/src/openssl31/crypto/bn/bn_conv.c

Source (jump to first uncovered line)
/*
 * 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;
}

Coverage Report

Created: 2025-06-13 06:58

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9
10		#include <openssl/err.h>
11		#include "crypto/ctype.h"
12		#include "bn_local.h"
13
14		static const char Hex[] = "0123456789ABCDEF";
15
16		/* Must 'OPENSSL_free' the returned data */
17		char BN_bn2hex(const BIGNUM a)
18	52.5k	{
19	52.5k	int i, j, v, z = 0;
20	52.5k	char *buf;
21	52.5k	char *p;
22
23	52.5k	if (BN_is_zero(a))
24	55	return OPENSSL_strdup("0");
25	52.4k	buf = OPENSSL_malloc(a->top * BN_BYTES * 2 + 2);
26	52.4k	if (buf == NULL) {
27	0	ERR_raise(ERR_LIB_BN, ERR_R_MALLOC_FAILURE);
28	0	goto err;
29	0	}
30	52.4k	p = buf;
31	52.4k	if (a->neg)
32	7.83k	*p++ = '-';
33	4.95M	for (i = a->top - 1; i >= 0; i--) {
34	44.0M	for (j = BN_BITS2 - 8; j >= 0; j -= 8) {
35		/* strip leading zeros */
36	39.1M	v = (int)((a->d[i] >> j) & 0xff);
37	39.1M	if (z \|\| v != 0) {
38	38.9M	*p++ = Hex[v >> 4];
39	38.9M	*p++ = Hex[v & 0x0f];
40	38.9M	z = 1;
41	38.9M	}
42	39.1M	}
43	4.89M	}
44	52.4k	*p = '\0';
45	52.4k	err:
46	52.4k	return buf;
47	52.4k	}
48
49		#ifndef FIPS_MODULE
50		/* No BIO_snprintf in FIPS_MODULE */
51		/* Must 'OPENSSL_free' the returned data */
52		char BN_bn2dec(const BIGNUM a)
53	804k	{
54	804k	int i = 0, num, ok = 0, n, tbytes;
55	804k	char *buf = NULL;
56	804k	char *p;
57	804k	BIGNUM *t = NULL;
58	804k	BN_ULONG bn_data = NULL, lp;
59	804k	int bn_data_num;
60
61		/*-
62		* get an upper bound for the length of the decimal integer
63		* num <= (BN_num_bits(a) + 1) * log(2)
64		* <= 3 * BN_num_bits(a) * 0.101 + log(2) + 1 (rounding error)
65		* <= 3 * BN_num_bits(a) / 10 + 3 * BN_num_bits / 1000 + 1 + 1
66		*/
67	804k	i = BN_num_bits(a) * 3;
68	804k	num = (i / 10 + i / 1000 + 1) + 1;
69	804k	tbytes = num + 3; /* negative and terminator and one spare? */
70	804k	bn_data_num = num / BN_DEC_NUM + 1;
71	804k	bn_data = OPENSSL_malloc(bn_data_num * sizeof(BN_ULONG));
72	804k	buf = OPENSSL_malloc(tbytes);
73	804k	if (buf == NULL \|\| bn_data == NULL) {
74	0	ERR_raise(ERR_LIB_BN, ERR_R_MALLOC_FAILURE);
75	0	goto err;
76	0	}
77	804k	if ((t = BN_dup(a)) == NULL)
78	0	goto err;
79
80	804k	p = buf;
81	804k	lp = bn_data;
82	804k	if (BN_is_zero(t)) {
83	58.7k	*p++ = '0';
84	58.7k	*p++ = '\0';
85	745k	} else {
86	745k	if (BN_is_negative(t))
87	106k	*p++ = '-';
88
89	1.72M	while (!BN_is_zero(t)) {
90	981k	if (lp - bn_data >= bn_data_num)
91	0	goto err;
92	981k	*lp = BN_div_word(t, BN_DEC_CONV);
93	981k	if (*lp == (BN_ULONG)-1)
94	0	goto err;
95	981k	lp++;
96	981k	}
97	745k	lp--;
98		/*
99		* We now have a series of blocks, BN_DEC_NUM chars in length, where
100		* the last one needs truncation. The blocks need to be reversed in
101		* order.
102		*/
103	745k	n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT1, *lp);
104	745k	if (n < 0)
105	0	goto err;
106	745k	p += n;
107	981k	while (lp != bn_data) {
108	235k	lp--;
109	235k	n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT2, *lp);
110	235k	if (n < 0)
111	0	goto err;
112	235k	p += n;
113	235k	}
114	745k	}
115	804k	ok = 1;
116	804k	err:
117	804k	OPENSSL_free(bn_data);
118	804k	BN_free(t);
119	804k	if (ok)
120	804k	return buf;
121	0	OPENSSL_free(buf);
122	0	return NULL;
123	804k	}
124		#endif
125
126		int BN_hex2bn(BIGNUM *bn, const char a)
127	0	{
128	0	BIGNUM *ret = NULL;
129	0	BN_ULONG l = 0;
130	0	int neg = 0, h, m, i, j, k, c;
131	0	int num;
132
133	0	if (a == NULL \|\| *a == '\0')
134	0	return 0;
135
136	0	if (*a == '-') {
137	0	neg = 1;
138	0	a++;
139	0	}
140
141	0	for (i = 0; i <= INT_MAX / 4 && ossl_isxdigit(a[i]); i++)
142	0	continue;
143
144	0	if (i == 0 \|\| i > INT_MAX / 4)
145	0	return 0;
146
147	0	num = i + neg;
148	0	if (bn == NULL)
149	0	return num;
150
151		/* a is the start of the hex digits, and it is 'i' long */
152	0	if (*bn == NULL) {
153	0	if ((ret = BN_new()) == NULL)
154	0	return 0;
155	0	} else {
156	0	ret = *bn;
157	0	if (BN_get_flags(ret, BN_FLG_STATIC_DATA)) {
158	0	ERR_raise(ERR_LIB_BN, ERR_R_PASSED_INVALID_ARGUMENT);
159	0	return 0;
160	0	}
161	0	BN_zero(ret);
162	0	}
163
164		/* i is the number of hex digits */
165	0	if (bn_expand(ret, i * 4) == NULL)
166	0	goto err;
167
168	0	j = i; /* least significant 'hex' */
169	0	m = 0;
170	0	h = 0;
171	0	while (j > 0) {
172	0	m = (BN_BYTES * 2 <= j) ? BN_BYTES * 2 : j;
173	0	l = 0;
174	0	for (;;) {
175	0	c = a[j - m];
176	0	k = OPENSSL_hexchar2int(c);
177	0	if (k < 0)
178	0	k = 0; /* paranoia */
179	0	l = (l << 4) \| k;
180
181	0	if (--m <= 0) {
182	0	ret->d[h++] = l;
183	0	break;
184	0	}
185	0	}
186	0	j -= BN_BYTES * 2;
187	0	}
188	0	ret->top = h;
189	0	bn_correct_top(ret);
190
191	0	*bn = ret;
192	0	bn_check_top(ret);
193		/* Don't set the negative flag if it's zero. */
194	0	if (ret->top != 0)
195	0	ret->neg = neg;
196	0	return num;
197	0	err:
198	0	if (*bn == NULL)
199	0	BN_free(ret);
200	0	return 0;
201	0	}
202
203		int BN_dec2bn(BIGNUM *bn, const char a)
204	0	{
205	0	BIGNUM *ret = NULL;
206	0	BN_ULONG l = 0;
207	0	int neg = 0, i, j;
208	0	int num;
209
210	0	if (a == NULL \|\| *a == '\0')
211	0	return 0;
212	0	if (*a == '-') {
213	0	neg = 1;
214	0	a++;
215	0	}
216
217	0	for (i = 0; i <= INT_MAX / 4 && ossl_isdigit(a[i]); i++)
218	0	continue;
219
220	0	if (i == 0 \|\| i > INT_MAX / 4)
221	0	goto err;
222
223	0	num = i + neg;
224	0	if (bn == NULL)
225	0	return num;
226
227		/*
228		* a is the start of the digits, and it is 'i' long. We chop it into
229		* BN_DEC_NUM digits at a time
230		*/
231	0	if (*bn == NULL) {
232	0	if ((ret = BN_new()) == NULL)
233	0	return 0;
234	0	} else {
235	0	ret = *bn;
236	0	BN_zero(ret);
237	0	}
238
239		/* i is the number of digits, a bit of an over expand */
240	0	if (bn_expand(ret, i * 4) == NULL)
241	0	goto err;
242
243	0	j = BN_DEC_NUM - i % BN_DEC_NUM;
244	0	if (j == BN_DEC_NUM)
245	0	j = 0;
246	0	l = 0;
247	0	while (--i >= 0) {
248	0	l *= 10;
249	0	l += *a - '0';
250	0	a++;
251	0	if (++j == BN_DEC_NUM) {
252	0	if (!BN_mul_word(ret, BN_DEC_CONV)
253	0	\|\| !BN_add_word(ret, l))
254	0	goto err;
255	0	l = 0;
256	0	j = 0;
257	0	}
258	0	}
259
260	0	bn_correct_top(ret);
261	0	*bn = ret;
262	0	bn_check_top(ret);
263		/* Don't set the negative flag if it's zero. */
264	0	if (ret->top != 0)
265	0	ret->neg = neg;
266	0	return num;
267	0	err:
268	0	if (*bn == NULL)
269	0	BN_free(ret);
270	0	return 0;
271	0	}
272
273		int BN_asc2bn(BIGNUM *bn, const char a)
274	0	{
275	0	const char *p = a;
276
277	0	if (*p == '-')
278	0	p++;
279
280	0	if (p[0] == '0' && (p[1] == 'X' \|\| p[1] == 'x')) {
281	0	if (!BN_hex2bn(bn, p + 2))
282	0	return 0;
283	0	} else {
284	0	if (!BN_dec2bn(bn, p))
285	0	return 0;
286	0	}
287		/* Don't set the negative flag if it's zero. */
288	0	if (a == '-' && (bn)->top != 0)
289	0	(*bn)->neg = 1;
290	0	return 1;
291	0	}