/* 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" | |
#ifdef WITH_THREAD | |
#include "pythread.h" | |
#define ENTER_HASHLIB(obj) \ | |
if ((obj)->lock) { \ | |
if (!PyThread_acquire_lock((obj)->lock, 0)) { \ | |
Py_BEGIN_ALLOW_THREADS \ | |
PyThread_acquire_lock((obj)->lock, 1); \ | |
Py_END_ALLOW_THREADS \ | |
} \ | |
} | |
#define LEAVE_HASHLIB(obj) \ | |
if ((obj)->lock) { \ | |
PyThread_release_lock((obj)->lock); \ | |
} | |
#else | |
#define ENTER_HASHLIB(obj) | |
#define LEAVE_HASHLIB(obj) | |
#endif | |
/* EVP is the preferred interface to hashing in OpenSSL */ | |
#include <openssl/evp.h> | |
#define MUNCH_SIZE INT_MAX | |
/* TODO(gps): We should probably make this a module or EVPobject attribute | |
* to allow the user to optimize based on the platform they're using. */ | |
#define HASHLIB_GIL_MINSIZE 2048 | |
#ifndef HASH_OBJ_CONSTRUCTOR | |
#define HASH_OBJ_CONSTRUCTOR 0 | |
#endif | |
/* Minimum OpenSSL version needed to support sha224 and higher. */ | |
#if defined(OPENSSL_VERSION_NUMBER) && (OPENSSL_VERSION_NUMBER >= 0x00908000) | |
#define _OPENSSL_SUPPORTS_SHA2 | |
#endif | |
typedef struct { | |
PyObject_HEAD | |
PyObject *name; /* name of this hash algorithm */ | |
EVP_MD_CTX ctx; /* OpenSSL message digest context */ | |
#ifdef WITH_THREAD | |
PyThread_type_lock lock; /* OpenSSL context lock */ | |
#endif | |
} EVPobject; | |
static PyTypeObject EVPtype; | |
#define DEFINE_CONSTS_FOR_NEW(Name) \ | |
static PyObject *CONST_ ## Name ## _name_obj; \ | |
static EVP_MD_CTX CONST_new_ ## Name ## _ctx; \ | |
static EVP_MD_CTX *CONST_new_ ## Name ## _ctx_p = NULL; | |
DEFINE_CONSTS_FOR_NEW(md5) | |
DEFINE_CONSTS_FOR_NEW(sha1) | |
#ifdef _OPENSSL_SUPPORTS_SHA2 | |
DEFINE_CONSTS_FOR_NEW(sha224) | |
DEFINE_CONSTS_FOR_NEW(sha256) | |
DEFINE_CONSTS_FOR_NEW(sha384) | |
DEFINE_CONSTS_FOR_NEW(sha512) | |
#endif | |
static EVPobject * | |
newEVPobject(PyObject *name) | |
{ | |
EVPobject *retval = (EVPobject *)PyObject_New(EVPobject, &EVPtype); | |
/* save the name for .name to return */ | |
if (retval != NULL) { | |
Py_INCREF(name); | |
retval->name = name; | |
#ifdef WITH_THREAD | |
retval->lock = NULL; | |
#endif | |
} | |
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); | |
EVP_DigestUpdate(&self->ctx, (const void*)cp, process); | |
len -= process; | |
cp += process; | |
} | |
} | |
/* Internal methods for a hash object */ | |
static void | |
EVP_dealloc(EVPobject *self) | |
{ | |
#ifdef WITH_THREAD | |
if (self->lock != NULL) | |
PyThread_free_lock(self->lock); | |
#endif | |
EVP_MD_CTX_cleanup(&self->ctx); | |
Py_XDECREF(self->name); | |
PyObject_Del(self); | |
} | |
static void locked_EVP_MD_CTX_copy(EVP_MD_CTX *new_ctx_p, EVPobject *self) | |
{ | |
ENTER_HASHLIB(self); | |
EVP_MD_CTX_copy(new_ctx_p, &self->ctx); | |
LEAVE_HASHLIB(self); | |
} | |
/* External methods for a hash object */ | |
PyDoc_STRVAR(EVP_copy__doc__, "Return a copy of the hash object."); | |
static PyObject * | |
EVP_copy(EVPobject *self, PyObject *unused) | |
{ | |
EVPobject *newobj; | |
if ( (newobj = newEVPobject(self->name))==NULL) | |
return NULL; | |
locked_EVP_MD_CTX_copy(&newobj->ctx, self); | |
return (PyObject *)newobj; | |
} | |
PyDoc_STRVAR(EVP_digest__doc__, | |
"Return the digest value as a string of binary data."); | |
static PyObject * | |
EVP_digest(EVPobject *self, PyObject *unused) | |
{ | |
unsigned char digest[EVP_MAX_MD_SIZE]; | |
EVP_MD_CTX temp_ctx; | |
PyObject *retval; | |
unsigned int digest_size; | |
locked_EVP_MD_CTX_copy(&temp_ctx, self); | |
digest_size = EVP_MD_CTX_size(&temp_ctx); | |
EVP_DigestFinal(&temp_ctx, digest, NULL); | |
retval = PyString_FromStringAndSize((const char *)digest, digest_size); | |
EVP_MD_CTX_cleanup(&temp_ctx); | |
return retval; | |
} | |
PyDoc_STRVAR(EVP_hexdigest__doc__, | |
"Return the digest value as a string of hexadecimal digits."); | |
static PyObject * | |
EVP_hexdigest(EVPobject *self, PyObject *unused) | |
{ | |
unsigned char digest[EVP_MAX_MD_SIZE]; | |
EVP_MD_CTX temp_ctx; | |
PyObject *retval; | |
char *hex_digest; | |
unsigned int i, j, digest_size; | |
/* Get the raw (binary) digest value */ | |
locked_EVP_MD_CTX_copy(&temp_ctx, self); | |
digest_size = EVP_MD_CTX_size(&temp_ctx); | |
EVP_DigestFinal(&temp_ctx, digest, NULL); | |
EVP_MD_CTX_cleanup(&temp_ctx); | |
/* Create a new string */ | |
/* NOTE: not thread safe! modifying an already created string object */ | |
/* (not a problem because we hold the GIL by default) */ | |
retval = PyString_FromStringAndSize(NULL, digest_size * 2); | |
if (!retval) | |
return NULL; | |
hex_digest = PyString_AsString(retval); | |
if (!hex_digest) { | |
Py_DECREF(retval); | |
return NULL; | |
} | |
/* Make hex version of the digest */ | |
for(i=j=0; i<digest_size; i++) { | |
char c; | |
c = (digest[i] >> 4) & 0xf; | |
c = (c>9) ? c+'a'-10 : c + '0'; | |
hex_digest[j++] = c; | |
c = (digest[i] & 0xf); | |
c = (c>9) ? c+'a'-10 : c + '0'; | |
hex_digest[j++] = c; | |
} | |
return retval; | |
} | |
PyDoc_STRVAR(EVP_update__doc__, | |
"Update this hash object's state with the provided string."); | |
static PyObject * | |
EVP_update(EVPobject *self, PyObject *args) | |
{ | |
Py_buffer view; | |
if (!PyArg_ParseTuple(args, "s*:update", &view)) | |
return NULL; | |
#ifdef WITH_THREAD | |
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 | |
#endif | |
{ | |
EVP_hash(self, view.buf, view.len); | |
} | |
PyBuffer_Release(&view); | |
Py_RETURN_NONE; | |
} | |
static PyMethodDef EVP_methods[] = { | |
{"update", (PyCFunction)EVP_update, METH_VARARGS, EVP_update__doc__}, | |
{"digest", (PyCFunction)EVP_digest, METH_NOARGS, EVP_digest__doc__}, | |
{"hexdigest", (PyCFunction)EVP_hexdigest, METH_NOARGS, EVP_hexdigest__doc__}, | |
{"copy", (PyCFunction)EVP_copy, METH_NOARGS, EVP_copy__doc__}, | |
{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}, | |
/* the old md5 and sha modules support 'digest_size' as in PEP 247. | |
* the old sha module also supported 'digestsize'. ugh. */ | |
{"digestsize", | |
(getter)EVP_get_digest_size, NULL, | |
NULL, | |
NULL}, | |
{NULL} /* Sentinel */ | |
}; | |
static PyObject * | |
EVP_repr(PyObject *self) | |
{ | |
char buf[100]; | |
PyOS_snprintf(buf, sizeof(buf), "<%s HASH object @ %p>", | |
PyString_AsString(((EVPobject *)self)->name), self); | |
return PyString_FromString(buf); | |
} | |
#if HASH_OBJ_CONSTRUCTOR | |
static int | |
EVP_tp_init(EVPobject *self, PyObject *args, PyObject *kwds) | |
{ | |
static char *kwlist[] = {"name", "string", NULL}; | |
PyObject *name_obj = NULL; | |
Py_buffer view = { 0 }; | |
char *nameStr; | |
const EVP_MD *digest; | |
if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|s*:HASH", kwlist, | |
&name_obj, &view)) { | |
return -1; | |
} | |
if (!PyArg_Parse(name_obj, "s", &nameStr)) { | |
PyErr_SetString(PyExc_TypeError, "name must be a string"); | |
PyBuffer_Release(&view); | |
return -1; | |
} | |
digest = EVP_get_digestbyname(nameStr); | |
if (!digest) { | |
PyErr_SetString(PyExc_ValueError, "unknown hash function"); | |
PyBuffer_Release(&view); | |
return -1; | |
} | |
EVP_DigestInit(&self->ctx, digest); | |
self->name = name_obj; | |
Py_INCREF(self->name); | |
if (view.obj) { | |
if (view.len >= HASHLIB_GIL_MINSIZE) { | |
Py_BEGIN_ALLOW_THREADS | |
EVP_hash(self, view.buf, view.len); | |
Py_END_ALLOW_THREADS | |
} else { | |
EVP_hash(self, view.buf, view.len); | |
} | |
PyBuffer_Release(&view); | |
} | |
return 0; | |
} | |
#endif | |
PyDoc_STRVAR(hashtype_doc, | |
"A hash represents the object used to calculate a checksum of a\n\ | |
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\n"); | |
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_compare*/ | |
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 */ | |
#if 1 | |
0, /* tp_base */ | |
0, /* tp_dict */ | |
0, /* tp_descr_get */ | |
0, /* tp_descr_set */ | |
0, /* tp_dictoffset */ | |
#endif | |
#if HASH_OBJ_CONSTRUCTOR | |
(initproc)EVP_tp_init, /* tp_init */ | |
#endif | |
}; | |
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 { | |
EVP_DigestInit(&self->ctx, digest); | |
} | |
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() */ | |
PyDoc_STRVAR(EVP_new__doc__, | |
"Return a new hash object using the named algorithm.\n\ | |
An optional string argument may be provided and will be\n\ | |
automatically hashed.\n\ | |
\n\ | |
The MD5 and SHA1 algorithms are always supported.\n"); | |
static PyObject * | |
EVP_new(PyObject *self, PyObject *args, PyObject *kwdict) | |
{ | |
static char *kwlist[] = {"name", "string", NULL}; | |
PyObject *name_obj = NULL; | |
Py_buffer view = { 0 }; | |
PyObject *ret_obj; | |
char *name; | |
const EVP_MD *digest; | |
if (!PyArg_ParseTupleAndKeywords(args, kwdict, "O|s*:new", kwlist, | |
&name_obj, &view)) { | |
return NULL; | |
} | |
if (!PyArg_Parse(name_obj, "s", &name)) { | |
PyErr_SetString(PyExc_TypeError, "name must be a string"); | |
return NULL; | |
} | |
digest = EVP_get_digestbyname(name); | |
ret_obj = EVPnew(name_obj, digest, NULL, (unsigned char*)view.buf, | |
view.len); | |
PyBuffer_Release(&view); | |
return ret_obj; | |
} | |
/* | |
* 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 noticably | |
* faster than calling a python new() wrapper. Thats important for | |
* code that wants to make hashes of a bunch of small strings. | |
*/ | |
#define GEN_CONSTRUCTOR(NAME) \ | |
static PyObject * \ | |
EVP_new_ ## NAME (PyObject *self, PyObject *args) \ | |
{ \ | |
Py_buffer view = { 0 }; \ | |
PyObject *ret_obj; \ | |
\ | |
if (!PyArg_ParseTuple(args, "|s*:" #NAME , &view)) { \ | |
return NULL; \ | |
} \ | |
\ | |
ret_obj = EVPnew( \ | |
CONST_ ## NAME ## _name_obj, \ | |
NULL, \ | |
CONST_new_ ## NAME ## _ctx_p, \ | |
(unsigned char*)view.buf, view.len); \ | |
PyBuffer_Release(&view); \ | |
return ret_obj; \ | |
} | |
/* a PyMethodDef structure for the constructor */ | |
#define CONSTRUCTOR_METH_DEF(NAME) \ | |
{"openssl_" #NAME, (PyCFunction)EVP_new_ ## NAME, METH_VARARGS, \ | |
PyDoc_STR("Returns a " #NAME \ | |
" hash object; optionally initialized with a string") \ | |
} | |
/* used in the init function to setup a constructor */ | |
#define INIT_CONSTRUCTOR_CONSTANTS(NAME) do { \ | |
CONST_ ## NAME ## _name_obj = PyString_FromString(#NAME); \ | |
if (EVP_get_digestbyname(#NAME)) { \ | |
CONST_new_ ## NAME ## _ctx_p = &CONST_new_ ## NAME ## _ctx; \ | |
EVP_DigestInit(CONST_new_ ## NAME ## _ctx_p, EVP_get_digestbyname(#NAME)); \ | |
} \ | |
} while (0); | |
GEN_CONSTRUCTOR(md5) | |
GEN_CONSTRUCTOR(sha1) | |
#ifdef _OPENSSL_SUPPORTS_SHA2 | |
GEN_CONSTRUCTOR(sha224) | |
GEN_CONSTRUCTOR(sha256) | |
GEN_CONSTRUCTOR(sha384) | |
GEN_CONSTRUCTOR(sha512) | |
#endif | |
/* List of functions exported by this module */ | |
static struct PyMethodDef EVP_functions[] = { | |
{"new", (PyCFunction)EVP_new, METH_VARARGS|METH_KEYWORDS, EVP_new__doc__}, | |
CONSTRUCTOR_METH_DEF(md5), | |
CONSTRUCTOR_METH_DEF(sha1), | |
#ifdef _OPENSSL_SUPPORTS_SHA2 | |
CONSTRUCTOR_METH_DEF(sha224), | |
CONSTRUCTOR_METH_DEF(sha256), | |
CONSTRUCTOR_METH_DEF(sha384), | |
CONSTRUCTOR_METH_DEF(sha512), | |
#endif | |
{NULL, NULL} /* Sentinel */ | |
}; | |
/* Initialize this module. */ | |
PyMODINIT_FUNC | |
init_hashlib(void) | |
{ | |
PyObject *m; | |
OpenSSL_add_all_digests(); | |
/* 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; | |
m = Py_InitModule("_hashlib", EVP_functions); | |
if (m == NULL) | |
return; | |
#if HASH_OBJ_CONSTRUCTOR | |
Py_INCREF(&EVPtype); | |
PyModule_AddObject(m, "HASH", (PyObject *)&EVPtype); | |
#endif | |
/* these constants are used by the convenience constructors */ | |
INIT_CONSTRUCTOR_CONSTANTS(md5); | |
INIT_CONSTRUCTOR_CONSTANTS(sha1); | |
#ifdef _OPENSSL_SUPPORTS_SHA2 | |
INIT_CONSTRUCTOR_CONSTANTS(sha224); | |
INIT_CONSTRUCTOR_CONSTANTS(sha256); | |
INIT_CONSTRUCTOR_CONSTANTS(sha384); | |
INIT_CONSTRUCTOR_CONSTANTS(sha512); | |
#endif | |
} |