2 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include "internal/cryptlib.h"
12 #include "internal/numbers.h"
14 #include <openssl/asn1.h>
15 #include <openssl/bn.h>
16 #include "asn1_local.h"
18 ASN1_INTEGER
*ASN1_INTEGER_dup(const ASN1_INTEGER
*x
)
20 return ASN1_STRING_dup(x
);
23 int ASN1_INTEGER_cmp(const ASN1_INTEGER
*x
, const ASN1_INTEGER
*y
)
27 neg
= x
->type
& V_ASN1_NEG
;
28 if (neg
!= (y
->type
& V_ASN1_NEG
)) {
35 ret
= ASN1_STRING_cmp(x
, y
);
44 * This converts a big endian buffer and sign into its content encoding.
45 * This is used for INTEGER and ENUMERATED types.
46 * The internal representation is an ASN1_STRING whose data is a big endian
47 * representation of the value, ignoring the sign. The sign is determined by
48 * the type: if type & V_ASN1_NEG is true it is negative, otherwise positive.
50 * Positive integers are no problem: they are almost the same as the DER
51 * encoding, except if the first byte is >= 0x80 we need to add a zero pad.
53 * Negative integers are a bit trickier...
54 * The DER representation of negative integers is in 2s complement form.
55 * The internal form is converted by complementing each octet and finally
56 * adding one to the result. This can be done less messily with a little trick.
57 * If the internal form has trailing zeroes then they will become FF by the
58 * complement and 0 by the add one (due to carry) so just copy as many trailing
59 * zeros to the destination as there are in the source. The carry will add one
60 * to the last none zero octet: so complement this octet and add one and finally
61 * complement any left over until you get to the start of the string.
63 * Padding is a little trickier too. If the first bytes is > 0x80 then we pad
64 * with 0xff. However if the first byte is 0x80 and one of the following bytes
65 * is non-zero we pad with 0xff. The reason for this distinction is that 0x80
66 * followed by optional zeros isn't padded.
70 * If |pad| is zero, the operation is effectively reduced to memcpy,
71 * and if |pad| is 0xff, then it performs two's complement, ~dst + 1.
72 * Note that in latter case sequence of zeros yields itself, and so
73 * does 0x80 followed by any number of zeros. These properties are
74 * used elsewhere below...
76 static void twos_complement(unsigned char *dst
, const unsigned char *src
,
77 size_t len
, unsigned char pad
)
79 unsigned int carry
= pad
& 1;
81 /* Begin at the end of the encoding */
84 * if len == 0 then src/dst could be NULL, and this would be undefined
90 /* two's complement value: ~value + 1 */
92 *(--dst
) = (unsigned char)(carry
+= *(--src
) ^ pad
);
97 static size_t i2c_ibuf(const unsigned char *b
, size_t blen
, int neg
,
100 unsigned int pad
= 0;
102 unsigned char *p
, pb
= 0;
104 if (b
!= NULL
&& blen
) {
107 if (!neg
&& (i
> 127)) {
114 } else if (i
== 128) {
116 * Special case [of minimal negative for given length]:
117 * if any other bytes non zero we pad, otherwise we don't.
119 for (pad
= 0, i
= 1; i
< blen
; i
++)
121 pb
= pad
!= 0 ? 0xffU
: 0;
128 blen
= 0; /* reduce '(b == NULL || blen == 0)' to '(blen == 0)' */
131 if (pp
== NULL
|| (p
= *pp
) == NULL
)
135 * This magically handles all corner cases, such as '(b == NULL ||
136 * blen == 0)', non-negative value, "negative" zero, 0x80 followed
137 * by any number of zeros...
140 p
+= pad
; /* yes, p[0] can be written twice, but it's little
141 * price to pay for eliminated branches */
142 twos_complement(p
, b
, blen
, pb
);
149 * convert content octets into a big endian buffer. Returns the length
150 * of buffer or 0 on error: for malformed INTEGER. If output buffer is
151 * NULL just return length.
154 static size_t c2i_ibuf(unsigned char *b
, int *pneg
,
155 const unsigned char *p
, size_t plen
)
158 /* Zero content length is illegal */
160 ERR_raise(ERR_LIB_ASN1
, ASN1_R_ILLEGAL_ZERO_CONTENT
);
166 /* Handle common case where length is 1 octet separately */
170 b
[0] = (p
[0] ^ 0xFF) + 1;
180 } else if (p
[0] == 0xFF) {
184 * Special case [of "one less minimal negative" for given length]:
185 * if any other bytes non zero it was padded, otherwise not.
187 for (pad
= 0, i
= 1; i
< plen
; i
++)
189 pad
= pad
!= 0 ? 1 : 0;
191 /* reject illegal padding: first two octets MSB can't match */
192 if (pad
&& (neg
== (p
[1] & 0x80))) {
193 ERR_raise(ERR_LIB_ASN1
, ASN1_R_ILLEGAL_PADDING
);
202 twos_complement(b
, p
, plen
, neg
? 0xffU
: 0);
207 int ossl_i2c_ASN1_INTEGER(ASN1_INTEGER
*a
, unsigned char **pp
)
209 return i2c_ibuf(a
->data
, a
->length
, a
->type
& V_ASN1_NEG
, pp
);
212 /* Convert big endian buffer into uint64_t, return 0 on error */
213 static int asn1_get_uint64(uint64_t *pr
, const unsigned char *b
, size_t blen
)
218 if (blen
> sizeof(*pr
)) {
219 ERR_raise(ERR_LIB_ASN1
, ASN1_R_TOO_LARGE
);
224 for (r
= 0, i
= 0; i
< blen
; i
++) {
233 * Write uint64_t to big endian buffer and return offset to first
234 * written octet. In other words it returns offset in range from 0
235 * to 7, with 0 denoting 8 written octets and 7 - one.
237 static size_t asn1_put_uint64(unsigned char b
[sizeof(uint64_t)], uint64_t r
)
239 size_t off
= sizeof(uint64_t);
242 b
[--off
] = (unsigned char)r
;
249 * Absolute value of INT64_MIN: we can't just use -INT64_MIN as gcc produces
252 #define ABS_INT64_MIN ((uint64_t)INT64_MAX + (-(INT64_MIN + INT64_MAX)))
254 /* signed version of asn1_get_uint64 */
255 static int asn1_get_int64(int64_t *pr
, const unsigned char *b
, size_t blen
,
259 if (asn1_get_uint64(&r
, b
, blen
) == 0)
262 if (r
<= INT64_MAX
) {
263 /* Most significant bit is guaranteed to be clear, negation
264 * is guaranteed to be meaningful in platform-neutral sense. */
266 } else if (r
== ABS_INT64_MIN
) {
267 /* This never happens if INT64_MAX == ABS_INT64_MIN, e.g.
268 * on ones'-complement system. */
269 *pr
= (int64_t)(0 - r
);
271 ERR_raise(ERR_LIB_ASN1
, ASN1_R_TOO_SMALL
);
275 if (r
<= INT64_MAX
) {
278 ERR_raise(ERR_LIB_ASN1
, ASN1_R_TOO_LARGE
);
285 /* Convert ASN1 INTEGER content octets to ASN1_INTEGER structure */
286 ASN1_INTEGER
*ossl_c2i_ASN1_INTEGER(ASN1_INTEGER
**a
, const unsigned char **pp
,
289 ASN1_INTEGER
*ret
= NULL
;
293 r
= c2i_ibuf(NULL
, NULL
, *pp
, len
);
298 if ((a
== NULL
) || ((*a
) == NULL
)) {
299 ret
= ASN1_INTEGER_new();
302 ret
->type
= V_ASN1_INTEGER
;
306 if (ASN1_STRING_set(ret
, NULL
, r
) == 0)
309 c2i_ibuf(ret
->data
, &neg
, *pp
, len
);
312 ret
->type
|= V_ASN1_NEG
;
314 ret
->type
&= ~V_ASN1_NEG
;
321 ERR_raise(ERR_LIB_ASN1
, ERR_R_MALLOC_FAILURE
);
322 if (a
== NULL
|| *a
!= ret
)
323 ASN1_INTEGER_free(ret
);
327 static int asn1_string_get_int64(int64_t *pr
, const ASN1_STRING
*a
, int itype
)
330 ERR_raise(ERR_LIB_ASN1
, ERR_R_PASSED_NULL_PARAMETER
);
333 if ((a
->type
& ~V_ASN1_NEG
) != itype
) {
334 ERR_raise(ERR_LIB_ASN1
, ASN1_R_WRONG_INTEGER_TYPE
);
337 return asn1_get_int64(pr
, a
->data
, a
->length
, a
->type
& V_ASN1_NEG
);
340 static int asn1_string_set_int64(ASN1_STRING
*a
, int64_t r
, int itype
)
342 unsigned char tbuf
[sizeof(r
)];
347 /* Most obvious '-r' triggers undefined behaviour for most
348 * common INT64_MIN. Even though below '0 - (uint64_t)r' can
349 * appear two's-complement centric, it does produce correct/
350 * expected result even on one's-complement. This is because
351 * cast to unsigned has to change bit pattern... */
352 off
= asn1_put_uint64(tbuf
, 0 - (uint64_t)r
);
353 a
->type
|= V_ASN1_NEG
;
355 off
= asn1_put_uint64(tbuf
, r
);
356 a
->type
&= ~V_ASN1_NEG
;
358 return ASN1_STRING_set(a
, tbuf
+ off
, sizeof(tbuf
) - off
);
361 static int asn1_string_get_uint64(uint64_t *pr
, const ASN1_STRING
*a
,
365 ERR_raise(ERR_LIB_ASN1
, ERR_R_PASSED_NULL_PARAMETER
);
368 if ((a
->type
& ~V_ASN1_NEG
) != itype
) {
369 ERR_raise(ERR_LIB_ASN1
, ASN1_R_WRONG_INTEGER_TYPE
);
372 if (a
->type
& V_ASN1_NEG
) {
373 ERR_raise(ERR_LIB_ASN1
, ASN1_R_ILLEGAL_NEGATIVE_VALUE
);
376 return asn1_get_uint64(pr
, a
->data
, a
->length
);
379 static int asn1_string_set_uint64(ASN1_STRING
*a
, uint64_t r
, int itype
)
381 unsigned char tbuf
[sizeof(r
)];
385 off
= asn1_put_uint64(tbuf
, r
);
386 return ASN1_STRING_set(a
, tbuf
+ off
, sizeof(tbuf
) - off
);
390 * This is a version of d2i_ASN1_INTEGER that ignores the sign bit of ASN1
391 * integers: some broken software can encode a positive INTEGER with its MSB
392 * set as negative (it doesn't add a padding zero).
395 ASN1_INTEGER
*d2i_ASN1_UINTEGER(ASN1_INTEGER
**a
, const unsigned char **pp
,
398 ASN1_INTEGER
*ret
= NULL
;
399 const unsigned char *p
;
402 int inf
, tag
, xclass
;
405 if ((a
== NULL
) || ((*a
) == NULL
)) {
406 if ((ret
= ASN1_INTEGER_new()) == NULL
)
408 ret
->type
= V_ASN1_INTEGER
;
413 inf
= ASN1_get_object(&p
, &len
, &tag
, &xclass
, length
);
415 i
= ASN1_R_BAD_OBJECT_HEADER
;
419 if (tag
!= V_ASN1_INTEGER
) {
420 i
= ASN1_R_EXPECTING_AN_INTEGER
;
425 * We must OPENSSL_malloc stuff, even for 0 bytes otherwise it signifies
426 * a missing NULL parameter.
428 s
= OPENSSL_malloc((int)len
+ 1);
430 i
= ERR_R_MALLOC_FAILURE
;
433 ret
->type
= V_ASN1_INTEGER
;
435 if ((*p
== 0) && (len
!= 1)) {
439 memcpy(s
, p
, (int)len
);
443 OPENSSL_free(ret
->data
);
445 ret
->length
= (int)len
;
451 ERR_raise(ERR_LIB_ASN1
, i
);
452 if ((a
== NULL
) || (*a
!= ret
))
453 ASN1_INTEGER_free(ret
);
457 static ASN1_STRING
*bn_to_asn1_string(const BIGNUM
*bn
, ASN1_STRING
*ai
,
464 ret
= ASN1_STRING_type_new(atype
);
471 ERR_raise(ERR_LIB_ASN1
, ERR_R_NESTED_ASN1_ERROR
);
475 if (BN_is_negative(bn
) && !BN_is_zero(bn
))
476 ret
->type
|= V_ASN1_NEG_INTEGER
;
478 len
= BN_num_bytes(bn
);
483 if (ASN1_STRING_set(ret
, NULL
, len
) == 0) {
484 ERR_raise(ERR_LIB_ASN1
, ERR_R_MALLOC_FAILURE
);
488 /* Correct zero case */
492 len
= BN_bn2bin(bn
, ret
->data
);
497 ASN1_INTEGER_free(ret
);
501 static BIGNUM
*asn1_string_to_bn(const ASN1_INTEGER
*ai
, BIGNUM
*bn
,
506 if ((ai
->type
& ~V_ASN1_NEG
) != itype
) {
507 ERR_raise(ERR_LIB_ASN1
, ASN1_R_WRONG_INTEGER_TYPE
);
511 ret
= BN_bin2bn(ai
->data
, ai
->length
, bn
);
513 ERR_raise(ERR_LIB_ASN1
, ASN1_R_BN_LIB
);
516 if (ai
->type
& V_ASN1_NEG
)
517 BN_set_negative(ret
, 1);
521 int ASN1_INTEGER_get_int64(int64_t *pr
, const ASN1_INTEGER
*a
)
523 return asn1_string_get_int64(pr
, a
, V_ASN1_INTEGER
);
526 int ASN1_INTEGER_set_int64(ASN1_INTEGER
*a
, int64_t r
)
528 return asn1_string_set_int64(a
, r
, V_ASN1_INTEGER
);
531 int ASN1_INTEGER_get_uint64(uint64_t *pr
, const ASN1_INTEGER
*a
)
533 return asn1_string_get_uint64(pr
, a
, V_ASN1_INTEGER
);
536 int ASN1_INTEGER_set_uint64(ASN1_INTEGER
*a
, uint64_t r
)
538 return asn1_string_set_uint64(a
, r
, V_ASN1_INTEGER
);
541 int ASN1_INTEGER_set(ASN1_INTEGER
*a
, long v
)
543 return ASN1_INTEGER_set_int64(a
, v
);
546 long ASN1_INTEGER_get(const ASN1_INTEGER
*a
)
552 i
= ASN1_INTEGER_get_int64(&r
, a
);
555 if (r
> LONG_MAX
|| r
< LONG_MIN
)
560 ASN1_INTEGER
*BN_to_ASN1_INTEGER(const BIGNUM
*bn
, ASN1_INTEGER
*ai
)
562 return bn_to_asn1_string(bn
, ai
, V_ASN1_INTEGER
);
565 BIGNUM
*ASN1_INTEGER_to_BN(const ASN1_INTEGER
*ai
, BIGNUM
*bn
)
567 return asn1_string_to_bn(ai
, bn
, V_ASN1_INTEGER
);
570 int ASN1_ENUMERATED_get_int64(int64_t *pr
, const ASN1_ENUMERATED
*a
)
572 return asn1_string_get_int64(pr
, a
, V_ASN1_ENUMERATED
);
575 int ASN1_ENUMERATED_set_int64(ASN1_ENUMERATED
*a
, int64_t r
)
577 return asn1_string_set_int64(a
, r
, V_ASN1_ENUMERATED
);
580 int ASN1_ENUMERATED_set(ASN1_ENUMERATED
*a
, long v
)
582 return ASN1_ENUMERATED_set_int64(a
, v
);
585 long ASN1_ENUMERATED_get(const ASN1_ENUMERATED
*a
)
591 if ((a
->type
& ~V_ASN1_NEG
) != V_ASN1_ENUMERATED
)
593 if (a
->length
> (int)sizeof(long))
595 i
= ASN1_ENUMERATED_get_int64(&r
, a
);
598 if (r
> LONG_MAX
|| r
< LONG_MIN
)
603 ASN1_ENUMERATED
*BN_to_ASN1_ENUMERATED(const BIGNUM
*bn
, ASN1_ENUMERATED
*ai
)
605 return bn_to_asn1_string(bn
, ai
, V_ASN1_ENUMERATED
);
608 BIGNUM
*ASN1_ENUMERATED_to_BN(const ASN1_ENUMERATED
*ai
, BIGNUM
*bn
)
610 return asn1_string_to_bn(ai
, bn
, V_ASN1_ENUMERATED
);
613 /* Internal functions used by x_int64.c */
614 int ossl_c2i_uint64_int(uint64_t *ret
, int *neg
,
615 const unsigned char **pp
, long len
)
617 unsigned char buf
[sizeof(uint64_t)];
620 buflen
= c2i_ibuf(NULL
, NULL
, *pp
, len
);
623 if (buflen
> sizeof(uint64_t)) {
624 ERR_raise(ERR_LIB_ASN1
, ASN1_R_TOO_LARGE
);
627 (void)c2i_ibuf(buf
, neg
, *pp
, len
);
628 return asn1_get_uint64(ret
, buf
, buflen
);
631 int ossl_i2c_uint64_int(unsigned char *p
, uint64_t r
, int neg
)
633 unsigned char buf
[sizeof(uint64_t)];
636 off
= asn1_put_uint64(buf
, r
);
637 return i2c_ibuf(buf
+ off
, sizeof(buf
) - off
, neg
, &p
);