hdkv/yuzu
1
Fork 0
Code Issues Pull Requests Releases 1 Activity
caa0c2911b
yuzu/externals/libressl/crypto/asn1/tasn_dec.c
pineappleEA caa0c2911b early-access version 2698
2022-04-24 22:29:35 +02:00

1144 lines
28 KiB
C
Executable File
Raw Blame History

/* $OpenBSD: tasn_dec.c,v 1.49 2022/03/13 14:58:14 jsing Exp $ */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
* project 2000.
*/
/* ====================================================================
* Copyright (c) 2000-2005 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 <limits.h>
#include <stddef.h>
#include <string.h>
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/buffer.h>
#include <openssl/err.h>
#include <openssl/objects.h>
#include "asn1_locl.h"
#include "bytestring.h"
/* Constructed types with a recursive definition (such as can be found in PKCS7)
* could eventually exceed the stack given malicious input with excessive
* recursion. Therefore we limit the stack depth.
*/
#define ASN1_MAX_CONSTRUCTED_NEST 30
static int asn1_check_eoc(const unsigned char **in, long len);
static int asn1_find_end(const unsigned char **in, long len, char inf);
static int asn1_collect(CBB *cbb, const unsigned char **in, long len,
char inf, int tag, int aclass, int depth);
static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
char *inf, char *cst, const unsigned char **in, long len, int exptag,
int expclass, char opt, ASN1_TLC *ctx);
static int asn1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in,
long len, const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx,
int depth);
static int asn1_template_ex_d2i(ASN1_VALUE **pval, const unsigned char **in,
long len, const ASN1_TEMPLATE *tt, char opt, ASN1_TLC *ctx, int depth);
static int asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in,
long len, const ASN1_TEMPLATE *tt, char opt, ASN1_TLC *ctx, int depth);
static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in,
long len, const ASN1_ITEM *it, int tag, int aclass, char opt,
ASN1_TLC *ctx);
static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *content, int len,
int utype, const ASN1_ITEM *it);
static void
asn1_tlc_invalidate(ASN1_TLC *ctx)
{
if (ctx != NULL)
ctx->valid = 0;
}
ASN1_VALUE *
ASN1_item_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
const ASN1_ITEM *it)
{
ASN1_VALUE *ptmpval = NULL;
ASN1_TLC ctx;
asn1_tlc_invalidate(&ctx);
if (pval == NULL)
pval = &ptmpval;
if (asn1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &ctx, 0) <= 0)
return NULL;
return *pval;
}
int
ASN1_template_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
const ASN1_TEMPLATE *tt)
{
ASN1_TLC ctx;
asn1_tlc_invalidate(&ctx);
return asn1_template_ex_d2i(pval, in, len, tt, 0, &ctx, 0);
}
/* Decode an item, taking care of IMPLICIT tagging, if any.
* If 'opt' set and tag mismatch return -1 to handle OPTIONAL
*/
static int
asn1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx,
int depth)
{
const ASN1_TEMPLATE *tt, *errtt = NULL;
const ASN1_EXTERN_FUNCS *ef;
const ASN1_AUX *aux = it->funcs;
ASN1_aux_cb *asn1_cb = NULL;
const unsigned char *p = NULL, *q;
unsigned char oclass;
char seq_eoc, seq_nolen, cst, isopt;
long tmplen;
int i;
int otag;
int ret = 0;
ASN1_VALUE **pchptr;
int combine;
combine = aclass & ASN1_TFLG_COMBINE;
aclass &= ~ASN1_TFLG_COMBINE;
if (!pval)
return 0;
if (aux && aux->asn1_cb)
asn1_cb = aux->asn1_cb;
if (++depth > ASN1_MAX_CONSTRUCTED_NEST) {
ASN1error(ASN1_R_NESTED_TOO_DEEP);
goto err;
}
switch (it->itype) {
case ASN1_ITYPE_PRIMITIVE:
if (it->templates) {
/* tagging or OPTIONAL is currently illegal on an item
* template because the flags can't get passed down.
* In practice this isn't a problem: we include the
* relevant flags from the item template in the
* template itself.
*/
if ((tag != -1) || opt) {
ASN1error(ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
goto err;
}
return asn1_template_ex_d2i(pval, in, len,
it->templates, opt, ctx, depth);
}
return asn1_d2i_ex_primitive(pval, in, len, it,
tag, aclass, opt, ctx);
break;
case ASN1_ITYPE_MSTRING:
/*
* It never makes sense for multi-strings to have implicit
* tagging, so if tag != -1, then this looks like an error in
* the template.
*/
if (tag != -1) {
ASN1error(ASN1_R_BAD_TEMPLATE);
goto err;
}
p = *in;
/* Just read in tag and class */
ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
&p, len, -1, 0, 1, ctx);
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
goto err;
}
/* Must be UNIVERSAL class */
if (oclass != V_ASN1_UNIVERSAL) {
/* If OPTIONAL, assume this is OK */
if (opt)
return -1;
ASN1error(ASN1_R_MSTRING_NOT_UNIVERSAL);
goto err;
}
/* Check tag matches bit map */
if (!(ASN1_tag2bit(otag) & it->utype)) {
/* If OPTIONAL, assume this is OK */
if (opt)
return -1;
ASN1error(ASN1_R_MSTRING_WRONG_TAG);
goto err;
}
return asn1_d2i_ex_primitive(pval, in, len,
it, otag, 0, 0, ctx);
case ASN1_ITYPE_EXTERN:
/* Use new style d2i */
ef = it->funcs;
return ef->asn1_ex_d2i(pval, in, len,
it, tag, aclass, opt, ctx);
case ASN1_ITYPE_CHOICE:
/*
* It never makes sense for CHOICE types to have implicit
* tagging, so if tag != -1, then this looks like an error in
* the template.
*/
if (tag != -1) {
ASN1error(ASN1_R_BAD_TEMPLATE);
goto err;
}
if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
goto auxerr;
if (*pval) {
/* Free up and zero CHOICE value if initialised */
i = asn1_get_choice_selector(pval, it);
if ((i >= 0) && (i < it->tcount)) {
tt = it->templates + i;
pchptr = asn1_get_field_ptr(pval, tt);
ASN1_template_free(pchptr, tt);
asn1_set_choice_selector(pval, -1, it);
}
} else if (!ASN1_item_ex_new(pval, it)) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
goto err;
}
/* CHOICE type, try each possibility in turn */
p = *in;
for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
pchptr = asn1_get_field_ptr(pval, tt);
/* We mark field as OPTIONAL so its absence
* can be recognised.
*/
ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx,
depth);
/* If field not present, try the next one */
if (ret == -1)
continue;
/* If positive return, read OK, break loop */
if (ret > 0)
break;
/* Otherwise must be an ASN1 parsing error */
errtt = tt;
ASN1error(ERR_R_NESTED_ASN1_ERROR);
goto err;
}
/* Did we fall off the end without reading anything? */
if (i == it->tcount) {
/* If OPTIONAL, this is OK */
if (opt) {
/* Free and zero it */
ASN1_item_ex_free(pval, it);
return -1;
}
ASN1error(ASN1_R_NO_MATCHING_CHOICE_TYPE);
goto err;
}
asn1_set_choice_selector(pval, i, it);
*in = p;
if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
goto auxerr;
return 1;
case ASN1_ITYPE_NDEF_SEQUENCE:
case ASN1_ITYPE_SEQUENCE:
p = *in;
tmplen = len;
/* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
if (tag == -1) {
tag = V_ASN1_SEQUENCE;
aclass = V_ASN1_UNIVERSAL;
}
/* Get SEQUENCE length and update len, p */
ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
&p, len, tag, aclass, opt, ctx);
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
goto err;
} else if (ret == -1)
return -1;
if (aux && (aux->flags & ASN1_AFLG_BROKEN)) {
len = tmplen - (p - *in);
seq_nolen = 1;
}
/* If indefinite we don't do a length check */
else
seq_nolen = seq_eoc;
if (!cst) {
ASN1error(ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
goto err;
}
if (!*pval && !ASN1_item_ex_new(pval, it)) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
goto err;
}
if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
goto auxerr;
/* Free up and zero any ADB found */
for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
if (tt->flags & ASN1_TFLG_ADB_MASK) {
const ASN1_TEMPLATE *seqtt;
ASN1_VALUE **pseqval;
seqtt = asn1_do_adb(pval, tt, 1);
if (!seqtt)
goto err;
pseqval = asn1_get_field_ptr(pval, seqtt);
ASN1_template_free(pseqval, seqtt);
}
}
/* Get each field entry */
for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
const ASN1_TEMPLATE *seqtt;
ASN1_VALUE **pseqval;
seqtt = asn1_do_adb(pval, tt, 1);
if (!seqtt)
goto err;
pseqval = asn1_get_field_ptr(pval, seqtt);
/* Have we ran out of data? */
if (!len)
break;
q = p;
if (asn1_check_eoc(&p, len)) {
if (!seq_eoc) {
ASN1error(ASN1_R_UNEXPECTED_EOC);
goto err;
}
len -= p - q;
seq_eoc = 0;
q = p;
break;
}
/* This determines the OPTIONAL flag value. The field
* cannot be omitted if it is the last of a SEQUENCE
* and there is still data to be read. This isn't
* strictly necessary but it increases efficiency in
* some cases.
*/
if (i == (it->tcount - 1))
isopt = 0;
else
isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
/* attempt to read in field, allowing each to be
* OPTIONAL */
ret = asn1_template_ex_d2i(pseqval, &p, len,
seqtt, isopt, ctx, depth);
if (!ret) {
errtt = seqtt;
goto err;
} else if (ret == -1) {
/* OPTIONAL component absent.
* Free and zero the field.
*/
ASN1_template_free(pseqval, seqtt);
continue;
}
/* Update length */
len -= p - q;
}
/* Check for EOC if expecting one */
if (seq_eoc && !asn1_check_eoc(&p, len)) {
ASN1error(ASN1_R_MISSING_EOC);
goto err;
}
/* Check all data read */
if (!seq_nolen && len) {
ASN1error(ASN1_R_SEQUENCE_LENGTH_MISMATCH);
goto err;
}
/* If we get here we've got no more data in the SEQUENCE,
* however we may not have read all fields so check all
* remaining are OPTIONAL and clear any that are.
*/
for (; i < it->tcount; tt++, i++) {
const ASN1_TEMPLATE *seqtt;
seqtt = asn1_do_adb(pval, tt, 1);
if (!seqtt)
goto err;
if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
ASN1_VALUE **pseqval;
pseqval = asn1_get_field_ptr(pval, seqtt);
ASN1_template_free(pseqval, seqtt);
} else {
errtt = seqtt;
ASN1error(ASN1_R_FIELD_MISSING);
goto err;
}
}
/* Save encoding */
if (!asn1_enc_save(pval, *in, p - *in, it)) {
ASN1error(ERR_R_MALLOC_FAILURE);
goto auxerr;
}
*in = p;
if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
goto auxerr;
return 1;
default:
return 0;
}
auxerr:
ASN1error(ASN1_R_AUX_ERROR);
err:
if (combine == 0)
ASN1_item_ex_free(pval, it);
if (errtt)
ERR_asprintf_error_data("Field=%s, Type=%s", errtt->field_name,
it->sname);
else
ERR_asprintf_error_data("Type=%s", it->sname);
return 0;
}
int
ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx)
{
return asn1_item_ex_d2i(pval, in, len, it, tag, aclass, opt, ctx, 0);
}
/* Templates are handled with two separate functions.
* One handles any EXPLICIT tag and the other handles the rest.
*/
static int
asn1_template_ex_d2i(ASN1_VALUE **val, const unsigned char **in, long inlen,
const ASN1_TEMPLATE *tt, char opt, ASN1_TLC *ctx, int depth)
{
int flags, aclass;
int ret;
long len;
const unsigned char *p, *q;
char exp_eoc;
if (!val)
return 0;
flags = tt->flags;
aclass = flags & ASN1_TFLG_TAG_CLASS;
p = *in;
/* Check if EXPLICIT tag expected */
if (flags & ASN1_TFLG_EXPTAG) {
char cst;
/* Need to work out amount of data available to the inner
* content and where it starts: so read in EXPLICIT header to
* get the info.
*/
ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
&p, inlen, tt->tag, aclass, opt, ctx);
q = p;
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
return 0;
} else if (ret == -1)
return -1;
if (!cst) {
ASN1error(ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
return 0;
}
/* We've found the field so it can't be OPTIONAL now */
ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx, depth);
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
return 0;
}
/* We read the field in OK so update length */
len -= p - q;
if (exp_eoc) {
/* If NDEF we must have an EOC here */
if (!asn1_check_eoc(&p, len)) {
ASN1error(ASN1_R_MISSING_EOC);
goto err;
}
} else {
/* Otherwise we must hit the EXPLICIT tag end or its
* an error */
if (len) {
ASN1error(ASN1_R_EXPLICIT_LENGTH_MISMATCH);
goto err;
}
}
} else
return asn1_template_noexp_d2i(val, in, inlen, tt, opt, ctx,
depth);
*in = p;
return 1;
err:
ASN1_template_free(val, tt);
return 0;
}
static int
asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in, long len,
const ASN1_TEMPLATE *tt, char opt, ASN1_TLC *ctx, int depth)
{
int flags, aclass;
int ret;
const unsigned char *p, *q;
if (!val)
return 0;
flags = tt->flags;
aclass = flags & ASN1_TFLG_TAG_CLASS;
p = *in;
q = p;
if (flags & ASN1_TFLG_SK_MASK) {
/* SET OF, SEQUENCE OF */
int sktag, skaclass;
char sk_eoc;
/* First work out expected inner tag value */
if (flags & ASN1_TFLG_IMPTAG) {
sktag = tt->tag;
skaclass = aclass;
} else {
skaclass = V_ASN1_UNIVERSAL;
if (flags & ASN1_TFLG_SET_OF)
sktag = V_ASN1_SET;
else
sktag = V_ASN1_SEQUENCE;
}
/* Get the tag */
ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
&p, len, sktag, skaclass, opt, ctx);
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
return 0;
} else if (ret == -1)
return -1;
if (!*val)
*val = (ASN1_VALUE *)sk_new_null();
else {
/* We've got a valid STACK: free up any items present */
STACK_OF(ASN1_VALUE) *sktmp =
(STACK_OF(ASN1_VALUE) *)*val;
ASN1_VALUE *vtmp;
while (sk_ASN1_VALUE_num(sktmp) > 0) {
vtmp = sk_ASN1_VALUE_pop(sktmp);
ASN1_item_ex_free(&vtmp,
tt->item);
}
}
if (!*val) {
ASN1error(ERR_R_MALLOC_FAILURE);
goto err;
}
/* Read as many items as we can */
while (len > 0) {
ASN1_VALUE *skfield;
q = p;
/* See if EOC found */
if (asn1_check_eoc(&p, len)) {
if (!sk_eoc) {
ASN1error(ASN1_R_UNEXPECTED_EOC);
goto err;
}
len -= p - q;
sk_eoc = 0;
break;
}
skfield = NULL;
if (!asn1_item_ex_d2i(&skfield, &p, len,
tt->item, -1, 0, 0, ctx, depth)) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
goto err;
}
len -= p - q;
if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val,
skfield)) {
ASN1error(ERR_R_MALLOC_FAILURE);
goto err;
}
}
if (sk_eoc) {
ASN1error(ASN1_R_MISSING_EOC);
goto err;
}
} else if (flags & ASN1_TFLG_IMPTAG) {
/* IMPLICIT tagging */
ret = asn1_item_ex_d2i(val, &p, len,
tt->item, tt->tag, aclass, opt, ctx, depth);
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
goto err;
} else if (ret == -1)
return -1;
} else {
/* Nothing special */
ret = asn1_item_ex_d2i(val, &p, len, tt->item,
-1, tt->flags & ASN1_TFLG_COMBINE, opt, ctx, depth);
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
goto err;
} else if (ret == -1)
return -1;
}
*in = p;
return 1;
err:
ASN1_template_free(val, tt);
return 0;
}
static int
asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in, long inlen,
const ASN1_ITEM *it, int tag, int aclass, char opt, ASN1_TLC *ctx)
{
int ret = 0, utype;
long plen;
char cst, inf;
const unsigned char *p;
const unsigned char *content = NULL;
uint8_t *data = NULL;
size_t data_len = 0;
CBB cbb;
long len;
memset(&cbb, 0, sizeof(cbb));
if (!pval) {
ASN1error(ASN1_R_ILLEGAL_NULL);
return 0; /* Should never happen */
}
if (it->itype == ASN1_ITYPE_MSTRING) {
utype = tag;
tag = -1;
} else
utype = it->utype;
if (utype == V_ASN1_ANY) {
/* If type is ANY need to figure out type from tag */
unsigned char oclass;
if (tag >= 0) {
ASN1error(ASN1_R_ILLEGAL_TAGGED_ANY);
return 0;
}
if (opt) {
ASN1error(ASN1_R_ILLEGAL_OPTIONAL_ANY);
return 0;
}
p = *in;
ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
&p, inlen, -1, 0, 0, ctx);
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
return 0;
}
if (oclass != V_ASN1_UNIVERSAL)
utype = V_ASN1_OTHER;
}
if (tag == -1) {
tag = utype;
aclass = V_ASN1_UNIVERSAL;
}
p = *in;
/* Check header */
ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
&p, inlen, tag, aclass, opt, ctx);
if (!ret) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
return 0;
} else if (ret == -1)
return -1;
ret = 0;
/* SEQUENCE, SET and "OTHER" are left in encoded form */
if ((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) ||
(utype == V_ASN1_OTHER)) {
/* Clear context cache for type OTHER because the auto clear
* when we have a exact match wont work
*/
if (utype == V_ASN1_OTHER) {
asn1_tlc_invalidate(ctx);
} else if (!cst) {
/* SEQUENCE and SET must be constructed */
ASN1error(ASN1_R_TYPE_NOT_CONSTRUCTED);
return 0;
}
content = *in;
/* If indefinite length constructed find the real end */
if (inf) {
if (!asn1_find_end(&p, plen, inf))
goto err;
len = p - content;
} else {
len = p - content + plen;
p += plen;
}
} else if (cst) {
/*
* Should really check the internal tags are correct but
* some things may get this wrong. The relevant specs
* say that constructed string types should be OCTET STRINGs
* internally irrespective of the type. So instead just check
* for UNIVERSAL class and ignore the tag.
*/
if (!CBB_init(&cbb, 0))
goto err;
if (!asn1_collect(&cbb, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
goto err;
if (!CBB_finish(&cbb, &data, &data_len))
goto err;
if (data_len > LONG_MAX)
goto err;
content = data;
len = data_len;
} else {
content = p;
len = plen;
p += plen;
}
/* We now have content length and type: translate into a structure */
if (!asn1_ex_c2i(pval, content, len, utype, it))
goto err;
*in = p;
ret = 1;
err:
CBB_cleanup(&cbb);
freezero(data, data_len);
return ret;
}
/* Translate ASN1 content octets into a structure */
static int
asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *content, int len, int utype,
const ASN1_ITEM *it)
{
ASN1_VALUE **opval = NULL;
ASN1_STRING *stmp;
ASN1_TYPE *typ = NULL;
ASN1_INTEGER **tint;
int ret = 0;
if (it->funcs != NULL) {
const ASN1_PRIMITIVE_FUNCS *pf = it->funcs;
char free_content = 0;
if (pf->prim_c2i == NULL)
return 0;
return pf->prim_c2i(pval, content, len, utype, &free_content, it);
}
/* If ANY type clear type and set pointer to internal value */
if (it->utype == V_ASN1_ANY) {
if (!*pval) {
typ = ASN1_TYPE_new();
if (typ == NULL)
goto err;
*pval = (ASN1_VALUE *)typ;
} else
typ = (ASN1_TYPE *)*pval;
if (utype != typ->type)
ASN1_TYPE_set(typ, utype, NULL);
opval = pval;
pval = &typ->value.asn1_value;
}
switch (utype) {
case V_ASN1_OBJECT:
if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &content, len))
goto err;
break;
case V_ASN1_NULL:
if (len) {
ASN1error(ASN1_R_NULL_IS_WRONG_LENGTH);
goto err;
}
*pval = (ASN1_VALUE *)1;
break;
case V_ASN1_BOOLEAN:
if (len != 1) {
ASN1error(ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
goto err;
} else {
ASN1_BOOLEAN *tbool;
tbool = (ASN1_BOOLEAN *)pval;
*tbool = *content;
}
break;
case V_ASN1_BIT_STRING:
if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &content, len))
goto err;
break;
case V_ASN1_INTEGER:
case V_ASN1_ENUMERATED:
tint = (ASN1_INTEGER **)pval;
if (!c2i_ASN1_INTEGER(tint, &content, len))
goto err;
/* Fixup type to match the expected form */
(*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
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_OTHER:
case V_ASN1_SET:
case V_ASN1_SEQUENCE:
default:
if (utype == V_ASN1_BMPSTRING && (len & 1)) {
ASN1error(ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
goto err;
}
if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
ASN1error(ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
goto err;
}
/* All based on ASN1_STRING and handled the same way. */
if (*pval == NULL) {
if ((stmp = ASN1_STRING_type_new(utype)) == NULL) {
ASN1error(ERR_R_MALLOC_FAILURE);
goto err;
}
*pval = (ASN1_VALUE *)stmp;
} else {
stmp = (ASN1_STRING *)*pval;
stmp->type = utype;
}
if (!ASN1_STRING_set(stmp, content, len)) {
ASN1_STRING_free(stmp);
*pval = NULL;
goto err;
}
break;
}
/* If ASN1_ANY and NULL type fix up value */
if (typ && (utype == V_ASN1_NULL))
typ->value.ptr = NULL;
ret = 1;
err:
if (!ret) {
ASN1_TYPE_free(typ);
if (opval)
*opval = NULL;
}
return ret;
}
/* This function finds the end of an ASN1 structure when passed its maximum
* length, whether it is indefinite length and a pointer to the content.
* This is more efficient than calling asn1_collect because it does not
* recurse on each indefinite length header.
*/
static int
asn1_find_end(const unsigned char **in, long len, char inf)
{
int expected_eoc;
long plen;
const unsigned char *p = *in, *q;
/* If not indefinite length constructed just add length */
if (inf == 0) {
*in += len;
return 1;
}
expected_eoc = 1;
/* Indefinite length constructed form. Find the end when enough EOCs
* are found. If more indefinite length constructed headers
* are encountered increment the expected eoc count otherwise just
* skip to the end of the data.
*/
while (len > 0) {
if (asn1_check_eoc(&p, len)) {
expected_eoc--;
if (expected_eoc == 0)
break;
len -= 2;
continue;
}
q = p;
/* Just read in a header: only care about the length */
if (!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
-1, 0, 0, NULL)) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
return 0;
}
if (inf)
expected_eoc++;
else
p += plen;
len -= p - q;
}
if (expected_eoc) {
ASN1error(ASN1_R_MISSING_EOC);
return 0;
}
*in = p;
return 1;
}
/* This function collects the asn1 data from a constructred string
* type into a buffer. The values of 'in' and 'len' should refer
* to the contents of the constructed type and 'inf' should be set
* if it is indefinite length.
*/
#ifndef ASN1_MAX_STRING_NEST
/* This determines how many levels of recursion are permitted in ASN1
* string types. If it is not limited stack overflows can occur. If set
* to zero no recursion is allowed at all. Although zero should be adequate
* examples exist that require a value of 1. So 5 should be more than enough.
*/
#define ASN1_MAX_STRING_NEST 5
#endif
static int
asn1_collect(CBB *cbb, const unsigned char **in, long len, char inf,
int tag, int aclass, int depth)
{
const unsigned char *p, *q;
long plen;
char cst, ininf;
if (depth > ASN1_MAX_STRING_NEST) {
ASN1error(ASN1_R_NESTED_ASN1_STRING);
return 0;
}
p = *in;
inf &= 1;
while (len > 0) {
q = p;
/* Check for EOC */
if (asn1_check_eoc(&p, len)) {
/* EOC is illegal outside indefinite length
* constructed form */
if (!inf) {
ASN1error(ASN1_R_UNEXPECTED_EOC);
return 0;
}
inf = 0;
break;
}
if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
len, tag, aclass, 0, NULL)) {
ASN1error(ERR_R_NESTED_ASN1_ERROR);
return 0;
}
/* If indefinite length constructed update max length */
if (cst) {
if (!asn1_collect(cbb, &p, plen, ininf, tag, aclass,
depth + 1))
return 0;
} else if (plen > 0) {
if (!CBB_add_bytes(cbb, p, plen))
return 0;
p += plen;
}
len -= p - q;
}
if (inf) {
ASN1error(ASN1_R_MISSING_EOC);
return 0;
}
*in = p;
return 1;
}
/* Check for ASN1 EOC and swallow it if found */
static int
asn1_check_eoc(const unsigned char **in, long len)
{
const unsigned char *p;
if (len < 2)
return 0;
p = *in;
if (!p[0] && !p[1]) {
*in += 2;
return 1;
}
return 0;
}
/* Check an ASN1 tag and length: a bit like ASN1_get_object
* but it sets the length for indefinite length constructed
* form, we don't know the exact length but we can set an
* upper bound to the amount of data available minus the
* header length just read.
*/
static int
asn1_check_tlen(long *olen, int *otag, unsigned char *oclass, char *inf,
char *cst, const unsigned char **in, long len, int exptag, int expclass,
char opt, ASN1_TLC *ctx)
{
int i;
int ptag, pclass;
long plen;
const unsigned char *p, *q;
p = *in;
q = p;
if (ctx && ctx->valid) {
i = ctx->ret;
plen = ctx->plen;
pclass = ctx->pclass;
ptag = ctx->ptag;
p += ctx->hdrlen;
} else {
i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
if (ctx) {
ctx->ret = i;
ctx->plen = plen;
ctx->pclass = pclass;
ctx->ptag = ptag;
ctx->hdrlen = p - q;
ctx->valid = 1;
/* If definite length, and no error, length +
* header can't exceed total amount of data available.
*/
if (!(i & 0x81) && ((plen + ctx->hdrlen) > len)) {
ASN1error(ASN1_R_TOO_LONG);
asn1_tlc_invalidate(ctx);
return 0;
}
}
}
if (i & 0x80) {
ASN1error(ASN1_R_BAD_OBJECT_HEADER);
asn1_tlc_invalidate(ctx);
return 0;
}
if (exptag >= 0) {
if ((exptag != ptag) || (expclass != pclass)) {
/* If type is OPTIONAL, not an error:
* indicate missing type.
*/
if (opt)
return -1;
asn1_tlc_invalidate(ctx);
ASN1error(ASN1_R_WRONG_TAG);
return 0;
}
/* We have a tag and class match:
* assume we are going to do something with it */
asn1_tlc_invalidate(ctx);
}
if (i & 1)
plen = len - (p - q);
if (inf)
*inf = i & 1;
if (cst)
*cst = i & V_ASN1_CONSTRUCTED;
if (olen)
*olen = plen;
if (oclass)
*oclass = pclass;
if (otag)
*otag = ptag;
*in = p;
return 1;
}
Reference in New Issue View Git Blame Copy Permalink