bn_print.c revision 284285 
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    if (a->neg && BN_is_zero(a)) {
75        /* "-0" == 3 bytes including NULL terminator */
76        buf = OPENSSL_malloc(3);
77    } else {
78        buf = OPENSSL_malloc(a->top * BN_BYTES * 2 + 2);
79    }
80    if (buf == NULL) {
81        BNerr(BN_F_BN_BN2HEX, ERR_R_MALLOC_FAILURE);
82        goto err;
83    }
84    p = buf;
85    if (a->neg)
86        *(p++) = '-';
87    if (BN_is_zero(a))
88        *(p++) = '0';
89    for (i = a->top - 1; i >= 0; i--) {
90        for (j = BN_BITS2 - 8; j >= 0; j -= 8) {
91            /* strip leading zeros */
92            v = ((int)(a->d[i] >> (long)j)) & 0xff;
93            if (z || (v != 0)) {
94                *(p++) = Hex[v >> 4];
95                *(p++) = Hex[v & 0x0f];
96                z = 1;
97            }
98        }
99    }
100    *p = '\0';
101 err:
102    return (buf);
103}
104
105/* Must 'OPENSSL_free' the returned data */
106char *BN_bn2dec(const BIGNUM *a)
107{
108    int i = 0, num, ok = 0;
109    char *buf = NULL;
110    char *p;
111    BIGNUM *t = NULL;
112    BN_ULONG *bn_data = NULL, *lp;
113
114    /*-
115     * get an upper bound for the length of the decimal integer
116     * num <= (BN_num_bits(a) + 1) * log(2)
117     *     <= 3 * BN_num_bits(a) * 0.1001 + log(2) + 1     (rounding error)
118     *     <= BN_num_bits(a)/10 + BN_num_bits/1000 + 1 + 1
119     */
120    i = BN_num_bits(a) * 3;
121    num = (i / 10 + i / 1000 + 1) + 1;
122    bn_data =
123        (BN_ULONG *)OPENSSL_malloc((num / BN_DEC_NUM + 1) * sizeof(BN_ULONG));
124    buf = (char *)OPENSSL_malloc(num + 3);
125    if ((buf == NULL) || (bn_data == NULL)) {
126        BNerr(BN_F_BN_BN2DEC, ERR_R_MALLOC_FAILURE);
127        goto err;
128    }
129    if ((t = BN_dup(a)) == NULL)
130        goto err;
131
132#define BUF_REMAIN (num+3 - (size_t)(p - buf))
133    p = buf;
134    lp = bn_data;
135    if (BN_is_zero(t)) {
136        *(p++) = '0';
137        *(p++) = '\0';
138    } else {
139        if (BN_is_negative(t))
140            *p++ = '-';
141
142        i = 0;
143        while (!BN_is_zero(t)) {
144            *lp = BN_div_word(t, BN_DEC_CONV);
145            lp++;
146        }
147        lp--;
148        /*
149         * We now have a series of blocks, BN_DEC_NUM chars in length, where
150         * the last one needs truncation. The blocks need to be reversed in
151         * order.
152         */
153        BIO_snprintf(p, BUF_REMAIN, BN_DEC_FMT1, *lp);
154        while (*p)
155            p++;
156        while (lp != bn_data) {
157            lp--;
158            BIO_snprintf(p, BUF_REMAIN, BN_DEC_FMT2, *lp);
159            while (*p)
160                p++;
161        }
162    }
163    ok = 1;
164 err:
165    if (bn_data != NULL)
166        OPENSSL_free(bn_data);
167    if (t != NULL)
168        BN_free(t);
169    if (!ok && buf) {
170        OPENSSL_free(buf);
171        buf = NULL;
172    }
173
174    return (buf);
175}
176
177int BN_hex2bn(BIGNUM **bn, const char *a)
178{
179    BIGNUM *ret = NULL;
180    BN_ULONG l = 0;
181    int neg = 0, h, m, i, j, k, c;
182    int num;
183
184    if ((a == NULL) || (*a == '\0'))
185        return (0);
186
187    if (*a == '-') {
188        neg = 1;
189        a++;
190    }
191
192    for (i = 0; isxdigit((unsigned char)a[i]); i++) ;
193
194    num = i + neg;
195    if (bn == NULL)
196        return (num);
197
198    /* a is the start of the hex digits, and it is 'i' long */
199    if (*bn == NULL) {
200        if ((ret = BN_new()) == NULL)
201            return (0);
202    } else {
203        ret = *bn;
204        BN_zero(ret);
205    }
206
207    /* i is the number of hex digests; */
208    if (bn_expand(ret, i * 4) == NULL)
209        goto err;
210
211    j = i;                      /* least significant 'hex' */
212    m = 0;
213    h = 0;
214    while (j > 0) {
215        m = ((BN_BYTES * 2) <= j) ? (BN_BYTES * 2) : j;
216        l = 0;
217        for (;;) {
218            c = a[j - m];
219            if ((c >= '0') && (c <= '9'))
220                k = c - '0';
221            else if ((c >= 'a') && (c <= 'f'))
222                k = c - 'a' + 10;
223            else if ((c >= 'A') && (c <= 'F'))
224                k = c - 'A' + 10;
225            else
226                k = 0;          /* paranoia */
227            l = (l << 4) | k;
228
229            if (--m <= 0) {
230                ret->d[h++] = l;
231                break;
232            }
233        }
234        j -= (BN_BYTES * 2);
235    }
236    ret->top = h;
237    bn_correct_top(ret);
238    ret->neg = neg;
239
240    *bn = ret;
241    bn_check_top(ret);
242    return (num);
243 err:
244    if (*bn == NULL)
245        BN_free(ret);
246    return (0);
247}
248
249int BN_dec2bn(BIGNUM **bn, const char *a)
250{
251    BIGNUM *ret = NULL;
252    BN_ULONG l = 0;
253    int neg = 0, i, j;
254    int num;
255
256    if ((a == NULL) || (*a == '\0'))
257        return (0);
258    if (*a == '-') {
259        neg = 1;
260        a++;
261    }
262
263    for (i = 0; isdigit((unsigned char)a[i]); i++) ;
264
265    num = i + neg;
266    if (bn == NULL)
267        return (num);
268
269    /*
270     * a is the start of the digits, and it is 'i' long. We chop it into
271     * BN_DEC_NUM digits at a time
272     */
273    if (*bn == NULL) {
274        if ((ret = BN_new()) == NULL)
275            return (0);
276    } else {
277        ret = *bn;
278        BN_zero(ret);
279    }
280
281    /* i is the number of digests, a bit of an over expand; */
282    if (bn_expand(ret, i * 4) == NULL)
283        goto err;
284
285    j = BN_DEC_NUM - (i % BN_DEC_NUM);
286    if (j == BN_DEC_NUM)
287        j = 0;
288    l = 0;
289    while (*a) {
290        l *= 10;
291        l += *a - '0';
292        a++;
293        if (++j == BN_DEC_NUM) {
294            BN_mul_word(ret, BN_DEC_CONV);
295            BN_add_word(ret, l);
296            l = 0;
297            j = 0;
298        }
299    }
300    ret->neg = neg;
301
302    bn_correct_top(ret);
303    *bn = ret;
304    bn_check_top(ret);
305    return (num);
306 err:
307    if (*bn == NULL)
308        BN_free(ret);
309    return (0);
310}
311
312int BN_asc2bn(BIGNUM **bn, const char *a)
313{
314    const char *p = a;
315    if (*p == '-')
316        p++;
317
318    if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) {
319        if (!BN_hex2bn(bn, p + 2))
320            return 0;
321    } else {
322        if (!BN_dec2bn(bn, p))
323            return 0;
324    }
325    if (*a == '-')
326        (*bn)->neg = 1;
327    return 1;
328}
329
330#ifndef OPENSSL_NO_BIO
331# ifndef OPENSSL_NO_FP_API
332int BN_print_fp(FILE *fp, const BIGNUM *a)
333{
334    BIO *b;
335    int ret;
336
337    if ((b = BIO_new(BIO_s_file())) == NULL)
338        return (0);
339    BIO_set_fp(b, fp, BIO_NOCLOSE);
340    ret = BN_print(b, a);
341    BIO_free(b);
342    return (ret);
343}
344# endif
345
346int BN_print(BIO *bp, const BIGNUM *a)
347{
348    int i, j, v, z = 0;
349    int ret = 0;
350
351    if ((a->neg) && (BIO_write(bp, "-", 1) != 1))
352        goto end;
353    if (BN_is_zero(a) && (BIO_write(bp, "0", 1) != 1))
354        goto end;
355    for (i = a->top - 1; i >= 0; i--) {
356        for (j = BN_BITS2 - 4; j >= 0; j -= 4) {
357            /* strip leading zeros */
358            v = ((int)(a->d[i] >> (long)j)) & 0x0f;
359            if (z || (v != 0)) {
360                if (BIO_write(bp, &(Hex[v]), 1) != 1)
361                    goto end;
362                z = 1;
363            }
364        }
365    }
366    ret = 1;
367 end:
368    return (ret);
369}
370#endif
371
372char *BN_options(void)
373{
374    static int init = 0;
375    static char data[16];
376
377    if (!init) {
378        init++;
379#ifdef BN_LLONG
380        BIO_snprintf(data, sizeof data, "bn(%d,%d)",
381                     (int)sizeof(BN_ULLONG) * 8, (int)sizeof(BN_ULONG) * 8);
382#else
383        BIO_snprintf(data, sizeof data, "bn(%d,%d)",
384                     (int)sizeof(BN_ULONG) * 8, (int)sizeof(BN_ULONG) * 8);
385#endif
386    }
387    return (data);
388}
389