Add the API to do more in-depth validation
This implements barely the canonical validation. Implemented features:
- CborValidateShortestFloatingPoint
- CborValidateNoIndeterminateLength
- CborValidateNoUndefined
- CborValidateNoTags
- CborValidateCompleteData
- CborValidateNoUnknownSimpleTypesSA
- CborValidateNoUnknownSimpleTypes
Signed-off-by: Thiago Macieira <thiago.macieira@intel.com>
diff --git a/src/cborvalidation.c b/src/cborvalidation.c
new file mode 100644
index 0000000..6b19c58
--- /dev/null
+++ b/src/cborvalidation.c
@@ -0,0 +1,375 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 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 <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 syntax 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 integrals 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.
+ * \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:
+[will be added in the next commit]
+ */
+
+static CborError validate_value(CborValue *it, int flags, int recursionLeft);
+
+static inline CborError validate_simple_type(uint8_t simple_type, int 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_tag(CborValue *it, CborTag tag, int flags, int recursionLeft)
+{
+ CborType type = cbor_value_get_type(it);
+ if (!recursionLeft)
+ return CborErrorNestingTooDeep;
+
+ if (flags & CborValidateNoTags)
+ return CborErrorExcludedType;
+ if (flags & CborValidateNoUnknownTags) {
+ if (tag > 255 && (flags & CborValidateNoUnknownTagsSR) == 0)
+ return CborErrorUnknownTag;
+ if (flags & CborValidateNoUnknownTagsSR) {
+ if (tag > 23 && (flags & CborValidateNoUnknownTagsSA) == 0)
+ return CborErrorUnknownTag;
+ if (flags & CborValidateNoUnknownTagsSA)
+ return CborErrorUnknownTag;
+ }
+ }
+
+ return validate_value(it, flags, recursionLeft);
+}
+
+#ifndef CBOR_NO_FLOATING_POINT
+static inline CborError validate_floating_point(CborValue *it, CborType type, int flags)
+{
+ CborError err;
+ double val;
+ float valf;
+ uint16_t valf16;
+
+ if (type != CborDoubleType) {
+ if (type == CborFloatType) {
+ err = cbor_value_get_float(it, &valf);
+ val = valf;
+ } else {
+# ifdef CBOR_NO_HALF_FLOAT_TYPE
+ (void)val16;
+ 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 */
+
+ int 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, int flags, int recursionLeft)
+{
+ CborError err;
+ if (!recursionLeft)
+ return CborErrorNestingTooDeep;
+
+ while (!cbor_value_at_end(it)) {
+ err = validate_value(it, flags, recursionLeft);
+ if (err)
+ return err;
+
+ if (containerType == CborArrayType)
+ continue;
+
+ /* map: that was the key, so get he value */
+ err = validate_value(it, flags, recursionLeft);
+ if (err)
+ return err;
+ }
+ return CborNoError;
+}
+
+static CborError validate_value(CborValue *it, int flags, int recursionLeft)
+{
+ CborError err;
+ if (flags & CborValidateNoIndeterminateLength) {
+ if (!cbor_value_is_length_known(it))
+ return CborErrorUnknownLength;
+ }
+
+ CborType type = cbor_value_get_type(it);
+ 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) {
+ it->ptr = recursed.ptr;
+ 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;
+
+ while (1) {
+ err = _cbor_value_get_string_chunk(it, &ptr, &n, it);
+ if (err)
+ return err;
+ if (!ptr)
+ break;
+ }
+
+ 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 other 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, int flags)
+{
+ CborValue value = *it;
+ CborError err = validate_value(&value, flags, CBOR_PARSER_MAX_RECURSIONS);
+ if (err)
+ return err;
+ if (flags & CborValidateCompleteData && it->ptr != it->parser->end)
+ return CborErrorGarbageAtEnd;
+ return CborNoError;
+}
+
+/**
+ * @}
+ */