bn_print.c revision 284295 
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		{
82		BNerr(BN_F_BN_BN2HEX,ERR_R_MALLOC_FAILURE);
83		goto err;
84		}
85	p=buf;
86	if (a->neg) *(p++)='-';
87	if (BN_is_zero(a)) *(p++)='0';
88	for (i=a->top-1; i >=0; i--)
89		{
90		for (j=BN_BITS2-8; j >= 0; j-=8)
91			{
92			/* strip leading zeros */
93			v=((int)(a->d[i]>>(long)j))&0xff;
94			if (z || (v != 0))
95				{
96				*(p++)=Hex[v>>4];
97				*(p++)=Hex[v&0x0f];
98				z=1;
99				}
100			}
101		}
102	*p='\0';
103err:
104	return(buf);
105	}
106
107/* Must 'OPENSSL_free' the returned data */
108char *BN_bn2dec(const BIGNUM *a)
109	{
110	int i=0,num, ok = 0;
111	char *buf=NULL;
112	char *p;
113	BIGNUM *t=NULL;
114	BN_ULONG *bn_data=NULL,*lp;
115
116	/* get an upper bound for the length of the decimal integer
117	 * num <= (BN_num_bits(a) + 1) * log(2)
118	 *     <= 3 * BN_num_bits(a) * 0.1001 + log(2) + 1     (rounding error)
119	 *     <= BN_num_bits(a)/10 + BN_num_bits/1000 + 1 + 1
120	 */
121	i=BN_num_bits(a)*3;
122	num=(i/10+i/1000+1)+1;
123	bn_data=(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		{
127		BNerr(BN_F_BN_BN2DEC,ERR_R_MALLOC_FAILURE);
128		goto err;
129		}
130	if ((t=BN_dup(a)) == NULL) 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		{
137		*(p++)='0';
138		*(p++)='\0';
139		}
140	else
141		{
142		if (BN_is_negative(t))
143			*p++ = '-';
144
145		i=0;
146		while (!BN_is_zero(t))
147			{
148			*lp=BN_div_word(t,BN_DEC_CONV);
149			lp++;
150			}
151		lp--;
152		/* We now have a series of blocks, BN_DEC_NUM chars
153		 * in length, where the last one needs truncation.
154		 * The blocks need to be reversed in order. */
155		BIO_snprintf(p,BUF_REMAIN,BN_DEC_FMT1,*lp);
156		while (*p) p++;
157		while (lp != bn_data)
158			{
159			lp--;
160			BIO_snprintf(p,BUF_REMAIN,BN_DEC_FMT2,*lp);
161			while (*p) p++;
162			}
163		}
164	ok = 1;
165err:
166	if (bn_data != NULL) OPENSSL_free(bn_data);
167	if (t != NULL) BN_free(t);
168	if (!ok && buf)
169		{
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')) return(0);
185
186	if (*a == '-') { neg=1; a++; }
187
188	for (i=0; isxdigit((unsigned char) a[i]); i++)
189		;
190
191	num=i+neg;
192	if (bn == NULL) return(num);
193
194	/* a is the start of the hex digits, and it is 'i' long */
195	if (*bn == NULL)
196		{
197		if ((ret=BN_new()) == NULL) return(0);
198		}
199	else
200		{
201		ret= *bn;
202		BN_zero(ret);
203		}
204
205	/* i is the number of hex digests; */
206	if (bn_expand(ret,i*4) == NULL) goto err;
207
208	j=i; /* least significant 'hex' */
209	m=0;
210	h=0;
211	while (j > 0)
212		{
213		m=((BN_BYTES*2) <= j)?(BN_BYTES*2):j;
214		l=0;
215		for (;;)
216			{
217			c=a[j-m];
218			if ((c >= '0') && (c <= '9')) k=c-'0';
219			else if ((c >= 'a') && (c <= 'f')) k=c-'a'+10;
220			else if ((c >= 'A') && (c <= 'F')) k=c-'A'+10;
221			else k=0; /* paranoia */
222			l=(l<<4)|k;
223
224			if (--m <= 0)
225				{
226				ret->d[h++]=l;
227				break;
228				}
229			}
230		j-=(BN_BYTES*2);
231		}
232	ret->top=h;
233	bn_correct_top(ret);
234	ret->neg=neg;
235
236	*bn=ret;
237	bn_check_top(ret);
238	return(num);
239err:
240	if (*bn == NULL) 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')) return(0);
252	if (*a == '-') { neg=1; a++; }
253
254	for (i=0; isdigit((unsigned char) a[i]); i++)
255		;
256
257	num=i+neg;
258	if (bn == NULL) return(num);
259
260	/* a is the start of the digits, and it is 'i' long.
261	 * We chop it into BN_DEC_NUM digits at a time */
262	if (*bn == NULL)
263		{
264		if ((ret=BN_new()) == NULL) return(0);
265		}
266	else
267		{
268		ret= *bn;
269		BN_zero(ret);
270		}
271
272	/* i is the number of digests, a bit of an over expand; */
273	if (bn_expand(ret,i*4) == NULL) goto err;
274
275	j=BN_DEC_NUM-(i%BN_DEC_NUM);
276	if (j == BN_DEC_NUM) j=0;
277	l=0;
278	while (*a)
279		{
280		l*=10;
281		l+= *a-'0';
282		a++;
283		if (++j == BN_DEC_NUM)
284			{
285			BN_mul_word(ret,BN_DEC_CONV);
286			BN_add_word(ret,l);
287			l=0;
288			j=0;
289			}
290		}
291	ret->neg=neg;
292
293	bn_correct_top(ret);
294	*bn=ret;
295	bn_check_top(ret);
296	return(num);
297err:
298	if (*bn == NULL) BN_free(ret);
299	return(0);
300	}
301
302int BN_asc2bn(BIGNUM **bn, const char *a)
303	{
304	const char *p = a;
305	if (*p == '-')
306		p++;
307
308	if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x'))
309		{
310		if (!BN_hex2bn(bn, p + 2))
311			return 0;
312		}
313	else
314		{
315		if (!BN_dec2bn(bn, p))
316			return 0;
317		}
318	if (*a == '-')
319		(*bn)->neg = 1;
320	return 1;
321	}
322
323#ifndef OPENSSL_NO_BIO
324#ifndef OPENSSL_NO_FP_API
325int BN_print_fp(FILE *fp, const BIGNUM *a)
326	{
327	BIO *b;
328	int ret;
329
330	if ((b=BIO_new(BIO_s_file())) == NULL)
331		return(0);
332	BIO_set_fp(b,fp,BIO_NOCLOSE);
333	ret=BN_print(b,a);
334	BIO_free(b);
335	return(ret);
336	}
337#endif
338
339int BN_print(BIO *bp, const BIGNUM *a)
340	{
341	int i,j,v,z=0;
342	int ret=0;
343
344	if ((a->neg) && (BIO_write(bp,"-",1) != 1)) goto end;
345	if (BN_is_zero(a) && (BIO_write(bp,"0",1) != 1)) goto end;
346	for (i=a->top-1; i >=0; i--)
347		{
348		for (j=BN_BITS2-4; j >= 0; j-=4)
349			{
350			/* strip leading zeros */
351			v=((int)(a->d[i]>>(long)j))&0x0f;
352			if (z || (v != 0))
353				{
354				if (BIO_write(bp,&(Hex[v]),1) != 1)
355					goto end;
356				z=1;
357				}
358			}
359		}
360	ret=1;
361end:
362	return(ret);
363	}
364#endif
365
366char *BN_options(void)
367	{
368	static int init=0;
369	static char data[16];
370
371	if (!init)
372		{
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