added keyboard-interactive client support

--HG--
extra : convert_revision : 3df738e42f4fc8b7f0f3ff9ca767386f54edb1ea

cli-authinteract.c

@@ -0,0 +1,168 @@
+/*
+ * Dropbear SSH
+ * 
+ * Copyright (c) 2005 Matt Johnston
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE. */
+
+#include "includes.h"
+#include "buffer.h"
+#include "dbutil.h"
+#include "session.h"
+#include "ssh.h"
+#include "runopts.h"
+
+#ifdef ENABLE_CLI_INTERACT_AUTH
+
+static unsigned char* get_response(unsigned char* prompt)
+{
+	FILE* tty = NULL;
+	unsigned char* response = NULL;
+	/* not a password, but a reasonable limit */
+	char buf[DROPBEAR_MAX_CLI_PASS];
+	char* ret = NULL;
+
+	fprintf(stderr, "%s", prompt);
+
+	tty = fopen(_PATH_TTY, "r");
+	if (tty) {
+		ret = fgets(buf, sizeof(buf), tty);
+		fclose(tty);
+	} else {
+		ret = fgets(buf, sizeof(buf), stdin);
+	}
+
+	if (ret == NULL) {
+		response = (unsigned char*)m_strdup("");
+	} else {
+		unsigned int buflen = strlen(buf);
+		/* fgets includes newlines */
+		if (buflen > 0 && buf[buflen-1] == '\n')
+			buf[buflen-1] = '\0';
+		response = (unsigned char*)m_strdup(buf);
+	}
+
+	m_burn(buf, sizeof(buf));
+
+	return response;
+}
+
+void recv_msg_userauth_info_request() {
+
+	unsigned char *name = NULL;
+	unsigned char *instruction = NULL;
+	unsigned int num_prompts = 0;
+	unsigned int i;
+
+	unsigned char *prompt = NULL;
+	unsigned int echo = 0;
+	unsigned char *response = NULL;
+
+	TRACE(("enter recv_msg_recv_userauth_info_request"))
+
+	cli_ses.interact_request_received = 1;
+
+	name = buf_getstring(ses.payload, NULL);
+	instruction = buf_getstring(ses.payload, NULL);
+
+	/* language tag */
+	buf_eatstring(ses.payload);
+
+	num_prompts = buf_getint(ses.payload);
+	
+	if (num_prompts >= DROPBEAR_MAX_CLI_INTERACT_PROMPTS) {
+		dropbear_exit("Too many prompts received for keyboard-interactive");
+	}
+
+	/* we'll build the response as we go */
+	CHECKCLEARTOWRITE();
+	buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_INFO_RESPONSE);
+	buf_putint(ses.writepayload, num_prompts);
+
+	if (strlen(name) > 0) {
+		cleantext(name);
+		fprintf(stderr, "%s", name);
+		m_free(name);
+	}
+	if (strlen(instruction) > 0) {
+		cleantext(instruction);
+		fprintf(stderr, "%s", instruction);
+		m_free(instruction);
+	}
+
+	for (i = 0; i < num_prompts; i++) {
+		unsigned int response_len = 0;
+		prompt = buf_getstring(ses.payload, NULL);
+		cleantext(prompt);
+
+		echo = buf_getbool(ses.payload);
+
+		if (echo) {
+			unsigned char* p = getpass(prompt);
+			response = m_strdup(p);
+			m_burn(p, strlen(p));
+		} else {
+			response = get_response(prompt);
+		}
+
+		response_len = strlen(response);
+		buf_putstring(ses.writepayload, response, response_len);
+		m_burn(response, response_len);
+		m_free(response);
+	}
+
+	encrypt_packet();
+
+
+	TRACE(("leave recv_msg_recv_userauth_info_request"))
+}
+
+void cli_auth_interactive() {
+
+	TRACE(("enter cli_auth_interactive"))
+	CHECKCLEARTOWRITE();
+
+	buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_REQUEST);
+
+	/* username */
+	buf_putstring(ses.writepayload, cli_opts.username,
+			strlen(cli_opts.username));
+
+	/* service name */
+	buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION, 
+			SSH_SERVICE_CONNECTION_LEN);
+
+	/* method */
+	buf_putstring(ses.writepayload, AUTH_METHOD_INTERACT,
+			AUTH_METHOD_INTERACT_LEN);
+
+	/* empty language tag */
+	buf_putstring(ses.writepayload, "", 0);
+
+	/* empty submethods */
+	buf_putstring(ses.writepayload, "", 0);
+
+	encrypt_packet();
+	cli_ses.interact_request_received = 0;
+
+	TRACE(("leave cli_auth_interactive"))
+
+}
+#endif	/* ENABLE_CLI_INTERACT_AUTH */