From 9aaf3d3501642640c9ec74268e671171c8de6103 Mon Sep 17 00:00:00 2001 From: Kevin Darbyshire-Bryant Date: Sun, 25 Jun 2017 21:40:43 +0100 Subject: [PATCH] dropbear: server support option '-T' max auth tries Add support for '-T n' for a run-time specification for maximum number of authentication attempts where 'n' is between 1 and compile time option MAX_AUTH_TRIES. A default number of tries can be specified at compile time using 'DEFAULT_AUTH_TRIES' which itself defaults to MAX_AUTH_TRIES for backwards compatibility. Signed-off-by: Kevin Darbyshire-Bryant --- .../patches/010-runtime-maxauthtries.patch | 130 ++++++++++++++++++ ...610-skip-default-keys-in-custom-runs.patch | 4 +- 2 files changed, 132 insertions(+), 2 deletions(-) create mode 100644 package/network/services/dropbear/patches/010-runtime-maxauthtries.patch diff --git a/package/network/services/dropbear/patches/010-runtime-maxauthtries.patch b/package/network/services/dropbear/patches/010-runtime-maxauthtries.patch new file mode 100644 index 0000000000..26db3181f2 --- /dev/null +++ b/package/network/services/dropbear/patches/010-runtime-maxauthtries.patch @@ -0,0 +1,130 @@ +From 46b22e57d91e33a591d0fba97da52672af4d6ed2 Mon Sep 17 00:00:00 2001 +From: Kevin Darbyshire-Bryant +Date: Mon, 29 May 2017 10:25:09 +0100 +Subject: [PATCH] dropbear server: support -T max auth tries + +Add support for '-T n' for a run-time specification for maximum number +of authentication attempts where 'n' is between 1 and compile time +option MAX_AUTH_TRIES. + +A default number of tries can be specified at compile time using +'DEFAULT_AUTH_TRIES' which itself defaults to MAX_AUTH_TRIES for +backwards compatibility. + +Signed-off-by: Kevin Darbyshire-Bryant +--- + options.h | 7 +++++++ + runopts.h | 1 + + svr-auth.c | 2 +- + svr-runopts.c | 17 +++++++++++++++++ + 4 files changed, 26 insertions(+), 1 deletion(-) + +diff --git a/options.h b/options.h +index 0c51bb1..4d22704 100644 +--- a/options.h ++++ b/options.h +@@ -284,6 +284,13 @@ Homedir is prepended unless path begins with / */ + #define MAX_AUTH_TRIES 10 + #endif + ++/* Default maximum number of failed authentication tries. ++ * defaults to MAX_AUTH_TRIES */ ++ ++#ifndef DEFAULT_AUTH_TRIES ++#define DEFAULT_AUTH_TRIES MAX_AUTH_TRIES ++#endif ++ + /* The default file to store the daemon's process ID, for shutdown + scripts etc. This can be overridden with the -P flag */ + #ifndef DROPBEAR_PIDFILE +diff --git a/runopts.h b/runopts.h +index f7c869d..2f7da63 100644 +--- a/runopts.h ++++ b/runopts.h +@@ -96,6 +96,7 @@ typedef struct svr_runopts { + int noauthpass; + int norootpass; + int allowblankpass; ++ unsigned int maxauthtries; + + #ifdef ENABLE_SVR_REMOTETCPFWD + int noremotetcp; +diff --git a/svr-auth.c b/svr-auth.c +index 577ea88..6a7ce0b 100644 +--- a/svr-auth.c ++++ b/svr-auth.c +@@ -362,7 +362,7 @@ void send_msg_userauth_failure(int partial, int incrfail) { + ses.authstate.failcount++; + } + +- if (ses.authstate.failcount >= MAX_AUTH_TRIES) { ++ if (ses.authstate.failcount >= svr_opts.maxauthtries) { + char * userstr; + /* XXX - send disconnect ? */ + TRACE(("Max auth tries reached, exiting")) +diff --git a/svr-runopts.c b/svr-runopts.c +index 8f60059..1e7440f 100644 +--- a/svr-runopts.c ++++ b/svr-runopts.c +@@ -73,6 +73,7 @@ static void printhelp(const char * progname) { + "-g Disable password logins for root\n" + "-B Allow blank password logins\n" + #endif ++ "-T <1 to %d> Maximum authentication tries (default %d)\n" + #ifdef ENABLE_SVR_LOCALTCPFWD + "-j Disable local port forwarding\n" + #endif +@@ -106,6 +107,7 @@ static void printhelp(const char * progname) { + #ifdef DROPBEAR_ECDSA + ECDSA_PRIV_FILENAME, + #endif ++ MAX_AUTH_TRIES, DEFAULT_AUTH_TRIES, + DROPBEAR_MAX_PORTS, DROPBEAR_DEFPORT, DROPBEAR_PIDFILE, + DEFAULT_RECV_WINDOW, DEFAULT_KEEPALIVE, DEFAULT_IDLE_TIMEOUT); + } +@@ -118,6 +120,7 @@ void svr_getopts(int argc, char ** argv) { + char* recv_window_arg = NULL; + char* keepalive_arg = NULL; + char* idle_timeout_arg = NULL; ++ char* maxauthtries_arg = NULL; + char* keyfile = NULL; + char c; + +@@ -130,6 +133,7 @@ void svr_getopts(int argc, char ** argv) { + svr_opts.noauthpass = 0; + svr_opts.norootpass = 0; + svr_opts.allowblankpass = 0; ++ svr_opts.maxauthtries = DEFAULT_AUTH_TRIES; + svr_opts.inetdmode = 0; + svr_opts.portcount = 0; + svr_opts.hostkey = NULL; +@@ -234,6 +238,9 @@ void svr_getopts(int argc, char ** argv) { + case 'I': + next = &idle_timeout_arg; + break; ++ case 'T': ++ next = &maxauthtries_arg; ++ break; + #if defined(ENABLE_SVR_PASSWORD_AUTH) || defined(ENABLE_SVR_PAM_AUTH) + case 's': + svr_opts.noauthpass = 1; +@@ -330,6 +337,16 @@ void svr_getopts(int argc, char ** argv) { + dropbear_exit("Bad recv window '%s'", recv_window_arg); + } + } ++ ++ if (maxauthtries_arg) { ++ unsigned int val = 0; ++ if (m_str_to_uint(maxauthtries_arg, &val) == DROPBEAR_FAILURE || ++ val == 0 || val > MAX_AUTH_TRIES) { ++ dropbear_exit("Bad maxauthtries '%s'", maxauthtries_arg); ++ } ++ svr_opts.maxauthtries = val; ++ } ++ + + if (keepalive_arg) { + unsigned int val; +-- +2.7.4 + diff --git a/package/network/services/dropbear/patches/610-skip-default-keys-in-custom-runs.patch b/package/network/services/dropbear/patches/610-skip-default-keys-in-custom-runs.patch index f6453a4626..a555a9e498 100644 --- a/package/network/services/dropbear/patches/610-skip-default-keys-in-custom-runs.patch +++ b/package/network/services/dropbear/patches/610-skip-default-keys-in-custom-runs.patch @@ -1,6 +1,6 @@ --- a/svr-runopts.c +++ b/svr-runopts.c -@@ -488,6 +488,7 @@ void load_all_hostkeys() { +@@ -505,6 +505,7 @@ void load_all_hostkeys() { m_free(hostkey_file); } @@ -8,7 +8,7 @@ #ifdef DROPBEAR_RSA loadhostkey(RSA_PRIV_FILENAME, 0); #endif -@@ -499,6 +500,7 @@ void load_all_hostkeys() { +@@ -516,6 +517,7 @@ void load_all_hostkeys() { #ifdef DROPBEAR_ECDSA loadhostkey(ECDSA_PRIV_FILENAME, 0); #endif