cpython/Include/pyexpat.h
Bénédikt Tran 666112376d
gh-90949: expose Expat API to tune exponential expansion protections (#139368)
Expose the XML Expat 2.7.2 APIs to tune protections against
"billion laughs" [1] attacks.

The exposed APIs are available on Expat parsers, that is,
parsers created by `xml.parsers.expat.ParserCreate()`, as:

- `parser.SetBillionLaughsAttackProtectionActivationThreshold(threshold)`, and
- `parser.SetBillionLaughsAttackProtectionMaximumAmplification(max_factor)`.

This completes the work in f04bea44c3,
and improves the existing related documentation.

[1]: https://en.wikipedia.org/wiki/Billion_laughs_attack
2025-09-28 08:27:04 +00:00

67 lines
3.1 KiB
C

/* Stuff to export relevant 'expat' entry points from pyexpat to other
* parser modules, such as cElementTree. */
/* note: you must import expat.h before importing this module! */
#define PyExpat_CAPI_MAGIC "pyexpat.expat_CAPI 1.1"
#define PyExpat_CAPSULE_NAME "pyexpat.expat_CAPI"
struct PyExpat_CAPI
{
char* magic; /* set to PyExpat_CAPI_MAGIC */
int size; /* set to sizeof(struct PyExpat_CAPI) */
int MAJOR_VERSION;
int MINOR_VERSION;
int MICRO_VERSION;
/* pointers to selected expat functions. add new functions at
the end, if needed */
const XML_LChar * (*ErrorString)(enum XML_Error code);
enum XML_Error (*GetErrorCode)(XML_Parser parser);
XML_Size (*GetErrorColumnNumber)(XML_Parser parser);
XML_Size (*GetErrorLineNumber)(XML_Parser parser);
enum XML_Status (*Parse)(
XML_Parser parser, const char *s, int len, int isFinal);
XML_Parser (*ParserCreate_MM)(
const XML_Char *encoding, const XML_Memory_Handling_Suite *memsuite,
const XML_Char *namespaceSeparator);
void (*ParserFree)(XML_Parser parser);
void (*SetCharacterDataHandler)(
XML_Parser parser, XML_CharacterDataHandler handler);
void (*SetCommentHandler)(
XML_Parser parser, XML_CommentHandler handler);
void (*SetDefaultHandlerExpand)(
XML_Parser parser, XML_DefaultHandler handler);
void (*SetElementHandler)(
XML_Parser parser, XML_StartElementHandler start,
XML_EndElementHandler end);
void (*SetNamespaceDeclHandler)(
XML_Parser parser, XML_StartNamespaceDeclHandler start,
XML_EndNamespaceDeclHandler end);
void (*SetProcessingInstructionHandler)(
XML_Parser parser, XML_ProcessingInstructionHandler handler);
void (*SetUnknownEncodingHandler)(
XML_Parser parser, XML_UnknownEncodingHandler handler,
void *encodingHandlerData);
void (*SetUserData)(XML_Parser parser, void *userData);
void (*SetStartDoctypeDeclHandler)(XML_Parser parser,
XML_StartDoctypeDeclHandler start);
enum XML_Status (*SetEncoding)(XML_Parser parser, const XML_Char *encoding);
int (*DefaultUnknownEncodingHandler)(
void *encodingHandlerData, const XML_Char *name, XML_Encoding *info);
/* might be NULL for expat < 2.1.0 */
int (*SetHashSalt)(XML_Parser parser, unsigned long hash_salt);
/* might be NULL for expat < 2.6.0 */
XML_Bool (*SetReparseDeferralEnabled)(XML_Parser parser, XML_Bool enabled);
/* might be NULL for expat < 2.7.2 */
XML_Bool (*SetAllocTrackerActivationThreshold)(
XML_Parser parser, unsigned long long activationThresholdBytes);
XML_Bool (*SetAllocTrackerMaximumAmplification)(
XML_Parser parser, float maxAmplificationFactor);
/* might be NULL for expat < 2.4.0 */
XML_Bool (*SetBillionLaughsAttackProtectionActivationThreshold)(
XML_Parser parser, unsigned long long activationThresholdBytes);
XML_Bool (*SetBillionLaughsAttackProtectionMaximumAmplification)(
XML_Parser parser, float maxAmplificationFactor);
/* always add new stuff to the end! */
};