Mercurial > dropbear
changeset 1442:517c67cbcd31
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 <[email protected]>
| author | Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk> |
|---|---|
| date | Mon, 29 May 2017 10:25:09 +0100 |
| parents | 4f8eb331174f |
| children | 8d45904926d3 |
| files | default_options.h default_options.h.in dropbear.8 runopts.h svr-auth.c svr-runopts.c |
| diffstat | 6 files changed, 32 insertions(+), 1 deletions(-) [+] |
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--- a/default_options.h Sat Jun 24 23:32:25 2017 +0800 +++ b/default_options.h Mon May 29 10:25:09 2017 +0100 @@ -385,6 +385,12 @@ #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
--- a/default_options.h.in Sat Jun 24 23:32:25 2017 +0800 +++ b/default_options.h.in Mon May 29 10:25:09 2017 +0100 @@ -261,6 +261,10 @@ /* Maximum number of failed authentication tries (server option) */ #define MAX_AUTH_TRIES 10 +/* Default maximum number of failed authentication tries. + * defaults to MAX_AUTH_TRIES */ +#define DEFAULT_AUTH_TRIES MAX_AUTH_TRIES + /* The default file to store the daemon's process ID, for shutdown scripts etc. This can be overridden with the -P flag */ #define DROPBEAR_PIDFILE "/var/run/dropbear.pid"
--- a/dropbear.8 Sat Jun 24 23:32:25 2017 +0800 +++ b/dropbear.8 Mon May 29 10:25:09 2017 +0100 @@ -91,6 +91,9 @@ .B \-I \fIidle_timeout Disconnect the session if no traffic is transmitted or received for \fIidle_timeout\fR seconds. .TP +.B \-T \fImax_authentication_attempts +Disconnect the session if number of authentication attempts is exceeded. default is set at compile time to DEFAULT_AUTH_TRIES which itself defaults to MAX_AUTH_TRIES (10) +.TP .B \-c \fIforced_command Disregard the command provided by the user and always run \fIforced_command\fR. This also overrides any authorized_keys command= option.
--- a/runopts.h Sat Jun 24 23:32:25 2017 +0800 +++ b/runopts.h Mon May 29 10:25:09 2017 +0100 @@ -96,6 +96,7 @@ int noauthpass; int norootpass; int allowblankpass; + unsigned int maxauthtries; #if DROPBEAR_SVR_REMOTETCPFWD int noremotetcp;
--- a/svr-auth.c Sat Jun 24 23:32:25 2017 +0800 +++ b/svr-auth.c Mon May 29 10:25:09 2017 +0100 @@ -362,7 +362,7 @@ 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"))
--- a/svr-runopts.c Sat Jun 24 23:32:25 2017 +0800 +++ b/svr-runopts.c Mon May 29 10:25:09 2017 +0100 @@ -73,6 +73,7 @@ "-g Disable password logins for root\n" "-B Allow blank password logins\n" #endif + "-T <1 to %d> Maximum authentication tries (default %d)\n" #if DROPBEAR_SVR_LOCALTCPFWD "-j Disable local port forwarding\n" #endif @@ -107,6 +108,7 @@ #if 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); } @@ -119,6 +121,7 @@ char* recv_window_arg = NULL; char* keepalive_arg = NULL; char* idle_timeout_arg = NULL; + char* maxauthtries_arg = NULL; char* keyfile = NULL; char c; @@ -132,6 +135,7 @@ 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; @@ -235,6 +239,9 @@ case 'I': next = &idle_timeout_arg; break; + case 'T': + next = &maxauthtries_arg; + break; #if DROPBEAR_SVR_PASSWORD_AUTH || DROPBEAR_SVR_PAM_AUTH case 's': svr_opts.noauthpass = 1; @@ -331,6 +338,16 @@ 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;