BadVPN – Rev 1
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/**
* @file PeerChat.c
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <string.h>
#include <nss/ssl.h>
#include <nss/sslerr.h>
#include <misc/byteorder.h>
#include <security/BRandom.h>
#include "PeerChat.h"
#include <generated/blog_channel_PeerChat.h>
#define PeerLog(_o, ...) BLog_LogViaFunc((_o)->logfunc, (_o)->user, BLOG_CURRENT_CHANNEL, __VA_ARGS__)
static void report_error (PeerChat *o)
{
DebugError_AssertNoError(&o->d_err);
DEBUGERROR(&o->d_err, o->handler_error(o->user))
return;
}
static void recv_job_handler (PeerChat *o)
{
DebugObject_Access(&o->d_obj);
DebugError_AssertNoError(&o->d_err);
ASSERT(o->recv_data_len >= 0)
ASSERT(o->recv_data_len <= SC_MAX_MSGLEN)
int data_len = o->recv_data_len;
// set no received data
o->recv_data_len = -1;
#ifdef PEERCHAT_SIMULATE_ERROR
uint8_t x;
BRandom_randomize(&x, sizeof(x));
if (x < PEERCHAT_SIMULATE_ERROR) {
PeerLog(o, BLOG_ERROR, "simulate error");
report_error(o);
return;
}
#endif
if (o->ssl_mode != PEERCHAT_SSL_NONE) {
// buffer data
if (!SimpleStreamBuffer_Write(&o->ssl_recv_buf, o->recv_data, data_len)) {
PeerLog(o, BLOG_ERROR, "out of recv buffer");
report_error(o);
return;
}
} else {
// call message handler
o->handler_message(o->user, o->recv_data, data_len);
return;
}
}
static void ssl_con_handler (PeerChat *o, int event)
{
DebugObject_Access(&o->d_obj);
DebugError_AssertNoError(&o->d_err);
ASSERT(o->ssl_mode == PEERCHAT_SSL_CLIENT || o->ssl_mode == PEERCHAT_SSL_SERVER)
ASSERT(event == BSSLCONNECTION_EVENT_ERROR)
PeerLog(o, BLOG_ERROR, "SSL error");
report_error(o);
return;
}
static SECStatus client_auth_data_callback (PeerChat *o, PRFileDesc *fd, CERTDistNames *caNames, CERTCertificate **pRetCert, SECKEYPrivateKey **pRetKey)
{
DebugObject_Access(&o->d_obj);
ASSERT(o->ssl_mode == PEERCHAT_SSL_CLIENT)
CERTCertificate *cert = CERT_DupCertificate(o->ssl_cert);
if (!cert) {
PeerLog(o, BLOG_ERROR, "CERT_DupCertificate failed");
goto fail0;
}
SECKEYPrivateKey *key = SECKEY_CopyPrivateKey(o->ssl_key);
if (!key) {
PeerLog(o, BLOG_ERROR, "SECKEY_CopyPrivateKey failed");
goto fail1;
}
*pRetCert = cert;
*pRetKey = key;
return SECSuccess;
fail1:
CERT_DestroyCertificate(cert);
fail0:
return SECFailure;
}
static SECStatus auth_certificate_callback (PeerChat *o, PRFileDesc *fd, PRBool checkSig, PRBool isServer)
{
DebugObject_Access(&o->d_obj);
ASSERT(o->ssl_mode == PEERCHAT_SSL_CLIENT || o->ssl_mode == PEERCHAT_SSL_SERVER)
// This callback is used to bypass checking the server's domain name, as peers
// don't have domain names. We byte-compare the certificate to the one reported
// by the server anyway.
SECStatus ret = SECFailure;
CERTCertificate *cert = SSL_PeerCertificate(o->ssl_prfd);
if (!cert) {
PeerLog(o, BLOG_ERROR, "SSL_PeerCertificate failed");
PORT_SetError(SSL_ERROR_BAD_CERTIFICATE);
goto fail1;
}
SECCertUsage cert_usage = (o->ssl_mode == PEERCHAT_SSL_CLIENT ? certUsageSSLServer : certUsageSSLClient);
if (CERT_VerifyCertNow(CERT_GetDefaultCertDB(), cert, PR_TRUE, cert_usage, SSL_RevealPinArg(o->ssl_prfd)) != SECSuccess) {
goto fail2;
}
// compare to certificate provided by the server
SECItem der = cert->derCert;
if (der.len != o->ssl_peer_cert_len || memcmp(der.data, o->ssl_peer_cert, der.len)) {
PeerLog(o, BLOG_ERROR, "peer certificate doesn't match");
PORT_SetError(SSL_ERROR_BAD_CERTIFICATE);
goto fail2;
}
ret = SECSuccess;
fail2:
CERT_DestroyCertificate(cert);
fail1:
return ret;
}
static void ssl_recv_if_handler_send (PeerChat *o, uint8_t *data, int data_len)
{
DebugObject_Access(&o->d_obj);
DebugError_AssertNoError(&o->d_err);
ASSERT(o->ssl_mode == PEERCHAT_SSL_CLIENT || o->ssl_mode == PEERCHAT_SSL_SERVER)
ASSERT(data_len >= 0)
ASSERT(data_len <= SC_MAX_MSGLEN)
// accept packet
PacketPassInterface_Done(&o->ssl_recv_if);
// call message handler
o->handler_message(o->user, data, data_len);
return;
}
static void ssl_recv_decoder_handler_error (PeerChat *o)
{
DebugObject_Access(&o->d_obj);
DebugError_AssertNoError(&o->d_err);
ASSERT(o->ssl_mode == PEERCHAT_SSL_CLIENT || o->ssl_mode == PEERCHAT_SSL_SERVER)
PeerLog(o, BLOG_ERROR, "decoder error");
report_error(o);
return;
}
int PeerChat_Init (PeerChat *o, peerid_t peer_id, int ssl_mode, int ssl_flags, CERTCertificate *ssl_cert, SECKEYPrivateKey *ssl_key,
uint8_t *ssl_peer_cert, int ssl_peer_cert_len, BPendingGroup *pg, BThreadWorkDispatcher *twd, void *user,
BLog_logfunc logfunc,
PeerChat_handler_error handler_error,
PeerChat_handler_message handler_message)
{
ASSERT(ssl_mode == PEERCHAT_SSL_NONE || ssl_mode == PEERCHAT_SSL_CLIENT || ssl_mode == PEERCHAT_SSL_SERVER)
ASSERT(ssl_mode == PEERCHAT_SSL_NONE || ssl_peer_cert_len >= 0)
ASSERT(logfunc)
ASSERT(handler_error)
ASSERT(handler_message)
// init arguments
o->ssl_mode = ssl_mode;
o->ssl_cert = ssl_cert;
o->ssl_key = ssl_key;
o->ssl_peer_cert = ssl_peer_cert;
o->ssl_peer_cert_len = ssl_peer_cert_len;
o->user = user;
o->logfunc = logfunc;
o->handler_error = handler_error;
o->handler_message = handler_message;
// init copier
PacketCopier_Init(&o->copier, SC_MAX_MSGLEN, pg);
// init SC encoder
SCOutmsgEncoder_Init(&o->sc_encoder, peer_id, PacketCopier_GetOutput(&o->copier), pg);
// init PacketProto encoder
PacketProtoEncoder_Init(&o->pp_encoder, SCOutmsgEncoder_GetOutput(&o->sc_encoder), pg);
// init recv job
BPending_Init(&o->recv_job, pg, (BPending_handler)recv_job_handler, o);
// set no received data
o->recv_data_len = -1;
PacketPassInterface *send_buf_output = PacketCopier_GetInput(&o->copier);
if (o->ssl_mode != PEERCHAT_SSL_NONE) {
// init receive buffer
if (!SimpleStreamBuffer_Init(&o->ssl_recv_buf, PEERCHAT_SSL_RECV_BUF_SIZE, pg)) {
PeerLog(o, BLOG_ERROR, "SimpleStreamBuffer_Init failed");
goto fail1;
}
// init SSL StreamPacketSender
StreamPacketSender_Init(&o->ssl_sp_sender, send_buf_output, pg);
// init SSL bottom prfd
if (!BSSLConnection_MakeBackend(&o->ssl_bottom_prfd, StreamPacketSender_GetInput(&o->ssl_sp_sender), SimpleStreamBuffer_GetOutput(&o->ssl_recv_buf), twd, ssl_flags)) {
PeerLog(o, BLOG_ERROR, "BSSLConnection_MakeBackend failed");
goto fail2;
}
// init SSL prfd
if (!(o->ssl_prfd = SSL_ImportFD(NULL, &o->ssl_bottom_prfd))) {
ASSERT_FORCE(PR_Close(&o->ssl_bottom_prfd) == PR_SUCCESS)
PeerLog(o, BLOG_ERROR, "SSL_ImportFD failed");
goto fail2;
}
// set client or server mode
if (SSL_ResetHandshake(o->ssl_prfd, (o->ssl_mode == PEERCHAT_SSL_SERVER ? PR_TRUE : PR_FALSE)) != SECSuccess) {
PeerLog(o, BLOG_ERROR, "SSL_ResetHandshake failed");
goto fail3;
}
if (o->ssl_mode == PEERCHAT_SSL_SERVER) {
// set server certificate
if (SSL_ConfigSecureServer(o->ssl_prfd, o->ssl_cert, o->ssl_key, NSS_FindCertKEAType(o->ssl_cert)) != SECSuccess) {
PeerLog(o, BLOG_ERROR, "SSL_ConfigSecureServer failed");
goto fail3;
}
// set require client certificate
if (SSL_OptionSet(o->ssl_prfd, SSL_REQUEST_CERTIFICATE, PR_TRUE) != SECSuccess) {
PeerLog(o, BLOG_ERROR, "SSL_OptionSet(SSL_REQUEST_CERTIFICATE) failed");
goto fail3;
}
if (SSL_OptionSet(o->ssl_prfd, SSL_REQUIRE_CERTIFICATE, PR_TRUE) != SECSuccess) {
PeerLog(o, BLOG_ERROR, "SSL_OptionSet(SSL_REQUIRE_CERTIFICATE) failed");
goto fail3;
}
} else {
// set client certificate callback
if (SSL_GetClientAuthDataHook(o->ssl_prfd, (SSLGetClientAuthData)client_auth_data_callback, o) != SECSuccess) {
PeerLog(o, BLOG_ERROR, "SSL_GetClientAuthDataHook failed");
goto fail3;
}
}
// set verify peer certificate hook
if (SSL_AuthCertificateHook(o->ssl_prfd, (SSLAuthCertificate)auth_certificate_callback, o) != SECSuccess) {
PeerLog(o, BLOG_ERROR, "SSL_AuthCertificateHook failed");
goto fail3;
}
// init SSL connection
BSSLConnection_Init(&o->ssl_con, o->ssl_prfd, 0, pg, o, (BSSLConnection_handler)ssl_con_handler);
// init SSL PacketStreamSender
PacketStreamSender_Init(&o->ssl_ps_sender, BSSLConnection_GetSendIf(&o->ssl_con), sizeof(struct packetproto_header) + SC_MAX_MSGLEN, pg);
// init SSL copier
PacketCopier_Init(&o->ssl_copier, SC_MAX_MSGLEN, pg);
// init SSL encoder
PacketProtoEncoder_Init(&o->ssl_encoder, PacketCopier_GetOutput(&o->ssl_copier), pg);
// init SSL buffer
if (!SinglePacketBuffer_Init(&o->ssl_buffer, PacketProtoEncoder_GetOutput(&o->ssl_encoder), PacketStreamSender_GetInput(&o->ssl_ps_sender), pg)) {
PeerLog(o, BLOG_ERROR, "SinglePacketBuffer_Init failed");
goto fail4;
}
// init receive interface
PacketPassInterface_Init(&o->ssl_recv_if, SC_MAX_MSGLEN, (PacketPassInterface_handler_send)ssl_recv_if_handler_send, o, pg);
// init receive decoder
if (!PacketProtoDecoder_Init(&o->ssl_recv_decoder, BSSLConnection_GetRecvIf(&o->ssl_con), &o->ssl_recv_if, pg, o, (PacketProtoDecoder_handler_error)ssl_recv_decoder_handler_error)) {
PeerLog(o, BLOG_ERROR, "PacketProtoDecoder_Init failed");
goto fail5;
}
send_buf_output = PacketCopier_GetInput(&o->ssl_copier);
}
// init send writer
BufferWriter_Init(&o->send_writer, SC_MAX_MSGLEN, pg);
// init send buffer
if (!PacketBuffer_Init(&o->send_buf, BufferWriter_GetOutput(&o->send_writer), send_buf_output, PEERCHAT_SEND_BUF_SIZE, pg)) {
PeerLog(o, BLOG_ERROR, "PacketBuffer_Init failed");
goto fail6;
}
DebugError_Init(&o->d_err, pg);
DebugObject_Init(&o->d_obj);
return 1;
fail6:
BufferWriter_Free(&o->send_writer);
if (o->ssl_mode != PEERCHAT_SSL_NONE) {
PacketProtoDecoder_Free(&o->ssl_recv_decoder);
fail5:
PacketPassInterface_Free(&o->ssl_recv_if);
SinglePacketBuffer_Free(&o->ssl_buffer);
fail4:
PacketProtoEncoder_Free(&o->ssl_encoder);
PacketCopier_Free(&o->ssl_copier);
PacketStreamSender_Free(&o->ssl_ps_sender);
BSSLConnection_Free(&o->ssl_con);
fail3:
ASSERT_FORCE(PR_Close(o->ssl_prfd) == PR_SUCCESS)
fail2:
StreamPacketSender_Free(&o->ssl_sp_sender);
SimpleStreamBuffer_Free(&o->ssl_recv_buf);
}
fail1:
BPending_Free(&o->recv_job);
PacketProtoEncoder_Free(&o->pp_encoder);
SCOutmsgEncoder_Free(&o->sc_encoder);
PacketCopier_Free(&o->copier);
return 0;
}
void PeerChat_Free (PeerChat *o)
{
DebugObject_Free(&o->d_obj);
DebugError_Free(&o->d_err);
// stop using any buffers before they get freed
if (o->ssl_mode != PEERCHAT_SSL_NONE) {
BSSLConnection_ReleaseBuffers(&o->ssl_con);
}
PacketBuffer_Free(&o->send_buf);
BufferWriter_Free(&o->send_writer);
if (o->ssl_mode != PEERCHAT_SSL_NONE) {
PacketProtoDecoder_Free(&o->ssl_recv_decoder);
PacketPassInterface_Free(&o->ssl_recv_if);
SinglePacketBuffer_Free(&o->ssl_buffer);
PacketProtoEncoder_Free(&o->ssl_encoder);
PacketCopier_Free(&o->ssl_copier);
PacketStreamSender_Free(&o->ssl_ps_sender);
BSSLConnection_Free(&o->ssl_con);
ASSERT_FORCE(PR_Close(o->ssl_prfd) == PR_SUCCESS)
StreamPacketSender_Free(&o->ssl_sp_sender);
SimpleStreamBuffer_Free(&o->ssl_recv_buf);
}
BPending_Free(&o->recv_job);
PacketProtoEncoder_Free(&o->pp_encoder);
SCOutmsgEncoder_Free(&o->sc_encoder);
PacketCopier_Free(&o->copier);
}
PacketRecvInterface * PeerChat_GetSendOutput (PeerChat *o)
{
DebugObject_Access(&o->d_obj);
return PacketProtoEncoder_GetOutput(&o->pp_encoder);
}
void PeerChat_InputReceived (PeerChat *o, uint8_t *data, int data_len)
{
DebugObject_Access(&o->d_obj);
DebugError_AssertNoError(&o->d_err);
ASSERT(o->recv_data_len == -1)
ASSERT(data_len >= 0)
ASSERT(data_len <= SC_MAX_MSGLEN)
// remember data
o->recv_data = data;
o->recv_data_len = data_len;
// set received job
BPending_Set(&o->recv_job);
}
int PeerChat_StartMessage (PeerChat *o, uint8_t **data)
{
DebugObject_Access(&o->d_obj);
DebugError_AssertNoError(&o->d_err);
return BufferWriter_StartPacket(&o->send_writer, data);
}
void PeerChat_EndMessage (PeerChat *o, int data_len)
{
DebugObject_Access(&o->d_obj);
DebugError_AssertNoError(&o->d_err);
ASSERT(data_len >= 0)
ASSERT(data_len <= SC_MAX_MSGLEN)
BufferWriter_EndPacket(&o->send_writer, data_len);
}