| /* |
| * Copyright 1995-2020 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 <openssl/err.h> |
| #include "crypto/ctype.h" |
| #include "bn_local.h" |
| |
| static const char Hex[] = "0123456789ABCDEF"; |
| |
| /* Must 'OPENSSL_free' the returned data */ |
| char *BN_bn2hex(const BIGNUM *a) |
| { |
| int i, j, v, z = 0; |
| char *buf; |
| char *p; |
| |
| if (BN_is_zero(a)) |
| return OPENSSL_strdup("0"); |
| buf = OPENSSL_malloc(a->top * BN_BYTES * 2 + 2); |
| if (buf == NULL) { |
| ERR_raise(ERR_LIB_BN, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| p = buf; |
| if (a->neg) |
| *p++ = '-'; |
| for (i = a->top - 1; i >= 0; i--) { |
| for (j = BN_BITS2 - 8; j >= 0; j -= 8) { |
| /* strip leading zeros */ |
| v = (int)((a->d[i] >> j) & 0xff); |
| if (z || v != 0) { |
| *p++ = Hex[v >> 4]; |
| *p++ = Hex[v & 0x0f]; |
| z = 1; |
| } |
| } |
| } |
| *p = '\0'; |
| err: |
| return buf; |
| } |
| |
| #ifndef FIPS_MODULE |
| /* No BIO_snprintf in FIPS_MODULE */ |
| /* Must 'OPENSSL_free' the returned data */ |
| char *BN_bn2dec(const BIGNUM *a) |
| { |
| int i = 0, num, ok = 0, n, tbytes; |
| char *buf = NULL; |
| char *p; |
| BIGNUM *t = NULL; |
| BN_ULONG *bn_data = NULL, *lp; |
| int bn_data_num; |
| |
| /*- |
| * get an upper bound for the length of the decimal integer |
| * num <= (BN_num_bits(a) + 1) * log(2) |
| * <= 3 * BN_num_bits(a) * 0.101 + log(2) + 1 (rounding error) |
| * <= 3 * BN_num_bits(a) / 10 + 3 * BN_num_bits / 1000 + 1 + 1 |
| */ |
| i = BN_num_bits(a) * 3; |
| num = (i / 10 + i / 1000 + 1) + 1; |
| tbytes = num + 3; /* negative and terminator and one spare? */ |
| bn_data_num = num / BN_DEC_NUM + 1; |
| bn_data = OPENSSL_malloc(bn_data_num * sizeof(BN_ULONG)); |
| buf = OPENSSL_malloc(tbytes); |
| if (buf == NULL || bn_data == NULL) { |
| ERR_raise(ERR_LIB_BN, ERR_R_MALLOC_FAILURE); |
| goto err; |
| } |
| if ((t = BN_dup(a)) == NULL) |
| goto err; |
| |
| p = buf; |
| lp = bn_data; |
| if (BN_is_zero(t)) { |
| *p++ = '0'; |
| *p++ = '\0'; |
| } else { |
| if (BN_is_negative(t)) |
| *p++ = '-'; |
| |
| while (!BN_is_zero(t)) { |
| if (lp - bn_data >= bn_data_num) |
| goto err; |
| *lp = BN_div_word(t, BN_DEC_CONV); |
| if (*lp == (BN_ULONG)-1) |
| goto err; |
| lp++; |
| } |
| lp--; |
| /* |
| * We now have a series of blocks, BN_DEC_NUM chars in length, where |
| * the last one needs truncation. The blocks need to be reversed in |
| * order. |
| */ |
| n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT1, *lp); |
| if (n < 0) |
| goto err; |
| p += n; |
| while (lp != bn_data) { |
| lp--; |
| n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT2, *lp); |
| if (n < 0) |
| goto err; |
| p += n; |
| } |
| } |
| ok = 1; |
| err: |
| OPENSSL_free(bn_data); |
| BN_free(t); |
| if (ok) |
| return buf; |
| OPENSSL_free(buf); |
| return NULL; |
| } |
| #endif |
| |
| int BN_hex2bn(BIGNUM **bn, const char *a) |
| { |
| BIGNUM *ret = NULL; |
| BN_ULONG l = 0; |
| int neg = 0, h, m, i, j, k, c; |
| int num; |
| |
| if (a == NULL || *a == '\0') |
| return 0; |
| |
| if (*a == '-') { |
| neg = 1; |
| a++; |
| } |
| |
| for (i = 0; i <= INT_MAX / 4 && ossl_isxdigit(a[i]); i++) |
| continue; |
| |
| if (i == 0 || i > INT_MAX / 4) |
| return 0; |
| |
| num = i + neg; |
| if (bn == NULL) |
| return num; |
| |
| /* a is the start of the hex digits, and it is 'i' long */ |
| if (*bn == NULL) { |
| if ((ret = BN_new()) == NULL) |
| return 0; |
| } else { |
| ret = *bn; |
| if (BN_get_flags(ret, BN_FLG_STATIC_DATA)) { |
| ERR_raise(ERR_LIB_BN, ERR_R_PASSED_INVALID_ARGUMENT); |
| return 0; |
| } |
| BN_zero(ret); |
| } |
| |
| /* i is the number of hex digits */ |
| if (bn_expand(ret, i * 4) == NULL) |
| goto err; |
| |
| j = i; /* least significant 'hex' */ |
| m = 0; |
| h = 0; |
| while (j > 0) { |
| m = (BN_BYTES * 2 <= j) ? BN_BYTES * 2 : j; |
| l = 0; |
| for (;;) { |
| c = a[j - m]; |
| k = OPENSSL_hexchar2int(c); |
| if (k < 0) |
| k = 0; /* paranoia */ |
| l = (l << 4) | k; |
| |
| if (--m <= 0) { |
| ret->d[h++] = l; |
| break; |
| } |
| } |
| j -= BN_BYTES * 2; |
| } |
| ret->top = h; |
| bn_correct_top(ret); |
| |
| *bn = ret; |
| bn_check_top(ret); |
| /* Don't set the negative flag if it's zero. */ |
| if (ret->top != 0) |
| ret->neg = neg; |
| return num; |
| err: |
| if (*bn == NULL) |
| BN_free(ret); |
| return 0; |
| } |
| |
| int BN_dec2bn(BIGNUM **bn, const char *a) |
| { |
| BIGNUM *ret = NULL; |
| BN_ULONG l = 0; |
| int neg = 0, i, j; |
| int num; |
| |
| if (a == NULL || *a == '\0') |
| return 0; |
| if (*a == '-') { |
| neg = 1; |
| a++; |
| } |
| |
| for (i = 0; i <= INT_MAX / 4 && ossl_isdigit(a[i]); i++) |
| continue; |
| |
| if (i == 0 || i > INT_MAX / 4) |
| goto err; |
| |
| num = i + neg; |
| if (bn == NULL) |
| return num; |
| |
| /* |
| * a is the start of the digits, and it is 'i' long. We chop it into |
| * BN_DEC_NUM digits at a time |
| */ |
| if (*bn == NULL) { |
| if ((ret = BN_new()) == NULL) |
| return 0; |
| } else { |
| ret = *bn; |
| BN_zero(ret); |
| } |
| |
| /* i is the number of digits, a bit of an over expand */ |
| if (bn_expand(ret, i * 4) == NULL) |
| goto err; |
| |
| j = BN_DEC_NUM - i % BN_DEC_NUM; |
| if (j == BN_DEC_NUM) |
| j = 0; |
| l = 0; |
| while (--i >= 0) { |
| l *= 10; |
| l += *a - '0'; |
| a++; |
| if (++j == BN_DEC_NUM) { |
| if (!BN_mul_word(ret, BN_DEC_CONV) |
| || !BN_add_word(ret, l)) |
| goto err; |
| l = 0; |
| j = 0; |
| } |
| } |
| |
| bn_correct_top(ret); |
| *bn = ret; |
| bn_check_top(ret); |
| /* Don't set the negative flag if it's zero. */ |
| if (ret->top != 0) |
| ret->neg = neg; |
| return num; |
| err: |
| if (*bn == NULL) |
| BN_free(ret); |
| return 0; |
| } |
| |
| int BN_asc2bn(BIGNUM **bn, const char *a) |
| { |
| const char *p = a; |
| |
| if (*p == '-') |
| p++; |
| |
| if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) { |
| if (!BN_hex2bn(bn, p + 2)) |
| return 0; |
| } else { |
| if (!BN_dec2bn(bn, p)) |
| return 0; |
| } |
| /* Don't set the negative flag if it's zero. */ |
| if (*a == '-' && (*bn)->top != 0) |
| (*bn)->neg = 1; |
| return 1; |
| } |
