extcap: move ssh common functions to ssh-base.

Change-Id: Ic06882a4f914b4f89d936d5d942b50552ae4abb3
Reviewed-on: https://code.wireshark.org/review/14264
Petri-Dish: Roland Knall <rknall@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Roland Knall <rknall@gmail.com>

5 files changed, 226 insertions, 129 deletions

diff --git a/extcap/Makefile.common b/extcap/Makefile.common
index 345872f832..22ca1dc7b3 100644
--- a/extcap/Makefile.common
+++ b/extcap/Makefile.common
@@ -34,7 +34,9 @@ randpktdump_SOURCES =	\
 # sshdump specifics
 sshdump_SOURCES =	\
 	sshdump.c	\
-	extcap-base.c
+	extcap-base.c \
+	ssh-base.c
 
 noinst_HEADERS = \
-	extcap-base.h
+	extcap-base.h \
+	ssh-base.h
diff --git a/extcap/Makefile.nmake b/extcap/Makefile.nmake
index 52d35c7c73..6fffad7599 100644
--- a/extcap/Makefile.nmake
+++ b/extcap/Makefile.nmake
@@ -88,10 +88,10 @@ randpktdump.exe	: $(LIBS_CHECK) ..\config.h randpktdump.obj extcap-base.obj $(ra
 !ENDIF
 
 !IFDEF LIBSSH_DIR
-sshdump.exe	: $(LIBS_CHECK) ..\config.h sshdump.obj extcap-base.obj $(sshdump_WSLIBS)
+sshdump.exe	: $(LIBS_CHECK) ..\config.h sshdump.obj extcap-base.obj ssh-base.obj $(sshdump_WSLIBS)
 	@echo Linking $@
 	$(LINK) @<<
-		/OUT:sshdump.exe $(conflags) $(conlibsdll) $(LDFLAGS) /SUBSYSTEM:WINDOWS sshdump.obj extcap-base.obj $(sshdump_LIBS)
+		/OUT:sshdump.exe $(conflags) $(conlibsdll) $(LDFLAGS) /SUBSYSTEM:WINDOWS sshdump.obj extcap-base.obj ssh-base.obj $(sshdump_LIBS)
 <<
 !IFDEF MANIFEST_INFO_REQUIRED
 	mt.exe -nologo -manifest "sshdump.exe.manifest" -outputresource:sshdump.exe;1
diff --git a/extcap/ssh-base.c b/extcap/ssh-base.c
new file mode 100644
index 0000000000..10fefd2577
--- /dev/null
+++ b/extcap/ssh-base.c
@@ -0,0 +1,162 @@
+/* ssh-base.c
+ * ssh-base has base utility functions to connect to hosts via ssh
+ *
+ * Copyright 2016, Dario Lombardo
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "ssh-base.h"
+
+#include <extcap/extcap-base.h>
+#include <log.h>
+
+#define verbose_print(...) { if (verbose) printf(__VA_ARGS__); }
+
+ssh_session create_ssh_connection(const char* hostname, const unsigned int port, const char* username,
+	const char* password, const char* sshkey_path, const char* sshkey_passphrase, char** err_info)
+{
+	ssh_session sshs;
+
+	/* Open session and set options */
+	sshs = ssh_new();
+	if (sshs == NULL) {
+		*err_info = g_strdup_printf("Can't create ssh session");
+		return NULL;
+	}
+
+	if (!hostname) {
+		*err_info = g_strdup_printf("Hostname needed");
+		goto failure;
+	}
+
+	if (ssh_options_set(sshs, SSH_OPTIONS_HOST, hostname)) {
+		*err_info = g_strdup_printf("Can't set the hostname: %s", hostname);
+		goto failure;
+	}
+
+	if (port != 0) {
+		if (ssh_options_set(sshs, SSH_OPTIONS_PORT, &port)) {
+			*err_info = g_strdup_printf("Can't set the port: %d", port);
+			goto failure;
+		}
+	}
+
+	if (!username)
+		username = g_get_user_name();
+
+	if (ssh_options_set(sshs, SSH_OPTIONS_USER, username)) {
+		*err_info = g_strdup_printf("Can't set the username: %s", username);
+		goto failure;
+	}
+
+	g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Opening ssh connection to %s@%s:%u", username, hostname, port);
+
+	/* Connect to server */
+	if (ssh_connect(sshs) != SSH_OK) {
+		*err_info = g_strdup_printf("Error connecting to %s@%s:%u (%s)", username, hostname, port,
+			ssh_get_error(sshs));
+		goto failure;
+	}
+
+#ifdef HAVE_LIBSSH_USERAUTH_AGENT
+	g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, ("Connecting using ssh-agent...");
+	/* Try to authenticate using ssh agent */
+	if (ssh_userauth_agent(sshs, NULL) == SSH_AUTH_SUCCESS) {
+		g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "done");
+		return sshs;
+	}
+	g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, ("failed");
+#endif
+
+	/* If a public key path has been provided, try to authenticate using it */
+	if (sshkey_path) {
+		ssh_key pkey = ssh_key_new();
+		int ret;
+
+		g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Connecting using public key in %s...", sshkey_path);
+		ret = ssh_pki_import_privkey_file(sshkey_path, sshkey_passphrase, NULL, NULL, &pkey);
+
+		if (ret == SSH_OK) {
+			if (ssh_userauth_publickey(sshs, NULL, pkey) == SSH_AUTH_SUCCESS) {
+				g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "done");
+				ssh_key_free(pkey);
+				return sshs;
+			}
+		}
+		ssh_key_free(pkey);
+		g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "failed (%s)", ssh_get_error(sshs));
+	}
+
+	/* Try to authenticate using standard public key */
+	g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Connecting using standard public key...");
+	if (ssh_userauth_publickey_auto(sshs, NULL, NULL) == SSH_AUTH_SUCCESS) {
+		g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "done");
+		return sshs;
+	}
+	g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "failed");
+
+	/* If a password has been provided and all previous attempts failed, try to use it */
+	if (password) {
+		g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Connecting using password...");
+		if (ssh_userauth_password(sshs, username, password) == SSH_AUTH_SUCCESS) {
+			g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "done");
+			return sshs;
+		}
+		g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "failed");
+	}
+
+	*err_info = g_strdup_printf("Can't find a valid authentication. Disconnecting.");
+
+	/* All authentication failed. Disconnect and return */
+	ssh_disconnect(sshs);
+
+failure:
+	ssh_free(sshs);
+	return NULL;
+}
+
+void ssh_cleanup(ssh_session* sshs, ssh_channel* channel)
+{
+	if (*channel) {
+		ssh_channel_send_eof(*channel);
+		ssh_channel_close(*channel);
+		ssh_channel_free(*channel);
+		*channel = NULL;
+	}
+
+	if (*sshs) {
+		ssh_disconnect(*sshs);
+		ssh_free(*sshs);
+		*sshs = NULL;
+	}
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ *
+ * vi: set shiftwidth=8 tabstop=8 noexpandtab:
+ * :indentSize=8:tabSize=8:noTabs=false:
+ */
\ No newline at end of file
diff --git a/extcap/ssh-base.h b/extcap/ssh-base.h
new file mode 100644
index 0000000000..07c3e3305a
--- /dev/null
+++ b/extcap/ssh-base.h
@@ -0,0 +1,50 @@
+/* ssh-base.h
+ * ssh-base has base utility functions to connect to hosts via ssh
+ *
+ * Copyright 2016, Dario Lombardo
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __SSHBASE_H__
+#define __SSHBASE_H__
+
+#include <libssh/libssh.h>
+
+/* Create a ssh connection using all the possible authentication menthods */
+ssh_session create_ssh_connection(const char* hostname, const unsigned int port, const char* username,
+	const char* password, const char* sshkey_path, const char* sshkey_passphrase, char** err_info);
+
+/* Clean the current ssh session and channel. */
+void ssh_cleanup(ssh_session* sshs, ssh_channel* channel);
+
+#endif
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 8
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ *
+ * vi: set shiftwidth=8 tabstop=8 noexpandtab:
+ * :indentSize=8:tabSize=8:noTabs=false:
+ */
\ No newline at end of file
diff --git a/extcap/sshdump.c b/extcap/sshdump.c
index f0055fc40e..814328c1ab 100644
--- a/extcap/sshdump.c
+++ b/extcap/sshdump.c
@@ -26,18 +26,11 @@
 
 #include <extcap/extcap-base.h>
 #include <wsutil/interface.h>
+#include <extcap/ssh-base.h>
 
-#include <glib/gstdio.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <stdarg.h>
 #include <errno.h>
-#include <time.h>
 #include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 #include <fcntl.h>
-#include <libssh/libssh.h>
 
 #ifndef STDERR_FILENO
 #define STDERR_FILENO 2
@@ -97,121 +90,6 @@ static struct option longopts[] = {
 
 static char* interfaces_list_to_filter(GSList* if_list, const unsigned int remote_port);
 
-static void ssh_cleanup(ssh_session sshs, ssh_channel channel)
-{
-	if (channel) {
-		ssh_channel_send_eof(channel);
-		ssh_channel_close(channel);
-		ssh_channel_free(channel);
-	}
-
-	if (sshs) {
-		ssh_disconnect(sshs);
-		ssh_free(sshs);
-	}
-}
-
-static ssh_session create_ssh_connection(const char* hostname, const unsigned int port, const char* username,
-	const char* password, const char* sshkey_path, const char* sshkey_passphrase)
-{
-	ssh_session sshs;
-
-	/* Open session and set options */
-	sshs = ssh_new();
-	if (sshs == NULL) {
-		errmsg_print("Can't create ssh session");
-		return NULL;
-	}
-
-	if (!hostname)
-		return NULL;
-
-	if (ssh_options_set(sshs, SSH_OPTIONS_HOST, hostname)) {
-		errmsg_print("Can't set the hostname: %s", hostname);
-		goto failure;
-	}
-
-	if (port != 0) {
-		if (ssh_options_set(sshs, SSH_OPTIONS_PORT, &port)) {
-			errmsg_print("Can't set the port: %d", port);
-			goto failure;
-		}
-	}
-
-	if (!username)
-		username = g_get_user_name();
-
-	if (ssh_options_set(sshs, SSH_OPTIONS_USER, username)) {
-		errmsg_print("Can't set the username: %s", username);
-		goto failure;
-	}
-
-	verbose_print("Opening ssh connection to %s@%s:%u", username, hostname, port);
-
-	/* Connect to server */
-	if (ssh_connect(sshs) != SSH_OK) {
-		errmsg_print("Error connecting to %s@%s:%u (%s)", username, hostname, port,
-			ssh_get_error(sshs));
-		goto failure;
-	}
-
-#ifdef HAVE_LIBSSH_USERAUTH_AGENT
-	verbose_print("Connecting using ssh-agent...");
-	/* Try to authenticate using ssh agent */
-	if (ssh_userauth_agent(sshs, NULL) == SSH_AUTH_SUCCESS) {
-		verbose_print("done\n");
-		return sshs;
-	}
-	verbose_print("failed\n");
-#endif
-
-	/* If a public key path has been provided, try to authenticate using it */
-	if (sshkey_path) {
-		ssh_key pkey = ssh_key_new();
-		int ret;
-
-		verbose_print("Connecting using public key in %s...", sshkey_path);
-		ret = ssh_pki_import_privkey_file(sshkey_path, sshkey_passphrase, NULL, NULL, &pkey);
-
-		if (ret == SSH_OK) {
-			if (ssh_userauth_publickey(sshs, NULL, pkey) == SSH_AUTH_SUCCESS) {
-				verbose_print("done\n");
-				ssh_key_free(pkey);
-				return sshs;
-			}
-		}
-		ssh_key_free(pkey);
-		verbose_print("failed (%s)\n", ssh_get_error(sshs));
-	}
-
-	/* Try to authenticate using standard public key */
-	verbose_print("Connecting using standard public key...");
-	if (ssh_userauth_publickey_auto(sshs, NULL, NULL) == SSH_AUTH_SUCCESS) {
-		verbose_print("done\n");
-		return sshs;
-	}
-	verbose_print("failed\n");
-
-	/* If a password has been provided and all previous attempts failed, try to use it */
-	if (password) {
-		verbose_print("Connecting using password...");
-		if (ssh_userauth_password(sshs, username, password) == SSH_AUTH_SUCCESS) {
-			verbose_print("done\n");
-			return sshs;
-		}
-		verbose_print("failed\n");
-	}
-
-	errmsg_print("Can't find a valid authentication. Disconnecting.");
-
-	/* All authentication failed. Disconnect and return */
-	ssh_disconnect(sshs);
-
-failure:
-	ssh_free(sshs);
-	return NULL;
-}
-
 static void ssh_loop_read(ssh_channel channel, int fd)
 {
 	int nbytes;
@@ -314,6 +192,7 @@ static int ssh_open_remote_connection(const char* hostname, const unsigned int p
 	ssh_channel channel = NULL;
 	int fd = STDOUT_FILENO;
 	int ret = EXIT_FAILURE;
+	char* err_info = NULL;
 
 	if (g_strcmp0(fifo, "-")) {
 		/* Open or create the output file */
@@ -327,7 +206,7 @@ static int ssh_open_remote_connection(const char* hostname, const unsigned int p
 		}
 	}
 
-	sshs = create_ssh_connection(hostname, port, username, password, sshkey, sshkey_passphrase);
+	sshs = create_ssh_connection(hostname, port, username, password, sshkey, sshkey_passphrase, &err_info);
 
 	if (!sshs)
 		goto cleanup;
@@ -341,8 +220,12 @@ static int ssh_open_remote_connection(const char* hostname, const unsigned int p
 
 	ret = EXIT_SUCCESS;
 cleanup:
+	if (err_info)
+		errmsg_print("%s", err_info);
+	g_free(err_info);
+
 	/* clean up and exit */
-	ssh_cleanup(sshs, channel);
+	ssh_cleanup(&sshs, &channel);
 
 	if (g_strcmp0(fifo, "-"))
 		close(fd);