1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2 * All rights reserved.
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.] */
56
57 #include <openssl/asn1.h>
58
59 #include <string.h>
60
61 #include <openssl/err.h>
62 #include <openssl/mem.h>
63
64
ASN1_INTEGER_dup(const ASN1_INTEGER * x)65 ASN1_INTEGER *ASN1_INTEGER_dup(const ASN1_INTEGER *x)
66 { return M_ASN1_INTEGER_dup(x);}
67
ASN1_INTEGER_cmp(const ASN1_INTEGER * x,const ASN1_INTEGER * y)68 int ASN1_INTEGER_cmp(const ASN1_INTEGER *x, const ASN1_INTEGER *y)
69 {
70 int neg, ret;
71 /* Compare signs */
72 neg = x->type & V_ASN1_NEG;
73 if (neg != (y->type & V_ASN1_NEG))
74 {
75 if (neg)
76 return -1;
77 else
78 return 1;
79 }
80
81 ret = ASN1_STRING_cmp(x, y);
82
83 if (neg)
84 return -ret;
85 else
86 return ret;
87 }
88
89
90 /*
91 * This converts an ASN1 INTEGER into its content encoding.
92 * The internal representation is an ASN1_STRING whose data is a big endian
93 * representation of the value, ignoring the sign. The sign is determined by
94 * the type: V_ASN1_INTEGER for positive and V_ASN1_NEG_INTEGER for negative.
95 *
96 * Positive integers are no problem: they are almost the same as the DER
97 * encoding, except if the first byte is >= 0x80 we need to add a zero pad.
98 *
99 * Negative integers are a bit trickier...
100 * The DER representation of negative integers is in 2s complement form.
101 * The internal form is converted by complementing each octet and finally
102 * adding one to the result. This can be done less messily with a little trick.
103 * If the internal form has trailing zeroes then they will become FF by the
104 * complement and 0 by the add one (due to carry) so just copy as many trailing
105 * zeros to the destination as there are in the source. The carry will add one
106 * to the last none zero octet: so complement this octet and add one and finally
107 * complement any left over until you get to the start of the string.
108 *
109 * Padding is a little trickier too. If the first bytes is > 0x80 then we pad
110 * with 0xff. However if the first byte is 0x80 and one of the following bytes
111 * is non-zero we pad with 0xff. The reason for this distinction is that 0x80
112 * followed by optional zeros isn't padded.
113 */
114
i2c_ASN1_INTEGER(ASN1_INTEGER * a,unsigned char ** pp)115 int i2c_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp)
116 {
117 int pad=0,ret,i,neg;
118 unsigned char *p,*n,pb=0;
119
120 if (a == NULL) return(0);
121 neg=a->type & V_ASN1_NEG;
122 if (a->length == 0)
123 ret=1;
124 else
125 {
126 ret=a->length;
127 i=a->data[0];
128 if (ret == 1 && i == 0)
129 neg=0;
130 if (!neg && (i > 127)) {
131 pad=1;
132 pb=0;
133 } else if(neg) {
134 if(i>128) {
135 pad=1;
136 pb=0xFF;
137 } else if(i == 128) {
138 /*
139 * Special case: if any other bytes non zero we pad:
140 * otherwise we don't.
141 */
142 for(i = 1; i < a->length; i++) if(a->data[i]) {
143 pad=1;
144 pb=0xFF;
145 break;
146 }
147 }
148 }
149 ret+=pad;
150 }
151 if (pp == NULL) return(ret);
152 p= *pp;
153
154 if (pad) *(p++)=pb;
155 if (a->length == 0) *(p++)=0;
156 else if (!neg) memcpy(p,a->data,(unsigned int)a->length);
157 else {
158 /* Begin at the end of the encoding */
159 n=a->data + a->length - 1;
160 p += a->length - 1;
161 i = a->length;
162 /* Copy zeros to destination as long as source is zero */
163 while(!*n && i > 1) {
164 *(p--) = 0;
165 n--;
166 i--;
167 }
168 /* Complement and increment next octet */
169 *(p--) = ((*(n--)) ^ 0xff) + 1;
170 i--;
171 /* Complement any octets left */
172 for(;i > 0; i--) *(p--) = *(n--) ^ 0xff;
173 }
174
175 *pp+=ret;
176 return(ret);
177 }
178
179 /* Convert just ASN1 INTEGER content octets to ASN1_INTEGER structure */
180
c2i_ASN1_INTEGER(ASN1_INTEGER ** a,const unsigned char ** pp,long len)181 ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **a, const unsigned char **pp,
182 long len)
183 {
184 ASN1_INTEGER *ret=NULL;
185 const unsigned char *p, *pend;
186 unsigned char *to,*s;
187 int i;
188
189 if ((a == NULL) || ((*a) == NULL))
190 {
191 if ((ret=M_ASN1_INTEGER_new()) == NULL) return(NULL);
192 ret->type=V_ASN1_INTEGER;
193 }
194 else
195 ret=(*a);
196
197 p= *pp;
198 pend = p + len;
199
200 /* We must OPENSSL_malloc stuff, even for 0 bytes otherwise it
201 * signifies a missing NULL parameter. */
202 s=(unsigned char *)OPENSSL_malloc((int)len+1);
203 if (s == NULL)
204 {
205 i=ERR_R_MALLOC_FAILURE;
206 goto err;
207 }
208 to=s;
209 if(!len) {
210 /* Strictly speaking this is an illegal INTEGER but we
211 * tolerate it.
212 */
213 ret->type=V_ASN1_INTEGER;
214 } else if (*p & 0x80) /* a negative number */
215 {
216 ret->type=V_ASN1_NEG_INTEGER;
217 if ((*p == 0xff) && (len != 1)) {
218 p++;
219 len--;
220 }
221 i = len;
222 p += i - 1;
223 to += i - 1;
224 while((!*p) && i) {
225 *(to--) = 0;
226 i--;
227 p--;
228 }
229 /* Special case: if all zeros then the number will be of
230 * the form FF followed by n zero bytes: this corresponds to
231 * 1 followed by n zero bytes. We've already written n zeros
232 * so we just append an extra one and set the first byte to
233 * a 1. This is treated separately because it is the only case
234 * where the number of bytes is larger than len.
235 */
236 if(!i) {
237 *s = 1;
238 s[len] = 0;
239 len++;
240 } else {
241 *(to--) = (*(p--) ^ 0xff) + 1;
242 i--;
243 for(;i > 0; i--) *(to--) = *(p--) ^ 0xff;
244 }
245 } else {
246 ret->type=V_ASN1_INTEGER;
247 if ((*p == 0) && (len != 1))
248 {
249 p++;
250 len--;
251 }
252 memcpy(s,p,(int)len);
253 }
254
255 if (ret->data != NULL) OPENSSL_free(ret->data);
256 ret->data=s;
257 ret->length=(int)len;
258 if (a != NULL) (*a)=ret;
259 *pp=pend;
260 return(ret);
261 err:
262 OPENSSL_PUT_ERROR(ASN1, c2i_ASN1_INTEGER, i);
263 if ((ret != NULL) && ((a == NULL) || (*a != ret)))
264 M_ASN1_INTEGER_free(ret);
265 return(NULL);
266 }
267
268
269 /* This is a version of d2i_ASN1_INTEGER that ignores the sign bit of
270 * ASN1 integers: some broken software can encode a positive INTEGER
271 * with its MSB set as negative (it doesn't add a padding zero).
272 */
273
d2i_ASN1_UINTEGER(ASN1_INTEGER ** a,const unsigned char ** pp,long length)274 ASN1_INTEGER *d2i_ASN1_UINTEGER(ASN1_INTEGER **a, const unsigned char **pp,
275 long length)
276 {
277 ASN1_INTEGER *ret=NULL;
278 const unsigned char *p;
279 unsigned char *s;
280 long len;
281 int inf,tag,xclass;
282 int i;
283
284 if ((a == NULL) || ((*a) == NULL))
285 {
286 if ((ret=M_ASN1_INTEGER_new()) == NULL) return(NULL);
287 ret->type=V_ASN1_INTEGER;
288 }
289 else
290 ret=(*a);
291
292 p= *pp;
293 inf=ASN1_get_object(&p,&len,&tag,&xclass,length);
294 if (inf & 0x80)
295 {
296 i=ASN1_R_BAD_OBJECT_HEADER;
297 goto err;
298 }
299
300 if (tag != V_ASN1_INTEGER)
301 {
302 i=ASN1_R_EXPECTING_AN_INTEGER;
303 goto err;
304 }
305
306 /* We must OPENSSL_malloc stuff, even for 0 bytes otherwise it
307 * signifies a missing NULL parameter. */
308 s=(unsigned char *)OPENSSL_malloc((int)len+1);
309 if (s == NULL)
310 {
311 i=ERR_R_MALLOC_FAILURE;
312 goto err;
313 }
314 ret->type=V_ASN1_INTEGER;
315 if(len) {
316 if ((*p == 0) && (len != 1))
317 {
318 p++;
319 len--;
320 }
321 memcpy(s,p,(int)len);
322 p+=len;
323 }
324
325 if (ret->data != NULL) OPENSSL_free(ret->data);
326 ret->data=s;
327 ret->length=(int)len;
328 if (a != NULL) (*a)=ret;
329 *pp=p;
330 return(ret);
331 err:
332 OPENSSL_PUT_ERROR(ASN1, d2i_ASN1_UINTEGER, i);
333 if ((ret != NULL) && ((a == NULL) || (*a != ret)))
334 M_ASN1_INTEGER_free(ret);
335 return(NULL);
336 }
337
ASN1_INTEGER_set(ASN1_INTEGER * a,long v)338 int ASN1_INTEGER_set(ASN1_INTEGER *a, long v)
339 {
340 int j,k;
341 unsigned int i;
342 unsigned char buf[sizeof(long)+1];
343 long d;
344
345 a->type=V_ASN1_INTEGER;
346 if (a->length < (int)(sizeof(long)+1))
347 {
348 if (a->data != NULL)
349 OPENSSL_free(a->data);
350 if ((a->data=(unsigned char *)OPENSSL_malloc(sizeof(long)+1)) != NULL)
351 memset((char *)a->data,0,sizeof(long)+1);
352 }
353 if (a->data == NULL)
354 {
355 OPENSSL_PUT_ERROR(ASN1, ASN1_INTEGER_set, ERR_R_MALLOC_FAILURE);
356 return(0);
357 }
358 d=v;
359 if (d < 0)
360 {
361 d= -d;
362 a->type=V_ASN1_NEG_INTEGER;
363 }
364
365 for (i=0; i<sizeof(long); i++)
366 {
367 if (d == 0) break;
368 buf[i]=(int)d&0xff;
369 d>>=8;
370 }
371 j=0;
372 for (k=i-1; k >=0; k--)
373 a->data[j++]=buf[k];
374 a->length=j;
375 return(1);
376 }
377
ASN1_INTEGER_get(const ASN1_INTEGER * a)378 long ASN1_INTEGER_get(const ASN1_INTEGER *a)
379 {
380 int neg=0,i;
381 long r=0;
382
383 if (a == NULL) return(0L);
384 i=a->type;
385 if (i == V_ASN1_NEG_INTEGER)
386 neg=1;
387 else if (i != V_ASN1_INTEGER)
388 return -1;
389
390 if (a->length > (int)sizeof(long))
391 {
392 /* hmm... a bit ugly, return all ones */
393 return -1;
394 }
395 if (a->data == NULL)
396 return 0;
397
398 for (i=0; i<a->length; i++)
399 {
400 r<<=8;
401 r|=(unsigned char)a->data[i];
402 }
403 if (neg) r= -r;
404 return(r);
405 }
406
BN_to_ASN1_INTEGER(const BIGNUM * bn,ASN1_INTEGER * ai)407 ASN1_INTEGER *BN_to_ASN1_INTEGER(const BIGNUM *bn, ASN1_INTEGER *ai)
408 {
409 ASN1_INTEGER *ret;
410 int len,j;
411
412 if (ai == NULL)
413 ret=M_ASN1_INTEGER_new();
414 else
415 ret=ai;
416 if (ret == NULL)
417 {
418 OPENSSL_PUT_ERROR(ASN1, BN_to_ASN1_INTEGER, ASN1_R_NESTED_ASN1_ERROR);
419 goto err;
420 }
421 if (BN_is_negative(bn) && !BN_is_zero(bn))
422 ret->type = V_ASN1_NEG_INTEGER;
423 else ret->type=V_ASN1_INTEGER;
424 j=BN_num_bits(bn);
425 len=((j == 0)?0:((j/8)+1));
426 if (ret->length < len+4)
427 {
428 unsigned char *new_data=OPENSSL_realloc(ret->data, len+4);
429 if (!new_data)
430 {
431 OPENSSL_PUT_ERROR(ASN1, BN_to_ASN1_INTEGER, ERR_R_MALLOC_FAILURE);
432 goto err;
433 }
434 ret->data=new_data;
435 }
436 ret->length=BN_bn2bin(bn,ret->data);
437 /* Correct zero case */
438 if(!ret->length)
439 {
440 ret->data[0] = 0;
441 ret->length = 1;
442 }
443 return(ret);
444 err:
445 if (ret != ai) M_ASN1_INTEGER_free(ret);
446 return(NULL);
447 }
448
ASN1_INTEGER_to_BN(const ASN1_INTEGER * ai,BIGNUM * bn)449 BIGNUM *ASN1_INTEGER_to_BN(const ASN1_INTEGER *ai, BIGNUM *bn)
450 {
451 BIGNUM *ret;
452
453 if ((ret=BN_bin2bn(ai->data,ai->length,bn)) == NULL)
454 OPENSSL_PUT_ERROR(ASN1, ASN1_INTEGER_to_BN, ASN1_R_BN_LIB);
455 else if(ai->type == V_ASN1_NEG_INTEGER)
456 BN_set_negative(ret, 1);
457 return(ret);
458 }
459