upstream: let ssh_config(5)'s AddKeysToAgent keyword accept a time

limit for keys in addition to its current flag options. Time-limited keys
will automatically be removed from ssh-agent after their expiry time has
passed; ok markus@

OpenBSD-Commit-ID: 792e71cacbbc25faab5424cf80bee4a006119f94

diff --git a/readconf.c b/readconf.c
index a810736a4b7e9f878fec5c2bc3904420e4274502..94b67e1c6903316371612f17eaa4e73c808bd0d1 100644 (file)
--- a/readconf.c
+++ b/readconf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.c,v 1.333 2020/07/17 07:09:24 dtucker Exp $ */
+/* $OpenBSD: readconf.c,v 1.334 2020/08/11 09:49:57 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -877,6 +877,21 @@ static const struct multistate multistate_compression[] = {
        { NULL, -1 }
 };
 
+static int
+parse_multistate_value(const char *arg, const char *filename, int linenum,
+    const struct multistate *multistate_ptr)
+{
+       int i;
+
+       if (!arg || *arg == '\0')
+               fatal("%s line %d: missing argument.", filename, linenum);
+       for (i = 0; multistate_ptr[i].key != NULL; i++) {
+               if (strcasecmp(arg, multistate_ptr[i].key) == 0)
+                       return multistate_ptr[i].value;
+       }
+       return -1;
+}
+
 /*
  * Processes a single option line as used in the configuration files. This
  * only sets those values that have not already been set.
@@ -1000,19 +1015,11 @@ parse_time:
                multistate_ptr = multistate_flag;
  parse_multistate:
                arg = strdelim(&s);
-               if (!arg || *arg == '\0')
-                       fatal("%s line %d: missing argument.",
-                           filename, linenum);
-               value = -1;
-               for (i = 0; multistate_ptr[i].key != NULL; i++) {
-                       if (strcasecmp(arg, multistate_ptr[i].key) == 0) {
-                               value = multistate_ptr[i].value;
-                               break;
-                       }
-               }
-               if (value == -1)
+               if ((value = parse_multistate_value(arg, filename, linenum,
+                    multistate_ptr)) == -1) {
                        fatal("%s line %d: unsupported option \"%s\".",
                            filename, linenum, arg);
+               }
                if (*activep && *intptr == -1)
                        *intptr = value;
                break;
@@ -1800,9 +1807,42 @@ parse_keytypes:
                goto parse_keytypes;
 
        case oAddKeysToAgent:
-               intptr = &options->add_keys_to_agent;
-               multistate_ptr = multistate_yesnoaskconfirm;
-               goto parse_multistate;
+               arg = strdelim(&s);
+               arg2 = strdelim(&s);
+               value = parse_multistate_value(arg, filename, linenum,
+                    multistate_yesnoaskconfirm);
+               value2 = 0; /* unlimited lifespan by default */
+               if (value == 3 && arg2 != NULL) {
+                       /* allow "AddKeysToAgent confirm 5m" */
+                       if ((value2 = convtime(arg2)) == -1 || value2 > INT_MAX)
+                               fatal("%s line %d: invalid time value.",
+                                   filename, linenum);
+               } else if (value == -1 && arg2 == NULL) {
+                       if ((value2 = convtime(arg)) == -1 || value2 > INT_MAX)
+                               fatal("%s line %d: unsupported option",
+                                   filename, linenum);
+                       value = 1; /* yes */
+               } else if (value == -1 || arg2 != NULL) {
+                       fatal("%s line %d: unsupported option",
+                           filename, linenum);
+               }
+               if (*activep && options->add_keys_to_agent == -1) {
+                       options->add_keys_to_agent = value;
+                       options->add_keys_to_agent_lifespan = value2;
+               }
+               break;
+
+               arg = strdelim(&s);
+               if (!arg || *arg == '\0')
+                       fatal("%s line %d: missing time value.",
+                           filename, linenum);
+               if (strcmp(arg, "none") == 0)
+                       value = -1;
+               else if ((value = convtime(arg)) == -1 || value > INT_MAX)
+                       fatal("%s line %d: invalid time value.",
+                           filename, linenum);
+               if (*activep && *intptr == -1)
+                       *intptr = value;
 
        case oIdentityAgent:
                charptr = &options->identity_agent;
@@ -2016,6 +2056,7 @@ initialize_options(Options * options)
        options->permit_local_command = -1;
        options->remote_command = NULL;
        options->add_keys_to_agent = -1;
+       options->add_keys_to_agent_lifespan = -1;
        options->identity_agent = NULL;
        options->visual_host_key = -1;
        options->ip_qos_interactive = -1;
@@ -2123,8 +2164,10 @@ fill_default_options(Options * options)
        if (options->number_of_password_prompts == -1)
                options->number_of_password_prompts = 3;
        /* options->hostkeyalgorithms, default set in myproposals.h */
-       if (options->add_keys_to_agent == -1)
+       if (options->add_keys_to_agent == -1) {
                options->add_keys_to_agent = 0;
+               options->add_keys_to_agent_lifespan = 0;
+       }
        if (options->num_identity_files == 0) {
                add_identity_file(options, "~/", _PATH_SSH_CLIENT_ID_RSA, 0);
                add_identity_file(options, "~/", _PATH_SSH_CLIENT_ID_DSA, 0);
@@ -2728,7 +2771,6 @@ dump_client_config(Options *o, const char *host)
        dump_cfg_int(oPort, o->port);
 
        /* Flag options */
-       dump_cfg_fmtint(oAddKeysToAgent, o->add_keys_to_agent);
        dump_cfg_fmtint(oAddressFamily, o->address_family);
        dump_cfg_fmtint(oBatchMode, o->batch_mode);
        dump_cfg_fmtint(oCanonicalizeFallbackLocal, o->canonicalize_fallback_local);
@@ -2816,6 +2858,15 @@ dump_client_config(Options *o, const char *host)
 
        /* Special cases */
 
+       /* AddKeysToAgent */
+       if (o->add_keys_to_agent_lifespan <= 0)
+               dump_cfg_fmtint(oAddKeysToAgent, o->add_keys_to_agent);
+       else {
+               printf("addkeystoagent%s %d\n",
+                   o->add_keys_to_agent == 3 ? " confirm" : "",
+                   o->add_keys_to_agent_lifespan);
+       }
+
        /* oForwardAgent */
        if (o->forward_agent_sock_path == NULL)
                dump_cfg_fmtint(oForwardAgent, o->forward_agent);

diff --git a/readconf.h b/readconf.h
index e143a1082aecba1578674b6d9743420abc189314..d6a15550d8f30b7ea27708338e91e0e108ade6ce 100644 (file)
--- a/readconf.h
+++ b/readconf.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.h,v 1.133 2020/04/03 02:27:12 dtucker Exp $ */
+/* $OpenBSD: readconf.h,v 1.134 2020/08/11 09:49:57 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -97,6 +97,7 @@ typedef struct {
        struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES];
 
        int     add_keys_to_agent;
+       int     add_keys_to_agent_lifespan;
        char   *identity_agent;         /* Optional path to ssh-agent socket */
 
        /* Local TCP/IP forward requests. */

diff --git a/ssh_config.5 b/ssh_config.5
index 2b635410f6df0cbb5e745ee918977700dc8068e6..6be1f1aa2176bc8b98d8de2a1ca4677331559f12 100644 (file)
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -33,8 +33,8 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ssh_config.5,v 1.331 2020/07/17 05:59:05 jmc Exp $
-.Dd $Mdocdate: July 17 2020 $
+.\" $OpenBSD: ssh_config.5,v 1.332 2020/08/11 09:49:57 djm Exp $
+.Dd $Mdocdate: August 11 2020 $
 .Dt SSH_CONFIG 5
 .Os
 .Sh NAME
@@ -245,13 +245,22 @@ option was specified to
 If this option is set to
 .Cm no ,
 no keys are added to the agent.
+Alternately, this option may be specified as a time interval
+using the format described in the
+.Sx TIME FORMATS
+section of
+.Xr sshd_config 5
+to specify the key's lifetime in
+.Xr ssh-agent 1 ,
+after which it will automatically be removed.
 The argument must be
-.Cm yes ,
-.Cm confirm ,
-.Cm ask ,
-or
 .Cm no
-(the default).
+(the default),
+.Cm yes ,
+.Cm confirm
+(optionally followed by a time interval),
+.Cm ask
+or a time interval.
 .It Cm AddressFamily
 Specifies which address family to use when connecting.
 Valid arguments are

diff --git a/sshconnect.c b/sshconnect.c
index f6d8a1bcfe21b8eccf8405b7a266314611d30edf..63a97d03989c007a84261a552338b25acf1ec13b 100644 (file)
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.330 2020/07/17 03:43:42 dtucker Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.331 2020/08/11 09:49:57 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1433,7 +1433,8 @@ maybe_add_key_to_agent(const char *authfile, struct sshkey *private,
        if (sshkey_is_sk(private))
                skprovider = options.sk_provider;
        if ((r = ssh_add_identity_constrained(auth_sock, private,
-           comment == NULL ? authfile : comment, 0,
+           comment == NULL ? authfile : comment,
+           options.add_keys_to_agent_lifespan,
            (options.add_keys_to_agent == 3), 0, skprovider)) == 0)
                debug("identity added to agent: %s", authfile);
        else