cpython/Modules/_ssl/debughelpers.c

220 lines
6.4 KiB
C

/* Debug helpers */
#ifndef SSL3_MT_CHANGE_CIPHER_SPEC
/* Dummy message type for handling CCS like a normal handshake message
* not defined in OpenSSL 1.0.2
*/
#define SSL3_MT_CHANGE_CIPHER_SPEC 0x0101
#endif
static void
_PySSL_msg_callback(int write_p, int version, int content_type,
const void *buf, size_t len, SSL *ssl, void *arg)
{
const char *cbuf = (const char *)buf;
PyGILState_STATE threadstate;
PyObject *res = NULL;
PySSLSocket *ssl_obj = NULL; /* ssl._SSLSocket, borrowed ref */
PyObject *ssl_socket = NULL; /* ssl.SSLSocket or ssl.SSLObject */
int msg_type;
threadstate = PyGILState_Ensure();
ssl_obj = (PySSLSocket *)SSL_get_app_data(ssl);
assert(Py_IS_TYPE(ssl_obj, get_state_sock(ssl_obj)->PySSLSocket_Type));
if (ssl_obj->ctx->msg_cb == NULL) {
PyGILState_Release(threadstate);
return;
}
if (ssl_obj->owner)
ssl_socket = PyWeakref_GetObject(ssl_obj->owner);
else if (ssl_obj->Socket)
ssl_socket = PyWeakref_GetObject(ssl_obj->Socket);
else
ssl_socket = (PyObject *)ssl_obj;
Py_INCREF(ssl_socket);
/* assume that OpenSSL verifies all payload and buf len is of sufficient
length */
switch(content_type) {
case SSL3_RT_CHANGE_CIPHER_SPEC:
msg_type = SSL3_MT_CHANGE_CIPHER_SPEC;
break;
case SSL3_RT_ALERT:
/* byte 0: level */
/* byte 1: alert type */
msg_type = (int)cbuf[1];
break;
case SSL3_RT_HANDSHAKE:
msg_type = (int)cbuf[0];
break;
#ifdef SSL3_RT_HEADER
case SSL3_RT_HEADER:
/* frame header encodes version in bytes 1..2 */
version = cbuf[1] << 8 | cbuf[2];
msg_type = (int)cbuf[0];
break;
#endif
#ifdef SSL3_RT_INNER_CONTENT_TYPE
case SSL3_RT_INNER_CONTENT_TYPE:
msg_type = (int)cbuf[0];
break;
#endif
default:
/* never SSL3_RT_APPLICATION_DATA */
msg_type = -1;
break;
}
res = PyObject_CallFunction(
ssl_obj->ctx->msg_cb, "Osiiiy#",
ssl_socket, write_p ? "write" : "read",
version, content_type, msg_type,
buf, len
);
if (res == NULL) {
PyErr_Fetch(&ssl_obj->exc_type, &ssl_obj->exc_value, &ssl_obj->exc_tb);
} else {
Py_DECREF(res);
}
Py_XDECREF(ssl_socket);
PyGILState_Release(threadstate);
}
static PyObject *
_PySSLContext_get_msg_callback(PySSLContext *self, void *c) {
if (self->msg_cb != NULL) {
Py_INCREF(self->msg_cb);
return self->msg_cb;
} else {
Py_RETURN_NONE;
}
}
static int
_PySSLContext_set_msg_callback(PySSLContext *self, PyObject *arg, void *c) {
Py_CLEAR(self->msg_cb);
if (arg == Py_None) {
SSL_CTX_set_msg_callback(self->ctx, NULL);
}
else {
if (!PyCallable_Check(arg)) {
SSL_CTX_set_msg_callback(self->ctx, NULL);
PyErr_SetString(PyExc_TypeError,
"not a callable object");
return -1;
}
Py_INCREF(arg);
self->msg_cb = arg;
SSL_CTX_set_msg_callback(self->ctx, _PySSL_msg_callback);
}
return 0;
}
static void
_PySSL_keylog_callback(const SSL *ssl, const char *line)
{
PyGILState_STATE threadstate;
PySSLSocket *ssl_obj = NULL; /* ssl._SSLSocket, borrowed ref */
int res, e;
static PyThread_type_lock *lock = NULL;
threadstate = PyGILState_Ensure();
ssl_obj = (PySSLSocket *)SSL_get_app_data(ssl);
assert(Py_IS_TYPE(ssl_obj, get_state_sock(ssl_obj)->PySSLSocket_Type));
if (ssl_obj->ctx->keylog_bio == NULL) {
return;
}
/* Allocate a static lock to synchronize writes to keylog file.
* The lock is neither released on exit nor on fork(). The lock is
* also shared between all SSLContexts although contexts may write to
* their own files. IMHO that's good enough for a non-performance
* critical debug helper.
*/
if (lock == NULL) {
lock = PyThread_allocate_lock();
if (lock == NULL) {
PyErr_SetString(PyExc_MemoryError, "Unable to allocate lock");
PyErr_Fetch(&ssl_obj->exc_type, &ssl_obj->exc_value,
&ssl_obj->exc_tb);
return;
}
}
PySSL_BEGIN_ALLOW_THREADS
PyThread_acquire_lock(lock, 1);
res = BIO_printf(ssl_obj->ctx->keylog_bio, "%s\n", line);
e = errno;
(void)BIO_flush(ssl_obj->ctx->keylog_bio);
PyThread_release_lock(lock);
PySSL_END_ALLOW_THREADS
if (res == -1) {
errno = e;
PyErr_SetFromErrnoWithFilenameObject(PyExc_OSError,
ssl_obj->ctx->keylog_filename);
PyErr_Fetch(&ssl_obj->exc_type, &ssl_obj->exc_value, &ssl_obj->exc_tb);
}
PyGILState_Release(threadstate);
}
static PyObject *
_PySSLContext_get_keylog_filename(PySSLContext *self, void *c) {
if (self->keylog_filename != NULL) {
Py_INCREF(self->keylog_filename);
return self->keylog_filename;
} else {
Py_RETURN_NONE;
}
}
static int
_PySSLContext_set_keylog_filename(PySSLContext *self, PyObject *arg, void *c) {
FILE *fp;
/* Reset variables and callback first */
SSL_CTX_set_keylog_callback(self->ctx, NULL);
Py_CLEAR(self->keylog_filename);
if (self->keylog_bio != NULL) {
BIO *bio = self->keylog_bio;
self->keylog_bio = NULL;
PySSL_BEGIN_ALLOW_THREADS
BIO_free_all(bio);
PySSL_END_ALLOW_THREADS
}
if (arg == Py_None) {
/* None disables the callback */
return 0;
}
/* _Py_fopen_obj() also checks that arg is of proper type. */
fp = _Py_fopen_obj(arg, "a" PY_STDIOTEXTMODE);
if (fp == NULL)
return -1;
self->keylog_bio = BIO_new_fp(fp, BIO_CLOSE | BIO_FP_TEXT);
if (self->keylog_bio == NULL) {
PyErr_SetString(get_state_ctx(self)->PySSLErrorObject,
"Can't malloc memory for keylog file");
return -1;
}
Py_INCREF(arg);
self->keylog_filename = arg;
/* Write a header for seekable, empty files (this excludes pipes). */
PySSL_BEGIN_ALLOW_THREADS
if (BIO_tell(self->keylog_bio) == 0) {
BIO_puts(self->keylog_bio,
"# TLS secrets log file, generated by OpenSSL / Python\n");
(void)BIO_flush(self->keylog_bio);
}
PySSL_END_ALLOW_THREADS
SSL_CTX_set_keylog_callback(self->ctx, _PySSL_keylog_callback);
return 0;
}