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 
65 static const char Hex[]="0123456789ABCDEF";
66 
67 /* Must 'OPENSSL_free' the returned data */
68 char *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';
98 err:
99 	return(buf);
100 	}
101 
102 /* Must 'OPENSSL_free' the returned data */
103 char *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;
160 err:
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 
172 int 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);
234 err:
235 	if (*bn == NULL) BN_free(ret);
236 	return(0);
237 	}
238 
239 int 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);
292 err:
293 	if (*bn == NULL) BN_free(ret);
294 	return(0);
295 	}
296 
297 int 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
320 int 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 
334 int 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;
356 end:
357 	return(ret);
358 	}
359 #endif
360