > 0) {
2474664626SKris Kennaway ext = ((bits & 0x07) == 0);
2574664626SKris Kennaway }
2674664626SKris Kennaway if (d == NULL)
2774664626SKris Kennaway return (num + 4 + ext);
2874664626SKris Kennaway
2974664626SKris Kennaway l = num + ext;
3074664626SKris Kennaway d[0] = (unsigned char)(l >> 24) & 0xff;
3174664626SKris Kennaway d[1] = (unsigned char)(l >> 16) & 0xff;
3274664626SKris Kennaway d[2] = (unsigned char)(l >> 8) & 0xff;
3374664626SKris Kennaway d[3] = (unsigned char)(l) & 0xff;
346f9291ceSJung-uk Kim if (ext)
356f9291ceSJung-uk Kim d[4] = 0;
3674664626SKris Kennaway num = BN_bn2bin(a, &(d[4 + ext]));
3774664626SKris Kennaway if (a->neg)
3874664626SKris Kennaway d[4] |= 0x80;
3974664626SKris Kennaway return (num + 4 + ext);
4074664626SKris Kennaway }
4174664626SKris Kennaway
BN_mpi2bn(const unsigned char * d,int n,BIGNUM * ain)42e71b7053SJung-uk Kim BIGNUM *BN_mpi2bn(const unsigned char *d, int n, BIGNUM *ain)
4374664626SKris Kennaway {
4474664626SKris Kennaway long len;
4574664626SKris Kennaway int neg = 0;
46e71b7053SJung-uk Kim BIGNUM *a = NULL;
4774664626SKris Kennaway
4858f35182SJung-uk Kim if (n < 4 || (d[0] & 0x80) != 0) {
49b077aed3SPierre Pronchery ERR_raise(ERR_LIB_BN, BN_R_INVALID_LENGTH);
50e71b7053SJung-uk Kim return NULL;
5174664626SKris Kennaway }
526f9291ceSJung-uk Kim len = ((long)d[0] << 24) | ((long)d[1] << 16) | ((int)d[2] << 8) | (int)
536f9291ceSJung-uk Kim d[3];
546f9291ceSJung-uk Kim if ((len + 4) != n) {
55b077aed3SPierre Pronchery ERR_raise(ERR_LIB_BN, BN_R_ENCODING_ERROR);
56e71b7053SJung-uk Kim return NULL;
5774664626SKris Kennaway }
5874664626SKris Kennaway
59e71b7053SJung-uk Kim if (ain == NULL)
606f9291ceSJung-uk Kim a = BN_new();
61e71b7053SJung-uk Kim else
62e71b7053SJung-uk Kim a = ain;
63e71b7053SJung-uk Kim
646f9291ceSJung-uk Kim if (a == NULL)
65e71b7053SJung-uk Kim return NULL;
6674664626SKris Kennaway
676f9291ceSJung-uk Kim if (len == 0) {
6874664626SKris Kennaway a->neg = 0;
6974664626SKris Kennaway a->top = 0;
70e71b7053SJung-uk Kim return a;
7174664626SKris Kennaway }
7274664626SKris Kennaway d += 4;
7374664626SKris Kennaway if ((*d) & 0x80)
7474664626SKris Kennaway neg = 1;
75e71b7053SJung-uk Kim if (BN_bin2bn(d, (int)len, a) == NULL) {
76e71b7053SJung-uk Kim if (ain == NULL)
77e71b7053SJung-uk Kim BN_free(a);
78e71b7053SJung-uk Kim return NULL;
79e71b7053SJung-uk Kim }
8074664626SKris Kennaway a->neg = neg;
816f9291ceSJung-uk Kim if (neg) {
8274664626SKris Kennaway BN_clear_bit(a, BN_num_bits(a) - 1);
8374664626SKris Kennaway }
843b4e3dcbSSimon L. B. Nielsen bn_check_top(a);
85e71b7053SJung-uk Kim return a;
8674664626SKris Kennaway }
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