tasn_enc.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/* tasn_enc.c */
/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
* project 2000.
*/
/* ====================================================================
* Copyright (c) 2000 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include <stddef.h>
#include <string.h>
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/objects.h>
static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass);
static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *seq, unsigned char **out, int skcontlen, const ASN1_ITEM *item, int isset);
/* Encode an ASN1 item, this is compatible with the
* standard 'i2d' function. 'out' points to
* a buffer to output the data to, in future we will
* have more advanced versions that can output data
* a piece at a time and this will simply be a special
* case.
*
* The new i2d has one additional feature. If the output
* buffer is NULL (i.e. *out == NULL) then a buffer is
* allocated and populated with the encoding.
*/
int ASN1_item_i2d(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it)
{
if(out && !*out) {
unsigned char *p, *buf;
int len;
len = ASN1_item_ex_i2d(&val, NULL, it, -1, 0);
if(len <= 0) return len;
buf = OPENSSL_malloc(len);
if(!buf) return -1;
p = buf;
ASN1_item_ex_i2d(&val, &p, it, -1, 0);
*out = buf;
return len;
}
return ASN1_item_ex_i2d(&val, out, it, -1, 0);
}
/* Encode an item, taking care of IMPLICIT tagging (if any).
* This function performs the normal item handling: it can be
* used in external types.
*/
int ASN1_item_ex_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass)
{
const ASN1_TEMPLATE *tt = NULL;
unsigned char *p = NULL;
int i, seqcontlen, seqlen;
ASN1_STRING *strtmp;
const ASN1_COMPAT_FUNCS *cf;
const ASN1_EXTERN_FUNCS *ef;
const ASN1_AUX *aux = it->funcs;
ASN1_aux_cb *asn1_cb;
if((it->itype != ASN1_ITYPE_PRIMITIVE) && !*pval) return 0;
if(aux && aux->asn1_cb) asn1_cb = aux->asn1_cb;
else asn1_cb = 0;
switch(it->itype) {
case ASN1_ITYPE_PRIMITIVE:
if(it->templates)
return ASN1_template_i2d(pval, out, it->templates);
return asn1_i2d_ex_primitive(pval, out, it, tag, aclass);
break;
case ASN1_ITYPE_MSTRING:
strtmp = (ASN1_STRING *)*pval;
return asn1_i2d_ex_primitive(pval, out, it, -1, 0);
case ASN1_ITYPE_CHOICE:
if(asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it))
return 0;
i = asn1_get_choice_selector(pval, it);
if((i >= 0) && (i < it->tcount)) {
ASN1_VALUE **pchval;
const ASN1_TEMPLATE *chtt;
chtt = it->templates + i;
pchval = asn1_get_field_ptr(pval, chtt);
return ASN1_template_i2d(pchval, out, chtt);
}
/* Fixme: error condition if selector out of range */
if(asn1_cb && !asn1_cb(ASN1_OP_I2D_POST, pval, it))
return 0;
break;
case ASN1_ITYPE_EXTERN:
/* If new style i2d it does all the work */
ef = it->funcs;
return ef->asn1_ex_i2d(pval, out, it, tag, aclass);
case ASN1_ITYPE_COMPAT:
/* old style hackery... */
cf = it->funcs;
if(out) p = *out;
i = cf->asn1_i2d(*pval, out);
/* Fixup for IMPLICIT tag: note this messes up for tags > 30,
* but so did the old code. Tags > 30 are very rare anyway.
*/
if(out && (tag != -1))
*p = aclass | tag | (*p & V_ASN1_CONSTRUCTED);
return i;
case ASN1_ITYPE_SEQUENCE:
i = asn1_enc_restore(&seqcontlen, out, pval, it);
/* An error occurred */
if(i < 0) return 0;
/* We have a valid cached encoding... */
if(i > 0) return seqcontlen;
/* Otherwise carry on */
seqcontlen = 0;
/* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
if(tag == -1) {
tag = V_ASN1_SEQUENCE;
aclass = V_ASN1_UNIVERSAL;
}
if(asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it))
return 0;
/* First work out sequence content length */
for(i = 0, tt = it->templates; i < it->tcount; tt++, i++) {
const ASN1_TEMPLATE *seqtt;
ASN1_VALUE **pseqval;
seqtt = asn1_do_adb(pval, tt, 1);
if(!seqtt) return 0;
pseqval = asn1_get_field_ptr(pval, seqtt);
/* FIXME: check for errors in enhanced version */
/* FIXME: special handling of indefinite length encoding */
seqcontlen += ASN1_template_i2d(pseqval, NULL, seqtt);
}
seqlen = ASN1_object_size(1, seqcontlen, tag);
if(!out) return seqlen;
/* Output SEQUENCE header */
ASN1_put_object(out, 1, seqcontlen, tag, aclass);
for(i = 0, tt = it->templates; i < it->tcount; tt++, i++) {
const ASN1_TEMPLATE *seqtt;
ASN1_VALUE **pseqval;
seqtt = asn1_do_adb(pval, tt, 1);
if(!seqtt) return 0;
pseqval = asn1_get_field_ptr(pval, seqtt);
/* FIXME: check for errors in enhanced version */
ASN1_template_i2d(pseqval, out, seqtt);
}
if(asn1_cb && !asn1_cb(ASN1_OP_I2D_POST, pval, it))
return 0;
return seqlen;
default:
return 0;
}
return 0;
}
int ASN1_template_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_TEMPLATE *tt)
{
int i, ret, flags, aclass;
flags = tt->flags;
aclass = flags & ASN1_TFLG_TAG_CLASS;
if(flags & ASN1_TFLG_SK_MASK) {
/* SET OF, SEQUENCE OF */
STACK_OF(ASN1_VALUE) *sk = (STACK_OF(ASN1_VALUE) *)*pval;
int isset, sktag, skaclass;
int skcontlen, sklen;
ASN1_VALUE *skitem;
if(!*pval) return 0;
if(flags & ASN1_TFLG_SET_OF) {
isset = 1;
/* 2 means we reorder */
if(flags & ASN1_TFLG_SEQUENCE_OF) isset = 2;
} else isset = 0;
/* First work out inner tag value */
if(flags & ASN1_TFLG_IMPTAG) {
sktag = tt->tag;
skaclass = aclass;
} else {
skaclass = V_ASN1_UNIVERSAL;
if(isset) sktag = V_ASN1_SET;
else sktag = V_ASN1_SEQUENCE;
}
/* Now work out length of items */
skcontlen = 0;
for(i = 0; i < sk_ASN1_VALUE_num(sk); i++) {
skitem = sk_ASN1_VALUE_value(sk, i);
skcontlen += ASN1_item_ex_i2d(&skitem, NULL, ASN1_ITEM_ptr(tt->item), -1, 0);
}
sklen = ASN1_object_size(1, skcontlen, sktag);
/* If EXPLICIT need length of surrounding tag */
if(flags & ASN1_TFLG_EXPTAG)
ret = ASN1_object_size(1, sklen, tt->tag);
else ret = sklen;
if(!out) return ret;
/* Now encode this lot... */
/* EXPLICIT tag */
if(flags & ASN1_TFLG_EXPTAG)
ASN1_put_object(out, 1, sklen, tt->tag, aclass);
/* SET or SEQUENCE and IMPLICIT tag */
ASN1_put_object(out, 1, skcontlen, sktag, skaclass);
/* And finally the stuff itself */
asn1_set_seq_out(sk, out, skcontlen, ASN1_ITEM_ptr(tt->item), isset);
return ret;
}
if(flags & ASN1_TFLG_EXPTAG) {
/* EXPLICIT tagging */
/* Find length of tagged item */
i = ASN1_item_ex_i2d(pval, NULL, ASN1_ITEM_ptr(tt->item), -1, 0);
if(!i) return 0;
/* Find length of EXPLICIT tag */
ret = ASN1_object_size(1, i, tt->tag);
if(out) {
/* Output tag and item */
ASN1_put_object(out, 1, i, tt->tag, aclass);
ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), -1, 0);
}
return ret;
}
if(flags & ASN1_TFLG_IMPTAG) {
/* IMPLICIT tagging */
return ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), tt->tag, aclass);
}
/* Nothing special: treat as normal */
return ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item), -1, 0);
}
/* Temporary structure used to hold DER encoding of items for SET OF */
typedef struct {
unsigned char *data;
int length;
ASN1_VALUE *field;
} DER_ENC;
static int der_cmp(const void *a, const void *b)
{
const DER_ENC *d1 = a, *d2 = b;
int cmplen, i;
cmplen = (d1->length < d2->length) ? d1->length : d2->length;
i = memcmp(d1->data, d2->data, cmplen);
if(i) return i;
return d1->length - d2->length;
}
/* Output the content octets of SET OF or SEQUENCE OF */
static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *sk, unsigned char **out, int skcontlen, const ASN1_ITEM *item, int do_sort)
{
int i;
ASN1_VALUE *skitem;
unsigned char *tmpdat = NULL, *p = NULL;
DER_ENC *derlst = NULL, *tder;
if(do_sort) {
/* Don't need to sort less than 2 items */
if(sk_ASN1_VALUE_num(sk) < 2) do_sort = 0;
else {
derlst = OPENSSL_malloc(sk_ASN1_VALUE_num(sk) * sizeof(*derlst));
tmpdat = OPENSSL_malloc(skcontlen);
if(!derlst || !tmpdat) return 0;
}
}
/* If not sorting just output each item */
if(!do_sort) {
for(i = 0; i < sk_ASN1_VALUE_num(sk); i++) {
skitem = sk_ASN1_VALUE_value(sk, i);
ASN1_item_i2d(skitem, out, item);
}
return 1;
}
p = tmpdat;
/* Doing sort: build up a list of each member's DER encoding */
for(i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++) {
skitem = sk_ASN1_VALUE_value(sk, i);
tder->data = p;
tder->length = ASN1_item_i2d(skitem, &p, item);
tder->field = skitem;
}
/* Now sort them */
qsort(derlst, sk_ASN1_VALUE_num(sk), sizeof(*derlst), der_cmp);
/* Output sorted DER encoding */
p = *out;
for(i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++) {
memcpy(p, tder->data, tder->length);
p += tder->length;
}
*out = p;
/* If do_sort is 2 then reorder the STACK */
if(do_sort == 2) {
for(i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++)
sk_ASN1_VALUE_set(sk, i, tder->field);
}
OPENSSL_free(derlst);
OPENSSL_free(tmpdat);
return 1;
}
static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass)
{
int len;
int utype;
int usetag;
utype = it->utype;
/* Get length of content octets and maybe find
* out the underlying type.
*/
len = asn1_ex_i2c(pval, NULL, &utype, it);
/* If SEQUENCE, SET or OTHER then header is
* included in pseudo content octets so don't
* include tag+length. We need to check here
* because the call to asn1_ex_i2c() could change
* utype.
*/
if((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) ||
(utype == V_ASN1_OTHER))
usetag = 0;
else usetag = 1;
/* -1 means omit type */
if(len == -1) return 0;
/* If not implicitly tagged get tag from underlying type */
if(tag == -1) tag = utype;
/* Output tag+length followed by content octets */
if(out) {
if(usetag) ASN1_put_object(out, 0, len, tag, aclass);
asn1_ex_i2c(pval, *out, &utype, it);
*out += len;
}
if(usetag) return ASN1_object_size(0, len, tag);
return len;
}
/* Produce content octets from a structure */
int asn1_ex_i2c(ASN1_VALUE **pval, unsigned char *cout, int *putype, const ASN1_ITEM *it)
{
ASN1_BOOLEAN *tbool = NULL;
ASN1_STRING *strtmp;
ASN1_OBJECT *otmp;
int utype;
unsigned char *cont, c;
int len;
const ASN1_PRIMITIVE_FUNCS *pf;
pf = it->funcs;
if(pf && pf->prim_i2c) return pf->prim_i2c(pval, cout, putype, it);
/* Should type be omitted? */
if((it->itype != ASN1_ITYPE_PRIMITIVE) || (it->utype != V_ASN1_BOOLEAN)) {
if(!*pval) return -1;
}
if(it->itype == ASN1_ITYPE_MSTRING) {
/* If MSTRING type set the underlying type */
strtmp = (ASN1_STRING *)*pval;
utype = strtmp->type;
*putype = utype;
} else if(it->utype == V_ASN1_ANY) {
/* If ANY set type and pointer to value */
ASN1_TYPE *typ;
typ = (ASN1_TYPE *)*pval;
utype = typ->type;
*putype = utype;
pval = (ASN1_VALUE **)&typ->value.ptr;
} else utype = *putype;
switch(utype) {
case V_ASN1_OBJECT:
otmp = (ASN1_OBJECT *)*pval;
cont = otmp->data;
len = otmp->length;
break;
case V_ASN1_NULL:
cont = NULL;
len = 0;
break;
case V_ASN1_BOOLEAN:
tbool = (ASN1_BOOLEAN *)pval;
if(*tbool == -1) return -1;
/* Default handling if value == size field then omit */
if(*tbool && (it->size > 0)) return -1;
if(!*tbool && !it->size) return -1;
c = (unsigned char)*tbool;
cont = &c;
len = 1;
break;
case V_ASN1_BIT_STRING:
return i2c_ASN1_BIT_STRING((ASN1_BIT_STRING *)*pval, cout ? &cout : NULL);
break;
case V_ASN1_INTEGER:
case V_ASN1_NEG_INTEGER:
case V_ASN1_ENUMERATED:
case V_ASN1_NEG_ENUMERATED:
/* These are all have the same content format
* as ASN1_INTEGER
*/
return i2c_ASN1_INTEGER((ASN1_INTEGER *)*pval, cout ? &cout : NULL);
break;
case V_ASN1_OCTET_STRING:
case V_ASN1_NUMERICSTRING:
case V_ASN1_PRINTABLESTRING:
case V_ASN1_T61STRING:
case V_ASN1_VIDEOTEXSTRING:
case V_ASN1_IA5STRING:
case V_ASN1_UTCTIME:
case V_ASN1_GENERALIZEDTIME:
case V_ASN1_GRAPHICSTRING:
case V_ASN1_VISIBLESTRING:
case V_ASN1_GENERALSTRING:
case V_ASN1_UNIVERSALSTRING:
case V_ASN1_BMPSTRING:
case V_ASN1_UTF8STRING:
case V_ASN1_SEQUENCE:
case V_ASN1_SET:
default:
/* All based on ASN1_STRING and handled the same */
strtmp = (ASN1_STRING *)*pval;
cont = strtmp->data;
len = strtmp->length;
break;
}
if(cout && len) memcpy(cout, cont, len);
return len;
}