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cpython/Modules/_hashopenssl.c
Gregory P. Smith c7e219132a
Dead code removal from _hashopenssl. (GH-11379) 
HASH_OBJ_CONSTRUCTOR has always been defined as 0 since I created
hashlib in Python 2.5.  Delete all code associated with it.
2018-12-30 17:54:53 -08:00

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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)
*
*/
#define PY_SSIZE_T_CLEAN
#include "Python.h"
#include "structmember.h"
#include "hashlib.h"
#include "pystrhex.h"
/* EVP is the preferred interface to hashing in OpenSSL */
#include <openssl/evp.h>
#include <openssl/hmac.h>
/* We use the object interface to discover what hashes OpenSSL supports. */
#include <openssl/objects.h>
#include "openssl/err.h"
#define MUNCH_SIZE INT_MAX
#if (OPENSSL_VERSION_NUMBER < 0x10100000L) || defined(LIBRESSL_VERSION_NUMBER)
/* OpenSSL < 1.1.0 */
#define EVP_MD_CTX_new EVP_MD_CTX_create
#define EVP_MD_CTX_free EVP_MD_CTX_destroy
#define HAS_FAST_PKCS5_PBKDF2_HMAC 0
#include <openssl/hmac.h>
#else
/* OpenSSL >= 1.1.0 */
#define HAS_FAST_PKCS5_PBKDF2_HMAC 1
#endif
typedef struct {
PyObject_HEAD
PyObject *name; /* name of this hash algorithm */
EVP_MD_CTX *ctx; /* OpenSSL message digest context */
PyThread_type_lock lock; /* OpenSSL context lock */
} EVPobject;
static PyTypeObject EVPtype;
#define DEFINE_CONSTS_FOR_NEW(Name) \
static PyObject *CONST_ ## Name ## _name_obj = NULL; \
static EVP_MD_CTX *CONST_new_ ## Name ## _ctx_p = NULL;
DEFINE_CONSTS_FOR_NEW(md5)
DEFINE_CONSTS_FOR_NEW(sha1)
DEFINE_CONSTS_FOR_NEW(sha224)
DEFINE_CONSTS_FOR_NEW(sha256)
DEFINE_CONSTS_FOR_NEW(sha384)
DEFINE_CONSTS_FOR_NEW(sha512)
#include "clinic/_hashopenssl.c.h"
/*[clinic input]
module _hashlib
class _hashlib.HASH "EVPobject *" "&EVPtype"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=a881a5092eecad28]*/
/* LCOV_EXCL_START */
static PyObject *
_setException(PyObject *exc)
{
unsigned long errcode;
const char *lib, *func, *reason;
errcode = ERR_peek_last_error();
if (!errcode) {
PyErr_SetString(exc, "unknown reasons");
return NULL;
}
ERR_clear_error();
lib = ERR_lib_error_string(errcode);
func = ERR_func_error_string(errcode);
reason = ERR_reason_error_string(errcode);
if (lib && func) {
PyErr_Format(exc, "[%s: %s] %s", lib, func, reason);
}
else if (lib) {
PyErr_Format(exc, "[%s] %s", lib, reason);
}
else {
PyErr_SetString(exc, reason);
}
return NULL;
}
/* LCOV_EXCL_STOP */
static EVPobject *
newEVPobject(PyObject *name)
{
EVPobject *retval = (EVPobject *)PyObject_New(EVPobject, &EVPtype);
if (retval == NULL) {
return NULL;
}
retval->ctx = EVP_MD_CTX_new();
if (retval->ctx == NULL) {
PyErr_NoMemory();
return NULL;
}
/* save the name for .name to return */
Py_INCREF(name);
retval->name = name;
retval->lock = NULL;
return retval;
}
static void
EVP_hash(EVPobject *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)) {
_setException(PyExc_ValueError);
break;
}
len -= process;
cp += process;
}
}
/* Internal methods for a hash object */
static void
EVP_dealloc(EVPobject *self)
{
if (self->lock != NULL)
PyThread_free_lock(self->lock);
EVP_MD_CTX_free(self->ctx);
Py_XDECREF(self->name);
PyObject_Del(self);
}
static int
locked_EVP_MD_CTX_copy(EVP_MD_CTX *new_ctx_p, EVPobject *self)
{
int result;
ENTER_HASHLIB(self);
result = EVP_MD_CTX_copy(new_ctx_p, self->ctx);
LEAVE_HASHLIB(self);
return result;
}
/* External methods for a hash object */
/*[clinic input]
_hashlib.HASH.copy as EVP_copy
Return a copy of the hash object.
[clinic start generated code]*/
static PyObject *
EVP_copy_impl(EVPobject *self)
/*[clinic end generated code: output=b370c21cdb8ca0b4 input=31455b6a3e638069]*/
{
EVPobject *newobj;
if ( (newobj = newEVPobject(self->name))==NULL)
return NULL;
if (!locked_EVP_MD_CTX_copy(newobj->ctx, self)) {
return _setException(PyExc_ValueError);
}
return (PyObject *)newobj;
}
/*[clinic input]
_hashlib.HASH.digest as EVP_digest
Return the digest value as a bytes object.
[clinic start generated code]*/
static PyObject *
EVP_digest_impl(EVPobject *self)
/*[clinic end generated code: output=0f6a3a0da46dc12d input=03561809a419bf00]*/
{
unsigned char digest[EVP_MAX_MD_SIZE];
EVP_MD_CTX *temp_ctx;
PyObject *retval;
unsigned int digest_size;
temp_ctx = EVP_MD_CTX_new();
if (temp_ctx == NULL) {
PyErr_NoMemory();
return NULL;
}
if (!locked_EVP_MD_CTX_copy(temp_ctx, self)) {
return _setException(PyExc_ValueError);
}
digest_size = EVP_MD_CTX_size(temp_ctx);
if (!EVP_DigestFinal(temp_ctx, digest, NULL)) {
_setException(PyExc_ValueError);
return NULL;
}
retval = PyBytes_FromStringAndSize((const char *)digest, digest_size);
EVP_MD_CTX_free(temp_ctx);
return retval;
}
/*[clinic input]
_hashlib.HASH.hexdigest as EVP_hexdigest
Return the digest value as a string of hexadecimal digits.
[clinic start generated code]*/
static PyObject *
EVP_hexdigest_impl(EVPobject *self)
/*[clinic end generated code: output=18e6decbaf197296 input=aff9cf0e4c741a9a]*/
{
unsigned char digest[EVP_MAX_MD_SIZE];
EVP_MD_CTX *temp_ctx;
unsigned int digest_size;
temp_ctx = EVP_MD_CTX_new();
if (temp_ctx == NULL) {
PyErr_NoMemory();
return NULL;
}
/* Get the raw (binary) digest value */
if (!locked_EVP_MD_CTX_copy(temp_ctx, self)) {
return _setException(PyExc_ValueError);
}
digest_size = EVP_MD_CTX_size(temp_ctx);
if (!EVP_DigestFinal(temp_ctx, digest, NULL)) {
_setException(PyExc_ValueError);
return NULL;
}
EVP_MD_CTX_free(temp_ctx);
return _Py_strhex((const char *)digest, (Py_ssize_t)digest_size);
}
/*[clinic input]
_hashlib.HASH.update as EVP_update
obj: object
/
Update this hash object's state with the provided string.
[clinic start generated code]*/
static PyObject *
EVP_update(EVPobject *self, PyObject *obj)
/*[clinic end generated code: output=ec1d55ed2432e966 input=9b30ec848f015501]*/
{
Py_buffer view;
GET_BUFFER_VIEW_OR_ERROUT(obj, &view);
if (self->lock == NULL && view.len >= HASHLIB_GIL_MINSIZE) {
self->lock = PyThread_allocate_lock();
/* fail? lock = NULL and we fail over to non-threaded code. */
}
if (self->lock != NULL) {
Py_BEGIN_ALLOW_THREADS
PyThread_acquire_lock(self->lock, 1);
EVP_hash(self, view.buf, view.len);
PyThread_release_lock(self->lock);
Py_END_ALLOW_THREADS
} else {
EVP_hash(self, view.buf, view.len);
}
PyBuffer_Release(&view);
Py_RETURN_NONE;
}
static PyMethodDef EVP_methods[] = {
EVP_UPDATE_METHODDEF
EVP_DIGEST_METHODDEF
EVP_HEXDIGEST_METHODDEF
EVP_COPY_METHODDEF
{NULL, NULL} /* sentinel */
};
static PyObject *
EVP_get_block_size(EVPobject *self, void *closure)
{
long block_size;
block_size = EVP_MD_CTX_block_size(self->ctx);
return PyLong_FromLong(block_size);
}
static PyObject *
EVP_get_digest_size(EVPobject *self, void *closure)
{
long size;
size = EVP_MD_CTX_size(self->ctx);
return PyLong_FromLong(size);
}
static PyMemberDef EVP_members[] = {
{"name", T_OBJECT, offsetof(EVPobject, name), READONLY, PyDoc_STR("algorithm name.")},
{NULL} /* Sentinel */
};
static PyGetSetDef EVP_getseters[] = {
{"digest_size",
(getter)EVP_get_digest_size, NULL,
NULL,
NULL},
{"block_size",
(getter)EVP_get_block_size, NULL,
NULL,
NULL},
{NULL} /* Sentinel */
};
static PyObject *
EVP_repr(EVPobject *self)
{
return PyUnicode_FromFormat("<%U HASH object @ %p>", self->name, self);
}
PyDoc_STRVAR(hashtype_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 PyTypeObject EVPtype = {
PyVarObject_HEAD_INIT(NULL, 0)
"_hashlib.HASH", /*tp_name*/
sizeof(EVPobject), /*tp_basicsize*/
0, /*tp_itemsize*/
/* methods */
(destructor)EVP_dealloc, /*tp_dealloc*/
0, /*tp_print*/
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_reserved*/
(reprfunc)EVP_repr, /*tp_repr*/
0, /*tp_as_number*/
0, /*tp_as_sequence*/
0, /*tp_as_mapping*/
0, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
hashtype_doc, /*tp_doc*/
0, /*tp_traverse*/
0, /*tp_clear*/
0, /*tp_richcompare*/
0, /*tp_weaklistoffset*/
0, /*tp_iter*/
0, /*tp_iternext*/
EVP_methods, /* tp_methods */
EVP_members, /* tp_members */
EVP_getseters, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
};
static PyObject *
EVPnew(PyObject *name_obj,
const EVP_MD *digest, const EVP_MD_CTX *initial_ctx,
const unsigned char *cp, Py_ssize_t len)
{
EVPobject *self;
if (!digest && !initial_ctx) {
PyErr_SetString(PyExc_ValueError, "unsupported hash type");
return NULL;
}
if ((self = newEVPobject(name_obj)) == NULL)
return NULL;
if (initial_ctx) {
EVP_MD_CTX_copy(self->ctx, initial_ctx);
} else {
if (!EVP_DigestInit(self->ctx, digest)) {
_setException(PyExc_ValueError);
Py_DECREF(self);
return NULL;
}
}
if (cp && len) {
if (len >= HASHLIB_GIL_MINSIZE) {
Py_BEGIN_ALLOW_THREADS
EVP_hash(self, cp, len);
Py_END_ALLOW_THREADS
} else {
EVP_hash(self, cp, len);
}
}
return (PyObject *)self;
}
/* The module-level function: new() */
/*[clinic input]
_hashlib.new as EVP_new
name as name_obj: object
string as data_obj: object(py_default="b''") = NULL
Return a new hash object using the named algorithm.
An optional string argument may be provided and will be
automatically hashed.
The MD5 and SHA1 algorithms are always supported.
[clinic start generated code]*/
static PyObject *
EVP_new_impl(PyObject *module, PyObject *name_obj, PyObject *data_obj)
/*[clinic end generated code: output=9e7cf664e04b0226 input=1c46e40e0fec91f3]*/
{
Py_buffer view = { 0 };
PyObject *ret_obj;
char *name;
const EVP_MD *digest;
if (!PyArg_Parse(name_obj, "s", &name)) {
PyErr_SetString(PyExc_TypeError, "name must be a string");
return NULL;
}
if (data_obj)
GET_BUFFER_VIEW_OR_ERROUT(data_obj, &view);
digest = EVP_get_digestbyname(name);
ret_obj = EVPnew(name_obj, digest, NULL, (unsigned char*)view.buf, view.len);
if (data_obj)
PyBuffer_Release(&view);
return ret_obj;
}
#if (OPENSSL_VERSION_NUMBER >= 0x10000000 && !defined(OPENSSL_NO_HMAC) \
&& !defined(OPENSSL_NO_SHA))
#define PY_PBKDF2_HMAC 1
#if !HAS_FAST_PKCS5_PBKDF2_HMAC
/* Improved implementation of PKCS5_PBKDF2_HMAC()
*
* PKCS5_PBKDF2_HMAC_fast() hashes the password exactly one time instead of
* `iter` times. Today (2013) the iteration count is typically 100,000 or
* more. The improved algorithm is not subject to a Denial-of-Service
* vulnerability with overly large passwords.
*
* Also OpenSSL < 1.0 don't provide PKCS5_PBKDF2_HMAC(), only
* PKCS5_PBKDF2_SHA1.
*/
static int
PKCS5_PBKDF2_HMAC_fast(const char *pass, int passlen,
const unsigned char *salt, int saltlen,
int iter, const EVP_MD *digest,
int keylen, unsigned char *out)
{
unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];
int cplen, j, k, tkeylen, mdlen;
unsigned long i = 1;
HMAC_CTX hctx_tpl, hctx;
mdlen = EVP_MD_size(digest);
if (mdlen < 0)
return 0;
HMAC_CTX_init(&hctx_tpl);
HMAC_CTX_init(&hctx);
p = out;
tkeylen = keylen;
if (!HMAC_Init_ex(&hctx_tpl, pass, passlen, digest, NULL)) {
HMAC_CTX_cleanup(&hctx_tpl);
return 0;
}
while (tkeylen) {
if (tkeylen > mdlen)
cplen = mdlen;
else
cplen = tkeylen;
/* We are unlikely to ever use more than 256 blocks (5120 bits!)
* but just in case...
*/
itmp[0] = (unsigned char)((i >> 24) & 0xff);
itmp[1] = (unsigned char)((i >> 16) & 0xff);
itmp[2] = (unsigned char)((i >> 8) & 0xff);
itmp[3] = (unsigned char)(i & 0xff);
if (!HMAC_CTX_copy(&hctx, &hctx_tpl)) {
HMAC_CTX_cleanup(&hctx_tpl);
return 0;
}
if (!HMAC_Update(&hctx, salt, saltlen)
|| !HMAC_Update(&hctx, itmp, 4)
|| !HMAC_Final(&hctx, digtmp, NULL)) {
HMAC_CTX_cleanup(&hctx_tpl);
HMAC_CTX_cleanup(&hctx);
return 0;
}
HMAC_CTX_cleanup(&hctx);
memcpy(p, digtmp, cplen);
for (j = 1; j < iter; j++) {
if (!HMAC_CTX_copy(&hctx, &hctx_tpl)) {
HMAC_CTX_cleanup(&hctx_tpl);
return 0;
}
if (!HMAC_Update(&hctx, digtmp, mdlen)
|| !HMAC_Final(&hctx, digtmp, NULL)) {
HMAC_CTX_cleanup(&hctx_tpl);
HMAC_CTX_cleanup(&hctx);
return 0;
}
HMAC_CTX_cleanup(&hctx);
for (k = 0; k < cplen; k++) {
p[k] ^= digtmp[k];
}
}
tkeylen-= cplen;
i++;
p+= cplen;
}
HMAC_CTX_cleanup(&hctx_tpl);
return 1;
}
#endif
/*[clinic input]
_hashlib.pbkdf2_hmac as pbkdf2_hmac
hash_name: str
password: Py_buffer
salt: Py_buffer
iterations: long
dklen as dklen_obj: object = None
Password based key derivation function 2 (PKCS #5 v2.0) with HMAC as pseudorandom function.
[clinic start generated code]*/
static PyObject *
pbkdf2_hmac_impl(PyObject *module, const char *hash_name,
Py_buffer *password, Py_buffer *salt, long iterations,
PyObject *dklen_obj)
/*[clinic end generated code: output=144b76005416599b input=ed3ab0d2d28b5d5c]*/
{
PyObject *key_obj = NULL;
char *key;
long dklen;
int retval;
const EVP_MD *digest;
digest = EVP_get_digestbyname(hash_name);
if (digest == NULL) {
PyErr_SetString(PyExc_ValueError, "unsupported hash type");
goto end;
}
if (password->len > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"password is too long.");
goto end;
}
if (salt->len > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"salt is too long.");
goto end;
}
if (iterations < 1) {
PyErr_SetString(PyExc_ValueError,
"iteration value must be greater than 0.");
goto end;
}
if (iterations > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"iteration value is too great.");
goto end;
}
if (dklen_obj == Py_None) {
dklen = EVP_MD_size(digest);
} else {
dklen = PyLong_AsLong(dklen_obj);
if ((dklen == -1) && PyErr_Occurred()) {
goto end;
}
}
if (dklen < 1) {
PyErr_SetString(PyExc_ValueError,
"key length must be greater than 0.");
goto end;
}
if (dklen > INT_MAX) {
/* INT_MAX is always smaller than dkLen max (2^32 - 1) * hLen */
PyErr_SetString(PyExc_OverflowError,
"key length is too great.");
goto end;
}
key_obj = PyBytes_FromStringAndSize(NULL, dklen);
if (key_obj == NULL) {
goto end;
}
key = PyBytes_AS_STRING(key_obj);
Py_BEGIN_ALLOW_THREADS
#if HAS_FAST_PKCS5_PBKDF2_HMAC
retval = PKCS5_PBKDF2_HMAC((char*)password->buf, (int)password->len,
(unsigned char *)salt->buf, (int)salt->len,
iterations, digest, dklen,
(unsigned char *)key);
#else
retval = PKCS5_PBKDF2_HMAC_fast((char*)password->buf, (int)password->len,
(unsigned char *)salt->buf, (int)salt->len,
iterations, digest, dklen,
(unsigned char *)key);
#endif
Py_END_ALLOW_THREADS
if (!retval) {
Py_CLEAR(key_obj);
_setException(PyExc_ValueError);
goto end;
}
end:
return key_obj;
}
#endif
#if OPENSSL_VERSION_NUMBER > 0x10100000L && !defined(OPENSSL_NO_SCRYPT) && !defined(LIBRESSL_VERSION_NUMBER)
#define PY_SCRYPT 1
/* XXX: Parameters salt, n, r and p should be required keyword-only parameters.
They are optional in the Argument Clinic declaration only due to a
limitation of PyArg_ParseTupleAndKeywords. */
/*[clinic input]
_hashlib.scrypt
password: Py_buffer
*
salt: Py_buffer = None
n as n_obj: object(subclass_of='&PyLong_Type') = None
r as r_obj: object(subclass_of='&PyLong_Type') = None
p as p_obj: object(subclass_of='&PyLong_Type') = None
maxmem: long = 0
dklen: long = 64
scrypt password-based key derivation function.
[clinic start generated code]*/
static PyObject *
_hashlib_scrypt_impl(PyObject *module, Py_buffer *password, Py_buffer *salt,
PyObject *n_obj, PyObject *r_obj, PyObject *p_obj,
long maxmem, long dklen)
/*[clinic end generated code: output=14849e2aa2b7b46c input=48a7d63bf3f75c42]*/
{
PyObject *key_obj = NULL;
char *key;
int retval;
unsigned long n, r, p;
if (password->len > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"password is too long.");
return NULL;
}
if (salt->buf == NULL) {
PyErr_SetString(PyExc_TypeError,
"salt is required");
return NULL;
}
if (salt->len > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"salt is too long.");
return NULL;
}
n = PyLong_AsUnsignedLong(n_obj);
if (n == (unsigned long) -1 && PyErr_Occurred()) {
PyErr_SetString(PyExc_TypeError,
"n is required and must be an unsigned int");
return NULL;
}
if (n < 2 || n & (n - 1)) {
PyErr_SetString(PyExc_ValueError,
"n must be a power of 2.");
return NULL;
}
r = PyLong_AsUnsignedLong(r_obj);
if (r == (unsigned long) -1 && PyErr_Occurred()) {
PyErr_SetString(PyExc_TypeError,
"r is required and must be an unsigned int");
return NULL;
}
p = PyLong_AsUnsignedLong(p_obj);
if (p == (unsigned long) -1 && PyErr_Occurred()) {
PyErr_SetString(PyExc_TypeError,
"p is required and must be an unsigned int");
return NULL;
}
if (maxmem < 0 || maxmem > INT_MAX) {
/* OpenSSL 1.1.0 restricts maxmem to 32 MiB. It may change in the
future. The maxmem constant is private to OpenSSL. */
PyErr_Format(PyExc_ValueError,
"maxmem must be positive and smaller than %d",
INT_MAX);
return NULL;
}
if (dklen < 1 || dklen > INT_MAX) {
PyErr_Format(PyExc_ValueError,
"dklen must be greater than 0 and smaller than %d",
INT_MAX);
return NULL;
}
/* let OpenSSL validate the rest */
retval = EVP_PBE_scrypt(NULL, 0, NULL, 0, n, r, p, maxmem, NULL, 0);
if (!retval) {
/* sorry, can't do much better */
PyErr_SetString(PyExc_ValueError,
"Invalid paramemter combination for n, r, p, maxmem.");
return NULL;
}
key_obj = PyBytes_FromStringAndSize(NULL, dklen);
if (key_obj == NULL) {
return NULL;
}
key = PyBytes_AS_STRING(key_obj);
Py_BEGIN_ALLOW_THREADS
retval = EVP_PBE_scrypt(
(const char*)password->buf, (size_t)password->len,
(const unsigned char *)salt->buf, (size_t)salt->len,
n, r, p, maxmem,
(unsigned char *)key, (size_t)dklen
);
Py_END_ALLOW_THREADS
if (!retval) {
Py_CLEAR(key_obj);
_setException(PyExc_ValueError);
return NULL;
}
return key_obj;
}
#endif
/* Fast HMAC for hmac.digest()
*/
/*[clinic input]
_hashlib.hmac_digest
key: Py_buffer
msg: Py_buffer
digest: str
Single-shot HMAC.
[clinic start generated code]*/
static PyObject *
_hashlib_hmac_digest_impl(PyObject *module, Py_buffer *key, Py_buffer *msg,
const char *digest)
/*[clinic end generated code: output=75630e684cdd8762 input=562d2f4249511bd3]*/
{
unsigned char md[EVP_MAX_MD_SIZE] = {0};
unsigned int md_len = 0;
unsigned char *result;
const EVP_MD *evp;
evp = EVP_get_digestbyname(digest);
if (evp == NULL) {
PyErr_SetString(PyExc_ValueError, "unsupported hash type");
return NULL;
}
if (key->len > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"key is too long.");
return NULL;
}
if (msg->len > INT_MAX) {
PyErr_SetString(PyExc_OverflowError,
"msg is too long.");
return NULL;
}
Py_BEGIN_ALLOW_THREADS
result = HMAC(
evp,
(const void*)key->buf, (int)key->len,
(const unsigned char*)msg->buf, (int)msg->len,
md, &md_len
);
Py_END_ALLOW_THREADS
if (result == NULL) {
_setException(PyExc_ValueError);
return NULL;
}
return PyBytes_FromStringAndSize((const char*)md, md_len);
}
/* State for our callback function so that it can accumulate a result. */
typedef struct _internal_name_mapper_state {
PyObject *set;
int error;
} _InternalNameMapperState;
/* A callback function to pass to OpenSSL's OBJ_NAME_do_all(...) */
static void
_openssl_hash_name_mapper(const OBJ_NAME *openssl_obj_name, void *arg)
{
_InternalNameMapperState *state = (_InternalNameMapperState *)arg;
PyObject *py_name;
assert(state != NULL);
if (openssl_obj_name == NULL)
return;
/* Ignore aliased names, they pollute the list and OpenSSL appears to
* have its own definition of alias as the resulting list still
* contains duplicate and alternate names for several algorithms. */
if (openssl_obj_name->alias)
return;
py_name = PyUnicode_FromString(openssl_obj_name->name);
if (py_name == NULL) {
state->error = 1;
} else {
if (PySet_Add(state->set, py_name) != 0) {
state->error = 1;
}
Py_DECREF(py_name);
}
}
/* Ask OpenSSL for a list of supported ciphers, filling in a Python set. */
static PyObject*
generate_hash_name_list(void)
{
_InternalNameMapperState state;
state.set = PyFrozenSet_New(NULL);
if (state.set == NULL)
return NULL;
state.error = 0;
OBJ_NAME_do_all(OBJ_NAME_TYPE_MD_METH, &_openssl_hash_name_mapper, &state);
if (state.error) {
Py_DECREF(state.set);
return NULL;
}
return state.set;
}
/*
* This macro generates constructor function definitions for specific
* hash algorithms. These constructors are much faster than calling
* the generic one passing it a python string and are noticeably
* faster than calling a python new() wrapper. That is important for
* code that wants to make hashes of a bunch of small strings.
* The first call will lazy-initialize, which reports an exception
* if initialization fails.
*/
#define GEN_CONSTRUCTOR(NAME) \
static PyObject * \
EVP_new_ ## NAME (PyObject *self, PyObject *const *args, Py_ssize_t nargs) \
{ \
PyObject *data_obj = NULL; \
Py_buffer view = { 0 }; \
PyObject *ret_obj; \
\
if (!_PyArg_ParseStack(args, nargs, "|O:" #NAME , &data_obj)) { \
return NULL; \
} \
\
if (CONST_new_ ## NAME ## _ctx_p == NULL) { \
EVP_MD_CTX *ctx_p = EVP_MD_CTX_new(); \
if (!EVP_get_digestbyname(#NAME) || \
!EVP_DigestInit(ctx_p, EVP_get_digestbyname(#NAME))) { \
_setException(PyExc_ValueError); \
EVP_MD_CTX_free(ctx_p); \
return NULL; \
} \
CONST_new_ ## NAME ## _ctx_p = ctx_p; \
} \
\
if (data_obj) \
GET_BUFFER_VIEW_OR_ERROUT(data_obj, &view); \
\
ret_obj = EVPnew( \
CONST_ ## NAME ## _name_obj, \
NULL, \
CONST_new_ ## NAME ## _ctx_p, \
(unsigned char*)view.buf, \
view.len); \
\
if (data_obj) \
PyBuffer_Release(&view); \
return ret_obj; \
}
/* a PyMethodDef structure for the constructor */
#define CONSTRUCTOR_METH_DEF(NAME) \
{"openssl_" #NAME, (PyCFunction)(void(*)(void))EVP_new_ ## NAME, METH_FASTCALL, \
PyDoc_STR("Returns a " #NAME \
" hash object; optionally initialized with a string") \
}
/* used in the init function to setup a constructor: initialize OpenSSL
constructor constants if they haven't been initialized already. */
#define INIT_CONSTRUCTOR_CONSTANTS(NAME) do { \
if (CONST_ ## NAME ## _name_obj == NULL) { \
CONST_ ## NAME ## _name_obj = PyUnicode_FromString(#NAME); \
} \
} while (0);
GEN_CONSTRUCTOR(md5)
GEN_CONSTRUCTOR(sha1)
GEN_CONSTRUCTOR(sha224)
GEN_CONSTRUCTOR(sha256)
GEN_CONSTRUCTOR(sha384)
GEN_CONSTRUCTOR(sha512)
/* List of functions exported by this module */
static struct PyMethodDef EVP_functions[] = {
EVP_NEW_METHODDEF
#ifdef PY_PBKDF2_HMAC
PBKDF2_HMAC_METHODDEF
#endif
_HASHLIB_SCRYPT_METHODDEF
_HASHLIB_HMAC_DIGEST_METHODDEF
CONSTRUCTOR_METH_DEF(md5),
CONSTRUCTOR_METH_DEF(sha1),
CONSTRUCTOR_METH_DEF(sha224),
CONSTRUCTOR_METH_DEF(sha256),
CONSTRUCTOR_METH_DEF(sha384),
CONSTRUCTOR_METH_DEF(sha512),
{NULL, NULL} /* Sentinel */
};
/* Initialize this module. */
static struct PyModuleDef _hashlibmodule = {
PyModuleDef_HEAD_INIT,
"_hashlib",
NULL,
-1,
EVP_functions,
NULL,
NULL,
NULL,
NULL
};
PyMODINIT_FUNC
PyInit__hashlib(void)
{
PyObject *m, *openssl_md_meth_names;
#ifndef OPENSSL_VERSION_1_1
/* Load all digest algorithms and initialize cpuid */
OPENSSL_add_all_algorithms_noconf();
ERR_load_crypto_strings();
#endif
/* TODO build EVP_functions openssl_* entries dynamically based
* on what hashes are supported rather than listing many
* but having some be unsupported. Only init appropriate
* constants. */
Py_TYPE(&EVPtype) = &PyType_Type;
if (PyType_Ready(&EVPtype) < 0)
return NULL;
m = PyModule_Create(&_hashlibmodule);
if (m == NULL)
return NULL;
openssl_md_meth_names = generate_hash_name_list();
if (openssl_md_meth_names == NULL) {
Py_DECREF(m);
return NULL;
}
if (PyModule_AddObject(m, "openssl_md_meth_names", openssl_md_meth_names)) {
Py_DECREF(m);
return NULL;
}
Py_INCREF((PyObject *)&EVPtype);
PyModule_AddObject(m, "HASH", (PyObject *)&EVPtype);
/* these constants are used by the convenience constructors */
INIT_CONSTRUCTOR_CONSTANTS(md5);
INIT_CONSTRUCTOR_CONSTANTS(sha1);
INIT_CONSTRUCTOR_CONSTANTS(sha224);
INIT_CONSTRUCTOR_CONSTANTS(sha256);
INIT_CONSTRUCTOR_CONSTANTS(sha384);
INIT_CONSTRUCTOR_CONSTANTS(sha512);
return m;
}
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