diff options
Diffstat (limited to 'lib/luks2/luks2_token_keyring.c')
| -rw-r--r-- | lib/luks2/luks2_token_keyring.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/lib/luks2/luks2_token_keyring.c b/lib/luks2/luks2_token_keyring.c new file mode 100644 index 0000000..be4f4a6 --- /dev/null +++ b/lib/luks2/luks2_token_keyring.c @@ -0,0 +1,170 @@ +/* + * LUKS - Linux Unified Key Setup v2, kernel keyring token + * + * Copyright (C) 2016-2021 Red Hat, Inc. All rights reserved. + * Copyright (C) 2016-2021 Ondrej Kozina + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <assert.h> + +#include "luks2_internal.h" + +static int keyring_open(struct crypt_device *cd, + int token, + char **buffer, + size_t *buffer_len, + void *usrptr __attribute__((unused))) +{ + json_object *jobj_token, *jobj_key; + struct luks2_hdr *hdr; + int r; + + if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2))) + return -EINVAL; + + jobj_token = LUKS2_get_token_jobj(hdr, token); + if (!jobj_token) + return -EINVAL; + + json_object_object_get_ex(jobj_token, "key_description", &jobj_key); + + r = keyring_get_passphrase(json_object_get_string(jobj_key), buffer, buffer_len); + if (r == -ENOTSUP) { + log_dbg(cd, "Kernel keyring features disabled."); + return -EINVAL; + } else if (r < 0) { + log_dbg(cd, "keyring_get_passphrase failed (error %d)", r); + return -EINVAL; + } + + return 0; +} + +static int keyring_validate(struct crypt_device *cd __attribute__((unused)), + const char *json) +{ + enum json_tokener_error jerr; + json_object *jobj_token, *jobj_key; + int r = 1; + + log_dbg(cd, "Validating keyring token json"); + + jobj_token = json_tokener_parse_verbose(json, &jerr); + if (!jobj_token) { + log_dbg(cd, "Keyring token JSON parse failed."); + return r; + } + + if (json_object_object_length(jobj_token) != 3) { + log_dbg(cd, "Keyring token is expected to have exactly 3 fields."); + goto out; + } + + if (!json_object_object_get_ex(jobj_token, "key_description", &jobj_key)) { + log_dbg(cd, "missing key_description field."); + goto out; + } + + if (!json_object_is_type(jobj_key, json_type_string)) { + log_dbg(cd, "key_description is not a string."); + goto out; + } + + /* TODO: perhaps check that key description is in '%s:%s' + * format where both strings are not empty */ + r = !strlen(json_object_get_string(jobj_key)); +out: + json_object_put(jobj_token); + return r; +} + +static void keyring_dump(struct crypt_device *cd, const char *json) +{ + enum json_tokener_error jerr; + json_object *jobj_token, *jobj_key; + + jobj_token = json_tokener_parse_verbose(json, &jerr); + if (!jobj_token) + return; + + if (!json_object_object_get_ex(jobj_token, "key_description", &jobj_key)) { + json_object_put(jobj_token); + return; + } + + log_std(cd, "\tKey description: %s\n", json_object_get_string(jobj_key)); + + json_object_put(jobj_token); +} + +int token_keyring_set(json_object **jobj_builtin_token, + const void *params) +{ + json_object *jobj_token, *jobj; + const struct crypt_token_params_luks2_keyring *keyring_params = (const struct crypt_token_params_luks2_keyring *) params; + + jobj_token = json_object_new_object(); + if (!jobj_token) + return -ENOMEM; + + jobj = json_object_new_string(LUKS2_TOKEN_KEYRING); + if (!jobj) { + json_object_put(jobj_token); + return -ENOMEM; + } + json_object_object_add(jobj_token, "type", jobj); + + jobj = json_object_new_array(); + if (!jobj) { + json_object_put(jobj_token); + return -ENOMEM; + } + json_object_object_add(jobj_token, "keyslots", jobj); + + jobj = json_object_new_string(keyring_params->key_description); + if (!jobj) { + json_object_put(jobj_token); + return -ENOMEM; + } + json_object_object_add(jobj_token, "key_description", jobj); + + *jobj_builtin_token = jobj_token; + return 0; +} + +int token_keyring_get(json_object *jobj_token, + void *params) +{ + json_object *jobj; + struct crypt_token_params_luks2_keyring *keyring_params = (struct crypt_token_params_luks2_keyring *) params; + + json_object_object_get_ex(jobj_token, "type", &jobj); + assert(!strcmp(json_object_get_string(jobj), LUKS2_TOKEN_KEYRING)); + + json_object_object_get_ex(jobj_token, "key_description", &jobj); + + keyring_params->key_description = json_object_get_string(jobj); + + return 0; +} + +const crypt_token_handler keyring_handler = { + .name = LUKS2_TOKEN_KEYRING, + .open = keyring_open, + .validate = keyring_validate, + .dump = keyring_dump +}; |