Adding upstream version 2:2.3.7.upstream/2%2.3.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 650 insertions, 0 deletions

diff --git a/lib/luks2/luks2_token.c b/lib/luks2/luks2_token.c
new file mode 100644
index 0000000..9d0a889
--- /dev/null
+++ b/lib/luks2/luks2_token.c
@@ -0,0 +1,650 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, token handling
+ *
+ * Copyright (C) 2016-2021 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2016-2021 Milan Broz
+ *
+ * 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"
+
+/* Builtin tokens */
+extern const crypt_token_handler keyring_handler;
+
+static token_handler token_handlers[LUKS2_TOKENS_MAX] = {
+	/* keyring builtin token */
+	{
+	  .get = token_keyring_get,
+	  .set = token_keyring_set,
+	  .h = &keyring_handler
+	},
+};
+
+static int is_builtin_candidate(const char *type)
+{
+	return !strncmp(type, LUKS2_BUILTIN_TOKEN_PREFIX, LUKS2_BUILTIN_TOKEN_PREFIX_LEN);
+}
+
+int crypt_token_register(const crypt_token_handler *handler)
+{
+	int i;
+
+	if (is_builtin_candidate(handler->name)) {
+		log_dbg(NULL, "'" LUKS2_BUILTIN_TOKEN_PREFIX "' is reserved prefix for builtin tokens.");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < LUKS2_TOKENS_MAX && token_handlers[i].h; i++) {
+		if (!strcmp(token_handlers[i].h->name, handler->name)) {
+			log_dbg(NULL, "Keyslot handler %s is already registered.", handler->name);
+			return -EINVAL;
+		}
+	}
+
+	if (i == LUKS2_TOKENS_MAX)
+		return -EINVAL;
+
+	token_handlers[i].h = handler;
+	return 0;
+}
+
+static const token_handler
+*LUKS2_token_handler_type_internal(struct crypt_device *cd, const char *type)
+{
+	int i;
+
+	for (i = 0; i < LUKS2_TOKENS_MAX && token_handlers[i].h; i++)
+		if (!strcmp(token_handlers[i].h->name, type))
+			return token_handlers + i;
+
+	return NULL;
+}
+
+static const crypt_token_handler
+*LUKS2_token_handler_type(struct crypt_device *cd, const char *type)
+{
+	const token_handler *th = LUKS2_token_handler_type_internal(cd, type);
+
+	return th ? th->h : NULL;
+}
+
+static const token_handler
+*LUKS2_token_handler_internal(struct crypt_device *cd, int token)
+{
+	struct luks2_hdr *hdr;
+	json_object *jobj1, *jobj2;
+
+	if (token < 0)
+		return NULL;
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return NULL;
+
+	if (!(jobj1 = LUKS2_get_token_jobj(hdr, token)))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj1, "type", &jobj2))
+		return NULL;
+
+	return LUKS2_token_handler_type_internal(cd, json_object_get_string(jobj2));
+}
+
+static const crypt_token_handler
+*LUKS2_token_handler(struct crypt_device *cd, int token)
+{
+	const token_handler *th = LUKS2_token_handler_internal(cd, token);
+
+	return th ? th->h : NULL;
+}
+
+static int LUKS2_token_find_free(struct luks2_hdr *hdr)
+{
+	int i;
+
+	for (i = 0; i < LUKS2_TOKENS_MAX; i++)
+		if (!LUKS2_get_token_jobj(hdr, i))
+			return i;
+
+	return -EINVAL;
+}
+
+int LUKS2_token_create(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *json,
+	int commit)
+{
+	const crypt_token_handler *h;
+	const token_handler *th;
+	json_object *jobj_tokens, *jobj_type, *jobj;
+	enum json_tokener_error jerr;
+	char num[16];
+
+	if (token == CRYPT_ANY_TOKEN) {
+		if (!json)
+			return -EINVAL;
+		token = LUKS2_token_find_free(hdr);
+	}
+
+	if (token < 0 || token >= LUKS2_TOKENS_MAX)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "tokens", &jobj_tokens))
+		return -EINVAL;
+
+	if (snprintf(num, sizeof(num), "%d", token) < 0)
+		return -EINVAL;
+
+	/* Remove token */
+	if (!json)
+		json_object_object_del(jobj_tokens, num);
+	else {
+
+		jobj = json_tokener_parse_verbose(json, &jerr);
+		if (!jobj) {
+			log_dbg(cd, "Token JSON parse failed.");
+			return -EINVAL;
+		}
+
+		if (LUKS2_token_validate(cd, hdr->jobj, jobj, num)) {
+			json_object_put(jobj);
+			return -EINVAL;
+		}
+
+		json_object_object_get_ex(jobj, "type", &jobj_type);
+		if (is_builtin_candidate(json_object_get_string(jobj_type))) {
+			th = LUKS2_token_handler_type_internal(cd, json_object_get_string(jobj_type));
+			if (!th || !th->set) {
+				log_dbg(cd, "%s is builtin token candidate with missing handler", json_object_get_string(jobj_type));
+				json_object_put(jobj);
+				return -EINVAL;
+			}
+			h = th->h;
+		} else
+			h = LUKS2_token_handler_type(cd, json_object_get_string(jobj_type));
+
+		if (h && h->validate && h->validate(cd, json)) {
+			json_object_put(jobj);
+			log_dbg(cd, "Token type %s validation failed.", h->name);
+			return -EINVAL;
+		}
+
+		json_object_object_add(jobj_tokens, num, jobj);
+		if (LUKS2_check_json_size(cd, hdr)) {
+			log_dbg(cd, "Not enough space in header json area for new token.");
+			json_object_object_del(jobj_tokens, num);
+			return -ENOSPC;
+		}
+	}
+
+	if (commit)
+		return LUKS2_hdr_write(cd, hdr) ?: token;
+
+	return token;
+}
+
+crypt_token_info LUKS2_token_status(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char **type)
+{
+	const char *tmp;
+	const token_handler *th;
+	json_object *jobj_type, *jobj_token;
+
+	if (token < 0 || token >= LUKS2_TOKENS_MAX)
+		return CRYPT_TOKEN_INVALID;
+
+	if (!(jobj_token = LUKS2_get_token_jobj(hdr, token)))
+		return CRYPT_TOKEN_INACTIVE;
+
+	json_object_object_get_ex(jobj_token, "type", &jobj_type);
+	tmp = json_object_get_string(jobj_type);
+
+	if ((th = LUKS2_token_handler_type_internal(cd, tmp))) {
+		if (type)
+			*type = th->h->name;
+		return th->set ? CRYPT_TOKEN_INTERNAL : CRYPT_TOKEN_EXTERNAL;
+	}
+
+	if (type)
+		*type = tmp;
+
+	return is_builtin_candidate(tmp) ? CRYPT_TOKEN_INTERNAL_UNKNOWN : CRYPT_TOKEN_EXTERNAL_UNKNOWN;
+}
+
+int LUKS2_builtin_token_get(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *type,
+	void *params)
+{
+	const token_handler *th = LUKS2_token_handler_type_internal(cd, type);
+
+	// internal error
+	assert(th && th->get);
+
+	return th->get(LUKS2_get_token_jobj(hdr, token), params) ?: token;
+}
+
+int LUKS2_builtin_token_create(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *type,
+	const void *params,
+	int commit)
+{
+	const token_handler *th;
+	int r;
+	json_object *jobj_token, *jobj_tokens;
+
+	th = LUKS2_token_handler_type_internal(cd, type);
+
+	// at this point all builtin handlers must exist and have validate fn defined
+	assert(th && th->set && th->h->validate);
+
+	if (token == CRYPT_ANY_TOKEN) {
+		if ((token = LUKS2_token_find_free(hdr)) < 0)
+			log_err(cd, _("No free token slot."));
+	}
+	if (token < 0 || token >= LUKS2_TOKENS_MAX)
+		return -EINVAL;
+
+	r = th->set(&jobj_token, params);
+	if (r) {
+		log_err(cd, _("Failed to create builtin token %s."), type);
+		return r;
+	}
+
+	// builtin tokens must produce valid json
+	r = LUKS2_token_validate(cd, hdr->jobj, jobj_token, "new");
+	assert(!r);
+	r = th->h->validate(cd, json_object_to_json_string_ext(jobj_token,
+		JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE));
+	assert(!r);
+
+	json_object_object_get_ex(hdr->jobj, "tokens", &jobj_tokens);
+	json_object_object_add_by_uint(jobj_tokens, token, jobj_token);
+	if (LUKS2_check_json_size(cd, hdr)) {
+		log_dbg(cd, "Not enough space in header json area for new %s token.", type);
+		json_object_object_del_by_uint(jobj_tokens, token);
+		return -ENOSPC;
+	}
+
+	if (commit)
+		return LUKS2_hdr_write(cd, hdr) ?: token;
+
+	return token;
+}
+
+static int LUKS2_token_open(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	char **buffer,
+	size_t *buffer_len,
+	void *usrptr)
+{
+	const char *json;
+	const crypt_token_handler *h;
+	int r;
+
+	if (!(h = LUKS2_token_handler(cd, token)))
+		return -ENOENT;
+
+	if (h->validate) {
+		if (LUKS2_token_json_get(cd, hdr, token, &json))
+			return -EINVAL;
+
+		if (h->validate(cd, json)) {
+			log_dbg(cd, "Token %d (%s) validation failed.", token, h->name);
+			return -EINVAL;
+		}
+	}
+
+	r = h->open(cd, token, buffer, buffer_len, usrptr);
+	if (r < 0)
+		log_dbg(cd, "Token %d (%s) open failed with %d.", token, h->name, r);
+
+	return r;
+}
+
+static void LUKS2_token_buffer_free(struct crypt_device *cd,
+		int token,
+		void *buffer,
+		size_t buffer_len)
+{
+	const crypt_token_handler *h = LUKS2_token_handler(cd, token);
+
+	if (h && h->buffer_free)
+		h->buffer_free(buffer, buffer_len);
+	else {
+		crypt_safe_memzero(buffer, buffer_len);
+		free(buffer);
+	}
+}
+
+static int LUKS2_keyslot_open_by_token(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	int segment,
+	const char *buffer,
+	size_t buffer_len,
+	struct volume_key **vk)
+{
+	const crypt_token_handler *h;
+	json_object *jobj_token, *jobj_token_keyslots, *jobj;
+	unsigned int num = 0;
+	int i, r;
+
+	if (!(h = LUKS2_token_handler(cd, token)))
+		return -ENOENT;
+
+	jobj_token = LUKS2_get_token_jobj(hdr, token);
+	if (!jobj_token)
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_token, "keyslots", &jobj_token_keyslots);
+	if (!jobj_token_keyslots)
+		return -EINVAL;
+
+	/* Try to open keyslot referenced in token */
+	r = -EINVAL;
+	for (i = 0; i < (int) json_object_array_length(jobj_token_keyslots) && r < 0; i++) {
+		jobj = json_object_array_get_idx(jobj_token_keyslots, i);
+		num = atoi(json_object_get_string(jobj));
+		log_dbg(cd, "Trying to open keyslot %u with token %d (type %s).", num, token, h->name);
+		r = LUKS2_keyslot_open(cd, num, segment, buffer, buffer_len, vk);
+	}
+
+	if (r < 0)
+		return r;
+
+	return num;
+}
+
+int LUKS2_token_open_and_activate(struct crypt_device *cd,
+		struct luks2_hdr *hdr,
+		int token,
+		const char *name,
+		uint32_t flags,
+		void *usrptr)
+{
+	bool use_keyring;
+	int keyslot, r;
+	char *buffer;
+	size_t buffer_len;
+	struct volume_key *vk = NULL;
+
+	r = LUKS2_token_open(cd, hdr, token, &buffer, &buffer_len, usrptr);
+	if (r < 0)
+		return r;
+
+	r = LUKS2_keyslot_open_by_token(cd, hdr, token,
+					(flags & CRYPT_ACTIVATE_ALLOW_UNBOUND_KEY) ?
+					CRYPT_ANY_SEGMENT : CRYPT_DEFAULT_SEGMENT,
+					buffer, buffer_len, &vk);
+
+	LUKS2_token_buffer_free(cd, token, buffer, buffer_len);
+
+	if (r < 0)
+		return r;
+
+	keyslot = r;
+
+	if (!crypt_use_keyring_for_vk(cd))
+		use_keyring = false;
+	else
+		use_keyring = ((name && !crypt_is_cipher_null(crypt_get_cipher(cd))) ||
+			       (flags & CRYPT_ACTIVATE_KEYRING_KEY));
+
+	if (use_keyring) {
+		if (!(r = LUKS2_volume_key_load_in_keyring_by_keyslot(cd, hdr, vk, keyslot)))
+			flags |= CRYPT_ACTIVATE_KEYRING_KEY;
+	}
+
+	if (r >= 0 && name)
+		r = LUKS2_activate(cd, name, vk, flags);
+
+	if (r < 0)
+		crypt_drop_keyring_key(cd, vk);
+	crypt_free_volume_key(vk);
+
+	return r < 0 ? r : keyslot;
+}
+
+int LUKS2_token_open_and_activate_any(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	const char *name,
+	uint32_t flags)
+{
+	char *buffer;
+	json_object *tokens_jobj;
+	size_t buffer_len;
+	int keyslot, token, r = -EINVAL;
+	struct volume_key *vk = NULL;
+
+	json_object_object_get_ex(hdr->jobj, "tokens", &tokens_jobj);
+
+	json_object_object_foreach(tokens_jobj, slot, val) {
+		UNUSED(val);
+		token = atoi(slot);
+
+		r = LUKS2_token_open(cd, hdr, token, &buffer, &buffer_len, NULL);
+		if (r < 0)
+			continue;
+
+		r = LUKS2_keyslot_open_by_token(cd, hdr, token,
+						(flags & CRYPT_ACTIVATE_ALLOW_UNBOUND_KEY) ?
+						CRYPT_ANY_SEGMENT : CRYPT_DEFAULT_SEGMENT,
+						buffer, buffer_len, &vk);
+		LUKS2_token_buffer_free(cd, token, buffer, buffer_len);
+		if (r >= 0)
+			break;
+	}
+
+	keyslot = r;
+
+	if (r >= 0 && (name || (flags & CRYPT_ACTIVATE_KEYRING_KEY)) && crypt_use_keyring_for_vk(cd)) {
+		if (!(r = LUKS2_volume_key_load_in_keyring_by_keyslot(cd, hdr, vk, keyslot)))
+			flags |= CRYPT_ACTIVATE_KEYRING_KEY;
+	}
+
+	if (r >= 0 && name)
+		r = LUKS2_activate(cd, name, vk, flags);
+
+	if (r < 0)
+		crypt_drop_keyring_key(cd, vk);
+	crypt_free_volume_key(vk);
+
+	return r < 0 ? r : keyslot;
+}
+
+void LUKS2_token_dump(struct crypt_device *cd, int token)
+{
+	const crypt_token_handler *h;
+	json_object *jobj_token;
+
+	h = LUKS2_token_handler(cd, token);
+	if (h && h->dump) {
+		jobj_token = LUKS2_get_token_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), token);
+		if (jobj_token)
+			h->dump(cd, json_object_to_json_string_ext(jobj_token,
+				JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE));
+	}
+}
+
+int LUKS2_token_json_get(struct crypt_device *cd, struct luks2_hdr *hdr,
+			   int token, const char **json)
+{
+	json_object *jobj_token;
+
+	jobj_token = LUKS2_get_token_jobj(hdr, token);
+	if (!jobj_token)
+		return -EINVAL;
+
+	*json = json_object_to_json_string_ext(jobj_token,
+		JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE);
+	return 0;
+}
+
+static int assign_one_keyslot(struct crypt_device *cd, struct luks2_hdr *hdr,
+			      int token, int keyslot, int assign)
+{
+	json_object *jobj1, *jobj_token, *jobj_token_keyslots;
+	char num[16];
+
+	log_dbg(cd, "Keyslot %i %s token %i.", keyslot, assign ? "assigned to" : "unassigned from", token);
+
+	jobj_token = LUKS2_get_token_jobj(hdr, token);
+	if (!jobj_token)
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_token, "keyslots", &jobj_token_keyslots);
+	if (!jobj_token_keyslots)
+		return -EINVAL;
+
+	if (snprintf(num, sizeof(num), "%d", keyslot) < 0)
+		return -EINVAL;
+
+	if (assign) {
+		jobj1 = LUKS2_array_jobj(jobj_token_keyslots, num);
+		if (!jobj1)
+			json_object_array_add(jobj_token_keyslots, json_object_new_string(num));
+	} else {
+		jobj1 = LUKS2_array_remove(jobj_token_keyslots, num);
+		if (jobj1)
+			json_object_object_add(jobj_token, "keyslots", jobj1);
+	}
+
+	return 0;
+}
+
+static int assign_one_token(struct crypt_device *cd, struct luks2_hdr *hdr,
+			    int keyslot, int token, int assign)
+{
+	json_object *jobj_keyslots;
+	int r = 0;
+
+	if (!LUKS2_get_token_jobj(hdr, token))
+		return -EINVAL;
+
+	if (keyslot == CRYPT_ANY_SLOT) {
+		json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots);
+
+		json_object_object_foreach(jobj_keyslots, key, val) {
+			UNUSED(val);
+			r = assign_one_keyslot(cd, hdr, token, atoi(key), assign);
+			if (r < 0)
+				break;
+		}
+	} else
+		r = assign_one_keyslot(cd, hdr, token, keyslot, assign);
+
+	return r;
+}
+
+int LUKS2_token_assign(struct crypt_device *cd, struct luks2_hdr *hdr,
+			int keyslot, int token, int assign, int commit)
+{
+	json_object *jobj_tokens;
+	int r = 0;
+
+	if (token == CRYPT_ANY_TOKEN) {
+		json_object_object_get_ex(hdr->jobj, "tokens", &jobj_tokens);
+
+		json_object_object_foreach(jobj_tokens, key, val) {
+			UNUSED(val);
+			r = assign_one_token(cd, hdr, keyslot, atoi(key), assign);
+			if (r < 0)
+				break;
+		}
+	} else
+		r = assign_one_token(cd, hdr, keyslot, token, assign);
+
+	if (r < 0)
+		return r;
+
+	// FIXME: do not write header in nothing changed
+	if (commit)
+		return LUKS2_hdr_write(cd, hdr) ?: token;
+
+	return token;
+}
+
+static int token_is_assigned(struct luks2_hdr *hdr, int keyslot, int token)
+{
+	int i;
+	json_object *jobj, *jobj_token_keyslots,
+		    *jobj_token = LUKS2_get_token_jobj(hdr, token);
+
+	if (!jobj_token)
+		return -ENOENT;
+
+	json_object_object_get_ex(jobj_token, "keyslots", &jobj_token_keyslots);
+
+	for (i = 0; i < (int) json_object_array_length(jobj_token_keyslots); i++) {
+		jobj = json_object_array_get_idx(jobj_token_keyslots, i);
+		if (keyslot == atoi(json_object_get_string(jobj)))
+			return 0;
+	}
+
+	return -ENOENT;
+}
+
+int LUKS2_token_is_assigned(struct crypt_device *cd, struct luks2_hdr *hdr,
+			    int keyslot, int token)
+{
+	if (keyslot < 0 || keyslot >= LUKS2_KEYSLOTS_MAX || token < 0 || token >= LUKS2_TOKENS_MAX)
+		return -EINVAL;
+
+	return token_is_assigned(hdr, keyslot, token);
+}
+
+int LUKS2_tokens_count(struct luks2_hdr *hdr)
+{
+	json_object *jobj_tokens = LUKS2_get_tokens_jobj(hdr);
+	if (!jobj_tokens)
+		return -EINVAL;
+
+	return json_object_object_length(jobj_tokens);
+}
+
+int LUKS2_token_assignment_copy(struct crypt_device *cd,
+			struct luks2_hdr *hdr,
+			int keyslot_from,
+			int keyslot_to,
+			int commit)
+{
+	int i, r;
+
+	if (keyslot_from < 0 || keyslot_from >= LUKS2_KEYSLOTS_MAX || keyslot_to < 0 || keyslot_to >= LUKS2_KEYSLOTS_MAX)
+		return -EINVAL;
+
+	r = LUKS2_tokens_count(hdr);
+	if (r <= 0)
+		return r;
+
+	for (i = 0; i < LUKS2_TOKENS_MAX; i++) {
+		if (!token_is_assigned(hdr, keyslot_from, i)) {
+			if ((r = assign_one_token(cd, hdr, keyslot_to, i, 1)))
+				return r;
+		}
+	}
+
+	return commit ? LUKS2_hdr_write(cd, hdr) : 0;
+}