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) { struct ssh *ssh = active_state; /* XXX */ char *command, *allowed; const char *remote_ip; char *name = NULL; struct sshbuf *c = NULL, *data = NULL; int r, ret = -1, result, 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) { *cert_no_x11_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-agent-forwarding") == 0) { *cert_no_agent_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-port-forwarding") == 0) { *cert_no_port_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-pty") == 0) { *cert_no_pty_flag = 0; found = 1; } else if (strcmp(name, "permit-user-rc") == 0) { *cert_no_user_rc = 0; 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 (*cert_forced_command != NULL) { error("Certificate has multiple " "force-command options"); free(command); goto out; } *cert_forced_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 ((*cert_source_address_done)++) { error("Certificate has multiple " "source-address options"); free(allowed); goto out; } remote_ip = ssh_remote_ipaddr(ssh); 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: error("Certificate source-address " "contents invalid"); goto out; } 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: if (ret != 0 && cert_forced_command != NULL && *cert_forced_command != NULL) { free(*cert_forced_command); *cert_forced_command = NULL; } free(name); sshbuf_free(data); sshbuf_free(c); return ret; }
static int parse_option_list(u_char *optblob, size_t optblob_len, 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) { char *command, *allowed; const char *remote_ip; u_char *name = NULL, *data_blob = NULL; u_int nlen, dlen, clen; Buffer c, data; int ret = -1, found; buffer_init(&data); /* Make copy to avoid altering original */ buffer_init(&c); buffer_append(&c, optblob, optblob_len); while (buffer_len(&c) > 0) { if ((name = buffer_get_cstring_ret(&c, &nlen)) == NULL || (data_blob = buffer_get_string_ret(&c, &dlen)) == NULL) { error("Certificate options corrupt"); goto out; } buffer_append(&data, data_blob, dlen); debug3("found certificate option \"%.100s\" len %u", name, dlen); if (strlen(name) != nlen) { error("Certificate constraint name contains \\0"); goto out; } found = 0; if ((which & OPTIONS_EXTENSIONS) != 0) { if (strcmp(name, "permit-X11-forwarding") == 0) { *cert_no_x11_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-agent-forwarding") == 0) { *cert_no_agent_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-port-forwarding") == 0) { *cert_no_port_forwarding_flag = 0; found = 1; } else if (strcmp(name, "permit-pty") == 0) { *cert_no_pty_flag = 0; found = 1; } else if (strcmp(name, "permit-user-rc") == 0) { *cert_no_user_rc = 0; found = 1; } } if (!found && (which & OPTIONS_CRITICAL) != 0) { if (strcmp(name, "force-command") == 0) { if ((command = buffer_get_cstring_ret(&data, &clen)) == NULL) { error("Certificate constraint \"%s\" " "corrupt", name); goto out; } if (strlen(command) != clen) { error("force-command constraint " "contains \\0"); goto out; } if (*cert_forced_command != NULL) { error("Certificate has multiple " "force-command options"); xfree(command); goto out; } *cert_forced_command = command; found = 1; } if (strcmp(name, "source-address") == 0) { if ((allowed = buffer_get_cstring_ret(&data, &clen)) == NULL) { error("Certificate constraint " "\"%s\" corrupt", name); goto out; } if (strlen(allowed) != clen) { error("source-address constraint " "contains \\0"); goto out; } if ((*cert_source_address_done)++) { error("Certificate has multiple " "source-address options"); xfree(allowed); goto out; } remote_ip = get_remote_ipaddr(); switch (addr_match_cidr_list(remote_ip, allowed)) { case 1: /* accepted */ xfree(allowed); 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); xfree(allowed); goto out; case -1: error("Certificate source-address " "contents invalid"); xfree(allowed); goto out; } 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 (buffer_len(&data) != 0) { error("Certificate option \"%s\" corrupt " "(extra data)", name); goto out; } buffer_clear(&data); xfree(name); xfree(data_blob); name = data_blob = NULL; } /* successfully parsed all options */ ret = 0; out: if (ret != 0 && cert_forced_command != NULL && *cert_forced_command != NULL) { xfree(*cert_forced_command); *cert_forced_command = NULL; } if (name != NULL) xfree(name); if (data_blob != NULL) xfree(data_blob); buffer_free(&data); buffer_free(&c); return ret; }
int auth_authorise_keyopts(struct ssh *ssh, struct passwd *pw, struct sshauthopt *opts, int allow_cert_authority, const char *loc) { const char *remote_ip = ssh_remote_ipaddr(ssh); const char *remote_host = auth_get_canonical_hostname(ssh, options.use_dns); time_t now = time(NULL); char buf[64]; /* * Check keys/principals file expiry time. * NB. validity interval in certificate is handled elsewhere. */ if (opts->valid_before && now > 0 && opts->valid_before < (uint64_t)now) { format_absolute_time(opts->valid_before, buf, sizeof(buf)); debug("%s: entry expired at %s", loc, buf); auth_debug_add("%s: entry expired at %s", loc, buf); return -1; } /* Consistency checks */ if (opts->cert_principals != NULL && !opts->cert_authority) { debug("%s: principals on non-CA key", loc); auth_debug_add("%s: principals on non-CA key", loc); /* deny access */ return -1; } /* cert-authority flag isn't valid in authorized_principals files */ if (!allow_cert_authority && opts->cert_authority) { debug("%s: cert-authority flag invalid here", loc); auth_debug_add("%s: cert-authority flag invalid here", loc); /* deny access */ return -1; } /* Perform from= checks */ if (opts->required_from_host_keys != NULL) { switch (match_host_and_ip(remote_host, remote_ip, opts->required_from_host_keys )) { case 1: /* Host name matches. */ break; case -1: default: debug("%s: invalid from criteria", loc); auth_debug_add("%s: invalid from criteria", loc); /* FALLTHROUGH */ case 0: logit("%s: Authentication tried for %.100s with " "correct key but not from a permitted " "host (host=%.200s, ip=%.200s, required=%.200s).", loc, pw->pw_name, remote_host, remote_ip, opts->required_from_host_keys); auth_debug_add("%s: Your host '%.200s' is not " "permitted to use this key for login.", loc, remote_host); /* deny access */ return -1; } } /* Check source-address restriction from certificate */ if (opts->required_from_host_cert != NULL) { switch (addr_match_cidr_list(remote_ip, opts->required_from_host_cert)) { case 1: /* accepted */ break; case -1: default: /* invalid */ error("%s: Certificate source-address invalid", loc); /* FALLTHROUGH */ case 0: logit("%s: Authentication tried for %.100s with valid " "certificate but not from a permitted source " "address (%.200s).", loc, pw->pw_name, remote_ip); auth_debug_add("%s: Your address '%.200s' is not " "permitted to use this certificate for login.", loc, remote_ip); return -1; } } /* * * XXX this is spammy. We should report remotely only for keys * that are successful in actual auth attempts, and not PK_OK * tests. */ auth_log_authopts(loc, opts, 1); return 0; }
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; }