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2649 lines (2270 loc) · 72.1 KB
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/* Module that wraps all OpenSSL hash algorithms */
/*
* Copyright (C) 2005-2010 Gregory P. Smith (greg@krypto.org)
* Licensed to PSF under a Contributor Agreement.
*
* Derived from a skeleton of shamodule.c containing work performed by:
*
* Andrew Kuchling (amk@amk.ca)
* Greg Stein (gstein@lyra.org)
*
*/
/* Don't warn about deprecated functions, */
#ifndef OPENSSL_API_COMPAT
// 0x10101000L == 1.1.1, 30000 == 3.0.0
#define OPENSSL_API_COMPAT 0x10101000L
#endif
#define OPENSSL_NO_DEPRECATED 1
#ifndef Py_BUILD_CORE_BUILTIN
# define Py_BUILD_CORE_MODULE 1
#endif
#include "Python.h"
#include "pycore_hashtable.h"
#include "pycore_strhex.h" // _Py_strhex()
#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_LOAD_PTR_RELAXED
#include "hashlib.h"
/* EVP is the preferred interface to hashing in OpenSSL */
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/crypto.h> // FIPS_mode()
/* We use the object interface to discover what hashes OpenSSL supports. */
#include <openssl/objects.h>
#include <openssl/err.h>
#include <stdbool.h>
#if OPENSSL_VERSION_NUMBER >= 0x30000000L
# define Py_HAS_OPENSSL3_SUPPORT
#endif
#ifndef OPENSSL_THREADS
# error "OPENSSL_THREADS is not defined, Python requires thread-safe OpenSSL"
#endif
#define MUNCH_SIZE INT_MAX
#if defined(NID_sha3_224) && defined(NID_sha3_256) && defined(NID_sha3_384) && defined(NID_sha3_512)
#define PY_OPENSSL_HAS_SHA3 1
#endif
#if defined(NID_shake128) || defined(NID_shake256)
#define PY_OPENSSL_HAS_SHAKE 1
#endif
#if defined(NID_blake2s256) || defined(NID_blake2b512)
#define PY_OPENSSL_HAS_BLAKE2 1
#endif
#ifdef Py_HAS_OPENSSL3_SUPPORT
#define PY_EVP_MD EVP_MD
#define PY_EVP_MD_fetch(algorithm, properties) EVP_MD_fetch(NULL, algorithm, properties)
#define PY_EVP_MD_up_ref(md) EVP_MD_up_ref(md)
#define PY_EVP_MD_free(md) EVP_MD_free(md)
#define PY_EVP_MD_CTX_md(CTX) EVP_MD_CTX_get0_md(CTX)
#else
#define PY_EVP_MD const EVP_MD
#define PY_EVP_MD_fetch(algorithm, properties) EVP_get_digestbyname(algorithm)
#define PY_EVP_MD_up_ref(md) do {} while(0)
#define PY_EVP_MD_free(md) do {} while(0)
#define PY_EVP_MD_CTX_md(CTX) EVP_MD_CTX_md(CTX)
#endif
/*
* Return 1 if *md* is an extendable-output Function (XOF) and 0 otherwise.
* SHAKE128 and SHAKE256 are XOF functions but not BLAKE2B algorithms.
*
* This is a backport of the EVP_MD_xof() helper added in OpenSSL 3.4.
*/
static inline int
PY_EVP_MD_xof(PY_EVP_MD *md)
{
return md != NULL && ((EVP_MD_flags(md) & EVP_MD_FLAG_XOF) != 0);
}
/* hash alias map and fast lookup
*
* Map between Python's preferred names and OpenSSL internal names. Maintain
* cache of fetched EVP MD objects. The EVP_get_digestbyname() and
* EVP_MD_fetch() API calls have a performance impact.
*
* The py_hashentry_t items are stored in a _Py_hashtable_t with py_name and
* py_alias as keys.
*/
typedef enum Py_hash_type {
Py_ht_evp, // usedforsecurity=True / default
Py_ht_evp_nosecurity, // usedforsecurity=False
Py_ht_mac, // HMAC
Py_ht_pbkdf2, // PKBDF2
} Py_hash_type;
typedef struct {
const char *py_name;
const char *py_alias;
const char *ossl_name;
int ossl_nid;
int refcnt;
PY_EVP_MD *evp;
PY_EVP_MD *evp_nosecurity;
} py_hashentry_t;
// Fundamental to TLS, assumed always present in any libcrypto:
#define Py_hash_md5 "md5"
#define Py_hash_sha1 "sha1"
#define Py_hash_sha224 "sha224"
#define Py_hash_sha256 "sha256"
#define Py_hash_sha384 "sha384"
#define Py_hash_sha512 "sha512"
// Not all OpenSSL-like libcrypto libraries provide these:
#if defined(NID_sha512_224)
# define Py_hash_sha512_224 "sha512_224"
#endif
#if defined(NID_sha512_256)
# define Py_hash_sha512_256 "sha512_256"
#endif
#if defined(NID_sha3_224)
# define Py_hash_sha3_224 "sha3_224"
#endif
#if defined(NID_sha3_256)
# define Py_hash_sha3_256 "sha3_256"
#endif
#if defined(NID_sha3_384)
# define Py_hash_sha3_384 "sha3_384"
#endif
#if defined(NID_sha3_512)
# define Py_hash_sha3_512 "sha3_512"
#endif
#if defined(NID_shake128)
# define Py_hash_shake_128 "shake_128"
#endif
#if defined(NID_shake256)
# define Py_hash_shake_256 "shake_256"
#endif
#if defined(NID_blake2s256)
# define Py_hash_blake2s "blake2s"
#endif
#if defined(NID_blake2b512)
# define Py_hash_blake2b "blake2b"
#endif
#define PY_HASH_ENTRY(py_name, py_alias, ossl_name, ossl_nid) \
{py_name, py_alias, ossl_name, ossl_nid, 0, NULL, NULL}
static const py_hashentry_t py_hashes[] = {
/* md5 */
PY_HASH_ENTRY(Py_hash_md5, "MD5", SN_md5, NID_md5),
/* sha1 */
PY_HASH_ENTRY(Py_hash_sha1, "SHA1", SN_sha1, NID_sha1),
/* sha2 family */
PY_HASH_ENTRY(Py_hash_sha224, "SHA224", SN_sha224, NID_sha224),
PY_HASH_ENTRY(Py_hash_sha256, "SHA256", SN_sha256, NID_sha256),
PY_HASH_ENTRY(Py_hash_sha384, "SHA384", SN_sha384, NID_sha384),
PY_HASH_ENTRY(Py_hash_sha512, "SHA512", SN_sha512, NID_sha512),
/* truncated sha2 */
#ifdef Py_hash_sha512_224
PY_HASH_ENTRY(Py_hash_sha512_224, "SHA512_224", SN_sha512_224, NID_sha512_224),
#endif
#ifdef Py_hash_sha512_256
PY_HASH_ENTRY(Py_hash_sha512_256, "SHA512_256", SN_sha512_256, NID_sha512_256),
#endif
/* sha3 */
#ifdef Py_hash_sha3_224
PY_HASH_ENTRY(Py_hash_sha3_224, NULL, SN_sha3_224, NID_sha3_224),
#endif
#ifdef Py_hash_sha3_256
PY_HASH_ENTRY(Py_hash_sha3_256, NULL, SN_sha3_256, NID_sha3_256),
#endif
#ifdef Py_hash_sha3_384
PY_HASH_ENTRY(Py_hash_sha3_384, NULL, SN_sha3_384, NID_sha3_384),
#endif
#ifdef Py_hash_sha3_512
PY_HASH_ENTRY(Py_hash_sha3_512, NULL, SN_sha3_512, NID_sha3_512),
#endif
/* sha3 shake */
#ifdef Py_hash_shake_128
PY_HASH_ENTRY(Py_hash_shake_128, NULL, SN_shake128, NID_shake128),
#endif
#ifdef Py_hash_shake_256
PY_HASH_ENTRY(Py_hash_shake_256, NULL, SN_shake256, NID_shake256),
#endif
/* blake2 digest */
#ifdef Py_hash_blake2s
PY_HASH_ENTRY(Py_hash_blake2s, "blake2s256", SN_blake2s256, NID_blake2s256),
#endif
#ifdef Py_hash_blake2b
PY_HASH_ENTRY(Py_hash_blake2b, "blake2b512", SN_blake2b512, NID_blake2b512),
#endif
PY_HASH_ENTRY(NULL, NULL, NULL, 0),
};
static Py_uhash_t
py_hashentry_t_hash_name(const void *key) {
return Py_HashBuffer(key, strlen((const char *)key));
}
static int
py_hashentry_t_compare_name(const void *key1, const void *key2) {
return strcmp((const char *)key1, (const char *)key2) == 0;
}
static void
py_hashentry_t_destroy_value(void *entry) {
py_hashentry_t *h = (py_hashentry_t *)entry;
if (--(h->refcnt) == 0) {
if (h->evp != NULL) {
PY_EVP_MD_free(h->evp);
h->evp = NULL;
}
if (h->evp_nosecurity != NULL) {
PY_EVP_MD_free(h->evp_nosecurity);
h->evp_nosecurity = NULL;
}
PyMem_Free(entry);
}
}
static _Py_hashtable_t *
py_hashentry_table_new(void) {
_Py_hashtable_t *ht = _Py_hashtable_new_full(
py_hashentry_t_hash_name,
py_hashentry_t_compare_name,
NULL,
py_hashentry_t_destroy_value,
NULL
);
if (ht == NULL) {
return NULL;
}
for (const py_hashentry_t *h = py_hashes; h->py_name != NULL; h++) {
py_hashentry_t *entry = (py_hashentry_t *)PyMem_Malloc(sizeof(py_hashentry_t));
if (entry == NULL) {
goto error;
}
memcpy(entry, h, sizeof(py_hashentry_t));
if (_Py_hashtable_set(ht, (const void*)entry->py_name, (void*)entry) < 0) {
PyMem_Free(entry);
goto error;
}
entry->refcnt = 1;
if (h->py_alias != NULL) {
if (_Py_hashtable_set(ht, (const void*)entry->py_alias, (void*)entry) < 0) {
PyMem_Free(entry);
goto error;
}
entry->refcnt++;
}
}
return ht;
error:
_Py_hashtable_destroy(ht);
return NULL;
}
// --- Module state -----------------------------------------------------------
static PyModuleDef _hashlibmodule;
typedef struct {
PyTypeObject *HASH_type; // based on EVP_MD
PyTypeObject *HMAC_type;
#ifdef PY_OPENSSL_HAS_SHAKE
PyTypeObject *HASHXOF_type; // based on EVP_MD
#endif
PyObject *constructs;
PyObject *unsupported_digestmod_error;
_Py_hashtable_t *hashtable;
} _hashlibstate;
static inline _hashlibstate*
get_hashlib_state(PyObject *module)
{
void *state = PyModule_GetState(module);
assert(state != NULL);
return (_hashlibstate *)state;
}
// --- Module objects ---------------------------------------------------------
typedef struct {
HASHLIB_OBJECT_HEAD
EVP_MD_CTX *ctx; /* OpenSSL message digest context */
} HASHobject;
#define HASHobject_CAST(op) ((HASHobject *)(op))
typedef struct {
HASHLIB_OBJECT_HEAD
HMAC_CTX *ctx; /* OpenSSL hmac context */
} HMACobject;
#define HMACobject_CAST(op) ((HMACobject *)(op))
// --- Module clinic configuration --------------------------------------------
/*[clinic input]
module _hashlib
class _hashlib.HASH "HASHobject *" "&PyType_Type"
class _hashlib.HASHXOF "HASHobject *" "&PyType_Type"
class _hashlib.HMAC "HMACobject *" "&PyType_Type"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=6b5c9ce5c28bdc58]*/
#include "clinic/_hashopenssl.c.h"
/* LCOV_EXCL_START */
/* Thin wrapper around ERR_reason_error_string() returning non-NULL text. */
static const char *
py_wrapper_ERR_reason_error_string(unsigned long errcode)
{
const char *reason = ERR_reason_error_string(errcode);
return reason ? reason : "no reason";
}
#ifdef Py_HAS_OPENSSL3_SUPPORT
/*
* Set an exception with additional information.
*
* This is only useful in OpenSSL 3.0 and later as the default reason
* usually lacks information and function locations are no longer encoded
* in the error code.
*/
static void
set_exception_with_ssl_errinfo(PyObject *exc_type, PyObject *exc_text,
const char *lib, const char *reason)
{
assert(exc_type != NULL);
assert(exc_text != NULL);
if (lib && reason) {
PyErr_Format(exc_type, "[%s] %U (reason: %s)", lib, exc_text, reason);
}
else if (lib) {
PyErr_Format(exc_type, "[%s] %U", lib, exc_text);
}
else if (reason) {
PyErr_Format(exc_type, "%U (reason: %s)", exc_text, reason);
}
else {
PyErr_SetObject(exc_type, exc_text);
}
}
#endif
/* Set an exception of given type using the given OpenSSL error code. */
static void
set_ssl_exception_from_errcode(PyObject *exc_type, unsigned long errcode)
{
assert(exc_type != NULL);
assert(errcode != 0);
/* ERR_ERROR_STRING(3) ensures that the messages below are ASCII */
const char *lib = ERR_lib_error_string(errcode);
#ifdef Py_HAS_OPENSSL3_SUPPORT
// Since OpenSSL 3.0, ERR_func_error_string() always returns NULL.
const char *func = NULL;
#else
const char *func = ERR_func_error_string(errcode);
#endif
const char *reason = py_wrapper_ERR_reason_error_string(errcode);
if (lib && func) {
PyErr_Format(exc_type, "[%s: %s] %s", lib, func, reason);
}
else if (lib) {
PyErr_Format(exc_type, "[%s] %s", lib, reason);
}
else {
PyErr_SetString(exc_type, reason);
}
}
/*
* Get an appropriate exception type for the given OpenSSL error code.
*
* The exception type depends on the error code reason.
*/
static PyObject *
get_smart_ssl_exception_type(unsigned long errcode, PyObject *default_exc_type)
{
switch (ERR_GET_REASON(errcode)) {
case ERR_R_MALLOC_FAILURE:
return PyExc_MemoryError;
default:
return default_exc_type;
}
}
/*
* Set an exception of given type.
*
* By default, the exception's message is constructed by using the last SSL
* error that occurred. If no error occurred, the 'fallback_message' is used
* to create an exception message.
*/
static void
raise_ssl_error(PyObject *exc_type, const char *fallback_message)
{
assert(fallback_message != NULL);
unsigned long errcode = ERR_peek_last_error();
if (errcode) {
ERR_clear_error();
set_ssl_exception_from_errcode(exc_type, errcode);
}
else {
PyErr_SetString(exc_type, fallback_message);
}
}
/* Same as raise_ssl_error() but with a C-style formatted message. */
static void
raise_ssl_error_f(PyObject *exc_type, const char *fallback_format, ...)
{
assert(fallback_format != NULL);
unsigned long errcode = ERR_peek_last_error();
if (errcode) {
ERR_clear_error();
set_ssl_exception_from_errcode(exc_type, errcode);
}
else {
va_list vargs;
va_start(vargs, fallback_format);
PyErr_FormatV(exc_type, fallback_format, vargs);
va_end(vargs);
}
}
/* Same as raise_ssl_error_f() with smart exception types. */
static void
raise_smart_ssl_error_f(PyObject *exc_type, const char *fallback_format, ...)
{
unsigned long errcode = ERR_peek_last_error();
if (errcode) {
ERR_clear_error();
exc_type = get_smart_ssl_exception_type(errcode, exc_type);
set_ssl_exception_from_errcode(exc_type, errcode);
}
else {
va_list vargs;
va_start(vargs, fallback_format);
PyErr_FormatV(exc_type, fallback_format, vargs);
va_end(vargs);
}
}
/*
* Raise a ValueError with a default message after an error occurred.
* It can also be used without previous calls to SSL built-in functions.
*/
static inline void
notify_ssl_error_occurred(const char *message)
{
raise_ssl_error(PyExc_ValueError, message);
}
/* Same as notify_ssl_error_occurred() for failed OpenSSL functions. */
static inline void
notify_ssl_error_occurred_in(const char *funcname)
{
raise_ssl_error_f(PyExc_ValueError,
"error in OpenSSL function %s()", funcname);
}
/* Same as notify_ssl_error_occurred_in() with smart exception types. */
static inline void
notify_smart_ssl_error_occurred_in(const char *funcname)
{
raise_smart_ssl_error_f(PyExc_ValueError,
"error in OpenSSL function %s()", funcname);
}
#ifdef Py_HAS_OPENSSL3_SUPPORT
static void
raise_unsupported_algorithm_impl(PyObject *exc_type,
const char *fallback_format,
const void *format_arg)
{
// Since OpenSSL 3.0, if the algorithm is not supported or fetching fails,
// the reason lacks the algorithm name.
int errcode = ERR_peek_last_error();
switch (ERR_GET_REASON(errcode)) {
case ERR_R_UNSUPPORTED: {
PyObject *text = PyUnicode_FromFormat(fallback_format, format_arg);
if (text != NULL) {
const char *lib = ERR_lib_error_string(errcode);
set_exception_with_ssl_errinfo(exc_type, text, lib, NULL);
Py_DECREF(text);
}
break;
}
case ERR_R_FETCH_FAILED: {
PyObject *text = PyUnicode_FromFormat(fallback_format, format_arg);
if (text != NULL) {
const char *lib = ERR_lib_error_string(errcode);
const char *reason = ERR_reason_error_string(errcode);
set_exception_with_ssl_errinfo(exc_type, text, lib, reason);
Py_DECREF(text);
}
break;
}
default:
raise_ssl_error_f(exc_type, fallback_format, format_arg);
break;
}
assert(PyErr_Occurred());
}
#else
/* Before OpenSSL 3.0, error messages included enough information. */
#define raise_unsupported_algorithm_impl raise_ssl_error_f
#endif
static inline void
raise_unsupported_algorithm_error(_hashlibstate *state, PyObject *digestmod)
{
raise_unsupported_algorithm_impl(
state->unsupported_digestmod_error,
HASHLIB_UNSUPPORTED_ALGORITHM,
digestmod
);
}
static inline void
raise_unsupported_str_algorithm_error(_hashlibstate *state, const char *name)
{
raise_unsupported_algorithm_impl(
state->unsupported_digestmod_error,
HASHLIB_UNSUPPORTED_STR_ALGORITHM,
name
);
}
#undef raise_unsupported_algorithm_impl
/* LCOV_EXCL_STOP */
/*
* OpenSSL provides a way to go from NIDs to digest names for hash functions
* but lacks this granularity for MAC objects where it is not possible to get
* the underlying digest name (only the block size and digest size are allowed
* to be recovered).
*
* In addition, OpenSSL aliases pollute the list of known digest names
* as OpenSSL appears to have its own definition of alias. In particular,
* the resulting list still contains duplicate and alternate names for several
* algorithms.
*
* Therefore, digest names, whether they are used by hash functions or HMAC,
* are handled through EVP_MD objects or directly by using some NID.
*/
/* Get a cached entry by OpenSSL NID. */
static const py_hashentry_t *
get_hashentry_by_nid(int nid)
{
for (const py_hashentry_t *h = py_hashes; h->py_name != NULL; h++) {
if (h->ossl_nid == nid) {
return h;
}
}
return NULL;
}
/*
* Convert the NID to a string via OBJ_nid2*() functions.
*
* If 'nid' cannot be resolved, set an exception and return NULL.
*/
static const char *
get_asn1_utf8name_by_nid(int nid)
{
const char *name = OBJ_nid2ln(nid);
if (name == NULL) {
// In OpenSSL 3.0 and later, OBJ_nid*() are thread-safe and may raise.
assert(ERR_peek_last_error() != 0);
if (ERR_GET_REASON(ERR_peek_last_error()) != OBJ_R_UNKNOWN_NID) {
goto error;
}
// fallback to short name and unconditionally propagate errors
name = OBJ_nid2sn(nid);
if (name == NULL) {
goto error;
}
}
return name;
error:
raise_ssl_error_f(PyExc_ValueError, "cannot resolve NID %d", nid);
return NULL;
}
/*
* Convert the NID to an OpenSSL digest name.
*
* On error, set an exception and return NULL.
*/
static const char *
get_hashlib_utf8name_by_nid(int nid)
{
const py_hashentry_t *e = get_hashentry_by_nid(nid);
return e ? e->py_name : get_asn1_utf8name_by_nid(nid);
}
/* Same as get_hashlib_utf8name_by_nid() but using an EVP_MD object. */
static const char *
get_hashlib_utf8name_by_evp_md(const EVP_MD *md)
{
assert(md != NULL);
return get_hashlib_utf8name_by_nid(EVP_MD_nid(md));
}
/*
* Return 1 if the property query clause [1] must be "-fips" and 0 otherwise.
*
* [1] https://docs.openssl.org/master/man7/property
*/
static inline int
disable_fips_property(Py_hash_type py_ht)
{
switch (py_ht) {
case Py_ht_evp:
case Py_ht_mac:
case Py_ht_pbkdf2:
return 0;
case Py_ht_evp_nosecurity:
return 1;
default:
Py_FatalError("unsupported hash type");
}
}
/*
* Get a new reference to an EVP_MD object described by name and purpose.
*
* If 'name' is an OpenSSL indexed name, the return value is cached.
*/
static PY_EVP_MD *
get_openssl_evp_md_by_utf8name(_hashlibstate *state, const char *name,
Py_hash_type py_ht)
{
PY_EVP_MD *digest = NULL, *other_digest = NULL;
py_hashentry_t *entry = _Py_hashtable_get(state->hashtable, name);
if (entry != NULL) {
if (!disable_fips_property(py_ht)) {
digest = FT_ATOMIC_LOAD_PTR_RELAXED(entry->evp);
if (digest == NULL) {
digest = PY_EVP_MD_fetch(entry->ossl_name, NULL);
#ifdef Py_GIL_DISABLED
// exchange just in case another thread did same thing at same time
other_digest = _Py_atomic_exchange_ptr(&entry->evp, (void *)digest);
#else
entry->evp = digest;
#endif
}
}
else {
digest = FT_ATOMIC_LOAD_PTR_RELAXED(entry->evp_nosecurity);
if (digest == NULL) {
digest = PY_EVP_MD_fetch(entry->ossl_name, "-fips");
#ifdef Py_GIL_DISABLED
// exchange just in case another thread did same thing at same time
other_digest = _Py_atomic_exchange_ptr(&entry->evp_nosecurity, (void *)digest);
#else
entry->evp_nosecurity = digest;
#endif
}
}
// if another thread same thing at same time make sure we got same ptr
assert(other_digest == NULL || other_digest == digest);
if (digest != NULL && other_digest == NULL) {
PY_EVP_MD_up_ref(digest);
}
}
else {
// Fall back for looking up an unindexed OpenSSL specific name.
const char *props = disable_fips_property(py_ht) ? "-fips" : NULL;
(void)props; // will only be used in OpenSSL 3.0 and later
digest = PY_EVP_MD_fetch(name, props);
}
if (digest == NULL) {
raise_unsupported_str_algorithm_error(state, name);
return NULL;
}
return digest;
}
/*
* Get a new reference to an EVP_MD described by 'digestmod' and purpose.
*
* On error, set an exception and return NULL.
*
* Parameters
*
* digestmod A digest name or a _hashopenssl builtin function
* py_ht The message digest purpose.
*/
static PY_EVP_MD *
get_openssl_evp_md(_hashlibstate *state, PyObject *digestmod, Py_hash_type py_ht)
{
const char *name;
if (PyUnicode_Check(digestmod)) {
name = PyUnicode_AsUTF8(digestmod);
}
else {
PyObject *dict = state->constructs;
assert(dict != NULL);
PyObject *borrowed_ref = PyDict_GetItemWithError(dict, digestmod);
name = borrowed_ref == NULL ? NULL : PyUnicode_AsUTF8(borrowed_ref);
}
if (name == NULL) {
if (!PyErr_Occurred()) {
raise_unsupported_algorithm_error(state, digestmod);
}
return NULL;
}
return get_openssl_evp_md_by_utf8name(state, name, py_ht);
}
// --- OpenSSL HASH wrappers --------------------------------------------------
/* Thin wrapper around EVP_MD_CTX_new() which sets an exception on failure. */
static EVP_MD_CTX *
py_wrapper_EVP_MD_CTX_new(void)
{
EVP_MD_CTX *ctx = EVP_MD_CTX_new();
if (ctx == NULL) {
PyErr_NoMemory();
return NULL;
}
return ctx;
}
// --- HASH interface ---------------------------------------------------------
static HASHobject *
new_hash_object(PyTypeObject *type)
{
HASHobject *retval = PyObject_New(HASHobject, type);
if (retval == NULL) {
return NULL;
}
HASHLIB_INIT_MUTEX(retval);
retval->ctx = py_wrapper_EVP_MD_CTX_new();
if (retval->ctx == NULL) {
Py_DECREF(retval);
return NULL;
}
return retval;
}
static int
_hashlib_HASH_hash(HASHobject *self, const void *vp, Py_ssize_t len)
{
unsigned int process;
const unsigned char *cp = (const unsigned char *)vp;
while (0 < len) {
if (len > (Py_ssize_t)MUNCH_SIZE)
process = MUNCH_SIZE;
else
process = Py_SAFE_DOWNCAST(len, Py_ssize_t, unsigned int);
if (!EVP_DigestUpdate(self->ctx, (const void*)cp, process)) {
notify_ssl_error_occurred_in(Py_STRINGIFY(EVP_DigestUpdate));
return -1;
}
len -= process;
cp += process;
}
return 0;
}
/* Internal methods for a hash object */
static void
_hashlib_HASH_dealloc(PyObject *op)
{
HASHobject *self = HASHobject_CAST(op);
PyTypeObject *tp = Py_TYPE(self);
EVP_MD_CTX_free(self->ctx);
PyObject_Free(self);
Py_DECREF(tp);
}
static int
_hashlib_HASH_copy_locked(HASHobject *self, EVP_MD_CTX *new_ctx_p)
{
int result;
HASHLIB_ACQUIRE_LOCK(self);
result = EVP_MD_CTX_copy(new_ctx_p, self->ctx);
HASHLIB_RELEASE_LOCK(self);
if (result == 0) {
notify_smart_ssl_error_occurred_in(Py_STRINGIFY(EVP_MD_CTX_copy));
return -1;
}
return 0;
}
/* External methods for a hash object */
/*[clinic input]
_hashlib.HASH.copy
Return a copy of the hash object.
[clinic start generated code]*/
static PyObject *
_hashlib_HASH_copy_impl(HASHobject *self)
/*[clinic end generated code: output=2545541af18d53d7 input=814b19202cd08a26]*/
{
HASHobject *newobj;
if ((newobj = new_hash_object(Py_TYPE(self))) == NULL)
return NULL;
if (_hashlib_HASH_copy_locked(self, newobj->ctx) < 0) {
Py_DECREF(newobj);
return NULL;
}
return (PyObject *)newobj;
}
static Py_ssize_t
_hashlib_HASH_digest_compute(HASHobject *self, unsigned char *digest)
{
EVP_MD_CTX *ctx = py_wrapper_EVP_MD_CTX_new();
if (ctx == NULL) {
return -1;
}
if (_hashlib_HASH_copy_locked(self, ctx) < 0) {
goto error;
}
Py_ssize_t digest_size = EVP_MD_CTX_size(ctx);
if (!EVP_DigestFinal(ctx, digest, NULL)) {
notify_ssl_error_occurred_in(Py_STRINGIFY(EVP_DigestFinal));
goto error;
}
EVP_MD_CTX_free(ctx);
return digest_size;
error:
EVP_MD_CTX_free(ctx);
return -1;
}
/*[clinic input]
_hashlib.HASH.digest
Return the digest value as a bytes object.
[clinic start generated code]*/
static PyObject *
_hashlib_HASH_digest_impl(HASHobject *self)
/*[clinic end generated code: output=3fc6f9671d712850 input=d8d528d6e50af0de]*/
{
unsigned char digest[EVP_MAX_MD_SIZE];
Py_ssize_t n = _hashlib_HASH_digest_compute(self, digest);
return n < 0 ? NULL : PyBytes_FromStringAndSize((const char *)digest, n);
}
/*[clinic input]
_hashlib.HASH.hexdigest
Return the digest value as a string of hexadecimal digits.
[clinic start generated code]*/
static PyObject *
_hashlib_HASH_hexdigest_impl(HASHobject *self)
/*[clinic end generated code: output=1b8e60d9711e7f4d input=ae7553f78f8372d8]*/
{
unsigned char digest[EVP_MAX_MD_SIZE];
Py_ssize_t n = _hashlib_HASH_digest_compute(self, digest);
return n < 0 ? NULL : _Py_strhex((const char *)digest, n);
}
/*[clinic input]
_hashlib.HASH.update
obj: object
/
Update this hash object's state with the provided string.
[clinic start generated code]*/
static PyObject *
_hashlib_HASH_update_impl(HASHobject *self, PyObject *obj)
/*[clinic end generated code: output=62ad989754946b86 input=aa1ce20e3f92ceb6]*/
{
int result;
Py_buffer view;
GET_BUFFER_VIEW_OR_ERROUT(obj, &view);
HASHLIB_EXTERNAL_INSTRUCTIONS_LOCKED(
self, view.len,
result = _hashlib_HASH_hash(self, view.buf, view.len)
);
PyBuffer_Release(&view);
return result < 0 ? NULL : Py_None;
}
static PyMethodDef HASH_methods[] = {
_HASHLIB_HASH_COPY_METHODDEF
_HASHLIB_HASH_DIGEST_METHODDEF
_HASHLIB_HASH_HEXDIGEST_METHODDEF
_HASHLIB_HASH_UPDATE_METHODDEF
{NULL, NULL} /* sentinel */
};
static PyObject *
_hashlib_HASH_get_blocksize(PyObject *op, void *Py_UNUSED(closure))
{
HASHobject *self = HASHobject_CAST(op);
long block_size = EVP_MD_CTX_block_size(self->ctx);
return PyLong_FromLong(block_size);
}
static PyObject *
_hashlib_HASH_get_digestsize(PyObject *op, void *Py_UNUSED(closure))
{
HASHobject *self = HASHobject_CAST(op);
long size = EVP_MD_CTX_size(self->ctx);
return PyLong_FromLong(size);
}
static PyObject *
_hashlib_HASH_get_name(PyObject *op, void *Py_UNUSED(closure))
{
HASHobject *self = HASHobject_CAST(op);
const EVP_MD *md = PY_EVP_MD_CTX_md(self->ctx);
if (md == NULL) {
notify_ssl_error_occurred("missing EVP_MD for HASH context");
return NULL;
}
const char *name = get_hashlib_utf8name_by_evp_md(md);
assert(name != NULL || PyErr_Occurred());
return name == NULL ? NULL : PyUnicode_FromString(name);
}
static PyGetSetDef HASH_getsets[] = {
{"digest_size", _hashlib_HASH_get_digestsize, NULL, NULL, NULL},
{"block_size", _hashlib_HASH_get_blocksize, NULL, NULL, NULL},
{"name", _hashlib_HASH_get_name, NULL, NULL, PyDoc_STR("algorithm name.")},
{NULL} /* Sentinel */
};
static PyObject *
_hashlib_HASH_repr(PyObject *self)
{
PyObject *name = _hashlib_HASH_get_name(self, NULL);
if (name == NULL) {
return NULL;
}
PyObject *repr = PyUnicode_FromFormat("<%U %T object @ %p>",
name, self, self);
Py_DECREF(name);
return repr;
}
PyDoc_STRVAR(HASHobject_type_doc,
"HASH(name, string=b\'\')\n"
"--\n"
"\n"
"A hash is an object used to calculate a checksum of a string of information.\n"
"\n"
"Methods:\n"
"\n"
"update() -- updates the current digest with an additional string\n"
"digest() -- return the current digest value\n"
"hexdigest() -- return the current digest as a string of hexadecimal digits\n"
"copy() -- return a copy of the current hash object\n"
"\n"
"Attributes:\n"
"\n"
"name -- the hash algorithm being used by this object\n"
"digest_size -- number of bytes in this hashes output");
static PyType_Slot HASHobject_type_slots[] = {
{Py_tp_dealloc, _hashlib_HASH_dealloc},
{Py_tp_repr, _hashlib_HASH_repr},
{Py_tp_doc, (char *)HASHobject_type_doc},
{Py_tp_methods, HASH_methods},
{Py_tp_getset, HASH_getsets},
{0, 0},
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