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