bn_print.c revision 280304 
1/* crypto/bn/bn_print.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59#include <stdio.h>
60#include <ctype.h>
61#include "cryptlib.h"
62#include <openssl/buffer.h>
63#include "bn_lcl.h"
64
65static const char Hex[] = "0123456789ABCDEF";
66
67/* Must 'OPENSSL_free' the returned data */
68char *BN_bn2hex(const BIGNUM *a)
69{
70    int i, j, v, z = 0;
71    char *buf;
72    char *p;
73
74    buf = (char *)OPENSSL_malloc(a->top * BN_BYTES * 2 + 2);
75    if (buf == NULL) {
76        BNerr(BN_F_BN_BN2HEX, ERR_R_MALLOC_FAILURE);
77        goto err;
78    }
79    p = buf;
80    if (a->neg)
81        *(p++) = '-';
82    if (BN_is_zero(a))
83        *(p++) = '0';
84    for (i = a->top - 1; i >= 0; i--) {
85        for (j = BN_BITS2 - 8; j >= 0; j -= 8) {
86            /* strip leading zeros */
87            v = ((int)(a->d[i] >> (long)j)) & 0xff;
88            if (z || (v != 0)) {
89                *(p++) = Hex[v >> 4];
90                *(p++) = Hex[v & 0x0f];
91                z = 1;
92            }
93        }
94    }
95    *p = '\0';
96 err:
97    return (buf);
98}
99
100/* Must 'OPENSSL_free' the returned data */
101char *BN_bn2dec(const BIGNUM *a)
102{
103    int i = 0, num, ok = 0;
104    char *buf = NULL;
105    char *p;
106    BIGNUM *t = NULL;
107    BN_ULONG *bn_data = NULL, *lp;
108
109    /*-
110     * get an upper bound for the length of the decimal integer
111     * num <= (BN_num_bits(a) + 1) * log(2)
112     *     <= 3 * BN_num_bits(a) * 0.1001 + log(2) + 1     (rounding error)
113     *     <= BN_num_bits(a)/10 + BN_num_bits/1000 + 1 + 1
114     */
115    i = BN_num_bits(a) * 3;
116    num = (i / 10 + i / 1000 + 1) + 1;
117    bn_data =
118        (BN_ULONG *)OPENSSL_malloc((num / BN_DEC_NUM + 1) * sizeof(BN_ULONG));
119    buf = (char *)OPENSSL_malloc(num + 3);
120    if ((buf == NULL) || (bn_data == NULL)) {
121        BNerr(BN_F_BN_BN2DEC, ERR_R_MALLOC_FAILURE);
122        goto err;
123    }
124    if ((t = BN_dup(a)) == NULL)
125        goto err;
126
127#define BUF_REMAIN (num+3 - (size_t)(p - buf))
128    p = buf;
129    lp = bn_data;
130    if (BN_is_zero(t)) {
131        *(p++) = '0';
132        *(p++) = '\0';
133    } else {
134        if (BN_is_negative(t))
135            *p++ = '-';
136
137        i = 0;
138        while (!BN_is_zero(t)) {
139            *lp = BN_div_word(t, BN_DEC_CONV);
140            lp++;
141        }
142        lp--;
143        /*
144         * We now have a series of blocks, BN_DEC_NUM chars in length, where
145         * the last one needs truncation. The blocks need to be reversed in
146         * order.
147         */
148        BIO_snprintf(p, BUF_REMAIN, BN_DEC_FMT1, *lp);
149        while (*p)
150            p++;
151        while (lp != bn_data) {
152            lp--;
153            BIO_snprintf(p, BUF_REMAIN, BN_DEC_FMT2, *lp);
154            while (*p)
155                p++;
156        }
157    }
158    ok = 1;
159 err:
160    if (bn_data != NULL)
161        OPENSSL_free(bn_data);
162    if (t != NULL)
163        BN_free(t);
164    if (!ok && buf) {
165        OPENSSL_free(buf);
166        buf = NULL;
167    }
168
169    return (buf);
170}
171
172int BN_hex2bn(BIGNUM **bn, const char *a)
173{
174    BIGNUM *ret = NULL;
175    BN_ULONG l = 0;
176    int neg = 0, h, m, i, j, k, c;
177    int num;
178
179    if ((a == NULL) || (*a == '\0'))
180        return (0);
181
182    if (*a == '-') {
183        neg = 1;
184        a++;
185    }
186
187    for (i = 0; isxdigit((unsigned char)a[i]); i++) ;
188
189    num = i + neg;
190    if (bn == NULL)
191        return (num);
192
193    /* a is the start of the hex digits, and it is 'i' long */
194    if (*bn == NULL) {
195        if ((ret = BN_new()) == NULL)
196            return (0);
197    } else {
198        ret = *bn;
199        BN_zero(ret);
200    }
201
202    /* i is the number of hex digests; */
203    if (bn_expand(ret, i * 4) == NULL)
204        goto err;
205
206    j = i;                      /* least significant 'hex' */
207    m = 0;
208    h = 0;
209    while (j > 0) {
210        m = ((BN_BYTES * 2) <= j) ? (BN_BYTES * 2) : j;
211        l = 0;
212        for (;;) {
213            c = a[j - m];
214            if ((c >= '0') && (c <= '9'))
215                k = c - '0';
216            else if ((c >= 'a') && (c <= 'f'))
217                k = c - 'a' + 10;
218            else if ((c >= 'A') && (c <= 'F'))
219                k = c - 'A' + 10;
220            else
221                k = 0;          /* paranoia */
222            l = (l << 4) | k;
223
224            if (--m <= 0) {
225                ret->d[h++] = l;
226                break;
227            }
228        }
229        j -= (BN_BYTES * 2);
230    }
231    ret->top = h;
232    bn_correct_top(ret);
233    ret->neg = neg;
234
235    *bn = ret;
236    bn_check_top(ret);
237    return (num);
238 err:
239    if (*bn == NULL)
240        BN_free(ret);
241    return (0);
242}
243
244int BN_dec2bn(BIGNUM **bn, const char *a)
245{
246    BIGNUM *ret = NULL;
247    BN_ULONG l = 0;
248    int neg = 0, i, j;
249    int num;
250
251    if ((a == NULL) || (*a == '\0'))
252        return (0);
253    if (*a == '-') {
254        neg = 1;
255        a++;
256    }
257
258    for (i = 0; isdigit((unsigned char)a[i]); i++) ;
259
260    num = i + neg;
261    if (bn == NULL)
262        return (num);
263
264    /*
265     * a is the start of the digits, and it is 'i' long. We chop it into
266     * BN_DEC_NUM digits at a time
267     */
268    if (*bn == NULL) {
269        if ((ret = BN_new()) == NULL)
270            return (0);
271    } else {
272        ret = *bn;
273        BN_zero(ret);
274    }
275
276    /* i is the number of digests, a bit of an over expand; */
277    if (bn_expand(ret, i * 4) == NULL)
278        goto err;
279
280    j = BN_DEC_NUM - (i % BN_DEC_NUM);
281    if (j == BN_DEC_NUM)
282        j = 0;
283    l = 0;
284    while (*a) {
285        l *= 10;
286        l += *a - '0';
287        a++;
288        if (++j == BN_DEC_NUM) {
289            BN_mul_word(ret, BN_DEC_CONV);
290            BN_add_word(ret, l);
291            l = 0;
292            j = 0;
293        }
294    }
295    ret->neg = neg;
296
297    bn_correct_top(ret);
298    *bn = ret;
299    bn_check_top(ret);
300    return (num);
301 err:
302    if (*bn == NULL)
303        BN_free(ret);
304    return (0);
305}
306
307int BN_asc2bn(BIGNUM **bn, const char *a)
308{
309    const char *p = a;
310    if (*p == '-')
311        p++;
312
313    if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) {
314        if (!BN_hex2bn(bn, p + 2))
315            return 0;
316    } else {
317        if (!BN_dec2bn(bn, p))
318            return 0;
319    }
320    if (*a == '-')
321        (*bn)->neg = 1;
322    return 1;
323}
324
325#ifndef OPENSSL_NO_BIO
326# ifndef OPENSSL_NO_FP_API
327int BN_print_fp(FILE *fp, const BIGNUM *a)
328{
329    BIO *b;
330    int ret;
331
332    if ((b = BIO_new(BIO_s_file())) == NULL)
333        return (0);
334    BIO_set_fp(b, fp, BIO_NOCLOSE);
335    ret = BN_print(b, a);
336    BIO_free(b);
337    return (ret);
338}
339# endif
340
341int BN_print(BIO *bp, const BIGNUM *a)
342{
343    int i, j, v, z = 0;
344    int ret = 0;
345
346    if ((a->neg) && (BIO_write(bp, "-", 1) != 1))
347        goto end;
348    if (BN_is_zero(a) && (BIO_write(bp, "0", 1) != 1))
349        goto end;
350    for (i = a->top - 1; i >= 0; i--) {
351        for (j = BN_BITS2 - 4; j >= 0; j -= 4) {
352            /* strip leading zeros */
353            v = ((int)(a->d[i] >> (long)j)) & 0x0f;
354            if (z || (v != 0)) {
355                if (BIO_write(bp, &(Hex[v]), 1) != 1)
356                    goto end;
357                z = 1;
358            }
359        }
360    }
361    ret = 1;
362 end:
363    return (ret);
364}
365#endif
366
367char *BN_options(void)
368{
369    static int init = 0;
370    static char data[16];
371
372    if (!init) {
373        init++;
374#ifdef BN_LLONG
375        BIO_snprintf(data, sizeof data, "bn(%d,%d)",
376                     (int)sizeof(BN_ULLONG) * 8, (int)sizeof(BN_ULONG) * 8);
377#else
378        BIO_snprintf(data, sizeof data, "bn(%d,%d)",
379                     (int)sizeof(BN_ULONG) * 8, (int)sizeof(BN_ULONG) * 8);
380#endif
381    }
382    return (data);
383}
384