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[3.6] bpo-31400: Improve SSL error handling on Windows (GH-3463) #3466

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Merged
tiran merged 1 commit into from
Sep 9, 2017
Merged

[3.6] bpo-31400: Improve SSL error handling on Windows (GH-3463) #3466

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1 change: 1 addition & 0 deletions Misc/NEWS.d/next/Library/2017-09-08-14-19-57.bpo-31400.YOTPKi.rst
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Original file line number Diff line number Diff line change
@@ -0,0 +1 @@
Improves SSL error handling to avoid losing error numbers.
57 changes: 47 additions & 10 deletions Modules/_ssl.c
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Original file line number Diff line number Diff line change
Expand Up @@ -302,6 +302,11 @@ typedef struct {
enum py_ssl_server_or_client socket_type;
PyObject *owner; /* Python level "owner" passed to servername callback */
PyObject *server_hostname;
int ssl_errno; /* last seen error from SSL */
int c_errno; /* last seen error from libc */
#ifdef MS_WINDOWS
int ws_errno; /* last seen error from winsock */
#endif
} PySSLSocket;

typedef struct {
Expand All @@ -321,6 +326,20 @@ static PyTypeObject PySSLSocket_Type;
static PyTypeObject PySSLMemoryBIO_Type;
static PyTypeObject PySSLSession_Type;

#ifdef MS_WINDOWS
#define _PySSL_UPDATE_ERRNO_IF(cond, sock, retcode) if (cond) { \
(sock)->ws_errno = WSAGetLastError(); \
(sock)->c_errno = errno; \
(sock)->ssl_errno = SSL_get_error((sock->ssl), (retcode)); \
} else { sock->ws_errno = 0; sock->c_errno = 0; sock->ssl_errno = 0; }
#else
#define _PySSL_UPDATE_ERRNO_IF(cond, sock, retcode) if (cond) { \
(sock)->c_errno = errno; \
(sock)->ssl_errno = SSL_get_error((sock->ssl), (retcode)); \
} else { (sock)->c_errno = 0; (sock)->ssl_errno = 0; }
#endif
#define _PySSL_UPDATE_ERRNO(sock, retcode) _PySSL_UPDATE_ERRNO_IF(1, (sock), (retcode))

/*[clinic input]
module _ssl
class _ssl._SSLContext "PySSLContext *" "&PySSLContext_Type"
Expand Down Expand Up @@ -494,7 +513,7 @@ PySSL_SetError(PySSLSocket *obj, int ret, const char *filename, int lineno)
e = ERR_peek_last_error();

if (obj->ssl != NULL) {
err = SSL_get_error(obj->ssl, ret);
err = obj->ssl_errno;

switch (err) {
case SSL_ERROR_ZERO_RETURN:
Expand Down Expand Up @@ -530,8 +549,16 @@ PySSL_SetError(PySSLSocket *obj, int ret, const char *filename, int lineno)
errstr = "EOF occurred in violation of protocol";
} else if (s && ret == -1) {
/* underlying BIO reported an I/O error */
Py_INCREF(s);
ERR_clear_error();
#ifdef MS_WINDOWS
if (obj->ws_errno)
return PyErr_SetFromWindowsErr(obj->ws_errno);
#endif
if (obj->c_errno) {
errno = obj->c_errno;
return PyErr_SetFromErrno(PyExc_OSError);
}
Py_INCREF(s);
s->errorhandler();
Py_DECREF(s);
return NULL;
Expand Down Expand Up @@ -609,6 +636,11 @@ newPySSLSocket(PySSLContext *sslctx, PySocketSockObject *sock,
}
self->server_hostname = hostname;
}
self->ssl_errno = 0;
self->c_errno = 0;
#ifdef MS_WINDOWS
self->ws_errno = 0;
#endif

/* Make sure the SSL error state is initialized */
(void) ERR_get_state();
Expand Down Expand Up @@ -706,8 +738,9 @@ _ssl__SSLSocket_do_handshake_impl(PySSLSocket *self)
do {
PySSL_BEGIN_ALLOW_THREADS
ret = SSL_do_handshake(self->ssl);
err = SSL_get_error(self->ssl, ret);
_PySSL_UPDATE_ERRNO_IF(ret < 1, self, ret);
PySSL_END_ALLOW_THREADS
err = self->ssl_errno;

if (PyErr_CheckSignals())
goto error;
Expand Down Expand Up @@ -2003,8 +2036,9 @@ _ssl__SSLSocket_write_impl(PySSLSocket *self, Py_buffer *b)
do {
PySSL_BEGIN_ALLOW_THREADS
len = SSL_write(self->ssl, b->buf, (int)b->len);
err = SSL_get_error(self->ssl, len);
_PySSL_UPDATE_ERRNO_IF(len <= 0, self, len);
PySSL_END_ALLOW_THREADS
err = self->ssl_errno;

if (PyErr_CheckSignals())
goto error;
Expand Down Expand Up @@ -2058,6 +2092,7 @@ _ssl__SSLSocket_pending_impl(PySSLSocket *self)

PySSL_BEGIN_ALLOW_THREADS
count = SSL_pending(self->ssl);
_PySSL_UPDATE_ERRNO_IF(count < 0, self, count);
PySSL_END_ALLOW_THREADS
if (count < 0)
return PySSL_SetError(self, count, __FILE__, __LINE__);
Expand Down Expand Up @@ -2146,7 +2181,7 @@ _ssl__SSLSocket_read_impl(PySSLSocket *self, int len, int group_right_1,
do {
PySSL_BEGIN_ALLOW_THREADS
count = SSL_read(self->ssl, mem, len);
err = SSL_get_error(self->ssl, count);
_PySSL_UPDATE_ERRNO_IF(count <= 0, self, count);
PySSL_END_ALLOW_THREADS

if (PyErr_CheckSignals())
Expand All @@ -2155,6 +2190,7 @@ _ssl__SSLSocket_read_impl(PySSLSocket *self, int len, int group_right_1,
if (has_timeout)
timeout = deadline - _PyTime_GetMonotonicClock();

err = self->ssl_errno;
if (err == SSL_ERROR_WANT_READ) {
sockstate = PySSL_select(sock, 0, timeout);
} else if (err == SSL_ERROR_WANT_WRITE) {
Expand Down Expand Up @@ -2211,7 +2247,7 @@ static PyObject *
_ssl__SSLSocket_shutdown_impl(PySSLSocket *self)
/*[clinic end generated code: output=ca1aa7ed9d25ca42 input=ede2cc1a2ddf0ee4]*/
{
int err, ssl_err, sockstate, nonblocking;
int err, sockstate, nonblocking;
int zeros = 0;
PySocketSockObject *sock = GET_SOCKET(self);
_PyTime_t timeout, deadline = 0;
Expand Down Expand Up @@ -2250,6 +2286,7 @@ _ssl__SSLSocket_shutdown_impl(PySSLSocket *self)
if (self->shutdown_seen_zero)
SSL_set_read_ahead(self->ssl, 0);
err = SSL_shutdown(self->ssl);
_PySSL_UPDATE_ERRNO_IF(err < 0, self, err);
PySSL_END_ALLOW_THREADS

/* If err == 1, a secure shutdown with SSL_shutdown() is complete */
Expand All @@ -2270,16 +2307,16 @@ _ssl__SSLSocket_shutdown_impl(PySSLSocket *self)
timeout = deadline - _PyTime_GetMonotonicClock();

/* Possibly retry shutdown until timeout or failure */
ssl_err = SSL_get_error(self->ssl, err);
if (ssl_err == SSL_ERROR_WANT_READ)
_PySSL_UPDATE_ERRNO(self, err);
if (self->ssl_errno == SSL_ERROR_WANT_READ)
sockstate = PySSL_select(sock, 0, timeout);
else if (ssl_err == SSL_ERROR_WANT_WRITE)
else if (self->ssl_errno == SSL_ERROR_WANT_WRITE)
sockstate = PySSL_select(sock, 1, timeout);
else
break;

if (sockstate == SOCKET_HAS_TIMED_OUT) {
if (ssl_err == SSL_ERROR_WANT_READ)
if (self->ssl_errno == SSL_ERROR_WANT_READ)
PyErr_SetString(PySocketModule.timeout_error,
"The read operation timed out");
else
Expand Down