diff options
Diffstat (limited to 'auth-options.c')
| -rw-r--r-- | auth-options.c | 935 |
1 files changed, 935 insertions, 0 deletions
diff --git a/auth-options.c b/auth-options.c new file mode 100644 index 0000000..b05d6d6 --- /dev/null +++ b/auth-options.c @@ -0,0 +1,935 @@ +/* $OpenBSD: auth-options.c,v 1.84 2018/10/03 06:38:35 djm 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 <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" + +/* + * Match flag 'opt' in *optsp, and if allow_negate is set then also match + * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 + * if negated option matches. + * If the option or negated option matches, then *optsp is updated to + * point to the first character after the option. + */ +static int +opt_flag(const char *opt, int allow_negate, const char **optsp) +{ + size_t opt_len = strlen(opt); + const char *opts = *optsp; + int negate = 0; + + if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { + opts += 3; + negate = 1; + } + if (strncasecmp(opts, opt, opt_len) == 0) { + *optsp = opts + opt_len; + return negate ? 0 : 1; + } + return -1; +} + +static char * +opt_dequote(const char **sp, const char **errstrp) +{ + const char *s = *sp; + char *ret; + size_t i; + + *errstrp = NULL; + if (*s != '"') { + *errstrp = "missing start quote"; + return NULL; + } + s++; + if ((ret = malloc(strlen((s)) + 1)) == NULL) { + *errstrp = "memory allocation failed"; + return NULL; + } + for (i = 0; *s != '\0' && *s != '"';) { + if (s[0] == '\\' && s[1] == '"') + s++; + ret[i++] = *s++; + } + if (*s == '\0') { + *errstrp = "missing end quote"; + free(ret); + return NULL; + } + ret[i] = '\0'; + s++; + *sp = s; + return ret; +} + +static int +opt_match(const char **opts, const char *term) +{ + if (strncasecmp((*opts), term, strlen(term)) == 0 && + (*opts)[strlen(term)] == '=') { + *opts += strlen(term) + 1; + return 1; + } + return 0; +} + +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("%s: sshbuf_fromb failed", __func__); + 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("Unable to parse certificate options: %s", + ssh_err(r)); + goto out; + } + debug3("found certificate option \"%.100s\" len %zu", + name, sshbuf_len(data)); + found = 0; + if ((which & OPTIONS_EXTENSIONS) != 0) { + 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, "force-command") == 0) { + if ((r = sshbuf_get_cstring(data, &command, + NULL)) != 0) { + error("Unable to parse \"%s\" " + "section: %s", name, ssh_err(r)); + goto out; + } + if (opts->force_command != NULL) { + error("Certificate has multiple " + "force-command options"); + free(command); + goto out; + } + opts->force_command = command; + found = 1; + } + if (strcmp(name, "source-address") == 0) { + if ((r = sshbuf_get_cstring(data, &allowed, + NULL)) != 0) { + error("Unable to parse \"%s\" " + "section: %s", name, ssh_err(r)); + 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); + + explicit_bzero(opts, sizeof(*opts)); + free(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 > INT_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) < 0) { + *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("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; + } + + /* Flags are logical-AND (i.e. must be set in both for permission) */ +#define OPTFLAG(x) ret->x = (primary->x == 1) && (additional->x == 1) + OPTFLAG(permit_port_forwarding_flag); + OPTFLAG(permit_agent_forwarding_flag); + OPTFLAG(permit_x11_forwarding_flag); + OPTFLAG(permit_pty_flag); + OPTFLAG(permit_user_rc); +#undef OPTFLAG + + /* 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); +#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: + 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 and simple integer 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_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; + +#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); +#undef OPT_FLAG + + 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; +} |