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-rw-r--r--auth-options.c1230
1 files changed, 742 insertions, 488 deletions
diff --git a/auth-options.c b/auth-options.c
index 4f0da9c0..696ba6ac 100644
--- a/auth-options.c
+++ b/auth-options.c
@@ -1,441 +1,82 @@
-/* $OpenBSD: auth-options.c,v 1.65 2015/01/14 10:30:34 markus Exp $ */
+/* $OpenBSD: auth-options.c,v 1.92 2020/03/06 18:15:38 markus Exp $ */
/*
- * Author: Tatu Ylonen <ylo@cs.hut.fi>
- * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
- * All rights reserved
- * As far as I am concerned, the code I have written for this software
- * can be used freely for any purpose. Any derived versions of this
- * software must be clearly marked as such, and if the derived work is
- * incompatible with the protocol description in the RFC file, it must be
- * called by a name other than "ssh" or "Secure Shell".
+ * Copyright (c) 2018 Damien Miller <djm@mindrot.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "includes.h"
#include <sys/types.h>
+#include <stdlib.h>
#include <netdb.h>
#include <pwd.h>
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
+#include <ctype.h>
+#include <limits.h>
#include "openbsd-compat/sys-queue.h"
-#include "key.h" /* XXX for typedef */
-#include "buffer.h" /* XXX for typedef */
#include "xmalloc.h"
-#include "match.h"
#include "ssherr.h"
#include "log.h"
-#include "canohost.h"
#include "sshbuf.h"
#include "misc.h"
-#include "channels.h"
-#include "servconf.h"
#include "sshkey.h"
+#include "match.h"
+#include "ssh2.h"
#include "auth-options.h"
-#include "hostfile.h"
-#include "auth.h"
-
-/* Flags set authorized_keys flags */
-int no_port_forwarding_flag = 0;
-int no_agent_forwarding_flag = 0;
-int no_x11_forwarding_flag = 0;
-int no_pty_flag = 0;
-int no_user_rc = 0;
-int key_is_cert_authority = 0;
-
-/* "command=" option. */
-char *forced_command = NULL;
-
-/* "environment=" options. */
-struct envstring *custom_environment = NULL;
-
-/* "tunnel=" option. */
-int forced_tun_device = -1;
-
-/* "principals=" option. */
-char *authorized_principals = NULL;
-
-extern ServerOptions options;
-
-void
-auth_clear_options(void)
-{
- no_agent_forwarding_flag = 0;
- no_port_forwarding_flag = 0;
- no_pty_flag = 0;
- no_x11_forwarding_flag = 0;
- no_user_rc = 0;
- key_is_cert_authority = 0;
- while (custom_environment) {
- struct envstring *ce = custom_environment;
- custom_environment = ce->next;
- free(ce->s);
- free(ce);
- }
- if (forced_command) {
- free(forced_command);
- forced_command = NULL;
- }
- if (authorized_principals) {
- free(authorized_principals);
- authorized_principals = NULL;
- }
- forced_tun_device = -1;
- channel_clear_permitted_opens();
-}
-/*
- * return 1 if access is granted, 0 if not.
- * side effect: sets key option flags
- */
-int
-auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
+static int
+dup_strings(char ***dstp, size_t *ndstp, char **src, size_t nsrc)
{
- const char *cp;
- int i;
+ char **dst;
+ size_t i, j;
- /* reset options */
- auth_clear_options();
+ *dstp = NULL;
+ *ndstp = 0;
+ if (nsrc == 0)
+ return 0;
- if (!opts)
- return 1;
-
- while (*opts && *opts != ' ' && *opts != '\t') {
- cp = "cert-authority";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- key_is_cert_authority = 1;
- opts += strlen(cp);
- goto next_option;
- }
- cp = "no-port-forwarding";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- auth_debug_add("Port forwarding disabled.");
- no_port_forwarding_flag = 1;
- opts += strlen(cp);
- goto next_option;
- }
- cp = "no-agent-forwarding";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- auth_debug_add("Agent forwarding disabled.");
- no_agent_forwarding_flag = 1;
- opts += strlen(cp);
- goto next_option;
- }
- cp = "no-X11-forwarding";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- auth_debug_add("X11 forwarding disabled.");
- no_x11_forwarding_flag = 1;
- opts += strlen(cp);
- goto next_option;
- }
- cp = "no-pty";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- auth_debug_add("Pty allocation disabled.");
- no_pty_flag = 1;
- opts += strlen(cp);
- goto next_option;
- }
- cp = "no-user-rc";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- auth_debug_add("User rc file execution disabled.");
- no_user_rc = 1;
- opts += strlen(cp);
- goto next_option;
- }
- cp = "command=\"";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- opts += strlen(cp);
- if (forced_command != NULL)
- free(forced_command);
- forced_command = xmalloc(strlen(opts) + 1);
- i = 0;
- while (*opts) {
- if (*opts == '"')
- break;
- if (*opts == '\\' && opts[1] == '"') {
- opts += 2;
- forced_command[i++] = '"';
- continue;
- }
- forced_command[i++] = *opts++;
- }
- if (!*opts) {
- debug("%.100s, line %lu: missing end quote",
- file, linenum);
- auth_debug_add("%.100s, line %lu: missing end quote",
- file, linenum);
- free(forced_command);
- forced_command = NULL;
- goto bad_option;
- }
- forced_command[i] = '\0';
- auth_debug_add("Forced command.");
- opts++;
- goto next_option;
- }
- cp = "principals=\"";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- opts += strlen(cp);
- if (authorized_principals != NULL)
- free(authorized_principals);
- authorized_principals = xmalloc(strlen(opts) + 1);
- i = 0;
- while (*opts) {
- if (*opts == '"')
- break;
- if (*opts == '\\' && opts[1] == '"') {
- opts += 2;
- authorized_principals[i++] = '"';
- continue;
- }
- authorized_principals[i++] = *opts++;
- }
- if (!*opts) {
- debug("%.100s, line %lu: missing end quote",
- file, linenum);
- auth_debug_add("%.100s, line %lu: missing end quote",
- file, linenum);
- free(authorized_principals);
- authorized_principals = NULL;
- goto bad_option;
- }
- authorized_principals[i] = '\0';
- auth_debug_add("principals: %.900s",
- authorized_principals);
- opts++;
- goto next_option;
- }
- cp = "environment=\"";
- if (options.permit_user_env &&
- strncasecmp(opts, cp, strlen(cp)) == 0) {
- char *s;
- struct envstring *new_envstring;
-
- opts += strlen(cp);
- s = xmalloc(strlen(opts) + 1);
- i = 0;
- while (*opts) {
- if (*opts == '"')
- break;
- if (*opts == '\\' && opts[1] == '"') {
- opts += 2;
- s[i++] = '"';
- continue;
- }
- s[i++] = *opts++;
- }
- if (!*opts) {
- debug("%.100s, line %lu: missing end quote",
- file, linenum);
- auth_debug_add("%.100s, line %lu: missing end quote",
- file, linenum);
- free(s);
- goto bad_option;
- }
- s[i] = '\0';
- auth_debug_add("Adding to environment: %.900s", s);
- debug("Adding to environment: %.900s", s);
- opts++;
- new_envstring = xcalloc(1, sizeof(struct envstring));
- new_envstring->s = s;
- new_envstring->next = custom_environment;
- custom_environment = new_envstring;
- goto next_option;
- }
- cp = "from=\"";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- const char *remote_ip = get_remote_ipaddr();
- const char *remote_host = get_canonical_hostname(
- options.use_dns);
- char *patterns = xmalloc(strlen(opts) + 1);
-
- opts += strlen(cp);
- i = 0;
- while (*opts) {
- if (*opts == '"')
- break;
- if (*opts == '\\' && opts[1] == '"') {
- opts += 2;
- patterns[i++] = '"';
- continue;
- }
- patterns[i++] = *opts++;
- }
- if (!*opts) {
- debug("%.100s, line %lu: missing end quote",
- file, linenum);
- auth_debug_add("%.100s, line %lu: missing end quote",
- file, linenum);
- free(patterns);
- goto bad_option;
- }
- patterns[i] = '\0';
- opts++;
- switch (match_host_and_ip(remote_host, remote_ip,
- patterns)) {
- case 1:
- free(patterns);
- /* Host name matches. */
- goto next_option;
- case -1:
- debug("%.100s, line %lu: invalid criteria",
- file, linenum);
- auth_debug_add("%.100s, line %lu: "
- "invalid criteria", file, linenum);
- /* FALLTHROUGH */
- case 0:
- free(patterns);
- logit("Authentication tried for %.100s with "
- "correct key but not from a permitted "
- "host (host=%.200s, ip=%.200s).",
- pw->pw_name, remote_host, remote_ip);
- auth_debug_add("Your host '%.200s' is not "
- "permitted to use this key for login.",
- remote_host);
- break;
- }
- /* deny access */
- return 0;
- }
- cp = "permitopen=\"";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- char *host, *p;
- int port;
- char *patterns = xmalloc(strlen(opts) + 1);
-
- opts += strlen(cp);
- i = 0;
- while (*opts) {
- if (*opts == '"')
- break;
- if (*opts == '\\' && opts[1] == '"') {
- opts += 2;
- patterns[i++] = '"';
- continue;
- }
- patterns[i++] = *opts++;
- }
- if (!*opts) {
- debug("%.100s, line %lu: missing end quote",
- file, linenum);
- auth_debug_add("%.100s, line %lu: missing "
- "end quote", file, linenum);
- free(patterns);
- goto bad_option;
- }
- patterns[i] = '\0';
- opts++;
- p = patterns;
- /* XXX - add streamlocal support */
- host = hpdelim(&p);
- if (host == NULL || strlen(host) >= NI_MAXHOST) {
- debug("%.100s, line %lu: Bad permitopen "
- "specification <%.100s>", file, linenum,
- patterns);
- auth_debug_add("%.100s, line %lu: "
- "Bad permitopen specification", file,
- linenum);
- free(patterns);
- goto bad_option;
- }
- host = cleanhostname(host);
- if (p == NULL || (port = permitopen_port(p)) < 0) {
- debug("%.100s, line %lu: Bad permitopen port "
- "<%.100s>", file, linenum, p ? p : "");
- auth_debug_add("%.100s, line %lu: "
- "Bad permitopen port", file, linenum);
- free(patterns);
- goto bad_option;
- }
- if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0)
- channel_add_permitted_opens(host, port);
- free(patterns);
- goto next_option;
- }
- cp = "tunnel=\"";
- if (strncasecmp(opts, cp, strlen(cp)) == 0) {
- char *tun = NULL;
- opts += strlen(cp);
- tun = xmalloc(strlen(opts) + 1);
- i = 0;
- while (*opts) {
- if (*opts == '"')
- break;
- tun[i++] = *opts++;
- }
- if (!*opts) {
- debug("%.100s, line %lu: missing end quote",
- file, linenum);
- auth_debug_add("%.100s, line %lu: missing end quote",
- file, linenum);
- free(tun);
- forced_tun_device = -1;
- goto bad_option;
- }
- tun[i] = '\0';
- forced_tun_device = a2tun(tun, NULL);
- free(tun);
- if (forced_tun_device == SSH_TUNID_ERR) {
- debug("%.100s, line %lu: invalid tun device",
- file, linenum);
- auth_debug_add("%.100s, line %lu: invalid tun device",
- file, linenum);
- forced_tun_device = -1;
- goto bad_option;
- }
- auth_debug_add("Forced tun device: %d", forced_tun_device);
- opts++;
- goto next_option;
+ if ((dst = calloc(nsrc, sizeof(*src))) == NULL)
+ return -1;
+ for (i = 0; i < nsrc; i++) {
+ if ((dst[i] = strdup(src[i])) == NULL) {
+ for (j = 0; j < i; j++)
+ free(dst[j]);
+ free(dst);
+ return -1;
}
-next_option:
- /*
- * Skip the comma, and move to the next option
- * (or break out if there are no more).
- */
- if (!*opts)
- fatal("Bugs in auth-options.c option processing.");
- if (*opts == ' ' || *opts == '\t')
- break; /* End of options. */
- if (*opts != ',')
- goto bad_option;
- opts++;
- /* Process the next option. */
}
-
- /* grant access */
- return 1;
-
-bad_option:
- logit("Bad options in %.100s file, line %lu: %.50s",
- file, linenum, opts);
- auth_debug_add("Bad options in %.100s file, line %lu: %.50s",
- file, linenum, opts);
-
- /* deny access */
+ /* success */
+ *dstp = dst;
+ *ndstp = nsrc;
return 0;
}
#define OPTIONS_CRITICAL 1
#define OPTIONS_EXTENSIONS 2
static int
-parse_option_list(struct sshbuf *oblob, struct passwd *pw,
- u_int which, int crit,
- int *cert_no_port_forwarding_flag,
- int *cert_no_agent_forwarding_flag,
- int *cert_no_x11_forwarding_flag,
- int *cert_no_pty_flag,
- int *cert_no_user_rc,
- char **cert_forced_command,
- int *cert_source_address_done)
+cert_option_list(struct sshauthopt *opts, struct sshbuf *oblob,
+ u_int which, int crit)
{
char *command, *allowed;
- const char *remote_ip;
char *name = NULL;
struct sshbuf *c = NULL, *data = NULL;
- int r, ret = -1, result, found;
+ int r, ret = -1, found;
if ((c = sshbuf_fromb(oblob)) == NULL) {
error("%s: sshbuf_fromb failed", __func__);
@@ -455,22 +96,25 @@ parse_option_list(struct sshbuf *oblob, struct passwd *pw,
name, sshbuf_len(data));
found = 0;
if ((which & OPTIONS_EXTENSIONS) != 0) {
- if (strcmp(name, "permit-X11-forwarding") == 0) {
- *cert_no_x11_forwarding_flag = 0;
+ if (strcmp(name, "no-touch-required") == 0) {
+ opts->no_require_user_presence = 1;
+ found = 1;
+ } else if (strcmp(name, "permit-X11-forwarding") == 0) {
+ opts->permit_x11_forwarding_flag = 1;
found = 1;
} else if (strcmp(name,
"permit-agent-forwarding") == 0) {
- *cert_no_agent_forwarding_flag = 0;
+ opts->permit_agent_forwarding_flag = 1;
found = 1;
} else if (strcmp(name,
"permit-port-forwarding") == 0) {
- *cert_no_port_forwarding_flag = 0;
+ opts->permit_port_forwarding_flag = 1;
found = 1;
} else if (strcmp(name, "permit-pty") == 0) {
- *cert_no_pty_flag = 0;
+ opts->permit_pty_flag = 1;
found = 1;
} else if (strcmp(name, "permit-user-rc") == 0) {
- *cert_no_user_rc = 0;
+ opts->permit_user_rc = 1;
found = 1;
}
}
@@ -482,13 +126,13 @@ parse_option_list(struct sshbuf *oblob, struct passwd *pw,
"section: %s", name, ssh_err(r));
goto out;
}
- if (*cert_forced_command != NULL) {
+ if (opts->force_command != NULL) {
error("Certificate has multiple "
"force-command options");
free(command);
goto out;
}
- *cert_forced_command = command;
+ opts->force_command = command;
found = 1;
}
if (strcmp(name, "source-address") == 0) {
@@ -498,38 +142,19 @@ parse_option_list(struct sshbuf *oblob, struct passwd *pw,
"section: %s", name, ssh_err(r));
goto out;
}
- if ((*cert_source_address_done)++) {
+ if (opts->required_from_host_cert != NULL) {
error("Certificate has multiple "
"source-address options");
free(allowed);
goto out;
}
- remote_ip = get_remote_ipaddr();
- result = addr_match_cidr_list(remote_ip,
- allowed);
- free(allowed);
- switch (result) {
- case 1:
- /* accepted */
- break;
- case 0:
- /* no match */
- logit("Authentication tried for %.100s "
- "with valid certificate but not "
- "from a permitted host "
- "(ip=%.200s).", pw->pw_name,
- remote_ip);
- auth_debug_add("Your address '%.200s' "
- "is not permitted to use this "
- "certificate for login.",
- remote_ip);
- goto out;
- case -1:
- default:
+ /* Check syntax */
+ if (addr_match_cidr_list(NULL, allowed) == -1) {
error("Certificate source-address "
"contents invalid");
goto out;
}
+ opts->required_from_host_cert = allowed;
found = 1;
}
}
@@ -555,75 +180,704 @@ parse_option_list(struct sshbuf *oblob, struct passwd *pw,
ret = 0;
out:
- if (ret != 0 &&
- cert_forced_command != NULL &&
- *cert_forced_command != NULL) {
- free(*cert_forced_command);
- *cert_forced_command = NULL;
- }
- if (name != NULL)
- free(name);
+ free(name);
sshbuf_free(data);
sshbuf_free(c);
return ret;
}
+struct sshauthopt *
+sshauthopt_new(void)
+{
+ struct sshauthopt *ret;
+
+ if ((ret = calloc(1, sizeof(*ret))) == NULL)
+ return NULL;
+ ret->force_tun_device = -1;
+ return ret;
+}
+
+void
+sshauthopt_free(struct sshauthopt *opts)
+{
+ size_t i;
+
+ if (opts == NULL)
+ return;
+
+ free(opts->cert_principals);
+ free(opts->force_command);
+ free(opts->required_from_host_cert);
+ free(opts->required_from_host_keys);
+
+ for (i = 0; i < opts->nenv; i++)
+ free(opts->env[i]);
+ free(opts->env);
+
+ for (i = 0; i < opts->npermitopen; i++)
+ free(opts->permitopen[i]);
+ free(opts->permitopen);
+
+ for (i = 0; i < opts->npermitlisten; i++)
+ free(opts->permitlisten[i]);
+ free(opts->permitlisten);
+
+ freezero(opts, sizeof(*opts));
+}
+
+struct sshauthopt *
+sshauthopt_new_with_keys_defaults(void)
+{
+ struct sshauthopt *ret = NULL;
+
+ if ((ret = sshauthopt_new()) == NULL)
+ return NULL;
+
+ /* Defaults for authorized_keys flags */
+ ret->permit_port_forwarding_flag = 1;
+ ret->permit_agent_forwarding_flag = 1;
+ ret->permit_x11_forwarding_flag = 1;
+ ret->permit_pty_flag = 1;
+ ret->permit_user_rc = 1;
+ return ret;
+}
+
/*
- * Set options from critical certificate options. These supersede user key
- * options so this must be called after auth_parse_options().
+ * Parse and record a permitopen/permitlisten directive.
+ * Return 0 on success. Return -1 on failure and sets *errstrp to error reason.
*/
-int
-auth_cert_options(struct sshkey *k, struct passwd *pw)
+static int
+handle_permit(const char **optsp, int allow_bare_port,
+ char ***permitsp, size_t *npermitsp, const char **errstrp)
{
- int cert_no_port_forwarding_flag = 1;
- int cert_no_agent_forwarding_flag = 1;
- int cert_no_x11_forwarding_flag = 1;
- int cert_no_pty_flag = 1;
- int cert_no_user_rc = 1;
- char *cert_forced_command = NULL;
- int cert_source_address_done = 0;
-
- if (sshkey_cert_is_legacy(k)) {
- /* All options are in the one field for v00 certs */
- if (parse_option_list(k->cert->critical, pw,
- OPTIONS_CRITICAL|OPTIONS_EXTENSIONS, 1,
- &cert_no_port_forwarding_flag,
- &cert_no_agent_forwarding_flag,
- &cert_no_x11_forwarding_flag,
- &cert_no_pty_flag,
- &cert_no_user_rc,
- &cert_forced_command,
- &cert_source_address_done) == -1)
- return -1;
- } else {
- /* Separate options and extensions for v01 certs */
- if (parse_option_list(k->cert->critical, pw,
- OPTIONS_CRITICAL, 1, NULL, NULL, NULL, NULL, NULL,
- &cert_forced_command,
- &cert_source_address_done) == -1)
- return -1;
- if (parse_option_list(k->cert->extensions, pw,
- OPTIONS_EXTENSIONS, 1,
- &cert_no_port_forwarding_flag,
- &cert_no_agent_forwarding_flag,
- &cert_no_x11_forwarding_flag,
- &cert_no_pty_flag,
- &cert_no_user_rc,
- NULL, NULL) == -1)
+ char *opt, *tmp, *cp, *host, **permits = *permitsp;
+ size_t npermits = *npermitsp;
+ const char *errstr = "unknown error";
+
+ if (npermits > SSH_AUTHOPT_PERMIT_MAX) {
+ *errstrp = "too many permission directives";
+ return -1;
+ }
+ if ((opt = opt_dequote(optsp, &errstr)) == NULL) {
+ return -1;
+ }
+ if (allow_bare_port && strchr(opt, ':') == NULL) {
+ /*
+ * Allow a bare port number in permitlisten to indicate a
+ * listen_host wildcard.
+ */
+ if (asprintf(&tmp, "*:%s", opt) == -1) {
+ free(opt);
+ *errstrp = "memory allocation failed";
return -1;
+ }
+ free(opt);
+ opt = tmp;
+ }
+ if ((tmp = strdup(opt)) == NULL) {
+ free(opt);
+ *errstrp = "memory allocation failed";
+ return -1;
+ }
+ cp = tmp;
+ /* validate syntax before recording it. */
+ host = hpdelim(&cp);
+ if (host == NULL || strlen(host) >= NI_MAXHOST) {
+ free(tmp);
+ free(opt);
+ *errstrp = "invalid permission hostname";
+ return -1;
+ }
+ /*
+ * don't want to use permitopen_port to avoid
+ * dependency on channels.[ch] here.
+ */
+ if (cp == NULL ||
+ (strcmp(cp, "*") != 0 && a2port(cp) <= 0)) {
+ free(tmp);
+ free(opt);
+ *errstrp = "invalid permission port";
+ return -1;
+ }
+ /* XXX - add streamlocal support */
+ free(tmp);
+ /* Record it */
+ if ((permits = recallocarray(permits, npermits, npermits + 1,
+ sizeof(*permits))) == NULL) {
+ free(opt);
+ /* NB. don't update *permitsp if alloc fails */
+ *errstrp = "memory allocation failed";
+ return -1;
+ }
+ permits[npermits++] = opt;
+ *permitsp = permits;
+ *npermitsp = npermits;
+ return 0;
+}
+
+struct sshauthopt *
+sshauthopt_parse(const char *opts, const char **errstrp)
+{
+ char **oarray, *opt, *cp, *tmp;
+ int r;
+ struct sshauthopt *ret = NULL;
+ const char *errstr = "unknown error";
+ uint64_t valid_before;
+
+ if (errstrp != NULL)
+ *errstrp = NULL;
+ if ((ret = sshauthopt_new_with_keys_defaults()) == NULL)
+ goto alloc_fail;
+
+ if (opts == NULL)
+ return ret;
+
+ while (*opts && *opts != ' ' && *opts != '\t') {
+ /* flag options */
+ if ((r = opt_flag("restrict", 0, &opts)) != -1) {
+ ret->restricted = 1;
+ ret->permit_port_forwarding_flag = 0;
+ ret->permit_agent_forwarding_flag = 0;
+ ret->permit_x11_forwarding_flag = 0;
+ ret->permit_pty_flag = 0;
+ ret->permit_user_rc = 0;
+ } else if ((r = opt_flag("cert-authority", 0, &opts)) != -1) {
+ ret->cert_authority = r;
+ } else if ((r = opt_flag("port-forwarding", 1, &opts)) != -1) {
+ ret->permit_port_forwarding_flag = r == 1;
+ } else if ((r = opt_flag("agent-forwarding", 1, &opts)) != -1) {
+ ret->permit_agent_forwarding_flag = r == 1;
+ } else if ((r = opt_flag("x11-forwarding", 1, &opts)) != -1) {
+ ret->permit_x11_forwarding_flag = r == 1;
+ } else if ((r = opt_flag("touch-required", 1, &opts)) != -1) {
+ ret->no_require_user_presence = r != 1; /* NB. flip */
+ } else if ((r = opt_flag("pty", 1, &opts)) != -1) {
+ ret->permit_pty_flag = r == 1;
+ } else if ((r = opt_flag("user-rc", 1, &opts)) != -1) {
+ ret->permit_user_rc = r == 1;
+ } else if (opt_match(&opts, "command")) {
+ if (ret->force_command != NULL) {
+ errstr = "multiple \"command\" clauses";
+ goto fail;
+ }
+ ret->force_command = opt_dequote(&opts, &errstr);
+ if (ret->force_command == NULL)
+ goto fail;
+ } else if (opt_match(&opts, "principals")) {
+ if (ret->cert_principals != NULL) {
+ errstr = "multiple \"principals\" clauses";
+ goto fail;
+ }
+ ret->cert_principals = opt_dequote(&opts, &errstr);
+ if (ret->cert_principals == NULL)
+ goto fail;
+ } else if (opt_match(&opts, "from")) {
+ if (ret->required_from_host_keys != NULL) {
+ errstr = "multiple \"from\" clauses";
+ goto fail;
+ }
+ ret->required_from_host_keys = opt_dequote(&opts,
+ &errstr);
+ if (ret->required_from_host_keys == NULL)
+ goto fail;
+ } else if (opt_match(&opts, "expiry-time")) {
+ if ((opt = opt_dequote(&opts, &errstr)) == NULL)
+ goto fail;
+ if (parse_absolute_time(opt, &valid_before) != 0 ||
+ valid_before == 0) {
+ free(opt);
+ errstr = "invalid expires time";
+ goto fail;
+ }
+ free(opt);
+ if (ret->valid_before == 0 ||
+ valid_before < ret->valid_before)
+ ret->valid_before = valid_before;
+ } else if (opt_match(&opts, "environment")) {
+ if (ret->nenv > INT_MAX) {
+ errstr = "too many environment strings";
+ goto fail;
+ }
+ if ((opt = opt_dequote(&opts, &errstr)) == NULL)
+ goto fail;
+ /* env name must be alphanumeric and followed by '=' */
+ if ((tmp = strchr(opt, '=')) == NULL) {
+ free(opt);
+ errstr = "invalid environment string";
+ goto fail;
+ }
+ if ((cp = strdup(opt)) == NULL)
+ goto alloc_fail;
+ cp[tmp - opt] = '\0'; /* truncate at '=' */
+ if (!valid_env_name(cp)) {
+ free(cp);
+ free(opt);
+ errstr = "invalid environment string";
+ goto fail;
+ }
+ free(cp);
+ /* Append it. */
+ oarray = ret->env;
+ if ((ret->env = recallocarray(ret->env, ret->nenv,
+ ret->nenv + 1, sizeof(*ret->env))) == NULL) {
+ free(opt);
+ ret->env = oarray; /* put it back for cleanup */
+ goto alloc_fail;
+ }
+ ret->env[ret->nenv++] = opt;
+ } else if (opt_match(&opts, "permitopen")) {
+ if (handle_permit(&opts, 0, &ret->permitopen,
+ &ret->npermitopen, &errstr) != 0)
+ goto fail;
+ } else if (opt_match(&opts, "permitlisten")) {
+ if (handle_permit(&opts, 1, &ret->permitlisten,
+ &ret->npermitlisten, &errstr) != 0)
+ goto fail;
+ } else if (opt_match(&opts, "tunnel")) {
+ if ((opt = opt_dequote(&opts, &errstr)) == NULL)
+ goto fail;
+ ret->force_tun_device = a2tun(opt, NULL);
+ free(opt);
+ if (ret->force_tun_device == SSH_TUNID_ERR) {
+ errstr = "invalid tun device";
+ goto fail;
+ }
+ }
+ /*
+ * Skip the comma, and move to the next option
+ * (or break out if there are no more).
+ */
+ if (*opts == '\0' || *opts == ' ' || *opts == '\t')
+ break; /* End of options. */
+ /* Anything other than a comma is an unknown option */
+ if (*opts != ',') {
+ errstr = "unknown key option";
+ goto fail;
+ }
+ opts++;
+ if (*opts == '\0') {
+ errstr = "unexpected end-of-options";
+ goto fail;
+ }
+ }
+
+ /* success */
+ if (errstrp != NULL)
+ *errstrp = NULL;
+ return ret;
+
+alloc_fail:
+ errstr = "memory allocation failed";
+fail:
+ sshauthopt_free(ret);
+ if (errstrp != NULL)
+ *errstrp = errstr;
+ return NULL;
+}
+
+struct sshauthopt *
+sshauthopt_from_cert(struct sshkey *k)
+{
+ struct sshauthopt *ret;
+
+ if (k == NULL || !sshkey_type_is_cert(k->type) || k->cert == NULL ||
+ k->cert->type != SSH2_CERT_TYPE_USER)
+ return NULL;
+
+ if ((ret = sshauthopt_new()) == NULL)
+ return NULL;
+
+ /* Handle options and critical extensions separately */
+ if (cert_option_list(ret, k->cert->critical,
+ OPTIONS_CRITICAL, 1) == -1) {
+ sshauthopt_free(ret);
+ return NULL;
+ }
+ if (cert_option_list(ret, k->cert->extensions,
+ OPTIONS_EXTENSIONS, 0) == -1) {
+ sshauthopt_free(ret);
+ return NULL;
+ }
+ /* success */
+ return ret;
+}
+
+/*
+ * Merges "additional" options to "primary" and returns the result.
+ * NB. Some options from primary have primacy.
+ */
+struct sshauthopt *
+sshauthopt_merge(const struct sshauthopt *primary,
+ const struct sshauthopt *additional, const char **errstrp)
+{
+ struct sshauthopt *ret;
+ const char *errstr = "internal error";
+ const char *tmp;
+
+ if (errstrp != NULL)
+ *errstrp = NULL;
+
+ if ((ret = sshauthopt_new()) == NULL)
+ goto alloc_fail;
+
+ /* cert_authority and cert_principals are cleared in result */
+
+ /* Prefer access lists from primary. */
+ /* XXX err is both set and mismatch? */
+ tmp = primary->required_from_host_cert;
+ if (tmp == NULL)
+ tmp = additional->required_from_host_cert;
+ if (tmp != NULL && (ret->required_from_host_cert = strdup(tmp)) == NULL)
+ goto alloc_fail;
+ tmp = primary->required_from_host_keys;
+ if (tmp == NULL)
+ tmp = additional->required_from_host_keys;
+ if (tmp != NULL && (ret->required_from_host_keys = strdup(tmp)) == NULL)
+ goto alloc_fail;
+
+ /*
+ * force_tun_device, permitopen/permitlisten and environment all
+ * prefer the primary.
+ */
+ ret->force_tun_device = primary->force_tun_device;
+ if (ret->force_tun_device == -1)
+ ret->force_tun_device = additional->force_tun_device;
+ if (primary->nenv > 0) {
+ if (dup_strings(&ret->env, &ret->nenv,
+ primary->env, primary->nenv) != 0)
+ goto alloc_fail;
+ } else if (additional->nenv) {
+ if (dup_strings(&ret->env, &ret->nenv,
+ additional->env, additional->nenv) != 0)
+ goto alloc_fail;
+ }
+ if (primary->npermitopen > 0) {
+ if (dup_strings(&ret->permitopen, &ret->npermitopen,
+ primary->permitopen, primary->npermitopen) != 0)
+ goto alloc_fail;
+ } else if (additional->npermitopen > 0) {
+ if (dup_strings(&ret->permitopen, &ret->npermitopen,
+ additional->permitopen, additional->npermitopen) != 0)
+ goto alloc_fail;
+ }
+
+ if (primary->npermitlisten > 0) {
+ if (dup_strings(&ret->permitlisten, &ret->npermitlisten,
+ primary->permitlisten, primary->npermitlisten) != 0)
+ goto alloc_fail;
+ } else if (additional->npermitlisten > 0) {
+ if (dup_strings(&ret->permitlisten, &ret->npermitlisten,
+ additional->permitlisten, additional->npermitlisten) != 0)
+ goto alloc_fail;
+ }
+
+#define OPTFLAG_AND(x) ret->x = (primary->x == 1) && (additional->x == 1)
+ /* Permissive flags are logical-AND (i.e. must be set in both) */
+ OPTFLAG_AND(permit_port_forwarding_flag);
+ OPTFLAG_AND(permit_agent_forwarding_flag);
+ OPTFLAG_AND(permit_x11_forwarding_flag);
+ OPTFLAG_AND(permit_pty_flag);
+ OPTFLAG_AND(permit_user_rc);
+ OPTFLAG_AND(no_require_user_presence);
+#undef OPTFLAG_AND
+
+ /* Earliest expiry time should win */
+ if (primary->valid_before != 0)
+ ret->valid_before = primary->valid_before;
+ if (additional->valid_before != 0 &&
+ additional->valid_before < ret->valid_before)
+ ret->valid_before = additional->valid_before;
+
+ /*
+ * When both multiple forced-command are specified, only
+ * proceed if they are identical, otherwise fail.
+ */
+ if (primary->force_command != NULL &&
+ additional->force_command != NULL) {
+ if (strcmp(primary->force_command,
+ additional->force_command) == 0) {
+ /* ok */
+ ret->force_command = strdup(primary->force_command);
+ if (ret->force_command == NULL)
+ goto alloc_fail;
+ } else {
+ errstr = "forced command options do not match";
+ goto fail;
+ }
+ } else if (primary->force_command != NULL) {
+ if ((ret->force_command = strdup(
+ primary->force_command)) == NULL)
+ goto alloc_fail;
+ } else if (additional->force_command != NULL) {
+ if ((ret->force_command = strdup(
+ additional->force_command)) == NULL)
+ goto alloc_fail;
+ }
+ /* success */
+ if (errstrp != NULL)
+ *errstrp = NULL;
+ return ret;
+
+ alloc_fail:
+ errstr = "memory allocation failed";
+ fail:
+ if (errstrp != NULL)
+ *errstrp = errstr;
+ sshauthopt_free(ret);
+ return NULL;
+}
+
+/*
+ * Copy options
+ */
+struct sshauthopt *
+sshauthopt_copy(const struct sshauthopt *orig)
+{
+ struct sshauthopt *ret;
+
+ if ((ret = sshauthopt_new()) == NULL)
+ return NULL;
+
+#define OPTSCALAR(x) ret->x = orig->x
+ OPTSCALAR(permit_port_forwarding_flag);
+ OPTSCALAR(permit_agent_forwarding_flag);
+ OPTSCALAR(permit_x11_forwarding_flag);
+ OPTSCALAR(permit_pty_flag);
+ OPTSCALAR(permit_user_rc);
+ OPTSCALAR(restricted);
+ OPTSCALAR(cert_authority);
+ OPTSCALAR(force_tun_device);
+ OPTSCALAR(valid_before);
+ OPTSCALAR(no_require_user_presence);
+#undef OPTSCALAR
+#define OPTSTRING(x) \
+ do { \
+ if (orig->x != NULL && (ret->x = strdup(orig->x)) == NULL) { \
+ sshauthopt_free(ret); \
+ return NULL; \
+ } \
+ } while (0)
+ OPTSTRING(cert_principals);
+ OPTSTRING(force_command);
+ OPTSTRING(required_from_host_cert);
+ OPTSTRING(required_from_host_keys);
+#undef OPTSTRING
+
+ if (dup_strings(&ret->env, &ret->nenv, orig->env, orig->nenv) != 0 ||
+ dup_strings(&ret->permitopen, &ret->npermitopen,
+ orig->permitopen, orig->npermitopen) != 0 ||
+ dup_strings(&ret->permitlisten, &ret->npermitlisten,
+ orig->permitlisten, orig->npermitlisten) != 0) {
+ sshauthopt_free(ret);
+ return NULL;
+ }
+ return ret;
+}
+
+static int
+serialise_array(struct sshbuf *m, char **a, size_t n)
+{
+ struct sshbuf *b;
+ size_t i;
+ int r;
+
+ if (n > INT_MAX)
+ return SSH_ERR_INTERNAL_ERROR;
+
+ if ((b = sshbuf_new()) == NULL) {
+ return SSH_ERR_ALLOC_FAIL;
+ }
+ for (i = 0; i < n; i++) {
+ if ((r = sshbuf_put_cstring(b, a[i])) != 0) {
+ sshbuf_free(b);
+ return r;
+ }
+ }
+ if ((r = sshbuf_put_u32(m, n)) != 0 ||
+ (r = sshbuf_put_stringb(m, b)) != 0) {
+ sshbuf_free(b);
+ return r;
}
+ /* success */
+ return 0;
+}
- no_port_forwarding_flag |= cert_no_port_forwarding_flag;
- no_agent_forwarding_flag |= cert_no_agent_forwarding_flag;
- no_x11_forwarding_flag |= cert_no_x11_forwarding_flag;
- no_pty_flag |= cert_no_pty_flag;
- no_user_rc |= cert_no_user_rc;
- /* CA-specified forced command supersedes key option */
- if (cert_forced_command != NULL) {
- if (forced_command != NULL)
- free(forced_command);
- forced_command = cert_forced_command;
+static int
+deserialise_array(struct sshbuf *m, char ***ap, size_t *np)
+{
+ char **a = NULL;
+ size_t i, n = 0;
+ struct sshbuf *b = NULL;
+ u_int tmp;
+ int r = SSH_ERR_INTERNAL_ERROR;
+
+ if ((r = sshbuf_get_u32(m, &tmp)) != 0 ||
+ (r = sshbuf_froms(m, &b)) != 0)
+ goto out;
+ if (tmp > INT_MAX) {
+ r = SSH_ERR_INVALID_FORMAT;
+ goto out;
}
+ n = tmp;
+ if (n > 0 && (a = calloc(n, sizeof(*a))) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ for (i = 0; i < n; i++) {
+ if ((r = sshbuf_get_cstring(b, &a[i], NULL)) != 0)
+ goto out;
+ }
+ /* success */
+ r = 0;
+ *ap = a;
+ a = NULL;
+ *np = n;
+ n = 0;
+ out:
+ if (a != NULL) {
+ for (i = 0; i < n; i++)
+ free(a[i]);
+ free(a);
+ }
+ sshbuf_free(b);
+ return r;
+}
+
+static int
+serialise_nullable_string(struct sshbuf *m, const char *s)
+{
+ int r;
+
+ if ((r = sshbuf_put_u8(m, s == NULL)) != 0 ||
+ (r = sshbuf_put_cstring(m, s)) != 0)
+ return r;
+ return 0;
+}
+
+static int
+deserialise_nullable_string(struct sshbuf *m, char **sp)
+{
+ int r;
+ u_char flag;
+
+ *sp = NULL;
+ if ((r = sshbuf_get_u8(m, &flag)) != 0 ||
+ (r = sshbuf_get_cstring(m, flag ? NULL : sp, NULL)) != 0)
+ return r;
return 0;
}
+int
+sshauthopt_serialise(const struct sshauthopt *opts, struct sshbuf *m,
+ int untrusted)
+{
+ int r = SSH_ERR_INTERNAL_ERROR;
+
+ /* Flag options */
+ if ((r = sshbuf_put_u8(m, opts->permit_port_forwarding_flag)) != 0 ||
+ (r = sshbuf_put_u8(m, opts->permit_agent_forwarding_flag)) != 0 ||
+ (r = sshbuf_put_u8(m, opts->permit_x11_forwarding_flag)) != 0 ||
+ (r = sshbuf_put_u8(m, opts->permit_pty_flag)) != 0 ||
+ (r = sshbuf_put_u8(m, opts->permit_user_rc)) != 0 ||
+ (r = sshbuf_put_u8(m, opts->restricted)) != 0 ||
+ (r = sshbuf_put_u8(m, opts->cert_authority)) != 0 ||
+ (r = sshbuf_put_u8(m, opts->no_require_user_presence)) != 0)
+ return r;
+
+ /* Simple integer options */
+ if ((r = sshbuf_put_u64(m, opts->valid_before)) != 0)
+ return r;
+
+ /* tunnel number can be negative to indicate "unset" */
+ if ((r = sshbuf_put_u8(m, opts->force_tun_device == -1)) != 0 ||
+ (r = sshbuf_put_u32(m, (opts->force_tun_device < 0) ?
+ 0 : (u_int)opts->force_tun_device)) != 0)
+ return r;
+
+ /* String options; these may be NULL */
+ if ((r = serialise_nullable_string(m,
+ untrusted ? "yes" : opts->cert_principals)) != 0 ||
+ (r = serialise_nullable_string(m,
+ untrusted ? "true" : opts->force_command)) != 0 ||
+ (r = serialise_nullable_string(m,
+ untrusted ? NULL : opts->required_from_host_cert)) != 0 ||
+ (r = serialise_nullable_string(m,
+ untrusted ? NULL : opts->required_from_host_keys)) != 0)
+ return r;
+
+ /* Array options */
+ if ((r = serialise_array(m, opts->env,
+ untrusted ? 0 : opts->nenv)) != 0 ||
+ (r = serialise_array(m, opts->permitopen,
+ untrusted ? 0 : opts->npermitopen)) != 0 ||
+ (r = serialise_array(m, opts->permitlisten,
+ untrusted ? 0 : opts->npermitlisten)) != 0)
+ return r;
+
+ /* success */
+ return 0;
+}
+
+int
+sshauthopt_deserialise(struct sshbuf *m, struct sshauthopt **optsp)
+{
+ struct sshauthopt *opts = NULL;
+ int r = SSH_ERR_INTERNAL_ERROR;
+ u_char f;
+ u_int tmp;
+
+ if ((opts = calloc(1, sizeof(*opts))) == NULL)
+ return SSH_ERR_ALLOC_FAIL;
+
+ /* Flag options */
+#define OPT_FLAG(x) \
+ do { \
+ if ((r = sshbuf_get_u8(m, &f)) != 0) \
+ goto out; \
+ opts->x = f; \
+ } while (0)
+ OPT_FLAG(permit_port_forwarding_flag);
+ OPT_FLAG(permit_agent_forwarding_flag);
+ OPT_FLAG(permit_x11_forwarding_flag);
+ OPT_FLAG(permit_pty_flag);
+ OPT_FLAG(permit_user_rc);
+ OPT_FLAG(restricted);
+ OPT_FLAG(cert_authority);
+ OPT_FLAG(no_require_user_presence);
+#undef OPT_FLAG
+
+ /* Simple integer options */
+ if ((r = sshbuf_get_u64(m, &opts->valid_before)) != 0)
+ goto out;
+
+ /* tunnel number can be negative to indicate "unset" */
+ if ((r = sshbuf_get_u8(m, &f)) != 0 ||
+ (r = sshbuf_get_u32(m, &tmp)) != 0)
+ goto out;
+ opts->force_tun_device = f ? -1 : (int)tmp;
+
+ /* String options may be NULL */
+ if ((r = deserialise_nullable_string(m, &opts->cert_principals)) != 0 ||
+ (r = deserialise_nullable_string(m, &opts->force_command)) != 0 ||
+ (r = deserialise_nullable_string(m,
+ &opts->required_from_host_cert)) != 0 ||
+ (r = deserialise_nullable_string(m,
+ &opts->required_from_host_keys)) != 0)
+ goto out;
+
+ /* Array options */
+ if ((r = deserialise_array(m, &opts->env, &opts->nenv)) != 0 ||
+ (r = deserialise_array(m,
+ &opts->permitopen, &opts->npermitopen)) != 0 ||
+ (r = deserialise_array(m,
+ &opts->permitlisten, &opts->npermitlisten)) != 0)
+ goto out;
+
+ /* success */
+ r = 0;
+ *optsp = opts;
+ opts = NULL;
+ out:
+ sshauthopt_free(opts);
+ return r;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-03 02:19:15 +0000