1 /* crypto/asn1/a_int.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
61 #include <openssl/asn1.h>
63 ASN1_INTEGER *ASN1_INTEGER_dup(ASN1_INTEGER *x)
64 { return M_ASN1_INTEGER_dup(x);}
66 int ASN1_INTEGER_cmp(ASN1_INTEGER *x, ASN1_INTEGER *y)
70 neg = x->type & V_ASN1_NEG;
71 if (neg != (y->type & V_ASN1_NEG))
79 ret = ASN1_STRING_cmp(x, y);
89 * This converts an ASN1 INTEGER into its content encoding.
90 * The internal representation is an ASN1_STRING whose data is a big endian
91 * representation of the value, ignoring the sign. The sign is determined by
92 * the type: V_ASN1_INTEGER for positive and V_ASN1_NEG_INTEGER for negative.
94 * Positive integers are no problem: they are almost the same as the DER
95 * encoding, except if the first byte is >= 0x80 we need to add a zero pad.
97 * Negative integers are a bit trickier...
98 * The DER representation of negative integers is in 2s complement form.
99 * The internal form is converted by complementing each octet and finally
100 * adding one to the result. This can be done less messily with a little trick.
101 * If the internal form has trailing zeroes then they will become FF by the
102 * complement and 0 by the add one (due to carry) so just copy as many trailing
103 * zeros to the destination as there are in the source. The carry will add one
104 * to the last none zero octet: so complement this octet and add one and finally
105 * complement any left over until you get to the start of the string.
107 * Padding is a little trickier too. If the first bytes is > 0x80 then we pad
108 * with 0xff. However if the first byte is 0x80 and one of the following bytes
109 * is non-zero we pad with 0xff. The reason for this distinction is that 0x80
110 * followed by optional zeros isn't padded.
113 int i2c_ASN1_INTEGER(ASN1_INTEGER *a, unsigned char **pp)
116 unsigned char *p,*n,pb=0;
118 if ((a == NULL) || (a->data == NULL)) return(0);
119 neg=a->type & V_ASN1_NEG;
126 if (!neg && (i > 127)) {
133 } else if(i == 128) {
135 * Special case: if any other bytes non zero we pad:
136 * otherwise we don't.
138 for(i = 1; i < a->length; i++) if(a->data[i]) {
147 if (pp == NULL) return(ret);
151 if (a->length == 0) *(p++)=0;
152 else if (!neg) memcpy(p,a->data,(unsigned int)a->length);
154 /* Begin at the end of the encoding */
155 n=a->data + a->length - 1;
158 /* Copy zeros to destination as long as source is zero */
164 /* Complement and increment next octet */
165 *(p--) = ((*(n--)) ^ 0xff) + 1;
167 /* Complement any octets left */
168 for(;i > 0; i--) *(p--) = *(n--) ^ 0xff;
175 /* Convert just ASN1 INTEGER content octets to ASN1_INTEGER structure */
177 ASN1_INTEGER *c2i_ASN1_INTEGER(ASN1_INTEGER **a, unsigned char **pp,
180 ASN1_INTEGER *ret=NULL;
181 unsigned char *p,*to,*s, *pend;
184 if ((a == NULL) || ((*a) == NULL))
186 if ((ret=M_ASN1_INTEGER_new()) == NULL) return(NULL);
187 ret->type=V_ASN1_INTEGER;
195 /* We must OPENSSL_malloc stuff, even for 0 bytes otherwise it
196 * signifies a missing NULL parameter. */
197 s=(unsigned char *)OPENSSL_malloc((int)len+1);
200 i=ERR_R_MALLOC_FAILURE;
205 /* Strictly speaking this is an illegal INTEGER but we
208 ret->type=V_ASN1_INTEGER;
209 } else if (*p & 0x80) /* a negative number */
211 ret->type=V_ASN1_NEG_INTEGER;
212 if ((*p == 0xff) && (len != 1)) {
224 /* Special case: if all zeros then the number will be of
225 * the form FF followed by n zero bytes: this corresponds to
226 * 1 followed by n zero bytes. We've already written n zeros
227 * so we just append an extra one and set the first byte to
228 * a 1. This is treated separately because it is the only case
229 * where the number of bytes is larger than len.
236 *(to--) = (*(p--) ^ 0xff) + 1;
238 for(;i > 0; i--) *(to--) = *(p--) ^ 0xff;
241 ret->type=V_ASN1_INTEGER;
242 if ((*p == 0) && (len != 1))
247 memcpy(s,p,(int)len);
250 if (ret->data != NULL) OPENSSL_free(ret->data);
252 ret->length=(int)len;
253 if (a != NULL) (*a)=ret;
257 ASN1err(ASN1_F_D2I_ASN1_INTEGER,i);
258 if ((ret != NULL) && ((a == NULL) || (*a != ret)))
259 M_ASN1_INTEGER_free(ret);
264 /* This is a version of d2i_ASN1_INTEGER that ignores the sign bit of
265 * ASN1 integers: some broken software can encode a positive INTEGER
266 * with its MSB set as negative (it doesn't add a padding zero).
269 ASN1_INTEGER *d2i_ASN1_UINTEGER(ASN1_INTEGER **a, unsigned char **pp,
272 ASN1_INTEGER *ret=NULL;
273 unsigned char *p,*to,*s;
278 if ((a == NULL) || ((*a) == NULL))
280 if ((ret=M_ASN1_INTEGER_new()) == NULL) return(NULL);
281 ret->type=V_ASN1_INTEGER;
287 inf=ASN1_get_object(&p,&len,&tag,&xclass,length);
290 i=ASN1_R_BAD_OBJECT_HEADER;
294 if (tag != V_ASN1_INTEGER)
296 i=ASN1_R_EXPECTING_AN_INTEGER;
300 /* We must OPENSSL_malloc stuff, even for 0 bytes otherwise it
301 * signifies a missing NULL parameter. */
302 s=(unsigned char *)OPENSSL_malloc((int)len+1);
305 i=ERR_R_MALLOC_FAILURE;
309 ret->type=V_ASN1_INTEGER;
311 if ((*p == 0) && (len != 1))
316 memcpy(s,p,(int)len);
320 if (ret->data != NULL) OPENSSL_free(ret->data);
322 ret->length=(int)len;
323 if (a != NULL) (*a)=ret;
327 ASN1err(ASN1_F_D2I_ASN1_UINTEGER,i);
328 if ((ret != NULL) && ((a == NULL) || (*a != ret)))
329 M_ASN1_INTEGER_free(ret);
333 int ASN1_INTEGER_set(ASN1_INTEGER *a, long v)
336 unsigned char buf[sizeof(long)+1];
339 a->type=V_ASN1_INTEGER;
340 if (a->length < (sizeof(long)+1))
343 OPENSSL_free(a->data);
344 if ((a->data=(unsigned char *)OPENSSL_malloc(sizeof(long)+1)) != NULL)
345 memset((char *)a->data,0,sizeof(long)+1);
349 ASN1err(ASN1_F_ASN1_INTEGER_SET,ERR_R_MALLOC_FAILURE);
356 a->type=V_ASN1_NEG_INTEGER;
359 for (i=0; i<sizeof(long); i++)
366 for (k=i-1; k >=0; k--)
372 long ASN1_INTEGER_get(ASN1_INTEGER *a)
377 if (a == NULL) return(0L);
379 if (i == V_ASN1_NEG_INTEGER)
381 else if (i != V_ASN1_INTEGER)
384 if (a->length > sizeof(long))
386 /* hmm... a bit ugly */
392 for (i=0; i<a->length; i++)
395 r|=(unsigned char)a->data[i];
401 ASN1_INTEGER *BN_to_ASN1_INTEGER(BIGNUM *bn, ASN1_INTEGER *ai)
407 ret=M_ASN1_INTEGER_new();
412 ASN1err(ASN1_F_BN_TO_ASN1_INTEGER,ERR_R_NESTED_ASN1_ERROR);
415 if(bn->neg) ret->type = V_ASN1_NEG_INTEGER;
416 else ret->type=V_ASN1_INTEGER;
418 len=((j == 0)?0:((j/8)+1));
419 if (ret->length < len+4)
421 unsigned char *new_data=OPENSSL_realloc(ret->data, len+4);
424 ASN1err(ASN1_F_BN_TO_ASN1_INTEGER,ERR_R_MALLOC_FAILURE);
429 ret->length=BN_bn2bin(bn,ret->data);
430 /* Correct zero case */
438 if (ret != ai) M_ASN1_INTEGER_free(ret);
442 BIGNUM *ASN1_INTEGER_to_BN(ASN1_INTEGER *ai, BIGNUM *bn)
446 if ((ret=BN_bin2bn(ai->data,ai->length,bn)) == NULL)
447 ASN1err(ASN1_F_ASN1_INTEGER_TO_BN,ASN1_R_BN_LIB);
448 else if(ai->type == V_ASN1_NEG_INTEGER) ret->neg = 1;
452 IMPLEMENT_STACK_OF(ASN1_INTEGER)
453 IMPLEMENT_ASN1_SET_OF(ASN1_INTEGER)