openssh-portable/contrib/win32/win32compat/ssh-agent/connection.c

226 lines
6.9 KiB
C

/*
* Author: Manoj Ampalam <manoj.ampalam@microsoft.com>
* ssh-agent implementation on Windows
*
* Copyright (c) 2015 Microsoft Corp.
* All rights reserved
*
* Microsoft openssh win32 port
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 "agent.h"
#include "agent-request.h"
int process_request(struct agent_connection*);
#define ABORT_CONNECTION_RETURN(c) do { \
c->state = DONE; \
agent_cleanup_connection(c); \
return; \
} while (0)
void
agent_connection_on_error(struct agent_connection* con, DWORD error)
{
ABORT_CONNECTION_RETURN(con);
}
void
agent_connection_on_io(struct agent_connection* con, DWORD bytes, OVERLAPPED* ol)
{
/* process error */
debug3("connection io %p #bytes:%d state:%d", con, bytes, con->state);
if ((bytes == 0) && (GetOverlappedResult(con->pipe_handle, ol, &bytes, FALSE) == FALSE))
ABORT_CONNECTION_RETURN(con);
if (con->state == DONE)
DebugBreak();
switch (con->state) {
case LISTENING:
case WRITING:
/* Writing is done, read next request */
/* assert on assumption that write always completes on sending all bytes*/
if (bytes != con->io_buf.num_bytes)
DebugBreak();
con->state = READING_HEADER;
ZeroMemory(&con->io_buf, sizeof(con->io_buf));
if (!ReadFile(con->pipe_handle, con->io_buf.buf,
HEADER_SIZE, NULL, &con->ol) && (GetLastError() != ERROR_IO_PENDING))
ABORT_CONNECTION_RETURN(con);
break;
case READING_HEADER:
con->io_buf.transferred += bytes;
if (con->io_buf.transferred == HEADER_SIZE) {
con->io_buf.num_bytes = PEEK_U32(con->io_buf.buf);
con->io_buf.transferred = 0;
if (con->io_buf.num_bytes > MAX_MESSAGE_SIZE)
ABORT_CONNECTION_RETURN(con);
con->state = READING;
if (!ReadFile(con->pipe_handle, con->io_buf.buf,
con->io_buf.num_bytes, NULL, &con->ol)&&(GetLastError() != ERROR_IO_PENDING))
ABORT_CONNECTION_RETURN(con);
} else {
if (!ReadFile(con->pipe_handle, con->io_buf.buf + con->io_buf.num_bytes,
HEADER_SIZE - con->io_buf.num_bytes, NULL, &con->ol)&& (GetLastError() != ERROR_IO_PENDING))
ABORT_CONNECTION_RETURN(con);
}
break;
case READING:
con->io_buf.transferred += bytes;
if (con->io_buf.transferred == con->io_buf.num_bytes) {
if (process_request(con) != 0) {
ABORT_CONNECTION_RETURN(con);
}
con->state = WRITING;
if (!WriteFile(con->pipe_handle, con->io_buf.buf,
con->io_buf.num_bytes, NULL, &con->ol)&& (GetLastError() != ERROR_IO_PENDING) )
ABORT_CONNECTION_RETURN(con);
} else {
if (!ReadFile(con->pipe_handle, con->io_buf.buf + con->io_buf.transferred,
con->io_buf.num_bytes - con->io_buf.transferred, NULL, &con->ol)&& (GetLastError() != ERROR_IO_PENDING))
ABORT_CONNECTION_RETURN(con);
}
break;
default:
DebugBreak();
}
}
void
agent_connection_disconnect(struct agent_connection* con)
{
CancelIoEx(con->pipe_handle, NULL);
DisconnectNamedPipe(con->pipe_handle);
}
static int
get_con_client_type(struct agent_connection* con)
{
int r = -1;
char system_sid[SECURITY_MAX_SID_SIZE];
char ns_sid[SECURITY_MAX_SID_SIZE];
char ls_sid[SECURITY_MAX_SID_SIZE];
DWORD reg_dom_len = 0, info_len = 0, sid_size;
SID_NAME_USE nuse;
HANDLE token;
TOKEN_USER* info = NULL;
HANDLE pipe = con->pipe_handle;
if (ImpersonateNamedPipeClient(pipe) == FALSE)
return -1;
if (OpenThreadToken(GetCurrentThread(), TOKEN_QUERY, FALSE, &token) == FALSE ||
GetTokenInformation(token, TokenUser, NULL, 0, &info_len) == TRUE ||
(info = (TOKEN_USER*)malloc(info_len)) == NULL ||
GetTokenInformation(token, TokenUser, info, info_len, &info_len) == FALSE)
goto done;
sid_size = SECURITY_MAX_SID_SIZE;
if (CreateWellKnownSid(WinLocalSystemSid, NULL, system_sid, &sid_size) == FALSE)
goto done;
sid_size = SECURITY_MAX_SID_SIZE;
if (CreateWellKnownSid(WinNetworkServiceSid, NULL, ns_sid, &sid_size) == FALSE)
goto done;
sid_size = SECURITY_MAX_SID_SIZE;
if (CreateWellKnownSid(WinLocalServiceSid, NULL, ls_sid, &sid_size) == FALSE)
goto done;
if (EqualSid(info->User.Sid, system_sid) ||
EqualSid(info->User.Sid, ls_sid) ||
EqualSid(info->User.Sid, ns_sid))
con->client_type = MACHINE;
else
con->client_type = USER;
debug2("client type: %s", con->client_type == MACHINE? "machine" : "user");
r = 0;
done:
if (info)
free(info);
RevertToSelf();
return r;
}
static int
process_request(struct agent_connection* con)
{
int r = -1;
struct sshbuf *request = NULL, *response = NULL;
u_char type;
if (con->client_type == UNKNOWN && get_con_client_type(con) == -1) {
debug("unable to get client process type");
goto done;
}
request = sshbuf_from(con->io_buf.buf, con->io_buf.num_bytes);
response = sshbuf_new();
if ((request == NULL) || (response == NULL))
goto done;
if (sshbuf_get_u8(request, &type) != 0)
return -1;
debug("process agent request type %d", type);
switch (type) {
case SSH2_AGENTC_ADD_IDENTITY:
r = process_add_identity(request, response, con);
break;
case SSH2_AGENTC_REQUEST_IDENTITIES:
r = process_request_identities(request, response, con);
break;
case SSH2_AGENTC_SIGN_REQUEST:
r = process_sign_request(request, response, con);
break;
case SSH2_AGENTC_REMOVE_IDENTITY:
r = process_remove_key(request, response, con);
break;
case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
r = process_remove_all(request, response, con);
break;
case SSH_AGENT_AUTHENTICATE:
r = process_authagent_request(request, response, con);
break;
default:
debug("unknown agent request %d", type);
r = -1;
break;
}
done:
if (request)
sshbuf_free(request);
ZeroMemory(&con->io_buf, sizeof(con->io_buf));
if (r == 0) {
POKE_U32(con->io_buf.buf, sshbuf_len(response));
memcpy(con->io_buf.buf + 4, sshbuf_ptr(response), sshbuf_len(response));
con->io_buf.num_bytes = sshbuf_len(response) + 4;
}
if (response)
sshbuf_free(response);
return r;
}