/*
* Copyright (c) 2008-2024 Jonathan Schleifer <js@nil.im>
*
* All rights reserved.
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version 3.0 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* version 3.0 for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* version 3.0 along with this program. If not, see
* <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <errno.h>
#import "OFGnuTLSTLSStream.h"
#import "OFData.h"
#import "OFAlreadyOpenException.h"
#import "OFInitializationFailedException.h"
#import "OFNotOpenException.h"
#import "OFReadFailedException.h"
#import "OFTLSHandshakeFailedException.h"
#import "OFWriteFailedException.h"
int _ObjFWTLS_reference;
static gnutls_certificate_credentials_t systemTrustCreds;
#ifndef GNUTLS_SAFE_PADDING_CHECK
/* Some older versions don't have it. */
# define GNUTLS_SAFE_PADDING_CHECK 0
#endif
@implementation OFGnuTLSTLSStream
static ssize_t
readFunc(gnutls_transport_ptr_t transport, void *buffer, size_t length)
{
OFGnuTLSTLSStream *stream = (OFGnuTLSTLSStream *)transport;
@try {
length = [stream.underlyingStream readIntoBuffer: buffer
length: length];
} @catch (OFReadFailedException *e) {
gnutls_transport_set_errno(stream->_session, e.errNo);
return -1;
}
if (length == 0 && !stream.underlyingStream.atEndOfStream) {
gnutls_transport_set_errno(stream->_session, EAGAIN);
return -1;
}
return length;
}
static ssize_t
writeFunc(gnutls_transport_ptr_t transport, const void *buffer, size_t length)
{
OFGnuTLSTLSStream *stream = (OFGnuTLSTLSStream *)transport;
@try {
[stream.underlyingStream writeBuffer: buffer length: length];
} @catch (OFWriteFailedException *e) {
gnutls_transport_set_errno(stream->_session, e.errNo);
if (e.errNo == EWOULDBLOCK || e.errNo == EAGAIN)
return e.bytesWritten;
return -1;
}
return length;
}
+ (void)load
{
if (OFTLSStreamImplementation == Nil)
OFTLSStreamImplementation = self;
}
+ (void)initialize
{
if (self != [OFGnuTLSTLSStream class])
return;
if (gnutls_certificate_allocate_credentials(&systemTrustCreds) !=
GNUTLS_E_SUCCESS ||
gnutls_certificate_set_x509_system_trust(systemTrustCreds) < 0)
@throw [OFInitializationFailedException exception];
}
- (instancetype)initWithStream: (OFStream <OFReadyForReadingObserving,
OFReadyForWritingObserving> *)stream
{
self = [super initWithStream: stream];
@try {
_underlyingStream.delegate = self;
} @catch (id e) {
[self release];
@throw e;
}
return self;
}
- (void)dealloc
{
if (_initialized)
[self close];
[_host release];
[super dealloc];
}
- (void)close
{
if (!_initialized)
@throw [OFNotOpenException exceptionWithObject: self];
if (_handshakeDone)
gnutls_bye(_session, GNUTLS_SHUT_WR);
gnutls_deinit(_session);
_initialized = _handshakeDone = false;
[_host release];
_host = nil;
[super close];
}
- (size_t)lowlevelReadIntoBuffer: (void *)buffer length: (size_t)length
{
ssize_t ret;
if (!_handshakeDone)
@throw [OFNotOpenException exceptionWithObject: self];
if ((ret = gnutls_record_recv(_session, buffer, length)) < 0) {
/*
* The underlying stream might have had data ready, but not
* enough for GnuTLS to return decrypted data. This means the
* caller might have observed the TLS stream for reading, got a
* ready signal and read - and expects the read to succeed, not
* to fail with EWOULDBLOCK/EAGAIN, as it was signaled ready.
* Therefore, return 0, as we could read 0 decrypted bytes, but
* cleared the ready signal of the underlying stream.
*/
if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN)
return 0;
/* FIXME: Translate error to errNo */
@throw [OFReadFailedException exceptionWithObject: self
requestedLength: length
errNo: 0];
}
return ret;
}
- (size_t)lowlevelWriteBuffer: (const void *)buffer length: (size_t)length
{
ssize_t ret;
if (!_handshakeDone)
@throw [OFNotOpenException exceptionWithObject: self];
if ((ret = gnutls_record_send(_session, buffer, length)) < 0) {
if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN)
return 0;
/* FIXME: Translate error to errNo */
@throw [OFWriteFailedException exceptionWithObject: self
requestedLength: length
bytesWritten: ret
errNo: 0];
}
return ret;
}
- (bool)lowlevelHasDataInReadBuffer
{
return (_underlyingStream.hasDataInReadBuffer ||
gnutls_record_check_pending(_session) > 0);
}
- (void)asyncPerformClientHandshakeWithHost: (OFString *)host
runLoopMode: (OFRunLoopMode)runLoopMode
{
static const OFTLSStreamErrorCode initFailedErrorCode =
OFTLSStreamErrorCodeInitializationFailed;
void *pool = objc_autoreleasePoolPush();
id exception = nil;
int status;
if (_initialized)
@throw [OFAlreadyOpenException exceptionWithObject: self];
if (gnutls_init(&_session, GNUTLS_CLIENT | GNUTLS_NONBLOCK |
GNUTLS_SAFE_PADDING_CHECK) != GNUTLS_E_SUCCESS)
@throw [OFTLSHandshakeFailedException
exceptionWithStream: self
host: host
errorCode: initFailedErrorCode];
_initialized = true;
gnutls_transport_set_ptr(_session, self);
gnutls_transport_set_pull_function(_session, readFunc);
gnutls_transport_set_push_function(_session, writeFunc);
if (gnutls_set_default_priority(_session) != GNUTLS_E_SUCCESS ||
gnutls_credentials_set(_session, GNUTLS_CRD_CERTIFICATE,
systemTrustCreds) != GNUTLS_E_SUCCESS)
@throw [OFTLSHandshakeFailedException
exceptionWithStream: self
host: host
errorCode: initFailedErrorCode];
_host = [host copy];
if (gnutls_server_name_set(_session, GNUTLS_NAME_DNS,
_host.UTF8String, _host.UTF8StringLength) != GNUTLS_E_SUCCESS)
@throw [OFTLSHandshakeFailedException
exceptionWithStream: self
host: host
errorCode: initFailedErrorCode];
if (_verifiesCertificates)
gnutls_session_set_verify_cert(_session, _host.UTF8String, 0);
status = gnutls_handshake(_session);
if (status == GNUTLS_E_INTERRUPTED || status == GNUTLS_E_AGAIN) {
if (gnutls_record_get_direction(_session) == 1)
[_underlyingStream asyncWriteData: [OFData data]
runLoopMode: runLoopMode];
else
[_underlyingStream asyncReadIntoBuffer: (void *)""
length: 0
runLoopMode: runLoopMode];
[_delegate retain];
objc_autoreleasePoolPop(pool);
return;
}
if (status == GNUTLS_E_SUCCESS)
_handshakeDone = true;
else
/* FIXME: Map to better errors */
exception = [OFTLSHandshakeFailedException
exceptionWithStream: self
host: host
errorCode: OFTLSStreamErrorCodeUnknown];
if ([_delegate respondsToSelector:
@selector(stream:didPerformClientHandshakeWithHost:exception:)])
[_delegate stream: self
didPerformClientHandshakeWithHost: host
exception: exception];
objc_autoreleasePoolPop(pool);
}
- (bool)stream: (OFStream *)stream
didReadIntoBuffer: (void *)buffer
length: (size_t)length
exception: (id)exception
{
if (exception == nil) {
int status = gnutls_handshake(_session);
if (status == GNUTLS_E_INTERRUPTED ||
status == GNUTLS_E_AGAIN) {
if (gnutls_record_get_direction(_session) == 1) {
OFRunLoopMode runLoopMode =
[OFRunLoop currentRunLoop].currentMode;
[_underlyingStream asyncWriteData: [OFData data]
runLoopMode: runLoopMode];
return false;
} else
return true;
}
if (status == GNUTLS_E_SUCCESS)
_handshakeDone = true;
else
exception = [OFTLSHandshakeFailedException
exceptionWithStream: self
host: _host
errorCode: OFTLSStreamErrorCodeUnknown];
}
if ([_delegate respondsToSelector:
@selector(stream:didPerformClientHandshakeWithHost:exception:)])
[_delegate stream: self
didPerformClientHandshakeWithHost: _host
exception: exception];
[_delegate release];
return false;
}
- (OFData *)stream: (OFStream *)stream
didWriteData: (OFData *)data
bytesWritten: (size_t)bytesWritten
exception: (id)exception
{
if (exception == nil) {
int status = gnutls_handshake(_session);
if (status == GNUTLS_E_INTERRUPTED ||
status == GNUTLS_E_AGAIN) {
if (gnutls_record_get_direction(_session) == 1)
return data;
else {
OFRunLoopMode runLoopMode =
[OFRunLoop currentRunLoop].currentMode;
[_underlyingStream
asyncReadIntoBuffer: (void *)""
length: 0
runLoopMode: runLoopMode];
return nil;
}
}
if (status == GNUTLS_E_SUCCESS)
_handshakeDone = true;
else
exception = [OFTLSHandshakeFailedException
exceptionWithStream: self
host: _host
errorCode: OFTLSStreamErrorCodeUnknown];
}
if ([_delegate respondsToSelector:
@selector(stream:didPerformClientHandshakeWithHost:exception:)])
[_delegate stream: self
didPerformClientHandshakeWithHost: _host
exception: exception];
[_delegate release];
return nil;
}
@end