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;
}
/* Disable forwarding, etc for the session */
void
auth_restrict_session(struct ssh *ssh)
{
struct sshauthopt *restricted;
debug("%s: restricting session", __func__);
/* A blank sshauthopt defaults to permitting nothing */
restricted = sshauthopt_new();
restricted->permit_pty_flag = 1;
restricted->restricted = 1;
if (auth_activate_options(ssh, restricted) != 0)
fatal("%s: failed to restrict session", __func__);
sshauthopt_free(restricted);
}
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;
}
/*
* 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) {
sshauthopt_free(ret);
return NULL;
}
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 and environment 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;
}
/* 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;
}
