diff --git a/contrib/win32/win32compat/ssh-agent/agent.c b/contrib/win32/win32compat/ssh-agent/agent.c
index 3354e55..7322ca2 100644
--- a/contrib/win32/win32compat/ssh-agent/agent.c
+++ b/contrib/win32/win32compat/ssh-agent/agent.c
@@ -65,7 +65,7 @@ init_listeners() {
 		listeners[i].pipe_id = pipe_ids[i];
 		listeners[i].type = pipe_types[i];
 		listeners[i].pipe = INVALID_HANDLE_VALUE;
-		listeners[i].sa.bInheritHandle = TRUE;
+		listeners[i].sa.bInheritHandle = FALSE;
 		if (!ConvertStringSecurityDescriptorToSecurityDescriptorW(pipe_sddls[i], SDDL_REVISION_1,
 			&listeners[i].sa.lpSecurityDescriptor, &listeners[i].sa.nLength)) {
 			debug("cannot convert sddl ERROR:%d", GetLastError());
@@ -111,7 +111,6 @@ iocp_work(LPVOID lpParam) {
 	}
 }
 
-
 static void
 process_connection(HANDLE pipe, int type) {
 	struct agent_connection* con;
@@ -124,7 +123,7 @@ process_connection(HANDLE pipe, int type) {
 	con->type = type;
 	if (CreateIoCompletionPort(pipe, ioc_port, (ULONG_PTR)con, 0) != ioc_port)
 		fatal("failed to assign pipe to ioc_port");
-	
+
 	agent_connection_on_io(con, 0, &con->ol);
 	return iocp_work(NULL);
 }
@@ -185,8 +184,10 @@ agent_listen_loop() {
 		else if ((r > WAIT_OBJECT_0) && (r <= (WAIT_OBJECT_0 + NUM_LISTENERS))) {
 			/* process incoming connection */
 			HANDLE con = listeners[r - 1].pipe;
+			DWORD client_pid = 0;
 			listeners[r - 1].pipe = INVALID_HANDLE_VALUE;
-			verbose("client connected on %ls", pipe_ids[r-1]);
+			GetNamedPipeClientProcessId(con, &client_pid);
+			verbose("client pid %d connected on %ls", client_pid, pipe_ids[r-1]);
 			if (debug_mode) {
 				process_connection(con, listeners[r - 1].type);
 				agent_cleanup();
@@ -201,6 +202,7 @@ agent_listen_loop() {
 				si.cb = sizeof(STARTUPINFOW);
 				memset(&si, 0, sizeof(STARTUPINFOW));
 				GetModuleFileNameW(NULL, module_path, MAX_PATH);
+				SetHandleInformation(con, HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT);
 				if ((swprintf_s(path, MAX_PATH, L"%s %d %d", module_path, con, listeners[r - 1].type) == -1 ) ||
 				    (CreateProcessW(NULL, path, NULL, NULL, TRUE,
 					DETACHED_PROCESS, NULL, NULL,
@@ -212,6 +214,7 @@ agent_listen_loop() {
 					CloseHandle(pi.hProcess);
 					CloseHandle(pi.hThread);
 				}
+				SetHandleInformation(con, HANDLE_FLAG_INHERIT, 0);
 				CloseHandle(con);				
 			}
 			
diff --git a/contrib/win32/win32compat/ssh-agent/agent.h b/contrib/win32/win32compat/ssh-agent/agent.h
index afc0a44..639c37f 100644
--- a/contrib/win32/win32compat/ssh-agent/agent.h
+++ b/contrib/win32/win32compat/ssh-agent/agent.h
@@ -31,6 +31,13 @@ struct agent_connection {
 		WRITING,
 		DONE
 	} state;
+	enum {
+		UNKNOWN = 0,
+		OTHER,
+		LOCAL_SYSTEM,
+		SSHD,
+		NETWORK_SERVICE
+	} client_type;
 	enum agent_type type;
 };
 
diff --git a/contrib/win32/win32compat/ssh-agent/connection.c b/contrib/win32/win32compat/ssh-agent/connection.c
index 4192e22..2a19282 100644
--- a/contrib/win32/win32compat/ssh-agent/connection.c
+++ b/contrib/win32/win32compat/ssh-agent/connection.c
@@ -114,17 +114,74 @@ void agent_connection_disconnect(struct agent_connection* con) {
 	DisconnectNamedPipe(con->connection);
 }
 
+static int
+get_con_client_type(HANDLE pipe) {
+	int r = -1;
+	wchar_t *sshd_act = L"NT SERVICE\\SSHD", *ref_dom = NULL;
+	PSID sshd_sid = NULL;
+	char system_sid[SECURITY_MAX_SID_SIZE];
+	char ns_sid[SECURITY_MAX_SID_SIZE];
+	DWORD sshd_sid_len = 0, reg_dom_len = 0, info_len = 0, sid_size;
+	SID_NAME_USE nuse;
+	HANDLE token;
+	TOKEN_USER* info = NULL;
+
+	if (ImpersonateNamedPipeClient(pipe) == FALSE)
+		return -1;
+
+	if (LookupAccountNameW(NULL, sshd_act, NULL, &sshd_sid_len, NULL, &reg_dom_len, &nuse) == TRUE ||
+		(sshd_sid = malloc(sshd_sid_len)) == NULL ||
+		(ref_dom = (wchar_t*)malloc(reg_dom_len * 2)) == NULL ||
+		LookupAccountNameW(NULL, sshd_act, sshd_sid, &sshd_sid_len, ref_dom, &reg_dom_len, &nuse) == FALSE ||
+		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;
+
+	if (EqualSid(info->User.Sid, system_sid))
+		r = LOCAL_SYSTEM;
+	else if (EqualSid(info->User.Sid, sshd_sid))
+		r = SSHD;
+	else if (EqualSid(info->User.Sid, ns_sid))
+		r = NETWORK_SERVICE;
+	else
+		r = OTHER;
+
+	debug("client type: %d", r);
+done:
+	if (sshd_sid)
+		free(sshd_sid);
+	if (ref_dom)
+		free(ref_dom);
+	if (info)
+		free(info);
+	RevertToSelf();
+	return r;
+}
+
+
 static int
 process_request(struct agent_connection* con) {
-	int r;
+	int r = -1;
 	struct sshbuf *request = NULL, *response = NULL;
+
+	if (con->client_type == UNKNOWN)
+		if ((con->client_type = get_con_client_type(con->connection)) == -1)
+			goto done;
+
 	
 	request = sshbuf_from(con->io_buf.buf, con->io_buf.num_bytes);
 	response = sshbuf_new();
-	if ((request == NULL) || (response == NULL)) {
-		r = ENOMEM;
+	if ((request == NULL) || (response == NULL))
 		goto done;
-	}
 
 	if (con->type == KEY_AGENT)
 		r = process_keyagent_request(request, response, con);
@@ -132,8 +189,6 @@ process_request(struct agent_connection* con) {
 		r = process_pubkeyagent_request(request, response, con);
 	else if (con->type == PUBKEY_AUTH_AGENT) 
 		r = process_authagent_request(request, response, con);
-	else 
-		r = EINVAL;
 
 done:
 	if (request)
diff --git a/contrib/win32/win32compat/ssh-agent/keyagent-request.c b/contrib/win32/win32compat/ssh-agent/keyagent-request.c
index b52bedf..287a56a 100644
--- a/contrib/win32/win32compat/ssh-agent/keyagent-request.c
+++ b/contrib/win32/win32compat/ssh-agent/keyagent-request.c
@@ -40,9 +40,12 @@ static int
 get_user_root(struct agent_connection* con, HKEY *root){
 	int r = 0;
 	if (ImpersonateNamedPipeClient(con->connection) == FALSE)
-		return ERROR_INTERNAL_ERROR;
+		return -1;
 	
-	r = RegOpenCurrentUser(KEY_ALL_ACCESS, root);
+	if (con->client_type > OTHER)
+		*root = HKEY_LOCAL_MACHINE;
+	else if (RegOpenCurrentUser(KEY_ALL_ACCESS, root) != ERROR_SUCCESS)
+		r = -1;
 
 	RevertToSelf();
 	return r;
@@ -52,8 +55,10 @@ static int
 convert_blob(struct agent_connection* con, const char *blob, DWORD blen, char **eblob, DWORD *eblen, int encrypt) {
 	int success = 0;
 	DATA_BLOB in, out;
-	if (ImpersonateNamedPipeClient(con->connection) == FALSE)
-		return -1;
+
+	if (con->client_type == OTHER)
+		if (ImpersonateNamedPipeClient(con->connection) == FALSE)
+			return -1;
 
 	in.cbData = blen;
 	in.pbData = (char*)blob;
@@ -61,12 +66,16 @@ convert_blob(struct agent_connection* con, const char *blob, DWORD blen, char **
 	out.pbData = NULL;
 
 	if (encrypt) {
-		if (!CryptProtectData(&in, NULL, NULL, 0, NULL, 0, &out))
+		if (!CryptProtectData(&in, NULL, NULL, 0, NULL, 0, &out)) {
+			debug("cannot encrypt data");
 			goto done;
+		}
 	}
 	else {
-		if (!CryptUnprotectData(&in, NULL, NULL, 0, NULL, 0, &out)) 
+		if (!CryptUnprotectData(&in, NULL, NULL, 0, NULL, 0, &out)) {
+			debug("cannot decrypt data");
 			goto done;
+		}
 	}
 
 	*eblob = malloc(out.cbData);
@@ -79,7 +88,8 @@ convert_blob(struct agent_connection* con, const char *blob, DWORD blen, char **
 done:
 	if (out.pbData)
 		LocalFree(out.pbData);
-	RevertToSelf();
+	if (con->client_type == OTHER)
+		RevertToSelf();
 	return success? 0: -1;
 }
 
@@ -182,9 +192,11 @@ static int sign_blob(const struct sshkey *pubkey, u_char ** sig, size_t *siglen,
 	    (tmpbuf = sshbuf_from(keyblob, keyblob_len)) == NULL)
 		goto done;
 
-	if ( sshkey_private_deserialize(tmpbuf, &prikey) != 0 ||
-	     sshkey_sign(prikey, sig, siglen, blob, blen, 0) != 0)
+	if (sshkey_private_deserialize(tmpbuf, &prikey) != 0 ||
+	    sshkey_sign(prikey, sig, siglen, blob, blen, 0) != 0) {
+		debug("cannot sign using retrieved key");
 		goto done;
+	}
 
 	success = 1;
 
@@ -221,6 +233,7 @@ process_sign_request(struct sshbuf* request, struct sshbuf* response, struct age
 	    sshbuf_get_string_direct(request, &data, &dlen) != 0 ||
 	    sshbuf_get_u32(request, &flags) != 0 ||
 	    sshkey_from_blob(blob, blen, &key) != 0) {
+		debug("sign request is invalid");
 		request_invalid = 1;
 		goto done;
 	}
@@ -403,6 +416,8 @@ int process_keyagent_request(struct sshbuf* request, struct sshbuf* response, st
 
 	if ((r = sshbuf_get_u8(request, &type)) != 0)
 		return r;
+	debug2("process key agent request type %d", type);
+
 	switch (type) {
 	case SSH2_AGENTC_ADD_IDENTITY:
 		return process_add_identity(request, response, con);