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/****************************************************************************
**
** Copyright (C) 2021 Intel Corporation
**
** Permission is hereby granted, free of charge, to any person obtaining a copy
** of this software and associated documentation files (the "Software"), to deal
** in the Software without restriction, including without limitation the rights
** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
** copies of the Software, and to permit persons to whom the Software is
** furnished to do so, subject to the following conditions:
**
** The above copyright notice and this permission notice shall be included in
** all copies or substantial portions of the Software.
**
** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
** THE SOFTWARE.
**
****************************************************************************/
#define _BSD_SOURCE 1
#define _DEFAULT_SOURCE 1
#ifndef __STDC_LIMIT_MACROS
# define __STDC_LIMIT_MACROS 1
#endif
#include "cbor.h"
#include "cborinternal_p.h"
#include "compilersupport_p.h"
#include "utf8_p.h"
#include <string.h>
#ifndef CBOR_NO_FLOATING_POINT
# include <float.h>
# include <math.h>
#endif
#ifndef CBOR_PARSER_MAX_RECURSIONS
# define CBOR_PARSER_MAX_RECURSIONS 1024
#endif
/**
* \addtogroup CborParsing
* @{
*/
/**
* \enum CborValidationFlags
* The CborValidationFlags enum contains flags that control the validation of a
* CBOR stream.
*
* \value CborValidateBasic Validates only the syntactic correctedness of the stream.
* \value CborValidateCanonical Validates that the stream is in canonical format, according to
* RFC 7049 section 3.9.
* \value CborValidateStrictMode Performs strict validation, according to RFC 7049 section 3.10.
* \value CborValidateStrictest Attempt to perform the strictest validation we know of.
*
* \value CborValidateShortestIntegrals (Canonical) Validate that integral numbers and lengths are
* enconded in their shortest form possible.
* \value CborValidateShortestFloatingPoint (Canonical) Validate that floating-point numbers are encoded
* in their shortest form possible.
* \value CborValidateShortestNumbers (Canonical) Validate both integral and floating-point numbers
* are in their shortest form possible.
* \value CborValidateNoIndeterminateLength (Canonical) Validate that no string, array or map uses
* indeterminate length encoding.
* \value CborValidateMapIsSorted (Canonical & Strict mode) Validate that map keys appear in
* sorted order.
* \value CborValidateMapKeysAreUnique (Strict mode) Validate that map keys are unique.
* \value CborValidateTagUse (Strict mode) Validate that known tags are used with the
* correct types. This does not validate that the content of
* those types is syntactically correct. For example, this
* option validates that tag 1 (DateTimeString) is used with
* a Text String, but it does not validate that the string is
* a valid date/time representation.
* \value CborValidateUtf8 (Strict mode) Validate that text strings are appropriately
* encoded in UTF-8.
* \value CborValidateMapKeysAreString Validate that all map keys are text strings.
* \value CborValidateNoUndefined Validate that no elements of type "undefined" are present.
* \value CborValidateNoTags Validate that no tags are used.
* \value CborValidateFiniteFloatingPoint Validate that all floating point numbers are finite (no NaN or
* infinities are allowed).
* \value CborValidateCompleteData Validate that the stream is complete and there is no more data
* in the buffer.
* \value CborValidateNoUnknownSimpleTypesSA Validate that all Standards Action simple types are registered
* with IANA.
* \value CborValidateNoUnknownSimpleTypes Validate that all simple types used are registered with IANA.
* \value CborValidateNoUnknownTagsSA Validate that all Standard Actions tags are registered with IANA.
* \value CborValidateNoUnknownTagsSR Validate that all Standard Actions and Specification Required tags
* are registered with IANA (see below for limitations).
* \value CborValidateNoUnkonwnTags Validate that all tags are registered with IANA
* (see below for limitations).
*
* \par Simple type registry
* The CBOR specification requires that registration for use of the first 19
* simple types must be done by way of Standards Action. The rest of the simple
* types only require a specification. The official list can be obtained from
* https://www.iana.org/assignments/cbor-simple-values/cbor-simple-values.xhtml.
*
* \par
* There are no registered simple types recognized by this release of TinyCBOR
* (beyond those defined by RFC 7049).
*
* \par Tag registry
* The CBOR specification requires that registration for use of the first 23
* tags must be done by way of Standards Action. The next up to tag 255 only
* require a specification. Finally, all other tags can be registered on a
* first-come-first-serve basis. The official list can be ontained from
* https://www.iana.org/assignments/cbor-tags/cbor-tags.xhtml.
*
* \par
* Given the variability of this list, TinyCBOR cannot recognize all tags
* registered with IANA. Instead, the implementation only recognizes tags
* that are backed by an RFC.
*
* \par
* These are the tags known to the current TinyCBOR release:
<table>
<tr>
<th>Tag</th>
<th>Data Item</th>
<th>Semantics</th>
</tr>
<tr>
<td>0</td>
<td>UTF-8 text string</td>
<td>Standard date/time string</td>
</tr>
<tr>
<td>1</td>
<td>integer</td>
<td>Epoch-based date/time</td>
</tr>
<tr>
<td>2</td>
<td>byte string</td>
<td>Positive bignum</td>
</tr>
<tr>
<td>3</td>
<td>byte string</td>
<td>Negative bignum</td>
</tr>
<tr>
<td>4</td>
<td>array</td>
<td>Decimal fraction</td>
</tr>
<tr>
<td>5</td>
<td>array</td>
<td>Bigfloat</td>
</tr>
<tr>
<td>16</td>
<td>array</td>
<td>COSE Single Recipient Encrypted Data Object (RFC 8152)</td>
</tr>
<tr>
<td>17</td>
<td>array</td>
<td>COSE Mac w/o Recipients Object (RFC 8152)</td>
</tr>
<tr>
<td>18</td>
<td>array</td>
<td>COSE Single Signer Data Object (RFC 8162)</td>
</tr>
<tr>
<td>21</td>
<td>byte string, array, map</td>
<td>Expected conversion to base64url encoding</td>
</tr>
<tr>
<td>22</td>
<td>byte string, array, map</td>
<td>Expected conversion to base64 encoding</td>
</tr>
<tr>
<td>23</td>
<td>byte string, array, map</td>
<td>Expected conversion to base16 encoding</td>
</tr>
<tr>
<td>24</td>
<td>byte string</td>
<td>Encoded CBOR data item</td>
</tr>
<tr>
<td>32</td>
<td>UTF-8 text string</td>
<td>URI</td>
</tr>
<tr>
<td>33</td>
<td>UTF-8 text string</td>
<td>base64url</td>
</tr>
<tr>
<td>34</td>
<td>UTF-8 text string</td>
<td>base64</td>
</tr>
<tr>
<td>35</td>
<td>UTF-8 text string</td>
<td>Regular expression</td>
</tr>
<tr>
<td>36</td>
<td>UTF-8 text string</td>
<td>MIME message</td>
</tr>
<tr>
<td>96</td>
<td>array</td>
<td>COSE Encrypted Data Object (RFC 8152)</td>
</tr>
<tr>
<td>97</td>
<td>array</td>
<td>COSE MACed Data Object (RFC 8152)</td>
</tr>
<tr>
<td>98</td>
<td>array</td>
<td>COSE Signed Data Object (RFC 8152)</td>
</tr>
<tr>
<td>55799</td>
<td>any</td>
<td>Self-describe CBOR</td>
</tr>
</table>
*/
struct KnownTagData { uint32_t tag; uint32_t types; };
static const struct KnownTagData knownTagData[] = {
{ 0, (uint32_t)CborTextStringType },
{ 1, (uint32_t)(CborIntegerType+1) },
{ 2, (uint32_t)CborByteStringType },
{ 3, (uint32_t)CborByteStringType },
{ 4, (uint32_t)CborArrayType },
{ 5, (uint32_t)CborArrayType },
{ 16, (uint32_t)CborArrayType },
{ 17, (uint32_t)CborArrayType },
{ 18, (uint32_t)CborArrayType },
{ 21, (uint32_t)CborByteStringType | ((uint32_t)CborArrayType << 8) | ((uint32_t)CborMapType << 16) },
{ 22, (uint32_t)CborByteStringType | ((uint32_t)CborArrayType << 8) | ((uint32_t)CborMapType << 16) },
{ 23, (uint32_t)CborByteStringType | ((uint32_t)CborArrayType << 8) | ((uint32_t)CborMapType << 16) },
{ 24, (uint32_t)CborByteStringType },
{ 32, (uint32_t)CborTextStringType },
{ 33, (uint32_t)CborTextStringType },
{ 34, (uint32_t)CborTextStringType },
{ 35, (uint32_t)CborTextStringType },
{ 36, (uint32_t)CborTextStringType },
{ 96, (uint32_t)CborArrayType },
{ 97, (uint32_t)CborArrayType },
{ 98, (uint32_t)CborArrayType },
{ 55799, 0U }
};
static CborError validate_value(CborValue *it, uint32_t flags, int recursionLeft);
static inline CborError validate_utf8_string(const void *ptr, size_t n)
{
const uint8_t *buffer = (const uint8_t *)ptr;
const uint8_t * const end = buffer + n;
while (buffer < end) {
uint32_t uc = get_utf8(&buffer, end);
if (uc == ~0U)
return CborErrorInvalidUtf8TextString;
}
return CborNoError;
}
static inline CborError validate_simple_type(uint8_t simple_type, uint32_t flags)
{
/* At current time, all known simple types are those from RFC 7049,
* which are parsed by the parser into different CBOR types.
* That means that if we've got here, the type is unknown */
if (simple_type < 32)
return (flags & CborValidateNoUnknownSimpleTypesSA) ? CborErrorUnknownSimpleType : CborNoError;
return (flags & CborValidateNoUnknownSimpleTypes) == CborValidateNoUnknownSimpleTypes ?
CborErrorUnknownSimpleType : CborNoError;
}
static inline CborError validate_number(const CborValue *it, CborType type, uint32_t flags)
{
CborError err = CborNoError;
size_t bytesUsed, bytesNeeded;
uint64_t value;
if ((flags & CborValidateShortestIntegrals) == 0)
return err;
if (type >= CborHalfFloatType && type <= CborDoubleType)
return err; /* checked elsewhere */
err = extract_number_checked(it, &value, &bytesUsed);
if (err)
return err;
bytesNeeded = 0;
if (value >= Value8Bit)
++bytesNeeded;
if (value > 0xffU)
++bytesNeeded;
if (value > 0xffffU)
bytesNeeded += 2;
if (value > 0xffffffffU)
bytesNeeded += 4;
if (bytesNeeded < bytesUsed)
return CborErrorOverlongEncoding;
return CborNoError;
}
static inline CborError validate_tag(CborValue *it, CborTag tag, uint32_t flags, int recursionLeft)
{
CborType type = cbor_value_get_type(it);
const size_t knownTagCount = sizeof(knownTagData) / sizeof(knownTagData[0]);
const struct KnownTagData *tagData = knownTagData;
const struct KnownTagData * const knownTagDataEnd = knownTagData + knownTagCount;
if (!recursionLeft)
return CborErrorNestingTooDeep;
if (flags & CborValidateNoTags)
return CborErrorExcludedType;
/* find the tag data, if any */
for ( ; tagData != knownTagDataEnd; ++tagData) {
if (tagData->tag < tag)
continue;
if (tagData->tag > tag)
tagData = NULL;
break;
}
if (tagData == knownTagDataEnd)
tagData = NULL;
if (flags & CborValidateNoUnknownTags && !tagData) {
/* tag not found */
if (flags & CborValidateNoUnknownTagsSA && tag < 24)
return CborErrorUnknownTag;
if ((flags & CborValidateNoUnknownTagsSR) == CborValidateNoUnknownTagsSR && tag < 256)
return CborErrorUnknownTag;
if ((flags & CborValidateNoUnknownTags) == CborValidateNoUnknownTags)
return CborErrorUnknownTag;
}
if (flags & CborValidateTagUse && tagData && tagData->types) {
uint32_t allowedTypes = tagData->types;
/* correct Integer so it's not zero */
if (type == CborIntegerType)
type = (CborType)(type + 1);
while (allowedTypes) {
if ((uint8_t)(allowedTypes & 0xff) == type)
break;
allowedTypes >>= 8;
}
if (!allowedTypes)
return CborErrorInappropriateTagForType;
}
return validate_value(it, flags, recursionLeft);
}
#ifndef CBOR_NO_FLOATING_POINT
static inline CborError validate_floating_point(CborValue *it, CborType type, uint32_t flags)
{
CborError err;
int r;
double val;
float valf;
uint16_t valf16 = 0x7c01; /* dummy value, an infinity */
if (type != CborDoubleType) {
if (type == CborFloatType) {
err = cbor_value_get_float(it, &valf);
val = valf;
} else {
# ifdef CBOR_NO_HALF_FLOAT_TYPE
(void)valf16;
return CborErrorUnsupportedType;
# else
err = cbor_value_get_half_float(it, &valf16);
val = decode_half(valf16);
# endif
}
} else {
err = cbor_value_get_double(it, &val);
}
cbor_assert(err == CborNoError); /* can't fail */
r = fpclassify(val);
if (r == FP_NAN || r == FP_INFINITE) {
if (flags & CborValidateFiniteFloatingPoint)
return CborErrorExcludedValue;
if (flags & CborValidateShortestFloatingPoint) {
if (type == CborDoubleType)
return CborErrorOverlongEncoding;
# ifndef CBOR_NO_HALF_FLOAT_TYPE
if (type == CborFloatType)
return CborErrorOverlongEncoding;
if (r == FP_NAN && valf16 != 0x7e00)
return CborErrorImproperValue;
if (r == FP_INFINITE && valf16 != 0x7c00 && valf16 != 0xfc00)
return CborErrorImproperValue;
# endif
}
}
if (flags & CborValidateShortestFloatingPoint && type > CborHalfFloatType) {
if (type == CborDoubleType) {
valf = (float)val;
if ((double)valf == val)
return CborErrorOverlongEncoding;
}
# ifndef CBOR_NO_HALF_FLOAT_TYPE
if (type == CborFloatType) {
valf16 = encode_half(valf);
if (valf == decode_half(valf16))
return CborErrorOverlongEncoding;
}
# endif
}
return CborNoError;
}
#endif
static CborError validate_container(CborValue *it, int containerType, uint32_t flags, int recursionLeft)
{
CborError err;
const uint8_t *previous = NULL;
const uint8_t *previous_end = NULL;
if (!recursionLeft)
return CborErrorNestingTooDeep;
while (!cbor_value_at_end(it)) {
const uint8_t *current = cbor_value_get_next_byte(it);
if (containerType == CborMapType) {
if (flags & CborValidateMapKeysAreString) {
CborType type = cbor_value_get_type(it);
if (type == CborTagType) {
/* skip the tags */
CborValue copy = *it;
err = cbor_value_skip_tag(&copy);
if (err)
return err;
type = cbor_value_get_type(&copy);
}
if (type != CborTextStringType)
return CborErrorMapKeyNotString;
}
}
err = validate_value(it, flags, recursionLeft);
if (err)
return err;
if (containerType != CborMapType)
continue;
if (flags & CborValidateMapIsSorted) {
if (it->parser->flags & CborParserFlag_ExternalSource)
return CborErrorUnimplementedValidation;
if (previous) {
size_t bytelen1 = (size_t)(previous_end - previous);
size_t bytelen2 = (size_t)(cbor_value_get_next_byte(it) - current);
int r = memcmp(previous, current, bytelen1 <= bytelen2 ? bytelen1 : bytelen2);
if (r == 0 && bytelen1 != bytelen2)
r = bytelen1 < bytelen2 ? -1 : +1;
if (r > 0)
return CborErrorMapNotSorted;
if (r == 0 && (flags & CborValidateMapKeysAreUnique) == CborValidateMapKeysAreUnique)
return CborErrorMapKeysNotUnique;
}
previous = current;
previous_end = cbor_value_get_next_byte(it);
}
/* map: that was the key, so get the value */
err = validate_value(it, flags, recursionLeft);
if (err)
return err;
}
return CborNoError;
}
static CborError validate_value(CborValue *it, uint32_t flags, int recursionLeft)
{
CborError err;
CborType type = cbor_value_get_type(it);
if (cbor_value_is_length_known(it)) {
err = validate_number(it, type, flags);
if (err)
return err;
} else {
if (flags & CborValidateNoIndeterminateLength)
return CborErrorUnknownLength;
}
switch (type) {
case CborArrayType:
case CborMapType: {
/* recursive type */
CborValue recursed;
err = cbor_value_enter_container(it, &recursed);
if (!err)
err = validate_container(&recursed, type, flags, recursionLeft - 1);
if (err) {
copy_current_position(it, &recursed);
return err;
}
err = cbor_value_leave_container(it, &recursed);
if (err)
return err;
return CborNoError;
}
case CborIntegerType: {
uint64_t val;
err = cbor_value_get_raw_integer(it, &val);
cbor_assert(err == CborNoError); /* can't fail */
break;
}
case CborByteStringType:
case CborTextStringType: {
size_t n = 0;
const void *ptr;
err = cbor_value_begin_string_iteration(it);
if (err)
return err;
while (1) {
CborValue next;
err = _cbor_value_get_string_chunk(it, &ptr, &n, &next);
if (!err) {
err = validate_number(it, type, flags);
if (err)
return err;
}
*it = next;
if (err == CborErrorNoMoreStringChunks)
return cbor_value_finish_string_iteration(it);
if (err)
return err;
if (type == CborTextStringType && flags & CborValidateUtf8) {
err = validate_utf8_string(ptr, n);
if (err)
return err;
}
}
return CborNoError;
}
case CborTagType: {
CborTag tag;
err = cbor_value_get_tag(it, &tag);
cbor_assert(err == CborNoError); /* can't fail */
err = cbor_value_advance_fixed(it);
if (err)
return err;
err = validate_tag(it, tag, flags, recursionLeft - 1);
if (err)
return err;
return CborNoError;
}
case CborSimpleType: {
uint8_t simple_type;
err = cbor_value_get_simple_type(it, &simple_type);
cbor_assert(err == CborNoError); /* can't fail */
err = validate_simple_type(simple_type, flags);
if (err)
return err;
break;
}
case CborNullType:
case CborBooleanType:
break;
case CborUndefinedType:
if (flags & CborValidateNoUndefined)
return CborErrorExcludedType;
break;
case CborHalfFloatType:
case CborFloatType:
case CborDoubleType: {
#ifdef CBOR_NO_FLOATING_POINT
return CborErrorUnsupportedType;
#else
err = validate_floating_point(it, type, flags);
if (err)
return err;
break;
#endif /* !CBOR_NO_FLOATING_POINT */
}
case CborInvalidType:
return CborErrorUnknownType;
}
err = cbor_value_advance_fixed(it);
return err;
}
/**
* Performs a full validation, controlled by the \a flags options, of the CBOR
* stream pointed by \a it and returns the error it found. If no error was
* found, it returns CborNoError and the application can iterate over the items
* with certainty that no errors will appear during parsing.
*
* If \a flags is CborValidateBasic, the result should be the same as
* cbor_value_validate_basic().
*
* This function has the same timing and memory requirements as
* cbor_value_advance() and cbor_value_validate_basic().
*
* \sa CborValidationFlags, cbor_value_validate_basic(), cbor_value_advance()
*/
CborError cbor_value_validate(const CborValue *it, uint32_t flags)
{
CborValue value = *it;
CborError err = validate_value(&value, flags, CBOR_PARSER_MAX_RECURSIONS);
if (err)
return err;
if (flags & CborValidateCompleteData && can_read_bytes(&value, 1))
return CborErrorGarbageAtEnd;
return CborNoError;
}
/**
* @}
*/