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-rw-r--r--auth-options.c909
1 files changed, 909 insertions, 0 deletions
diff --git a/auth-options.c b/auth-options.c
new file mode 100644
index 0000000..7cb2a64
--- /dev/null
+++ b/auth-options.c
@@ -0,0 +1,909 @@
+/* $OpenBSD: auth-options.c,v 1.98 2022/02/08 08:59:12 dtucker Exp $ */
+/*
+ * 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 "xmalloc.h"
+#include "ssherr.h"
+#include "log.h"
+#include "sshbuf.h"
+#include "misc.h"
+#include "sshkey.h"
+#include "match.h"
+#include "ssh2.h"
+#include "auth-options.h"
+
+static int
+dup_strings(char ***dstp, size_t *ndstp, char **src, size_t nsrc)
+{
+ char **dst;
+ size_t i, j;
+
+ *dstp = NULL;
+ *ndstp = 0;
+ if (nsrc == 0)
+ return 0;
+
+ 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;
+ }
+ }
+ /* success */
+ *dstp = dst;
+ *ndstp = nsrc;
+ return 0;
+}
+
+#define OPTIONS_CRITICAL 1
+#define OPTIONS_EXTENSIONS 2
+static int
+cert_option_list(struct sshauthopt *opts, struct sshbuf *oblob,
+ u_int which, int crit)
+{
+ char *command, *allowed;
+ char *name = NULL;
+ struct sshbuf *c = NULL, *data = NULL;
+ int r, ret = -1, found;
+
+ if ((c = sshbuf_fromb(oblob)) == NULL) {
+ error_f("sshbuf_fromb failed");
+ goto out;
+ }
+
+ while (sshbuf_len(c) > 0) {
+ sshbuf_free(data);
+ data = NULL;
+ if ((r = sshbuf_get_cstring(c, &name, NULL)) != 0 ||
+ (r = sshbuf_froms(c, &data)) != 0) {
+ error_r(r, "Unable to parse certificate options");
+ goto out;
+ }
+ debug3("found certificate option \"%.100s\" len %zu",
+ name, sshbuf_len(data));
+ found = 0;
+ if ((which & OPTIONS_EXTENSIONS) != 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) {
+ opts->permit_agent_forwarding_flag = 1;
+ found = 1;
+ } else if (strcmp(name,
+ "permit-port-forwarding") == 0) {
+ opts->permit_port_forwarding_flag = 1;
+ found = 1;
+ } else if (strcmp(name, "permit-pty") == 0) {
+ opts->permit_pty_flag = 1;
+ found = 1;
+ } else if (strcmp(name, "permit-user-rc") == 0) {
+ opts->permit_user_rc = 1;
+ found = 1;
+ }
+ }
+ if (!found && (which & OPTIONS_CRITICAL) != 0) {
+ if (strcmp(name, "verify-required") == 0) {
+ opts->require_verify = 1;
+ found = 1;
+ } else if (strcmp(name, "force-command") == 0) {
+ if ((r = sshbuf_get_cstring(data, &command,
+ NULL)) != 0) {
+ error_r(r, "Unable to parse \"%s\" "
+ "section", name);
+ goto out;
+ }
+ if (opts->force_command != NULL) {
+ error("Certificate has multiple "
+ "force-command options");
+ free(command);
+ goto out;
+ }
+ opts->force_command = command;
+ found = 1;
+ } else if (strcmp(name, "source-address") == 0) {
+ if ((r = sshbuf_get_cstring(data, &allowed,
+ NULL)) != 0) {
+ error_r(r, "Unable to parse \"%s\" "
+ "section", name);
+ goto out;
+ }
+ if (opts->required_from_host_cert != NULL) {
+ error("Certificate has multiple "
+ "source-address options");
+ free(allowed);
+ goto out;
+ }
+ /* 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;
+ }
+ }
+
+ if (!found) {
+ if (crit) {
+ error("Certificate critical option \"%s\" "
+ "is not supported", name);
+ goto out;
+ } else {
+ logit("Certificate extension \"%s\" "
+ "is not supported", name);
+ }
+ } else if (sshbuf_len(data) != 0) {
+ error("Certificate option \"%s\" corrupt "
+ "(extra data)", name);
+ goto out;
+ }
+ free(name);
+ name = NULL;
+ }
+ /* successfully parsed all options */
+ ret = 0;
+
+ out:
+ 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;
+}
+
+/*
+ * Parse and record a permitopen/permitlisten directive.
+ * Return 0 on success. Return -1 on failure and sets *errstrp to error reason.
+ */
+static int
+handle_permit(const char **optsp, int allow_bare_port,
+ char ***permitsp, size_t *npermitsp, const char **errstrp)
+{
+ 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 = hpdelim2(&cp, NULL);
+ 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;
+ size_t i, l;
+
+ 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("verify-required", 1, &opts)) != -1) {
+ ret->require_verify = r == 1;
+ } 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 > SSH_AUTHOPT_ENV_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) {
+ free(opt);
+ goto alloc_fail;
+ }
+ l = (size_t)(tmp - opt);
+ cp[l] = '\0'; /* truncate at '=' */
+ if (!valid_env_name(cp)) {
+ free(cp);
+ free(opt);
+ errstr = "invalid environment string";
+ goto fail;
+ }
+ /* Check for duplicates; XXX O(n*log(n)) */
+ for (i = 0; i < ret->nenv; i++) {
+ if (strncmp(ret->env[i], cp, l) == 0 &&
+ ret->env[i][l] == '=')
+ break;
+ }
+ free(cp);
+ /* First match wins */
+ if (i >= ret->nenv) {
+ /* Append it. */
+ oarray = ret->env;
+ if ((ret->env = recallocarray(ret->env,
+ ret->nenv, ret->nenv + 1,
+ sizeof(*ret->env))) == NULL) {
+ free(opt);
+ /* put it back for cleanup */
+ ret->env = oarray;
+ goto alloc_fail;
+ }
+ ret->env[ret->nenv++] = opt;
+ opt = NULL; /* transferred */
+ }
+ free(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)
+#define OPTFLAG_OR(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);
+ /* Restrictive flags are logical-OR (i.e. must be set in either) */
+ OPTFLAG_OR(require_verify);
+#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);
+ OPTSCALAR(require_verify);
+#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;
+}
+
+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 ||
+ (r = sshbuf_put_u8(m, opts->require_verify)) != 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);
+ OPT_FLAG(require_verify);
+#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 2.39.1) at 2024-11-17 15:54:45 +0000